Capture of trace sulfur gases from binary mixtures by single-walled carbon nanotube arrays: a molecular simulation study.

PubMed

Wang, Wenjuan; Peng, Xuan; Cao, Dapeng

2011-06-01

Adsorption of H(2)S and SO(2) pure gases and their selective capture from the H(2)S-CH(4), H(2)S-CO(2), SO(2)-N(2), and SO(2)-CO(2) binary mixtures by the single-walled carbon nanotubes (SWNT) are investigated via using the grand canonical Monte Carlo (GCMC) method. It is found that the (20, 20) SWNT with larger diameter shows larger capacity for H(2)S and SO(2) pure gases at T = 303 K, in which the uptakes reach 16.31 and 16.03 mmol/g, respectively. However, the (6,6) SWNT with small diameter exhibits the largest selectivity for binary mixtures containing trace sulfur gases at T = 303 K and P = 100 kPa. By investigating the effect of pore size on the separation of gas mixtures, we found that the optimized pore size is 0.81 nm for separation of H(2)S-CH(4), H(2)S-CO(2), and SO(2)-N(2) binary mixtures, while it is 1.09 nm for the SO(2)-CO(2) mixture. The effects of concentration and temperature on the selectivity of sulfide are also studied at the optimal pore size. It is found that the concentration (ppm) of sulfur components has little effect on selectivity of SWNTs for these binary mixtures. However, the selectivity decreases obviously with the increase of temperature. To improve the adsorption capacities, we further modify the surface of SWNTs with the functional groups. The selectivities of H(2)S-CO(2) and SO(2)-CO(2) mixtures are basically uninfluenced by the site density, while the increase of site density can improve the selectivity of H(2)S-CH(4) mixture doubly. It is expected that this work could provide useful information for sulfur gas capture.

Redox States of Initial Atmospheres Outgassed on Rocky Planets and Planetesimals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaefer, Laura; Fegley, Bruce Jr., E-mail: lschaefer@asu.edu

2017-07-10

The Earth and other rocky planets and planetesimals in the solar system formed through the mixing of materials from various radial locations in the solar nebula. This primordial material likely had a range of oxidation states as well as bulk compositions and volatile abundances. We investigate the oxygen fugacity produced by the outgassing of mixtures of solid meteoritic material, which approximate the primitive nebular materials. We find that the gas composition and oxygen fugacity of binary and ternary mixtures of meteoritic materials vary depending on the proportion of reduced versus oxidized material, and also find that mixtures using differentiated materialsmore » do not show the same oxygen fugacity trends as those using similarly reduced but undifferentiated materials. We also find that simply mixing the gases produced by individual meteoritic materials together does not correctly reproduce the gas composition or oxygen fugacity of the binary and ternary mixtures. We provide tabulated fits for the oxygen fugacities of all of the individual materials and binary mixtures that we investigate. These values may be useful in planetary formation models, models of volatile transport on planetesimals or meteorite parent bodies, or models of trace element partitioning during metal-silicate fractionation.« less

Quantitative decoding of the response a ceramic mixed potential sensor array for engine emissions control and diagnostics

DOE PAGES

Tsui, Lok-kun; Benavidez, Angelica; Palanisamy, Ponnusamy; ...

2017-04-13

The development of on-board sensors for emissions monitoring is necessary for continuous monitoring of the performance of catalytic systems in automobiles. We have fabricated mixed potential electrochemical gas sensing devices with Pt, La 0.8Sr 0.2CrO 3 (LSCO), and Au/Pd alloy electrodes and a porous yttria-stabilized zirconia electrolyte. The three-electrode design takes advantage of the preferential selectivity of the Pt + Au/Pd and Pt + LSCO pairs towards different species of gases and has additional tunable selectivity achieved by applying a current bias to the latter pair. Voltages were recorded in single, binary, and ternary gas streams of NO, NO 2,more » C 3H 8, and CO. We have also trained artificial neural networks to examine the voltage output from sensors in biased and unbiased modes to both identify which single test gas or binary mixture of two test gases is present in a gas stream as well as extract concentration values. We were then able to identify single and binary mixtures of these gases with accuracy of at least 98%. For determining concentration, the peak in the error distribution for binary mixtures was 5% and 80% of test data fell under <12% error. The sensor stability was also evaluated over the course of over 100 days and the ability to retrain ANNs with a small dataset was demonstrated.« less

Quantitative decoding of the response a ceramic mixed potential sensor array for engine emissions control and diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsui, Lok-kun; Benavidez, Angelica; Palanisamy, Ponnusamy

The development of on-board sensors for emissions monitoring is necessary for continuous monitoring of the performance of catalytic systems in automobiles. We have fabricated mixed potential electrochemical gas sensing devices with Pt, La 0.8Sr 0.2CrO 3 (LSCO), and Au/Pd alloy electrodes and a porous yttria-stabilized zirconia electrolyte. The three-electrode design takes advantage of the preferential selectivity of the Pt + Au/Pd and Pt + LSCO pairs towards different species of gases and has additional tunable selectivity achieved by applying a current bias to the latter pair. Voltages were recorded in single, binary, and ternary gas streams of NO, NO 2,more » C 3H 8, and CO. We have also trained artificial neural networks to examine the voltage output from sensors in biased and unbiased modes to both identify which single test gas or binary mixture of two test gases is present in a gas stream as well as extract concentration values. We were then able to identify single and binary mixtures of these gases with accuracy of at least 98%. For determining concentration, the peak in the error distribution for binary mixtures was 5% and 80% of test data fell under <12% error. The sensor stability was also evaluated over the course of over 100 days and the ability to retrain ANNs with a small dataset was demonstrated.« less

The calculation of the phase equilibrium of the multicomponent hydrocarbon systems

NASA Astrophysics Data System (ADS)

Molchanov, D. A.

2018-01-01

Hydrocarbon mixtures filtration process simulation development has resulted in use of cubic equations of state of the van der Waals type to describe the thermodynamic properties of natural fluids under real thermobaric conditions. Binary hydrocarbon systems allow to simulate the fluids of different types of reservoirs qualitatively, what makes it possible to carry out the experimental study of their filtration features. Exploitation of gas-condensate reservoirs shows the possibility of existence of various two-phase filtration regimes, including self-oscillatory one, which occurs under certain values of mixture composition, temperature and pressure drop. Plotting of the phase diagram of the model mixture is required to determine these values. A software package to calculate the vapor-liquid equilibrium of binary systems using cubic equation of state of the van der Waals type has been created. Phase diagrams of gas-condensate model mixtures have been calculated.

Configuration-specific kinetic theory applied to an ideal binary gas mixture.

PubMed

Wiseman, Floyd L

2006-10-05

This paper is the second in a two-part series dealing with the configuration-specific analyses for molecular collision events of hard, spherical molecules at thermal equilibrium. The first paper analyzed a single-component system, and the reader is referred to it for the fundamental concepts. In this paper, the expressions for the configuration-specific collision frequencies and the average line-of-centers collision angles and speeds are derived for an ideal binary gas mixture. The analyses show that the average line-of-centers quantities are all dependent upon the ratio of the masses of the two components, but not upon molecular size. Of course, the configuration-specific collision frequencies do depend on molecular size. The expression for the overall binary collision frequency is a simple sum of the configuration-specific collision frequencies and is identical to the conventional expression.

Discrete unified gas kinetic scheme for all Knudsen number flows. III. Binary gas mixtures of Maxwell molecules

NASA Astrophysics Data System (ADS)

Zhang, Yue; Zhu, Lianhua; Wang, Ruijie; Guo, Zhaoli

2018-05-01

Recently a discrete unified gas kinetic scheme (DUGKS) in a finite-volume formulation based on the Boltzmann model equation has been developed for gas flows in all flow regimes. The original DUGKS is designed for flows of single-species gases. In this work, we extend the DUGKS to flows of binary gas mixtures of Maxwell molecules based on the Andries-Aoki-Perthame kinetic model [P. Andries et al., J. Stat. Phys. 106, 993 (2002), 10.1023/A:1014033703134. A particular feature of the method is that the flux at each cell interface is evaluated based on the characteristic solution of the kinetic equation itself; thus the numerical dissipation is low in comparison with that using direct reconstruction. Furthermore, the implicit treatment of the collision term enables the time step to be free from the restriction of the relaxation time. Unlike the DUGKS for single-species flows, a nonlinear system must be solved to determine the interaction parameters appearing in the equilibrium distribution function, which can be obtained analytically for Maxwell molecules. Several tests are performed to validate the scheme, including the shock structure problem under different Mach numbers and molar concentrations, the channel flow driven by a small gradient of pressure, temperature, or concentration, the plane Couette flow, and the shear driven cavity flow under different mass ratios and molar concentrations. The results are compared with those from other reliable numerical methods. The results show that the proposed scheme is an effective and reliable method for binary gas mixtures in all flow regimes.

Multicomponent Gas Storage in Organic Cage Molecules

DOE PAGES

Zhang, Fei; He, Yadong; Huang, Jingsong; ...

2017-05-18

Porous liquids are a promising new class of materials featuring nanoscale cavity units dispersed in liquids that are suitable for applications such as gas storage and separation. In this work, we use molecular dynamics simulations to examine the multicomponent gas storage in a porous liquid consisting of crown-ether-substituted cage molecules dissolved in a 15-crown-5 solvent. We compute the storage of three prototypical small molecules including CO 2, CH 4, and N 2 and their binary mixtures in individual cage molecules. For porous liquids in equilibrium with a binary 1:1 gas mixture bath with partial gas pressure of 27.5 bar, amore » cage molecule shows a selectivity of 4.3 and 13.1 for the CO 2/CH 4 and CO 2/N 2 pairs, respectively. We provide a molecular perspective of how gas molecules are stored in the cage molecule and how the storage of one type of gas molecule is affected by other types of gas molecules. Finally, our results clarify the molecular mechanisms behind the selectivity of such cage molecules toward different gases.« less

Method for retorting oil shale

DOEpatents

Shang, Jer-Yu; Lui, A.P.

1985-08-16

The recovery of oil from oil shale is provided in a fluidized bed by using a fluidizing medium of a binary mixture of carbon dioxide and 5 steam. The mixture with a steam concentration in the range of about 20 to 75 volume percent steam provides an increase in oil yield over that achievable by using a fluidizing gas of carbon dioxide or steam alone when the mixture contains higher steam concentrations. The operating parameters for the fluidized bed retorted are essentially the same as those utilized with other gaseous fluidizing mediums with the significant gain being in the oil yield recovered which is attributable solely to the use of the binary mixture of carbon dioxide and steam. 2 figs.

Shear viscosity of binary mixtures: The Gay-Berne potential

NASA Astrophysics Data System (ADS)

Khordad, R.

2012-05-01

The Gay-Berne (GB) potential model is an interesting and useful model to study the real systems. Using the potential model, we intend to examine the thermodynamical properties of some anisotropic binary mixtures in two different phases, liquid and gas. For this purpose, we apply the integral equation method and solve numerically the Percus-Yevick (PY) integral equation. Then, we obtain the expansion coefficients of correlation functions to calculate the thermodynamical properties. Finally, we compare our results with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, benzene + methanol, cyclohexane + ethanol, benzene + ethanol, carbon tetrachloride + ethyl acetate, and methanol + ethanol]. The results show that the GB potential model is capable for predicting the thermodynamical properties of binary mixtures with acceptable accuracy.

Spectroscopic and Chemometric Analysis of Binary and Ternary Edible Oil Mixtures: Qualitative and Quantitative Study.

PubMed

Jović, Ozren; Smolić, Tomislav; Primožič, Ines; Hrenar, Tomica

2016-04-19

The aim of this study was to investigate the feasibility of FTIR-ATR spectroscopy coupled with the multivariate numerical methodology for qualitative and quantitative analysis of binary and ternary edible oil mixtures. Four pure oils (extra virgin olive oil, high oleic sunflower oil, rapeseed oil, and sunflower oil), as well as their 54 binary and 108 ternary mixtures, were analyzed using FTIR-ATR spectroscopy in combination with principal component and discriminant analysis, partial least-squares, and principal component regression. It was found that the composition of all 166 samples can be excellently represented using only the first three principal components describing 98.29% of total variance in the selected spectral range (3035-2989, 1170-1140, 1120-1100, 1093-1047, and 930-890 cm(-1)). Factor scores in 3D space spanned by these three principal components form a tetrahedral-like arrangement: pure oils being at the vertices, binary mixtures at the edges, and ternary mixtures on the faces of a tetrahedron. To confirm the validity of results, we applied several cross-validation methods. Quantitative analysis was performed by minimization of root-mean-square error of cross-validation values regarding the spectral range, derivative order, and choice of method (partial least-squares or principal component regression), which resulted in excellent predictions for test sets (R(2) > 0.99 in all cases). Additionally, experimentally more demanding gas chromatography analysis of fatty acid content was carried out for all specimens, confirming the results obtained by FTIR-ATR coupled with principal component analysis. However, FTIR-ATR provided a considerably better model for prediction of mixture composition than gas chromatography, especially for high oleic sunflower oil.

Densities and viscosities for binary mixtures of N-methyldiethanolamine + triethylene glycol monomethyl ether from 25 C to 70 C and N-methyldiethanolamine + ethanol mixtures at 40 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henni, A.; Maham, Y.; Tontiwachwuthikul, P.

2000-04-01

Recent studies done on the absorption and desorption of acid gases (CO{sub 2}, H{sub 2}S) from natural gas, petroleum, and ammonia synthesis streams have shown that aqueous solutions of N-methyldiethanolamine (MDEA) can be used effectively for the selective removal of H{sub 2}S. This paper reports the measured values of the density and viscosity of binary mixtures of N-methyldiethanolamine (MDEA) and triethylene glycol monomethyl ether (TEGMME) at five temperatures in the range 25 C to 70 C over the whole concentration range. The authors also report the density and viscosity of the binary mixture MDEA + ethanol at 40 C. Themore » results are compared with data for aqueous mixtures and other alkanolamines when these are available. The derived excess molar volumes and viscosity deviations were correlated as a function of composition. The Grunberg-Nissan interaction energy constants are also reported.« less

Floating liquid phase in sedimenting colloid-polymer mixtures.

PubMed

Schmidt, Matthias; Dijkstra, Marjolein; Hansen, Jean-Pierre

2004-08-20

Density functional theory and computer simulation are used to investigate sedimentation equilibria of colloid-polymer mixtures within the Asakura-Oosawa-Vrij model of hard sphere colloids and ideal polymers. When the ratio of buoyant masses of the two species is comparable to the ratio of differences in density of the coexisting bulk (colloid) gas and liquid phases, a stable "floating liquid" phase is found, i.e., a thin layer of liquid sandwiched between upper and lower gas phases. The full phase diagram of the mixture under gravity shows coexistence of this floating liquid phase with a single gas phase or a phase involving liquid-gas equilibrium; the phase coexistence lines meet at a triple point. This scenario remains valid for general asymmetric binary mixtures undergoing bulk phase separation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Fei; He, Yadong; Huang, Jingsong

Porous liquids are a promising new class of materials featuring nanoscale cavity units dispersed in liquids that are suitable for applications such as gas storage and separation. In this work, we use molecular dynamics simulations to examine the multicomponent gas storage in a porous liquid consisting of crown-ether-substituted cage molecules dissolved in a 15-crown-5 solvent. We compute the storage of three prototypical small molecules including CO 2, CH 4, and N 2 and their binary mixtures in individual cage molecules. For porous liquids in equilibrium with a binary 1:1 gas mixture bath with partial gas pressure of 27.5 bar, amore » cage molecule shows a selectivity of 4.3 and 13.1 for the CO 2/CH 4 and CO 2/N 2 pairs, respectively. We provide a molecular perspective of how gas molecules are stored in the cage molecule and how the storage of one type of gas molecule is affected by other types of gas molecules. Finally, our results clarify the molecular mechanisms behind the selectivity of such cage molecules toward different gases.« less

Viscosity and thermal conductivity of moderately dense gas mixtures.

NASA Technical Reports Server (NTRS)

Wakeham, W. A.; Kestin, J.; Mason, E. A.; Sandler, S. I.

1972-01-01

Derivation of a simple, semitheoretical expression for the initial density dependence of the viscosity and thermal conductivity of gaseous mixtures in terms of the appropriate properties of the pure components and of their interaction quantities. The derivation is based on Enskog's theory of dense gases and yields an equation in which the composition dependence of the linear factor in the density expansion is explicit. The interaction quantities are directly related to those of the mixture extrapolated to zero density and to a universal function valid for all gases. The reliability of the formulation is assessed with respect to the viscosity of several binary mixtures. It is found that the calculated viscosities of binary mixtures agree with the experimental data with a precision which is comparable to that of the most precise measurements.

Statistical mechanics of binary mixture adsorption in metal-organic frameworks in the osmotic ensemble.

PubMed

Dunne, Lawrence J; Manos, George

2018-03-13

Although crucial for designing separation processes little is known experimentally about multi-component adsorption isotherms in comparison with pure single components. Very few binary mixture adsorption isotherms are to be found in the literature and information about isotherms over a wide range of gas-phase composition and mechanical pressures and temperature is lacking. Here, we present a quasi-one-dimensional statistical mechanical model of binary mixture adsorption in metal-organic frameworks (MOFs) treated exactly by a transfer matrix method in the osmotic ensemble. The experimental parameter space may be very complex and investigations into multi-component mixture adsorption may be guided by theoretical insights. The approach successfully models breathing structural transitions induced by adsorption giving a good account of the shape of adsorption isotherms of CO 2 and CH 4 adsorption in MIL-53(Al). Binary mixture isotherms and co-adsorption-phase diagrams are also calculated and found to give a good description of the experimental trends in these properties and because of the wide model parameter range which reproduces this behaviour suggests that this is generic to MOFs. Finally, a study is made of the influence of mechanical pressure on the shape of CO 2 and CH 4 adsorption isotherms in MIL-53(Al). Quite modest mechanical pressures can induce significant changes to isotherm shapes in MOFs with implications for binary mixture separation processes.This article is part of the theme issue 'Modern theoretical chemistry'. © 2018 The Author(s).

Statistical mechanics of binary mixture adsorption in metal-organic frameworks in the osmotic ensemble

NASA Astrophysics Data System (ADS)

Dunne, Lawrence J.; Manos, George

2018-03-01

Although crucial for designing separation processes little is known experimentally about multi-component adsorption isotherms in comparison with pure single components. Very few binary mixture adsorption isotherms are to be found in the literature and information about isotherms over a wide range of gas-phase composition and mechanical pressures and temperature is lacking. Here, we present a quasi-one-dimensional statistical mechanical model of binary mixture adsorption in metal-organic frameworks (MOFs) treated exactly by a transfer matrix method in the osmotic ensemble. The experimental parameter space may be very complex and investigations into multi-component mixture adsorption may be guided by theoretical insights. The approach successfully models breathing structural transitions induced by adsorption giving a good account of the shape of adsorption isotherms of CO2 and CH4 adsorption in MIL-53(Al). Binary mixture isotherms and co-adsorption-phase diagrams are also calculated and found to give a good description of the experimental trends in these properties and because of the wide model parameter range which reproduces this behaviour suggests that this is generic to MOFs. Finally, a study is made of the influence of mechanical pressure on the shape of CO2 and CH4 adsorption isotherms in MIL-53(Al). Quite modest mechanical pressures can induce significant changes to isotherm shapes in MOFs with implications for binary mixture separation processes. This article is part of the theme issue `Modern theoretical chemistry'.

Analyte species and concentration identification using differentially functionalized microcantilever arrays and artificial neural networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senesac, Larry R; Datskos, Panos G; Sepaniak, Michael J

2006-01-01

In the present work, we have performed analyte species and concentration identification using an array of ten differentially functionalized microcantilevers coupled with a back-propagation artificial neural network pattern recognition algorithm. The array consists of ten nanostructured silicon microcantilevers functionalized by polymeric and gas chromatography phases and macrocyclic receptors as spatially dense, differentially responding sensing layers for identification and quantitation of individual analyte(s) and their binary mixtures. The array response (i.e. cantilever bending) to analyte vapor was measured by an optical readout scheme and the responses were recorded for a selection of individual analytes as well as several binary mixtures. Anmore » artificial neural network (ANN) was designed and trained to recognize not only the individual analytes and binary mixtures, but also to determine the concentration of individual components in a mixture. To the best of our knowledge, ANNs have not been applied to microcantilever array responses previously to determine concentrations of individual analytes. The trained ANN correctly identified the eleven test analyte(s) as individual components, most with probabilities greater than 97%, whereas it did not misidentify an unknown (untrained) analyte. Demonstrated unique aspects of this work include an ability to measure binary mixtures and provide both qualitative (identification) and quantitative (concentration) information with array-ANN-based sensor methodologies.« less

High pressure and temperature optical flow cell for near-infra-red spectroscopic analysis of gas mixtures.

PubMed

Norton, C G; Suedmeyer, J; Oderkerk, B; Fieback, T M

2014-05-01

A new optical flow cell with a new optical arrangement adapted for high pressures and temperatures using glass fibres to connect light source, cell, and spectrometer has been developed, as part of a larger project comprising new methods for in situ analysis of bio and hydrogen gas mixtures in high pressure and temperature applications. The analysis is based on measurements of optical, thermo-physical, and electromagnetic properties in gas mixtures with newly developed high pressure property sensors, which are mounted in a new apparatus which can generate gas mixtures with up to six components with an uncertainty of composition of as little as 0.1 mol. %. Measurements of several pure components of natural gases and biogases to a pressure of 20 MPa were performed on two isotherms, and with binary mixtures of the same pure gases at pressures to 17.5 MPa. Thereby a new method of analyzing the obtained spectra based on the partial density of methane was investigated.

Bioethanol production optimization: a thermodynamic analysis.

PubMed

Alvarez, Víctor H; Rivera, Elmer Ccopa; Costa, Aline C; Filho, Rubens Maciel; Wolf Maciel, Maria Regina; Aznar, Martín

2008-03-01

In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor-liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave-Redlich-Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems.

Development of mass measurement equipment using an electronic mass-comparator for gravimetric preparation of reference gas mixtures

NASA Astrophysics Data System (ADS)

Matsumoto, Nobuhiro; Watanabe, Takuro; Maruyama, Masaaki; Horimoto, Yoshiyuki; Maeda, Tsuneaki; Kato, Kenji

2004-06-01

The gravimetric method is the most popular method for preparing reference gas mixtures with high accuracy. We have designed and manufactured novel mass measurement equipment for gravimetric preparation of reference gas mixtures. This equipment consists of an electronic mass-comparator with a maximum capacity of 15 kg and readability of 1 mg and an automatic cylinder exchanger. The structure of this equipment is simpler and the cost is much lower than a conventional mechanical knife-edge type large balance used for gravimetric preparation of primary gas mixtures in Japan. This cylinder exchanger can mount two cylinders alternatively on the weighing pan of the comparator. In this study, the performance of the equipment has been evaluated. At first, the linearity and repeatability of the mass measurement were evaluated using standard mass pieces. Then, binary gas mixtures of propane and nitrogen were prepared and compared with those prepared with the conventional knife-edge type balance. The comparison resulted in good consistency at the compatibility criterion described in ISO6143:2001.

Thermodynamic evaluation of mass diffusion in ionic mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, Grigory; Tang, Xian-Zhu

2014-02-15

The thermodynamic technique of Landau and Lifshitz originally developed for inter-species diffusion in a binary neutral gas mixture is extended to a quasi-neutral plasma with two ion species. It is shown that, while baro- and electro-diffusion coefficients depend on the choice of the thermodynamic system, prediction for the total diffusive mass flux is invariant.

Heat transfer during condensation of steam from steam-gas mixtures in the passive safety systems of nuclear power plants

NASA Astrophysics Data System (ADS)

Portnova, N. M.; Smirnov, Yu B.

2017-11-01

A theoretical model for calculation of heat transfer during condensation of multicomponent vapor-gas mixtures on vertical surfaces, based on film theory and heat and mass transfer analogy is proposed. Calculations were performed for the conditions implemented in experimental studies of heat transfer during condensation of steam-gas mixtures in the passive safety systems of PWR-type reactors of different designs. Calculated values of heat transfer coefficients for condensation of steam-air, steam-air-helium and steam-air-hydrogen mixtures at pressures of 0.2 to 0.6 MPa and of steam-nitrogen mixture at the pressures of 0.4 to 2.6 MPa were obtained. The composition of mixtures and vapor-to-surface temperature difference were varied within wide limits. Tube length ranged from 0.65 to 9.79m. The condensation of all steam-gas mixtures took place in a laminar-wave flow mode of condensate film and turbulent free convection in the diffusion boundary layer. The heat transfer coefficients obtained by calculation using the proposed model are in good agreement with the considered experimental data for both the binary and ternary mixtures.

A study of nonflammable ArCO 2-hydrocarbon gas mixtures for limited streamer tubes

NASA Astrophysics Data System (ADS)

Cartwright, S.; Schneekloth, U.; Alpat, B.; Artemi, C.; Battiston, R.; Bilei, G.; Italiani, M.; Pauluzzi, M.; Servoli, L.; Messner, R.; Wyss, J.; Zdarko, R.; Johnson, J.

1989-04-01

The gas mixtures generally used until now in limited streamer tube detectors (Ar+C 4H 10 or Ar+CO 2+C 5H 12) are very flammable when leaked into air. The safety issues are therefore very relevant for large-volume underground experiments. We have found a set of completely safe (i.e. nonflammable) ternary mixtures of the kind Ar + hydrocarbon + CO 2 containing less than ˜ 5% of Ar and less than ˜ 10% of hydrocarbon. We tested C 4H 10, C 5H 12 and C 6H 14 as quenching agents. The main characteristics of the various mixtures have been measured: singles (untriggered) counting rate versus high voltage and with different dead times, and average charge. The stability of these mixtures is good, and their spurious streamer activity is compared with the standard binary or ternary mixture. We studied in particular the combination Ar(2.5%) + C 4H 10(9.5%) + CO 2(88%). All the data suggest that this or a similar gas mixture can successfully replace standard flammable mixtures both in tracking devices and hadron calorimeters.

A simple thermodynamic model useful for calculating gas solubilities in water/brine/hydrocarbon mixtures from 0 to 250 C and 1 to 150 bars

NASA Astrophysics Data System (ADS)

Perez, R. J.; Shevalier, M.; Hutcheon, I.

2004-05-01

Gas solubility is of considerable interest, not only for the theoretical understanding of vapor-liquid equilibria, but also due to extensive applications in combined geochemical, engineering, and environmental problems, such as greenhouse gas sequestration. Reliable models for gas solubility calculations in salt waters and hydrocarbons are also valuable when evaluating fluid inclusions saturated with gas components. We have modeled the solubility of methane, ethane, hydrogen, carbon dioxide, hydrogen sulfide, and five other gases in a water-brine-hydrocarbon system by solving a non-linear system of equations composed by modified Henry's Law Constants (HLC), gas fugacities, and assuming binary mixtures. HLCs are a function of pressure, temperature, brine salinity, and hydrocarbon density. Experimental data of vapor pressures and mutual solubilities of binary mixtures provide the basis for the calibration of the proposed model. It is demonstrated that, by using the Setchenow equation, only a relatively simple modification of the pure water model is required to assess the solubility of gases in brine solutions. Henry's Law constants for gases in hydrocarbons are derived using regular solution theory and Ostwald coefficients available from the literature. We present a set of two-parameter polynomial expressions, which allow simple computation and formulation of the model. Our calculations show that solubility predictions using modified HLCs are acceptable within 0 to 250 C, 1 to 150 bars, salinity up to 5 molar, and gas concentrations up to 4 molar. Our model is currently being used in the IEA Weyburn CO2 monitoring and storage project.

Theory of anomalous critical-cluster content in high-pressure binary nucleation.

PubMed

Kalikmanov, V I; Labetski, D G

2007-02-23

Nucleation experiments in binary (a-b) mixtures, when component a is supersaturated and b (carrier gas) is undersaturated, reveal that for some mixtures at high pressures the a content of the critical cluster dramatically decreases with pressure contrary to expectations based on classical nucleation theory. We show that this phenomenon is a manifestation of the dominant role of the unlike interactions at high pressures resulting in the negative partial molar volume of component a in the vapor phase beyond the compensation pressure. The analysis is based on the pressure nucleation theorem for multicomponent systems which is invariant to a nucleation model.

Prediction of vapour-liquid and vapour-liquid-liquid equilibria of nitrogen-hydrocarbon mixtures used in J-T refrigerators

NASA Astrophysics Data System (ADS)

Narayanan, Vineed; Venkatarathnam, G.

2018-03-01

Nitrogen-hydrocarbon mixtures are widely used as refrigerants in J-T refrigerators operating with mixtures, as well as in natural gas liquefiers. The Peng-Robinson equation of state has traditionally been used to simulate the above cryogenic process. Multi parameter Helmholtz energy equations are now preferred for determining the properties of natural gas. They have, however, been used only to predict vapour-liquid equilibria, and not vapour-liquid-liquid equilibria that can occur in mixtures used in cryogenic mixed refrigerant processes. In this paper the vapour-liquid equilibrium of binary mixtures of nitrogen-methane, nitrogen-ethane, nitrogen-propane, nitrogen-isobutane and three component mixtures of nitrogen-methane-ethane and nitrogen-methane-propane have been studied with the Peng-Robinson and the Helmholtz energy equations of state of NIST REFPROP and compared with experimental data available in the literature.

Gas engineering studies for high pressure self-sustained diffuse discharge closing switches

NASA Astrophysics Data System (ADS)

Hunter, S. R.; Christophorou, L. G.; Carter, J. G.

The operating voltage and discharge stability of diffuse discharges for fast-closing switch applications are critically dependent on the variation of the ionization (alpha/N) and attachment (eta/N) coefficients with E/N (gas density normalized electric field strength). Gases and gas mixtures which possess low (E/N)/sub lim/ values (i.e., the E/N value when anti alpha/N = alpha/N - eta/N = 0) and effective ionization coefficients, anti alpha/N, which vary slowly with E/N near (E/N)(sub lim) lead to lower voltage (i.e., more efficient) operation with increased discharge stability. Several gas mixtures with these characteristics are discussed. It is argued that further improvements in switch efficiency and discharge stability can be obtained by adding a low ionization onset gas additive to these binary mixtures, such that at low E/N, alpha/N is greater than eta/N, while at higher E/N, eta/N is greater than alpha/N over a restricted E/N range. Several low ionization onset gas additives are suggested and the electron attachment and ionization coefficients in selected gas mixtures which possess these desirable characteristics are given.

An experimental study of adsorption interference in binary mixtures flowing through activated carbon

NASA Technical Reports Server (NTRS)

Madey, R.; Photinos, P. J.

1983-01-01

The isothermal transmission through activated carbon adsorber beds at 25 C of acetaldehyde-propane and acetylene-ethane mixtures in a helium carrier gas was measured. The inlet concentration of each component was in the range between 10 ppm and 500 ppm. The constant inlet volumetric flow rate was controlled at 200 cc (STP)/min in the acetaldehyde-propane experiments and at 50 cc (STP)/min in the acetaldehyde-ethane experiments. Comparison of experimental results with the corresponding single-component experiments under similar conditions reveals interference phenomena between the components of the mixtures as evidenced by changes in both the adsorption capacity and the dispersion number. Propane was found to displace acetaldehyde from the adsorbed state. The outlet concentration profiles of propane in the binary mixtures tend to become more diffuse than the corresponding concentration profiles of the one-component experiments. Similar features were observed with mixtures of acetylene and ethane; however, the displacement of acetylene by ethane is less pronounced.

Efficient capture of SO2 by a binary mixture of caprolactam tetrabutyl ammonium bromide ionic liquid and water.

PubMed

Duan, Erhong; Guo, Bin; Zhang, Miaomiao; Guan, Yanan; Sun, Hua; Han, Jing

2011-10-30

The solubility of SO(2) in a binary mixture of water and caprolactam tetrabutyl ammonium bromide ionic liquid (CPL-TBAB IL) was investigated. Though the ionic liquid and water were fully miscible, a phase separation occurred when SO(2) was introduced into the mixture. The SO(2) concentrated in the lower layer, and it could be released by heating the solution under reduced pressure (382.2K, 10.1 kPa). After desorption, the mixture could be reused to absorb SO(2). It was found that SO(2) acts as a switch to cause the water and CPL-TBAB IL to phase separate, and the mechanics of this phase separation process was studied by gas chromatography-mass spectrometry, fourier transform-infrared spectroscopy and Karl-Fisher titration. The absorption and desorption of SO(2) in the CPL-TBAB/water mixtures were reversible. Copyright © 2011 Elsevier B.V. All rights reserved.

International comparison Euramet.QM-K111—propane in nitrogen

NASA Astrophysics Data System (ADS)

Wouter van der Hout, J.; van der Veen, Adriaan M. H.; Ziel, Paul R.; Kipphardt, Heinrich; Tuma, Dirk; Maiwald, Michael; Fernández, Teresa E.; Gómez, Concepción; Cieciora, Dariusz; Ochman, Grzegorz; Dias, Florbela; Silvino, Victor; Macé, Tatiana; Sutour, Christophe; Marioni, Fabrice; Ackermann, Andreas; Niederhauser, Bernhard; Fükő, Judit; Büki, Tamás; Nagyné Szilágyi, Zsófia; Tarhan, Tanıl; Engin, Erinç

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capabilities to prepare Primary Standard gas Mixtures (PSMs), perform the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this key comparison is classified as an RMO track A key comparison. The artefacts were binary mixtures of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The results are generally good. All results are within +/- 1 % of the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The compressibility and the capacitance coefficient of helium-oxygen atmospheres.

PubMed

Imbert, G; Dejours, P; Hildwein, G

1982-12-01

The capacitance coefficient beta of an ideal gas mixture depends only on its temperature T, and its value is derived from the ideal gas law (i.e., beta = 1/RT, R being the ideal gas constant). But real gases behave as ideal gases only at low pressures, and this would not be the case in deep diving. High pressures of helium-oxygen are used in human and animal experimental dives (up to 7 or 12 MPa or more, respectively). At such pressures deviations from the ideal gas law cannot be neglected in hyperbaric atmospheres with respect to current accuracy of measuring instruments. As shown both theoretically and experimentally by this study, the non-ideal nature of helium-oxygen has a significant effect on the capacitance coefficient of hyperbaric atmospheres. The theoretical study is based on interaction energy in either homogeneous (He-He and O2-O2) or heterogeneous (He-O2) molecular pairs, and on the virial equation of state for gas mixtures. The experimental study is based on weight determination of samples of known volume of binary helium-oxygen mixtures, which are prepared in well-controlled pressure and temperature conditions. Our experimental results are in good agreement with theoretical predictions. 1) The helium compressibility factor ZHe increases linearly with pressure [ZHe = 1 + 0.0045 P (in MPa) at 30 degrees C]; and 2) in same temperature and pressure conditions (T = 303 K and P = 0.1 to 15 MPa), the same value for Z is valid for a helium-oxygen binary mixture and for pure helium. As derived from the equation of state of real gases, the capacitance coefficient is inversely related to Z (beta = 1/ZRT); therefore, for helium-oxygen mixtures, this coefficient would decrease with increasing pressure. A table is given for theoretical values of helium-oxygen capacitance coefficient, at pressures ranging from 0.1 to 15.0 MPa and at temperatures ranging from 25 degrees C to 37 degrees C.

An odor interaction model of binary odorant mixtures by a partial differential equation method.

PubMed

Yan, Luchun; Liu, Jiemin; Wang, Guihua; Wu, Chuandong

2014-07-09

A novel odor interaction model was proposed for binary mixtures of benzene and substituted benzenes by a partial differential equation (PDE) method. Based on the measurement method (tangent-intercept method) of partial molar volume, original parameters of corresponding formulas were reasonably displaced by perceptual measures. By these substitutions, it was possible to relate a mixture's odor intensity to the individual odorant's relative odor activity value (OAV). Several binary mixtures of benzene and substituted benzenes were respectively tested to establish the PDE models. The obtained results showed that the PDE model provided an easily interpretable method relating individual components to their joint odor intensity. Besides, both predictive performance and feasibility of the PDE model were proved well through a series of odor intensity matching tests. If combining the PDE model with portable gas detectors or on-line monitoring systems, olfactory evaluation of odor intensity will be achieved by instruments instead of odor assessors. Many disadvantages (e.g., expense on a fixed number of odor assessors) also will be successfully avoided. Thus, the PDE model is predicted to be helpful to the monitoring and management of odor pollutions.

Hot gas, regenerative, supported H.sub.2 S sorbents

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor); Sharma, Pramod K. (Inventor)

1993-01-01

Efficient, regenerable sorbents for removal of H.sub.2 S from moderately high temperature (usually 200.degree. C.-550.degree.C.) gas streams comprise a porous, high surface area aluminosilicate support, suitably a zeolite, and most preferably a sodium deficient zeolite containing 1 to 20 weight percent of binary metal oxides. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O contained in the support. The sorbent effectively removes H.sub.2 S from the host gas stream in high efficiency and can be repetitively regenerated at least 10 times without loss of activity.

Molecular Dynamics Simulations for Loading-Dependent Diffusion of CO2, SO2, CH4, and Their Binary Mixtures in ZIF-10: The Role of Hydrogen Bond.

PubMed

Li, Li; Yang, Deshuai; Fisher, Trevor R; Qiao, Qi; Yang, Zhen; Hu, Na; Chen, Xiangshu; Huang, Liangliang

2017-10-24

The loading-dependent diffusion behavior of CH 4 , CO 2 , SO 2 , and their binary mixtures in ZIF-10 has been investigated in detail by using classical molecular dynamics simulations. Our simulation results demonstrate that the self-diffusion coefficient D i of CH 4 molecules decreases sharply and monotonically with the loading while those of both CO 2 and SO 2 molecules initially display a slight increase at low uptakes and follow a slow decrease at high uptakes. Accordingly, the interaction energies between CH 4 molecules and ZIF-10 remain nearly constant regardless of the loading due to the absence of hydrogen bonds (HBs), while the interaction energies between CO 2 (or SO 2 ) and ZIF-10 decease rapidly with the loading, especially at small amounts of gas molecules. Such different loading-dependent diffusion and interaction mechanisms can be attributed to the relevant HB behavior between gas molecules and ZIF-10. At low loadings, both the number and strength of HBs between CO 2 (or SO 2 ) molecules and ZIF-10 decrease obviously as the loading increases, which is responsible for the slight increase of their diffusion coefficients. However, at high loadings, their HB strength increases with the loading. Similar loading-dependent phenomena of diffusion, interaction, and HB behavior can be observed for CH 4, CO 2 , and SO 2 binary mixtures in ZIF-10, only associated with some HB competition between CO 2 and SO 2 molecules in the case of the CO 2 /SO 2 mixture.

From the speed of sound to the speed of light: Ultrasonic Cherenkov refractometry

NASA Astrophysics Data System (ADS)

Hallewell, G. D.

2017-12-01

Despite its success in the SLD CRID at the SLAC Linear Collider, ultrasonic measurement of Cherenkov radiator refractive index has been less fully exploited in more recent Cherenkov detectors employing gaseous radiators. This is surprising, since it is ideally suited to monitoring hydrostatic variations in refractive index as well as its evolution during the replacement of a light radiator passivation gas (e.g. N2, CO2) with a heavier fluorocarbon (e.g. C4F10[CF4]; mol. wt. 188[88]). The technique exploits the dependence of sound velocity on the molar concentrations of the two components at known temperature and pressure. The SLD barrel CRID used an 87%C5F12/13%N2 blend, mixed before injection into the radiator vessel: blend control based on ultrasonic mixture analysis maintained the β=1 Cherenkov ring angle to a long term variation better than ±0.3%, with refractivity monitored ultrasonically at multiple points within the radiator vessel. Recent advances using microcontroller-based electronics have led to ultrasonic instruments capable of simultaneously measuring gas flow and binary mixture composition in the fluorocarbon evaporative cooling systems of the ATLAS Inner Detector. Sound transit times are measured with multi-MHz transit time clocks in opposite directions in flowing gas for simultaneous measurement of flow rate and sound velocity. Gas composition is evaluated in real-time by comparison with a sound velocity/composition database. Such instruments could be incorporated into new and upgraded gas Cherenkov detectors for radiator gas mixture (and corresponding refractive index) measurement to a precision better than 10-3. They have other applications in binary gas analysis - including in Xenon-based anaesthesia. These possibilities are discussed.

Isotope Separation in Concurrent Gas Centrifuges

NASA Astrophysics Data System (ADS)

Bogovalov, S. V.; Borman, V. D.

An analytical equation defining separative power of an optimized concurrent gas centrifuge is obtained for an arbitrary binary mixture of isotopes. In the case of the uranium isotopes the equation gives δU= 12.7(V/700 m/s)2(300 K/T)L, kg SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge, T is the temperature. This formula well agrees with an empirical separative power of counter current gas centrifuges.

A Fast and Easily-Realized Concentration Sensor for Binary Gas Mixtures and Its Design Analysis.

PubMed

Guan, Yu; Lu, Song; Zhang, Dan; Hu, Yang; Yuan, Wei

2018-04-19

A low-cost and easily-realized sensing device used for the detection of gas mixtures at different concentrations is presented. Its sensing part includes a small critical nozzle, a laminar structure, and a differential pressure sensor. When gas flows through the laminar structure, there is a pressure drop between both ends of it, and for different components of gas, the pressure drop is different. Based on this feature, the concentration detection is achieved. Concentration tests for two types of fire extinguishing agents CBrF₃ and C₃HF₇ are presented. The results show the characteristics of fast response/recovery time, high accuracy, and good repeatability. Based on the theoretical analysis, the effects of the design parameters on the sensing performance to concentration detection are discussed in detail.

Analysis of consecutively sampled headspace and liquid fractions by gas chromatography/mass spectrometry.

PubMed

Treble, Ronald G; Johnson, Keith E; Xiao, Li; Thompson, Thomas S

2002-07-01

An existing gas chromatograph/mass spectrometer (GC/MS) can be used to analyze gas and liquid fractions from the same system within a few minutes. The technique was applied to (a) separate and identify the gaseous components of the products of cracking an alkane, (b) measure trace levels of acetone in ethyl acetate, (c) determine the relative partial pressures over a binary mixture, and (d) identify nine unknown compounds for the purpose of disposal.

Measurement of viscosity of gaseous mixtures at atmospheric pressure

NASA Technical Reports Server (NTRS)

Singh, J. J.; Mall, G. H.; Chegini, H.

1986-01-01

Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model.

Gas-liquid chromatography with a volatile "stationary" liquid phase.

PubMed

Wells, P S; Zhou, S; Parcher, J F

2002-05-01

A unique type of gas-liquid chromatography is described in which both mobile and "stationary" phases are composed of synthetic mixtures of helium and carbon dioxide. At temperatures below the critical point of the binary mixture and pressures above the vapor pressure of pure liquid carbon dioxide, helium and carbon dioxide can form two immiscible phases over extended composition ranges. A binary vapor phase enriched in helium can act as the mobile phase for chromatographic separations, whereas a CO2-rich liquid in equilibrium with the vapor phase, but condensed on the column wall, can act as a pseudostationary phase. Several examples of chromatographic separations obtained in "empty" capillary columns with no ordinary stationary liquid phase illustrate the range of conditions that produce such separations. In addition, several experiments are reported that confirm the proposed two-phase hypothesis. The possible consequences of the observed chromatographic phenomenon in the field of supercritical fluid chromatography with helium headspace carbon dioxide are discussed.

Solubility Limits in Lennard-Jones Mixtures: Effects of Disparate Molecule Geometries.

PubMed

Dyer, Kippi M; Perkyns, John S; Pettitt, B Montgomery

2015-07-23

In order to better understand general effects of the size and energy disparities between macromolecules and solvent molecules in solution, especially for macromolecular constructs self-assembled from smaller molecules, we use the first- and second-order exact bridge diagram extensions of the HNC integral equation theory to investigate single-component, binary, ternary, and quaternary mixtures of Lennard-Jones fluids. For pure fluids, we find that the HNCH3 bridge function integral equation (i.e., exact to third order in density) is necessary to quantitatively predict the pure gas and pure liquid sides of the coexistence region of the phase diagram of the Lennard-Jones fluid. For the mixtures, we find that the HNCH2 bridge function integral equation is sufficient to qualitatively predict solubility in the binary, ternary, and quaternary mixtures, up to the nominal solubility limit. The results, as limiting cases, should be useful to several problems, including accurate phase diagram predictions for complex mixtures, design of self-assembling nanostructures via solvent controls, and the solvent contributions to the conformational behavior of macromolecules in complex fluids.

Binary Mixture of Perfect Fluid and Dark Energy in Modified Theory of Gravity

NASA Astrophysics Data System (ADS)

Shaikh, A. Y.

2016-07-01

A self consistent system of Plane Symmetric gravitational field and a binary mixture of perfect fluid and dark energy in a modified theory of gravity are considered. The gravitational field plays crucial role in the formation of soliton-like solutions, i.e., solutions with limited total energy, spin, and charge. The perfect fluid is taken to be the one obeying the usual equation of state, i.e., p = γρ with γ∈ [0, 1] whereas, the dark energy is considered to be either the quintessence like equation of state or Chaplygin gas. The exact solutions to the corresponding field equations are obtained for power-law and exponential volumetric expansion. The geometrical and physical parameters for both the models are studied.

Binary gas mixture adsorption-induced deformation of microporous carbons by Monte Carlo simulation.

PubMed

Cornette, Valeria; de Oliveira, J C Alexandre; Yelpo, Víctor; Azevedo, Diana; López, Raúl H

2018-07-15

Considering the thermodynamic grand potential for more than one adsorbate in an isothermal system, we generalize the model of adsorption-induced deformation of microporous carbons developed by Kowalczyk et al. [1]. We report a comprehensive study of the effects of adsorption-induced deformation of carbonaceous amorphous porous materials due to adsorption of carbon dioxide, methane and their mixtures. The adsorption process is simulated by using the Grand Canonical Monte Carlo (GCMC) method and the calculations are then used to analyze experimental isotherms for the pure gases and mixtures with different molar fraction in the gas phase. The pore size distribution determined from an experimental isotherm is used for predicting the adsorption-induced deformation of both pure gases and their mixtures. The volumetric strain (ε) predictions from the GCMC method are compared against relevant experiments with good agreement found in the cases of pure gases. Copyright © 2018 Elsevier Inc. All rights reserved.

Experimental study of the density of the helium-nitrogen gas system at low temperatures.

NASA Astrophysics Data System (ADS)

Milyutin, V. A.

2017-11-01

At the Department of TOT, an experimental setup was created to measure the density of a binary gas system from 100 to 300 K and pressures up to 16 MPa and with any mixture compositions. Experimental density for the helium-nitrogen system were determined by the piezometer of constant volume method. The amount of substance in the piezometer was measured by volumetric method. In this setup, the mixture of He - N2 was prepared in a special mixer for a series of p-v-T experiments, the concentration was determined by calculation using the equations of state of pure components. In the experiment, mixtures were prepared with molar concentrations, lying close to the range: 0.2, 0.4, 0.6 and 0.8.

Assessment of a Novel Ternary Eutectic Chloride Salt for Next Generation High-Temperature Sensible Heat Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vidal, Judith C; Mohan, Gowtham; Venkataraman, Mahesh

A novel ternary eutectic salt mixture for high-temperature sensible heat storage, composed of sodium chloride, potassium chloride and magnesium chloride (NaKMg-Cl) was developed based on a phase diagram generated with FactSage(R). The differential scanning calorimetry (DSC) technique was used to experimentally validate the predicted melting point of the ternary eutectic composition, which was measured as 387 degrees C, in good agreement with the prediction. The ternary eutectic was compared to two binary salts formulated based on prediction of the eutectic composition by FactSage, but unfortunately DSC measurements showed that neither binary salt composition was eutectic. Nonetheless, the measured thermo-physical propertiesmore » of the ternary and the two binary mixtures are compared. Liquid heat capacities of both the ternary and binary salts were determined by using DSC with sapphire as the standard reference. The average heat capacity of the ternary mixture was recorded as 1.18 J g-1 K-1. The mass loss of the molten eutectic salts was studied up to 1000 degrees C using a thermogravimetric analyser in nitrogen, argon and air. The results showed a significant mass loss due to vaporisation in an open system, particularly above 700 degrees C. However, simulation of mass loss in a closed system with an inert cover gas indicates storage temperatures above 700 degrees C may be feasible, and highlights the importance of the design of the storage tank system. In terms of storage material cost, the NaKMg-Cl mixture is approximately 4.5 USD/kWh, which is 60% cheaper than current state-of-the-art nitrate salt mixtures.« less

Excited-state proton transfer dynamics of firefly's chromophore D-luciferin in DMSO-water binary mixture.

PubMed

Kuchlyan, Jagannath; Banik, Debasis; Roy, Arpita; Kundu, Niloy; Sarkar, Nilmoni

2014-12-04

In this article we have investigated intermolecular excited-state proton transfer (ESPT) of firefly's chromophore D-luciferin in DMSO-water binary mixtures using steady-state and time-resolved fluorescence spectroscopy. The unusual behavior of DMSO-water binary mixture as reported by Bagchi et al. (J. Phys. Chem. B 2010, 114, 12875-12882) was also found using D-luciferin as intermolecular ESPT probe. The binary mixture has given evidence of its anomalous nature at low mole fractions of DMSO (below XD = 0.4) in our systematic investigation. Upon excitation of neutral D-luciferin molecule, dual fluorescence emissions (protonated and deprotonated form) are observed in DMSO-water binary mixture. A clear isoemissive point in the time-resolved area normalized emission spectra further indicates two emissive species in the excited state of D-luciferin in DMSO-water binary mixture. DMSO-water binary mixtures of different compositions are fascinating hydrogen bonding systems. Therefore, we have observed unusual changes in the fluorescence emission intensity, fluorescence quantum yield, and fluorescence lifetime of more hydrogen bonding sensitive anionic form of D-luciferin in low DMSO content of DMSO-water binary mixture.

Light scattering in gas mixtures - Evidence of fast and slow sound modes

NASA Astrophysics Data System (ADS)

Clouter, M. J.; Luo, H.; Kiefte, H.; Zollweg, J. A.

1990-02-01

Campa and Cohen (1989) have predicted that dilute, binary mixtures of gases with disparate masses should exhibit a (fast) sound mode whose velocity is considerably greater than expected on the basis of conventional hydrodynamic theory, and which should be observable via light-scattering experiments. Effects that are consistent with this prediction were observed in the Brillouin spectra of the H2 + Ar system, but were not detected for the case of CH4 + SF6. Results for the SF6 + H2 mixture demonstrate the existence of an analogous slow-mode contribution to the spectrum.

Phase-coexisting patterns, horizontal segregation, and controlled convection in vertically vibrated binary granular mixtures

NASA Astrophysics Data System (ADS)

Ansari, Istafaul Haque; Rivas, Nicolas; Alam, Meheboob

2018-01-01

We report patterns consisting of coexistence of synchronous and asynchronous states [for example, a granular gas co-existing with (i) bouncing bed, (ii) undulatory subharmonic waves, and (iii) Leidenfrost-like states] in experiments on vertically vibrated binary granular mixtures in a Hele-Shaw cell. Most experiments have been carried out with equimolar binary mixtures of glass and steel balls of same diameter by varying the total layer height (F ) for a range of shaking acceleration (Γ ). All patterns as well as the related phase diagram in the (Γ ,F ) plane have been reproduced via molecular dynamics simulations of the same system. The segregation of heavier and lighter particles along the horizontal direction is shown to be the progenitor of such phase-coexisting patterns as confirmed in both experiment and simulation. At strong shaking we uncover a partial convection state in which a pair of convection rolls is found to coexist with a Leidenfrost-like state. The crucial role of the relative number density of two species on controlling the buoyancy-driven granular convection is demonstrated. The onset of horizontal segregation can be explained in terms of an anisotropic diffusion tensor.

International comparison CCQM-K111—propane in nitrogen

NASA Astrophysics Data System (ADS)

van der Veen, Adriaan M. H.; Wouter van der Hout, J.; Ziel, Paul R.; Oudwater, Rutger J.; Fioravante, Andreia L.; Augusto, Cristiane R.; Coutinho Brum, Mariana; Uehara, Shinji; Akima, Dai; Bae, Hyun Kil; Kang, Namgoo; Woo, Jin-Chun; Liaskos, Christina E.; Rhoderick, George C.; Jozela, Mudalo; Tshilongo, James; Ntsasa, Napo G.; Botha, Angelique; Brewer, Paul J.; Brown, Andrew S.; Bartlett, Sam; Downey, Michael L.; Konopelko, L. A.; Kolobova, A. V.; Pankov, A. A.; Orshanskaya, A. A.; Efremova, O. V.

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capabilities to prepare primary standard gas Mixtures (PSMs), perform the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this key comparison is classified as a track A key comparison, which means that the results of this key comparison can be used to underpin calibration and measurement capabilities using the flexible scheme, and for propane under the default scheme. The artefacts were binary mixtures of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The results are generally good. All results but one are within +/- 0.2 % of the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

International comparison CCQM-K111.1—propane in nitrogen

NASA Astrophysics Data System (ADS)

van der Veen, Adriaan M. H.; Wouter van der Hout, J.; Ziel, Paul R.; Jozela, Mudalo; Tshilongo, James; Ntsasa, Napo G.; Botha, Angelique

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capability of preparing Primary Standard gas Mixtures (PSMs), performing the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this subsequent key comparison is classified as a track B key comparison, which means that the results of this key comparison can be used to underpin calibration and measurement capabilities for propane under the default scheme. The artefact was a binary mixture of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The result of the participating laboratory is consistent with the key comparison reference value within the respective expanded uncertainties and deviates less than 0.1 %. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Stabilizing the hexagonal close packed structure of hard spheres with polymers: Phase diagram, structure, and dynamics

NASA Astrophysics Data System (ADS)

Edison, John R.; Dasgupta, Tonnishtha; Dijkstra, Marjolein

2016-08-01

We study the phase behaviour of a binary mixture of colloidal hard spheres and freely jointed chains of beads using Monte Carlo simulations. Recently Panagiotopoulos and co-workers predicted [Nat. Commun. 5, 4472 (2014)] that the hexagonal close packed (HCP) structure of hard spheres can be stabilized in such a mixture due to the interplay between polymer and the void structure in the crystal phase. Their predictions were based on estimates of the free-energy penalty for adding a single hard polymer chain in the HCP and the competing face centered cubic (FCC) phase. Here we calculate the phase diagram using free-energy calculations of the full binary mixture and find a broad fluid-solid coexistence region and a metastable gas-liquid coexistence region. For the colloid-monomer size ratio considered in this work, we find that the HCP phase is only stable in a small window at relatively high polymer reservoir packing fractions, where the coexisting HCP phase is nearly close packed. Additionally we investigate the structure and dynamic behaviour of these mixtures.

Pyrolysis of polyethylene mixed with paper and wood: Interaction effects on tar, char and gas yields.

PubMed

Grieco, E M; Baldi, G

2012-05-01

In the present study the interactions between the main constituents of the refuse derived fuel (plastics, paper, and wood) during pyrolysis were studied. Binary mixtures of polyethylene-paper and polyethylene/sawdust have been transformed into pellets and pyrolyzed. Various mixtures with different composition were analyzed and pyrolysis products (tar, gas, and char) were collected. The mixtures of wood/PE and paper/PE have a different behavior. The wood/PE mixtures showed a much reduced interaction of the various compounds because the yields of pyrolysis products of the mixture can be predicted as linear combination of those of the pure components. On the contrary, a strong char yield increase was found at a low heating rate for paper/PE mixtures. In order to explain the results, the ability of wood and paper char to adsorb and convert the products of PE pyrolysis into was studied. Adsorption and desorption tests were performed on the char obtained by paper and wood by using n-hexadecane as a model compound for the heavy products of PE pyrolysis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons: effects of edge-functionalization.

PubMed

Lu, Xiaoqing; Jin, Dongliang; Wei, Shuxian; Zhang, Mingmin; Zhu, Qing; Shi, Xiaofan; Deng, Zhigang; Guo, Wenyue; Shen, Wenzhong

2015-01-21

The effect of edge-functionalization on the competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons (NPCs) has been investigated for the first time by combining density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulation. Our results show that edge-functionalization has a more positive effect on the single-component adsorption of CO2 than CH4, therefore significantly enhancing the selectivity of CO2 over CH4, in the order of NH2-NPC > COOH-NPC > OH-NPC > H-NPC > NPC at low pressure. The enhanced adsorption originates essentially from the effects of (1) the conducive environment with a large pore size and an effective accessible surface area, (2) the high electronegativity/electropositivity, (3) the strong adsorption energy, and (4) the large electrostatic contribution, due to the inductive effect/direct interaction of the embedded edge-functionalized groups. The larger difference from these effects results in the higher competitive adsorption advantage of CO2 in the binary CO2-CH4 mixture. Temperature has a negative effect on the gas adsorption, but no obvious influence on the electrostatic contribution on selectivity. With the increase of pressure, the selectivity of CO2 over CH4 first decreases sharply and subsequently flattens out to a constant value. This work highlights the potential of edge-functionalized NPCs in competitive adsorption, capture, and separation for the binary CO2-CH4 mixture, and provides an effective and superior alternative strategy in the design and screening of adsorbent materials for carbon capture and storage.

Evaluation of measurement data from a sensor system for breath control

NASA Astrophysics Data System (ADS)

Seifert, Rolf; Keller, Hubert B.; Conrad, Thorsten; Peter, Jens

2017-03-01

Binary ethanol-H2 gas samples were measured by an innovative mobile sensor system for the alcohol control in the respiratory air. The measurements were performed by a gas sensor operated by cyclic variation of the working temperature at the sensor head. The evaluation of the data, using an updated version of the evaluation procedure ProSens, results in a very good substance identification and concentration determination of the components of the gas mixture. The relative analysis errors were in all cases less than 9%.

Condensation of binary mixtures on horizontal tubes

NASA Astrophysics Data System (ADS)

Büchner, A.; Reif, A.; Rehfeldt, S.; Klein, H.

2017-12-01

The two most common models to describe the condensation of binary mixtures are the equilibrium model by Silver (Trans Inst Chem Eng 25:30-42, 1947) and the film model by Colburn and Drew (Transactions of the American Institute of Chemical Engineers 33:197-215, 1937), which is stated by Webb et al. (Int J Heat Mass Transf 39:3147-3156, 1996) as more accurate. The film model describes the outer heat transfer coefficient by subdividing it into two separate resistances against the heat transfer. The resistance of the liquid condensate film on the tube can be calculated with equations for the condensation of pure substances for the analogous flow pattern and geometry using the property data of the mixture. The resistance in the gas phase can be described by a thermodynamic parameter Z and the single phase heat transfer coefficient α G . In this work measurements for condensation of the binary mixtures n-pentane/iso-octane and iso-propanol/water on horizontal tubes for free convection are carried out. The obtained results are compared with the film model by Colburn and Drew (Transactions of the American Institute of Chemical Engineers 33:197-215, 1937). The comparison shows a rather big deviation between the theoretical model and the experimental results. To improve the prediction quality an own model based on dimensionless numbers is proposed, which describes the experimental results of this work significantly better than the film model.

Emulsifier of Arthrobacter RAG-1: specificity of hydrocarbon substrate.

PubMed Central

Rosenberg, E; Perry, A; Gibson, D T; Gutnick, D L

1979-01-01

The purified extracellular emulsifying factor produced by Arthrobacter RAG-1 (EF-RAG) emulsified light petroleum oil, diesel oil, and a variety of crude oils and gas oils. Although kerosine and gasoline were emulsified poorly by EF-RAG, they were converted into good substrates for emulsification by addition of aromatic compounds, such as 2-methylnaphthalene. Neither aromatic nor aliphatic fractions of crude oil were emulsified by EF-RAG; however, mixtures containing both fractions were emulsified. Pure aliphatic or aromatic hydrocarbons were emulsified poorly by EF-RAG. Binary mixtures containing an aliphatic and an aromatic hydrocarbon, however, were excellent substrates for EF-RAG-induced emulsification. Of a variety of alkylcyclohexane and alkylbenzene derivatives tested, only hexyl- or heptylbenzene and octyl- or decylcyclohexane were effectively emulsified by EF-RAG. These data indicate that for EF-RAG to induce emulsification of hydrocarbons in water, the hydrocarbon substrate must contain both aliphatic and cyclic components. With binary mixtures of methylnaphthalene and hexadecane, maximum emulsion was obtained with 25% hexadecane. PMID:453821

Viscosities of nonelectrolyte liquid mixtures. III. Selected binary and quaternary mixtures

NASA Astrophysics Data System (ADS)

Wakefield, D. L.

1988-05-01

This paper is the final in a series of three viscosity and density studies of pure n-alkanes and selected binary and quaternary mixtures. A standard U-tube viscometer was used for viscosity measurements, and a Pyrex flask-type pycnometer was used for density determinations. Results are given here for pure alkane and selected binary mixtures of n-tetradecane + n-octane, for selected quaternary mixtures of n-hexadecane + n-dodecane + n-decane + n-hexane, and for pure and selected quaternary mixtures of n-hexadecane + n-dodecane + n-nonane + n-heptane at 303.16 and 308.16 K. The principle of congruence was tested, as was the Grunberg and Nissan equation, as they have been shown to be useful as prediction techniques for other n-alkane binary mixtures. Comparisons were made between the two groups of quaternary alkane mixtures and the binary n-tetradecane + n-octane mixtures of the same “pseudo” composition to understand better the dependence of mixture viscosities on the composition parameter.

Acoustic composition sensor for cryogenic gas mixtures

NASA Technical Reports Server (NTRS)

Shakkottai, P.; Kwack, E. Y.; Luchik, T. S.; Back, L. H.

1991-01-01

An acoustic sensor useful for the determination of the composition of a gaseous binary mixture in cryogenic liquid spills has been characterized. One version of the instrument traps a known mixture of helium and nitrogen at ambient temperature in a tube which is interrogated by sonic pulses to determine the speed of sound and hence the composition. Experimental data shows that this sensor is quite accurate. The second version uses two unconfined microphones which sense sound pulses. Experimental data acquired during mixing when liquid nitrogen is poured into a vessel of gaseous helium is presented. Data during transient cooling of the tubular sensor containing nitrogen when the sensor is dipped into liquid nitrogen and during transient warm-up when the sensor is withdrawn are also presented. This sensor is being developed for use in the mixing of liquid cryogens with gas evolution in the simulation of liquid hydrogen/liquid oxygen explosion hazards.

Acoustic composition sensor for cryogenic gas mixtures

NASA Astrophysics Data System (ADS)

Shakkottai, P.; Kwack, E. Y.; Luchik, T. S.; Back, L. H.

An acoustic sensor useful for the determination of the composition of a gaseous binary mixture in cryogenic liquid spills has been characterized. One version of the instrument traps a known mixture of helium and nitrogen at ambient temperature in a tube which is interrogated by sonic pulses to determine the speed of sound and hence the composition. Experimental data shows that this sensor is quite accurate. The second version uses two unconfined microphones which sense sound pulses. Experimental data acquired during mixing when liquid nitrogen is poured into a vessel of gaseous helium is presented. Data during transient cooling of the tubular sensor containing nitrogen when the sensor is dipped into liquid nitrogen and during transient warm-up when the sensor is withdrawn are also presented. This sensor is being developed for use in the mixing of liquid cryogens with gas evolution in the simulation of liquid hydrogen/liquid oxygen explosion hazards.

Influence of protein size on surface-enhanced Raman scattering (SERS) spectra in binary protein mixtures.

PubMed

Avci, Ertug; Culha, Mustafa

2014-01-01

The size-dependent interactions of eight blood proteins with silver nanoparticles (AgNPs) in their binary mixtures were investigated using surface-enhanced Raman scattering (SERS). Principal component analysis (PCA) was performed on the SERS spectra of each binary mixture, and the differentiation ability of the mixtures was tested. It was found that the effect of relative concentration change on the SERS spectra of the binary mixtures of small proteins could be detected using PCA. However, this change was not observed with the binary mixtures of large proteins. This study demonstrated that the relative interactions of the smaller proteins with an average size of 50 nm AgNPs smaller than the large proteins could be monitored, and this information can be used for the detection of proteins in protein mixtures.

Oxidation-chlorination of binary Ni-Cr alloys in flowing Ar-O2-Cl2 gas mixtures at 1200 K

NASA Technical Reports Server (NTRS)

Mcnallan, M. J.; Lee, Y. Y.; Chang, Y. W.; Jacobson, N. S.; Doychak, J.

1991-01-01

Nickel-chromium alloys are resistant to oxidation because of the selective oxidation of chromium to form a protective Cr2O3 scale. In chlorine-containing environments, volatile corrosion products can also be formed. The mixed oxidation-chlorination of Ni-4.5Cr, Ni-13.8Cr, and Ni-26.5Cr (by weight) alloys in Ar-O2-Cl2 gas mixtures is investigated using thermogravimetric analysis and atmospheric-pressure-sampling mass spectrometry, followed by examination of the corrosion products using scanning electron microscopy and X-ray diffraction analysis. The overall kinetics of the corrosion are affected by the relative amounts of oxides and chlorides formed and the composition of the oxide corrosion products.

Low temperature binary gas mixtures

NASA Astrophysics Data System (ADS)

McIntosh, Glen E.; Leonard, Kenneth R.

2017-12-01

Application of partial pressure technology to combinations of one gas above its critical temperature (helium) mixed with a two-phase liquid (nitrogen) can result in liquid temperatures down to and below the nitrogen triple point. The thermodynamics of this process is developed and an experimental apparatus is described which was used to produce a helium/nitrogen bath temperature of 59.17 K, 4 K lower than the 63.2 K nitrogen triple point and lower than any liquid nitrogen temperature reported in the literature.

ThermoData Engine Database - Pure Compounds and Binary Mixtures

National Institute of Standards and Technology Data Gateway

SRD 103b NIST ThermoData Engine Version 6.0 - Pure CompoThermoData Engine Database - Pure Compounds and Binary Mixtures (PC database for purchase)   This database contains property data for more than 21,000 pure compounds, 37,500 binary mixtures, 10,000 ternary mixtures, and 6,000 chemical reactions.

Mathematics of thermal diffusion in an exponential temperature field

NASA Astrophysics Data System (ADS)

Zhang, Yaqi; Bai, Wenyu; Diebold, Gerald J.

2018-04-01

The Ludwig-Soret effect, also known as thermal diffusion, refers to the separation of gas, liquid, or solid mixtures in a temperature gradient. The motion of the components of the mixture is governed by a nonlinear, partial differential equation for the density fractions. Here solutions to the nonlinear differential equation for a binary mixture are discussed for an externally imposed, exponential temperature field. The equation of motion for the separation without the effects of mass diffusion is reduced to a Hamiltonian pair from which spatial distributions of the components of the mixture are found. Analytical calculations with boundary effects included show shock formation. The results of numerical calculations of the equation of motion that include both thermal and mass diffusion are given.

Assessment and prediction of joint algal toxicity of binary mixtures of graphene and ionic liquids.

PubMed

Wang, Zhuang; Zhang, Fan; Wang, Se; Peijnenburg, Willie J G M

2017-10-01

Graphene and ionic liquids (ILs) released into the environment will interact with each other. So far however, the risks associated with the concurrent exposure of biota to graphene and ILs in the environment have received little attention. The research reported here focused on observing and predicting the joint toxicity effects in the green alga Scenedesmus obliquus exposed to binary mixtures of intrinsic graphene (iG)/graphene oxide (GO) and five ILs of varying anionic and cationic types. The isolated ILs in the binary mixtures were the main contributors to toxicity. The binary GO-IL mixtures resulted in more severe joint toxicity than the binary iG-IL mixtures, irrespective of mixture ratios. The mechanism of the joint toxicity may be associated with the adsorption capability of the graphenes for the ILs, the dispersion stability of the graphenes in aquatic media, and modulation of the binary mixtures-induced oxidative stress. A toxic unit assessment showed that the graphene and IL toxicities were additive at low concentration of the mixtures but antagonistic at high concentration of the mixtures. Predictions made using the concentration addition and independent action models were close to the observed joint toxicities regardless of mixture types and mixture ratios. These findings provide new insights that are of use in the risk assessment of mixtures of engineered nanoparticles and other environmentally relevant contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transport properties in mixtures involving carbon dioxide at low and moderate density: test of several intermolecular potential energies and comparison with experiment

NASA Astrophysics Data System (ADS)

Moghadasi, Jalil; Yousefi, Fakhri; Papari, Mohammad Mehdi; Faghihi, Mohammad Ali; Mohsenipour, Ali Asghar

2009-09-01

It is the purpose of this paper to extract unlike intermolecular potential energies of five carbon dioxide-based binary gas mixtures including CO2-He, CO2-Ne, CO2-Ar, CO2-Kr, and CO2-Xe from viscosity data and compare the calculated potentials with other models potential energy reported in literature. Then, dilute transport properties consisting of viscosity, diffusion coefficient, thermal diffusion factor, and thermal conductivity of aforementioned mixtures are calculated from the calculated potential energies and compared with literature data. Rather accurate correlations for the viscosity coefficient of afore-cited mixtures embracing the temperature range 200 K < T < 3273.15 K is reproduced from the present unlike intermolecular potentials energy. Our estimated accuracies for the viscosity are to within ±2%. In addition, the calculated potential energies are used to present smooth correlations for other transport properties. The accuracies of the binary diffusion coefficients are of the order of ±3%. Finally, the unlike interaction energy and the calculated low density viscosity have been employed to calculate high density viscosities using Vesovic-Wakeham method.

Dielectric and spectroscopic study of binary mixture of Acrylonitrile with Chlorobenzene

NASA Astrophysics Data System (ADS)

Deshmukh, Snehal D.; Pattebahadur, K. L.; Mohod, A. G.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

2018-05-01

In this paper, study of binary mixture of Acrylonitrile (ACN) with Chlorobenzene (CBZ) has been carried out at eleven concentrations at room temperature. The determined Dielectric Constant (ɛ0) Density (ρ) and Refractive index (nD) values of binary mixture are used to calculate the excess properties of mixture over the entire composition range and fitted to the Redlich-Kister equation. From the above parameters, intermolecular interaction and dynamics of molecules of binary mixture at molecular level are discussed. The Conformational analysis of the intermolecular interaction between Acrylonitrile and Chlorobenzene is supported by the FTIR spectra.

Kinetics of binary nucleation of vapors in size and composition space.

PubMed

Fisenko, Sergey P; Wilemski, Gerald

2004-11-01

We reformulate the kinetic description of binary nucleation in the gas phase using two natural independent variables: the total number of molecules g and the molar composition x of the cluster. The resulting kinetic equation can be viewed as a two-dimensional Fokker-Planck equation describing the simultaneous Brownian motion of the clusters in size and composition space. Explicit expressions for the Brownian diffusion coefficients in cluster size and composition space are obtained. For characterization of binary nucleation in gases three criteria are established. These criteria establish the relative importance of the rate processes in cluster size and composition space for different gas phase conditions and types of liquid mixtures. The equilibrium distribution function of the clusters is determined in terms of the variables g and x. We obtain an approximate analytical solution for the steady-state binary nucleation rate that has the correct limit in the transition to unary nucleation. To further illustrate our description, the nonequilibrium steady-state cluster concentrations are found by numerically solving the reformulated kinetic equation. For the reformulated transient problem, the relaxation or induction time for binary nucleation was calculated using Galerkin's method. This relaxation time is affected by processes in both size and composition space, but the contributions from each process can be separated only approximately.

Thermally modulated nano-trampoline material as smart skin for gas molecular mass detection

NASA Astrophysics Data System (ADS)

Xia, Hua

2012-06-01

Conventional multi-component gas analysis is based either on laser spectroscopy, laser and photoacoustic absorption at specific wavelengths, or on gas chromatography by separating the components of a gas mixture primarily due to boiling point (or vapor pressure) differences. This paper will present a new gas molecular mass detection method based on thermally modulated nano-trampoline material as smart skin for gas molecular mass detection by fiber Bragg grating-based gas sensors. Such a nanomaterial and fiber Bragg grating integrated sensing device has been designed to be operated either at high-energy level (highly thermal strained status) or at low-energy level (low thermal strained status). Thermal energy absorption of gas molecular trigs the sensing device transition from high-thermal-energy status to low-thermal- energy status. Experiment has shown that thermal energy variation due to gas molecular thermal energy absorption is dependent upon the gas molecular mass, and can be detected by fiber Bragg resonant wavelength shift with a linear function from 17 kg/kmol to 32 kg/kmol and a sensitivity of 0.025 kg/kmol for a 5 micron-thick nano-trampoline structure and fiber Bragg grating integrated gas sensing device. The laboratory and field validation data have further demonstrated its fast response characteristics and reliability to be online gas analysis instrument for measuring effective gas molecular mass from single-component gas, binary-component gas mixture, and multi-gas mixture. The potential industrial applications include fouling and surge control for gas charge centrifugal compressor ethylene production, gas purity for hydrogen-cooled generator, gasification for syngas production, gasoline/diesel and natural gas fuel quality monitoring for consumer market.

The Solubility Parameters of Ionic Liquids

PubMed Central

Marciniak, Andrzej

2010-01-01

The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated. PMID:20559495

Critical lines for an unequal size of molecules in a binary gas-liquid mixture around the van Laar point using the combination of the Tompa model and the van der Waals equation.

PubMed

Gençaslan, Mustafa; Keskin, Mustafa

2012-02-14

We combine the modified Tompa model with the van der Waals equation to study critical lines for an unequal size of molecules in a binary gas-liquid mixture around the van Laar point. The van Laar point is coined by Meijer and it is the only point at which the mathematical double point curve is stable. It is the intersection of the tricritical point and the double critical end point. We calculate the critical lines as a function of χ(1) and χ(2), the density of type I molecules and the density of type II molecules for various values of the system parameters; hence the global phase diagrams are presented and discussed in the density-density plane. We also investigate the connectivity of critical lines at the van Laar point and its vicinity and discuss these connections according to the Scott and van Konynenburg classifications. It is also found that the critical lines and phase behavior are extremely sensitive to small modifications in the system parameters. © 2012 American Institute of Physics

Critical Temperature Differences of a Standing Wave Thermoacoustic Prime Mover with Various Helium-Based Binary Mixture Working Gases

NASA Astrophysics Data System (ADS)

Setiawan, Ikhsan; Nohtomi, Makoto; Katsuta, Masafumi

2015-06-01

Thermoacoustic prime movers are energy conversion devices which convert thermal energy into acoustic work. The devices are environmentally friendly because they do not produce any exhaust gases. In addition, they can utilize clean energy such as solar-thermal energy or waste heat from internal combustion engines as the heat sources. The output mechanical work of thermoacoustic prime movers are usually used to drive a thermoacoustic refrigerator or to generate electricity. A thermoacoustic prime mover with low critical temperature difference is desired when we intend to utilize low quality of heat sources such as waste heat and sun light. The critical temperature difference can be significantly influenced by the kinds of working gases inside the resonator and stack's channels of the device. Generally, helium gas is preferred as the working gas due to its high sound speed which together with high mean pressure will yield high acoustic power per unit volume of the device. Moreover, adding a small amount of a heavy gas to helium gas may improve the efficiency of thermoacoustic devices. This paper presents numerical study and estimation of the critical temperature differences of a standing wave thermoacoustic prime mover with various helium-based binary-mixture working gases. It is found that mixing helium (He) gas with other common gases, namely argon (Ar), nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), at appropriate pressures and molar compositions, reduce the critical temperature differences to lower than those of the individual components of the gas mixtures. In addition, the optimum mole fractions of Hegas which give the minimum critical temperature differences are shifted to larger values as the pressure increases, and tends to be constant at around 0.7 when the pressure increases more than 2 MPa. However, the minimum critical temperature differences slightly increase as the pressure increases to higher than 1.5 MPa. Furthermore, we found that the lowest critical temperature difference for He-Armixture gas is around 66 °C which is achieved in pressure range of 1.5 MPa - 2.0 MPa and mole fractions of helium of 0.55 - 0.65. The He-N2 and He-O2 mixture gases demonstrate almost the same performances, both have the lowest critical temperature difference around 59 °C atpressures of 1.0 MPa - 1.5 MPa and helium's mole fractions of 0.35 - 0.55. For all tested gases, the lowest critical temperature difference of around 51 °C is provided by He-CO2 mixture gas at pressures of 0.5 MPa - 1.0 MPa with helium's mole fractions of 0.15 - 0.40.

Custom ultrasonic instrumentation for flow measurement and real-time binary gas analysis in the CERN ATLAS experiment

NASA Astrophysics Data System (ADS)

Alhroob, M.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Boyd, G.; Crespo-Lopez, O.; Degeorge, C.; Deterre, C.; Di Girolamo, B.; Doubek, M.; Favre, G.; Hallewell, G.; Katunin, S.; Lombard, D.; Madsen, A.; McMahon, S.; Nagai, K.; O'Rourke, A.; Pearson, B.; Robinson, D.; Rossi, C.; Rozanov, A.; Stanecka, E.; Strauss, M.; Vacek, V.; Vaglio, R.; Young, J.; Zwalinski, L.

2017-01-01

The development of custom ultrasonic instrumentation was motivated by the need for continuous real-time monitoring of possible leaks and mass flow measurement in the evaporative cooling systems of the ATLAS silicon trackers. The instruments use pairs of ultrasonic transducers transmitting sound bursts and measuring transit times in opposite directions. The gas flow rate is calculated from the difference in transit times, while the sound velocity is deduced from their average. The gas composition is then evaluated by comparison with a molar composition vs. sound velocity database, based on the direct dependence between sound velocity and component molar concentration in a gas mixture at a known temperature and pressure. The instrumentation has been developed in several geometries, with five instruments now integrated and in continuous operation within the ATLAS Detector Control System (DCS) and its finite state machine. One instrument monitors C3F8 coolant leaks into the Pixel detector N2 envelope with a molar resolution better than 2ṡ 10-5, and has indicated a level of 0.14 % when all the cooling loops of the recently re-installed Pixel detector are operational. Another instrument monitors air ingress into the C3F8 condenser of the new C3F8 thermosiphon coolant recirculator, with sub-percent precision. The recent effect of the introduction of a small quantity of N2 volume into the 9.5 m3 total volume of the thermosiphon system was clearly seen with this instrument. Custom microcontroller-based readout has been developed for the instruments, allowing readout into the ATLAS DCS via Modbus TCP/IP on Ethernet. The instrumentation has many potential applications where continuous binary gas composition is required, including in hydrocarbon and anaesthetic gas mixtures.

Predicting mixture phase equilibria and critical behavior using the SAFT-VRX approach.

PubMed

Sun, Lixin; Zhao, Honggang; Kiselev, Sergei B; McCabe, Clare

2005-05-12

The SAFT-VRX equation of state combines the SAFT-VR equation with a crossover function that smoothly transforms the classical equation into a nonanalytical form close to the critical point. By a combinination of the accuracy of the SAFT-VR approach away from the critical region with the asymptotic scaling behavior seen at the critical point of real fluids, the SAFT-VRX equation can accurately describe the global fluid phase diagram. In previous work, we demonstrated that the SAFT-VRX equation very accurately describes the pvT and phase behavior of both nonassociating and associating pure fluids, with a minimum of fitting to experimental data. Here, we present a generalized SAFT-VRX equation of state for binary mixtures that is found to accurately predict the vapor-liquid equilibrium and pvT behavior of the systems studied. In particular, we examine binary mixtures of n-alkanes and carbon dioxide + n-alkanes. The SAFT-VRX equation accurately describes not only the gas-liquid critical locus for these systems but also the vapor-liquid equilibrium phase diagrams and thermal properties in single-phase regions.

Investigation of intermolecular interaction of binary mixture of acrylonitrile with bromobenzene

NASA Astrophysics Data System (ADS)

Deshmukh, S. D.; Pattebahadur, K. L.; Mohod, A. G.; Patil, S. S.; Khirade, P. W.

2018-04-01

In this paper, study of binary mixture of Acrylonitrile (ACN)with Bromobenzene(BB) has been carried out at eleven concentrations at room temperature. The determined density(ρ) and refractive index (nD) values of binary mixture are used to calculate the excess properties of mixture over the entire composition range. The aforesaid parameters are used to calculate excess parameters and fitted to the Redlich-Kister equation to determine the bj coefficients. From the above parameters, intermolecular interaction and dynamics of molecules of binary mixture at molecular level are discussed. The Conformational analysis of the intermolecular interaction between Acrylonitrile and Bromobenzene is supported by the FTIR spectra.

Recognition by Rats of Binary Taste Solutions and Their Components.

PubMed

Katagawa, Yoshihisa; Yasuo, Toshiaki; Suwabe, Takeshi; Yamamura, Tomoki; Gen, Keika; Sako, Noritaka

2016-09-13

This behavioral study investigated how rats conditioned to binary mixtures of preferred and aversive taste stimuli, respectively, responded to the individual components in a conditioned taste aversion (CTA) paradigm. The preference of stimuli was determined based on the initial results of 2 bottle preference test. The preferred stimuli included 5mM sodium saccharin (Sacc), 0.03M NaCl (Na), 0.1M Na, 5mM Sacc + 0.03M Na, and 5mM Sacc + 0.2mM quinine hydrochloride (Q), whereas the aversive stimuli tested were 1.0M Na, 0.2mM Q, 0.3mM Q, 5mM Sacc + 1.0M Na, and 5mM Sacc + 0.3mM Q. In CTA tests where LiCl was the unconditioned stimulus, the number of licks to the preferred binary mixtures and to all tested preferred components were significantly less than in control rats. No significant difference resulted between the number of licks to the aversive binary mixtures or to all tested aversive components. However, when rats pre-exposed to the aversive components contained of the aversive binary mixtures were conditioned to these mixtures, the number of licks to all the tested stimuli was significantly less than in controls. Rats conditioned to components of the aversive binary mixtures generalized to the binary mixtures containing those components. These results suggest that rats recognize and remember preferred and aversive taste mixtures as well as the preferred and aversive components of the binary mixtures, and that pre-exposure before CTA is an available method to study the recognition of aversive taste stimuli. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dynamic adsorption of CO2/N2 on cation-exchanged chabazite SSZ-13: A breakthrough analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bower, Jamey K.; Barpaga, Dushyant; Prodinger, Sebastian

2018-04-17

Alkali exchanged SSZ-13 adsorbents were investigated for their applicability in separating N2 from CO2 in flue gas streams using a dynamic breakthrough method. In contrast to IAST calculations based on equilibrium isotherms, K+ exchanged SSZ-13 was found to yield the best N2 productivity under dynamic conditions where diffusion properties play a significant role. This was attributed to the selective, partial blockage of access to the CHA cavities enhancing the separation potential in a 15/85 CO2/N2 binary gas mixture.

Dynamic Adsorption of CO 2 /N 2 on Cation-Exchanged Chabazite SSZ-13: A Breakthrough Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bower, Jamey K.; Barpaga, Dushyant; Prodinger, Sebastian

2018-03-30

Alkali exchanged SSZ-13 adsorbents were investigated for their applicability in separating N2 from CO 2 in flue gas streams using a dynamic breakthrough method. In contrast to IAST calculations based on equilibrium isotherms, K+ exchanged SSZ-13 was found to yield the best N2 productivity under dynamic conditions where diffusion properties play a significant role. This was attributed to the selective, partial blockage of access to the CHA cavities enhancing the separation potential in a 15/85 CO2/N2 binary gas mixture.

Development and testing of a numerical simulation method for thermally nonequilibrium dissociating flows in ANSYS Fluent

NASA Astrophysics Data System (ADS)

Shoev, G. V.; Bondar, Ye. A.; Oblapenko, G. P.; Kustova, E. V.

2016-03-01

Various issues of numerical simulation of supersonic gas flows with allowance for thermochemical nonequilibrium on the basis of fluid dynamic equations in the two-temperature approximation are discussed. The computational tool for modeling flows with thermochemical nonequilibrium is the commercial software package ANSYS Fluent with an additional userdefined open-code module. A comparative analysis of results obtained by various models of vibration-dissociation coupling in binary gas mixtures of nitrogen and oxygen is performed. Results of numerical simulations are compared with available experimental data.

Comparison of numerical simulation and experimental data for steam-in-place sterilization

NASA Technical Reports Server (NTRS)

Young, Jack H.; Lasher, William C.

1993-01-01

A complex problem involving convective flow of a binary mixture containing a condensable vapor and noncondensable gas in a partially enclosed chamber was modelled and results compared to transient experimental values. The finite element model successfully predicted transport processes in dead-ended tubes with inside diameters of 0.4 to 1.0 cm. When buoyancy driven convective flow was dominant, temperature and mixture compositions agreed with experimental data. Data from 0.4 cm tubes indicate diffusion to be the primary air removal method in small diameter tubes and the diffusivity value in the model to be too large.

Solubility enhancement of miconazole nitrate: binary and ternary mixture approach.

PubMed

Rai, Vineet Kumar; Dwivedi, Harinath; Yadav, Narayan Prasad; Chanotiya, Chandan Singh; Saraf, Shubhini A

2014-08-01

Enhancement of aqueous solubility of very slightly soluble Miconazole Nitrate (MN) is required to widen its application from topical formulation to oral/mucoadhesive formulations. Aim of the present investigation was to enhance the aqueous solubility of MN using binary and ternary mixture approach. Binary mixtures such as solvent deposition, inclusion complexation and solid dispersion were adopted to enhance solubility using different polymers like lactose, beta-cyclodextrin (β-CD) and polyethylene-glycol 6000 (PEG 6000), respectively. Batches of binary mixtures with highest solubility enhancement potentials were further mixed to form ternary mixture by a simple kneading method. Drug polymer interaction and mixture morphology was studied using the Fourier transform infrared spectroscopy and the scanning electron microscopy, respectively along with their saturation solubility studies and drug release. An excellent solubility enhancement, i.e. up to 72 folds and 316 folds of MN was seen by binary and ternary mixture, respectively. Up to 99.5% drug was released in 2 h from the mixtures of MN and polymers. RESULTS revealed that solubility enhancement by binary mixtures is achieved due to surface modification and by increasing wettability of MN. Tremendous increase in solubility of MN by ternary mixture could possibly be due to blending of water soluble polymers, i.e. lactose and PEG 6000 with β-CD which was found to enhance the solubilizing nature of β-CD. Owing to the excellent solubility enhancement potential of ternary mixtures in enhancing MN solubility from 110.4 μg/ml to 57640.0 μg/ml, ternary mixture approach could prove to be promising in the development of oral/mucoadhesive formulations.

Asymptotic modeling of flows of a mixture of two monoatomic gases in a coplanar microchannel

NASA Astrophysics Data System (ADS)

Gatignol, Renée; Croizet, Cédric

2016-11-01

Gas mixtures are present in a number of microsystems, such as heat exchangers, propulsion systems, and so on. This paper aims to describe some basic physical phenomena of flows of a mixture of two monoatomic gases in a coplanar microchannel. Gas flows are described by the Navier-Stokes-Fourier equations with coupling terms, and with first order boundary conditions for the velocities and the temperatures on the microchannel walls. With the small parameter equal to the ratio of the transverse and longitudinal lengths, an asymptotic model was presented at the 29th Symposium on Rarefied Gas Dynamics. It corresponds to a low Mach number and a low to moderate Knudsen number. First-order differential equations for mass, momentum and energy have been written. For each species, the pressure depends only on the longitudinal variable and the temperature is equal to the wall temperature (the two walls have the same temperature). Both pressures are solutions of ordinary differential equations. Results are given on the longitudinal profile of both pressures and on the longitudinal velocities, for different binary mixtures, and for the cases of isothermal and thermal regimes. Asymptotic solutions are compared to DSMC simulations in the same configuration: they are roughly in agreement.

Solidification phenomena of binary organic mixtures

NASA Technical Reports Server (NTRS)

Chang, K.

1982-01-01

The coalescence rates and motion of liquid bubbles in binary organic mixtures were studied. Several factors such as temperature gradient, composition gradient, interfacial tension, and densities of the two phases play important roles in separation of phases of immiscible liquids. An attempt was made to study the effect of initial compositions on separation rates of well-dispersed organic mixtures at different temperatures and, ultimately, on the homogeneity of solidification of the immiscible binary organic liquids. These organic mixtures serve as models for metallic pseudo binary systems under study. Two specific systems were investigated: ethyl salicylate - diethyl glycol and succinonitrile - water.

Phase behaviour of the symmetric binary mixture from thermodynamic perturbation theory.

PubMed

Dorsaz, N; Foffi, G

2010-03-17

We study the phase behaviour of symmetric binary mixtures of hard core Yukawa (HCY) particles via thermodynamic perturbation theory (TPT). We show that all the topologies of phase diagram reported for the symmetric binary mixtures are correctly reproduced within the TPT approach. In a second step we use the capability of TPT to be straightforwardly extended to mixtures that are nonsymmetric in size. Starting from mixtures that belong to the different topologies of symmetric binary mixtures we investigate the effect on the phase behaviour when an asymmetry in the diameters of the two components is introduced. Interestingly, when the energy of interaction between unlike particles is weaker than the interaction between like particles, the propensity for the solution to demix is found to increase strongly with size asymmetry.

A deeper insight into an intriguing acetonitrile-water binary mixture: synergistic effect, dynamic Stokes shift, fluorescence correlation spectroscopy, and NMR studies.

PubMed

Koley, Somnath; Ghosh, Subhadip

2016-11-30

An insight study reveals the strong synergistic solvation behaviours from reporter dye molecules within the acetonitrile (ACN)-water (WT) binary mixture. Synergism of a binary mixture refers to some unique changes of the physical and thermodynamic properties of the solvent mixture, originating from the interactions among its cosolvents, which are absent within the pure cosolvents. Synergistic solvation of a binary mixture is likely to be fundamental for greater stabilization of an excited state solute dipole; at least to some extent greater as compared to one stabilized by any of its cosolvents alone. A dynamic Stokes shift due to the solvation of an excited dipole in the ACN-WT binary mixture is found to be highly relevant to the ground state physical properties of the solute molecule (polarity, hydrophilicity, acidity, etc.). Largely different solvation times in the ACN-WT mixture are observed from different dye molecules with widely varying polarities. However, earlier study shows that dye molecules, irrespective of their varying polarities, exhibit very similar solvation times within a pure solvent (J. Phys. Chem. B, 2014, 118, 7577-7785). On further study with fluorescence correlation spectroscopy (FCS) we observed that, unlike the translational diffusion coefficient (D t ) of a dye molecule within a pure solvent, which remains the same irrespective of the location of the dye molecule inside the solvent, a broad distribution among the D t values of a dye molecule is obtained from different locations within the ACN-WT binary mixture. Lastly our 1 H NMR study in the ACN-WT binary mixture shows the existence of strong hydrogen bond interactions among the cosolvents in the ACN-WT mixture.

Sedimentation of a two-dimensional colloidal mixture exhibiting liquid-liquid and gas-liquid phase separation: a dynamical density functional theory study.

PubMed

Malijevský, Alexandr; Archer, Andrew J

2013-10-14

We present dynamical density functional theory results for the time evolution of the density distribution of a sedimenting model two-dimensional binary mixture of colloids. The interplay between the bulk phase behaviour of the mixture, its interfacial properties at the confining walls, and the gravitational field gives rise to a rich variety of equilibrium and non-equilibrium morphologies. In the fluid state, the system exhibits both liquid-liquid and gas-liquid phase separation. As the system sediments, the phase separation significantly affects the dynamics and we explore situations where the final state is a coexistence of up to three different phases. Solving the dynamical equations in two-dimensions, we find that in certain situations the final density profiles of the two species have a symmetry that is different from that of the external potentials, which is perhaps surprising, given the statistical mechanics origin of the theory. The paper concludes with a discussion on this.

Bactericidal action of binary and ternary mixtures of carvacrol, thymol, and eugenol against Listeria innocua.

PubMed

García-García, Rebeca; López-Malo, Aurelio; Palou, Enrique

2011-03-01

The bactericidal effect of 3 natural agents (carvacrol, thymol, and eugenol) was evaluated as well as their binary and ternary mixtures on Listeria innocua inactivation in liquid model systems. Minimal bactericidal concentrations (MBC) of these agents were determined, and then binary and ternary mixtures were evaluated. Culture media were inoculated with L. innocua and incubated for 72 h at 35 °C. Turbidity of studied systems were determined every 24 h. The most effective individual antimicrobial agent was carvacrol, followed by thymol and then eugenol with MBCs of 150, 250, and 450 mg kg(-1), respectively. It was observed that the most effective binary mixture was 75 mg kg(-1) carvacrol and 62.5 mg kg(-1) thymol. Furthermore, the ternary mixture carvacrol-thymol-eugenol in concentrations of 75, 31.25, and 56.25 mg kg(-1), correspondingly, was the most effective for L. innocua inactivation. Several binary and ternary mixtures of these 3 natural antimicrobial agents worked adequately to inactivate L. innocua.

Experimental study on thermal storage performance of binary mixtures of fatty acids

NASA Astrophysics Data System (ADS)

Yan, Quanying; Zhang, Jing; Liu, Chao; Liu, Sha; Sun, Xiangyu

2018-02-01

We selected five kinds of fatty acids including the capric acid, stearic acid, lauric acid, palmitic acid and myristic acid and mixed them to prepare10 kinds of binary mixtures of fatty acids according to the predetermined proportion,tested the phase change temperature and latent heat of mixtures by differential scanning calorimetry(DSC). In order to find the fatty acid mixture which has suitable phase change temperature, the larger phase change latent heat and can be used for phase change wall. The results showed that the phase change temperature and latent heats of the binary mixtures of fatty acids decreased compared with the single component;The phase change temperature of the binary mixtures of fatty acids containing capric acid were lower, the range was roughly 20∼30°C,and latent heat is large,which are ideal phase change materials for phase change wall energy storage;The phase change temperature of the binary mixtures consisting of other fatty acids were still high,didn’t meet the temperature requirements of the wall energy storage.

The Precise Measurement of Vapor-Liquid Equilibrium Properties of the CO2/Isopentane Binary Mixture, and Fitted Parameters for a Helmholtz Energy Mixture Model

NASA Astrophysics Data System (ADS)

Miyamoto, H.; Shoji, Y.; Akasaka, R.; Lemmon, E. W.

2017-10-01

Natural working fluid mixtures, including combinations of CO2, hydrocarbons, water, and ammonia, are expected to have applications in energy conversion processes such as heat pumps and organic Rankine cycles. However, the available literature data, much of which were published between 1975 and 1992, do not incorporate the recommendations of the Guide to the Expression of Uncertainty in Measurement. Therefore, new and more reliable thermodynamic property measurements obtained with state-of-the-art technology are required. The goal of the present study was to obtain accurate vapor-liquid equilibrium (VLE) properties for complex mixtures based on two different gases with significant variations in their boiling points. Precise VLE data were measured with a recirculation-type apparatus with a 380 cm3 equilibration cell and two windows allowing observation of the phase behavior. This cell was equipped with recirculating and expansion loops that were immersed in temperature-controlled liquid and air baths, respectively. Following equilibration, the composition of the sample in each loop was ascertained by gas chromatography. VLE data were acquired for CO2/ethanol and CO2/isopentane binary mixtures within the temperature range from 300 K to 330 K and at pressures up to 7 MPa. These data were used to fit interaction parameters in a Helmholtz energy mixture model. Comparisons were made with the available literature data and values calculated by thermodynamic property models.

On ternary species mixing and combustion in isotropic turbulence at high pressure

NASA Astrophysics Data System (ADS)

Lou, Hong; Miller, Richard S.

2004-05-01

Effects of Soret and Dufour cross-diffusion, whereby both concentration and thermal diffusion occur in the presence of mass fraction, temperature, and pressure gradients, are investigated in the context of both binary and ternary species mixing and combustion in isotropic turbulence at large pressure. The compressible flow formulation is based on a cubic real-gas state equation, and includes generalized forms for heat and mass diffusion derived from nonequilibrium thermodynamics and fluctuation theory. A previously derived formulation of the generalized binary species heat and mass fluxes is first extended to the case of ternary species, and appropriate treatment of the thermal and mass diffusion factors is described. Direct numerical simulations (DNS) are then conducted for both binary and ternary species mixing and combustion in stationary isotropic turbulence. Mean flow temperatures and pressures of =700 K and =45 atm are considered to ensure that all species mixtures remain in the supercritical state such that phase changes do not occur. DNS of ternary species systems undergoing both pure mixing and a simple chemical reaction of the form O2+N2→2NO are then conducted. It is shown that stationary scalar states previously observed for binary mixing persist for the ternary species problem as well; however, the production and magnitude of the scalar variance is found to be altered for the intermediate molecular weight species as compared to the binary species case. The intermediate molecular weight species produces a substantially smaller scalar variance than the remaining species for all flows considered. For combustion of nonstoichiometric mixtures, a binary species mixture, characterized by stationary scalar states, results at long times after the lean reactant is depleted. The form of this final scalar distribution is observed to be similar to that found in the binary flow situation. A series of lower resolution simulations for a variety of species is then used to show the dependence of the stationary scalar variance on the turbulence Reynolds number, turbulence Mach number, species molecular weight ratio, and relative proportion of two species present in the flow after completion of combustion.

Dielectric and physiochemical study of binary mixture of nitrobenzene with toluene

NASA Astrophysics Data System (ADS)

Mohod, Ajay G.; Deshmukh, S. D.; Pattebahadur, K. L.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

2018-05-01

This paper presents the study of binary mixture of Nitrobenzene (NB) with Toluene (TOL) for eleven different concentrations at room temperature. The determined Dielectric Constant (ɛ0) Density (ρ) and Refractive index (nD) values of binary mixture are used to calculate the excess properties i.e. Excess Dielectric Constant (ɛ0E), Excess Molar Volume (VmE), Excess Refractive Index (nDE) and Excess Molar Refraction (RmE) of mixture over the entire composition range and fitted to the Redlich-Kister equation. The Kirkwood Correlation Factor (geff) and other parameters were used to discuss the information about the orientation of dipoles and the solute-solvent interaction of binary mixture at molecular level over the entire range of concentration.

Facile hyphenation of gas chromatography and a microcantilever array sensor for enhanced selectivity.

PubMed

Chapman, Peter J; Vogt, Frank; Dutta, Pampa; Datskos, Panos G; Devault, Gerald L; Sepaniak, Michael J

2007-01-01

The very simple coupling of a standard, packed-column gas chromatograph with a microcantilever array (MCA) is demonstrated for enhanced selectivity and potential analyte identification in the analysis of volatile organic compounds (VOCs). The cantilevers in MCAs are differentially coated on one side with responsive phases (RPs) and produce bending responses of the cantilevers due to analyte-induced surface stresses. Generally, individual components are difficult to elucidate when introduced to MCA systems as mixtures, although pattern recognition techniques are helpful in identifying single components, binary mixtures, or composite responses of distinct mixtures (e.g., fragrances). In the present work, simple test VOC mixtures composed of acetone, ethanol, and trichloroethylene (TCE) in pentane and methanol and acetonitrile in pentane are first separated using a standard gas chromatograph and then introduced into a MCA flow cell. Significant amounts of response diversity to the analytes in the mixtures are demonstrated across the RP-coated cantilevers of the array. Principal component analysis is used to demonstrate that only three components of a four-component VOC mixture could be identified without mixture separation. Calibration studies are performed, demonstrating a good linear response over 2 orders of magnitude for each component in the primary study mixture. Studies of operational parameters including column temperature, column flow rate, and array cell temperature are conducted. Reproducibility studies of VOC peak areas and peak heights are also carried out showing RSDs of less than 4 and 3%, respectively, for intra-assay studies. Of practical significance is the facile manner by which the hyphenation of a mature separation technique and the burgeoning sensing approach is accomplished, and the potential to use pattern recognition techniques with MCAs as a new type of detector for chromatography with analyte-identifying capabilities.

Dielectric and Excess Properties of Glycols with Formamide Binary Mixtures at Different Temperatures

NASA Astrophysics Data System (ADS)

Navarkhele, V. V.

2018-07-01

Dielectric constant measurements of glycol-formamide binary solutions with various concentrations have been carried out at different temperatures. The dielectric measurement has been achieved at 100 MHz frequency using a sensor which is based on frequency domain reflectomery technique. The excess dielectric constant, Kirkwood correlation factor and Bruggeman factor has also been reported for the binary mixtures. The results show that the dielectric constant of the mixtures increases with increase in the volume fraction of formamide and decreases with increase in temperature. The study also confirms the presence of intermolecular interaction, hydrogen bonding and orientation of the dipoles in the binary mixtures.

Dielectric properties of binary mixtures of ethylene glycol monophenyl ether and methanol

NASA Astrophysics Data System (ADS)

Vaghela, K. C.; Vankar, H. P.; Trivedi, C. M.; Rana, V. A.

2017-05-01

Static permittivity (ɛ0) and permittivity at optical frequency (ɛ∞) of ethylene glycol monophenyl ether (EGMPE), methanol (MeOH) and their binary mixtures of varying concentrations have been measured at room temperature (T=299.15 K). The investigation showed a systematic change in permittivity with change in concentration of MeOH in binary mixture system. Measured data have been used to calculate the various dielectric parameters such as E E excess static permittivity (ɛ0E), excess permittivity at optical frequency (ɛ∞E) and Bruggeman factor (fB). Determined parameters provided some information about the molecular interaction among the molecular species of the binary mixtures.

Effect of CMC addition on steady and dynamic shear rheological properties of binary systems of xanthan gum and guar gum.

PubMed

Bak, J H; Yoo, B

2018-04-12

The effect of CMC on the steady and dynamic shear rheological properties of binary mixtures of XG and GG was examined at different mixing ratios. All XG-GG-CMC ternary mixtures had high shear-thinning behavior and the n value of the sample with 5% CMC was the smallest compared with those of other samples. A marked increase in K and η a,50 values was observed for ternary mixtures at a lower content (5%) of CMC, indicating that the synergistic interactions of the XG-GG binary mixture were affected by the content of CMC. The effect of temperature on the η a,50 was well described by the Arrhenius equation for all samples. The activation energy values of all ternary gum mixtures are higher than that of binary gum mixture, and these values also decreased with an increase in CMC content from 5 to 15%. The dynamic moduli of ternary gum mixtures decreased with an increase in CMC content. The tan δ value of the ternary gum mixture with 5% CMC was much lower than those of other ternary mixtures. In general, these results suggest that the flow and dynamic shear rheological properties of XG-GG binary mixtures are strongly influenced by a small addition of CMC. Copyright © 2018. Published by Elsevier B.V.

Numerical modeling and optimization of the Iguassu gas centrifuge

NASA Astrophysics Data System (ADS)

Bogovalov, S. V.; Borman, V. D.; Borisevich, V. D.; Tronin, V. N.; Tronin, I. V.

2017-07-01

The full procedure of the numerical calculation of the optimized parameters of the Iguassu gas centrifuge (GC) is under discussion. The procedure consists of a few steps. On the first step the problem of a hydrodynamical flow of the gas in the rotating rotor of the GC is solved numerically. On the second step the problem of diffusion of the binary mixture of isotopes is solved. The separation power of the gas centrifuge is calculated after that. On the last step the time consuming procedure of optimization of the GC is performed providing us the maximum of the separation power. The optimization is based on the BOBYQA method exploring the results of numerical simulations of the hydrodynamics and diffusion of the mixture of isotopes. Fast convergence of calculations is achieved due to exploring of a direct solver at the solution of the hydrodynamical and diffusion parts of the problem. Optimized separative power and optimal internal parameters of the Iguassu GC with 1 m rotor were calculated using the developed approach. Optimization procedure converges in 45 iterations taking 811 minutes.

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

NASA Astrophysics Data System (ADS)

Okamoto, Ryuichi; Onuki, Akira

2016-06-01

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

Study of intermolecular interactions in binary mixtures of ethanol in methanol

NASA Astrophysics Data System (ADS)

Maharolkar, Aruna P.; Khirade, P. W.; Murugkar, A. G.

2016-05-01

Present paper deals with study of physicochemical properties like viscosity, density and refractive index for the binary mixtures of ethanol and methanol over the entire concentration range were measured at 298.15 K. The experimental data further used to determine the excess properties viz. excess molar volume, excess viscosity, excess molar refraction. The values of excess properties further fitted with Redlich-Kister (R-K Fit) equation to calculate the binary coefficients and standard deviation. The resulting excess parameters are used to indicate the presence of intermolecular interactions and strength of intermolecular interactions between the molecules in the binary mixtures. Excess parameters indicate structure making factor in the mixture predominates in the system.

Densities, Excess Molar Volumes, Viscosities, and Refractive Indices of Binary Mixtures of n-Butyl Acetate with 1-Chloroalkanes (C4-C8) at 298.15 K

NASA Astrophysics Data System (ADS)

Iloukhani, H.; Khanlarzadeh, K.; Rakhshi, M.

2011-03-01

Densities, viscosities, and refractive indices of binary mixtures of n-butyl acetate (1) +1-chlorobutane (2), +1-chloropentane (2), +1-chlorohexane (2), +1-chloroheptane (2), and +1-chlorooctane (2) were measured at 298.15 K for the liquid region and at ambient pressure for the whole composition range. The excess molar volumes V E were calculated from experimental densities. McAllister's three-body interaction, and Hind and Grunberg-Nissan models are used for correlating the viscosity of binary mixtures. The experimental data of binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

Individual and binary toxicity of anatase and rutile nanoparticles towards Ceriodaphnia dubia.

PubMed

Iswarya, V; Bhuvaneshwari, M; Chandrasekaran, N; Mukherjee, Amitava

2016-09-01

Increasing usage of engineered nanoparticles, especially Titanium dioxide (TiO2) in various commercial products has necessitated their toxicity evaluation and risk assessment, especially in the aquatic ecosystem. In the present study, a comprehensive toxicity assessment of anatase and rutile NPs (individual as well as a binary mixture) has been carried out in a freshwater matrix on Ceriodaphnia dubia under different irradiation conditions viz., visible and UV-A. Anatase and rutile NPs produced an LC50 of about 37.04 and 48mg/L, respectively, under visible irradiation. However, lesser LC50 values of about 22.56 (anatase) and 23.76 (rutile) mg/L were noted under UV-A irradiation. A toxic unit (TU) approach was followed to determine the concentrations of binary mixtures of anatase and rutile. The binary mixture resulted in an antagonistic and additive effect under visible and UV-A irradiation, respectively. Among the two different modeling approaches used in the study, Marking-Dawson model was noted to be a more appropriate model than Abbott model for the toxicity evaluation of binary mixtures. The agglomeration of NPs played a significant role in the induction of antagonistic and additive effects by the mixture based on the irradiation applied. TEM and zeta potential analysis confirmed the surface interactions between anatase and rutile NPs in the mixture. Maximum uptake was noticed at 0.25 total TU of the binary mixture under visible irradiation and 1 TU of anatase NPs for UV-A irradiation. Individual NPs showed highest uptake under UV-A than visible irradiation. In contrast, binary mixture showed a difference in the uptake pattern based on the type of irradiation exposed. Copyright © 2016 Elsevier B.V. All rights reserved.

A study of the kinetics and isotherms for Cr(VI) adsorption in a binary mixture of Cr(VI)-Ni(II) using hierarchical porous carbon obtained from pig bone.

PubMed

Li, Chengxian; Huang, Zhe; Huang, Bicheng; Liu, Changfeng; Li, Chengming; Huang, Yaqin

2014-01-01

Cr(VI) adsorption in a binary mixture Cr(VI)-Ni(II) using the hierarchical porous carbon prepared from pig bone (HPC) was investigated. The various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as initial concentration, pH, temperature and contact time were analyzed. The results showed excellent efficiency of Cr(VI) adsorption by HPC. The kinetics and isotherms for Cr(VI) adsorption from a binary mixture Cr(VI)-Ni(II) by HPC were studied. The adsorption equilibrium described by the Langmuir isotherm model is better than that described by the Freundlich isotherm model for the binary mixture in this study. The maximum adsorption capacity was reliably found to be as high as 192.68 mg/g in the binary mixture at pH 2. On fitting the experimental data to both pseudo-first- and second-order equations, the regression analysis of the second-order equation gave a better R² value.

Probing Intermolecular Interactions in Binary Liquid Mixtures Using Femtosecond Laser-Induced Self-Defocusing.

PubMed

Maurya, Sandeep Kumar; Das, Dhiman; Goswami, Debabrata

2016-06-13

Photo-thermal behavior of binary liquid mixtures has been studied by high repetition rate (HRR) Z-scan technique with femtosecond laser pulses. Changes in the peak-valley difference in transmittance (ΔT P-V ) for closed aperture Z-scan experiments are indicative of thermal effects induced by HRR femtosecond laser pulses. We show such indicative results can have a far-reaching impact on molecular properties and intermolecular interactions in binary liquid mixtures. Spectroscopic parameters derived from this experimental technique show that the combined effect of physical and molecular properties of the constituent binary liquids can be related to the components of the binary liquid. © The Author(s) 2016.

Separation of methane-nitrogen mixtures using synthesis vertically aligned carbon nanotube membranes

NASA Astrophysics Data System (ADS)

Gilani, Neda; Daryan, Jafar Towfighi; Rashidi, Alimorad; Omidkhah, Mohammad Reza

2012-03-01

In this paper, capabilities of carbon nanotube (CNT) membranes fabricated in cylindrical pores of anodic aluminum oxide (AAO) substrate to separate the binary mixtures of CH4/N2 are studied experimentally. For this purpose, the permeability and selectivity of three CNT/AAO membranes with different growth time as 6 h, 12 h and 18 h are investigated. CNTs are grown vertically through holes of AAO with average pore diameter of 45 nm by chemical vapor deposition (CVD) of acetylene gas. CNT/AAO membranes with the same CNTs' outer diameters and different inner diameters are synthesized. The AAO are characterized by SEM analysis. In addition, SEM, TEM, BET N2 adsorption analysis and Raman spectroscopy are employed to characterize aligned CNTs. Study on permeability and selectivity of membranes for three binary mixtures of CH4/N2 showed that when the CNT inner diameters are 34 nm and 24 nm, viscous flow is the governing mechanism and insignificant selectivities of 1.2-1.24 are achieved. However, the membrane with CNT inner diameter and wall thickness of 8 nm and 16 nm respectively is considerably selective for CH4 over N2. It was also found that CH4 mole fraction in the feed and upstream feed pressure have major effect on permeability and selectivity. The membrane with 18 h synthesis time showed the selectivity is in the range of 1.8-3.85. The enhancement factor for N2 single gas diffusivity was also found to be about three times larger than that predicted by Knudsen diffusion model.

Self-diffusion Coefficient and Structure of Binary n-Alkane Mixtures at the Liquid-Vapor Interfaces.

PubMed

Chilukoti, Hari Krishna; Kikugawa, Gota; Ohara, Taku

2015-10-15

The self-diffusion coefficient and molecular-scale structure of several binary n-alkane liquid mixtures in the liquid-vapor interface regions have been examined using molecular dynamics simulations. It was observed that in hexane-tetracosane mixture hexane molecules are accumulated in the liquid-vapor interface region and the accumulation intensity decreases with increase in a molar fraction of hexane in the examined range. Molecular alignment and configuration in the interface region of the liquid mixture change with a molar fraction of hexane. The self-diffusion coefficient in the direction parallel to the interface of both tetracosane and hexane in their binary mixture increases in the interface region. It was found that the self-diffusion coefficient of both tetracosane and hexane in their binary mixture is considerably higher in the vapor side of the interface region as the molar fraction of hexane goes lower, which is mostly due to the increase in local free volume caused by the local structure of the liquid in the interface region.

Hydrodynamic flow of ions and atoms in partially ionized plasmas.

PubMed

Nemirovsky, R A; Fredkin, D R; Ron, A

2002-12-01

We have derived the hydrodynamic equations of motion for a partially ionized plasma, when the ionized component and the neutral components have different flow velocities and kinetic temperatures. Starting from the kinetic equations for a gas of ions and a gas of atoms we have considered various processes of encounters between the two species: self-collisions, interspecies collisions, ionization, recombination, and charge exchange. Our results were obtained by developing a general approach for the hydrodynamics of a gas in a binary mixture, in particular when the components drift with respect to each other. This was applied to a partially ionized plasma, when the neutral-species gas and the charged-species gas have separate velocities. We have further suggested a generalized version of the relaxation time approximation and obtained the contributions of the interspecies encounters to the transport equations.

Determination of the rate of crystal growth from the gas phase under conditions of turbulent free convection

NASA Astrophysics Data System (ADS)

Alad'Ev, S. I.

1987-04-01

Crystal growth in vertical and horizontal cylindrical vials, with the substrate and the source serving as the vial ends, is investigated analytically, assuming that the medium consists of a binary mixture of an active and an inert gas. The active gas is made up of the gaseous products of reactions taking place at the substrate and at the source. It is shown that turbulent free convection leads to an increase in crystal growth rate. All other conditions being equal, crystal growth in vertical vials is greater than that in horizontal ones; in both cases crystal growth rate increases with the vial radius, temperature gradient in the gas phase, and gas phase density. The results are compared with experimental data on the growth of Ge crystals in the Ge-GeI4 system.

Hydraulic and separation characteristics of an industrial gas centrifuge calculated with neural networks

NASA Astrophysics Data System (ADS)

Butov, Vladimir; Timchenko, Sergey; Ushakov, Ivan; Golovkov, Nikita; Poberezhnikov, Andrey

2018-03-01

Single gas centrifuge (GC) is generally used for the separation of binary mixtures of isotopes. Processes taking place within the centrifuge are complex and non-linear. Their characteristics can change over time with long-term operation due to wear of the main structural elements of the GC construction. The paper is devoted to the determination of basic operation parameters of the centrifuge with the help of neural networks. We have developed a method for determining the parameters of the industrial GC operation by processing statistical data. In this work, we have constructed a neural network that is capable of determining the main hydraulic and separation characteristics of the gas centrifuge, depending on the geometric dimensions of the gas centrifuge, load value, and rotor speed.

Reducing Dangerous Effects of Unsymmetrical Dimethyl Hydrazine as a Liquid Propellant by Addition of Hydroxyethylhydrazine, Part II, Performance with Several Oxidizers

NASA Astrophysics Data System (ADS)

Keshavarz, Mohammad Hossein; Ramadan, Alireza; Mousaviazar, Ali; Zali, Abbas; Shokrollahi, Arash

2011-07-01

This work continues the study of suitable binary liquid mixtures of unsymmetrical dimethylhydrazine (UDMH) and hydroxyethylhydrazine (HEH) to reduce the harmful effects of pure UDMH. The synthesized HEH was mixed with UDMH up to 40 wt% of HEH to study the performance and properties of binary liquid mixtures of UDMH/HEH. The existence of strong hydrogen bonding between HEH and UDMH provides low-volatile mixtures of these hydrazine derivatives. The addition of HEH significantly reduces the vapor pressure of UDMH, thus reducing the known UDMH health risk to inhalation exposure. Specific impulse was used to study performance of binary mixture UDMH/HEH with respect to pure UDMH. A binary mixture of UDMH/HEH reacts spontaneously in contact with nitrogen tetroxide, red fuming nitric acid (RFNA), and inhibited red fuming nitric acid (IRFNA).

Using Delaunay triangulation and Voronoi tessellation to predict the toxicities of binary mixtures containing hormetic compound

NASA Astrophysics Data System (ADS)

Qu, Rui; Liu, Shu-Shen; Zheng, Qiao-Feng; Li, Tong

2017-03-01

Concentration addition (CA) was proposed as a reasonable default approach for the ecological risk assessment of chemical mixtures. However, CA cannot predict the toxicity of mixture at some effect zones if not all components have definite effective concentrations at the given effect, such as some compounds induce hormesis. In this paper, we developed a new method for the toxicity prediction of various types of binary mixtures, an interpolation method based on the Delaunay triangulation (DT) and Voronoi tessellation (VT) as well as the training set of direct equipartition ray design (EquRay) mixtures, simply IDVequ. At first, the EquRay was employed to design the basic concentration compositions of five binary mixture rays. The toxic effects of single components and mixture rays at different times and various concentrations were determined by the time-dependent microplate toxicity analysis. Secondly, the concentration-toxicity data of the pure components and various mixture rays were acted as a training set. The DT triangles and VT polygons were constructed by various vertices of concentrations in the training set. The toxicities of unknown mixtures were predicted by the linear interpolation and natural neighbor interpolation of vertices. The IDVequ successfully predicted the toxicities of various types of binary mixtures.

Thermodynamics and structural transition of binary atomic Bose-Fermi mixtures in box or harmonic potentials: A path-integral study

NASA Astrophysics Data System (ADS)

Kim, Tom; Chien, Chih-Chun

2018-03-01

Experimental realizations of a variety of atomic binary Bose-Fermi mixtures have brought opportunities for studying composite quantum systems with different spin statistics. The binary atomic mixtures can exhibit a structural transition from a mixture into phase separation as the boson-fermion interaction increases. By using a path-integral formalism to evaluate the grand partition function and the thermodynamic grand potential, we obtain the effective potential of binary Bose-Fermi mixtures. Thermodynamic quantities in a broad range of temperatures and interactions are also derived. The structural transition can be identified as a loop of the effective potential curve, and the volume fraction of phase separation can be determined by the lever rule. For 6Li-7Li and 6Li-41K mixtures, we present the phase diagrams of the mixtures in a box potential at zero and finite temperatures. Due to the flexible densities of atomic gases, the construction of phase separation is more complicated when compared to conventional liquid or solid mixtures where the individual densities are fixed. For harmonically trapped mixtures, we use the local density approximation to map out the finite-temperature density profiles and present typical trap structures, including the mixture, partially separated phases, and fully separated phases.

Using Delaunay triangulation and Voronoi tessellation to predict the toxicities of binary mixtures containing hormetic compound

PubMed Central

Qu, Rui; Liu, Shu-Shen; Zheng, Qiao-Feng; Li, Tong

2017-01-01

Concentration addition (CA) was proposed as a reasonable default approach for the ecological risk assessment of chemical mixtures. However, CA cannot predict the toxicity of mixture at some effect zones if not all components have definite effective concentrations at the given effect, such as some compounds induce hormesis. In this paper, we developed a new method for the toxicity prediction of various types of binary mixtures, an interpolation method based on the Delaunay triangulation (DT) and Voronoi tessellation (VT) as well as the training set of direct equipartition ray design (EquRay) mixtures, simply IDVequ. At first, the EquRay was employed to design the basic concentration compositions of five binary mixture rays. The toxic effects of single components and mixture rays at different times and various concentrations were determined by the time-dependent microplate toxicity analysis. Secondly, the concentration-toxicity data of the pure components and various mixture rays were acted as a training set. The DT triangles and VT polygons were constructed by various vertices of concentrations in the training set. The toxicities of unknown mixtures were predicted by the linear interpolation and natural neighbor interpolation of vertices. The IDVequ successfully predicted the toxicities of various types of binary mixtures. PMID:28287626

Formation of H2-He substellar bodies in cold conditions. Gravitational stability of binary mixtures in a phase transition

NASA Astrophysics Data System (ADS)

Füglistaler, A.; Pfenniger, D.

2016-06-01

Context. Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as large as comets or even planets. However, He has very different chemical properties and no phase transition is expected before H2 in dense interstellar medium conditions. The gravitational stability of fluid mixtures has been studied before, but these studies did not include a phase transition. Aims: We study the gravitational stability of binary fluid mixtures with special emphasis on when one component is in a phase transition. The numerical results are aimed at applications in molecular cloud conditions, but the theoretical results are more general. Methods: First, we study the gravitational stability of van der Waals fluid mixtures using linearized analysis and examine virial equilibrium conditions using the Lennard-Jones intermolecular potential. Then, combining the Lennard-Jones and gravitational potentials, the non-linear dynamics of fluid mixtures are studied via computer simulations using the molecular dynamics code LAMMPS. Results: Along with the classical, ideal-gas Jeans instability criterion, a fluid mixture is always gravitationally unstable if it is in a phase transition because compression does not increase pressure. However, the condensed phase fraction increases. In unstable situations the species can separate: in some conditions He precipitates faster than H2, while in other conditions the converse occurs. Also, for an initial gas phase collapse the geometry is essential. Contrary to spherical or filamentary collapses, sheet-like collapses starting below 15 K easily reach H2 condensation conditions because then they are fastest and both the increase of heating and opacity are limited. Conclusions: Depending on density, temperature and mass, either rocky H2 planetoids, or gaseous He planetoids form. H2 planetoids are favoured by high density, low temperature and low mass, while He planetoids need more mass and can form at temperature well above the critical value.

Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge.

PubMed

Jung, Hee Joon; Huh, June; Park, Cheolmin

2012-10-21

This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm(-1)). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories.

Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge

NASA Astrophysics Data System (ADS)

Jung, Hee Joon; Huh, June; Park, Cheolmin

2012-09-01

This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm-1). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories.

Process for forming shaped group III-V semiconductor nanocrystals, and product formed using process

DOEpatents

Alivisatos, A. Paul; Peng, Xiaogang; Manna, Liberato

2001-01-01

A process for the formation of shaped Group III-V semiconductor nanocrystals comprises contacting the semiconductor nanocrystal precursors with a liquid media comprising a binary mixture of phosphorus-containing organic surfactants capable of promoting the growth of either spherical semiconductor nanocrystals or rod-like semiconductor nanocrystals, whereby the shape of the semiconductor nanocrystals formed in said binary mixture of surfactants is controlled by adjusting the ratio of the surfactants in the binary mixture.

Process for forming shaped group II-VI semiconductor nanocrystals, and product formed using process

DOEpatents

Alivisatos, A. Paul; Peng, Xiaogang; Manna, Liberato

2001-01-01

A process for the formation of shaped Group II-VI semiconductor nanocrystals comprises contacting the semiconductor nanocrystal precursors with a liquid media comprising a binary mixture of phosphorus-containing organic surfactants capable of promoting the growth of either spherical semiconductor nanocrystals or rod-like semiconductor nanocrystals, whereby the shape of the semiconductor nanocrystals formed in said binary mixture of surfactants is controlled by adjusting the ratio of the surfactants in the binary mixture.

Generation of two-dimensional binary mixtures in complex plasmas

NASA Astrophysics Data System (ADS)

Wieben, Frank; Block, Dietmar

2016-10-01

Complex plasmas are an excellent model system for strong coupling phenomena. Under certain conditions the dust particles immersed into the plasma form crystals which can be analyzed in terms of structure and dynamics. Previous experiments focussed mostly on monodisperse particle systems whereas dusty plasmas in nature and technology are polydisperse. Thus, a first and important step towards experiments in polydisperse systems are binary mixtures. Recent experiments on binary mixtures under microgravity conditions observed a phase separation of particle species with different radii even for small size disparities. This contradicts several numerical studies of 2D binary mixtures. Therefore, dedicated experiments are required to gain more insight into the physics of polydisperse systems. In this contribution first ground based experiments on two-dimensional binary mixtures are presented. Particular attention is paid to the requirements for the generation of such systems which involve the consideration of the temporal evolution of the particle properties. Furthermore, the structure of these two-component crystals is analyzed and compared to simulations. This work was supported by the Deutsche Forschungsgemeinschaft DFG in the framework of the SFB TR24 Greifswald Kiel, Project A3b.

Assessment of combined antiandrogenic effects of binary parabens mixtures in a yeast-based reporter assay.

PubMed

Ma, Dehua; Chen, Lujun; Zhu, Xiaobiao; Li, Feifei; Liu, Cong; Liu, Rui

2014-05-01

To date, toxicological studies of endocrine disrupting chemicals (EDCs) have typically focused on single chemical exposures and associated effects. However, exposure to EDCs mixtures in the environment is common. Antiandrogens represent a group of EDCs, which draw increasing attention due to their resultant demasculinization and sexual disruption of aquatic organisms. Although there are a number of in vivo and in vitro studies investigating the combined effects of antiandrogen mixtures, these studies are mainly on selected model compounds such as flutamide, procymidone, and vinclozolin. The aim of the present study is to investigate the combined antiandrogenic effects of parabens, which are widely used antiandrogens in industrial and domestic commodities. A yeast-based human androgen receptor (hAR) assay (YAS) was applied to assess the antiandrogenic activities of n-propylparaben (nPrP), iso-propylparaben (iPrP), methylparaben (MeP), and 4-n-pentylphenol (PeP), as well as the binary mixtures of nPrP with each of the other three antiandrogens. All of the four compounds could exhibit antiandrogenic activity via the hAR. A linear interaction model was applied to quantitatively analyze the interaction between nPrP and each of the other three antiandrogens. The isoboles method was modified to show the variation of combined effects as the concentrations of mixed antiandrogens were changed. Graphs were constructed to show isoeffective curves of three binary mixtures based on the fitted linear interaction model and to evaluate the interaction of the mixed antiandrogens (synergism or antagonism). The combined effect of equimolar combinations of the three mixtures was also considered with the nonlinear isoboles method. The main effect parameters and interaction effect parameters in the linear interaction models of the three mixtures were different from zero. The results showed that any two antiandrogens in their binary mixtures tended to exert equal antiandrogenic activity in the linear concentration ranges. The antiandrogenicity of the binary mixture and the concentration of nPrP were fitted to a sigmoidal model if the concentrations of the other antiandrogens (iPrP, MeP, and PeP) in the mixture were lower than the AR saturation concentrations. Some concave isoboles above the additivity line appeared in all the three mixtures. There were some synergistic effects of the binary mixture of nPrP and MeP at low concentrations in the linear concentration ranges. Interesting, when the antiandrogens concentrations approached the saturation, the interaction between chemicals were antagonistic for all the three mixtures tested. When the toxicity of the three mixtures was assessed using nonlinear isoboles, only antagonism was observed for equimolar combinations of nPrP and iPrP as the concentrations were increased from the no-observed-effect-concentration (NOEC) to effective concentration of 80%. In addition, the interactions were changed from synergistic to antagonistic as effective concentrations were increased in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP. The combined effects of three binary antiandrogens mixtures in the linear ranges were successfully evaluated by curve fitting and isoboles. The combined effects of specific binary mixtures varied depending on the concentrations of the chemicals in the mixtures. At low concentrations in the linear concentration ranges, there was synergistic interaction existing in the binary mixture of nPrP and MeP. The interaction tended to be antagonistic as the antiandrogens approached saturation concentrations in mixtures of nPrP with each of the other three antiandrogens. The synergistic interaction was also found in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP, at low concentrations with another method of nonlinear isoboles. The mixture activities of binary antiandrogens had a tendency towards antagonism at high concentrations and synergism at low concentrations.

Molecular simulations for adsorption and separation of natural gas in IRMOF-1 and Cu-BTC metal-organic frameworks.

PubMed

Martín-Calvo, Ana; García-Pérez, Elena; Manuel Castillo, Juan; Calero, Sofia

2008-12-21

We use Monte Carlo simulations to study the adsorption and separation of the natural gas components in IRMOF-1 and Cu-BTC metal-organic frameworks. We computed the adsorption isotherms of pure components, binary, and five-component mixtures analyzing the siting of the molecules in the structure for the different loadings. The bulk compositions studied for the mixtures were 50 : 50 and 90 : 10 for CH4-CO2, 90 : 10 for N2-CO2, and 95 : 2.0 : 1.5 : 1.0 : 0.5 for the CH4-C2H6-N2-CO2-C3H8 mixture. We choose this composition because it is similar to an average sample of natural gas. Our simulations show that CO2 is preferentially adsorbed over propane, ethane, methane and N2 in the complete pressure range under study. Longer alkanes are favored over shorter alkanes and the lowest adsorption corresponds to N2. Though IRMOF-1 has a significantly higher adsorption capacity than Cu-BTC, the adsorption selectivity of CO2 over CH4 and N2 is found to be higher in the latter, proving that the separation efficiency is largely affected by the shape, the atomic composition and the type of linkers of the structure.

Unified Description of Dynamics of a Repulsive Two-Component Fermi Gas

NASA Astrophysics Data System (ADS)

Grochowski, Piotr T.; Karpiuk, Tomasz; Brewczyk, Mirosław; Rzążewski, Kazimierz

2017-11-01

We study a binary spin mixture of a zero-temperature repulsively interacting Li 6 atoms using both the atomic-orbital and density-functional approaches. The gas is initially prepared in a configuration of two magnetic domains and we determine the frequency of the spin-dipole oscillations which are emerging after the repulsive barrier, initially separating the domains, is removed. We find, in agreement with recent experiment [G. Valtolina et al., Nat. Phys. 13, 704 (2017), 10.1038/nphys4108], the occurrence of a ferromagnetic instability in an atomic gas while the interaction strength between different spin states is increased, after which the system becomes ferromagnetic. The ferromagnetic instability is preceded by the softening of the spin-dipole mode.

Forage production of grass-legume binary mixtures on Intermountain Western USA irrigated pastures

USDA-ARS?s Scientific Manuscript database

A well-managed irrigated pasture is optimized for forage production with the use of N fertilizer which incurs extra expense. The objective was to determine which binary grass-legume mixture and mixture planting ratio of tall fescue (Festuca arundinacea Schreb.) (TF), meadow brome (Bromus bieberstei...

Relaxation dynamics in a binary hard-ellipse liquid.

PubMed

Xu, Wen-Sheng; Sun, Zhao-Yan; An, Li-Jia

2015-01-21

Structural relaxation in binary hard spherical particles has been shown recently to exhibit a wealth of remarkable features when size disparity or mixture composition is varied. In this paper, we test whether or not similar dynamical phenomena occur in glassy systems composed of binary hard ellipses. We demonstrate via event-driven molecular dynamics simulation that a binary hard-ellipse mixture with an aspect ratio of two and moderate size disparity displays characteristic glassy dynamics upon increasing density in both the translational and the rotational degrees of freedom. The rotational glass transition density is found to be close to the translational one for the binary mixtures investigated. More importantly, we assess the influence of size disparity and mixture composition on the relaxation dynamics. We find that an increase of size disparity leads, both translationally and rotationally, to a speed up of the long-time dynamics in the supercooled regime so that both the translational and the rotational glass transition shift to higher densities. By increasing the number concentration of the small particles, the time evolution of both translational and rotational relaxation dynamics at high densities displays two qualitatively different scenarios, i.e., both the initial and the final part of the structural relaxation slow down for small size disparity, while the short-time dynamics still slows down but the final decay speeds up in the binary mixture with large size disparity. These findings are reminiscent of those observed in binary hard spherical particles. Therefore, our results suggest a universal mechanism for the influence of size disparity and mixture composition on the structural relaxation in both isotropic and anisotropic particle systems.

Research on odor interaction between aldehyde compounds via a partial differential equation (PDE) model.

PubMed

Yan, Luchun; Liu, Jiemin; Qu, Chen; Gu, Xingye; Zhao, Xia

2015-01-28

In order to explore the odor interaction of binary odor mixtures, a series of odor intensity evaluation tests were performed using both individual components and binary mixtures of aldehydes. Based on the linear relation between the logarithm of odor activity value and odor intensity of individual substances, the relationship between concentrations of individual constituents and their joint odor intensity was investigated by employing a partial differential equation (PDE) model. The obtained results showed that the binary odor interaction was mainly influenced by the mixing ratio of two constituents, but not the concentration level of an odor sample. Besides, an extended PDE model was also proposed on the basis of the above experiments. Through a series of odor intensity matching tests for several different binary odor mixtures, the extended PDE model was proved effective at odor intensity prediction. Furthermore, odorants of the same chemical group and similar odor type exhibited similar characteristics in the binary odor interaction. The overall results suggested that the PDE model is a more interpretable way of demonstrating the odor interactions of binary odor mixtures.

Intermolecular forces in acetonitrile + ethanol binary liquid mixtures

NASA Astrophysics Data System (ADS)

Elangovan, A.; Shanmugam, R.; Arivazhagan, G.; Mahendraprabu, A.; Karthick, N. K.

2015-10-01

FTIR spectral measurements have been carried out on the binary mixtures of acetonitrile with ethanol at 1:0 (acetonitrile:ethanol), 1:1, 1:2, 1:3 and 0:1 at room temperature. DFT and isosurface calculations have been performed. The acetonitrile + ethanol binary mixtures consist of 1:1, 1:2, 1:3 and 1:4 complexes formed through both the red and blue shifting H-bonds. Inter as well as intra molecular forces are found to exist in 1:3 and 1:4 complexes.

Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

NASA Astrophysics Data System (ADS)

Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

2014-01-01

The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

Thermodiffusion, molecular diffusion and Soret coefficient of binary and ternary mixtures of n-hexane, n-dodecane and toluene.

PubMed

Alonso de Mezquia, David; Wang, Zilin; Lapeira, Estela; Klein, Michael; Wiegand, Simone; Mounir Bou-Ali, M

2014-11-01

In this study, the thermodiffusion, molecular diffusion, and Soret coefficients of 12 binary mixtures composed of toluene, n-hexane and n-dodecane in the whole range of concentrations at atmospheric pressure and temperatures of 298.15 K and 308.15 K have been determined. The experimental measurements have been carried out using the Thermogravitational Column, the Sliding Symmetric Tubes and the Thermal Diffusion Forced Rayleigh Scattering techniques. The results obtained using the different techniques show a maximum deviation of 9% for the thermodiffusion coefficient, 8% for the molecular diffusion coefficient and 2% for the Soret coefficient. For the first time we report a decrease of the thermodiffusion coefficient with increasing ratio of the thermal expansion coefficient and viscosity for a binary mixture of an organic ring compound with a short n-alkane. This observation is discussed in terms of interactions between the different components. Additionally, the thermogravitational technique has been used to measure the thermodiffusion coefficients of four ternary mixtures consisting of toluene, n-hexane and n-dodecane at 298.15 K. In order to complete the study, the values obtained for the molecular diffusion coefficient in binary mixtures, and the thermodiffusion coefficient of binary and ternary mixtures have been compared with recently derived correlations.

Enzymatic synthesis of 6-O-glucosyl-poly(3-hydroxyalkanoate) in organic solvents and their binary mixture.

PubMed

Gumel, A M; Annuar, M S M; Heidelberg, T

2013-04-01

The effects of organic solvents and their binary mixture in the glucose functionalization of bacterial poly-3-hydroxyalkanoates catalyzed by Lecitase™ Ultra were studied. Equal volume binary mixture of DMSO and chloroform with moderate polarity was more effective for the enzyme catalyzed synthesis of the carbohydrate polymer at ≈38.2 (±0.8)% reactant conversion as compared to the mono-phasic and other binary solvents studied. The apparent reaction rate constant as a function of medium water activity (aw) was observed to increase with increasing solvent polarity, with optimum aw of 0.2, 0.4 and 0.7 (±0.1) observed in hydrophilic DMSO, binary mixture DMSO:isooctane and hydrophobic isooctane, respectively. Molecular sieve loading between 13 to 15gL(-1) (±0.2) and reaction temperature between 40 to 50°C were found optimal. Functionalized PHA polymer showed potential characteristics and biodegradability. Copyright © 2012 Elsevier B.V. All rights reserved.

Viscosity of nonelectrolyte liquid mixtures. III Binary mixtures of methyl methacrylate with hydrocarbons, haloalkanes, and alkylamines

NASA Astrophysics Data System (ADS)

Oswal, S. L.; Patel, B. M.; Shah, H. R.; Oswal, P.

1994-07-01

Measurements of the viscosity η and the density ϱ are reported for 14 binary mixtures of methyl methacrylate (MMA) with hydrocarbons, haloalkanes, and alkylamines at 303.15 K. The viscosity data have been correlated with equations of Grunberg and Nissan, of McAllister, and of Auslaender. Furthermore, excess viscosity Δ In η and excess Gibbs energy of activation ΔG* E of viscous flow have been calculated and have been used to predict molecular interactions occurring in present binary mixtures. The results show the existence of specific interactions in MMA + aromatic hydrocarbons, MMA + haloalkanes, and MMA + primary amines.

Headspace quantification of pure and aqueous solutions of binary mixtures of key volatile organic compounds in Swiss cheeses using selected ion flow tube mass spectrometry.

PubMed

Castada, Hardy Z; Wick, Cheryl; Harper, W James; Barringer, Sheryl

2015-01-15

Twelve volatile organic compounds (VOCs) have recently been identified as key compounds in Swiss cheese with split defects. It is important to know how these VOCs interact in binary mixtures and if their behavior changes with concentration in binary mixtures. Selected ion flow tube mass spectrometry (SIFT-MS) was used for the headspace analysis of VOCs commonly found in Swiss cheeses. Headspace (H/S) sampling and quantification checks using SIFT-MS and further linear regression analyses were carried out on twelve selected aqueous solutions of VOCs. Five binary mixtures of standard solutions of VOCs were also prepared and the H/S profile of each mixture was analyzed. A very good fit of linearity for the twelve VOCs (95% confidence level) confirms direct proportionality between the H/S and the aqueous concentration of the standard solutions. Henry's Law coefficients were calculated with a high degree of confidence. SIFT-MS analysis of five binary mixtures showed that the more polar compounds reduced the H/S concentration of the less polar compounds, while the addition of a less polar compound increased the H/S concentration of the more polar compound. In the binary experiment, it was shown that the behavior of a compound in the headspace can be significantly affected by the presence of another compound. Thus, the matrix effect plays a significant role in the behavior of molecules in a mixed solution. Copyright © 2014 John Wiley & Sons, Ltd.

Relaxation of the accelerating-gas boundary layer to the test-gas boundary layer on a flat plate in an expansion tube

NASA Technical Reports Server (NTRS)

Gupta, R. N.; Trimpi, R. L.

1973-01-01

An analytic investigation of the relaxation of the accelerating-gas boundary layer to the test-gas boundary layer over a flat plate mounted in an expansion tube has been conducted. In this treatment, nitrogen has been considered as the test gas and helium as the accelerating gas. The problem is analyzed in two conically similar limits: (1) when the time lag between the arrival of the shock and the interface at the leading edge of the plate is very large, and (2) when this time lag is negligible. The transient laminar boundary-layer equations of a perfect binary-gas mixture are taken as the flow governing equations. These coupled equations have been solved numerically by Gauss-Seidel line-relaxation method. The results predict the transient behavior as well as the time required for an all-helium accelerating-gas boundary layer to relax to an all-nitrogen boundary layer.

MR imaging of apparent 3He gas transport in narrow pipes and rodent airways

NASA Astrophysics Data System (ADS)

Minard, Kevin R.; Jacob, Richard E.; Laicher, Gernot; Einstein, Daniel R.; Kuprat, Andrew P.; Corley, Richard A.

2008-10-01

High sensitivity makes hyperpolarized 3He an attractive signal source for visualizing gas flow with magnetic resonance (MR) imaging. Its rapid Brownian motion, however, can blur observed flow lamina and alter measured diffusion rates when excited nuclei traverse shear-induced velocity gradients during data acquisition. Here, both effects are described analytically, and predicted values for measured transport during laminar flow through a straight, 3.2-mm diameter pipe are validated using two-dimensional (2D) constant-time images of different binary gas mixtures. Results show explicitly how measured transport in narrow conduits is characterized by apparent values that depend on underlying gas dynamics and imaging time. In ventilated rats, this is found to obscure acquired airflow images. Nevertheless, flow splitting at airway branches is still evident and use of 3D vector flow mapping is shown to reveal surprising detail that highlights the correlation between gas dynamics and lung structure.

Optical Study of the Critical Behaviour of Pure Fluids and Binary Mixtures.

NASA Astrophysics Data System (ADS)

Narger, Ulrike

1990-01-01

Optical techniques were used to study the critical behaviour of the pure fluids CHF_3, CClF_3 and Xe, and binary mixtures He-Xe and nicotine + water. We find that for all these substances, the order parameter is described by a power law in the reduced temperature t = (T _{c} - T)/T_{c} with a leading exponent beta = 0.327 +/- 0.002. Also, we determine the first correction to scaling exponent to be Delta = 0.43 +/- 0.02 for the pure fluids and Delta = 0.50 +/- 0.02 for the He-Xe system. The coexistence curve diameter in CHF _3 and CClF_3 exhibits a deviation from recti-linear diameter, in agreement with a modern theory which interprets this behaviour as resulting from three-body effects. In contrast, no such deviation is observed in Xe where, according to that theory, it should be more pronounced than in other substances. In the polar fluid CHF_3, the order parameter, isothermal compressibility and the chemical potential along the critical isotherm were simultaneously measured in the same experiment in an effort to ensure self-consistency of the results. From the data, two amplitude ratios which are predicted to be universal are determined: Gamma_sp{0}{+} /Gamma_sp{0}{ -} = 4.8 +/- 0.6 and D_0 Gamma_sp{0}{+ } B_sp{0}{delta-1} = 1.66 +/- 0.14. In the binary liquid system nicotine + water, the diffusivity was measured both by light scattering and by interferometry. The results agree qualitatively, but differ by a factor of ~2. From the light scattering data, the critical exponent of the viscosity is found to be z_{eta } = 0.044 +/- 0.008. The interferometric experiments on Xe and He-Xe furnish a direct way to measure the effects of wetting: From the data, the exponent of the surface tension is found to be n = 1.24 +/- 0.06. The similarity of the order parameter and compressibility in Xe and a He-Xe mixture containing 5% He indicate that the phase transition in this He-Xe mixture is of the liquid -gas type rather than the binary liquid type.

Separation of Pr and Nd from La in chloride solution by extraction with a mixture of Cyanex 272 and Alamine 336

NASA Astrophysics Data System (ADS)

Liu, Yang; Jeon, Ho Seok; Lee, Man Seung

2015-09-01

The possibility of separation of Pr and Nd from La in a chloride leaching solution of monazite sand has been investigated by using a binary mixture of Cyanex 272 (bis(2,4,4-trimethylpentyl) phosphinic acid) and Alamine 336 (tri-octyl/decyl amine). The binary mixture showed synergism on the extraction of the three metals and led to an increase in the separation factor between Pr/Nd and La compared to Cyanex 272 alone. Although the addition of chloride ion into aqueous increased the extraction of the metals, this addition had negative effect on the separation of Nd/Pr and La. McCabe-Thiele diagrams for the extraction of Pr and Nd with the binary mixture were constructed. Stripping of metals from the loaded organic phase was achieved with 0.7 M HCl. The difference in the solvent extraction of the rare earth elements from chloride solution between the binary mixture and saponified extractants was also discussed.

Effect of air humidity on the removal of carbon tetrachloride from air using Cu-BTC metal-organic framework.

PubMed

Martín-Calvo, Ana; García-Pérez, Elena; García-Sánchez, Almudena; Bueno-Pérez, Rocío; Hamad, Said; Calero, Sofia

2011-06-21

We have used interatomic potential-based simulations to study the removal of carbon tetrachloride from air at 298 K, using Cu-BTC metal organic framework. We have developed new sets of Lennard-Jones parameters that accurately describe the vapour-liquid equilibrium curves of carbon tetrachloride and the main components from air (oxygen, nitrogen, and argon). Using these parameters we performed Monte Carlo simulations for the following systems: (a) single component adsorption of carbon tetrachloride, oxygen, nitrogen, and argon molecules, (b) binary Ar/CCl(4), O(2)/CCl(4), and N(2)/CCl(4) mixtures with bulk gas compositions 99 : 1 and 99.9 : 0.1, (c) ternary O(2)/N(2)/Ar mixtures with both, equimolar and 21 : 78 : 1 bulk gas composition, (d) quaternary mixture formed by 0.1% of CCl(4) pollutant, 20.979% O(2), 77.922% N(2), and 0.999% Ar, and (e) five-component mixtures corresponding to 0.1% of CCl(4) pollutant in air with relative humidity ranging from 0 to 100%. The carbon tetrachloride adsorption selectivity and the self-diffusivity and preferential sitting of the different molecules in the structure are studied for all the systems.

Gas-liquid phase coexistence and crossover behavior of binary ionic fluids with screened Coulomb interactions.

PubMed

Patsahan, O

2014-06-01

We study the effects of an interaction range on the gas-liquid phase diagram and the crossover behavior of a simple model of ionic fluids: an equimolar binary mixture of equisized hard spheres interacting through screened Coulomb potentials which are repulsive between particles of the same species and attractive between particles of different species. Using the collective variables theory, we find explicit expressions for the relevant coefficients of the effective φ{4} Ginzburg-Landau Hamiltonian in a one-loop approximation. Within the framework of this approximation, we calculate the critical parameters and gas-liquid phase diagrams for varying inverse screening length z. Both the critical temperature scaled by the Yukawa potential contact value and the critical density rapidly decrease with an increase of the interaction range (a decrease of z) and then for z<0.05 they slowly approach the values found for a restricted primitive model (RPM). We find that gas-liquid coexistence region reduces with an increase of z and completely vanishes at z≃2.78. Our results clearly show that an increase in the interaction range leads to a decrease of the crossover temperature. For z≃0.01, the crossover temperature is the same as for the RPM.

Unravelling the Composition Dependent Anomalies of Pair Hydrophobicity in Water-Ethanol Binary Mixtures.

PubMed

Halder, Ritaban; Jana, Biman

2018-06-05

Aqueous binary mixtures have received immense attention in recent years because of their extensive application in several biological and industrial processes. Water-ethanol binary mixture serves as a unique system because it exhibits composition dependent alteration of dynamic and thermodynamic properties. Our present work demonstrates how different compositions of water-ethanol binary mixtures affect the pair hydrophobicity of different hydrophobes. Pair hydrophobicity is measured by the depth of the first minimum (contact minima) of potential of mean force (PMF) profile between two hydrophobes. The pair hydrophobicity is found to be increased with addition of ethanol to water up to mole fraction of 0.10 and decreased with further addition of ethanol. This observation is shown to be true for three different pairs of hydrophobes. Decomposition of PMF into enthalpic and entropic contribution indicates a switch from entropic to enthalpic stabilization of the contact minimum upon addition of ethanol to water. The gain in mixing enthalpy of the binary solvent system upon association of two hydrophobes is found to be the determining factor for the stabilization of contact minimum. Several static/dynamics quantities (average composition fluctuations, diffusion coefficients, fluctuations in total dipole moment, propensity of ethyl-ethyl association, etc) of the ethanol-water binary mixture also show irregularities around xEtOH =0.10-0.15. We have also discovered that the hydrogen bonding pattern of ethanol rather than water reveals a change in trend near the similar composition range. As the anomalous behaviour of the physical/dynamical properties along with the pair hydrophobicity in aqueous binary mixture of amphiphilic solutes is common phenomena, our results may provide a general viewpoint on these aspects.

MULTISUBSTRATE BIODEGRADATION KINETICS FOR BINARY AND COMPLEX MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

Biodegradation kinetics were studied for binary and complex mixtures of nine polycyclic aromatic hydrocarbons (PAHs): naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, phenanthrene, anthracene, pyrene, fluorene and fluoranthene. Discrepancies between the ...

Binary Mixtures of Particles with Different Diffusivities Demix.

PubMed

Weber, Simon N; Weber, Christoph A; Frey, Erwin

2016-02-05

The influence of size differences, shape, mass, and persistent motion on phase separation in binary mixtures has been intensively studied. Here we focus on the exclusive role of diffusivity differences in binary mixtures of equal-sized particles. We find an effective attraction between the less diffusive particles, which are essentially caged in the surrounding species with the higher diffusion constant. This effect leads to phase separation for systems above a critical size: A single close-packed cluster made up of the less diffusive species emerges. Experiments for testing our predictions are outlined.

Viscosities of nonelectrolyte liquid mixtures. II. Binary and quaternary systems of some n-alkanes

NASA Astrophysics Data System (ADS)

Wakefield, D. L.; Marsh, K. N.; Zwolinski, B. J.

1988-01-01

This paper is the second in a series of viscosity and density studies on multicomponent mixtures of n-alkanes from 303 to 338 K. Reported here are the results of binary mixtures of n-tetracosane + n-octane as well as quaternary mixtures of n-tetracosane + n-octane + n-decane + n-hexane at 318.16, 328.16, and 338.16 K. Viscosities were determined using a standard U-tube Ostwald viscometer, and densities were determined using a flask-type pycnometer. Empirical relations tested include the Grunberg and Nissan equation and the method of corresponding states. In addition, comparisons were made regarding the behavior of this quaternary system and homologous binary mixtures of n-hexadecane + n-octane and n-tetracosane + n-octane at the same temperatures.

ANALYSES OF THE INTERACTIONS WITHIN BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3H10T1/2CL8 CELLS

EPA Science Inventory

ANALYSES OF THE INTERACTIONS WITHIN BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3HIOT1/2 CL8 CELLS.

Studies of defined mixtures of carcinogenic polycyclic aromatic hydrocarbons (PAH) have identified three major categories of interacti...

Synergistic toxicity and physiological impact of imidacloprid alone and binary mixtures with seven representative pesticides on honey bee (Apis mellifera)

USDA-ARS?s Scientific Manuscript database

Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL) alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures ...

Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method.

PubMed

Selvaraju, R; Raja, A; Thiruppathi, G

2013-10-01

In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. Copyright © 2013 Elsevier B.V. All rights reserved.

Monte Carlo study of four dimensional binary hard hypersphere mixtures

NASA Astrophysics Data System (ADS)

Bishop, Marvin; Whitlock, Paula A.

2012-01-01

A multithreaded Monte Carlo code was used to study the properties of binary mixtures of hard hyperspheres in four dimensions. The ratios of the diameters of the hyperspheres examined were 0.4, 0.5, 0.6, and 0.8. Many total densities of the binary mixtures were investigated. The pair correlation functions and the equations of state were determined and compared with other simulation results and theoretical predictions. At lower diameter ratios the pair correlation functions of the mixture agree with the pair correlation function of a one component fluid at an appropriately scaled density. The theoretical results for the equation of state compare well to the Monte Carlo calculations for all but the highest densities studied.

The scent of mixtures: rules of odour processing in ants

PubMed Central

Perez, Margot; Giurfa, Martin; d'Ettorre, Patrizia

2015-01-01

Natural odours are complex blends of numerous components. Understanding how animals perceive odour mixtures is central to multiple disciplines. Here we focused on carpenter ants, which rely on odours in various behavioural contexts. We studied overshadowing, a phenomenon that occurs when animals having learnt a binary mixture respond less to one component than to the other, and less than when this component was learnt alone. Ants were trained individually with alcohols and aldehydes varying in carbon-chain length, either as single odours or binary mixtures. They were then tested with the mixture and the components. Overshadowing resulted from the interaction between chain length and functional group: alcohols overshadowed aldehydes, and longer chain lengths overshadowed shorter ones; yet, combinations of these factors could cancel each other and suppress overshadowing. Our results show how ants treat binary olfactory mixtures and set the basis for predictive analyses of odour perception in insects. PMID:25726692

Comparison studies on the percolation thresholds of binary mixture tablets containing excipients of plastic/brittle and plastic/plastic deformation properties.

PubMed

Amin, Mohd C I; Fell, John T

2004-01-01

Percolation theory has been used with great interest in understanding the design and characterization of dosage forms. In this study, work has been carried out to investigate the behavior of binary mixture tablets containing excipients of similar and different deformation properties. The binary mixture tablets were prepared by direct compression using lactose, polyvinyl chloride (PVC), Eudragit RS 100, and microcrystalline cellulose (MCC). The application of percolation theory on the relationships between compactibility, Pmax, or compression susceptibility (compressibility), gamma, and mixture compositions reveals the presence of percolation thresholds even for mixtures of similar deformation properties. The results showed that all mixture compositions exhibited at least one discreet change in the slope, which was referred to as the percolation threshold. The PVC/Eudragit RS100 mixture compositions showed significant percolation threshold at 80% (w/w) PVC loading. Two percolation thresholds were observed from a series of binary mixtures containing similar plastic deformation materials (PVC/MCC). The percolation thresholds were determined at 20% (w/w) and 80% (w/w) PVC loading. These are areas where one of the components percolates throughout the system and the properties of the tablets are expected to experience a sudden change. Experimental results, however, showed that total disruption of the tablet physical properties at the specified percolation thresholds can be observed for PVC/lactose mixtures at 20-30% (w/w) loading while only minor changes in the tablets' strength for PVC/MCC or PVC/Eudragit RS 100 mixtures were observed.

Intrinsic viscosity of binary gum mixtures with xanthan gum and guar gum: Effect of NaCl, sucrose, and pH.

PubMed

Bak, J H; Yoo, B

2018-05-01

The intrinsic viscosity ([η]) values of binary gum mixtures with xanthan gum (XG) and guar gum (GG) mixed with NaCl and sucrose at different concentrations as well as in the presence of different pH levels were examined in dilute solution as a function of XG/GG mixing ratio (100/0, 75/25, 50/50, and 0/100). Experimental values of concentration (C) and relative viscosity (η rel ) or specific viscosity (η sp ) of gums in dilute solution were fitted to five models to determine [η] values of binary gum mixtures including individual gums. A [η] model (η rel =1+[η]C) of Tanglertpaibul and Rao is recommended as the best model to estimate [η] values for the binary gum mixtures with XG and GG as affected by NaCl, sucrose, and pH. Overall, the synergistic interaction of XG-GG mixtures in the presence of NaCl and sucrose showed a greatly positive variation between measured and calculated values of [η]. In contrast, the binary gum mixtures showed synergy only under an acidic condition (pH3). These results suggest that the NaCl and sucrose addition or acidic condition appears to affect the intermolecular interaction occurred between XG and GG at different gum mixing ratios. Copyright © 2018 Elsevier B.V. All rights reserved.

Performance of a MICROMEGAS-based TPC in a high-energy neutron beam

NASA Astrophysics Data System (ADS)

Snyder, L.; Manning, B.; Bowden, N. S.; Bundgaard, J.; Casperson, R. J.; Cebra, D. A.; Classen, T.; Duke, D. L.; Gearhart, J.; Greife, U.; Hagmann, C.; Heffner, M.; Hensle, D.; Higgins, D.; Isenhower, D.; King, J.; Klay, J. L.; Geppert-Kleinrath, V.; Loveland, W.; Magee, J. A.; Mendenhall, M. P.; Sangiorgio, S.; Seilhan, B.; Schmitt, K. T.; Tovesson, F.; Towell, R. S.; Walsh, N.; Watson, S.; Yao, L.; Younes, W.

2018-02-01

The MICROMEGAS (MICRO-MEsh GAseous Structure) charge amplification structure has found wide use in many detection applications, especially as a gain stage for the charge readout of Time Projection Chambers (TPCs). Here we report on the behavior of a MICROMEGAS TPC when operated in a high-energy (up to 800 MeV) neutron beam. It is found that neutron-induced reactions can cause discharges in some drift gas mixtures that are stable in the absence of the neutron beam. The discharges result from recoil ions close to the MICROMEGAS that deposit high specific ionization density and have a limited diffusion time. For a binary drift gas, increasing the percentage of the molecular component (quench gas) relative to the noble component and operating at lower pressures generally improves stability.

Observation of Spin Superfluidity in a Bose Gas Mixture

NASA Astrophysics Data System (ADS)

Fava, Eleonora; Bienaimé, Tom; Mordini, Carmelo; Colzi, Giacomo; Qu, Chunlei; Stringari, Sandro; Lamporesi, Giacomo; Ferrari, Gabriele

2018-04-01

The spin dynamics of a harmonically trapped Bose-Einstein condensed binary mixture of sodium atoms is experimentally investigated at finite temperature. In the collisional regime the motion of the thermal component is shown to be damped because of spin drag, while the two condensates exhibit a counterflow oscillation without friction, thereby providing direct evidence for spin superfluidity. Results are also reported in the collisionless regime where the spin components of both the condensate and thermal part oscillate without damping, their relative motion being driven by a mean-field effect. We also measure the static polarizability of the condensed and thermal parts and we find a large increase of the condensate polarizability with respect to the T =0 value, in agreement with the predictions of theory.

Pharmacokinetic Modeling of JP-8 Jet Fuel Components: II. A Conceptual Framework

DTIC Science & Technology

2003-12-01

example, a single type of (simple) binary interaction between 300 components would require the specification of some 105 interaction coefficients . One...individual substances, via binary mechanisms, is enough to predict the interactions present in the mixture. Secondly, complex mixtures can often be...approximated as pseudo- binary systems, consisting of the compound of interest plus a single interacting complex vehicle with well-defined, composite

Cluster kinetics model for mixtures of glassformers

NASA Astrophysics Data System (ADS)

Brenskelle, Lisa A.; McCoy, Benjamin J.

2007-10-01

For glassformers we propose a binary mixture relation for parameters in a cluster kinetics model previously shown to represent pure compound data for viscosity and dielectric relaxation as functions of either temperature or pressure. The model parameters are based on activation energies and activation volumes for cluster association-dissociation processes. With the mixture parameters, we calculated dielectric relaxation times and compared the results to experimental values for binary mixtures. Mixtures of sorbitol and glycerol (seven compositions), sorbitol and xylitol (three compositions), and polychloroepihydrin and polyvinylmethylether (three compositions) were studied.

Solvatochromism and preferential solvation of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone by UV-vis absorption and laser-induced fluorescence measurements

NASA Astrophysics Data System (ADS)

Sasirekha, V.; Vanelle, P.; Terme, T.; Ramakrishnan, V.

2008-12-01

Solvation characteristics of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone ( 1) in pure and binary solvent mixtures have been studied by UV-vis absorption spectroscopy and laser-induced fluorescence techniques. The binary solvent mixtures used as CCl 4 (tetrachloromethane)-DMF ( N, N-dimethylformamide), AN (acetonitrile)-DMSO (dimethylsulfoxide), CHCl 3 (chloroform)-DMSO, CHCl 3-MeOH (methanol), and MeOH-DMSO. The longest wavelength band of 1 has been studied in pure solvents as well as in binary solvent mixtures as a function of the bulk mole fraction. The Vis absorption band maxima show an unusual blue shift with increasing solvent polarity. The emission maxima of 1 show changes with varying the pure solvents and the composition in the case of binary solvent mixtures. Non-ideal solvation characteristics are observed in all binary solvent mixtures. It has been observed that the quantity [ ν-(Xν+Xν)] serves as a measure of the extent of preferential solvation, where ν˜ and X are the position of band maximum in wavenumbers (cm -1) and the bulk mole fraction values, respectively. The preferential solvation parameters local mole fraction ( X2L), solvation index ( δs2), and exchange constant ( k12) are evaluated.

Physicochemical Properties of Glycine-Based Ionic Liquid [QuatGly-OEt][EtOSO3] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate) and Its Binary Mixtures with Poly(ethylene glycol) (Mw = 200) at Various Temperatures

PubMed Central

Wu, Tzi-Yi; Chen, Bor-Kuan; Hao, Lin; Lin, Yuan-Chung; Wang, H. Paul; Kuo, Chung-Wen; Sun, I-Wen

2011-01-01

This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL) [QuatGly-OEt][EtOSO3] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO3] with poly(ethylene glycol) (PEG) [Mw = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO3] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF) equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (VmE ) and deviations (Δη, Δxn, ΔΨn, ΔxR, and ΔΨR) are discussed in terms of molecular interactions and molecular structures in the binary mixture. PMID:22272102

Phase behaviors of binary mixtures composed of electron-rich and electron-poor triphenylene discotic liquid crystals

NASA Astrophysics Data System (ADS)

An, Lingling; Jing, Min; Xiao, Bo; Bai, Xiao-Yan; Zeng, Qing-Dao; Zhao, Ke-Qing

2016-09-01

Disk-like liquid crystals (DLCs) can self-assemble to ordered columnar mesophases and are intriguing one-dimensional organic semiconductors with high charge carrier mobility. To improve their applicable property of mesomorphic temperature ranges, we exploit the binary mixtures of electronic donor-acceptor DLC materials. The electron-rich 2,3,6,7,10,11-hexakis(alkoxy)triphenylenes (C4, C6, C8, C10, C12) and an electron-deficient tetrapentyl triphenylene-2,3,6,10-tetracarboxylate have been prepared and their binary mixtures have been investigated. The mesomorphism of the 1:1 (molar ratio) mixtures has been characterized by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and small angel x-ray scattering (SAXS). The self-assembled monolayer structure of a discogen on a solid-liquid interface has been imaged by the high resolution scanning tunneling microscopy (STM). The match of peripheral chain length has important influence on the mesomorphism of the binary mixtures. Project supported by the National Natural Science Foundation of China (Grant Nos. 51273133 and 51443004).

A rapid Fourier transform infrared spectroscopic method for analysis of certain proton pump inhibitors in binary and ternary mixtures

NASA Astrophysics Data System (ADS)

Khashaba, Pakinaz Y.; Ali, Hassan Refat H.; El-Wekil, Mohamed M.

2018-02-01

A simple and non-destructive FTIR method was used to determine certain proton pump inhibitors (PPIs) in binary and ternary mixtures. Proton pump inhibitors (PPIs); omeprazole (OMZ), esomeprazole (EZM), lansoprazole (LAN), pantoprazole sodium (PAN sodium) and rabeprazole sodium (RAB sodium) in binary mixture with domperidone (DOM) and ternary mixture of OMZ, clarithromycin (CLM) and tinidazole (TNZ) were determined in the solid-state by FTIR spectroscopy for the first time. The method was validated according to ICH-guidelines where linearity was ranged from 20 to 850 μg/g and 20-360 μg/g for PPIs and DOM, respectively in binary mixtures and 10-400, 100-8000 and 150-14,000 μg/g for OMZ, CLM and TNZ, respectively. Limits of detection were found to be 6-100 and 9-100 μg/g for PPIs and DOM, respectively and 4, 40 and 50 μg/g for OMZ, CLM and TNZ, respectively. The method was applied successfully for determination of the cited drugs in their respective pharmaceutical dosage forms.

The Kirkwood-Buff theory of solutions and the local composition of liquid mixtures.

PubMed

Shulgin, Ivan L; Ruckenstein, Eli

2006-06-29

The present paper is devoted to the local composition of liquid mixtures calculated in the framework of the Kirkwood-Buff theory of solutions. A new method is suggested to calculate the excess (or deficit) number of various molecules around a selected (central) molecule in binary and multicomponent liquid mixtures in terms of measurable macroscopic thermodynamic quantities, such as the derivatives of the chemical potentials with respect to concentrations, the isothermal compressibility, and the partial molar volumes. This method accounts for an inaccessible volume due to the presence of a central molecule and is applied to binary and ternary mixtures. For the ideal binary mixture it is shown that because of the difference in the volumes of the pure components there is an excess (or deficit) number of different molecules around a central molecule. The excess (or deficit) becomes zero when the components of the ideal binary mixture have the same volume. The new method is also applied to methanol + water and 2-propanol + water mixtures. In the case of the 2-propanol + water mixture, the new method, in contrast to the other ones, indicates that clusters dominated by 2-propanol disappear at high alcohol mole fractions, in agreement with experimental observations. Finally, it is shown that the application of the new procedure to the ternary mixture water/protein/cosolvent at infinite dilution of the protein led to almost the same results as the methods involving a reference state.

Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study.

PubMed

Attia, Khalid A M; Nassar, Mohammed W I; El-Zeiny, Mohamed B; Serag, Ahmed

2016-05-15

Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of three veterinary antibiotics and their binary mixtures on two green alga species.

PubMed

Carusso, S; Juárez, A B; Moretton, J; Magdaleno, A

2018-03-01

The individual and combined toxicities of chlortetracycline (CTC), oxytetracycline (OTC) and enrofloxacin (ENF) have been examined in two green algae representative of the freshwater environment, the international standard strain Pseudokichneriella subcapitata and the native strain Ankistrodesmus fusiformis. The toxicities of the three antibiotics and their mixtures were similar in both strains, although low concentrations of ENF and CTC + ENF were more toxic in A. fusiformis than in the standard strain. The toxicological interactions of binary mixtures were predicted using the two classical models of additivity: Concentration Addition (CA) and Independent Action (IA), and compared to the experimentally determined toxicities over a range of concentrations between 0.1 and 10 mg L -1 . The CA model predicted the inhibition of algal growth in the three mixtures in P. subcapitata, and in the CTC + OTC and CTC + ENF mixtures in A. fusiformis. However, this model underestimated the experimental results obtained in the OTC + ENF mixture in A. fusiformis. The IA model did not predict the experimental toxicological effects of the three mixtures in either strain. The sum of the toxic units (TU) for the mixtures was calculated. According to these values, the binary mixtures CTC + ENF and OTC + ENF showed an additive effect, and the CTC + OTC mixture showed antagonism in P. subcapitata, whereas the three mixtures showed synergistic effects in A. fusiformis. Although A. fusiformis was isolated from a polluted river, it showed a similar sensitivity with respect to P. subcapitata when it was exposed to binary mixtures of antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

How Is the Freezing Point of a Binary Mixture of Liquids Related to the Composition? A Guided Inquiry Experiment

ERIC Educational Resources Information Center

Hunnicutt, Sally S.; Grushow, Alexander; Whitnell, Rob

2017-01-01

The principles of process-oriented guided inquiry learning (POGIL) are applied to a binary solid-liquid mixtures experiment. Over the course of two learning cycles, students predict, measure, and model the phase diagram of a mixture of fatty acids. The enthalpy of fusion of each fatty acid is determined from the results. This guided inquiry…

Experimental investigation of thermodynamic properties of binary mixture of acetic acid + n-butanol and acetic acid + water at temperature from 293.15 K to 343.15 K

NASA Astrophysics Data System (ADS)

Paul, M. Danish John; Shruthi, N.; Anantharaj, R.

2018-04-01

The derived thermodynamic properties like excess molar volume, partial molar volume, excess partial molar volume and apparent volume of binary mixture of acetic acid + n-butanolandacetic acid + water has been investigated using measured density of mixtures at temperatures from 293.15 K to 343.15.

Getting More Ecologically Relevant Information from Laboratory Tests: Recovery of Lemna minor After Exposure to Herbicides and Their Mixtures.

PubMed

Knežević, Varja; Tunić, Tanja; Gajić, Pero; Marjan, Patricija; Savić, Danko; Tenji, Dina; Teodorović, Ivana

2016-11-01

Recovery after exposure to herbicides-atrazine, isoproturon, and trifluralin-their binary and ternary mixtures, was studied under laboratory conditions using a slightly adapted standard protocol for Lemna minor. The objectives of the present study were (1) to compare empirical to predicted toxicity of selected herbicide mixtures; (2) to assess L. minor recovery potential after exposure to selected individual herbicides and their mixtures; and (3) to suggest an appropriate recovery potential assessment approach and endpoint in a modified laboratory growth inhibition test. The deviation of empirical from predicted toxicity was highest in binary mixtures of dissimilarly acting herbicides. The concentration addition model slightly underestimated mixture effects, indicating potential synergistic interactions between photosynthetic inhibitors (atrazine and isoproturon) and a cell mitosis inhibitor (trifluralin). Recovery after exposure to the binary mixture of atrazine and isoproturon was fast and concentration-independent: no significant differences between relative growth rates (RGRs) in any of the mixtures (IC10 Mix , 25 Mix , and 50 Mix ) versus control level were recorded in the last interval of the recovery phase. The recovery of the plants exposed to binary and ternary mixtures of dissimilarly acting herbicides was strictly concentration-dependent. Only plants exposed to IC10 Mix , regardless of the herbicides, recovered RGRs close to control level in the last interval of the recovery phase. The inhibition of the RGRs in the last interval of the recovery phase compared with the control level is a proposed endpoint that could inform on reversibility of the effects and indicate possible mixture effects on plant population recovery potential.

Viscosity of nonelectrolyte liquid mixtures. IV. Binary mixtures containing p-Dioxane

NASA Astrophysics Data System (ADS)

Oswal, S. L.; Oswal, P.; Phalak, R. P.

1996-11-01

Measurements of the viscosity η and density p are reported for eight binary mixtures of p-dioxane with methylcyclohexane, l-chlorohexane, l-bromohexane, p-xylene, propylbenzene, methyl acetate, butyl acetate. anyl acetate at 303.15 K. The viscosity data haw been correlated with the equations of Grunbeng Nissan. of McAllister, and of Auslaendcr. The relation among the excess viscosity Δ In η, excess Gibbs energy of activation ΔG* E of viscous flow. and intermolecular interaction in these mixtures is discussed.

Individual and combined in vitro (anti)androgenic effects of certain food additives and cosmetic preservatives.

PubMed

Pop, Anca; Drugan, Tudor; Gutleb, Arno C; Lupu, Diana; Cherfan, Julien; Loghin, Felicia; Kiss, Béla

2016-04-01

The individual and combined (binary mixtures) (anti)androgenic effect of butylparaben (BuPB), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and propyl gallate (PG) was evaluated using the MDA-kb2 cell line. Exposing these cells to AR agonists results in the expression of the reporter gene (encoding for luciferase) and luminescence can be measured in order to monitor the activity of the reporter protein. In case of the evaluation of the anti-androgenic effect, the individual test compounds or binary mixtures were tested in the presence of a fixed concentration of a strong AR agonist (1000 pM 5-alpha-dihydrotestosterone; DHT). Cell viability was assessed using a resazurin based assay. For PG, this is the first report in the literature concerning its (anti)androgenic activity. In case of both individual and mixture testing none of the compounds or binary combinations showed androgenic activity. When tested in the presence of DHT, BuPB, BHA and BHT proved to be weak anti-androgens and this was confirmed during the evaluation of binary mixtures (BuPB+BHA, BuPB+BHT and BHA+BHT). Besides performing the in vitro testing of the binary combinations, two mathematical models (dose addition and response addition) were evaluated in terms of accuracy of prediction of the anti-androgenic effect of the selected binary mixtures. The dose addition model guaranteed a good correlation between the experimental and predicted data. However, no estimation was possible in case of mixtures containing PG, due to the lack of effect of the compound in case of the individual testing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Solubility modeling of refrigerant/lubricant mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michels, H.H.; Sienel, T.H.

1996-12-31

A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs wheremore » structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations yield more reliable predictions for HFC/POE mixtures.« less

Evaluation of Thermodynamic Models for Predicting Phase Equilibria of CO2 + Impurity Binary Mixture

NASA Astrophysics Data System (ADS)

Shin, Byeong Soo; Rho, Won Gu; You, Seong-Sik; Kang, Jeong Won; Lee, Chul Soo

2018-03-01

For the design and operation of CO2 capture and storage (CCS) processes, equation of state (EoS) models are used for phase equilibrium calculations. Reliability of an EoS model plays a crucial role, and many variations of EoS models have been reported and continue to be published. The prediction of phase equilibria for CO2 mixtures containing SO2, N2, NO, H2, O2, CH4, H2S, Ar, and H2O is important for CO2 transportation because the captured gas normally contains small amounts of impurities even though it is purified in advance. For the design of pipelines in deep sea or arctic conditions, flow assurance and safety are considered priority issues, and highly reliable calculations are required. In this work, predictive Soave-Redlich-Kwong, cubic plus association, Groupe Européen de Recherches Gazières (GERG-2008), perturbed-chain statistical associating fluid theory, and non-random lattice fluids hydrogen bond EoS models were compared regarding performance in calculating phase equilibria of CO2-impurity binary mixtures and with the collected literature data. No single EoS could cover the entire range of systems considered in this study. Weaknesses and strong points of each EoS model were analyzed, and recommendations are given as guidelines for safe design and operation of CCS processes.

Application of wavelet and Fuorier transforms as powerful alternatives for derivative spectrophotometry in analysis of binary mixtures: A comparative study

NASA Astrophysics Data System (ADS)

Hassan, Said A.; Abdel-Gawad, Sherif A.

2018-02-01

Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits.

Temperature Dependence of Densities and Excess Molar Volumes of the Ternary Mixture (1-Butanol + Chloroform + Benzene) and its Binary Constituents (1-Butanol + Chloroform and 1-Butanol + Benzene)

NASA Astrophysics Data System (ADS)

Smiljanić, Jelena D.; Kijevčanin, Mirjana Lj.; Djordjević, Bojan D.; Grozdanić, Dušan K.; Šerbanović, Slobodan P.

2008-04-01

Densities ρ of the 1-butanol + chloroform + benzene ternary mixture and the 1-butanol + chloroform and 1-butanol + benzene binaries have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure, using an oscillating U-tube densimeter. From these densities, excess molar volumes ( V E) were calculated and fitted to the Redlich Kister equation for all binary mixtures and to the Nagata and Tamura equation for the ternary system. The Radojković et al. equation has been used to predict excess molar volumes of the ternary mixtures. Also, V E data of the binary systems were correlated by the van der Waals (vdW1) and Twu Coon Bluck Tilton (TCBT) mixing rules coupled with the Peng Robinson Stryjek Vera (PRSV) equation of state. The prediction and correlation of V E data for the ternary system were performed by the same models.

Detailed Investigation of Separation Performance of a MMM for Removal of Higher Hydrocarbons under Varying Operating Conditions

PubMed Central

Mushardt, Heike; Müller, Marcus; Shishatskiy, Sergey; Wind, Jan; Brinkmann, Torsten

2016-01-01

Mixed-matrix membranes (MMMs) are promising candidates to improve the competitiveness of membrane technology against energy-intensive conventional technologies. In this work, MMM composed of poly(octylmethylsiloxane) (POMS) and activated carbon (AC) were investigated with respect to separation of higher hydrocarbons (C3+) from permanent gas streams. Membranes were prepared as thin film composite membranes on a technical scale and characterized via scanning electron microscopy (SEM) and permeation measurements with binary mixtures of n-C4H10/CH4 under varying operating conditions (feed and permeate pressure, temperature, feed gas composition) to study the influence on separation performance. SEM showed good contact and absence of defects. Lower permeances but higher selectivities were found for MMM compared to pure POMS membrane. Best results were obtained at high average fugacity and activity of n-C4H10 with the highest selectivity estimated to be 36.4 at n-C4H10 permeance of 12 mN3/(m2·h·bar). Results were complemented by permeation of a multi-component mixture resembling a natural gas application, demonstrating the superior performance of MMM. PMID:26927194

Alternative process schemes for coal conversion. Progress report No. 1, October 1, 1978--January 31, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sansone, M.J.

1979-02-01

On the basis of simple, first approximation calculations, it has been shown that catalytic gasification and hydrogasification are inherently superior to conventional gasification with respect to carbon utilization and thermal efficiency. However, most processes which are directed toward the production of substitute natural gas (SNG) by direct combination of coal with steam at low temperatures (catalytic processes) or with hydrogen (hydrogasification) will require a step for separation of product SNG from a recycle stream. The success or falure of the process could well depend upon the economics of this separation scheme. The energetics for the separation of mixtures of idealmore » gases has been considered in some detail. Minimum energies for complete separation of representative effluent mixtures have been calculated as well as energies for separation into product and recycle streams. The gas mixtures include binary systems of H/sub 2/ and CH/sub 4/ and ternary mixtures of H/sub 2/, CH/sub 4/, and CO. A brief summary of a number of different real separation schemes has also been included. We have arbitrarily divided these into five categories: liquefaction, absorption, adsorption, chemical, and diffusional methods. These separation methods will be screened and the more promising methods examined in more detail in later reports. Finally, a brief mention of alternative coal conversion processes concludes this report.« less

Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

NASA Astrophysics Data System (ADS)

Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

2013-12-01

Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

Study of thermodynamic and acoustic behaviour of nicotinic acid in binary aqueous mixtures of D-lactose

NASA Astrophysics Data System (ADS)

Sharma, Ravi; Thakur, R. C.

2017-07-01

In the present study, the thermodynamic properties such as partial molar volumes, partial molar expansibilities, partial molar compressibilities, partial molar heat capacities and isobaric thermal expansion coefficient of different solutions of nicotinic acid in binary aqueous mixtures of D-lactose have been determined at different temperatures (298.15, 303.15, 308.15, 313.15) K. Masson's equation is used to interpret the data in terms of solute-solute and solute-solvent interactions. In the present study it has been found that nicotinic acid behaves as structure maker in aqueous and binary aqueous mixtures of D-lactose.

Phase behaviour, interactions, and structural studies of (amines+ionic liquids) binary mixtures.

PubMed

Jacquemin, Johan; Bendová, Magdalena; Sedláková, Zuzana; Blesic, Marijana; Holbrey, John D; Mullan, Claire L; Youngs, Tristan G A; Pison, Laure; Wagner, Zdeněk; Aim, Karel; Costa Gomes, Margarida F; Hardacre, Christopher

2012-05-14

We present a study on the phase equilibrium behaviour of binary mixtures containing two 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids, [C(n)mim] [NTf(2)] (n=2 and 4), mixed with diethylamine or triethylamine as a function of temperature and composition using different experimental techniques. Based on this work, two systems showing an LCST and one system with a possible hourglass shape are measured. Their phase behaviours are then correlated and predicted by using Flory-Huggins equations and the UNIQUAC method implemented in Aspen. The potential of the COSMO-RS methodology to predict the phase equilibria was also tested for the binary systems studied. However, this methodology is unable to predict the trends obtained experimentally, limiting its use for systems involving amines in ionic liquids. The liquid-state structure of the binary mixture ([C(2)mim] [NTf(2)]+diethylamine) is also investigated by molecular dynamics simulation and neutron diffraction. Finally, the absorption of gaseous ethane by the ([C(2)mim][NTf(2)]+diethylamine) binary mixture is determined and compared with that observed in the pure solvents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical analysis for condensation heat transfer of binary refrigerant mixtures with annular flow in horizontal mini-tubes

NASA Astrophysics Data System (ADS)

Zhang, Hui-Yong; Li, Jun-Ming; Sun, Ji-Liang; Wang, Bu-Xuan

2016-01-01

A theoretical model is developed for condensation heat transfer of binary refrigerant mixtures in mini-tubes with diameter about 1.0 mm. Condensation heat transfer of R410A and R32/R134a mixtures at different mass fluxes and saturated temperatures are analyzed, assuming that the phase flow pattern is annular flow. The results indicate that there exists a maximum interface temperature at the beginning of condensation process for azeotropic and zeotropic mixtures and the corresponding vapor quality to the maximum value increases with mass flux. The effects of mass flux, heat flux, surface tension and tube diameter are analyzed. As expected, the condensation heat transfer coefficients increase with mass flux and vapor quality, and increase faster in high vapor quality region. It is found that the effects of heat flux and surface tension are not so obvious as that of tube diameter. The characteristics of condensation heat transfer of zeotropic mixtures are consistent to those of azeotropic refrigerant mixtures. The condensation heat transfer coefficients increase with the concentration of the less volatile component in binary mixtures.

NEUROBEHAVIORAL EVALUATIONS OF BINARY AND TERTIARY MIXTURES OF CHEMICALS: LESSIONS LEARNING.

EPA Science Inventory

The classical approach to the statistical analysis of binary chemical mixtures is to construct full dose-response curves for one compound in the presence of a range of doses of the second compound (isobolographic analyses). For interaction studies using more than two chemicals, ...

Monitoring the Gas Composition of the NIFFTE Time Projection Chamber

NASA Astrophysics Data System (ADS)

Towell, Travis; Travis Towell Collaboration

2017-09-01

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) at Los Alamos National Laboratory(LANL) is using a Time Projection Chamber (TPC) to measure with high precision the cross section ratio of U238 to P239. When the neutron beam hits a target, it may emit fission fragments. As the fission fragments travels through the chamber, it ionizes the gas it passes through. Based on the time it takes for the ions to drift to the pad planes and the hit location of the ions, the path of fission fragments can be determined. Knowing the composition of the gas mixture is vital to accurately reconstruct the data. A Binary Gas Analyzer (BGA) is used to measure the gas composition. To confirm the accuracy of the BGA, varying amounts of nitrogen and carbon dioxide were flowed through a test gas system. Several tests were performed to validate that the BGA for our gas system is working properly. This poster will describe the test gas system setup, tests of the BGA, and elaborate on the main goals of the NIFFTE experiment.

Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

PubMed

Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

2010-09-17

In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of binary mixtures of zinc, copper, cadmium, and nickel on the growth of the freshwater diatom Navicula pelliculosa and comparison with mixture toxicity model predictions.

PubMed

Nagai, Takashi; De Schamphelaere, Karel A C

2016-11-01

The authors investigated the effect of binary mixtures of zinc (Zn), copper (Cu), cadmium (Cd), and nickel (Ni) on the growth of a freshwater diatom, Navicula pelliculosa. A 7 × 7 full factorial experimental design (49 combinations in total) was used to test each binary metal mixture. A 3-d fluorescence microplate toxicity assay was used to test each combination. Mixture effects were predicted by concentration addition and independent action models based on a single-metal concentration-response relationship between the relative growth rate and the calculated free metal ion activity. Although the concentration addition model predicted the observed mixture toxicity significantly better than the independent action model for the Zn-Cu mixture, the independent action model predicted the observed mixture toxicity significantly better than the concentration addition model for the Cd-Zn, Cd-Ni, and Cd-Cu mixtures. For the Zn-Ni and Cu-Ni mixtures, it was unclear which of the 2 models was better. Statistical analysis concerning antagonistic/synergistic interactions showed that the concentration addition model is generally conservative (with the Zn-Ni mixture being the sole exception), indicating that the concentration addition model would be useful as a method for a conservative first-tier screening-level risk analysis of metal mixtures. Environ Toxicol Chem 2016;35:2765-2773. © 2016 SETAC. © 2016 SETAC.

Xenon and Other Volatile Anesthetics Change Domain Structure in Model Lipid Raft Membranes

PubMed Central

Weinrich, Michael; Worcester, David L.

2014-01-01

Inhalation anesthetics have been in clinical use for over 160 years, but the molecular mechanisms of action continue to be investigated. Direct interactions with ion channels received much attention after it was found that anesthetics do not change the structure of homogeneous model membranes. However, it was recently found that halothane, a prototypical anesthetic, changes domain structure of a binary lipid membrane. The noble gas xenon is an excellent anesthetic and provides a pivotal test of the generality of this finding, extended to ternary lipid raft mixtures. We report that xenon and conventional anesthetics change the domain equilibrium in two canonical ternary lipid raft mixtures. These findings demonstrate a membrane-mediated mechanism whereby inhalation anesthetics can affect the lipid environment of trans-membrane proteins. PMID:24299622

Vaporization thermodynamic studies by high-temperature mass spectrometry on some three-phase regions over the MnO-TeO2 binary line in the Mn-Te-O ternary system.

PubMed

Narasimhan, T S Lakshmi; Sai Baba, M; Viswanathan, R

2006-12-28

Knudsen effusion mass spectrometric measurements have been performed in the temperature range of 850-950 K over four three-phase mixtures, each phase mixture having at least one phase lying on the MnO-TeO2 binary line of the Mn-Te-O phase diagram, and the rest of the phases lying above this binary line. The three-phase mixtures investigated are Mn3O4 + MnO + Mn6Te5O16; Mn3O4 + Mn6Te5O16 + MnTeO3; Mn3O4 + Mn3TeO6 + MnTeO3; and Mn3TeO6 + MnTeO3 + Mn2Te3O8. The vapor pressures of the gaseous species TeO2, TeO, and Te2 over these three-phase mixtures were measured, and various heterogeneous solid-gas reactions were evaluated along with the homogeneous gas-phase reaction TeO2(g) + 0.5Te2(g) = 2 TeO(g). The enthalpy and Gibbs free energy of formation of the four ternary Mn-Te-O phases were deduced at T = 900 K. These values (in kJ.mol-1), along with the estimated uncertainties in them are Delta(f)H(o)m = 4150 +/- 19, 752 +/- 11, 1710 +/- 11, 1924 +/- 40, and Delta(f)G(o)m= 2835 +/- 28, 511 +/- 11, 1254 +/- 19, 1238 +/- 38, for Mn6Te5O16, MnTeO3, Mn3TeO6, and Mn2Te3O8, respectively. A thermochemical assessment was made to examine the conditions under which the ternary Mn-Te-O phases could be formed on a stainless steel clad of mixed-oxide-fueled (MO2; M = U + Pu) fast breeder nuclear reactors. The phase Mn3TeO6 could be formed when the fuel is even slightly hyperstoichiometric (O/M = 2.0002) and the phase Mn6Te5O16 could also be formed when O/M = 2.0004. The threshold tellurium potential for the formation of Mn3TeO6 is higher than that for MnTe0.80 and CrTe1.10, but is comparable to that for MoTe1.10, and even lower than that for FeTe0.81 or NiTe0.63.

Study of thermodynamic and transport properties of binary liquid mixture of diesel with biodiesel at 298.15K

NASA Astrophysics Data System (ADS)

Suthar, Shyam Sunder; Purohit, Suresh

2018-05-01

Properties of diesel and biodiesel (produced from corn oil) are used. Densities and viscosities of binary mixture of diesel with biodiesel (produced from corn oil) have been computed by using liquid binary mixture law over the entire range of compositions at T=298.15K and atmospheric pressure. From the computed values of density and viscosities, viscosity deviation (Δη), the excess molar volume (VE) and excess Gibbs energy of activation of viscous flow (ΔG#E) have been calculated. The results of excess volume, excess Gibbs energy of activation of viscous flow and viscosity deviation have been fitted to Redlich -Kister models to estimate the binary coefficients. The results are communicated in terms of the molecular interactions and the best suited composition has been found.

Binary Mixtures of Permanganate and Chlorinated Volatile Organic Compounds in Groundwater Samples: Sample Preservation and Analysis

EPA Science Inventory

Ground water samples collected at sites where in-situ chemical oxidation (ISCO) has been deployed may contain binary mixtures of ground water contaminants and permanganate (MnO4-), an oxidant injected into the subsurface to destroy the contaminant. Commingling of the oxidant and ...

Seasonal nitrogen effects on nutritive value in binary mixtures of tall fescue and bermudagrass

USDA-ARS?s Scientific Manuscript database

Year-round forage production is feasible in much of the southeastern USA through utilization of cool- and warm-season forages. This study determined changes in herbage nutritive value in binary mixtures of cool-season, tall fescue [Schedonorus arundinaceus (Schreb.) Dumort], and warm-season, bermuda...

Thermal characteristics of oleochemical carbonate binary mixtures for potential latent heat storage

USDA-ARS?s Scientific Manuscript database

The present study examines the thermal properties of melting and solidification for binary mixtures between dodecyl carbonate (1a), tetradecyl carbonate (1b), hexadecyl carbonate (1c), and octadecyl carbonate (1d) by differential scanning calorimetry (DSC) in order to gain further understanding of t...

Establishment and yield of perennial grass monocultures and binary mixtures for bioenergy in North Dakota

USDA-ARS?s Scientific Manuscript database

To develop appropriate bioenergy production systems to match site-specific situations, establishment and yield were evaluated for switchgrass, intermediate wheatgrass, tall wheatgrass, and three binary mixtures at four sites in North Dakota from 2006 to 2011. Canopy cover at harvest for intermediat...

Cultivar x binary mixture interaction effect on agronomic traits in orchardgrass

USDA-ARS?s Scientific Manuscript database

A study was conducted to evaluate and characterize the agronomic value, including dry matter yield and forage quality of 25 orchardgrass cultivars grown in monoculture and binary mixtures with alfalfa under supplemental irrigation from 2009 to 2012 at a Millville, UT, field site. Orchardgrass monoc...

The contribution of molecular relaxation in nitrogen to the absorption of sound in the atmosphere

NASA Technical Reports Server (NTRS)

Zuckerwar, A. J.; Meredith, R. W.

1980-01-01

Results and statistical analysis are presented for sound absorption in N2-H2O binary mixtures at room temperature. Experimental procedure, temperature effects, and preliminary results are presented for sound absorption in N2-H2O binary mixtures at elevated temperatures.

A quick responding quartz crystal microbalance sensor array based on molecular imprinted polyacrylic acids coating for selective identification of aldehydes in body odor.

PubMed

Jha, Sunil K; Hayashi, Kenshi

2015-03-01

In present work, a novel quartz crystal microbalance (QCM) sensor array has been developed for prompt identification of primary aldehydes in human body odor. Molecularly imprinted polymers (MIP) are prepared using the polyacrylic acid (PAA) polymer matrix and three organic acids (propenoic acid, hexanoic acid and octanoic acid) as template molecules, and utilized as QCM surface coating layer. The performance of MIP films is characterized by 4-element QCM sensor array (three coated with MIP layers and one with pure PAA for reference) dynamic and static responses to target aldehydes: hexanal, heptanal, and nonanal in single, binary, and tertiary mixtures at distinct concentrations. The target aldehydes were selected subsequent to characterization of body odor samples with solid phase-micro extraction gas chromatography mass spectrometer (SPME-GC-MS). The hexanoic acid and octanoic acid imprinted PAA exhibit fast response, and better sensitivity, selectivity and reproducibility than the propenoic acid, and non-imprinted PAA in array. The response time and recovery time for hexanoic acid imprinted PAA are obtained as 5 s and 12 s respectively to typical concentrations of binary and tertiary mixtures of aldehydes using the static response. Dynamic sensor array response matrix has been processed with principal component analysis (PCA) for visual, and support vector machine (SVM) classifier for quantitative identification of target odors. Aldehyde odors were identified successfully in principal component (PC) space. SVM classifier results maximum recognition rate 79% for three classes of binary odors and 83% including single, binary, and tertiary odor classes in 3-fold cross validation. Copyright © 2014 Elsevier B.V. All rights reserved.

Excess Volumes and Excess Isentropic Compressibilities of Binary Liquid Mixtures of Trichloroethylene with Esters at 303.15 K

NASA Astrophysics Data System (ADS)

Ramanaiah, S.; Rao, C. Narasimha; Nagaraja, P.; Venkateswarlu, P.

2015-11-01

Exces volumes, VE, and excess isentropic compressibilities, κSE, have been reported as a function of composition for binary liquid mixtures of trichloroethylene with ethyl acetate, n-propyl acetate, and n-butyl acetate at 303.15 K. Isentropic compressibilities are calculated using measured sound speeds and density data for pure components and for binary mixtures. Excess volumes and excess isentropic compressibilities are found to be negative for the three systems studied over the entire composition range at 303.15 K, whereas these values become more negative with an increase of carbon chain length. The results are discussed in terms of intermolecular interactions between unlike molecules.

Odor detection of mixtures of homologous carboxylic acids and coffee aroma compounds by humans.

PubMed

Miyazawa, Toshio; Gallagher, Michele; Preti, George; Wise, Paul M

2009-11-11

Mixture summation among homologous carboxylic acids, that is, the relationship between detection probabilities for mixtures and detection probabilities for their unmixed components, varies with similarity in carbon-chain length. The current study examined detection of acetic, butyric, hexanoic, and octanoic acids mixed with three other model odorants that differ greatly from the acids in both structure and odor character, namely, 2-hydroxy-3-methylcyclopent-2-en-1-one, furan-2-ylmethanethiol, and (3-methyl-3-sulfanylbutyl) acetate. Psychometric functions were measured for both single compounds and binary mixtures (2 of 5, forced-choice method). An air dilution olfactometer delivered stimuli, with vapor-phase calibration using gas chromatography-mass spectrometry. Across the three odorants that differed from the acids, acetic and butyric acid showed approximately additive (or perhaps even supra-additive) summation at low perithreshold concentrations, but subadditive interactions at high perithreshold concentrations. In contrast, the medium-chain acids showed subadditive interactions across a wide range of concentrations. Thus, carbon-chain length appears to influence not only summation with other carboxylic acids but also summation with at least some unrelated compounds.

Fine-tuning molecular acoustic models: sensitivity of the predicted attenuation to the Lennard-Jones parameters

NASA Astrophysics Data System (ADS)

Petculescu, Andi G.; Lueptow, Richard M.

2005-01-01

In a previous paper [Y. Dain and R. M. Lueptow, J. Acoust. Soc. Am. 109, 1955 (2001)], a model of acoustic attenuation due to vibration-translation and vibration-vibration relaxation in multiple polyatomic gas mixtures was developed. In this paper, the model is improved by treating binary molecular collisions via fully pairwise vibrational transition probabilities. The sensitivity of the model to small variations in the Lennard-Jones parameters-collision diameter (σ) and potential depth (ɛ)-is investigated for nitrogen-water-methane mixtures. For a N2(98.97%)-H2O(338 ppm)-CH4(1%) test mixture, the transition probabilities and acoustic absorption curves are much more sensitive to σ than they are to ɛ. Additionally, when the 1% methane is replaced by nitrogen, the resulting mixture [N2(99.97%)-H2O(338 ppm)] becomes considerably more sensitive to changes of σwater. The current model minimizes the underprediction of the acoustic absorption peak magnitudes reported by S. G. Ejakov et al. [J. Acoust. Soc. Am. 113, 1871 (2003)]. .

Studies in Three Phase Gas-Liquid Fluidised Systems

NASA Astrophysics Data System (ADS)

Awofisayo, Joyce Ololade

1992-01-01

Available from UMI in association with The British Library. The work is a logical continuation of research started at Aston some years ago when studies were conducted on fermentations in bubble columns. The present work highlights typical design and operating problems that could arise in such systems as waste water, chemical, biochemical and petroleum operations involving three-phase, gas-liquid -solid fluidisation; such systems are in increasing use. It is believed that this is one of few studies concerned with "true" three-phase, gas-liquid-solid fluidised systems, and that this work will contribute significantly to closing some of the gaps in knowledge in this area. The research work was experimentally based and involved studies of the hydrodynamic parameters, phase holdups (gas and solid), particle mixing and segregation, and phase flow dynamics (flow regime and circulation patterns). The studies have focused particularly on the solid behaviour and the influence of properties of solids present on the above parameters in three-phase, gas-liquid-solid fluidised systems containing single particle components and those containing binary and ternary mixtures of particles. All particles were near spherical in shape and two particle sizes and total concentration levels were used. Experiments were carried out in two- and three-dimensional bubble columns. Quantitative results are presented in graphical form and are supported by qualitative results from visual studies which are also shown as schematic diagrams and in photographic form. Gas and solid holdup results are compared for air-water containing single, binary and ternary component particle mixtures. It should be noted that the criteria for selection of the materials used are very important if true three-phase fluidisation is to be achieved: this is very evident when comparing the results with those in the literature. The fluid flow and circulation patterns observed were assessed for validation of the generally accepted patterns, and the author believes that the present work provides more accurate insight into the modelling of liquid circulation in bubble columns. The characteristic bubbly flow at low gas velocity in a two-phase system is suppressed in the three-phase system. The degree of mixing within the system is found to be dependent on flow regime, liquid circulation and the ratio of solid phase physical properties.

Induced smectic phase in binary mixtures of twist-bend nematogens.

PubMed

Knežević, Anamarija; Dokli, Irena; Sapunar, Marin; Šegota, Suzana; Baumeister, Ute; Lesac, Andreja

2018-01-01

The investigation of liquid crystal (LC) mixtures is of great interest in tailoring material properties for specific applications. The recent discovery of the twist-bend nematic phase (N TB ) has sparked great interest in the scientific community, not only from a fundamental viewpoint, but also due to its potential for innovative applications. Here we report on the unexpected phase behaviour of a binary mixture of twist-bend nematogens. A binary phase diagram for mixtures of imino-linked cyanobiphenyl (CBI) dimer and imino-linked benzoyloxy-benzylidene (BB) dimer shows two distinct domains. While mixtures containing less than 35 mol % of BB possess a wide temperature range twist-bend nematic phase, the mixtures containing 55-80 mol % of BB exhibit a smectic phase despite that both pure compounds display a Iso-N-N TB -Cr phase sequence. The phase diagram shows that the addition of BB of up to 30 mol % significantly extends the temperature range of the N TB phase, maintaining the temperature range of the nematic phase. The periodicity, obtained by atomic force microscopy (AFM) imaging, is in the range of 6-7 nm. The induction of the smectic phase in the mixtures containing 55-80 mol % of BB was confirmed using polarising optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction. The origin of the intercalated smectic phase was unravelled by combined spectroscopic and computational methods and can be traced to conformational disorder of the terminal chains. These results show the importance of understanding the phase behaviour of binary mixtures, not only in targeting a wide temperature range but also in controlling the self-organizing processes.

Herbage nutritive value of tall fescue-bermudagrass binary mixtures fertilized with combinations of nitrogen fertilizer and poultry litter

USDA-ARS?s Scientific Manuscript database

Year-round forage production is feasible in much of the southeastern USA through utilization of cool- and warm-season forages. This study determined if productivity and nutritive value in binary mixtures of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] and bermudagrass [Cynodon dactylon (L...

ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES

EPA Science Inventory

Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

Stability of fluctuating and transient aggregates of amphiphilic solutes in aqueous binary mixtures: Studies of dimethylsulfoxide, ethanol, and tert-butyl alcohol

NASA Astrophysics Data System (ADS)

Banerjee, Saikat; Bagchi, Biman

2013-10-01

In aqueous binary mixtures, amphiphilic solutes such as dimethylsulfoxide (DMSO), ethanol, tert-butyl alcohol (TBA), etc., are known to form aggregates (or large clusters) at small to intermediate solute concentrations. These aggregates are transient in nature. Although the system remains homogeneous on macroscopic length and time scales, the microheterogeneous aggregation may profoundly affect the properties of the mixture in several distinct ways, particularly if the survival times of the aggregates are longer than density relaxation times of the binary liquid. Here we propose a theoretical scheme to quantify the lifetime and thus the stability of these microheterogeneous clusters, and apply the scheme to calculate the same for water-ethanol, water-DMSO, and water-TBA mixtures. We show that the lifetime of these clusters can range from less than a picosecond (ps) for ethanol clusters to few tens of ps for DMSO and TBA clusters. This helps explaining the absence of a strong composition dependent anomaly in water-ethanol mixtures but the presence of the same in water-DMSO and water-TBA mixtures.

Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study.

PubMed

Elzanfaly, Eman S; Hassan, Said A; Salem, Maissa Y; El-Zeany, Badr A

2015-12-05

A comparative study was established between two signal processing techniques showing the theoretical algorithm for each method and making a comparison between them to indicate the advantages and limitations. The methods under study are Numerical Differentiation (ND) and Continuous Wavelet Transform (CWT). These methods were studied as spectrophotometric resolution tools for simultaneous analysis of binary and ternary mixtures. To present the comparison, the two methods were applied for the resolution of Bisoprolol (BIS) and Hydrochlorothiazide (HCT) in their binary mixture and for the analysis of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) as an example for ternary mixtures. By comparing the results in laboratory prepared mixtures, it was proven that CWT technique is more efficient and advantageous in analysis of mixtures with severe overlapped spectra than ND. The CWT was applied for quantitative determination of the drugs in their pharmaceutical formulations and validated according to the ICH guidelines where accuracy, precision, repeatability and robustness were found to be within the acceptable limit. Copyright © 2015 Elsevier B.V. All rights reserved.

Simple views on critical binary liquid mixtures in porous glass

NASA Astrophysics Data System (ADS)

Tremblay, L.; Socol, S. M.; Lacelle, S.

2000-01-01

A simple scenario, different from previous attempts, is proposed to resolve the problem of the slow phase separation dynamics of binary liquid mixtures confined in porous Vycor glass. We demonstrate that simply mutual diffusion, renormalized by critical composition fluctuations and geometrical hindrance of the porous glass, accounts for the slow phase separation kinetics. Capillary invasion studies of porous Vycor glass by the critical isobutyric acid-water mixture, close to the consolute solution temperature, corroborate our analysis.

Less common applications of simulated moving bed chromatography in the pharmaceutical industry.

PubMed

Huthmann, E; Juza, M

2005-10-21

Simulated moving bed (SMB) chromatography is often perceived in the pharmaceutical industry as chromatographic method for separating binary mixtures, like racemates. However, SMB can also be used for unbalanced separations, i.e. binary mixtures of varying compositions and multi-component mixtures. These less common application modes of isocratic SMB chromatography are exemplified for four different compounds (racemates and diastereomers) and discussed in view of the so-called 'triangle theory' from an industrial perspective.

Flash-point prediction for binary partially miscible mixtures of flammable solvents.

PubMed

Liaw, Horng-Jang; Lu, Wen-Hung; Gerbaud, Vincent; Chen, Chan-Cheng

2008-05-30

Flash point is the most important variable used to characterize fire and explosion hazard of liquids. Herein, partially miscible mixtures are presented within the context of liquid-liquid extraction processes. This paper describes development of a model for predicting the flash point of binary partially miscible mixtures of flammable solvents. To confirm the predictive efficacy of the derived flash points, the model was verified by comparing the predicted values with the experimental data for the studied mixtures: methanol+octane; methanol+decane; acetone+decane; methanol+2,2,4-trimethylpentane; and, ethanol+tetradecane. Our results reveal that immiscibility in the two liquid phases should not be ignored in the prediction of flash point. Overall, the predictive results of this proposed model describe the experimental data well. Based on this evidence, therefore, it appears reasonable to suggest potential application for our model in assessment of fire and explosion hazards, and development of inherently safer designs for chemical processes containing binary partially miscible mixtures of flammable solvents.

High-pressure sorption of nitrogen, carbon dioxide, and their mixtures on Argonne Premium Coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreas Busch; Yves Gensterblum; Bernhard M. Krooss

2007-06-15

Gas sorption isotherms have been measured for carbon dioxide and nitrogen and their binary mixture (N{sub 2}/CO{sub 2} {approximately} 80/20) on three different moisture-equilibrated coals from the Argonne Premium Coal Sample Program by the U.S. Department of Energy, varying in rank from 0.25 to 1.68% vitrinite reflectance (VR{sub r}). The measurements were conducted at 55 C and at pressures up to 27 MPa for the pure gases and up to 10 MPa for the gas mixture. The effects of the large differences in equilibrium moisture contents (0.8 to 32.2%) on sorption capacity were estimated on the basis of the aqueousmore » solubility of CO{sub 2} and N{sub 2} at experimental conditions. Especially for the Beulah-Zap coal with an equilibrium moisture content of {approximately} 32%, the amount of dissolved CO{sub 2} contributes significantly to the overall storage capacity, whereas the amounts of N{sub 2} dissolved in the moisture water are low and can be neglected. Sorption measurements with nitrogen/carbon dioxide mixtures showed very low capacities for N{sub 2}. For Illinois coal, these excess sorption values were even slightly negative, probably due to small volumetric effects (changes in condensed phase volume). The evolution of the composition of the free gas phase in contact with the coal sample has been monitored continuously during each pressure step of the sorption tests. This composition changed strongly over time. Apparently, CO{sub 2} reaches sorption sites very quickly initially and is subsequently partly replaced by N{sub 2} molecules until concentration equilibration is reached. 18 refs., 10 figs., 2 tabs.« less

Preferential solvation bromophenol blue in water-alcohol binary mixture.

PubMed

Dangui, Anayana Z; Santos, Vanessa M S; Gomes, Benhur S; de Castilho, Taiane S; Nicolini, Keller P; Nicolini, Jaqueline

2018-05-29

In this study, the perichromic behavior of bromophenol blue (BPB) in various binary solvent mixtures was investigated. The binary mixtures considered were comprised of water and methanol (MeOH), ethanol (EtOH), n-propanol (n-PrOH), isopropanol (iso-PrOH) or t-butanol (t-BuOH). The investigation of a preferential solvation model that considers the addition of small quantities of alcohol to water in the presence of bromophenol blue (BPB) is described in this paper. The data obtained were employed to study the preferential solvation (PS) of the probe. It was observed that with increases in the molar fraction of water the spontaneity of the system decreases. This can be explained by the high solubility of BPB in ethanol, with ∆G>0 at higher wavelengths (region rich in water with violet solution) and ∆G<0 at lower wavelengths (region rich in alcohol with yellow solution). The pK of the binary mixture changed in all solvents and for all ratios, and the higher the water ratio is the lower the pK In will be. In binary mixture, an increase in the hydrogen bond acceptor (HBA) nature of the solvents tested resulted in a bathochromic effect on the absorption band of BPB (Δλ=12nm). All of the data obtained showed a good nonlinear fit with the mathematical model (SD≤6.6×10 -3 ), suggesting that BPB has other potential applications besides its use as a pH indicator. Copyright © 2017. Published by Elsevier B.V.

Detection of cocrystal formation based on binary phase diagrams using thermal analysis.

PubMed

Yamashita, Hiroyuki; Hirakura, Yutaka; Yuda, Masamichi; Teramura, Toshio; Terada, Katsuhide

2013-01-01

Although a number of studies have reported that cocrystals can form by heating a physical mixture of two components, details surrounding heat-induced cocrystal formation remain unclear. Here, we attempted to clarify the thermal behavior of a physical mixture and cocrystal formation in reference to a binary phase diagram. Physical mixtures prepared using an agate mortar were heated at rates of 2, 5, 10, and 30 °C/min using differential scanning calorimetry (DSC). Some mixtures were further analyzed using X-ray DSC and polarization microscopy. When a physical mixture consisting of two components which was capable of cocrystal formation was heated using DSC, an exothermic peak associated with cocrystal formation was detected immediately after an endothermic peak. In some combinations, several endothermic peaks were detected and associated with metastable eutectic melting, eutectic melting, and cocrystal melting. In contrast, when a physical mixture of two components which is incapable of cocrystal formation was heated using DSC, only a single endothermic peak associated with eutectic melting was detected. These experimental observations demonstrated how the thermal events were attributed to phase transitions occurring in a binary mixture and clarified the relationship between exothermic peaks and cocrystal formation.

Concentration addition and independent action model: Which is better in predicting the toxicity for metal mixtures on zebrafish larvae.

PubMed

Gao, Yongfei; Feng, Jianfeng; Kang, Lili; Xu, Xin; Zhu, Lin

2018-01-01

The joint toxicity of chemical mixtures has emerged as a popular topic, particularly on the additive and potential synergistic actions of environmental mixtures. We investigated the 24h toxicity of Cu-Zn, Cu-Cd, and Cu-Pb and 96h toxicity of Cd-Pb binary mixtures on the survival of zebrafish larvae. Joint toxicity was predicted and compared using the concentration addition (CA) and independent action (IA) models with different assumptions in the toxic action mode in toxicodynamic processes through single and binary metal mixture tests. Results showed that the CA and IA models presented varying predictive abilities for different metal combinations. For the Cu-Cd and Cd-Pb mixtures, the CA model simulated the observed survival rates better than the IA model. By contrast, the IA model simulated the observed survival rates better than the CA model for the Cu-Zn and Cu-Pb mixtures. These findings revealed that the toxic action mode may depend on the combinations and concentrations of tested metal mixtures. Statistical analysis of the antagonistic or synergistic interactions indicated that synergistic interactions were observed for the Cu-Cd and Cu-Pb mixtures, non-interactions were observed for the Cd-Pb mixtures, and slight antagonistic interactions for the Cu-Zn mixtures. These results illustrated that the CA and IA models are consistent in specifying the interaction patterns of binary metal mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct Prediction of Cricondentherm and Cricondenbar Coordinates of Natural Gas Mixtures using Cubic Equation of State

NASA Astrophysics Data System (ADS)

Taraf, R.; Behbahani, R.; Moshfeghian, Mahmood

2008-12-01

A numerical algorithm is presented for direct calculation of the cricondenbar and cricondentherm coordinates of natural gas mixtures of known composition based on the Michelsen method. In the course of determination of these coordinates, the equilibrium mole fractions at these points are also calculated. In this algorithm, the property of the distance from the free energy surfaces to a tangent plane in equilibrium condition is added to saturation calculation as an additional criterion. An equation of state (EoS) was needed to calculate all required properties. Therefore, the algorithm was tested with Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), and modified Nasrifar-Moshfeghian (MNM) equations of state. For different EoSs, the impact of the binary interaction coefficient ( k ij) was studied. The impact of initial guesses for temperature and pressure was also studied. The convergence speed and the accuracy of the results of this new algorithm were compared with experimental data and the results obtained from other methods and simulation softwares such as Hysys, Aspen Plus, and EzThermo.

Experimental and Modeling Study of the Burning of an Ethanol Droplet in Microgravity

NASA Technical Reports Server (NTRS)

Kazakov, Andrei; Conley, Jordan; Dryer, Frederick L.; Ferkul, Paul (Technical Monitor)

2000-01-01

The microgravity ethanol droplet combustion experiments were performed aboard the STS-94/MSL-1 Shuttle mission within the Fiber-Supported Droplet Combustion-2 (FSDC-2) program. The burning histories and flame standoffs for pure ethanol and ethanol/water droplets were obtained from the images recorded with two 8 mm videocameras. The obtained results show that average gasification rate is related to the initial droplet size in a manner similar to n-alkanes and methanol and consistent with the results of Hara and Kumagai and the data taken recently in the NASA-Lewis 2.2 s droptower. A transient, moving finite-element chemically reacting flow model applied previously to sphero-symmetric combustion of methanol, methanol/water, n-alkane, and n-alkane binary mixture droplets was adopted for the problem of ethanol droplet combustion. The model includes detailed description of gas-phase reaction chemistry and transport, a simplified description of liquid phase transport, and non-luminous radiative heat transfer. Gas-phase chemistry was described with the detailed reaction mechanism of Norton and Dryer, which consists of 142 reversible elementary reactions of 33 species. Another recently published reaction mechanism of high-temperature ethanol oxidation was also considered. The model predictions were found to compare favorably with the experimental data. The model analysis also indicates that water condensation in the case of ethanol has smaller effect on average droplet gasification rate as compared with previously studied methanol cases. This effect is explained by non-ideal (azeotropic) behavior of binary ethanol-water mixtures. Further analysis of computational results and ethanol droplet radiative extinction behavior will be discussed.

Secondhand Smoke-Prevalent Polycyclic Aromatic Hydrocarbon Binary Mixture-Induced Specific Mitogenic and Pro-inflammatory Cell Signaling Events in Lung Epithelial Cells.

PubMed

Osgood, Ross S; Upham, Brad L; Bushel, Pierre R; Velmurugan, Kalpana; Xiong, Ka-Na; Bauer, Alison K

2017-05-01

Low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs; < 206.3 g/mol) are prevalent and ubiquitous environmental contaminants, presenting a human health concern, and have not been as thoroughly studied as the high MW PAHs. LMW PAHs exert their pulmonary effects, in part, through P38-dependent and -independent mechanisms involving cell-cell communication and the production of pro-inflammatory mediators known to contribute to lung disease. Specifically, we determined the effects of two representative LMW PAHs, 1-methylanthracene (1-MeA) and fluoranthene (Flthn), individually and as a binary PAH mixture on the dysregulation of gap junctional intercellular communication (GJIC) and connexin 43 (Cx43), activation of mitogen activated protein kinases (MAPK), and induction of inflammatory mediators in a mouse non-tumorigenic alveolar type II cell line (C10). Both 1-MeA, Flthn, and the binary PAH mixture of 1-MeA and Flthn dysregulated GJIC in a dose and time-dependent manner, reduced Cx43 protein, and activated the following MAPKs: P38, ERK1/2, and JNK. Inhibition of P38 MAPK prevented PAH-induced dysregulation of GJIC, whereas inhibiting ERK and JNK did not prevent these PAHs from dysregulating GJIC indicating a P38-dependent mechanism. A toxicogenomic approach revealed significant P38-dependent and -independent pathways involved in inflammation, steroid synthesis, metabolism, and oxidative responses. Genes in these pathways were significantly altered by the binary PAH mixture when compared with 1-MeA and Flthn alone suggesting interactive effects. Exposure to the binary PAH mixture induced the production and release of cytokines and metalloproteinases from the C10 cells. Our findings with a binary mixture of PAHs suggest that combinations of LMW PAHs may elicit synergistic or additive inflammatory responses which warrant further investigation and confirmation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Secondhand Smoke-Prevalent Polycyclic Aromatic Hydrocarbon Binary Mixture-Induced Specific Mitogenic and Pro-inflammatory Cell Signaling Events in Lung Epithelial Cells

PubMed Central

Osgood, Ross S.; Upham, Brad L.; Bushel, Pierre R.; Velmurugan, Kalpana; Xiong, Ka-Na

2017-01-01

Abstract Low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs; < 206.3 g/mol) are prevalent and ubiquitous environmental contaminants, presenting a human health concern, and have not been as thoroughly studied as the high MW PAHs. LMW PAHs exert their pulmonary effects, in part, through P38-dependent and -independent mechanisms involving cell-cell communication and the production of pro-inflammatory mediators known to contribute to lung disease. Specifically, we determined the effects of two representative LMW PAHs, 1-methylanthracene (1-MeA) and fluoranthene (Flthn), individually and as a binary PAH mixture on the dysregulation of gap junctional intercellular communication (GJIC) and connexin 43 (Cx43), activation of mitogen activated protein kinases (MAPK), and induction of inflammatory mediators in a mouse non-tumorigenic alveolar type II cell line (C10). Both 1-MeA, Flthn, and the binary PAH mixture of 1-MeA and Flthn dysregulated GJIC in a dose and time-dependent manner, reduced Cx43 protein, and activated the following MAPKs: P38, ERK1/2, and JNK. Inhibition of P38 MAPK prevented PAH-induced dysregulation of GJIC, whereas inhibiting ERK and JNK did not prevent these PAHs from dysregulating GJIC indicating a P38-dependent mechanism. A toxicogenomic approach revealed significant P38-dependent and -independent pathways involved in inflammation, steroid synthesis, metabolism, and oxidative responses. Genes in these pathways were significantly altered by the binary PAH mixture when compared with 1-MeA and Flthn alone suggesting interactive effects. Exposure to the binary PAH mixture induced the production and release of cytokines and metalloproteinases from the C10 cells. Our findings with a binary mixture of PAHs suggest that combinations of LMW PAHs may elicit synergistic or additive inflammatory responses which warrant further investigation and confirmation. PMID:28329830

Viscosity, density, and surface tension of binary mixtures of water and N-methyldiethanolamine and water and diethanolamine and tertiary mixtures of these amines with water over the temperature range 20--100[degree]C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinker, E.B.; Oelschlager, D.W.; Colussi, A.T.

1994-04-01

Aqueous solutions of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) are widely used in the industrial treatment of acid gas streams containing H[sub 2]S and CO[sub 2]. The density and viscosity of aqueous solutions of N-methyldiethanolamine were measured over the temperature range 60--100 C. The density and viscosity of aqueous solutions of diethanolamine and diethanolamine + N-methyldiethanolamine were measured over the temperature range 20--100 C. The surface tension of aqueous solutions of the above mixtures was measured over the temperature range 20--80 C. The concentration ranges were 10--50 mass % N-methyldiethanolamine, 10--30 mass % diethanolamine, and 50 mass % total amine concentrationmore » with mass ratios of 0.0441--0.5883 (diethanolamine to N-methyldiethanolamine). The measured quantities were found to be in agreement with the literature where data were available.« less

Chromonic liquid crystalline nematic phase exhibited in binary mixture of two liquid crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Govindaiah, T. N., E-mail: tngovi.phy@gmail.com; Sreepad, H. R.; Sridhar, K. N.

2015-06-24

A binary mixture of abietic acid and orthophosphoric acid (H{sub 3}PO{sub 4}) exhibits co-existence of biphasic region of Nematic+Isotropic (N+I), lyotropic Nematic (ND) and Smectic-G (SmG) phases. The mixture exhibits N+I, N and SmG phases at different concentrations and at different temperatures. Mixtures with all concentrations of abietic acid exhibit I→N+I→N→SmG phases sequentially when the specimen is cooled from its isotropic melt. These phases have been characterized by using differential scanning calorimetric, X-ray diffraction, and optical texture studies.

Separation of C2 hydrocarbons from methane in a microporous metal-organic framework

NASA Astrophysics Data System (ADS)

Tang, Fu-Shun; Lin, Rui-Biao; Lin, Rong-Guang; Zhao, John Cong-Gui; Chen, Banglin

2018-02-01

The recovery of C2 hydrocarbons including acetylene, ethylene and ethane is challenging but important for natural gas upgrading. The separation of C2 hydrocarbons over methane was demonstrated here by using a microporous metal-organic framework [Zn3(OH)2(SDB)2] (H2SDB = 4,4'-sulfonyldibenzoic acid) consisting narrow one-dimensional pore channels. Gas sorption experiments revealed that this MOF material showed considerable uptake capacity for C2H2, C2H4 and C2H6 under ambient conditions, while its capacity for CH4 was very low. High selectivity from IAST calculations for C2H2/CH4, C2H4/CH4 and C2H6/CH4 binary mixtures demonstrated that this MOF material were promising for efficiently separating important separation of C2 hydrocarbons from methane in natural gas processing.

Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

PubMed Central

Cadena-Pereda, Raúl O.; Rivera-Muñoz, Eric M.; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J.; Anaya-Rivera, Ely K.

2012-01-01

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible. PMID:23112626

Automatic carbon dioxide-methane gas sensor based on the solubility of gases in water.

PubMed

Cadena-Pereda, Raúl O; Rivera-Muñoz, Eric M; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J; Anaya-Rivera, Ely K

2012-01-01

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0-100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

Determination of molecular diffusion coefficient in n-alkane binary mixtures: empirical correlations.

PubMed

De Mezquia, D Alonso; Bou-Ali, M Mounir; Larrañaga, M; Madariaga, J A; Santamaría, C

2012-03-08

In this work we have measured the molecular diffusion coefficient of the n-alkane binary series nC(i)-nC(6), nC(i)-nC(10), and nC(i)-nC(12) at 298 K and 1 atm and a mass fraction of 0.5 by using the so-called sliding symmetric tubes technique. The results show that the diffusion coefficient at this concentration is proportional to the inverse viscosity of the mixture. In addition, we have also measured the diffusion coefficient of the systems nC(12)-nC(6), nC(12)-nC(7), and nC(12)-nC(8) as a function of concentration. From the data obtained, it is shown that the diffusion coefficient of the n-alkane binary mixtures at any concentration can be calculated from the molecular weight of the components and the dynamic viscosity of the corresponding mixture at 50% mass fraction.

Composition measurements of binary mixture droplets by rainbow refractometry.

PubMed

Wilms, J; Weigand, B

2007-04-10

So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model.

Development and validation of new spectrophotometric ratio H-point standard addition method and application to gastrointestinal acting drugs mixtures.

PubMed

Yehia, Ali M

2013-05-15

New, simple, specific, accurate and precise spectrophotometric technique utilizing ratio spectra is developed for simultaneous determination of two different binary mixtures. The developed ratio H-point standard addition method (RHPSAM) was managed successfully to resolve the spectral overlap in itopride hydrochloride (ITO) and pantoprazole sodium (PAN) binary mixture, as well as, mosapride citrate (MOS) and PAN binary mixture. The theoretical background and advantages of the newly proposed method are presented. The calibration curves are linear over the concentration range of 5-60 μg/mL, 5-40 μg/mL and 4-24 μg/mL for ITO, MOS and PAN, respectively. Specificity of the method was investigated and relative standard deviations were less than 1.5. The accuracy, precision and repeatability were also investigated for the proposed method according to ICH guidelines. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and validation of new spectrophotometric ratio H-point standard addition method and application to gastrointestinal acting drugs mixtures

NASA Astrophysics Data System (ADS)

Yehia, Ali M.

2013-05-01

New, simple, specific, accurate and precise spectrophotometric technique utilizing ratio spectra is developed for simultaneous determination of two different binary mixtures. The developed ratio H-point standard addition method (RHPSAM) was managed successfully to resolve the spectral overlap in itopride hydrochloride (ITO) and pantoprazole sodium (PAN) binary mixture, as well as, mosapride citrate (MOS) and PAN binary mixture. The theoretical background and advantages of the newly proposed method are presented. The calibration curves are linear over the concentration range of 5-60 μg/mL, 5-40 μg/mL and 4-24 μg/mL for ITO, MOS and PAN, respectively. Specificity of the method was investigated and relative standard deviations were less than 1.5. The accuracy, precision and repeatability were also investigated for the proposed method according to ICH guidelines.

Joint acute and endocrine disruptive toxicities of malathion, cypermethrin and prochloraz to embryo-larval zebrafish, Danio rerio.

PubMed

Guo, Dongmei; Wang, Yanhua; Qian, Yongzhong; Chen, Chen; Jiao, Bining; Cai, Leiming; Wang, Qiang

2017-01-01

It remains a daunting challenge to determine ecotoxicological risks of exposure to mixtures of endocrine disrupting chemicals (EDCs) in environmental toxicology. In the present study, we investigated acute and endocrine disruptive toxicities of cypermethrin (CPM), malathion (MAL), prochloraz (PRO) and their binary mixtures of MAL + CPM and MAL + PRO to the early life stages of zebrafish. In the acute lethal toxicity test, three pesticides exhibited different levels of toxicity to zebrafish larvae, and the order of toxicity was as follows: CPM > PRO > MAL. The binary mixture of MAL + CPM displayed a synergistic effect on zebrafish larvae after exposure for 24, 48, 72 and 96 h. However, binary mixture of MAL + PRO showed an antagonistic effect. To evaluate the estrogenic effect, the expression of genes in the hypothalamic-pituitary-gonadal axis was assessed after zebrafish embryos were exposed to CPM, MAL, PRO and their binary mixtures from blastula stage (1 h post-fertilization, 1 hpf) to 14 dpf (14 d post-fertilization). Our data indicated that the transcription patterns of many key genes (vtg1, vtg2, era, erβ1, erβ2, cyp19a1a and cyp19a1b) were affected in hatched zebrafish after exposure to CPM, MAL and PRO. Moreover, following exposure to binary mixtures of 1000 μg/L MAL +4 μg/L CPM and 1000 μg/L MAL +900 μg/L PRO, the gene expressions were significantly changed compared with the individual pesticides. Our data provided a better understanding of bidirectional interactions of toxic response induced by these pesticides. Copyright © 2016 Elsevier Ltd. All rights reserved.

ThermoData Engine (TDE): software implementation of the dynamic data evaluation concept. 9. Extensible thermodynamic constraints for pure compounds and new model developments.

PubMed

Diky, Vladimir; Chirico, Robert D; Muzny, Chris D; Kazakov, Andrei F; Kroenlein, Kenneth; Magee, Joseph W; Abdulagatov, Ilmutdin; Frenkel, Michael

2013-12-23

ThermoData Engine (TDE) is the first full-scale software implementation of the dynamic data evaluation concept, as reported in this journal. The present article describes the background and implementation for new additions in latest release of TDE. Advances are in the areas of program architecture and quality improvement for automatic property evaluations, particularly for pure compounds. It is shown that selection of appropriate program architecture supports improvement of the quality of the on-demand property evaluations through application of a readily extensible collection of constraints. The basis and implementation for other enhancements to TDE are described briefly. Other enhancements include the following: (1) implementation of model-validity enforcement for specific equations that can provide unphysical results if unconstrained, (2) newly refined group-contribution parameters for estimation of enthalpies of formation for pure compounds containing carbon, hydrogen, and oxygen, (3) implementation of an enhanced group-contribution method (NIST-Modified UNIFAC) in TDE for improved estimation of phase-equilibrium properties for binary mixtures, (4) tools for mutual validation of ideal-gas properties derived through statistical calculations and those derived independently through combination of experimental thermodynamic results, (5) improvements in program reliability and function that stem directly from the recent redesign of the TRC-SOURCE Data Archival System for experimental property values, and (6) implementation of the Peng-Robinson equation of state for binary mixtures, which allows for critical evaluation of mixtures involving supercritical components. Planned future developments are summarized.

Binary gaseous mixture and single component adsorption of methane and argon on exfoliated graphite

NASA Astrophysics Data System (ADS)

Russell, Brice Adam

Exfoliated graphite was used as a substrate for adsorption of argon and methane. Adsorption experiments were conducted for both equal parts mixtures of argon and methane and for each gas species independently. The purpose of this was to compare mixture adsorption to single component adsorption and to investigate theoretical predictions concerning the kinetics of adsorption made by Burde and Calbi.6 In particular, time to reach pressure equilibrium of a single dose at a constant temperature for the equal parts mixture was compared to time of adsorption for each species by itself. It was shown that mixture adsorption is a much more complex and time consuming process than single component adsorption and requires a much longer amount of time to reach equilibrium. Information about the composition evolution of the mixture during the times when pressure was going toward equilibrium was obtained using a quadrupole mass spectrometer. Evidence for initial higher rate of adsorption for the weaker binding energy species (argon) was found as well as overall composition change which clearly indicated a higher coverage of methane on the graphite sample by the time equilibration was reached. Effective specific surface area of graphite for both argon and methane was also determined using the Point-B method.2

Synergism and Combinatorial Coding for Binary Odor Mixture Perception in Drosophila

PubMed Central

Chakraborty, Tuhin Subhra; Siddiqi, Obaid

2016-01-01

Most odors in the natural environment are mixtures of several compounds. Olfactory receptors housed in the olfactory sensory neurons detect these odors and transmit the information to the brain, leading to decision-making. But whether the olfactory system detects the ingredients of a mixture separately or treats mixtures as different entities is not well understood. Using Drosophila melanogaster as a model system, we have demonstrated that fruit flies perceive binary odor mixtures in a manner that is heavily dependent on both the proportion and the degree of dilution of the components, suggesting a combinatorial coding at the peripheral level. This coding strategy appears to be receptor specific and is independent of interneuronal interactions. PMID:27588303

Harnessing Active Fins to Segregate Nanoparticles from Binary Mixtures

NASA Astrophysics Data System (ADS)

Liu, Ya; Kuksenok, Olga; Bhattacharya, Amitabh; Ma, Yongting; He, Ximin; Aizenberg, Joanna; Balazs, Anna

2014-03-01

One of the challenges in creating high-performance polymeric nanocomposites for optoelectronic applications, such as bilayer solar cells, is establishing effective and facile routes for controlling the properties of interface and segregation of binary particles with hole conductor particles and electron conductor particles. We model nanocomposites that encompass binary particles and binary blends in a microchannel. An array of oscillating microfins is immersed in the fluid and tethered to the floor of the microchannel; the fluid containing mixture of nanoparticles is driven along the channel by an imposed pressure gradient. During the oscillations, the fins with the specific chemical wetting reach the upper fluid when they are upright and are entirely within the lower stream when they are tilted. We introduce specific interaction between the fins and particulates in the solution. Fins can selectively ``catch'' target nanoparticles within the upper fluid stream and then release them into the lower stream. We focus on different modes of fins motion to optimize selective segregation of particles within binary mixture. Our approach provides an effective means of tailoring the properties and ultimate performance of the composites.

An Exercise on Calibration: DRIFTS Study of Binary Mixtures of Calcite and Dolomite with Partially Overlapping Spectral Features

ERIC Educational Resources Information Center

De Lorenzi Pezzolo, Alessandra

2013-01-01

Unlike most spectroscopic calibrations that are based on the study of well-separated features ascribable to the different components, this laboratory experience is especially designed to exploit spectral features that are nearly overlapping. The investigated system consists of a binary mixture of two commonly occurring minerals, calcite and…

Communication: Virial coefficients and demixing in highly asymmetric binary additive hard-sphere mixtures.

PubMed

López de Haro, Mariano; Tejero, Carlos F; Santos, Andrés

2013-04-28

The problem of demixing in a binary fluid mixture of highly asymmetric additive hard spheres is revisited. A comparison is presented between the results derived previously using truncated virial expansions for three finite size ratios with those that one obtains with the same approach in the extreme case in which one of the components consists of point particles. Since this latter system is known not to exhibit fluid-fluid segregation, the similarity observed for the behavior of the critical constants arising in the truncated series in all instances, while not being conclusive, may cast serious doubts as to the actual existence of a demixing fluid-fluid transition in disparate-sized binary additive hard-sphere mixtures.

Microwave dielectric study of polar liquids at 298 K

NASA Astrophysics Data System (ADS)

Maharolkar, Aruna P.; Murugkar, A.; Khirade, P. W.

2018-05-01

Present paper deals with study of microwave dielectric properties like dielectric constant, viscosity, density and refractive index for the binary mixtures of Dimethylsulphoxide (DMSO) and Methanol over the entire concentration range were measured at 298K. The experimental data further used to determine the excess properties viz. excess static dielectric constant, excess molar volume, excess viscosity& derived properties viz. molar refraction&Bruggman factor. The values of excess properties further fitted with Redlich-Kister (R-K Fit) equation to calculate the binary coefficients and standard deviation. The resulting excess parameters are used to indicate the presence of intermolecular interactions and strength of intermolecular interactions between the molecules in the binary mixtures. Excess parameters indicate structure breaking factor in the mixture predominates in the system.

Thermo-acoustical molecular interaction study in binary mixtures of glycerol and ethylene glycol

NASA Astrophysics Data System (ADS)

Kaur, Kirandeep; Juglan, K. C.; Kumar, Harsh

2017-07-01

Ultrasonic velocity, density and viscosity are measured over the entire composition range for binary liquid mixtures of glycerol (CH2OH-CHOH-CH2OH) and ethylene glycol (HOCH2CH2OH) at different temperatures and constant frequency of 2MHz using ultrasonic interferometer, specific gravity bottle and viscometer respectively. Measured experimental values are used to obtained various acoustical parameters such as adiabatic compressibility, acoustic impedance, intermolecular free length, relaxation time, ultrasonic attenuation, effective molar weight, free volume, available volume, molar volume, Wada's constant, Rao's constant, Vander Waal's constant, internal pressure, Gibb's free energy and enthalpy. The variation in acoustical parameters are interpreted in terms of molecular interactions between the components of molecules of binary liquid mixtures.

Effect of stirring on the safety of flammable liquid mixtures.

PubMed

Liaw, Horng-Jang; Gerbaud, Vincent; Chen, Chan-Cheng; Shu, Chi-Min

2010-05-15

Flash point is the most important variable employed to characterize fire and explosion hazard of liquids. The models developed for predicting the flash point of partially miscible mixtures in the literature to date are all based on the assumption of liquid-liquid equilibrium. In real-world environments, however, the liquid-liquid equilibrium assumption does not always hold, such as the collection or accumulation of waste solvents without stirring, where complete stirring for a period of time is usually used to ensure the liquid phases being in equilibrium. This study investigated the effect of stirring on the flash-point behavior of binary partially miscible mixtures. Two series of partially miscible binary mixtures were employed to elucidate the effect of stirring. The first series was aqueous-organic mixtures, including water+1-butanol, water+2-butanol, water+isobutanol, water+1-pentanol, and water+octane; the second series was the mixtures of two flammable solvents, which included methanol+decane, methanol+2,2,4-trimethylpentane, and methanol+octane. Results reveal that for binary aqueous-organic solutions the flash-point values of unstirred mixtures were located between those of the completely stirred mixtures and those of the flammable component. Therefore, risk assessment could be done based on the flammable component flash-point value. However, for the assurance of safety, it is suggested to completely stir those mixtures before handling to reduce the risk. Copyright (c) 2010 Elsevier B.V. All rights reserved.

KEY COMPARISON Final report on international comparison CCQM-K71: Measurement of stack gas

NASA Astrophysics Data System (ADS)

Nieuwenkamp, G.; van der Veen, A. M. H.; Wessel, R. M.; Qiao, Han; Oh, Sang-Hyub; Kim, Byung-Moon; Kim, Kwang-Sub; Pérez Castorena, Alejandro; Ramírez Nambo, Carlos; Koelliker Delgado, Jorge; Serrano Caballero, Victor M.; Rangel Murillo, Francisco; Avila Salas, Manuel de Jesus; Dias, Florbela; Baptista, Gonçalo; Konopelko, L. A.; Kustikov, Y. A.; Pankratov, V. V.; Selyukov, D. N.; Balandovich, V. S.; Vishnyakov, I. M.; Pavlov, M. V.; Maltsev, M. A.; Botha, Angelique; Valkova, Miroslava; Stovcik, Viliam; Musil, Stanislav; Milton, M. J. T.; Uprichard, I. J.; Vargha, G. M.; Guenther, F.; Gameson, L.; da Cunha, V.

2010-01-01

Industrial stack gas emission measurements are important for process control, control of air pollution, and for implementing legislation regarding carbon dioxide emission rights. Measurements are typically performed using a range of process analysers for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and miscellaneous hydrocarbons. The calibration of these analysers is often performed using a series of binary mixtures of each component in nitrogen. For reasons of efficiency as well as a better match with true stack gas, the use of multi-component mixtures for this purpose would be preferred. The aim of this key comparison is to evaluate the measurement capabilities of national metrology institutes for carbon monoxide, carbon dioxide, nitrogen monoxide, sulphur dioxide and propane in nitrogen. Ten laboratories participated in the key comparison and one in the associated study. The key comparison reference value is based on the gravimetric preparation data. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Phase diagrams of Janus fluids with up-down constrained orientations

NASA Astrophysics Data System (ADS)

Fantoni, Riccardo; Giacometti, Achille; Maestre, Miguel Ángel G.; Santos, Andrés

2013-11-01

A class of binary mixtures of Janus fluids formed by colloidal spheres with the hydrophobic hemispheres constrained to point either up or down are studied by means of Gibbs ensemble Monte Carlo simulations and simple analytical approximations. These fluids can be experimentally realized by the application of an external static electrical field. The gas-liquid and demixing phase transitions in five specific models with different patch-patch affinities are analyzed. It is found that a gas-liquid transition is present in all the models, even if only one of the four possible patch-patch interactions is attractive. Moreover, provided the attraction between like particles is stronger than between unlike particles, the system demixes into two subsystems with different composition at sufficiently low temperatures and high densities.

METHOD FOR THE PREPARATION OF BINARY NITROGEN-FLUORINE COMPOUNDS

DOEpatents

Frazer, J.W.

1962-05-01

A process is given for preparing binary nitrogenfluorine compounds, in particular, tetrafluorohydrazine (N/sub 2/F/sub 4/) and difluorodiazine (N/sub 2/ F/sub 2/), The process comprises subjecting gaseous nitrogen trifluoride to the action of an alternating current electrical glow discharge in the presence of mercury vapors. By the action of the electrical discharge, the nitrogen trifluoride is converted into a gaseous product comprising a mixture of tetrafluorohydrazine, the isomers of difluorodiazine, and other impurities including nitrogen, nitrogen oxides, silicon tetrafiuoride, and unreacted nitrogen trifluoride. The gaseous products and impurities are passed into a trap maintained at about - 196 deg C to freeze out the desired products and impurities with the exception of nitregen gas which passes off from the trap and is discarded. Subsequently, the desired products and remaining impurities are warmed to the gaseous state and passed through a silica gel trap maintained at about - 55DEC, wherein the desired tetrafluorohydrazine and difluorodiazine products are retained while the remaining gaseous impurities pass therethrough. The desired products are volatilized from the silica gel trap by heating and then separated by gas chrounatography means into the respective tetrafluorohydrazine and difluorodiazine products. (A.e.C)

Toxic effect of metal cation binary mixtures to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta).

PubMed

Mendes, Luiz Fernando; Stevani, Cassius Vinicius; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Colepicolo, Pio

2014-01-01

The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism.

Adsorption and separation of binary and ternary mixtures of SO2, CO2 and N2 by ordered carbon nanotube arrays: grand-canonical Monte Carlo simulations.

PubMed

Rahimi, Mahshid; Singh, Jayant K; Müller-Plathe, Florian

2016-02-07

The adsorption and separation behavior of SO2-CO2, SO2-N2 and CO2-N2 binary mixtures in bundles of aligned double-walled carbon nanotubes is investigated using the grand-canonical Monte Carlo (GCMC) method and ideal adsorbed solution theory. Simulations were performed at 303 K with nanotubes of 3 nm inner diameter and various intertube distances. The results showed that the packing with an intertube distance d = 0 has the highest selectivity for SO2-N2 and CO2-N2 binary mixtures. For the SO2-CO2 case, the optimum intertube distance for having the maximum selectivity depends on the applied pressure, so that at p < 0.8 bar d = 0 shows the highest selectivity and at 0.8 bar < p < 2.5 bar, the highest selectivity belongs to d = 0.5 nm. Ideal adsorbed solution theory cannot predict the adsorption of the binary systems containing SO2, especially when d = 0. As the intertube distance is increased, the ideal adsorbed solution theory based predictions become closer to those of GCMC simulations. Only in the case of CO2-N2, ideal adsorbed solution theory is everywhere in good agreement with simulations. In a ternary mixture of all three gases, the behavior of SO2 and CO2 remains similar to that in a SO2-CO2 binary mixture because of the weak interaction between N2 molecules and CNTs.

Taste Mixture Interactions: Suppression, Additivity, and the Predominance of Sweetness

PubMed Central

Green, Barry G.; Lim, Juyun; Osterhoff, Floor; Blacher, Karen; Nachtigal, Danielle

2010-01-01

Most of what is known about taste interactions has come from studies of binary mixtures. The primary goal of this study was to determine whether asymmetries in suppression between stimuli in binary mixtures predict the perception of tastes in more complex mixtures (e.g., ternary, quaternary mixtures). Also of interest was the longstanding question of whether overall taste intensity derives from the sum of the tastes perceived within a mixture (perceptual additivity) or from the sum of the perceived intensities of the individual stimuli (stimulus additivity). Using the general Labeled Magnitude Scale together with a sip-and-spit procedure, we asked subjects to rate overall taste intensity and the sweetness, sourness, saltiness and bitterness of approximately equi- intense sucrose, NaCl, citric acid and QSO4 stimuli presented alone and in all possible binary, ternary and quaternary mixtures. The results showed a consistent pattern of mixture suppression in which sucrose sweetness tended to be both the least suppressed quality and the strongest suppressor of other tastes. The overall intensity of mixtures was found to be predicted best by perceptual additivity. A second experiment that was designed to rule out potentially confounding effects of the order of taste ratings and the temperature of taste solutions replicated the main findings of the first experiment. Overall, the results imply that mixture suppression favors perception of sweet carbohydrates in foods at the expense of other potentially harmful ingredients, such as high levels of sodium (saltiness) and potential poisons or spoilage (bitterness, sourness). PMID:20800076

Separation Potential for Multicomponent Mixtures: State-of-the Art of the Problem

NASA Astrophysics Data System (ADS)

Sulaberidze, G. A.; Borisevich, V. D.; Smirnov, A. Yu.

2017-03-01

Various approaches used in introducing a separation potential (value function) for multicomponent mixtures have been analyzed. It has been shown that all known potentials do not satisfy the Dirac-Peierls axioms for a binary mixture of uranium isotopes, which makes their practical application difficult. This is mainly due to the impossibility of constructing a "standard" cascade, whose role in the case of separation of binary mixtures is played by the ideal cascade. As a result, the only universal search method for optimal parameters of the separation cascade is their numerical optimization by the criterion of the minimum number of separation elements in it.

Surface tension of binary mixtures of water + N-methyldiethanolamine and ternary mixtures of this amine and water with monoethanolamine, diethanolamine, and 2-amino-2-methyl-1-propanol from 25 to 50 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez, E.; Rendo, R.; Sanjurjo, B.

1998-11-01

The surface tension of aqueous solutions of N-methyldiethanolamine and diethanolamine + N-methyldiethanolamine, monoethanolamine + N-methyldiethanolamine and 2-amino-2-methyl-1-propanol + N-methyldiethanolamine was measured at temperatures from 25 C to 50 C. For binary mixtures the concentration range was 0--50 mass % N-methyldiethanolamine, and for the tertiary mixtures the concentration range for each amine was 0--50 mass %. The experimental values were correlated with temperature and mole fraction. The maximum deviation in both cases was always less than 0.5%.

Transport properties of nonelectrolyte mixtures. IX. Viscosity coefficients for acetonitrile and for three mixtures of toluene+acetonitrile from 25 to 100°c at pressures up to 500 MPa

NASA Astrophysics Data System (ADS)

Dymond, J. H.; Awan, M. A.; Glen, N. F.; Isdale, J. D.

1991-05-01

A two-coil self-centering falling-body viscometer has been used to measure viscosity coefficients for acetonitrile and three binary mixtures of toluene+ acetonitrile at 25, 50, 75, and 100°C and pressures up to 500 MPa. The results for acetonitrile can be interpreted by an approach based on hard-sphere theory, with a roughness factor of 1.46. The binary-mixture data are well represented by the Grunberg and Nissan equation with a mixing parameter which is pressure and temperature dependent but composition independent.

Viscosities of nonelectrolyte liquid mixtures. II. Binary mixtures of n-hexane with alkanoates and bromoalkanoates

NASA Astrophysics Data System (ADS)

Oswal, S. L.; Dave, J. P.

1992-11-01

Viscosity measurements are reported for mixtures of ethyl ethanoate, ethyl propionate, ethyl butyrate, ethyl-2-bromopropionate, ethyl-3-bromopropionate, ethyl-2-bromobutyrate, and ethyl-4-bromobutyrate with n-hexane at 303.15 K. The viscosity data have been correlated with equations of Grunberg and Nissan, of McAllister, and of Auslaender. Furthermore, excess Gibbs energies of activation ΔG * E of viscous flow have been calculated with Eyring's theory of absolute reaction rates and values of ΔG * E for the present binary mixtures have been explained in terms of the dipole-dipole interaction in alkanoates and the intramolecular Br...O interaction in bromoalkanoates.

Viscosity minima in binary mixtures of ionic liquids + molecular solvents.

PubMed

Tariq, M; Shimizu, K; Esperança, J M S S; Canongia Lopes, J N; Rebelo, L P N

2015-05-28

The viscosity (η) of four binary mixtures (ionic liquids plus molecular solvents, ILs+MSs) was measured in the 283.15 < T/K < 363.15 temperature range. Different IL/MS combinations were selected in such a way that the corresponding η(T) functions exhibit crossover temperatures at which both pure components present identical viscosity values. Consequently, most of the obtained mixture isotherms, η(x), exhibit clear viscosity minima in the studied T-x range. The results are interpreted using auxiliary molecular dynamics (MD) simulation data in order to correlate the observed η(T,x) trends with the interactions in each mixture, including the balance between electrostatic forces and hydrogen bonding.

Refractive Index Mixing Rules and Excess Infrared Spectra of Binary Mixtures.

PubMed

Baranović, Goran

2017-05-01

Three refractive index mixing rules, Arago-Biot, Lorentz-Lorenz, and Newton, are generalized to complex refractive index and used to define infrared (IR) spectra of the corresponding ideal liquid mixtures. Using the measured optical constants n and k for acetonitrile-water mixtures (Bertie and Lan, 1997) the excess absorbances, A E  =  A obs  -  A ideal , are calculated. Relying upon the well-established properties of the acetonitrile-water mixtures, the interpretation of the excess absorbances is established that is essentially based on the understanding of a liquid as a set of oscillators. The set depends on the composition of the mixture and comprises oscillators as present in the pure components and oscillators perturbed by hydrogen bonding between unlike molecules. The main features of an excess spectrum can be established assuming chemical equilibria among various oscillators. The most informative parts of the spectrum of a yet unstudied binary system can well be observed and even qualitatively explained from the excess absorbance provided: first, a detailed vibrational study of the components has been done; and, second, it is well understood what actually is subtracted from A obs . As examples, the binary mixtures of ethynylbenzene and tetrachloroethylene and 2-ethynylpyridine and tetrachloroethylene are considered.

Combining nitrogen fertilizer with poultry litter in a binary mixture of tall fescue and bermudagrass

USDA-ARS?s Scientific Manuscript database

A common problem when poultry litter is applied to pastures in the southeastern USA is the buildup of soil P because of the difference in N-P-K ratio of the litter and plant requirements. This 2-yr study tested the theory that if the N requirement of a tall fescue-bermudagrass binary mixture is only...

A globally accurate theory for a class of binary mixture models

NASA Astrophysics Data System (ADS)

Dickman, Adriana G.; Stell, G.

The self-consistent Ornstein-Zernike approximation results for the 3D Ising model are used to obtain phase diagrams for binary mixtures described by decorated models, yielding the plait point, binodals, and closed-loop coexistence curves for the models proposed by Widom, Clark, Neece, and Wheeler. The results are in good agreement with series expansions and experiments.

On hydrodynamic phase field models for binary fluid mixtures

NASA Astrophysics Data System (ADS)

Yang, Xiaogang; Gong, Yuezheng; Li, Jun; Zhao, Jia; Wang, Qi

2018-05-01

Two classes of thermodynamically consistent hydrodynamic phase field models have been developed for binary fluid mixtures of incompressible viscous fluids of possibly different densities and viscosities. One is quasi-incompressible, while the other is incompressible. For the same binary fluid mixture of two incompressible viscous fluid components, which one is more appropriate? To answer this question, we conduct a comparative study in this paper. First, we visit their derivation, conservation and energy dissipation properties and show that the quasi-incompressible model conserves both mass and linear momentum, while the incompressible one does not. We then show that the quasi-incompressible model is sensitive to the density deviation of the fluid components, while the incompressible model is not in a linear stability analysis. Second, we conduct a numerical investigation on coarsening or coalescent dynamics of protuberances using the two models. We find that they can predict quite different transient dynamics depending on the initial conditions and the density difference although they predict essentially the same quasi-steady results in some cases. This study thus cast a doubt on the applicability of the incompressible model to describe dynamics of binary mixtures of two incompressible viscous fluids especially when the two fluid components have a large density deviation.

Thermodynamics of concentrated electrolyte mixtures and the prediction of mineral solubilities to high temperatures for mixtures in the system Na-K-Mg-Cl-SO 4-OH-H 2O

NASA Astrophysics Data System (ADS)

Pabalan, Roberto T.; Pitzer, Kenneth S.

1987-09-01

Mineral solubilities in binary and ternary electrolyte mixtures in the system Na-K-Mg-Cl-SO 4-OH-H 2O are calculated to high temperatures using available thermodynamic data for solids and for aqueous electrolyte solutions. Activity and osmotic coefficients are derived from the ion-interaction model of Pitzer (1973, 1979) and co-workers, the parameters of which are evaluated from experimentally determined solution properties or from solubility data in binary and ternary mixtures. Excellent to good agreement with experimental solubilities for binary and ternary mixtures indicate that the model can be successfully used to predict mineral-solution equilibria to high temperatures. Although there are currently no theoretical forms for the temperature dependencies of the various model parameters, the solubility data in ternary mixtures can be adequately represented by constant values of the mixing term θ ij and values of ψ ijk which are either constant or have a simple temperature dependence. Since no additional parameters are needed to describe the thermodynamic properties of more complex electrolyte mixtures, the calculations can be extended to equilibrium studies relevant to natural systems. Examples of predicted solubilities are given for the quaternary system NaCl-KCl-MgCl 2-H 2O.

Essential Oil of Aristolochia trilobata: Synthesis, Routes of Exposure, Acute Toxicity, Binary Mixtures and Behavioral Effects on Leaf-Cutting Ants.

PubMed

de Oliveira, Bruna Maria S; Melo, Carlisson R; Alves, Péricles B; Santos, Abraão A; Santos, Ane Caroline C; Santana, Alisson da S; Araújo, Ana Paula A; Nascimento, Pedro E S; Blank, Arie F; Bacci, Leandro

2017-02-25

Plants of the genus Aristolochia have been frequently reported as important medicinal plants. Despite their high bioactive potential, to date, there are no reports of their effects on leaf-cutting ants. Therefore, the present study aimed to evaluate the insecticidal activity of the essential oil of Aristolochia trilobata and its major components on Atta sexdens and Acromyrmex balzani , two species of leaf-cutting ants. The bioassays were performed regarding routes of exposure, acute toxicity, binary mixtures of the major components and behavioral effects. Twenty-five components were identified in the essential oil of A. trilobata using a gas chromatographic system equipped with a mass spectrometer and a flame ionization detector. The components found in higher proportions were sulcatyl acetate, limonene, p -cymene and linalool. The essential oil of A. trilobata and its individual major components were efficient against A. balzani and A. sexdens workers when applied by fumigation. These components showed fast and efficient insecticidal activity on ants. The components acted synergistically and additively on A. balzani and A. sexdens , respectively, and caused a strong repellency/irritability in the ants. Thus, our results demonstrate the great potential of the essential oil of A. trilobata and its major components for the development of new insecticides.

Modeling CO2 mass transfer in amine mixtures: PZ-AMP and PZ-MDEA.

PubMed

Puxty, Graeme; Rowland, Robert

2011-03-15

The most common method of carbon dioxide (CO(2)) capture is the absorption of CO(2) into a falling thin film of an aqueous amine solution. Modeling of mass transfer during CO(2) absorption is an important way to gain insight and understanding about the underlying processes that are occurring. In this work a new software tool has been used to model CO(2) absorption into aqueous piperazine (PZ) and binary mixtures of PZ with 2-amino-2-methyl-1-propanol (AMP) or methyldiethanolamine (MDEA). The tool solves partial differential and simultaneous equations describing diffusion and chemical reaction automatically derived from reactions written using chemical notation. It has been demonstrated that by using reactions that are chemically plausible the mass transfer in binary mixtures can be fully described by combining the chemical reactions and their associated parameters determined for single amines. The observed enhanced mass transfer in binary mixtures can be explained through chemical interactions occurring in the mixture without need to resort to using additional reactions or unusual transport phenomena such as the "shuttle mechanism".

Microlayered flow structure around an acoustically levitated droplet under a phase-change process.

PubMed

Hasegawa, Koji; Abe, Yutaka; Goda, Atsushi

2016-01-01

The acoustic levitation method (ALM) has found extensive applications in the fields of materials science, analytical chemistry, and biomedicine. This paper describes an experimental investigation of a levitated droplet in a 19.4-kHz single-axis acoustic levitator. We used water, ethanol, water/ethanol mixture, and hexane as test samples to investigate the effect of saturated vapor pressure on the flow field and evaporation process using a high-speed camera. In the case of ethanol, water/ethanol mixtures with initial ethanol fractions of 50 and 70 wt%, and hexane droplets, microlayered toroidal vortexes are generated in the vicinity of the droplet interface. Experimental results indicate the presence of two stages in the evaporation process of ethanol and binary mixture droplets for ethanol content >10%. The internal and external flow fields of the acoustically levitated droplet of pure and binary mixtures are clearly observed. The binary mixture of the levitated droplet shows the interaction between the configurations of the internal and external flow fields of the droplet and the concentration of the volatile fluid. Our findings can contribute to the further development of existing theoretical prediction.

The Phase Behavior of γ-Oryzanol and β-Sitosterol in Edible Oil.

PubMed

Sawalha, Hassan; Venema, Paul; Bot, Arjen; Flöter, Eckhard; Adel, Ruud den; van der Linden, Erik

The phase behavior of binary mixtures of γ-oryzanol and β-sitosterol and ternary mixtures of γ-oryzanol and β-sitosterol in sunflower oil was studied. Binary mixtures of γ-oryzanol and β-sitosterol show double-eutectic behavior. Complex phase behavior with two intermediate mixed solid phases was derived from differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) data, in which a compound that consists of γ-oryzanol and β-sitosterol molecules at a specific ratio can be formed. SAXS shows that the organization of γ-oryzanol and β-sitosterol in the mixed phases is different from the structure of tubules in ternary systems. Ternary mixtures including sunflower oil do not show a sudden structural transition from the compound to a tubule, but a gradual transition occurs as γ-oryzanol and β-sitosterol are diluted in edible oil. The same behavior is observed when melting binary mixtures of γ-oryzanol and β-sitosterol at higher temperatures. This indicates the feasibility of having an organogelling agent in dynamic exchange between solid and liquid phase, which is an essential feature of triglyceride networks.

Molecular Dynamics Simulation Study of the Capacitive Performance of a Binary Mixture of Ionic Liquids near an Onion-like Carbon Electrode.

PubMed

Li, Song; Feng, Guang; Fulvio, Pasquale F; Hillesheim, Patrick C; Liao, Chen; Dai, Sheng; Cummings, Peter T

2012-09-06

An equimolar mixture of 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C3mpy][Tf2N]), 1-methyl-1-butylpiperidinium bis(trifluoromethylsulfonyl)imide ([C4mpip][Tf2N]) was investigated by classic molecular dynamics (MD) simulation. Differential scanning calorimetry (DSC) measurements verified that the binary mixture exhibited lower glass transition temperature than either of the pure room-temperature ionic liquids (RTILs). Moreover, the binary mixture gave rise to higher conductivity than the neat RTILs at lower temperature range. In order to study its capacitive performance in supercapacitors, simulations were performed of the mixture, and the neat RTILs used as electrolytes near an onion-like carbon (OLC) electrode at varying temperatures. The differential capacitance exhibited independence of the electrical potential applied for three electrolytes, which is in agreement with previous work on OLC electrodes in a different RTILs. Positive temperature dependence of the differential capacitance was observed, and it was dominated by the electrical double layer (EDL) thickness, which is for the first time substantiated in MD simulation.

Thermal phase diagram of acetamide-benzoic acid and benzoic acid-phthalimide binary systems for solar thermal applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Rohitash, E-mail: dootrohit1976@gmail.com; Department of Physics & Center for Solar Energy, Indian Institute of Technology Jodhpur, Rajasthan, India 342011, +91-291-2449045; Kumar, Ravindra

2016-05-06

Thermal properties of Acetamide (AM) – Benzoic acid (BA) and Benzoic acid (BA) – Phthalimide (PM) binary eutectic systems are theoretically calculated using thermodynamic principles. We found that the binary systems of AM-BA at 67.6 : 32.4 molar ratio, BA-PM at 89.7 : 10.3 molar ratio form eutectic mixtures with melting temperatures ~ 54.5 °C and 114.3 °C respectively. Calculated latent heat of fusion for these eutectic mixtures are 191 kJ/kg and 146.5 kJ/kg respectively. These melting temperatures and heat of fusions of these eutectic mixtures make them suitable for thermal energy storage applications in solar water heating and solarmore » cooking systems.« less

Study of molecular interactions in binary mixtures of 2-chloro-4'methoxy benzoin with various solvents through ultrasonic speed measurements

NASA Astrophysics Data System (ADS)

Thanuja, B.; Kanakam, C.; Nithya, G.

2013-12-01

Density ( ρ) and ultrasonic velocity ( U), for binary mixtures of 2-chloro-4'-methoxy benzoin with ethanol, chloroform, acetonitrile, benzene and 1,4-dioxane of different compositions have been measured at 298 K and explanation of solute solvent interactions and effect of polarity of the solvent on type of interactions are presented in this paper. From the above data, adiabatic compressibility ( β), intermolecular free length ( L f ) and relative association ( R A ) have been calculated. Other useful parameters such as excess density, excess velocity, excess intermolecular freelength and excess adiabatic compressibility have also been calculated. These parameters have been used to study the nature and extent of intermolecular interactions between component molecules in present binary mixtures.

Thermodynamic Parameters of Cholesteric/Smectic A Transition in Cholesteric Myristate and Its Binary Mixture CM/PCPB

NASA Astrophysics Data System (ADS)

Yurtseven, H.; Dogan, E. Kilit

2018-06-01

Thermodynamic properties of the cholesteryl myristate (CM) and its binary mixture CM/PCPB ( p-pentylphenyl-2-chloro-4( p-pentylbenzoyl)-benzoate) are studied at the concentrations of x PCPB = 0.052 and 0.219 as a function of temperature near the cholosteric/smectic A transition. By analyzing the observed molar volume from the literature, the temperature dependences of the thermal expansion, isothermal compressibility and the difference in the specific heat are calculated and, the Pippard relations are established for those compounds close to the cholesteric/smectic A transition. Predictions of the thermodynamic quantities and the Pippard relations can be examined by the experimental measurements of the CM and its binary mixture of CM/PCPB close to the cholesteric/smectic A transition.

Uniform phases in fluids of hard isosceles triangles: One-component fluid and binary mixtures

NASA Astrophysics Data System (ADS)

Martínez-Ratón, Yuri; Díaz-De Armas, Ariel; Velasco, Enrique

2018-05-01

We formulate the scaled particle theory for a general mixture of hard isosceles triangles and calculate different phase diagrams for the one-component fluid and for certain binary mixtures. The fluid of hard triangles exhibits a complex phase behavior: (i) the presence of a triatic phase with sixfold symmetry, (ii) the isotropic-uniaxial nematic transition is of first order for certain ranges of aspect ratios, and (iii) the one-component system exhibits nematic-nematic transitions ending in critical points. We found the triatic phase to be stable not only for equilateral triangles but also for triangles of similar aspect ratios. We focus the study of binary mixtures on the case of symmetric mixtures: equal particle areas with aspect ratios (κi) symmetric with respect to the equilateral one, κ1κ2=3 . For these mixtures we found, aside from first-order isotropic-nematic and nematic-nematic transitions (the latter ending in a critical point): (i) a region of triatic phase stability even for mixtures made of particles that do not form this phase at the one-component limit, and (ii) the presence of a Landau point at which two triatic-nematic first-order transitions and a nematic-nematic demixing transition coalesce. This phase behavior is analogous to that of a symmetric three-dimensional mixture of rods and plates.

Leakiness of Pinned Neighboring Surface Nanobubbles Induced by Strong Gas-Surface Interaction.

PubMed

Maheshwari, Shantanu; van der Hoef, Martin; Rodrı Guez Rodrı Guez, Javier; Lohse, Detlef

2018-03-27

The stability of two neighboring surface nanobubbles on a chemically heterogeneous surface is studied by molecular dynamics (MD) simulations of binary mixtures consisting of Lennard-Jones (LJ) particles. A diffusion equation-based stability analysis suggests that two nanobubbles sitting next to each other remain stable, provided the contact line is pinned, and that their radii of curvature are equal. However, many experimental observations seem to suggest some long-term kind of ripening or shrinking of the surface nanobubbles. In our MD simulations we find that the growth/dissolution of the nanobubbles can occur due to the transfer of gas particles from one nanobubble to another along the solid substrate. That is, if the interaction between the gas and the solid is strong enough, the solid-liquid interface can allow for the existence of a "tunnel" which connects the liquid-gas interfaces of the two nanobubbles to destabilize the system. The crucial role of the gas-solid interaction energy is a nanoscopic element that hitherto has not been considered in any macroscopic theory of surface nanobubbles and may help to explain experimental observations of the long-term ripening.

Production of Ar and Xe metastables in rare gas mixtures in a dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Mikheyev, Pavel A.; Han, Jiande; Clark, Amanda; Sanderson, Carl; Heaven, Michael C.

2017-12-01

Optically pumped all-rare-gas lasers (OPRGL) utilize metastable atoms of the heavier rare gases as lasing species. The required number density of metastables for efficient laser operation is 1012-1013 cm-3 in He buffer gas at pressures in the 400-1000 Torr range. Such metastable densities are easily produced in a nanosecond pulsed discharge, even at pressures larger than atmospheric, but problems appear when one is trying to achieve continuous production. The reason for low production efficiency in many types of continuous discharge at atmospheric pressure is the low value of the E/N parameter (<5-6 Td). In the present work, we have examined the possibility of using a dielectric barrier discharge (DBD) to provide near continuous, high densities of Ar and Xe metastables. Experiments were performed using a 20 kHz DBD in binary Ar and Xe mixtures with He, and in ternary Ar:Xe:He mixtures at pressures up to 1 atmosphere. Concentrations were measured by means of tunable diode laser absorption spectroscopy. Time-averaged [Ar(1s5)] and [Xe(1s5)] number densities on the order of 1012 cm-3 were readily achieved. The temporal behavior of [Xe(1s5)] throughout the DBD cycle was observed. The results demonstrate the feasibility of using DBDs for OPRGL development. Spectral scans over the absorption lines were also used to examine the pressure broadening coefficients for the 912.3 nm Ar line in He and the Xe 904.5 nm line in Ne and He.

Kirkwood–Buff integrals for ideal solutions

PubMed Central

Ploetz, Elizabeth A.; Bentenitis, Nikolaos; Smith, Paul E.

2010-01-01

The Kirkwood–Buff (KB) theory of solutions is a rigorous theory of solution mixtures which relates the molecular distributions between the solution components to the thermodynamic properties of the mixture. Ideal solutions represent a useful reference for understanding the properties of real solutions. Here, we derive expressions for the KB integrals, the central components of KB theory, in ideal solutions of any number of components corresponding to the three main concentration scales. The results are illustrated by use of molecular dynamics simulations for two binary solutions mixtures, benzene with toluene, and methanethiol with dimethylsulfide, which closely approach ideal behavior, and a binary mixture of benzene and methanol which is nonideal. Simulations of a quaternary mixture containing benzene, toluene, methanethiol, and dimethylsulfide suggest this system displays ideal behavior and that ideal behavior is not limited to mixtures containing a small number of components. PMID:20441282

Silo discharge of binary granular mixtures.

PubMed

Madrid, M; Asencio, K; Maza, D

2017-08-01

We present numerical and experimental results on the mass flow rate during the discharge of three-dimensional silos filled with a bidisperse mixture of grains of different sizes. We analyzed the influence of the ratio between coarse and fine particles on the profile of volume fraction and velocity across the orifice. By using numerical simulations, we have shown that the velocity profile has the same shape as that in the monodisperse case and is insensitive to the composition of the mixture. On the contrary, the volume fraction profile is strongly affected by the composition of the mixture. Assuming that an effective particle size can be introduced to characterize the mixture, we have shown that previous expression for the mass flow rate of monodisperse particles can be used for binary mixtures. A comparison with Beverloo's correlation is also presented.

Coal liquefaction process using pretreatment with a binary solvent mixture

DOEpatents

Miller, R.N.

1986-10-14

An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300 C before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil. 1 fig.

Coal liquefaction process using pretreatment with a binary solvent mixture

DOEpatents

Miller, Robert N.

1986-01-01

An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300.degree. C. before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil.

Composition measurements of binary mixture droplets by rainbow refractometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilms, J.; Weigand, B

2007-04-10

So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup wasmore » used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model.« less

Effective interactions in a quantum Bose-Bose mixture

NASA Astrophysics Data System (ADS)

Utesov, O. I.; Baglay, M. I.; Andreev, S. V.

2018-05-01

We generalize the Beliaev diagrammatic theory of an interacting spinless Bose-Einstein condensate to the case of a binary mixture. We derive a set of coupled Dyson equations and find analytically the Green's functions of the system. The elementary excitation spectrum consists of two branches, one of which takes the characteristic parabolic form ω ∝p2 in the limit of a spin-independent interaction. We observe renormalization of the magnon mass and the spin-wave velocity due to the Andreev-Bashkin entrainment effect. For a three-dimensional weakly interacting gas the spectrum can be obtained by applying the Bogoliubov transformation to a second-quantized Hamiltonian in which the microscopic two-body potentials in each channel are replaced by the corresponding off-shell scattering amplitudes. The superfluid drag density can be calculated by considering a mixture of phonons and magnons interacting via the effective potentials. We show that this problem is identical to the second-order perturbative treatment of a Bose polaron. In two dimensions the drag contributes to the magnon dispersion already in the first approximation. Our consideration provides a basis for systematic study of emergent phases in quantum degenerate Bose-Bose mixtures.

Individual and binary mixture effects of bisphenol A and lignin-derived bisphenol in Daphnia magna under chronic exposure.

PubMed

Li, Dan; Chen, Hongxing; Bi, Ran; Xie, Haibo; Zhou, Yu; Luo, Yongju; Xie, Lingtian

2018-01-01

In recent years, many new chemicals have been synthesized from biomass with an aim for sustainable development by replacing the existing toxic chemicals with those having similar properties and applications. However, the effects of these new chemicals on aquatic organisms remain relatively unknown. In this study, the effects of bisphenol A (BPA) and lignin-derived bisphenol (LD-BP, a BPA analogue) on Daphnia magna were evaluated. The animals were exposed to BPA, LD-BP, and their binary mixture at concentrations (2-2000 μg L -1 ) for 21 days. The expression of various biochemical markers and the effects on growth, molting, and reproduction parameters were examined. The results showed that the weight of daphnids significantly increased after exposure to BPA, LD-BP, and the binary mixture relative to that of the control animals. The activity of superoxide dismutase was significantly inhibited by LD-BP and the binary mixture. At the highest exposure concentration of the binary mixture, the activities of acetylcholinesterase and α-glucosidase, fecundity, and the number of neonates per brood were significantly altered. Our results showed that the effects of BPA and LD-BP on D. magna were generally comparable, except for the effect on the weight at their environmentally relevant concentrations (e.g., <20 μg L -1 ). The effects on the reproduction of D. magna could be mainly due to the shift in energy redistribution under BPA and LD-BP exposures. Our results implied that exposures to both BPA and LD-BP could potentially cause deleterious effects at the population level in D. magna. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heterogeneous structure and solvation dynamics of DME/water binary mixtures: A combined spectroscopic and simulation investigation

NASA Astrophysics Data System (ADS)

Das Mahanta, Debasish; Rana, Debkumar; Patra, Animesh; Mukherjee, Biswaroop; Mitra, Rajib Kumar

2018-05-01

Water is often found in (micro)-heterogeneous environments and therefore it is necessary to understand their H-bonded network structure in such altered environments. We explore the structure and dynamics of water in its binary mixture with relatively less polar small biocompatible amphiphilic molecule 1,2-Dimethoxyethane (DME) by a combined spectroscopic and molecular dynamics (MD) simulation study. Picosecond (ps) resolved fluorescence spectroscopy using coumarin 500 as the fluorophore establishes a non-monotonic behaviour of the mixture. Simulation studies also explore the various possible H-bond formations between water and DME. The relative abundance of such different water species manifests the heterogeneity in the mixture.

Influence of the Kinetics of Heat and Mass Transfer in a Binary-Rectification Column on the Realizability Range of its Regimes

NASA Astrophysics Data System (ADS)

Zaeva, M. A.; Tsirlin, A. M.; Sukin, I. A.

2018-05-01

The range of realizable rates of flows in a binary-rectification column in which heat is supplied into the boiler and is removed from the dephlegmator was investigated. It is shown that this range is determined by two characteristic parameters related to the kinetics of heat and mass transfer in the column and the composition of the mixture subjected to separation. The limiting capabilities of a cascade of two binary-rectification columns for the separation of a ternary mixture in it were considered. The conditions for an optimum sequence of separation of a mixture in this cascade and for a consistent arrangement of its heat and mass exchange surfaces and the relation between the ultimate production rate of the cascade and the total heat losses in it were determined.

Influence of the Kinetics of Heat and Mass Transfer in a Binary-Rectification Column on the Realizability Range of its Regimes

NASA Astrophysics Data System (ADS)

Zaeva, M. A.; Tsirlin, A. M.; Sukin, I. A.

2018-03-01

The range of realizable rates of flows in a binary-rectification column in which heat is supplied into the boiler and is removed from the dephlegmator was investigated. It is shown that this range is determined by two characteristic parameters related to the kinetics of heat and mass transfer in the column and the composition of the mixture subjected to separation. The limiting capabilities of a cascade of two binary-rectification columns for the separation of a ternary mixture in it were considered. The conditions for an optimum sequence of separation of a mixture in this cascade and for a consistent arrangement of its heat and mass exchange surfaces and the relation between the ultimate production rate of the cascade and the total heat losses in it were determined.

Mixing and demixing of binary mixtures of polar chiral active particles.

PubMed

Ai, Bao-Quan; Shao, Zhi-Gang; Zhong, Wei-Rong

2018-05-17

We study a binary mixture of polar chiral (counterclockwise or clockwise) active particles in a two-dimensional box with periodic boundary conditions. Besides the excluded volume interactions between particles, the particles are also subjected to the polar velocity alignment. From the extensive Brownian dynamics simulations, it is found that the particle configuration (mixing or demixing) is determined by the competition between the chirality difference and the polar velocity alignment. When the chirality difference competes with the polar velocity alignment, the clockwise particles aggregate in one cluster and the counterclockwise particles aggregate in the other cluster; thus, the particles are demixed and can be separated. However, when the chirality difference or the polar velocity alignment is dominant, the particles are mixed. Our findings could be used for the experimental pursuit of the separation of binary mixtures of chiral active particles.

Ultrasonic studies of intermolecular interactions in binary mixtures of 4-methoxy benzoin with various solvents: Excess molar functions of ultrasonic parameters at different concentrations and in different solvents.

PubMed

Thanuja, B; Nithya, G; Kanagam, Charles C

2012-11-01

Density (ρ), ultrasonic velocity (U), for the binary mixtures of 4-methoxy benzoin (4MB) with ethanol, chloroform, acetonitrile, benzene, and di-oxane were measured at 298K. The solute-solvent interactions and the effect of the polarity of the solvent on the type of intermolecular interactions are discussed here. From the above data, adiabatic compressibility (β), intermolecular free length (L(f)), acoustic impedance (Z), apparent molar volume (Ø), relative association (RA) have been calculated. Other useful parameters such as excess density, excess velocity and excess adiabatic compressibility have also been calculated. These parameters were used to study the nature and extent of intermolecular interactions between component molecules in the binary mixtures. Copyright © 2012 Elsevier B.V. All rights reserved.

Multisubstrate biodegradation kinetics of naphthalene, phenanthrene, and pyrene mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guha, S.; Peters, C.A.; Jaffe, P.R.

Biodegradation kinetics of naphthalene, phenanthrene and pyrene were studied in sole-substrate systems, and in binary and ternary mixtures to examine substrate interactions. The experiments were conducted in aerobic batch aqueous systems inoculated with a mixed culture that had been isolated from soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Monod kinetic parameters and yield coefficients for the individual parameters and yield coefficients for the individual compounds were estimated from substrate depletion and CO{sub 2} evolution rate data in sole-substrate experiments. In all three binary mixture experiments, biodegradation kinetics were comparable to the sole-substrate kinetics. In the ternary mixture, biodegradation of naphthalenemore » was inhibited and the biodegradation rates of phenanthrene and pyrene were enhanced. A multisubstrate form of the Monod kinetic model was found to adequately predict substrate interactions in the binary and ternary mixtures using only the parameters derived from sole-substrate experiments. Numerical simulations of biomass growth kinetics explain the observed range of behaviors in PAH mixtures. In general, the biodegradation rates of the more degradable and abundant compounds are reduced due to competitive inhibition, but enhanced biodegradation of the more recalcitrant PAHs occurs due to simultaneous biomass growth on multiple substrates. In PAH-contaminated environments, substrate interactions may be very large due to additive effects from the large number of compounds present.« less

Properties of L-ascorbic acid in water and binary aqueous mixtures of D-glucose and D-fructose at different temperatures

NASA Astrophysics Data System (ADS)

Sharma, Ravi; Thakur, R. C.; Sani, Balwinder; Kumar, Harsh

2017-12-01

Using density and sound velocity partial molar volumes, partial molar adiabatic compressibilities, partial molar expansibilities and structure of L-ascorbic acid have been determined in water and aqueous mixtures of D-glucose and D-fructose at different concentrations and temperatures. Masson's equation was used to analyze the measured data. The obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. It is found that the L-ascorbic acid acts as structure breaker in water as well in binary studied mixtures.

Determination of solvents permeating through chemical protective clothing with a microsensor array.

PubMed

Park, J; Zellers, E T

2000-08-01

The performance of a novel prototype instrument in determining solvents and solvent mixtures permeating through samples of chemical protective clothing (CPC) materials was evaluated. The instrument contains a mini-preconcentrator and an array of three polymer-coated surface-acoustic-wave (SAW) microsensors whose collective response patterns are used to discriminate among multiple permeants. Permeation tests were performed with a 2.54 cm diameter test cell in an open-loop configuration on samples of common glove materials challenged with four individual solvents, three binary mixtures, and two ternary mixtures. Breakthrough times, defined as the times required for the permeation rate to reach a value of 1 microg cm(-2) min(-1), determined by the instrument were within 3 min of those determined in parallel by manual sampling and gas chromatographic analysis. Permeating solvents were recognized (identified) from their response patterns in 59 out of 64 measurements (92%) and their vapor concentrations were quantified to an accuracy of +/- 31% (typically +/- 10%). These results demonstrate the potential for such instrumentation to provide semi-automated field or bench-top screening of CPC permeation resistance.

Rheological characterizations of concentrated binary gum mixtures with xanthan gum and galactomannans.

PubMed

Jo, Wonjun; Bak, June Ha; Yoo, Byoungseung

2018-03-20

The steady and dynamic shear rheological properties of binary gum mixtures with xanthan gum (XG) and galactomannans (guar gum (GG) and locust bean gum (LBG)) were examined in a concentrated solution (1% w/w) as a function of gum mixing ratio (100/0, 75/25, 50/50, and 0/100). All samples, except for individual GG and LBG, showed high shear-thinning behavior with yield stress. The values of flow (K, η a,50 , and σ oc ) and dynamic rheological parameters (G' and G″) of XG-GG and XG-LBG mixtures were significantly higher compared to XG alone, indicating that the flow and viscoelastic properties of binary gum mixtures were greatly affected by the addition of GG and LBG. The maximum elasticity synergistic interaction for XG-galactomannans mixtures was observed at a mixing ratio of 50/50, showing a greatly positive deviation between measured and calculated values of G'. These results suggest that the synergistic effect of GG and LBG addition on rheological properties of XG appears to be due to intermolecular interaction occurred between XG and galactomannans, as confirmed by dynamic rheological properties. Copyright © 2018 Elsevier B.V. All rights reserved.

Microlayered flow structure around an acoustically levitated droplet under a phase-change process

PubMed Central

Hasegawa, Koji; Abe, Yutaka; Goda, Atsushi

2016-01-01

The acoustic levitation method (ALM) has found extensive applications in the fields of materials science, analytical chemistry, and biomedicine. This paper describes an experimental investigation of a levitated droplet in a 19.4-kHz single-axis acoustic levitator. We used water, ethanol, water/ethanol mixture, and hexane as test samples to investigate the effect of saturated vapor pressure on the flow field and evaporation process using a high-speed camera. In the case of ethanol, water/ethanol mixtures with initial ethanol fractions of 50 and 70 wt%, and hexane droplets, microlayered toroidal vortexes are generated in the vicinity of the droplet interface. Experimental results indicate the presence of two stages in the evaporation process of ethanol and binary mixture droplets for ethanol content >10%. The internal and external flow fields of the acoustically levitated droplet of pure and binary mixtures are clearly observed. The binary mixture of the levitated droplet shows the interaction between the configurations of the internal and external flow fields of the droplet and the concentration of the volatile fluid. Our findings can contribute to the further development of existing theoretical prediction. PMID:28725723

Thermochemical parameters of minerals from oxygen-buffered hydrothermal equilibrium data: Method, application to annite and almandine

USGS Publications Warehouse

Zen, E.-A.

1973-01-01

Reversed univariant hydrothermal phase-equilibrium reactions, in which a redox reaction occurs and is controlled by oxygen buffers, can be used to extract thermochemical data on minerals. The dominant gaseous species present, even for relatively oxidizing buffers such as the QFM buffer, are H2O and H2; the main problem is to calculate the chemical potentials of these components in a binary mixture. The mixing of these two species in the gas phase was assumed by Eugster and Wones (1962) to be ideal; this assumption allows calculation of the chemical potentials of the two components in a binary gas mixture, using data in the literature. A simple-mixture model of nonideal mixing, such as that proposed by Shaw (1967), can also be combined with the equations of state for oxygen buffers to permit derivation of the chemical potentials of the two components. The two mixing models yield closely comparable results for the more oxidizing buffers such as the QFM buffer. For reducing buffers such as IQF, the nonideal-mixing correction can be significant and the Shaw model is better. The procedure of calculation of mineralogical thermochemical data, in reactions where hydrogen and H2O simultaneously appear, is applied to the experimental data on annite, given by Wones et al. (1971), and on almandine, given by Hsu (1968). For annite the results are: Standard entropy of formation from the elements, Sf0 (298, 1)=-283.35??2.2 gb/gf, S0 (298, 1) =+92.5 gb/gf. Gf0 (298, 1)=-1148.2??6 kcal, and Hf0 (298, 1)=-1232.7??7 kcal. For almandine, the calculation takes into account the mutual solution of FeAl2O4 (Hc) in magnetite and of Fe3O4 (Mt) in hercynite and the temperature dependence of this solid solution, as given by Turnock and Eugster (1962); the calculations assume a regular-solution model for this binary spinel system. The standard entropy of formation of almandine, Sf,A0 (298, 1) is -272.33??3 gb/gf. The third law entropy, S0 (298, 1) is +68.3??3 gb/gf, a value much less than the oxide-sum estimate but the deviation is nearly the same as that of grossularite, referring to a comparable set of oxide standard states. The Gibbs free energy Gf,A0 (298, 1) is -1192.36??4 kcal, and the enthalpy Hf,A0 (298, 1) is -1273.56??5 kcal. ?? 1973 Springer-Verlag.

Calculating the surface tension of binary solutions of simple fluids of comparable size

NASA Astrophysics Data System (ADS)

Zaitseva, E. S.; Tovbin, Yu. K.

2017-11-01

A molecular theory based on the lattice gas model (LGM) is used to calculate the surface tension of one- and two-component planar vapor-liquid interfaces of simple fluids. Interaction between nearest neighbors is considered in the calculations. LGM is applied as a tool of interpolation: the parameters of the model are corrected using experimental surface tension data. It is found that the average accuracy of describing the surface tension of pure substances (Ar, N2, O2, CH4) and their mixtures (Ar-O2, Ar-N2, Ar-CH4, N2-CH4) does not exceed 2%.

Applications of the Soave-Redlich-Kwong Equations of State Using Mathematic

NASA Astrophysics Data System (ADS)

Sun, Lanyi; Zhai, Cheng; Zhang, Hui

The application of the Peng-Robinson equations of state (PR EOS) using Matlab and Mathematic has already been demonstrated. In this paper, using Mathematic to solve Soave-Redlich-Kwong (SRK) EOS, as well as the estimation of pure component properties, plotting of vapor-liquid equilibrium (VLE) diagram and calculation of chemical equilibrium, is presented. First the SRK EOS is used to predict several pure-component properties, such as liquid and gas molar volumes for isobutane. The vapor-liquid isobaric diagram is then plotted for a binary mixture composed of n-pentane and n-hexane under the pressures of 2*10^5 and 8*10^5 Pa respectively.

Stability of surface nanobubbles

NASA Astrophysics Data System (ADS)

Maheshwari, Shantanu; van der Hoef, Martin; Zhang, Xuehua; Lohse, Detlef

2015-11-01

We have studied the stability and dissolution of surface nanobubbles on the chemical heterogenous surface by performing Molecular Dynamics (MD) simulations of binary mixture consists of Lennard-Jones (LJ) particles. Recently our group has derived the exact expression for equilibrium contact angle of surface nanobubbles as a function of oversaturation of the gas concentration in bulk liquid and the lateral length of bubble. It has been showed that the contact line pinning and the oversaturation of gas concentration in bulk liquid is crucial in the stability of surface nanobubbles. Our simulations showed that how pinning of the three-phase contact line on the chemical heterogenous surface lead to the stability of the nanobubble. We have calculated the equilibrium contact angle by varying the gas concentration in bulk liquid and the lateral length of the bubble. Our results showed that the equilibrium contact angle follows the expression derived analytically by our group. We have also studied the bubble dissolution dynamics and showed the ''stick-jump'' mechanism which was also observed experimentally in case of dissolution of nanodrops.

MUTUAL DIFFUSION OF PAIRS OF RARE GASES AT DIFFERENT TEMPERATURES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, B.N.; Srivastava, K.P.

1959-04-01

The eoefficient of mutual diffusion of the binary gas mixtures Ne--Ar, Ar--Krs and Ne--Kr has been determined at 0, 15, 30s and 45 C. Diffusion is allowed to take place between two diffusion bulbs through a precision capillary tube and samples of gas are withdrawn from one bulb at different times and analyzed by a differential conductivity analyzer. From the experimentally determined values of the diffusion coefficient at different temperatures the unlike interaction parameters for the above gas pairs have been calculated by two different methods on the Lennard-Jones I2:6 model. These values of the force parameters are found tomore » be in good agreement with those obtained from the usual combination rules and also from the thermal diffusion data following the method of Srivastava and Madan. These values are found to reproduce the experimental data on mutual diffusion quite satisfactorily. With Kelvin's method, these data have also been utilized to calculate the self-diffusion coefficient of neon, argons and krypton. (auth)« less

Pervaporative stripping of acetone, butanol and ethanol to improve ABE fermentation.

PubMed

Jitesh, K; Pangarkar, V G; Niranjan, K

2000-01-01

Acetone-butanol-ethanol fermentation by anaerobic bacterium C. acetobutylicum is a potential source for feedstock chemicals. The problem of product induced inhibition makes this fermentation economically infeasible. Pervaporation is studied as an effective separation technique to remove the toxic inhibitory products. Various membranes like Styrene Butadiene Rubber (SBR), Ethylene Propylene Diene Rubber (EPDM), plain Poly Dimethyl Siloxane (PDMS) and silicalite filled PDMS were studied for the removal of acetone, butanol and ethanol, from binary aqueous mixtures and from a quaternary mixture. It was found that the overall performance of PDMS filled with 15% w/w of silicalite was the best for removal of butanol in binary mixture study. SBR performance was best for the quaternary mixture studied.

Transport properties of nonelectrolyte liquid mixtures. VIII. Viscosity coefficients for toluene and for three mixtures of toluene + hexane from 25 to 100°C at pressures up to 500 MPa

NASA Astrophysics Data System (ADS)

Dymond, J. H.; Awan, M. A.; Glen, N. F.; Isdale, J. D.

1991-03-01

Viscosity coefficients measured using a two-coil self-centering falling-body viscometer are reported for toluene and three binary mixtures of toluene + n-hexane at 25, 50, 75, and 100°C at pressures up to 500 MPa. The data for a given composition at different temperatures and pressures are correlated very satisfactorily by a plot of reduced viscosity η * versus log V', where V'= V· V 0(TR)/V0(T) and V 0 represents a characteristic volume. The binary mixture data are well represented by the Grunberg and Nissan equation with a mixing parameter which is pressure dependent but composition and temperature independent.

Dielectric properties of binary mixtures of methyl iso butyl ketone and amino silicone oil

NASA Astrophysics Data System (ADS)

Shah, K. N.; Rana, V. A.; Trivedi, C. M.; Vankar, H. P.

2017-05-01

Dielectric permittivity ɛ*(ω) = ɛ' - jɛ″ of the binary mixtures of the methyl iso butyl ketone and amino silicone oil in the frequency range 100 Hz to 2 MHz were measured using precision LCR meter at 305.15 K. Relative complex permittivity spectra in the frequency range 100 Hz to 2 MHz, of the mixture solutions of varying concentrations is reported. Determined values of the permittivity at optical frequency of all the samples are also reported. The dielectric parameters are used to gain information about the effect of concentration variation of components of the mixtures on the dielectric properties. It also provides the information about electrode polarization phenomena taking place under the low frequency A.C. electric field.

Preferential solvation of lysozyme in dimethyl sulfoxide/water binary mixture probed by terahertz spectroscopy.

PubMed

Das, Dipak Kumar; Patra, Animesh; Mitra, Rajib Kumar

2016-09-01

We report the changes in the hydration dynamics around a model protein hen egg white lysozyme (HEWL) in water-dimethyl sulfoxide (DMSO) binary mixture using THz time domain spectroscopy (TTDS) technique. DMSO molecules get preferentially solvated at the protein surface, as indicated by circular dichroism (CD) and Fourier transform infrared (FTIR) study in the mid-infrared region, resulting in a conformational change in the protein, which consequently modifies the associated hydration dynamics. As a control we also study the collective hydration dynamics of water-DMSO binary mixture and it is found that it follows a non-ideal behavior owing to the formation of DMSO-water clusters. It is observed that the cooperative dynamics of water at the protein surface does follow the DMSO-mediated conformational modulation of the protein. Copyright © 2016 Elsevier B.V. All rights reserved.

Raman bandshape analysis on CH and CSC stretching modes of dimethyl sulfoxide in liquid binary mixture: comparative study with quantum-chemical calculations.

PubMed

Upadhyay, Ganesh; Gomti Devi, Th

2014-12-10

The interacting nature of dimethyl sulfoxide (DMSO) in binary mixtures has been carried out on CH and CSC stretching modes of vibration using chloroform (CLF), chloroform-d (CLFd), acetonitrile (ACN) and acetonitrile-d3 (ACNd) solvents. Peak frequencies of both the stretching modes show blue shift with the increase in solvent concentration. Variation of Raman bandwidth with the solvent concentration was discussed using different mechanisms. Ab initio calculation for geometry optimization and vibrational wavenumber calculation have been performed on monomer and dimer structures of DMSO to explain the experimentally observed Raman spectra. Theoretically calculated values are found in good agreement with the experimental results. Vibrational and reorientational relaxation times have been studied corresponding to solvent concentrations to elucidate the interacting mechanisms of binary mixtures. Copyright © 2014 Elsevier B.V. All rights reserved.

Binary Phase Behavior of Saturated-Unsaturated Mixed-Acid Triacylglycerols-A Review.

PubMed

Zhang, Lu; Ueno, Satoru; Sato, Kiyotaka

2018-06-01

Most natural lipids contain a complex mixture of individual triacylglycerols (TAGs). An in-depth knowledge of the mixing behavior of TAGs is necessary for the rational design and engineering of food materials. The binary phase diagram of TAGs is a simplified model that can be explored to help foster an understanding of the phase behavior of complex fats and oils. This article reviews recent research on the binary phase behavior of saturated-unsaturated mixed-acid TAGs, with special emphasis on the stearicunsaturated and palmitic-unsaturated diacid TAGs. The occurrence of polymorphic forms and mutual solubility of TAG mixtures are strongly related to the glycerol conformation of the saturated-oleic diacid TAGs; it appears to be most influenced by the chain-length mismatch in saturated-elaidic diacid TAGs. In addition, the polymorphism of pure enantiomers and racemic mixture of chiral TAGs was also reviewed, while the effect of chirality on mixing behavior was discussed.

The toxicity of binary mixture of Cu (II) ion and phenols on Tetrahymena thermophila.

PubMed

Luo, Hui; Li, Xi; Fang, Tingting; Liu, Peng; Zhang, Chaocan; Xie, Hao; Sun, Enjie

2015-03-01

The toxicity of binary mixture of Cu(2+) and phenols (phenol; o-nitrophenol; m-nitrophenol; p-nitrophenol) was evaluated using Tetrahymena thermophila as the model organism, by microcalorimetry, optical density, field emission scanning electron microscope (FESEM) and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The growth curves and metabolic properties of Tetrahymena exposed to Cu(2+) and phenols were monitored by microcalorimetry. Binary mixture toxicity changed with the concentration of Cu(2+)/phenols and the order of toxicity was Cu(2+)/phenol

Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

PubMed

Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

2015-11-05

Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

Study of complex permittivity spectra of binary mixtures of 2-chloroaniline and methanol in frequency range 10 KHz to 2 MHz at different temperatures

NASA Astrophysics Data System (ADS)

Shah, N. S.; Vankar, H. P.; Rana, V. A.

2017-05-01

The complex relative dielectric function ɛ*(ω)=ɛ'-jɛ″ of the binary mixture of 2-chloroaniline(2-CA) and methanol (MeOH) were measured using precision LCR meter in the frequency range of 10 KHz to 2 MHz The measurements were carried out at eight different temperatures and five different concentrations of 2-CA and MeOH. The loss tangent peaks were observed in the studied frequency range for all the binary mixtures. From the loss tangent peaks electrode polarization relaxation time were evaluated. In the plot of real part of complex permittivity against frequency, at different temperatures for 2-CA (54.54%) + MeOH (45.45%) and 2-CA (27.27%) + MeOH (72.72%)and 100% MeOH systems permittivity inversion effect was observed.

Study of intermolecular interactions in binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil in various solvents and at different concentrations by the measurement of acoustic properties.

PubMed

Nithya, G; Thanuja, B; Kanagam, Charles C

2013-01-01

Density (ρ), ultrasonic velocity (u), adiabatic compressibility (β), apparent molar volume (Ø), acoustic impedance (Z), intermolecular free length (L(f)), relative association (RA) of binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil (abbreviated as 2CBe) in ethanol, acetonitrile, chloroform, dioxane and benzene were measured at different concentrations at 298 K. Several useful parameters such as excess density, excess ultrasonic velocity, excess adiabatic compressibility, excess apparent molar volume, excess acoustic impedance and excess intermolecular free length have been calculated. These parameters are used to explain the nature of intermolecular interactions taking place in the binary mixture. The above study is useful in understanding the solute--solvent interactions occurring in different concentrations at room temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

Simulation of gas diffusion and sorption in nanoceramic semiconductors

NASA Astrophysics Data System (ADS)

Skouras, E. D.; Burganos, V. N.; Payatakes, A. C.

1999-05-01

Gas diffusion and sorption in nanoceramic semiconductors are studied using atomistic simulation techniques and numerical results are presented for a variety of sorbate-sorbent systems. SnO2, BaTiO3, CuO, and MgO substrates are built on the computer using lattice constants and atomic parameters that have been either measured or computed by ab initio methods. The Universal force field is employed here for the description of both intramolecular and nonbonded interactions for various gas sorbates, including CH4, CO, CO2, and O2, pure and in binary mixtures. Mean residence times are determined by molecular dynamics computations, whereas the Henry constant and the isosteric heat of adsorption are estimated by a Monte Carlo technique. The effects of surface hydroxylation on the diffusion and sorption characteristics are quantified and discussed in view of their significance in practical gas sensing applications. The importance of fast diffusion on the response time of the sensitive layer and of the sorption efficiency on the overall sensitivity as well as the potential synergy of the two phenomena are discussed.

Study of the influence of surfactants on the activity coefficients and mass transfer coefficients of methanol in aqueous mixtures by reversed-flow gas chromatography.

PubMed

Kotsalos, Efthimios; Brezovska, Boryana; Sevastos, Dimitrios; Vagena, Artemis; Koliadima, Athanasia; Kapolos, John; Karaiskakis, George

2017-11-17

This work focuses on the influences of surfactants on the activity coefficients, γ, of methanol in binary mixtures with water, as well as on the mass transfer coefficients, k c , for the evaporation of methanol, which is a ubiquitous component in the troposphere, from mixtures of methanol with water at various surfactant's and methanol's concentrations. The technique used is the Reversed-Flow Gas Chromatography (R.F.G.C.), a version of Inverse Gas Chromatography, which allows determining both parameters by performing only one experiment for the k c parameter and two experiments for the γ parameter. The k c and γ values decrease in the presence of the three surfactants used (CTAB, SDS, TRITON X-100) at all methanol's and surfactant's concentrations. The decrease in the methanol's molar fraction, at constant number of surfactant films leads to a decrease in the k c and γ values, while the decrease in the surfactant's concentration, at constant methanol's molar fraction leads to an increase in both the k c and γ parameters. Mass transfer coefficients for the evaporation of methanol at the surfactant films, are also calculated which are approximately between 4 and 5 orders of magnitude larger than the corresponding mass transfer coefficients at the liquid films. Finally, thicknesses of the boundary layer of methanol in the mixtures of methanol with water were determined. The quantities found are compared with those given in the literature or calculated theoretically using various empirical equations. The precision of the R.F.G.C. method for measuring γ and k c parameters is approximately high (94.3-98.0%), showing that R.F.G.C. can be used with success not only for the thermodynamic study of solutions, but also for the interphase transport. Copyright © 2017 Elsevier B.V. All rights reserved.

High temperature regenerative H.sub.2 S sorbents

NASA Technical Reports Server (NTRS)

Flytani-Stephanopoulos, Maria (Inventor); Gavalas, George R. (Inventor); Tamhankar, Satish S. (Inventor)

1988-01-01

Efficient, regenerable sorbents for removal of H.sub.2 S from high temperature gas streams comprise porous, high surface area particles. A first class of sorbents comprise a thin film of binary oxides that form a eutectic at the temperature of the gas stream coated onto a porous, high surface area refractory support. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as a film of V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O coated on an alumina support. A second class of sorbents consist of particles of unsupported mixed oxides in the form of highly dispersed solid solutions of solid compounds characterized by small crystallite size, high porosity and relatively high surface area. The mixed oxide sorbents contain one Group IB, IIB or VIIB metal oxide such as copper, zinc or manganese and one or more oxides of Groups IIIA, VIB or VII such as aluminum, iron or molybdenum. The presence of iron or aluminum maintains the Group IB, IIB or VIIB metal in its oxidized state. Presence of molybdenum results in eutectic formation at sulfidation temperature and improves the efficiency of the sorbent.

Wetting phenomenon in the liquid-vapor phase coexistence of a partially miscible Lennard-Jones binary mixture

NASA Astrophysics Data System (ADS)

Ramírez-Santiago, Guillermo; Díaz-Herrera, Enrique; Moreno Razo, José A.

2004-03-01

We have carried out extensive equilibrium MD simulations to study wetting phenomena in the liquid-vapor phase coexistence of a partially miscible binary LJ mixture. We find that in the temperature range 0.60 ≤ T^* < 0.80, the system separates forming a liquid A-liquid B interface in coexistence with the vapor phase. At higher temperatures, 0.80 ≤ T^* < 1.25 the liquid phases are wet by the vapor phase. By studying the behavior of the surface tension as a function of temperature we estimate the wetting transition temperature (WTT) to be T^*_w≃ 0.80. The adsorption of molecules at the liquid-liquid interface shows a discontinuity at about T^*≃ 0.79 suggesting that the wetting transition is a first order phase transition. These results are in agreement with some experiments carried out in fluid binary mixtures. In addition, we estimated the consolute temperature to be T^* _cons≃ 1.25. The calculated phase diagram of the mixture suggest the existence of a tricritical point.

Novel spectrophotometric methods for simultaneous determination of timolol and dorzolamide in their binary mixture.

PubMed

Lotfy, Hayam Mahmoud; Hegazy, Maha A; Rezk, Mamdouh R; Omran, Yasmin Rostom

2014-05-21

Two smart and novel spectrophotometric methods namely; absorbance subtraction (AS) and amplitude modulation (AM) were developed and validated for the determination of a binary mixture of timolol maleate (TIM) and dorzolamide hydrochloride (DOR) in presence of benzalkonium chloride without prior separation, using unified regression equation. Additionally, simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of the binary mixture namely; simultaneous ratio subtraction (SRS), ratio difference (RD), ratio subtraction (RS) coupled with extended ratio subtraction (EXRS), constant multiplication method (CM) and mean centering of ratio spectra (MCR). The proposed spectrophotometric procedures do not require any separation steps. Accuracy, precision and linearity ranges of the proposed methods were determined and the specificity was assessed by analyzing synthetic mixtures of both drugs. They were applied to their pharmaceutical formulation and the results obtained were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one regarding both accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.

Separating Iso-Propanol-Toluene mixture by azeotropic distillation

NASA Astrophysics Data System (ADS)

Iqbal, Asma; Ahmad, Syed Akhlaq

2018-05-01

The separation of Iso-Propanol-Toluene azeotropic mixture using Acetone as an entrainer has been simulated on Aspen Plus software package using rigorous methods. Calculations of the vapor-liquid equilibrium for the binary system are done using UNIQUAC-RK model which gives a good agreement with the experimental data reported in literature. The effects of the Reflux ratio (RR), distillate-to-feed molar ratio (D/F), feed stage, solvent feed stage, Total no. of stages and solvent feed temperature on the product purities and recoveries are studied to obtain their optimum values that give the maximum purity and recovery of products. The configuration consists of 20 theoretical stages with an equimolar feed of binary mixture. The desired separation of binary mixture has been achieved at the feed stage and an entrainer feeding stage of 15 and 12 respectively with the reflux ratios of 2.5 and 4.0, and D/F ratio of 0.75 and 0.54 respectively in the two columns. The simulation results thus obtained are useful to setup the optimal column configuration of the azeotropic distillation process.

Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christen, Verena; Crettaz, Pierre; Oberli-Schrämmli, Aurelia

2012-03-01

Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC{sub 10}, EC{sub 25} and EC{sub 50} in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approachmore » (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC{sub 10} mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC{sub 25} mixture of DBP + BPA. A ternary mixture revealed synergism at the EC{sub 50}, and weak antagonistic activity at the EC{sub 25} level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.« less

The virial coefficients of hard hypersphere binary mixtures

NASA Astrophysics Data System (ADS)

Enciso, E.; Almarza, N. G.; Gonzalez, M. A.; Bermejo, F. J.

The third, fourth and fifth virial coefficients of hard hypersphere binary mixtures with dimensionality d = 4, 5 have been calculated for size ratios R ≥0.1, R ı σ22 / σ11 , where σ ii is the diameter of component i . The composition independent partial virial coefficients have been evaluated by Monte Carlo integration of the corresponding Mayer modified star diagrams. The results are compared with the predictions of Santos, S., Yuste, S. B., and Lopez de Haro, M., 1999, Molec. Phys ., 96 , 1 of the equation of state of a multicomponent mixture of hard hyperspheres, and the good agreement gives strong support to the validity of that recipe.

Ion-water wires in imidazolium-based ionic liquid/water solutions induce unique trends in density.

PubMed

Ghoshdastidar, Debostuti; Senapati, Sanjib

2016-03-28

Ionic liquid/water binary mixtures are rapidly gaining popularity as solvents for dissolution of cellulose, nucleobases, and other poorly water-soluble biomolecules. Hence, several studies have focused on measuring the thermophysical properties of these versatile mixtures. Among these, 1-ethyl-3-methylimidazolium ([emim]) cation-based ILs containing different anions exhibit unique density behaviours upon addition of water. While [emim][acetate]/water binary mixtures display an unusual rise in density with the addition of low-to-moderate amounts of water, those containing the [trifluoroacetate] ([Tfa]) anion display a sluggish decrease in density. The density of [emim][tetrafluoroborate] ([emim][BF4])/water mixtures, on the other hand, declines rapidly in close accordance with the experimental reports. Here, we unravel the structural basis underlying this unique density behavior of [emim]-based IL/water mixtures using all-atom molecular dynamics (MD) simulations. The results revealed that the distinct nature of anion-water hydrogen bonded networks in the three systems was a key in modulating the observed unique density behaviour. Vast expanses of uninterrupted anion-water-anion H-bonded stretches, denoted here as anion-water wires, induced significant structuring in [emim][Ac]/water mixtures that resulted in the density rise. Conversely, the presence of intermittent large water clusters disintegrated the anion-water wires in [emim][Tfa]/water and [emim][BF4]/water mixtures to cause a monotonic density decrease. The differential nanostructuring affected the dynamics of the solutions proportionately, with the H-bond making and breaking dynamics found to be greatly retarded in [emim][Ac]/water mixtures, while it exhibited a faster relaxation in the other two binary solutions.

Improving the de-agglomeration and dissolution of a poorly water soluble drug by decreasing the agglomerate strength of the cohesive powder.

PubMed

Allahham, Ayman; Stewart, Peter J; Das, Shyamal C

2013-11-30

Influence of ternary, poorly water-soluble components on the agglomerate strength of cohesive indomethacin mixtures during dissolution was studied to explore the relationship between agglomerate strength and extent of de-agglomeration and dissolution of indomethacin (Ind). Dissolution profiles of Ind from 20% Ind-lactose binary mixtures, and ternary mixtures containing additional dibasic calcium phosphate (1% or 10%; DCP), calcium sulphate (10%) and talc (10%) were determined. Agglomerate strength distributions were estimated by Monte Carlo simulation of particle size, work of cohesion and packing fraction distributions. The agglomerate strength of Ind decreased from 1.19 MPa for the binary Ind mixture to 0.84 MPa for 1DCP:20Ind mixture and to 0.42 MPa for 1DCP:2Ind mixture. Both extent of de-agglomeration, demonstrated by the concentration of the dispersed indomethacin distribution, and extent of dispersion, demonstrated by the particle size of the dispersed indomethacin, were in descending order of 1DCP:2Ind>1DCP:20Ind>binary Ind. The addition of calcium sulphate dihydrate and talc also reduced the agglomerate strength and improved de-agglomeration and dispersion of indomethacin. While not definitively causal, the improved de-agglomeration and dispersion of a poorly water soluble drug by poorly water soluble components was related to the agglomerate strength of the cohesive matrix during dissolution. Copyright © 2013 Elsevier B.V. All rights reserved.

Hierarchically self-assembled hexagonal honeycomb and kagome superlattices of binary 1D colloids.

PubMed

Lim, Sung-Hwan; Lee, Taehoon; Oh, Younghoon; Narayanan, Theyencheri; Sung, Bong June; Choi, Sung-Min

2017-08-25

Synthesis of binary nanoparticle superlattices has attracted attention for a broad spectrum of potential applications. However, this has remained challenging for one-dimensional nanoparticle systems. In this study, we investigate the packing behavior of one-dimensional nanoparticles of different diameters into a hexagonally packed cylindrical micellar system and demonstrate that binary one-dimensional nanoparticle superlattices of two different symmetries can be obtained by tuning particle diameter and mixing ratios. The hexagonal arrays of one-dimensional nanoparticles are embedded in the honeycomb lattices (for AB 2 type) or kagome lattices (for AB 3 type) of micellar cylinders. The maximization of free volume entropy is considered as the main driving force for the formation of superlattices, which is well supported by our theoretical free energy calculations. Our approach provides a route for fabricating binary one-dimensional nanoparticle superlattices and may be applicable for inorganic one-dimensional nanoparticle systems.Binary mixtures of 1D particles are rarely observed to cooperatively self-assemble into binary superlattices, as the particle types separate into phases. Here, the authors design a system that avoids phase separation, obtaining binary superlattices with different symmetries by simply tuning the particle diameter and mixture composition.

Simplified conditions holding at the gas-liquid interface during evaporation

NASA Astrophysics Data System (ADS)

Morris, S. J. S.

2017-11-01

We show that on the gas side of the interface between a pure liquid and a binary mixture of its vapour with an insoluble gas, the normal derivative of vapour partial pressure pv satisfies ∂pv/∂n +αc/2 πpD (P -pv) (p -pv) = 0 . Constants α, c, D denote the dimensionless accommodation coefficient, a molecular speed and the diffusivity. Provided the continuum approximation holds within the gas, and α = O(1) , this boundary condition implies that evaporation can take one of two forms. (a) If the coexistence pressure P evaluated at the interface is less than the constant total gas pressure p, liquid at the interface is in local thermodynamic equilibrium with its vapour, and the evaporation rate is determined by diffusion through the gas. (b) Conversely, if P > p , gas at the interface consists of pure vapour, and the evaporation rate is determined by processes within the liquid. In the Wayner theory of the heated evaporating meniscus, such as that in a heat pipe, case (b) is assumed. As an application of our result, we show that some of the published experiments intended to test the Wayner theory instead operate under conditions in which case (a) holds. As a result, they do not perform the test intended.

An analysis of the relaxation of laminar boundary layer on a flat plate after passage of an interface with application to expansion-tube flows

NASA Technical Reports Server (NTRS)

Gupta, R. N.

1972-01-01

The relaxation of the accelerating-gas boundary layer to the test-gas boundary layer over a flat plate in an expansion tube is analyzed. Several combinations of test gas and acceleration gas are considered. The problem is treated in two conically similar limits: (1) when the time lag between the arrival of the shock and the interface at the leading edge of the plate is very large, and (2) when this lag is negligible. The time-dependent laminar-boundary-layer equations of a binary mixture of perfect gases are taken as the flow-governing equations. This coupled set of differential equations, written in terms of the Lam-Crocco variables, has been solved by a line-relaxation finite-difference techniques. The results presented include the Stanton number and the local skin-friction coefficient as functions of shock Mach number and the nondimensional distance-time variable. The results indicate that more than 95 percent of the test-gas boundary layer exists over a length, measured from the leading edge of the plate, equal to about three-tenths of the distance traversed by the interface in the free stream.

Additive and synergistic antiandrogenic activities of mixtures of azol fungicides and vinclozolin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christen, Verena; Crettaz, Pierre; Fent, Karl, E-mail: karl.fent@fhnw.ch

Objective: Many pesticides including pyrethroids and azole fungicides are suspected to have an endocrine disrupting property. At present, the joint activity of compound mixtures is only marginally known. Here we tested the hypothesis that the antiandrogenic activity of mixtures of azole fungicides can be predicted by the concentration addition (CA) model. Methods: The antiandrogenic activity was assessed in MDA-kb2 cells. Following assessing single compounds activities mixtures of azole fungicides and vinclozolin were investigated. Interactions were analyzed by direct comparison between experimental and estimated dose–response curves assuming CA, followed by an analysis by the isobole method and the toxic unit approach.more » Results: The antiandrogenic activity of pyrethroids deltamethrin, cypermethrin, fenvalerate and permethrin was weak, while the azole fungicides tebuconazole, propiconazole, epoxiconazole, econazole and vinclozolin exhibited strong antiandrogenic activity. Ten binary and one ternary mixture combinations of five antiandrogenic fungicides were assessed at equi-effective concentrations of EC{sub 25} and EC{sub 50}. Isoboles indicated that about 50% of the binary mixtures were additive and 50% synergistic. Synergism was even more frequently indicated by the toxic unit approach. Conclusion: Our data lead to the conclusion that interactions in mixtures follow the CA model. However, a surprisingly high percentage of synergistic interactions occurred. Therefore, the mixture activity of antiandrogenic azole fungicides is at least additive. Practice: Mixtures should also be considered for additive antiandrogenic activity in hazard and risk assessment. Implications: Our evaluation provides an appropriate “proof of concept”, but whether it equally translates to in vivo effects should further be investigated. - Highlights: • Humans are exposed to pesticide mixtures such as pyrethroids and azole fungicides. • We assessed the antiandrogenicity of pyrethroids and azole fungizides. • Many azole fungicides showed significant antiandrogenic activity . • Many binary mixtures of antiandrogenic azole fungicides showed synergistic interactions. • Concentration addition of pesticides in mixtures should be considered.« less

Strong cooperative effect of oppositely charged surfactant mixtures on their adsorption and packing at the air-water interface and interfacial water structure.

PubMed

Nguyen, Khoi T; Nguyen, Tuan D; Nguyen, Anh V

2014-06-24

Remarkable adsorption enhancement and packing of dilute mixtures of water-soluble oppositely-charged surfactants, sodium dodecyl sulfate (SDS) and dodecyl amine hydrochloride (DAH), at the air-water interface were observed by using sum frequency generation spectroscopy and tensiometry. The interfacial water structure was also observed to be significantly influenced by the SDS-DAH mixtures, differently from the synergy of the single surfactants. Most strikingly, the obtained spectroscopic evidence suggests that the interfacial hydrophobic alkyl chains of the binary mixtures assemble differently from those of single surfactants. This study highlights the significance of the cooperative interaction between the headgroups of oppositely charged binary surfactant systems and subsequently provides some insightful observations about the molecular structure of the air-aqueous interfacial water molecules and, more importantly, about the packing nature of the surfactant hydrophobic chains of dilute SDS-DAH mixtures of concentration below 1% of the CMC.

Dielectric relaxation and hydrogen bonding interaction in xylitol-water mixtures using time domain reflectometry

NASA Astrophysics Data System (ADS)

Rander, D. N.; Joshi, Y. S.; Kanse, K. S.; Kumbharkhane, A. C.

2016-01-01

The measurements of complex dielectric permittivity of xylitol-water mixtures have been carried out in the frequency range of 10 MHz-30 GHz using a time domain reflectometry technique. Measurements have been done at six temperatures from 0 to 25 °C and at different weight fractions of xylitol (0 < W X ≤ 0.7) in water. There are different models to explain the dielectric relaxation behaviour of binary mixtures, such as Debye, Cole-Cole or Cole-Davidson model. We have observed that the dielectric relaxation behaviour of binary mixtures of xylitol-water can be well described by Cole-Davidson model having an asymmetric distribution of relaxation times. The dielectric parameters such as static dielectric constant and relaxation time for the mixtures have been evaluated. The molecular interaction between xylitol and water molecules is discussed using the Kirkwood correlation factor ( g eff ) and thermodynamic parameter.

Shock tubes and waves; Proceedings of the Thirteenth International Symposium, Niagara Falls, NY, July 6-9, 1981

NASA Astrophysics Data System (ADS)

Treanor, C. E.; Hall, J. G.

1982-10-01

The present conference on shock tubes and waves considers shock tube drivers, luminous shock tubes, shock tube temperature and pressure measurement, shock front distortion in real gases, nonlinear standing waves, transonic flow shock wave turbulent boundary interactions, wall roughness effects on reflected shock bifurcation, argon thermal conductivity, pattern generation in gaseous detonations, cylindrical resonators, shock tunnel-produced high gain lasers, fluid dynamic aspects of laser-metal interaction, and the ionization of argon gas behind reflected shock waves. Also discussed are the ionization relaxation of shock-heated plasmas and gases, discharge flow/shock tube studies of singlet oxygen, rotational and vibrational relaxation, chemiluminescence thermal and shock wave decomposition of hydrogen cyanide and hydrogen azide, shock wave structure in gas-particle mixtures at low Mach numbers, binary nucleation in a Ludwieg tube, shock liquefaction experiments, pipeline explosions, the shock wave ignition of pulverized coal, and shock-initiated methane combustion.

Molecular interactions and structures in ethylene glycol-ethanol and ethylene glycol-water solutions at 303 K on densities, viscosities, and refractive indices data

NASA Astrophysics Data System (ADS)

Deosarkar, S. D.; Ghatbandhe, A. S.

2014-01-01

Molecular interactions and structural fittings in binary ethylene glycol + ethanol (EGE, x EG = 0.4111-0.0418) and ethylene glycol + water (EGW, x EG = 0.1771-0.0133) mixtures were studied through the measurement of densities (ρ), viscosities (η), and refractive indices ( n D ) at 303.15 K. Excess viscosities (η E ), molar volumes ( V m ), excess molar volumes ( V {/m E }), and molar retractions ( R M ) of the both binary systems were computed from measured properties. The measured and computed properties have been used to understand the molecular interactions in unlike solvents and structural fittings in these binary mixtures.

Modeling biofiltration of VOC mixtures under steady-state conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baltzis, B.C.; Wojdyla, S.M.; Zarook, S.M.

1997-06-01

Treatment of air streams contaminated with binary volatile organic compound (VOC) mixtures in classical biofilters under steady-state conditions of operation was described with a general mathematical model. The model accounts for potential kinetic interactions among the pollutants, effects of oxygen availability on biodegradation, and biomass diversification in the filter bed. While the effects of oxygen were always taken into account, two distinct cases were considered for the experimental model validation. The first involves kinetic interactions, but no biomass differentiation, used for describing data from biofiltration of benzene/toluene mixtures. The second case assumes that each pollutant is treated by a differentmore » type of biomass. Each biomass type is assumed to form separate patches of biofilm on the solid packing material, thus kinetic interference does not occur. This model was used for describing biofiltration of ethanol/butanol mixtures. Experiments were performed with classical biofilters packed with mixtures of peat moss and perlite (2:3, volume:volume). The model equations were solved through the use of computer codes based on the fourth-order Runge-Kutta technique for the gas-phase mass balances and the method of orthogonal collocation for the concentration profiles in the biofilms. Good agreement between model predictions and experimental data was found in almost all cases. Oxygen was found to be extremely important in the case of polar VOCs (ethanol/butanol).« less

Dielectric properties of benzylamine in 1,2,6-hexanetriol mixture using time domain reflectometry technique

NASA Astrophysics Data System (ADS)

Swami, M. B.; Hudge, P. G.; Pawar, V. P.

The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry (TDR) technique in the frequency range of 10 MHz to 30 GHz. Complex permittivity spectra were fitted using Havriliak-Negami equation. By using least square fit method the dielectric parameters such as static dielectric constant (ɛ0), dielectric constant at high frequency (ɛ∞), relaxation time τ (ps) and relaxation distribution parameter (β) were extracted from complex permittivity spectra at 25∘C. The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor, Bruggeman factor. The Kirkwood correlation factor (gf) and effective Kirkwood correlation factor (geff) indicate the dipole ordering of the binary mixtures.

Metastable liquid lamellar structures in binary and ternary mixtures of Lennard-Jones fluids

NASA Astrophysics Data System (ADS)

Díaz-Herrera, Enrique; Ramírez-Santiago, Guillermo; Moreno Razo, José A.

2004-03-01

We have carried out extensive equilibrium MD simulations to investigate the Liquid-Vapor coexistence in partially miscible binary and ternary mixtures LJ fluids. We have studied in detail the time evolution of the density profiles and the interfacial properties in a temperature region of the phase diagram where the condensed phase is demixed. The composition of the mixtures are fixed, 50% for the binary mixture and 33.33% for the ternary mixture. The results of the simulations clearly indicate that in the range of temperatures 78 < T < 102 ^oK,--in the scale of argon-- the system evolves towards a metastable alternated liquid-liquid lamellar state in coexistence with its vapor phase. These states can be achieved if the initial configuration is fully disordered, that is, when the particles of the fluids are randomly placed on the sites of an FCC crystal or the system is completely mixed. As temperature decreases these states become very well defined and more stable in time. We find that below 90 ^oK, the alternated liquid-liquid lamellar state remains alive for 80 ns, in the scale of argon, the longest simulation we have carried out. Nonetheless, we believe that in this temperature region these states will be alive for even much longer times.

Birthdays and the Binary System: A Magical Mixture.

ERIC Educational Resources Information Center

Karp, Karen S.; Ronau, Robert N.

1997-01-01

Presents an activity involving the use of students' birth dates. Activity includes a classic binary representation of numerical values. In the Green Machine, Sorting Cards, and Window Cards, students observe, describe, and analyze patterns. (PVD)

Improving Students' Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

ERIC Educational Resources Information Center

Privat, Romain; Jaubert, Jean-Noël; Moine, Edouard

2016-01-01

In many textbooks of chemical-engineering thermodynamics, a gas mixture obeying the fundamental law pV[subscript m] = RT is most often called ideal-gas mixture (in some rare cases, the term perfect-gas mixture can be found). These textbooks also define the fundamental concept of ideal solution which in theory, can be applied indifferently to…

On studies of 3He and isobutane mixture as neutron proportional counter gas

NASA Astrophysics Data System (ADS)

Desai, S. S.; Shaikh, A. M.

2006-02-01

The performance of neutron detectors filled with 3He+iC 4H 10 (isobutane) gas mixtures has been studied and compared with the performance of detectors filled with 3He+Kr gas mixtures. The investigations are made to determine suitable concentration of isobutane in the gas mixture to design neutron proportional counters and linear position sensitive neutron detectors (1-D PSDs). Energy resolution, range of proportionality, plateau and gas gain characteristics are studied for various gas mixtures of 3He and isobutane. The values for various gas constants are determined by fitting the gas gains to Diethorn and Bateman's equations and their variation with isobutane concentration in the fill gas mixture is studied.

QSAR prediction of additive and non-additive mixture toxicities of antibiotics and pesticide.

PubMed

Qin, Li-Tang; Chen, Yu-Han; Zhang, Xin; Mo, Ling-Yun; Zeng, Hong-Hu; Liang, Yan-Peng

2018-05-01

Antibiotics and pesticides may exist as a mixture in real environment. The combined effect of mixture can either be additive or non-additive (synergism and antagonism). However, no effective predictive approach exists on predicting the synergistic and antagonistic toxicities of mixtures. In this study, we developed a quantitative structure-activity relationship (QSAR) model for the toxicities (half effect concentration, EC 50 ) of 45 binary and multi-component mixtures composed of two antibiotics and four pesticides. The acute toxicities of single compound and mixtures toward Aliivibrio fischeri were tested. A genetic algorithm was used to obtain the optimized model with three theoretical descriptors. Various internal and external validation techniques indicated that the coefficient of determination of 0.9366 and root mean square error of 0.1345 for the QSAR model predicted that 45 mixture toxicities presented additive, synergistic, and antagonistic effects. Compared with the traditional concentration additive and independent action models, the QSAR model exhibited an advantage in predicting mixture toxicity. Thus, the presented approach may be able to fill the gaps in predicting non-additive toxicities of binary and multi-component mixtures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pycnonuclear reaction rates for binary ionic mixtures

NASA Technical Reports Server (NTRS)

Ichimaru, S.; Ogata, S.; Van Horn, H. M.

1992-01-01

Through a combination of compositional scaling arguments and examinations of Monte Carlo simulation results for the interparticle separations in binary-ionic mixture (BIM) solids, we have derived parameterized expressions for the BIM pycnonuclear rates as generalizations of those in one-component solids obtained previously by Salpeter and Van Horn and by Ogata et al. We have thereby discovered a catalyzing effect of the heavier elements, which enhances the rates of reactions among the lighter elements when the charge ratio exceeds a critical value of approximately 2.3.

Solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, propylene glycol, N-methyl-2-pyrrolidone, and water at 25 degrees C.

PubMed

Jouyban, Abolghasem; Soltanpour, Shahla

2010-09-01

The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 degrees C are reported. The generated data are fitted to the Jouyban-Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

Instability of a solidifying binary mixture

NASA Technical Reports Server (NTRS)

Antar, B. N.

1982-01-01

An analysis is performed on the stability of a solidifying binary mixture due to surface tension variation of the free liquid surface. The basic state solution is obtained numerically as a nonstationary function of time. Due to the time dependence of the basic state, the stability analysis is of the global type which utilizes a variational technique. Also due to the fact that the basic state is a complex function of both space and time, the stability analysis is performed through numerical means.

Soret motion in non-ionic binary molecular mixtures

NASA Astrophysics Data System (ADS)

Leroyer, Yves; Würger, Alois

2011-08-01

We study the Soret coefficient of binary molecular mixtures with dispersion forces. Relying on standard transport theory for liquids, we derive explicit expressions for the thermophoretic mobility and the Soret coefficient. Their sign depends on composition, the size ratio of the two species, and the ratio of Hamaker constants. Our results account for several features observed in experiment, such as a linear variation with the composition; they confirm the general rule that small molecules migrate to the warm, and large ones to the cold.

Fiber Supported Droplet Combustion-2 (FSDC-2)

NASA Technical Reports Server (NTRS)

Colantonio, Renato; Dietrich, Daniel; Haggard, John B., Jr.; Nayagan, Vedha; Dryer, Frederick L.; Shaw, Benjamin D.; Williams, Forman A.

1998-01-01

Experimental results for the burning characteristics of fiber supported, liquid droplets in ambient Shuttle cabin air (21% oxygen, 1 bar pressure) were obtained from the Glove Box Facility aboard the STS-94/MSL-1 mission using the Fiber Supported Droplet Combustion - 2 (FSDC-2) apparatus. The combustion of individual droplets of methanol/water mixtures, ethanol, ethanol/water azeotrope, n-heptane, n-decane, and n-heptane/n-hexadecane mixtures were studied in quiescent air. The effects of low velocity, laminar gas phase forced convection on the combustion of individual droplets of n-heptane and n-decane were investigated and interactions of two droplet-arrays of n-heptane and n-decane droplets were also studied with and without gas phase convective flow. Initial diameters ranging from about 2mm to over 6mm were burned on 80-100 micron silicon fibers. In addition to phenomenological observations, quantitative data were obtained in the form of backlit images of the burning droplets, overall flame images, and radiometric combustion emission measurements as a function of the burning time in each experiment. In all, 124 of the 129 attempted experiments (or about twice the number of experiments originally planned for the STS-94/MSL-1 mission) were conducted successfully. The experimental results contribute new observations on the combustion properties of pure alkanes, binary alkane mixtures, and simple alcohols for droplet sizes not studied previously, including measurements on individual droplets and two-droplet arrays, inclusive of the effects of forced gas phase convection. New phenomena characterized experimentally for the first time include radiative extinction of droplet burning for alkanes and the "twin effect" which occurs as a result of interactions during the combustion of two-droplet arrays. Numerical modeling of isolated droplet combustion phenomenon has been conducted for methanol/water mixtures, n-heptane, and n-heptane/n-hexadecane mixtures, and results compare quantitatively with those found experimentally for methanol/water mixtures. Initial computational results qualitatively predict experimental results obtained for isolated n-heptane and n-heptane/n-hexadecane droplet combustion, although the effects of sooting are not yet included in the modeling work. Numerical modeling of ethanol and ethanol/water droplet burning is under development. Considerable data remain to be fully analyzed and will provide a large database for comparisons with further numerical and analytical modeling and development of future free droplet experiments aboard space platforms.

A Novel Approach for Evaluating Carbamate Mixtures for Dose Additivity

EPA Science Inventory

Two mathematical approaches were used to test the hypothesis ofdose-addition for a binary and a seven-chemical mixture ofN-methyl carbamates, toxicologically similar chemicals that inhibit cholinesterase (ChE). In the more novel approach, mixture data were not included in the ana...

Grafting of vinyl acetate-ethylacrylate binary monomer mixture onto guar gum.

PubMed

Singh, Vandana; Singh, Angela; Joshi, Sneha; Malviya, Tulika

2016-03-01

Present article reports on guar gum (GG) functionalization through graftcopolymerization of vinylacetate (VAC) and ethylacrylate (EA) from their binary mixtures. The potassium persulfate/ascorbic acid (KPS/AA) redox initiator system has been used for the binary grafting under the previously optimized conditions for VAC grafting at guar gum. The concentration of ascorbic acid (AA), persulfate (KPS), and grafting temperature were varied to optimize the binary grafting. A preliminary investigation revealed that the copolymer has excellent ability to capture Hg(II) from aqueous solution. It was observed that the optimum % grafting sample (CP3) was best at Hg(II) adsorption. CP3 and mercury loaded CP3 (CP3-Hg) have been extensively characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Thermo gravimetric analysis (TGA) and a plausible mechanism for the grafting has been proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution of short block copolymer chains in Binary Blends of Block Copolymers Having Hydrogen Bonding

NASA Astrophysics Data System (ADS)

Kwak, Jongheon; Han, Sunghyun; Kim, Jin Kon

2014-03-01

A binary mixture of two block copolymers whose blocks are capable of forming the hydrogen bonding allows one to obtain various microdomains that could not be expected for neat block copolymer. For instance, the binary blend of symmetric polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) and polystyrene-block-polyhydroxystyrene copolymer (PS-b-PHS) blends where the hydrogen bonding occurred between P2VP and PHS showed hexagonally packed (HEX) cylindrical and body centered cubic (BCC) spherical microdomains. To know the exact location of short block copolymer chains at the interface, we synthesized deuterated polystyrene-block-polyhydroxystyrene copolymer (dPS-b-PHS) and prepared a binary mixture with PS-b-P2VP. We investigate, via small angle X-ray scattering (SAXS) and neutron reflectivity (NR), the exact location of shorter dPS block chain near the interface of the microdomains.

Measuring Parameters of Massive Black Hole Binaries with Partially-Aligned Spins

NASA Technical Reports Server (NTRS)

Lang, Ryan N.; Hughes, Scott A.; Cornish, Neil J.

2010-01-01

It is important to understand how well the gravitational-wave observatory LISA can measure parameters of massive black hole binaries. It has been shown that including spin precession in the waveform breaks degeneracies and produces smaller expected parameter errors than a simpler, precession-free analysis. However, recent work has shown that gas in binaries can partially align the spins with the orbital angular momentum, thus reducing the precession effect. We show how this degrades the earlier results, producing more pessimistic errors in gaseous mergers. However, we then add higher harmonics to the signal model; these also break degeneracies, but they are not affected by the presence of gas. The harmonics often restore the errors in partially-aligned binaries to the same as, or better than/ those that are obtained for fully precessing binaries with no harmonics. Finally, we investigate what LISA measurements of spin alignment can tell us about the nature of gas around a binary,

Porous materials as high performance adsorbents for CO2 capture, gas separation and purification

NASA Astrophysics Data System (ADS)

Wang, Jun

Global warming resulted from greenhouse gases emission has received a widespread attention. Among the greenhouse gases, CO2 contributes more than 60% to global warming due to its huge emission amount. The flue gas contains about 15% CO2 with N2 as the balance. If CO2 can be separated from flue gas, the benefit is not only reducing the global warming effect, but also producing pure CO2 as a very useful industry raw material. Substantial progress is urgent to be achieved in an industrial process. Moreover, energy crisis is one of the biggest challenges for all countries due to the short life of fossil fuels, such as, petroleum will run out in 50 years and coal will run out in 150 years according to today's speed. Moreover, the severe pollution to the environment caused by burning fossil fuels requires us to explore sustainable, environment-friendly, and facile energy sources. Among several alternative energy sources, natural gas is one of the most promising alternative energy sources due to its huge productivity, abundant feed stock, and ease of generation. In order to realize a substantial adsorption process in industry, synthesis of new adsorbents or modification of existing adsorbent with improved properties has become the most critical issue. This dissertation reports systemic characterization and development of five serials of novel adsorbents with advanced adsorption properties. In chapter 2, nitrogen-doped Hypercross-linking Polymers (HCPs) have been synthesized successfully with non-carcinogenic chloromethyl methyl ether (CME) as the cross-linking agent within a single step. Texture properties, surface morphology, CO2/N2 selectivity, and adsorption heat have been presented and demonstrated properly. A comprehensive discussion on factors that affect the CO2 adsorption and CO2/N 2 separation has also been presented. It was found that high micropore proportion and N-content could effectively enhance CO2 uptake and CO2/N2 separation selectivity. In chapter 3, a new series of oxygen-doped ACs were synthesized from polyfuran. Different factors that affect the AC formation were investigated, and two kinds of porogens (ZnC12 and KOH) and two active temperatures (600 and 800 °C) were tested. At 298K and 1bar, an excellent selectivity for separating CO2/N2 (41.7) and CO2/CH 4(6.8) gas mixture pairs was obtained on the PF-600 KOH. A breakthrough simulation was also performed to demonstrate the potential of industrial applications. The PF-600 KOH sample showed the best separation result in the simulated adsorption breakthrough as well. In chapter 4, quinone and hydroquinone on the surface of PF-600 ZnC1 2 were integrated. Significantly pore size shrinkage, improved CO 2/N2 and CO2/CH4 IAST selectivity were observed, which is 58.7% and 28.4 % higher than pristine porous carbon at 298K and 1 atm, respectively. In addition, transient breakthrough simulations for CO2/CH4/N2 binary mixtures were conducted in order to demonstrate the good separation performance in fixed bed adsorbers. In chapter 5, a novel nitrogen doped polymer poly(2-phenyl-1,3,6,8tetraazacyclodecane) will be used as the precursor to produce microporous N-doped activated carbons. Three activation temperatures (600, 700, and 800 °C) has been investigated with KOH as the porogen. High nitrogen content has been remained in the resultant carbon materials. Improved CO2 adsorption capacity and selectivites for the separation of CO2/CH4/N2 binary gas mixtures were achieved by the carbon adsorbents due to their N-containing groups, narrow pore size distribution, and large specific surface area. In chapter 6, MOF-derived activated carbons are developed from MIL-100(Al) as hard-template. Direct carbonization of MIL-100, MIL-100(Al)/F-127 composite, and MIL-100(Al)/KOH mixture has been investigated. Pore structure and surface morphology have been demonstrated. CO2/CH4/N2 binary selectivity, adsorption heats, and kinetic selectivity have been calculated. Breakthrough simulation has been conducted to mimic industrial application. We found that resultant carbons showed better CO2 capture ability and selectivity than parental MIL-100(Al).

Dielectric and conformational studies of hydrogen bonded 2-ethoxyethanol and ethyl methyl ketone system

NASA Astrophysics Data System (ADS)

Pattebahadur, Kanchan. L.; Deshmukh, S. D.; Mohod, A. G.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

2018-05-01

The Dielectric constant, density and refractive index of binary mixture of 2-ethoxy ethanol (2-EE) with ethyl methyl ketone (EMK) including those of the pure liquids were measured for 11 concentrations at 25°C temperature. The experimental data is used to calculate the Excess molar volume, Excess dielectric constant, Kirkwood correlation factor and Bruggemann factor. The excess parameters results were fitted to the Redlich-Kister type polynomial equation to derive its fitting coefficient. The Kirkwood correlation factor of the mixture has been discussed to yield information about solute solvent interaction. The Bruggeman plot shows a deviation from linearity. The FT-IR spectra of pure and their binary mixtures are also studied.

Domain wall suppression in trapped mixtures of Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Pepe, Francesco V.; Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio

2012-08-01

The ground-state energy of a binary mixture of Bose-Einstein condensates can be estimated for large atomic samples by making use of suitably regularized Thomas-Fermi density profiles. By exploiting a variational method on the trial densities the energy can be computed by explicitly taking into account the normalization condition. This yields analytical results and provides the basis for further improvement of the approximation. As a case study, we consider a binary mixture of 87Rb atoms in two different hyperfine states in a double-well potential and discuss the energy crossing between density profiles with different numbers of domain walls, as the number of particles and the interspecies interaction vary.

Thermophysical properties of N, N-dimethylacetamide mixtures with n-butanol

NASA Astrophysics Data System (ADS)

Maharolkar, Aruna P.; Murugkar, A. G.; Khirade, P. W.; Mehrotra, S. C.

2017-09-01

The refraction, dielectric, viscosity, density, data of the binary mixtures of N, N-dimethylacetamide (DMA) with n-butanol at 308.15 and 313.15 K. The measured parameters used to obtain derived properties like Bruggeman factor, molar refraction and excess static dielectric constant, excess inverse relaxation time, excess molar volume and excess viscosity, excess molar refraction. The variation in magnitude with composition and temperature of these quantities has been used to discuss the type, strength and nature of binary interactions. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of DMA+ n-butanol mixtures and that 1: 1 complexes are formed and strength of intermolecular interaction increases with temperature.

Fragility and glass transition for binary mixtures of 1,2-propanediol and LiBF4

NASA Astrophysics Data System (ADS)

Terashima, Y.; Mori, M.; Sugimoto, N.; Takeda, K.

2014-04-01

The fragility and glass transition for binary mixtures of 1,2-propanediol and LiBF4 were investigated by measuring the heating rate dependence of glass transition temperature (Tg) using differential scanning calorimetry. With increasing LiBF4 mole fraction, x, up to 0.25, fragility, m, increased rapidly from 53 to 85, and then remained approximately unchanged for x > 0.25. The concentration dependences of Tg and heat capacity jump at Tg also showed anomalies around x = 0.25. We suggest this mixture transformed from a moderate to quite fragile liquid at x = 0.25 because of a structural change from a hydrogen-bonding- to ionic-interaction-dominant system.

Dynamics of dense granular flows of small-and-large-grain mixtures in an ambient fluid.

PubMed

Meruane, C; Tamburrino, A; Roche, O

2012-08-01

Dense grain flows in nature consist of a mixture of solid constituents that are immersed in an ambient fluid. In order to obtain a good representation of these flows, the interaction mechanisms between the different constituents of the mixture should be considered. In this article, we study the dynamics of a dense granular flow composed of a binary mixture of small and large grains immersed in an ambient fluid. In this context, we extend the two-phase approach proposed by Meruane et al. [J. Fluid Mech. 648, 381 (2010)] to the case of flowing dense binary mixtures of solid particles, by including in the momentum equations a constitutive relation that describes the interaction mechanisms between the solid constituents in a dense regime. These coupled equations are solved numerically and validated by comparing the numerical results with experimental measurements of the front speed of gravitational granular flows resulting from the collapse, in ambient air or water, of two-dimensional granular columns that consisted of mixtures of small and large spherical particles of equal mass density. Our results suggest that the model equations include the essential features that describe the dynamics of grains flows of binary mixtures in an ambient fluid. In particular, it is shown that segregation of small and large grains can increase the front speed because of the volumetric expansion of the flow. This increase in flow speed is damped by the interaction forces with the ambient fluid, and this behavior is more pronounced in water than in air.

The effects of binary UV filter mixtures on the midge Chironomus riparius.

PubMed

Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

2016-06-15

Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. Copyright © 2016 Elsevier B.V. All rights reserved.

Theoretical Investigation of the Process of Steam-Oxygen Gasification of Coke-Ash Particles in a Fluidized Bed Under Pressure

NASA Astrophysics Data System (ADS)

Rokhman, B. B.

2015-03-01

The problem on the evolution of the state of an ensemble of reacting coke-ash particles in a fluidized-bed gas generator is considered. A kinetic equation for the distribution function of particles within small ranges of carbon concentration variation for the stages of surface and bulk reaction has been constructed and integrated. Boundary conditions ("matching" conditions) at the boundaries between these ranges are formulated. The influence of the granulometric composition of the starting coal, height, porosity, and of the bed temperature on the process of steam-oxygen gasification of coke-ash particles of individual sorts of fuel and of a binary coal mixture has been investigated.

METALLURGICAL PROGRAMS: CALCULATION OF MASS FROM VOLUME, DENSITY OF MIXTURES, AND CONVERSION OF ATOMIC TO WEIGHT PERCENT

NASA Technical Reports Server (NTRS)

Degroh, H.

1994-01-01

The Metallurgical Programs include three simple programs which calculate solutions to problems common to metallurgical engineers and persons making metal castings. The first program calculates the mass of a binary ideal (alloy) given the weight fractions and densities of the pure components and the total volume. The second program calculates the densities of a binary ideal mixture. The third program converts the atomic percentages of a binary mixture to weight percentages. The programs use simple equations to assist the materials staff with routine calculations. The Metallurgical Programs are written in Microsoft QuickBASIC for interactive execution and have been implemented on an IBM PC-XT/AT operating MS-DOS 2.1 or higher with 256K bytes of memory. All instructions needed by the user appear as prompts as the software is used. Data is input using the keyboard only and output is via the monitor. The Metallurgical programs were written in 1987.

Refractive index, molar refraction and comparative refractive index study of propylene carbonate binary liquid mixtures.

PubMed

Wankhede, Dnyaneshwar Shamrao

2012-06-01

Refractive indices (n) have been experimentally determined for the binary liquid-liquid mixtures of Propylene carbonate (PC) (1) with benzene, ethylbenzene, o-xylene and p-xylene (2) at 298.15, 303.15 and 308.15 K over the entire mole fraction range. The experimental values of n are utilised to calculate deviation in refractive index (Δn), molar refraction (R) and deviation in molar refraction (ΔR). A comparative study of Arago-Biot (A-B), Newton (NW), Eyring and John (E-J) equations for determining refractive index of a liquid has been carried out to test their validity for all the binary mixtures over the entire composition range at 298.15 K. Comparison of various mixing relations is represented in terms of average deviation (AVD). The Δn and ΔR values have been fitted to Redlich-Kister equation at 298.15 K and standard deviations have been calculated. The results are discussed in terms of intermolecular interactions present amongst the components.

Physical compatibility of binary and ternary mixtures of morphine and methadone with other drugs for parenteral administration in palliative care.

PubMed

Destro, Massimo; Ottolini, Luca; Vicentini, Lorenza; Boschetti, Silvia

2012-10-01

The parenteral administration of combinations of drugs is often necessary in palliative medicine, particularly in the terminal stage of life, when patients are no longer able to take medication orally. The use of infusers to administer continuous subcutaneous infusions is a well-established practice in the palliative care setting and enables several drugs to be given simultaneously, avoiding the need for repeated administrations and the effects of peaks and troughs in the doses of medication. The method is also appreciated by patients and caregivers in the home care setting because the devices and infusion sites are easy to manage. Despite their frequent use, however, the mixtures of drugs adopted in clinical practice are sometimes not supported by reliable data concerning their chemical and physical compatibility. The present study investigates the chemical compatibility of binary mixtures (morphine with ketorolac) and the physical compatibility of binary (morphine or methadone with ketorolac) or ternary mixtures (morphine with ketorolac and/or haloperidol, and/or dexamethasone, and/or metoclopramide, and/or hyoscine butylbromide) with a view to reducing the aleatory nature of the empirical use of such combinations, thereby increasing their safety and clinical appropriateness.

Lubrication model for evaporation of binary sessile drops

NASA Astrophysics Data System (ADS)

Williams, Adam; Sáenz, Pedro; Karapetsas, George; Matar, Omar; Sefiane, Khellil; Valluri, Prashant

2017-11-01

Evaporation of a binary mixture sessile drop from a solid substrate is a highly dynamic and complex process with flow driven both thermal and solutal Marangoni stresses. Experiments on ethanol/water drops have identified chaotic regimes on both the surface and interior of the droplet, while mixture composition has also been seen to govern drop wettability. Using a lubrication-type approach, we present a finite element model for the evaporation of an axisymmetric binary drop deposited on a heated substrate. We consider a thin drop with a moving contact line, taking also into account the commonly ignored effects of inertia which drives interfacial instability. We derive evolution equations for the film height, the temperature and the concentration field considering that the mixture comprises two ideally mixed volatile components with a surface tension linearly dependent on both temperature and concentration. The properties of the mixture such as viscosity also vary locally with concentration. We explore the parameter space to examine the resultant effects on wetting and evaporation where we find qualitative agreement with experiments in both these areas. This enables us to understand the nature of the instabilities that spontaneously emerge over the drop lifetime. EPSRC - EP/K00963X/1.

Laboratory Studies of Aedes aegypti Attraction to Ketones, Sulfides, and Primary Chloroalkanes Tested Alone and in Combination with L-Lactic Acid.

PubMed

Bernier, Ulrich R; Kline, Daniel L; Allan, Sandra A; Barnard, Donald R

2015-03-01

The attraction of female Aedes aegypti to single compounds and binary compositions containing L-lactic acid and an additional saturated compound from a set of ketones, sulfides, and chloroalkanes was studied using a triple-cage dual-port olfactometer. These chemical classes were studied because of their structural relation to acetone, dimethyl disulfide, and dichloromethane, which have all been reported to synergize attraction to L-lactic acid. Human odors, carbon dioxide, and the binary mixture of L-lactic acid and CO₂served as controls for comparison of attraction responses produced by the binary mixtures. All tested mixtures that contained chloroalkanes attracted mosquitoes at synergistic levels, as did L-lactic acid and CO₂. Synergism was less frequent in mixtures of L-lactic acid with sulfides and ketones; in the case of ketones, synergistic attraction was observed only for L-lactic acid combined with acetone or butanone. Suppression or inhibition of attraction response was observed for combinations that contained ketones of C7-C12 molecular chain length (optimum in the C8-C10 range). This inhibition effect is similar to that observed previously for specific ranges of carboxylic acids, aldehydes, and alcohols.

Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

DOEpatents

Aines, Roger D.; Bourcier, William L.; Viani, Brian

2013-01-29

A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

Adsorption of CO₂, CH₄, and N₂ on ordered mesoporous carbon: approach for greenhouse gases capture and biogas upgrading.

PubMed

Yuan, Bin; Wu, Xiaofei; Chen, Yingxi; Huang, Jianhan; Luo, Hongmei; Deng, Shuguang

2013-05-21

Separation of CO₂ and N₂ from CH₄ is significantly important in natural gas upgrading, and capture/removal of CO₂, CH₄ from air (N₂) is essential to greenhouse gas emission control. Adsorption equilibrium and kinetics of CO₂, CH₄, and N₂ on an ordered mesoporous carbon (OMC) sample were systematically investigated to evaluate its capability in the above two applications. The OMC was synthesized and characterized with TEM, TGA, small-angle XRD, and nitrogen adsorption/desorption measurements. Pure component adsorption isotherms of CO₂, CH₄, and N₂ were measured at 278, 298, and 318 K and pressures up to 100 kPa, and correlated with the Langmuir model. These data were used to estimate the separation selectivities for CO₂/CH₄, CH₄/N₂, and CO₂/N₂ binary mixtures at different compositions and pressures according to the ideal adsorbed solution theory (IAST) model. At 278 K and 100 kPa, the predicted selectivities for equimolar CO₂/CH₄, CH4/N₂, and CO₂/N₂ are 3.4, 3.7, and 12.8, respectively; and the adsorption capacities for CH₄ and CO₂ are 1.3 and 3.0 mmol/g, respectively. This is the first report of a versatile mesoporous material that displays both high selectivities and large adsorption capacities for separating CO₂/CH₄, CH₄/N₂, and CO₂/N₂ mixtures.

Molecular dynamics study of polysaccharides in binary solvent mixtures of an ionic liquid and water.

PubMed

Liu, Hanbin; Sale, Kenneth L; Simmons, Blake A; Singh, Seema

2011-09-01

Some ionic liquids (ILs) have great promise as effective solvents for biomass pretreatment, and there are several that have been reported that can dissolve large amounts of cellulose. The solubilized cellulose can then be recovered by addition of antisolvents, such as water or ethanol, and this regeneration process plays an important role in the subsequent enzymatic saccharification reactions and in the recovery of the ionic liquid. To date, little is known about the fundamental intermolecular interactions that drive the dissolution and subsequent regeneration of cellulose in complex mixtures of ionic liquids, water, and cellulose. To investigate these interactions, in this work, molecular dynamics (MD) simulations were carried out to study binary and ternary mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) with water and a cellulose oligomer. Simulations of a cellulose oligomer dissolved in three concentrations of binary mixtures of [C2mim][OAc] and water were used to represent the ternary system in the dissolution phase (high [C2mim][OAc] concentration) and present during the initial phase of the regeneration step (intermediate and low [C2mim][OAc] concentrations). The MD analysis of the structure and dynamics that exist in these binary and ternary mixtures provides information on the key intermolecular interactions between cellulose and [C2mim][OAc] that lead to dissolution of cellulose and the key intermolecular interactions in the intermediate states of cellulose precipitation as a function of water content in the cellulose/IL/water system. The analysis of this intermediate state provides new insight into the molecular driving forces present in this ternary system. © 2011 American Chemical Society

The onset of convection in a binary fluid mixture with temperature dependent viscosity and Coriolis force with Soret presence

NASA Astrophysics Data System (ADS)

Abidin, Nurul Hafizah Zainal; Mokhtar, Nor Fadzillah Mohd; Majid, Zanariah Abdul; Ghani, Siti Salwa Abd

2017-11-01

Temperature dependent viscosity and Coriolis force were applied to the steady Benard-Marangoni convection where the lower boundary of a horizontal layer of the binary mixture is heated from below and cooled from above. The purpose of this paper is to study in detail the onset of convection with these effects. Few cases of boundary conditions are studied which are rigid-rigid, rigid-free and free-free representing the lower-upper boundaries. A detailed numerical calculation of the marginal stability curves was performed by using the Galerkin method and it is showed that temperature dependent viscosity and Soret number destabilize the binary fluid layer system and Taylor number act oppositely.

Quantitative measurement of indomethacin crystallinity in indomethacin-silica gel binary system using differential scanning calorimetry and X-ray powder diffractometry.

PubMed

Pan, Xiaohong; Julian, Thomas; Augsburger, Larry

2006-02-10

Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) methods were developed for the quantitative analysis of the crystallinity of indomethacin (IMC) in IMC and silica gel (SG) binary system. The DSC calibration curve exhibited better linearity than that of XRPD. No phase transformation occurred in the IMC-SG mixtures during DSC measurement. The major sources of error in DSC measurements were inhomogeneous mixing and sampling. Analyzing the amount of IMC in the mixtures using high-performance liquid chromatography (HPLC) could reduce the sampling error. DSC demonstrated greater sensitivity and had less variation in measurement than XRPD in quantifying crystalline IMC in the IMC-SG binary system.

Improved wire chamber

DOEpatents

Atac, M.

1987-05-12

An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.

Picosecond solvation dynamics—A potential viewer of DMSO—Water binary mixtures

NASA Astrophysics Data System (ADS)

Banik, Debasis; Kundu, Niloy; Kuchlyan, Jagannath; Roy, Arpita; Banerjee, Chiranjib; Ghosh, Surajit; Sarkar, Nilmoni

2015-02-01

In this work, we have investigated the composition dependent anomalous behavior of dimethyl sulfoxide (DMSO)-water binary mixture by collecting the ultrafast solvent relaxation response around a well known solvation probe Coumarin 480 (C480) by using a femtosecond fluorescence up-conversion spectrometer. Recent molecular dynamics simulations have predicted two anomalous regions of DMSO-water binary mixture. Particularly, these studies encourage us to investigate the anomalies from experimental background. DMSO-water binary mixture has repeatedly given evidences of its dual anomalous nature in front of our systematic investigation through steady-state and time-resolved measurements. We have calculated average solvation times of C480 by two individual well-known methods, among them first one is spectral-reconstruction method and another one is single-wavelength measurement method. The results of both the methods roughly indicate that solvation time of C480 reaches maxima in the mole fraction of DMSO XD = 0.12-0.17 and XD = 0.27-0.35, respectively. Among them, the second region (XD = 0.27-0.35) is very common as most of the thermodynamic properties exhibit deviation in this range. Most probably, the anomalous solvation trend in this region is fully guided by the shear viscosity of the medium. However, the first region is the most interesting one. In this region due to formation of strongly hydrogen bonded 1DMSO:2H2O complexes, hydration around the probe C480 decreases, as a result of which solvation time increases.

Dielectric Studies on Binary Mixtures of Diethyl Ether (DEE) in Polar Solvents

NASA Astrophysics Data System (ADS)

Pradhan, S. K.; Dash, S. K.; Swain, M. D.; Swain, B. B.

2011-11-01

Dielectric constant (ɛ) of diethylether (DEE) in binary mixtures with four polar solvents such as n-butanl, i-butanol, t-butanol and tolune has been measured at 455 kHz and at a temperature 303.15 K. The refractive indices were measured at a regulated temperature by Pulfrich refractometer at sodium D-line. The data is used to evaluate mutual correlation factor gab, excess molar polarization and excess free energy of mixing ΔGab by using Winkelmann-Quitzsch equation for binary mixtures to asses the suitability of the polar solvents as modifiers. The trend of variation for these parameters exhibit marked dependence on the nature of alcohols. Diethylether is one of the solvent extractant used for the extraction and separation of zirconium and hafnium in reactor technology. The extractant is blended with appropriate polar modifiers for greater dispersal and more rapid phase disengagement. This facilitates in the elimination of the third organo-aqueous phase containing some of the metal ions. As such the study of molecular interaction among the component molecules has been undertaken in these binary mixtures using the dielectric route. The interaction parameters such as mutual correlation factor gab is found to be less than one in all alcohols, while it is negative in toluene upto 0.7 DEE molefraction and thereafter becoming positive. The nature of variation of the excess miolar polarization ΔP and excess free energy of mixing Gab tends to support the assessment of gab to choose a suitable polar modifier.

An analytical solubility model for nitrogen-methane-ethane ternary mixtures

NASA Astrophysics Data System (ADS)

Hartwig, Jason; Meyerhofer, Peter; Lorenz, Ralph; Lemmon, Eric

2018-01-01

Saturn's moon Titan has surface liquids of liquid hydrocarbons and a thick, cold, nitrogen atmosphere, and is a target for future exploration. Critical to the design and operation of vehicles for this environment is knowledge of the amount of dissolved nitrogen gas within the cryogenic liquid methane and ethane seas. This paper rigorously reviews experimental data on the vapor-liquid equilibrium of nitrogen/methane/ethane mixtures, noting the possibility for split liquid phases, and presents simple analytical models for conveniently predicting solubility of nitrogen in pure liquid ethane, pure liquid methane, and a mixture of liquid ethane and methane. Model coefficients are fit to three temperature ranges near the critical point, intermediate range, and near the freezing point to permit accurate predictions across the full range of thermodynamic conditions. The models are validated against the consolidated database of 2356 experimental data points, with mean absolute error between data and model less than 8% for both binary nitrogen/methane and nitrogen/ethane systems, and less than 17% for the ternary nitrogen/methane/ethane system. The model can be used to predict the mole fractions of ethane, methane, and nitrogen as a function of location within the Titan seas.

Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jarvis, Ian W.H., E-mail: Ian.Jarvis@ki.se; Bergvall, Christoffer, E-mail: Christoffer.Bergvall@anchem.su.se; Bottai, Matteo, E-mail: Matteo.Bottai@ki.se

2013-02-01

Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNAmore » damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.« less

Sustained induction of cytochrome P4501A1 in human hepatoma cells by co-exposure to benzo[a]pyrene and 7H-dibenzo[c,g]carbazole underlies the synergistic effects on DNA adduct formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gábelová, Alena, E-mail: alena.gabelova@savba.sk; Poláková, Veronika; Prochazka, Gabriela

To gain a deeper insight into the potential interactions between individual aromatic hydrocarbons in a mixture, several benzo[a]pyrene (B[a]P) and 7H-dibenzo[c,g]carbazole (DBC) binary mixtures were studied. The biological activity of the binary mixtures was investigated in the HepG2 and WB-F344 liver cell lines and the Chinese hamster V79 cell line that stably expresses the human cytochrome P4501A1 (hCYP1A1). In the V79 cells, binary mixtures, in contrast to individual carcinogens, caused a significant decrease in the levels of micronuclei, DNA adducts and gene mutations, but not in cell survival. Similarly, a lower frequency of micronuclei and levels of DNA adducts weremore » found in rat liver WB-F344 cells treated with a binary mixture, regardless of the exposure time. The observed antagonism between B[a]P and DBC may be due to an inhibition of Cyp1a1 expression because cells exposed to B[a]P:DBC showed a decrease in Cyp1a1 mRNA levels. In human liver HepG2 cells exposed to binary mixtures for 2 h, a reduction in micronuclei frequency was also found. However, after a 24 h treatment, synergism between B[a]P and DBC was determined based on DNA adduct formation. Accordingly, the up-regulation of CYP1A1 expression was detected in HepG2 cells exposed to B[a]P:DBC. Our results show significant differences in the response of human and rat cells to B[a]P:DBC mixtures and stress the need to use multiple experimental systems when evaluating the potential risk of environmental pollutants. Our data also indicate that an increased expression of CYP1A1 results in a synergistic effect of B[a]P and DBC in human cells. As humans are exposed to a plethora of noxious chemicals, our results have important implications for human carcinogenesis. - Highlights: • B[a]P:DBC mixtures were less genotoxic in V79MZh1A1 cells than B[a]P and DBC alone. • An antagonism between B[a]P and DBC was determined in rat liver WB-F344 cells. • The inhibition of CYP1a1 expression by B[a]P:DBC mixture underlies this antagonism. • A synergism between B[a]P and DBC was detected in human liver HepG2 cells. • The up-regulation of CYP1A1 expression was found in B[a]P:DBC-exposed HepG2 cells.« less

Measuring and modeling of binary mixture effects of pharmaceuticals and nickel on cell viability/cytotoxicity in the human hepatoma derived cell line HepG2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudzok, S., E-mail: susanne.rudzok@ufz.d; Schlink, U., E-mail: uwe.schlink@ufz.d; Herbarth, O., E-mail: olf.herbarth@medizin.uni-leipzig.d

2010-05-01

The interaction of drugs and non-therapeutic xenobiotics constitutes a central role in human health risk assessment. Still, available data are rare. Two different models have been established to predict mixture toxicity from single dose data, namely, the concentration addition (CA) and independent action (IA) model. However, chemicals can also act synergistic or antagonistic or in dose level deviation, or in a dose ratio dependent deviation. In the present study we used the MIXTOX model (EU project ENV4-CT97-0507), which incorporates these algorithms, to assess effects of the binary mixtures in the human hepatoma cell line HepG2. These cells possess a liver-likemore » enzyme pattern and a variety of xenobiotic-metabolizing enzymes (phases I and II). We tested binary mixtures of the metal nickel, the anti-inflammatory drug diclofenac, and the antibiotic agent irgasan and compared the experimental data to the mathematical models. Cell viability was determined by three different methods the MTT-, AlamarBlue (registered) and NRU assay. The compounds were tested separately and in combinations. We could show that the metal nickel is the dominant component in the mixture, affecting an antagonism at low-dose levels and a synergism at high-dose levels in combination with diclofenac or irgasan, when using the NRU and the AlamarBlue assay. The dose-response surface of irgasan and diclofenac indicated a concentration addition. The experimental data could be described by the algorithms with a regression of up to 90%, revealing the HepG2 cell line and the MIXTOX model as valuable tool for risk assessment of binary mixtures for cytotoxic endpoints. However the model failed to predict a specific mode of action, the CYP1A1 enzyme activity.« less

Studying of crystal growth and overall crystallization of naproxen from binary mixtures.

PubMed

Kaminska, E; Madejczyk, O; Tarnacka, M; Jurkiewicz, K; Kaminski, K; Paluch, M

2017-04-01

Broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC) were applied to investigate the molecular dynamics and phase transitions in binary mixtures composed of naproxen (NAP) and acetylated saccharides: maltose (acMAL) and sucrose (acSUC). Moreover, the application of BDS method and optical microscopy enabled us to study both crystallization kinetics and crystal growth of naproxen from the solid dispersions with the highest content of modified carbohydrates (1:5wt ratio). It was found that the activation barriers of crystallization estimated from dielectric measurements are completely different for both studied herein mixtures. Much higher E a (=205kJ/mol) was obtained for NAP-acMAL solid dispersion. It is probably due to simultaneous crystallization of both components of the mixture. On the other hand, lower value of E a in the case of NAP-acSUC solid dispersion (81kJ/mol) indicated, that naproxen is the only crystallizing compound. This hypothesis was confirmed by X-ray diffraction studies. We also suggested that specific intermolecular dipole-dipole interactions between active substance and excipient may be an alternative explanation for the difference between activation barrier obtained for NAP-acMAL and NAP-acSUC binary mixtures. Furthermore, optical measurements showed that the activation energy for crystal growth of naproxen increases in binary mixtures. They also revealed that both excipients: acMAL and acSUC move the temperature of the maximum of crystal growth towards lower temperatures. Interestingly, this maximum occurs for nearly the same structural relaxation time, which is a good approximation of viscosity, for all samples. Finally, it was also noticed that although naproxen crystallizes to the same polymorphic form in both systems, there are some differences in morphology of obtained crystals. Thus, the observed behavior may have a significant impact on the bioavailability and dissolution rate of API produced in that way. Copyright © 2016 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sánchez-Salcedo, F. J.; Chametla, Raul O., E-mail: jsanchez@astro.unam.mx

Using time-dependent linear theory, we investigate the morphology of the gravitational wake induced by a binary, whose center of mass moves at velocity V{sub cm} against a uniform background of gas. For simplicity, we assume that the components of the binary are on circular orbits about their common center of mass. The consequences of dynamical friction is twofold. First, gas dynamical friction may drag the center of mass of the binary and cause the binary to migrate. Second, drag forces also induce a braking torque, which causes the orbits of the components of the binary to shrink. We compute themore » drag forces acting on one component of the binary due to the gravitational interaction with its own wake. We show that the dynamical friction force responsible for decelerating the center of mass of the binary is smaller than it is in the point-mass case because of the loss of gravitational focusing. We show that the braking internal torque depends on the Mach numbers of each binary component about their center of mass, and also on the Mach number of the center of mass of the binary. In general, the internal torque decreases with increasing the velocity of the binary relative to the ambient gas cloud. However, this is not always the case. We also mention the relevance of our results to the period distribution of binaries.« less

Four Derivative Spectrophotometric Methods for the Simultaneous Determination of Carmoisine and Ponceau 4R in Drinks and Comparison with High Performance Liquid Chromatography

PubMed Central

Turak, Fatma; Dinç, Mithat; Dülger, Öznur; Özgür, Mahmure Ustun

2014-01-01

Four simple, rapid, and accurate spectrophotometric methods were developed for the simultaneous determination of two food colorants, Carmoisine (E122) and Ponceau 4R (E124), in their binary mixtures and soft drinks. The first method is based on recording the first derivative curves and determining each component using the zero-crossing technique. The second method uses the first derivative of ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of the binary mixture by that of one of the components. The third method, derivative differential procedure, is based on the measurement of difference absorptivities derivatized in first order of solution of drink samples in 0,1 N NaOH relative to that of an equimolar solution in 0,1 N HCl at wavelengths of 366 and 451 nm for Carmoisine and Ponceau 4R, respectively. The last method, based on the compensation method is presented for derivative spectrophotometric determination of E122 and E124 mixtures with overlapping spectra. By using ratios of the derivative maxima, the exact compensation of either component in the mixture can be achieved, followed by its determination. These proposed methods have been successfully applied to the binary mixtures and soft drinks and the results were statistically compared with the reference HPLC method (NMKL 130). PMID:24672549

Control of iron nitride layers growth kinetics in the binary Fe-N system

NASA Astrophysics Data System (ADS)

Torchane, L.; Bilger, P.; Dulcy, J.; Gantois, M.

1996-07-01

This study is within the framework of a research program dedicated to defining the optimal conditions for the nitriding of iron and steels at atmospheric pressure by using various mixtures, NH3-N2-H2 and NH3-Ar. After studying the mechanisms of phase formation and mass transfer at the gas-solid interface, a mathematical model is developed in order to predict the nitrogen transfer rate in the solid, the nitride layer growth rate, and the nitrogen concentration profiles. In order to validate the model and to show its possibilities, it is compared with thermogravimetric experiments, analyses, and metallurgical observations (X-ray diffraction, optical microscopy, and electron microprobe anal-ysis). The results obtained allow us to demonstrate the sound correlation between the experimental results and the theoretical predictions. By applying the model to the iron-nitrogen binary system, when the ɛ/γ/α configuration referred to the Fe-N phase diagram is formed, we have experimentally determined the effective diffusion coefficient of nitrogen in the ɛ phase. The latter is constant for a composition of the ɛ nitride between 8 and 9.5 wt pct nitrogen. All the results obtained show that it is possible, by means of dynamic gas flow regulation, to eliminate the incubation period and to control the thickness, composition, and structure of the compound layer at the beginning of the treatment.

Cosolvent effect on the dynamics of water in aqueous binary mixtures

NASA Astrophysics Data System (ADS)

Zhang, Xia; Zhang, Lu; Jin, Tan; Zhang, Qiang; Zhuang, Wei

2018-04-01

Water rotational dynamics in the mixtures of water and amphiphilic molecules, such as acetone and dimethyl sulfoxide (DMSO), measured by femtosecond infrared, often vary non-monotonically as the amphiphilic molecule's molar fraction changes from 0 to 1. Recent study has attributed the non-ideal water rotation with concentration in DMSO-water mixtures to different microscopic hydrophilic-hydrophobic segregation structure in water-rich and water-poor mixtures. Interestingly, the acetone molecule has very similar molecular structure to DMSO, but the extremum of the water rotational time in the DMSO-water mixtures significantly shifts to lower concentration and the rotation of water is much faster than those in acetone-water mixtures. The simulation results here shows that the non-ideal rotational dynamics of water in both mixtures are due to the frame rotation during the interval of hydrogen bond (HB) switchings. A turnover of the frame rotation with concentration takes place as the structure transition of mixture from the hydrogen bond percolation structure to the hydrophobic percolation structure. The weak acetone-water hydrogen bond strengthens the hydrophobic aggregation and accelerates the relaxation of the hydrogen bond, so that the structure transition takes places at lower concentration and the rotation of water is faster in acetone-water mixture than in DMSO-water mixture. A generally microscopic picture on the mixing effect on the water dynamics in binary aqueous mixtures is presented here.

Calculation and characteristic analysis on synergistic effect of CF3I gas mixtures

NASA Astrophysics Data System (ADS)

Su, ZHAO; Yunkun, DENG; Yuhao, GAO; Dengming, XIAO

2018-06-01

CF3I is a potential SF6 alternative gas. In order to study the insulation properties and synergistic effects of CF3I/N2 and CF3I/CO2 gas mixtures, two-term approximate Boltzmann equations were used to obtain the ionization coefficient α, attachment coefficient η and the critical equivalent electrical field strength (E/N)cr. The results show that the (E/N)cr of CF3I gas at 300 K is 1.2 times that of SF6 gas, and CF3I/N2 and CF3I/CO2 gas mixtures both have synergistic effect occurred. The synergistic effect coefficient of CF3I/CO2 gas mixture was higher than that of CF3I/N2 gas mixture. But the (E/N)cr of CF3I/N2 is higher than that of CF3I/CO2 under the same conditions. When the content of CF3I exceeds 20%, the (E/N)cr of CF3I/N2 and CF3I/CO2 gas mixture increase linearly with the increasing of CF3I gas content. The breakdown voltage of CF3I/N2 gas mixture is also higher than that of CF3I/CO2 gas mixture in slightly non-uniform electrical field under power frequency voltage, but the synergistic effect coefficients of the two gas mixtures are basically the same.

Optimizing the separation performance of a gas centrifuge

NASA Astrophysics Data System (ADS)

Wood, H. G.

1997-11-01

Gas centrifuges were originally developed for the enrichment of U^235 from naturally occurring uranium for the purpose of providing fuel for nuclear power reactors and material for nuclear weapons. This required the separation of a binary mixture composed of U^235 and U^238. Since the end of the cold war, a surplus of enriched uranium exists on the world market, but many centrifuge plants exist in numerous countries. These circumstances together with the growing demand for stable isotopes for chemical and physical research and in medical science has led to the exploration of alternate applications of gas centrifuge technology. In order to acieve these multi-component separations, existing centrifuges must be modified or new centrifuges must be designed. In either case, it is important to have models of the internal flow fields to predict the separation performance and algorithms to seek the optimal operating conditions of the centrifuges. Here, we use the Onsager pancake model of the internal flow field, and we present an optimization strategy which exploits a similarity parameter in the pancake model. Numerical examples will be presented.

Study of excess dielectric properties and Kirkwood correlation parameter of binary mixtures of benzaldehyde and methanol at different temperatures

NASA Astrophysics Data System (ADS)

Shah, N. S.; Vankar, H. P.; Rana, V. A.

2018-05-01

Static permittivity (ɛ0) and permittivity at optical frequency (ɛ∞) of the Benzaldehyde (BZ), Methanol (MeOH) and their binary mixtures were measured in the temperature range from 293.15 K to 323.15 K (in the interval of 10 K). From the ɛ0 and ɛ∞ other parameters such as effective Kirkwood correlation factor (geff), corrective Kirkwood correction factor (gf), Bruggman factor (fB), excess permittivity (ɛ0E ) and permittivity at optical frequency (ɛ∞E ) were evaluated.

Proteomic analysis of a model fish species exposed to individual pesticides and a binary mixture--Presentation

EPA Science Inventory

Pesticides are nearly ubiquitous in surface waters of the United States, where they often are found as mixtures. The molecular mechanisms underlying the toxic effects of sub-lethal exposure to pesticides as both individual and mixtures are unclear. The current work aims to ident...

Modeling the binary circumstellar medium of Type IIb/L/n supernova progenitors

NASA Astrophysics Data System (ADS)

Kolb, Christopher; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

2018-01-01

Circumstellar interaction in close binary systems can produce a highly asymmetric environment, particularly for systems with a mass outflow velocity comparable to the binary orbital speed. This asymmetric circumstellar medium (CSM) becomes visible after a supernova explosion, when SN radiation illuminates the gas and when SN ejecta collide with the CSM. We aim to better understand the development of this asymmetric CSM, particularly for binary systems containing a red supergiant progenitor, and to study its impact on supernova morphology. To achieve this, we model the asymmetric wind and subsequent supernova explosion in full 3D hydrodynamics using the shock-capturing hydro code VH-1 on a spherical yin-yang grid. Wind interaction is computed in a frame co-rotating with the binary system, and gas is accelerated using a radiation pressure-driven wind model where optical depth of the radiative force is dependent on azimuthally-averaged gas density. We present characterization of our asymmetric wind density distribution model by fitting a polar-to-equatorial density contrast function to free parameters such as binary separation distance, primary mass loss rate, and binary mass ratio.

An odorant congruent with a colour cue is selectively perceived in an odour mixture.

PubMed

Arao, Mari; Suzuki, Maya; Katayama, Jun'ich; Akihiro, Yagi

2012-01-01

Odour identification can be influenced by colour cues. This study examined the mechanism underlying this colour context effect. We hypothesised that a specific odour component congruent with a colour would be selectively perceived in preference to another odour component in a binary odour mixture. We used a ratio estimation method under two colour conditions, a binary odour mixture (experiment 1) and single chemicals presented individually (experiment 2). Each colour was congruent with one of the odour components. Participants judged the perceived mixture ratio in each odour container on which a colour patch was pasted. An influence of colour was not observed when the odour stimulus did not contain the odour component congruent with the colour (experiment 2); however, the odour component congruent with the colour was perceived as more dominant when the odour stimulus did contain the colour-congruent odorant (experiment 1). This pattern indicates that a colour-congruent odour component is selectively perceived in an odour mixture. This finding suggests that colours can enhance the perceptual representation of the colour-associated component in an odour mixture.

Electron-ion recombination in low temperature hydrogen/deuterium plasma

NASA Astrophysics Data System (ADS)

Glosík, Juraj; Dohnal, Petr; Kálosi, Ábel; Augustovičová, Lucie D.; Shapko, Dmytro; Roučka, Štěpán; Plašil, Radek

2018-01-01

The stationary afterglow with cavity ring down spectrometer (SA-CRDS) was used to study the recombination of H3+, H2D+, HD2+ and D3+ ions with electrons in low temperature (77-300 K) plasmas in He/Ar/H2/D2 gas mixtures. By measuring effective recombination rate coefficients (αeff) in plasma with mixtures of ions and their dependences on temperature and partial densities of He, H2 and D2, αeff (T, [He],[H2],[D2]), we determined binary (αbinH3, αbinH2D, αbinHD2, αbinD3) and ternary (KH3, KH2D, KHD2, KD3) recombination rate coefficients for H3+, H2D+, HD2+ and D3+ ions. For all four ions we observed very efficient He assisted ternary recombination which is comparable with binary recombination already at [He] =1 × 1017 cm-3. The removal of excited particles in afterglow plasma was monitored to obtain the plasma thermalisation rate at given experimental conditions. The inferred deexcitation rates for reaction of helium metastable atoms with D2 are kD2 (300 K)=(2.1 ± 0.3) × 10-10 cm3 s-1 and kD2 (140 K)=(1.3 ± 0.3) × 10-10 cm3 s-1. Contribution to the topical issue "Plasma Sources and Plasma Processes (PSPP)", edited by Luis Lemos Alves, Thierry Belmonte and Tiberiu Minea.

Observation of vapor bubble of non-azeotropic binary mixture in microgravity with a two-wavelength interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abe, Yoshiyuki; Iwasaki, Akira

1999-07-01

Although non-azeotropic mixtures are considered to be promising working fluids in advanced energy conversion systems, the primary technical problems in the heat transfer degradation in phase change processes cause economical handicap to wide-spread applications. The boiling behavior of mixtures still remains a number of basic questions being not answered yet, and the present authors believe that the most essential information for the boiling process in non-azeotropic mixtures is how temperature and concentration profiles are developed around the bubbles. The present study attempts at understanding fundamental heat and mass transfer mechanisms in nucleate pool boiling of non-azeotropic binary mixtures, and withmore » the knowledge to develop a passive boiling heat transfer enhancement eventually. To this end, the authors have employed microgravity environment for rather detailed observation around vapor bubbles in the course of boiling inception and bubble growth. A two-wavelength Mach-Zehnder interferometer has been developed, which withstands mechanical shock caused by gravity change from very low gravity of the order of 10{sup {minus}5} g to relatively high gravity of approximately 8 g exposed during deceleration period. A series of experiments on single vapor bubbles for CFC113 single component and CFC12/CFC112 non-azeotropic binary mixture have been conducted under a high quality microgravity conditions available in 10-second free-fall facility of Japan Microgravity Center (JAMIC). The results for single component liquid showed a strong influence due to Marangoni effect caused by the temperature profile around the bubble. The results for non-azeotropic binary mixture showed, however, considerably different behavior from single component liquid. Both temperature and concentration profiles around a single vapor bubble were evaluated from the interferograms. The temperature and concentration layers established around the bubbles were nearly one order of magnitude larger than those predicted by thermal diffusion and mass diffusion. The temperature and concentration profiles evaluated from the present experiments suggest the role of Marangoni effects due to both concentration profile and temperature profile around the bubble interface.« less

Finite-Size Effects of Binary Mutual Diffusion Coefficients from Molecular Dynamics

PubMed Central

2018-01-01

Molecular dynamics simulations were performed for the prediction of the finite-size effects of Maxwell-Stefan diffusion coefficients of molecular mixtures and a wide variety of binary Lennard–Jones systems. A strong dependency of computed diffusivities on the system size was observed. Computed diffusivities were found to increase with the number of molecules. We propose a correction for the extrapolation of Maxwell–Stefan diffusion coefficients to the thermodynamic limit, based on the study by Yeh and Hummer (J. Phys. Chem. B, 2004, 108, 15873−15879). The proposed correction is a function of the viscosity of the system, the size of the simulation box, and the thermodynamic factor, which is a measure for the nonideality of the mixture. Verification is carried out for more than 200 distinct binary Lennard–Jones systems, as well as 9 binary systems of methanol, water, ethanol, acetone, methylamine, and carbon tetrachloride. Significant deviations between finite-size Maxwell–Stefan diffusivities and the corresponding diffusivities at the thermodynamic limit were found for mixtures close to demixing. In these cases, the finite-size correction can be even larger than the simulated (finite-size) Maxwell–Stefan diffusivity. Our results show that considering these finite-size effects is crucial and that the suggested correction allows for reliable computations. PMID:29664633

Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

2016-03-01

Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.

Bondi-Hoyle-Lyttleton Accretion onto Binaries

NASA Astrophysics Data System (ADS)

Antoni, Andrea; MacLeod, Morgan; Ramírez-Ruiz, Enrico

2018-01-01

Binary stars are not rare. While only close binary stars will eventually interact with one another, even the widest binary systems interact with their gaseous surroundings. The rates of accretion and the gaseous drag forces arising in these interactions are the key to understanding how these systems evolve. This poster examines accretion flows around a binary system moving supersonically through a background gas. We perform three-dimensional hydrodynamic simulations of Bondi-Hoyle-Lyttleton accretion using the adaptive mesh refinement code FLASH. We simulate a range of values of semi-major axis of the orbit relative to the gravitational focusing impact parameter of the pair. On large scales, gas is gravitationally focused by the center-of-mass of the binary, leading to dynamical friction drag and to the accretion of mass and momentum. On smaller scales, the orbital motion imprints itself on the gas. Notably, the magnitude and direction of the forces acting on the binary inherit this orbital dependence. The long-term evolution of the binary is determined by the timescales for accretion, slow down of the center-of-mass, and decay of the orbit. We use our simulations to measure these timescales and to establish a hierarchy between them. In general, our simulations indicate that binaries moving through gaseous media will slow down before the orbit decays.

Abnormal characteristics of binary molecular clusters in DMSO–ethanol mixtures under external electric fields

NASA Astrophysics Data System (ADS)

Wu, Zhiyan; Huang, Kama

2018-05-01

For the nonlinearly phenomena on the dielectric properties of dimethyl sulfoxide (DMSO)-ethanol mixtures under a low intensity microwave field, we propose a conjecture that there exist some abnormal molecular clusters. To interpret the mechanism of abnormal phenomena and confirm our conjecture about the existence of abnormal molecular clusters, an in-depth investigation about the structure evolutions of (DMSO)m(C2H5OH)n (m = 0-4; n = 0-4; m + n ≤ 4) molecular clusters induced by external electric fields has been given by using density functional theory. The results show that there exist some binary molecular clusters with large cluster radii in mixtures, and some of them are unstable under exposure of electric fields. It implies that the existence of certain abnormal molecular clusters in DMSO-ethanol mixtures results in their abnormality of dielectric properties.

A physicochemical investigation of ionic liquid mixtures† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc02931c Click here for additional data file.

PubMed Central

Clough, Matthew T.; Crick, Colin R.; Gräsvik, John; Niedermeyer, Heiko; Whitaker, Oliver P.

2015-01-01

Ionic liquids have earned the reputation of being ‘designer solvents’ due to the wide range of accessible properties and the degree of fine-tuning afforded by varying the constituent ions. Mixtures of ionic liquids offer the opportunity for further fine-tuning of properties. A broad selection of common ionic liquid cations and anions are employed to create a sample of binary and reciprocal binary ionic liquid mixtures, which are analysed and described in this paper. Physical properties such as the conductivity, viscosity, density and phase behaviour (glass transition temperatures) are examined. In addition, thermal stabilities of the mixtures are evaluated. The physical properties examined for these formulations are found to generally adhere remarkably closely to ideal mixing laws, with a few consistent exceptions, allowing for the facile prediction and control of properties of ionic liquid mixtures. PMID:29560198

Physical properties of new binary antiferroelectric liquid crystal mixtures

NASA Astrophysics Data System (ADS)

Fitas, Jakub; Jaworska-Gołąb, Teresa; Deptuch, Aleksandra; Tykarska, Marzena; Kurp, Katarzyna; Żurowska, Magdalena; Marzec, Monika

2018-02-01

Three newly prepared binary mixtures exhibiting chiral tilted smectic phases have been studied using differential scanning calorimetry, dielectric spectroscopy and electro-optic method, as well as X-ray diffraction. Broad temperature range of ferroelectric and antiferroelectric phases was detected in these mixtures and temperature dependence of spontaneous polarization, tilt angle and switching time were measured for all of them. It's occurred that all of the studied mixtures are orthoconic antiferroelectric liquid crystals. Based on the X-ray diffraction results, the temperature dependence of layer thickness in the paraelectric, ferroelectric and antiferroelectric phases was found. By using dielectric spectroscopy, Goldstone mode was identified in the ferroelectric phase, while antiphase fluctuations of azimuthal angle have been found in the antiferroelectric phase. Based on the results of the complementary methods, the transition temperatures were found as well as the order of the para-ferroelectric phase transition was determined as non-continuous one with critical parameter β equal to ca. 0.25.

Using chromatography – desorption method of manufacturing gas mixtures for analytical instruments calibration

NASA Astrophysics Data System (ADS)

Platonov, I. A.; Kolesnichenko, I. N.; Lange, P. K.

2018-05-01

In this paper, the chromatography desorption method of obtaining gas mixtures of known compositions stable for a time sufficient to calibrate analytical instruments is considered. The comparative analysis results of the preparation accuracy of gas mixtures with volatile organic compounds using diffusion, polyabarbotage and chromatography desorption methods are presented. It is shown that the application of chromatography desorption devices allows one to obtain gas mixtures that are stable for 10...60 hours in a dynamic condition. These gas mixtures contain volatile aliphatic and aromatic hydrocarbons with a concentration error of no more than 7%. It is shown that it is expedient to use such gas mixtures for analytical instruments calibration (chromatographs, spectrophotometers, etc.)

Buffer gas cooling and mixture analysis

DOEpatents

Patterson, David S.; Doyle, John M.

2018-03-06

An apparatus for spectroscopy of a gas mixture is described. Such an apparatus includes a gas mixing system configured to mix a hot analyte gas that includes at least one analyte species in a gas phase into a cold buffer gas, thereby forming a supersaturated mixture to be provided for spectroscopic analysis.

Testing the accuracy of correlations for multicomponent mass transport of adsorbed gases in metal-organic frameworks: diffusion of H2/CH4 mixtures in CuBTC.

PubMed

Keskin, Seda; Liu, Jinchen; Johnson, J Karl; Sholl, David S

2008-08-05

Mass transport of chemical mixtures in nanoporous materials is important in applications such as membrane separations, but measuring diffusion of mixtures experimentally is challenging. Methods that can predict multicomponent diffusion coefficients from single-component data can be extremely useful if these methods are known to be accurate. We present the first test of a method of this kind for molecules adsorbed in a metal-organic framework (MOF). Specifically, we examine the method proposed by Skoulidas, Sholl, and Krishna (SSK) ( Langmuir, 2003, 19, 7977) by comparing predictions made with this method to molecular simulations of mixture transport of H 2/CH 4 mixtures in CuBTC. These calculations provide the first direct information on mixture transport of any species in a MOF. The predictions of the SSK approach are in good agreement with our direct simulations of binary diffusion, suggesting that this approach may be a powerful one for examining multicomponent diffusion in MOFs. We also use our molecular simulation data to test the ideal adsorbed solution theory method for predicting binary adsorption isotherms and a method for predicting mixture self-diffusion coefficients.

Estimation of interfacial area in a packed cross-flow cascade with distillation of ethanol-water, methanol-water, and hexane-heptane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velaga, A.

1986-01-01

Packed cross-flow internals consisting of four and ten stages including the samplers for liquid and vapor were fabricated to fit into the existing distillation column. Experiments were conducted using methanol-water, ethanol-water and hexane-heptane binary mixtures. The experimental data were collected for compositions of inlet and exist streams of cross-flow stages. The overall gas phase height transfer units (H/sub og/) were estimated using the experimental data. H/sub og/ values were compared to those of counter current conditions. The individual mass transfer coefficients in the liquid and vapor phases were estimated using the collected experimental data for degree of separation, flow ratesmore » and physical properties of the binary system used. The physical properties were estimated at an average temperature of the specific cross-flow stage. The mass transfer coefficients were evaluated using three different correlations proposed by Shulman. Onda and Hayashi respectively. The interfacial areas were estimated using the evaluated mass transfer coefficients and the experimental data at each stage of the column for different runs and compared.« less

Adsorption of N-hexane, methanol and water vapor and binary mixtures of N-hexane/water vapor on super activated carbon nanoparticles

NASA Astrophysics Data System (ADS)

Prado, Jesus Antonio

Recent times have seen a large rise in the utilization of engineered nanomaterials (ENMs) within a wide variety of industries due to their unique properties. Consequently, the fabrication, application and disposal of ENMs will inevitably lead to their release to the environment. Once ENMs are in the environment, they may undergo atmospheric transformations, such the sorption of hazardous air pollutants (HAPs) or water vapor. These transformed ENMs may then affect the general public through inhalation -- or other pathways of exposure -- and those employed by the ever-growing nanotechnology sector are of particular vulnerability. As a result, it is important to evaluate the adsorption characteristics of a common carbon-based ENM under the presence of HAPs or water vapor which may adsorb onto them. This study investigated the unary and binary gas-phase adsorption of n-hexane, methanol and water vapor on super activated carbon nanoparticles (SACNPs) with a bench-scale adsorption system. Removal efficiencies, breakthrough tests, throughput ratios, adsorption capacities and kinetics modeling were completed to assess the adsorption behavior of the SACNPs.

Rapid formation of supermassive black hole binaries in galaxy mergers with gas.

PubMed

Mayer, L; Kazantzidis, S; Madau, P; Colpi, M; Quinn, T; Wadsley, J

2007-06-29

Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that after the merger of two massive galaxies, a SMBH binary will form, shrink because of stellar or gas dynamical processes, and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas because of the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years after the collision between two spiral galaxies. A massive, turbulent, nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than 1 million years as a result of the gravitational drag from the gas rather than from the stars.

Marangoni Effects in the Boiling of Binary Fluid Mixtures

NASA Technical Reports Server (NTRS)

Ahmed, Sayeed; Carey, Van P.; Motil, Brian

1996-01-01

Results of very recent experimental studies indicate that during nucleate boiling in some binary mixture, Marangoni effects augment the gravity driven flow of liquid towards the heated surface. With gravity present, it is impossible to separate the two effects. The reduced gravity environment gives an unique opportunity to explore th role of Marangoni effects on the boiling mechanisms free of gravitational body forces that obscure the role of such effects. However, recent experimental results suggest that under reduced gravity conditions, Marangoni effects is the dominant mechanism of vapor-liquid exchange at the surface for some binary mixture. To further explore such effects, experiments have been conducted with water/2-propanol mixtures at three different concentrations under normal gravity with different orientations of the heater surface and under reduce gravity aboard the DC-9 aircraft at NASA Lewis Research Center. The system pressure was sub atmospheric (approx. 8 kP at 1g(n)) and the bulk liquid temperature varied from low subcooling to near saturation. The molar concentrations of 2-propanol tested were 0.015, 0.025, and 0.1. Boiling curves were obtained both for high gravity (approx. 2g(n)) and reduce gravity (approx. 0.01g(n)). For each concentration of 2-propanol, the critical heat flux has been determined in the flight experiments only for reduced gravity conditions. Comparison of boiling curves and CHF obtained under l-g(n) an reduced gravity indicates that boiling mechanism in this mixtures is nearly independent of gravity. The results also indicate that the Marangoni mechanism is strong enough in these mixtures to sustain the boiling under reduced gravity conditions.

Effects of binary taste stimuli on the neural activity of the hamster chorda tympani

PubMed Central

1980-01-01

Binary mixtures of taste stimuli were applied to the tongue of the hamster and the reaction of the whole corda tympani was recorded. Some of the chemicals that were paired in mixtures (HCl, NH4Cl, NaCl, CaCl2, sucrose, and D-phenylalanine) have similar tastes to human and/or hamster, and/or common stimulatory effects on individual fibers of the hamster chorda tympani; other pairs of these chemicals have dissimilar tastes and/or distinct neural stimulatory effects. The molarity of each chemical with approximately the same effect on the activity of the nerve as 0.01 M NaCl was selected, and an established relation between stimulus concentration and response allowed estimation of the effect of a "mixture" of two concentrations of one chemical. Each mixture elicited a response that was smaller than the sum of the responses to its components. However, responses to some mixtures approached this sum, and responses to other mixtures closely approached the response to a "mixture" of two concentrations of one chemical. Responses of the former variety were generated by mixtures of an electrolyte and a nonelectrolyte and the latter by mixtures of two electrolytes or two nonelectrolytes. But, beyond the distinction between electrolytes and nonelectrolytes, the whole-nerve response to a mixture could not be predicted from the known neural or psychophysical effects of its components. PMID:7411114

Enhanced toxicity of binary mixtures of Bacillus thuringiensis subsp. israelensis and three essential oil major constituents to wild Anopheles sinensis (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae).

PubMed

Chang, Kyu-Sik; Shin, E-Hyun; Yoo, Dae-Hyun; Ahn, Young-Joon

2014-07-01

An assessment was made of the toxicity of 12 insecticides and three essential oils as well as Bacillus thuringiensis subsp. israelensis (Bti) alone or in combination with the oil major constituents (E)-anethole (AN), (E) -cinnamaldehyde (CA), and eugenol (EU; 1:1 ratio) to third instars of bamboo forest-collected Aedes albopictus (Skuse) and rice paddy field-collected Anopheles sinensis Wiedemann. An. sinensis larvae were resistant to various groups of the tested insecticides. Based on 24-h LC50 values, binary mixtures of Bti and CA, AN, or EU were significantly more toxic against Ae. albopictus larvae (0.0084, 0.0134, and 0.0237 mg/liter) and An. sinensis larvae (0.0159, 0.0388, and 0.0541 mg/liter) than either Bti (1.7884 and 2.1681 mg/liter) or CA (11.46 and 18.56 mg/liter), AN (16.66 and 25.11 mg/liter), or EU (24.60 and 31.09 mg/liter) alone. As judged by cotoxicity coefficient (CC) and synergistic factor (SF), the three binary mixtures operated in a synergy pattern (CC, 140.7-368.3 and SF, 0.0007-0.0010 for Ae. albopictus; CC, 75.1-245.3 and SF, 0.0008-0.0017 for An. sinensis). Global efforts to reduce the level of highly toxic synthetic insecticides in the aquatic environment justify further studies on the binary mixtures of Bti and essential oil constituents described, in particular CA, as potential larvicides for the control of malaria vector mosquito populations.

Novel two wavelength spectrophotometric methods for simultaneous determination of binary mixtures with severely overlapping spectra

NASA Astrophysics Data System (ADS)

Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

2015-02-01

This work presents the application of different spectrophotometric techniques based on two wavelengths for the determination of severely overlapped spectral components in a binary mixture without prior separation. Four novel spectrophotometric methods were developed namely: induced dual wavelength method (IDW), dual wavelength resolution technique (DWRT), advanced amplitude modulation method (AAM) and induced amplitude modulation method (IAM). The results of the novel methods were compared to that of three well-established methods which were: dual wavelength method (DW), Vierordt's method (VD) and bivariate method (BV). The developed methods were applied for the analysis of the binary mixture of hydrocortisone acetate (HCA) and fusidic acid (FSA) formulated as topical cream accompanied by the determination of methyl paraben and propyl paraben present as preservatives. The specificity of the novel methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

Molecular investigation on the binding of Cd(II) by the binary mixtures of montmorillonite with two bacterial species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Huihui; Qu, ChenChen; Liu, Jing

Bacteria and phyllosilicate commonly coexist in the natural environment, producing various bacteria–clay complexes that are capable of immobilizing heavy metals, such as cadmium, via adsorption. However, the molecular binding mechanisms of heavy metals on these complex aggregates still remain poorly understood. This study investigated Cd adsorption on Gram-positive B. subtilis, Gram-negative P. putida and their binary mixtures with montmorillonite (Mont) using the Cd K-edge x-ray absorption spectroscopy (XAS) and isothermal titration calorimetry (ITC). We observed a lower adsorptive capacity for P. putida than B. subtilis, whereas P. putida–Mont and B. subtilis–Mont mixtures showed nearly identical Cd adsorption behaviors. EXAFS fitsmore » and ITC measurements demonstrated more phosphoryl binding of Cd in P. putida. The decreased coordination of C atoms around Cd and the reduced adsorption enthalpies and entropies for the binary mixtures compared to that for individual bacteria suggested that the bidentate Cd-carboxyl complexes in pure bacteria systems were probably transformed into monodentate complexes that acted as ionic bridging structure between bacteria and motmorillonite. This study clarified the binding mechanism of Cd at the bacteria–phyllosilicate interfaces from a molecular and thermodynamic view, which has an environmental significance for predicting the chemical behavior of trace elements in complex mineral–organic systems.« less

Preferential solvation of Brooker's merocyanine in binary solvent mixtures composed of formamides and hydroxylic solvents.

PubMed

Bevilaqua, Tharly; da Silva, Domingas C; Machado, Vanderlei G

2004-03-01

The ET polarity values of 4-[(1-methyl-4(1H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one (Brooker's merocyanine) were collected in mixed-solvent systems comprising a formamide [N,N-dimethylformamide (DMF), N-methylformamide (NMF) or formamide (FA)] and a hydroxylic (water, methanol, ethanol, propan-2-ol or butan-1-ol) solvent. Binary mixtures involving DMF and the other formamides (NMF and FA) as well as NMF and FA were also studied. These data were employed in the investigation of the preferential solvation (PS) of the probe. Each solvent system was analyzed in terms of both solute-solvent and solvent-solvent interactions. These latter interactions were responsible for the synergism observed in many binary mixtures. This synergistic behaviour was observed for DMF-propan-2-ol, DMF-butan-1-ol, FA-methanol, FA-ethanol and for the mixtures of the alcohols with NMF. All data were successfully fitted to a model based on solvent-exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. The results suggest that both hydrogen bonding and solvophobic interactions contribute to the formation of the solvent complexes responsible for the observed synergistic effects in the PS of the dye.

Investigation of Deviations from Ideality in the Two Liquid Phase Region of Systems of Medium Molecular Weight Hydrocarbon Mixtures and Water.

DTIC Science & Technology

1986-02-01

determined by refractometry using a Bausch and Lomb Refractometer (Abbe 3-L). Refractive index calibrations for the binary mixtures examined are given in...mixture sample was taken and analyzed by refractometry . b. Results The results of the vapor pressure experiments and the Redlich- Kister coefficients

Diffuse interface method for a compressible binary fluid.

PubMed

Liu, Jiewei; Amberg, Gustav; Do-Quang, Minh

2016-01-01

Multicomponent, multiphase, compressible flows are very important in real life, as well as in scientific research, while their modeling is in an early stage. In this paper, we propose a diffuse interface model for compressible binary mixtures, based on the balance of mass, momentum, energy, and the second law of thermodynamics. We show both analytically and numerically that this model is able to describe the phase equilibrium for a real binary mixture (CO_{2} + ethanol is considered in this paper) very well by adjusting the parameter which measures the attraction force between molecules of the two components in the model. We also show that the calculated surface tension of the CO_{2} + ethanol mixture at different concentrations match measurements in the literature when the mixing capillary coefficient is taken to be the geometric mean of the capillary coefficient of each component. Three different cases of two droplets in a shear flow, with the same or different concentration, are simulated, showing that the higher concentration of CO_{2} the smaller the surface tension and the easier the drop deforms.

Dynamics of glycerine and water transport across human skin from binary mixtures.

PubMed

Ventura, S A; Kasting, G B

2017-04-01

Skin transport properties of glycerine and water from binary mixtures contacting human skin were determined to better understand the mechanism of skin moisturization by aqueous glycerine formulations. Steady-state permeation for 3 H 2 O and 14 C-glycerine across split-thickness human skin in vitro and desorption dynamics of the same permeants in isolated human stratum corneum (HSC) were experimentally determined under near equilibrium conditions. These data were compared to a priori values developed in the context of a thermodynamic model for binary mixtures of glycerine and water and a previously determined water sorption isotherm for HSC. This allowed the estimation of diffusion and partition coefficients for each permeant in the HSC, as well as HSC thickness, as a function of composition of the contacting solution. These data may be used to estimate water retention and associated HSC swelling related to the absorption and slow release of glycerine from the skin. It took 6+ days for glycerine to completely desorb from HSC immersed in glycerine/water binary solutions. Desorption of both 3 H 2 O and 14 C-glycerine from HSC was slower in pure water than from binary mixtures, a result that is largely explained by the greater swelling of HSC in water. Parametric relationships were developed for water and glycerine intradiffusivities in HSC as functions of HSC water content, and a mutual diffusion coefficient was estimated by analogy with glycerine/water binary solutions. The intradiffusivity of 14 C-glycerine in HSC as inferred from sorption/desorption experiments was shown to be approximately 10-fold less than that inferred from permeation experiments, whereas the corresponding values for 3 H 2 O were comparable. These studies confirm that glycerine enters HSC in substantial quantities and has a long residence time therein. The coupling between bulk water and glycerine transport projected from binary solution data suggests the net effect of glycerine is to slow water loss from the skin. The data support the concept of glycerine as a humectant with an excellent balance of skin penetration and retention characteristics; however, they do not rule out the possibility of an additional biological effect on skin barrier homoeostasis. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Method of dehydrating natural gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, R. E.

1985-01-01

A method for dehydration of natural gas is provided wherein well head gas is supplied to a three-phase inlet separator, the vapor mixture of natural gas and water removed from that inlet separator means is supplied to a turboexpander, and the resulting refrigerated mixture of natural gas and condensed water vapor is supplied to a multi-phase outlet separator. The turboexpander may have integral means for subsequent compression of the refrigerated mixture and may be coupled through reduction gears to a means for generating electricity. A portion of the refrigerated mixture may be connected to a heat exchanger for cooling themore » well head natural gas prior to entry into the inlet separator. The flow of refrigerated mixture to this heat exchanger may be controlled by a temperature sensitive valve downstream of the heat exchanger. Methanol may be injected into the vapor mixture prior to entry into the turboexpander. The flow of methanol into the vapor mixture may be controlled by a valve sensitive to the flow rate of the vapor mixture and the water vapor content of the refrigerated mixture. Natural gas vapor from the outlet separator may be recirculated through the turboexpander if the output water vapor content of the natural gas vapor stream is too high.« less

New approach in direct-simulation of gas mixtures

NASA Technical Reports Server (NTRS)

Chung, Chan-Hong; De Witt, Kenneth J.; Jeng, Duen-Ren

1991-01-01

Results are reported for an investigation of a new direct-simulation Monte Carlo method by which energy transfer and chemical reactions are calculated. The new method, which reduces to the variable cross-section hard sphere model as a special case, allows different viscosity-temperature exponents for each species in a gas mixture when combined with a modified Larsen-Borgnakke phenomenological model. This removes the most serious limitation of the usefulness of the model for engineering simulations. The necessary kinetic theory for the application of the new method to mixtures of monatomic or polyatomic gases is presented, including gas mixtures involving chemical reactions. Calculations are made for the relaxation of a diatomic gas mixture, a plane shock wave in a gas mixture, and a chemically reacting gas flow along the stagnation streamline in front of a hypersonic vehicle. Calculated results show that the introduction of different molecular interactions for each species in a gas mixture produces significant differences in comparison with a common molecular interaction for all species in the mixture. This effect should not be neglected for accurate DSMC simulations in an engineering context.

Surface segregation in binary mixtures of imidazolium-based ionic liquids

NASA Astrophysics Data System (ADS)

Souda, Ryutaro

2010-09-01

Surface composition of binary mixtures of room-temperature ionic liquids has been investigated using time-of-flight secondary ion mass spectrometry at room temperature over a wide composition range. The imidazolium cations with longer aliphatic groups tend to segregate to the surface, and a bis(trifluoromethanesulfonyl)imide anion (Tf 2N -) is enriched at the surface relative to hexafluorophosphate (PF 6-). The surface of an equimolar mixture of Li[Tf 2N] and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF 6]) has a nominal composition of [bmim][Tf 2N] because of surface segregation and ligand exchange. The surface segregation of cations and anions is likely to result from alignment of specific ligand-exchanged molecules at the topmost surface layer to exclude more hydrophobic part of the molecules.

Phase-transition oscillations induced by a strongly focused laser beam

NASA Astrophysics Data System (ADS)

Devailly, Clémence; Crauste-Thibierge, Caroline; Petrosyan, Artyom; Ciliberto, Sergio

2015-11-01

We report the observation of a surprising phenomenon consisting in a oscillating phase transition which appears in a binary mixture when this is enlightened by a strongly focused infrared laser beam. The mixture is poly-methyl-meth-acrylate (PMMA)-3-octanone, which has an upper critical solution temperature at Tc=306.6 K and volume fraction ϕc=12.8 % [Crauste et al., arXiv:1310.6720, 2013]. We describe the dynamical properties of the oscillations, which are produced by a competition between various effects: the local accumulation of PMMA produced by the laser beam, thermophoresis, and nonlinear diffusion. We show that the main properties of this kind of oscillations can be reproduced in the Landau theory for a binary mixture in which a local driving mechanism, simulating the laser beam, is introduced.

Study on Solution Properties of Binary Mixtures of Some Industrially Important Solvents with Cyclohexylamine and Cyclohexanone at 298.15 K

NASA Astrophysics Data System (ADS)

Roy, Mahendra Nath; Das, Rajesh Kumar; Chanda, Riju

2010-03-01

Densities and viscosities were measured for the binary mixtures of cyclohexylamine and cyclohexanone with butyl acetate, butanone, butylamine, tert-butylamine, and 2-butoxyethanol at 298.15 K over the entire composition range. From density data, the values of the excess molar volume ( V E) have been calculated. The experimental viscosity data were correlated by means of the equation of Grunberg-Nissan. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models. The results are discussed in terms of molecular interactions and structural effects. The excess molar volume is found to be either negative or positive depending on the molecular interactions and the nature of the liquid mixtures and is discussed in terms of molecular interactions and structural changes.

Electrical properties of binary mixtures of amino silicone oil and methyl iso butyl ketone

NASA Astrophysics Data System (ADS)

Shah, K. N.; Rana, V. A.; Vankar, H. P.

2018-05-01

The real and imaginary parts of the dielectric function of the binary mixtures of the methyl iso butyl ketone and amino silicone oil in the frequency range 100 Hz to 2 MHz were measured using precision LCR meter at 305.15 K. The electrical properties such as electrical modulus M*(ω), electrical conductivity σ*(ω) and complex impedance Z*(ω) were calculated using the dielectric function ɛ*(ω). The ionic polarization relaxation time (Τσ) and D.C. conductivity (σdc) were also calculated using electrical properties. The ionic behavior of methyl iso butyl ketone and non-ionic behavior of amino silicone oil are also explained. The electrical parameters are used to gain information about the effect of concentration variation of components of the mixtures on the electrical properties.

The structures of the crystalline phase and columnar mesophase of rhodium (II) heptanoate and of its binary mixture with copper (II) heptanoate probed by EXAFS

NASA Astrophysics Data System (ADS)

Inb-Elhaj, M.; Guillon, D.; Skoulios, A.; Maldivi, P.; Giroud-Godquin, A. M.; Marchon, J.-C.

1992-12-01

EXAFS was used to investigate the local structure of the polar spines of rhodium (II) soaps in the columnar liquid crystalline state. It was also used to ascertain the degree of blending of the cores in binary mixtures of rhodium (II) and copper (II) soaps. For the pure rhodium soaps, the columns are shown to result from the stacking of binuclear metal-metal bonded dirhodium tetracarboxylate units bonded to one another by apical ligation of the metal atom of each complex with one of the oxygen atoms of the adjacent molecule. Mixtures of rhodium (II) and copper (II) soaps give a hexagonal columnar mesophase in which pure rhodium and pure copper columns are randomly distributed.

Coarse-grained modelling of triglyceride crystallisation: a molecular insight into tripalmitin tristearin binary mixtures by molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Pizzirusso, Antonio; Brasiello, Antonio; De Nicola, Antonio; Marangoni, Alejandro G.; Milano, Giuseppe

2015-12-01

The first simulation study of the crystallisation of a binary mixture of triglycerides using molecular dynamics simulations is reported. Coarse-grained models of tristearin (SSS) and tripalmitin (PPP) molecules have been considered. The models have been preliminarily tested in the crystallisation of pure SSS and PPP systems. Two different quenching procedures have been tested and their performances have been analysed. The structures obtained from the crystallisation procedures show a high orientation order and a high content of molecules in the tuning fork conformation, comparable with the crystalline α phase. The behaviour of melting temperatures for the α phase of the mixture SSS/PPP obtained from the simulations is in qualitative agreement with the behaviour that was experimentally determined.

Odourant dominance in olfactory mixture processing: what makes a strong odourant?

PubMed Central

Schubert, Marco; Sandoz, Jean-Christophe; Galizia, Giovanni; Giurfa, Martin

2015-01-01

The question of how animals process stimulus mixtures remains controversial as opposing views propose that mixtures are processed analytically, as the sum of their elements, or holistically, as unique entities different from their elements. Overshadowing is a widespread phenomenon that can help decide between these alternatives. In overshadowing, an individual trained with a binary mixture learns one element better at the expense of the other. Although element salience (learning success) has been suggested as a main explanation for overshadowing, the mechanisms underlying this phenomenon remain unclear. We studied olfactory overshadowing in honeybees to uncover the mechanisms underlying olfactory-mixture processing. We provide, to our knowledge, the most comprehensive dataset on overshadowing to date based on 90 experimental groups involving more than 2700 bees trained either with six odourants or with their resulting 15 binary mixtures. We found that bees process olfactory mixtures analytically and that salience alone cannot predict overshadowing. After normalizing learning success, we found that an unexpected feature, the generalization profile of an odourant, was determinant for overshadowing. Odourants that induced less generalization enhanced their distinctiveness and became dominant in the mixture. Our study thus uncovers features that determine odourant dominance within olfactory mixtures and allows the referring of this phenomenon to differences in neural activity both at the receptor and the central level in the insect nervous system. PMID:25652840

Long-time tails of the green-kubo integrands for a binary mixture

NASA Astrophysics Data System (ADS)

Wood, W. W.

1989-11-01

The long-time tails for the mutual diffusion coefficient, the thermal diffusivity, the thermal conductivity, and the shear and longitudinal viscosities (from which the tail of the bulk viscosity can be calculated) of a nonreactive binary mixture are calculated from mode-coupling theory, and compared with a prior calculation by Pomeau. Three different choices of the thermal forces and currents are considered, with the results found to take their simplest form in the case of the de Groot "double-primed set". The decompositions into the kinetic, potential, and cross terms are given.

Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H₂ Mixture.

PubMed

Hirota, Yuichiro; Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

2017-08-03

In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H₂/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H₂ (>17,000) in a binary mixture system based on a solution-diffusion mechanism with improved durability over the supported ionic liquid membrane.

Solidification of a binary mixture

NASA Technical Reports Server (NTRS)

Antar, B. N.

1982-01-01

The time dependent concentration and temperature profiles of a finite layer of a binary mixture are investigated during solidification. The coupled time dependent Stefan problem is solved numerically using an implicit finite differencing algorithm with the method of lines. Specifically, the temporal operator is approximated via an implicit finite difference operator resulting in a coupled set of ordinary differential equations for the spatial distribution of the temperature and concentration for each time. Since the resulting differential equations set form a boundary value problem with matching conditions at an unknown spatial point, the method of invariant imbedding is used for its solution.

Dynamic heterogeneities and non-Gaussian behavior in two-dimensional randomly confined colloidal fluids

NASA Astrophysics Data System (ADS)

Schnyder, Simon K.; Skinner, Thomas O. E.; Thorneywork, Alice L.; Aarts, Dirk G. A. L.; Horbach, Jürgen; Dullens, Roel P. A.

2017-03-01

A binary mixture of superparamagnetic colloidal particles is confined between glass plates such that the large particles become fixed and provide a two-dimensional disordered matrix for the still mobile small particles, which form a fluid. By varying fluid and matrix area fractions and tuning the interactions between the superparamagnetic particles via an external magnetic field, different regions of the state diagram are explored. The mobile particles exhibit delocalized dynamics at small matrix area fractions and localized motion at high matrix area fractions, and the localization transition is rounded by the soft interactions [T. O. E. Skinner et al., Phys. Rev. Lett. 111, 128301 (2013), 10.1103/PhysRevLett.111.128301]. Expanding on previous work, we find the dynamics of the tracers to be strongly heterogeneous and show that molecular dynamics simulations of an ideal gas confined in a fixed matrix exhibit similar behavior. The simulations show how these soft interactions make the dynamics more heterogeneous compared to the disordered Lorentz gas and lead to strong non-Gaussian fluctuations.

Densities of aqueous blended amines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, C.H.; Li, M.H.

1997-05-01

Solutions of alkanolamines are an industrially important class of compounds used in the natural gas and synthetic ammonia industries and petroleum chemical plants for the removal of CO{sub 2} and H{sub 2}S from gas streams. The densities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA) + water, DEA + 2-amino-2-methyl-1-propanol (AMP) + water, and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) + water were measured from 30 C to 80 C. A Redlich-Kister equation of the excess volume was applied to represent the density. Based on the available density data for five ternary systems: MEA + MDEA + H{sub 2}O, MEAmore » + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. The density calculations show quite satisfactory results. The overall average absolute percent deviation is about 0.04% for a total of 686 data points.« less

Viscosities of aqueous blended amines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, C.H.; Li, M.H.

1997-07-01

Solutions of alkanolamines are an industrially important class of compounds used in the natural gas, oil refineries, petroleum chemical plants, and synthetic ammonia industries for the removal of acidic components like CO{sub 2} and H{sub 2}S from gas streams. The viscosities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA), DEA + 2-amino-2-methyl-1-propanol (AMP), and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) were measured from 30 C to 80 C. A Redlich-Kister equation for the viscosity deviation was applied to represent the viscosity. On the basis of the available viscosity data for five ternary systems, MEA + MDEA + H{sub 2}O, MEAmore » + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. For the viscosity calculation of the systems tested, the overall average absolute percent deviation is about 1.0% for a total of 499 data points.« less

Effects of oxygen content on the oxidation process of Si-containing steel during anisothermal heating

NASA Astrophysics Data System (ADS)

Yuan, Qing; Xu, Guang; Liang, Wei-cheng; He, Bei; Zhou, Ming-xing

2018-02-01

The oxidizing behavior of Si-containing steel was investigated in an O2 and N2 binary-component gas with oxygen contents ranging between 0.5vol% and 4.0vol% under anisothermal-oxidation conditions. A simultaneous thermal analyzer was employed to simulate the heating process of Si-containing steel in industrial reheating furnaces. The oxidation gas mixtures were introduced from the commencement of heating. The results show that the oxidizing rate remains constant in the isothermal holding process at high temperatures; therefore, the mass change versus time presents a linear law. A linear relation also exists between the oxidizing rate and the oxygen content. Using the linear regression equation, the oxidation rate at different oxygen contents can be predicted. In addition, the relationship between the total mass gain and the oxygen content is linear; thus, the total mass gain at oxygen contents between 0.5vol%-4.0vol% can be determined. These results enrich the theoretical studies of the oxidation process in Si-containing steels.

Toxicity of binary mixtures of metal oxide nanoparticles to Nitrosomonas europaea.

PubMed

Yu, Ran; Wu, Junkang; Liu, Meiting; Zhu, Guangcan; Chen, Lianghui; Chang, Yan; Lu, Huijie

2016-06-01

Although the widely used metal oxide nanoparticles (NPs) titanium dioxide NPs (n-TiO2), cerium dioxide NPs (n-CeO2), and zinc oxide NPs (n-ZnO) have been well known for their potential cytotoxicities to environmental organisms, their combined effects have seldom been investigated. In this study, the short-term binary effect of n-CeO2 and n-TiO2 or n-ZnO on a model ammonia oxidizing bacterium, Nitrosomonas europaea were evaluated based on the examinations of cells' physiological, metabolic, and transcriptional responses. The addition of n-TiO2 mitigated the negative effect of more toxic n-CeO2 and the binary toxicity (antagonistic toxicity) of n-TiO2 and n-CeO2 was generally lower than the single NPs induced one. While the n-CeO2/n-ZnO mixture exerted higher cytotoxicity (synergistic cytotoxicity) than that from single NPs. The increased addition of the less toxic n-CeO2 exaggerated the binary toxicity of n-CeO2/n-ZnO mixture although the solubility of n-ZnO was not significantly affected, which excluded the contribution of the dissolved Zn ions to the enhancement of the combined cytotoxicity. The cell membrane disturbances and NP internalizations were detected for all the NP impacted cultures and the electrostatic interactions among the two distinct NPs and the cells were expected to play a key role in mediating their direct contacts and the eventual binary nanotoxicity to the cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic–inorganic binary mixture matrix for comprehensive laser-desorption ionization mass spectrometric analysis and imaging of medium-size molecules including phospholipids, glycerolipids, and oligosaccharides

DOE PAGES

Feenstra, Adam D.; Ames Lab., Ames, IA; O'Neill, Kelly C.; ...

2016-10-13

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a widely adopted, versatile technique, especially in high-throughput analysis and imaging. However, matrix-dependent selectivity of analytes is often a severe limitation. In this work, a mixture of organic 2,5-dihydroxybenzoic acid and inorganic Fe 3O 4 nanoparticles is developed as a binary MALDI matrix to alleviate the well-known issue of triacylglycerol (TG) ion suppression by phosphatidylcholine (PC). In application to lipid standards and maize seed cross-sections, the binary matrix not only dramatically reduced the ion suppression of TG, but also efficiently desorbed and ionized a wide variety of lipids such as cationic PC, anionicmore » phosphatidylethanolamine (PE) and phosphatidylinositol (PI), and neutral digalactosyldiacylglycerol (DGDG). The binary matrix was also very efficient for large polysaccharides, which were not detected by either of the individual matrices. As a result, the usefulness of the binary matrix is demonstrated in MS imaging of maize seed sections, successfully visualizing diverse medium-size molecules and acquiring high-quality MS/MS spectra for these compounds.« less

Experimental evidence for excess entropy discontinuities in glass-forming solutions.

PubMed

Lienhard, Daniel M; Zobrist, Bernhard; Zuend, Andreas; Krieger, Ulrich K; Peter, Thomas

2012-02-21

Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T(g). The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account. © 2012 American Institute of Physics

Recovery of nitrogen and light hydrocarbons from polyalkene purge gas

DOEpatents

Zwilling, Daniel Patrick; Golden, Timothy Christoph; Weist, Jr., Edward Landis; Ludwig, Keith Alan

2003-06-10

A method for the separation of a gas mixture comprises (a) obtaining a feed gas mixture comprising nitrogen and at least one hydrocarbon having two to six carbon atoms; (b) introducing the feed gas mixture at a temperature of about 60.degree. F. to about 105.degree. F. into an adsorbent bed containing adsorbent material which selectively adsorbs the hydrocarbon, and withdrawing from the adsorbent bed an effluent gas enriched in nitrogen; (c) discontinuing the flow of the feed gas mixture into the adsorbent bed and depressurizing the adsorbent bed by withdrawing depressurization gas therefrom; (d) purging the adsorbent bed by introducing a purge gas into the bed and withdrawing therefrom an effluent gas comprising the hydrocarbon, wherein the purge gas contains nitrogen at a concentration higher than that of the nitrogen in the feed gas mixture; (e) pressurizing the adsorbent bed by introducing pressurization gas into the bed; and (f) repeating (b) through (e) in a cyclic manner.

Low Mach number fluctuating hydrodynamics of multispecies liquid mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donev, Aleksandar, E-mail: donev@courant.nyu.edu; Bhattacharjee, Amit Kumar; Nonaka, Andy

We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure, which generalizes our prior work on ideal mixtures of ideal gases [Balakrishnan et al., “Fluctuating hydrodynamics of multispecies nonreactive mixtures,” Phys. Rev. E 89 013017 (2014)] and binary liquid mixtures [Donev et al., “Low mach number fluctuating hydrodynamics of diffusively mixing fluids,” Commun. Appl. Math. Comput. Sci. 9(1), 47-105 (2014)]. In this formulation, we combine and extend a number of existing descriptions of multispecies transport available in the literature. Themore » formulation applies to non-ideal mixtures of arbitrary number of species, without the need to single out a “solvent” species, and includes contributions to the diffusive mass flux due to gradients of composition, temperature, and pressure. Momentum transport and advective mass transport are handled using a low Mach number approach that eliminates fast sound waves (pressure fluctuations) from the full compressible system of equations and leads to a quasi-incompressible formulation. Thermal fluctuations are included in our fluctuating hydrodynamics description following the principles of nonequilibrium thermodynamics. We extend the semi-implicit staggered-grid finite-volume numerical method developed in our prior work on binary liquid mixtures [Nonaka et al., “Low mach number fluctuating hydrodynamics of binary liquid mixtures,” http://arxiv.org/abs/1410.2300 (2015)] and use it to study the development of giant nonequilibrium concentration fluctuations in a ternary mixture subjected to a steady concentration gradient. We also numerically study the development of diffusion-driven gravitational instabilities in a ternary mixture and compare our numerical results to recent experimental measurements [Carballido-Landeira et al., “Mixed-mode instability of a miscible interface due to coupling between Rayleigh–Taylor and double-diffusive convective modes,” Phys. Fluids 25, 024107 (2013)] in a Hele-Shaw cell. We find that giant nonequilibrium fluctuations can trigger the instability but are eventually dominated by the deterministic growth of the unstable mode, in both quasi-two-dimensional (Hele-Shaw) and fully three-dimensional geometries used in typical shadowgraph experiments.« less

Cumulative Effects of In Utero Administration of Mixtures of Reproductive Toxicants that Disrupt Common Target Tissues via Diverse Mechanisms of Toxicity

PubMed Central

Rider, Cynthia V.; Furr, Johnathan R.; Wilson, Vickie S.; Gray, L. Earl

2010-01-01

Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the end goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described in detail. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs at dosage levels equivalent to approximately one half of the ED50 for hypospadias or epididymal agenesis. The binary mixtures included: androgen receptor (AR) antagonists (vinclozolin plus procymidone), phthalate esters (DBP plus BBP and DEHP plus DBP), a phthalate ester plus an AR antagonist (DBP plus procymidone), a mixed mechanism androgen signaling disruptor (linuron) plus BBP, and two chemicals which disrupt epididymal differentiation through entirely different toxicity pathways: DBP (AR pathway) plus 2,3,7,8 TCDD (AhR pathway). We also conducted multi-component mixture studies combining several “antiandrogens” together. In the first study, seven chemicals (four pesticides and three phthalates) that elicit antiandrogenic effects at two different sites in the androgen signaling pathway (i.e. AR antagonist or inhibition of androgen synthesis) were combined. In the second study, three additional phthalates were added to make a ten chemical mixture. In both the binary mixture studies and the multi-component mixture studies, chemicals that targeted male reproductive tract development displayed cumulative effects that exceeded predictions based upon a response addition model and most often were in accordance with predictions based upon dose addition models. In summary, our results indicate that compounds that act by disparate mechanisms of toxicity to disrupt the dynamic interactions among the interconnected signaling pathways in differentiating tissues produce cumulative dose-additive effects, regardless of the mechanism or mode of action of the individual mixture component. PMID:20487044

Gas mixtures for spark gap closing switches

DOEpatents

Christophorou, L.G.; McCorkle, D.L.; Hunter, S.R.

1987-02-20

Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches. 6 figs.

COSMO-RS analysis on mixing properties obtained for the systems 1-butyl-X-methylpyridinium tetrafluoroborate [X = 2,3,4] and 1,ω-dibromoalkanes [ω = 1-6].

PubMed

Navas, Ana; Ortega, Juan; Palomar, José; Díaz, Carlos; Vreekamp, Remko

2011-05-07

A theoretical-experimental study for a set of 18 binary systems comprised of [bXmpy][BF(4)] (X=2-4) + 1,ω-Br(CH(2))(v)Br (v =ω=1-6) at a temperature of 298.15 K is presented. The solubility curves are determined for each binary system, establishing the intervals of measurement for the excess properties, H(E)(m) and V(E)(m). These properties are then determined for those systems that present a miscibility zone. Binary systems containing 1,ω-dibromoalkanes with ω=5,6 present reduced solubility intervals at the temperature of 298.15 K. However, the mixtures with 1,1-dibromomethane were totally miscible with the three isomers of 1-butyl-X-methylpyridinium tetrafluoroborate. Mixtures with dibromomethane present H(E)(m) <0, whereas H(E)(m) >0 for the other binary systems. Sigmoidal curves were observed for the V(E)(m) describing expansion and contraction processes for all the systems, except for the mixtures of [b2mpy][BF(4)] with the smaller dibromoalkanes, which present contraction effects. The COSMO-RS methodology was used to estimate the solubilities and the intermolecular interaction energies, giving an acceptable explanation of the behavioral structure of pure compounds and solutions. This journal is © the Owner Societies 2011

Benzoic Acid and Chlorobenzoic Acids: Thermodynamic Study of the Pure Compounds and Binary Mixtures With Water.

PubMed

Reschke, Thomas; Zherikova, Kseniya V; Verevkin, Sergey P; Held, Christoph

2016-03-01

Benzoic acid is a model compound for drug substances in pharmaceutical research. Process design requires information about thermodynamic phase behavior of benzoic acid and its mixtures with water and organic solvents. This work addresses phase equilibria that determine stability and solubility. In this work, Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the phase behavior of aqueous and organic solutions containing benzoic acid and chlorobenzoic acids. Absolute vapor pressures of benzoic acid and 2-, 3-, and 4-chlorobenzoic acid from literature and from our own measurements were used to determine pure-component PC-SAFT parameters. Two binary interaction parameters between water and/or benzoic acid were used to model vapor-liquid and liquid-liquid equilibria of water and/or benzoic acid between 280 and 413 K. The PC-SAFT parameters and 1 binary interaction parameter were used to model aqueous solubility of the chlorobenzoic acids. Additionally, solubility of benzoic acid in organic solvents was predicted without using binary parameters. All results showed that pure-component parameters for benzoic acid and for the chlorobenzoic acids allowed for satisfying modeling phase equilibria. The modeling approach established in this work is a further step to screen solubility and to predict the whole phase region of mixtures containing pharmaceuticals. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

A nonlinear isobologram model with Box-Cox transformation to both sides for chemical mixtures.

PubMed

Chen, D G; Pounds, J G

1998-12-01

The linear logistical isobologram is a commonly used and powerful graphical and statistical tool for analyzing the combined effects of simple chemical mixtures. In this paper a nonlinear isobologram model is proposed to analyze the joint action of chemical mixtures for quantitative dose-response relationships. This nonlinear isobologram model incorporates two additional new parameters, Ymin and Ymax, to facilitate analysis of response data that are not constrained between 0 and 1, where parameters Ymin and Ymax represent the minimal and the maximal observed toxic response. This nonlinear isobologram model for binary mixtures can be expressed as [formula: see text] In addition, a Box-Cox transformation to both sides is introduced to improve the goodness of fit and to provide a more robust model for achieving homogeneity and normality of the residuals. Finally, a confidence band is proposed for selected isobols, e.g., the median effective dose, to facilitate graphical and statistical analysis of the isobologram. The versatility of this approach is demonstrated using published data describing the toxicity of the binary mixtures of citrinin and ochratoxin as well as a new experimental data from our laboratory for mixtures of mercury and cadmium.

A nonlinear isobologram model with Box-Cox transformation to both sides for chemical mixtures.

PubMed Central

Chen, D G; Pounds, J G

1998-01-01

The linear logistical isobologram is a commonly used and powerful graphical and statistical tool for analyzing the combined effects of simple chemical mixtures. In this paper a nonlinear isobologram model is proposed to analyze the joint action of chemical mixtures for quantitative dose-response relationships. This nonlinear isobologram model incorporates two additional new parameters, Ymin and Ymax, to facilitate analysis of response data that are not constrained between 0 and 1, where parameters Ymin and Ymax represent the minimal and the maximal observed toxic response. This nonlinear isobologram model for binary mixtures can be expressed as [formula: see text] In addition, a Box-Cox transformation to both sides is introduced to improve the goodness of fit and to provide a more robust model for achieving homogeneity and normality of the residuals. Finally, a confidence band is proposed for selected isobols, e.g., the median effective dose, to facilitate graphical and statistical analysis of the isobologram. The versatility of this approach is demonstrated using published data describing the toxicity of the binary mixtures of citrinin and ochratoxin as well as a new experimental data from our laboratory for mixtures of mercury and cadmium. PMID:9860894

Mixtures of charged colloid and neutral polymer: Influence of electrostatic interactions on demixing and interfacial tension

NASA Astrophysics Data System (ADS)

Denton, Alan R.; Schmidt, Matthias

2005-06-01

The equilibrium phase behavior of a binary mixture of charged colloids and neutral, nonadsorbing polymers is studied within free-volume theory. A model mixture of charged hard-sphere macroions and ideal, coarse-grained, effective-sphere polymers is mapped first onto a binary hard-sphere mixture with nonadditive diameters and then onto an effective Asakura-Oosawa model [S. Asakura and F. Oosawa, J. Chem. Phys. 22, 1255 (1954)]. The effective model is defined by a single dimensionless parameter—the ratio of the polymer diameter to the effective colloid diameter. For high salt-to-counterion concentration ratios, a free-volume approximation for the free energy is used to compute the fluid phase diagram, which describes demixing into colloid-rich (liquid) and colloid-poor (vapor) phases. Increasing the range of electrostatic interactions shifts the demixing binodal toward higher polymer concentration, stabilizing the mixture. The enhanced stability is attributed to a weakening of polymer depletion-induced attraction between electrostatically repelling macroions. Comparison with predictions of density-functional theory reveals a corresponding increase in the liquid-vapor interfacial tension. The predicted trends in phase stability are consistent with observed behavior of protein-polysaccharide mixtures in food colloids.

The effect of vapor polarity and boiling point on breakthrough for binary mixtures on respirator carbon.

PubMed

Robbins, C A; Breysse, P N

1996-08-01

This research evaluated the effect of the polarity of a second vapor on the adsorption of a polar and a nonpolar vapor using the Wheeler model. To examine the effect of polarity, it was also necessary to observe the effect of component boiling point. The 1% breakthrough time (1% tb), kinetic adsorption capacity (W(e)), and rate constant (kv) of the Wheeler model were determined for vapor challenges on carbon beds for both p-xylene and pyrrole (referred to as test vapors) individually, and in equimolar binary mixtures with the polar and nonpolar vapors toluene, p-fluorotoluene, o-dichlorobenzene, and p-dichlorobenzene (referred to as probe vapors). Probe vapor polarity (0 to 2.5 Debye) did not systematically alter the 1% tb, W(e), or kv of the test vapors. The 1% tb and W(e) for test vapors in binary mixtures can be estimated reasonably well, using the Wheeler model, from single-vapor data (1% tb +/- 30%, W(e) +/- 20%). The test vapor 1% tb depended mainly on total vapor concentration in both single and binary systems. W(e) was proportional to test vapor fractional molar concentration (mole fraction) in mixtures. The kv for p-xylene was significantly different (p < or = 0.001) when compared according to probe boiling point; however, these differences were apparently of limited importance in estimating 1% tb for the range of boiling points tested (111 to 180 degrees C). Although the polarity and boiling point of chemicals in the range tested are not practically important in predicting 1% tb with the Wheeler model, an effect due to probe boiling point is suggested, and tests with chemicals of more widely ranging boiling point are warranted. Since the 1% tb, and thus, respirator service life, depends mainly on total vapor concentration, these data underscore the importance of taking into account the presence of other vapors when estimating respirator service life for a vapor in a mixture.

Differentiation of Chemical Components in a Binary Solvent Vapor Mixture Using Carbon/Polymer Composite-Based Chemiresistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Sanjay V.; Jenkins, Mark W.; Hughes, Robert C.

1999-07-19

We demonstrate a ''universal solvent sensor'' constructed from a small array of carbon/polymer composite chemiresistors that respond to solvents spanning a wide range of Hildebrand volubility parameters. Conductive carbon particles provide electrical continuity in these composite films. When the polymer matrix absorbs solvent vapors, the composite film swells, the average separation between carbon particles increases, and an increase in film resistance results, as some of the conduction pathways are broken. The adverse effects of contact resistance at high solvent concentrations are reported. Solvent vapors including isooctane, ethanol, dlisopropyhnethylphosphonate (DIMP), and water are correctly identified (''classified'') using three chemiresistors, their compositemore » coatings chosen to span the full range of volubility parameters. With the same three sensors, binary mixtures of solvent vapor and water vapor are correctly classified, following classification, two sensors suffice to determine the concentrations of both vapor components. Polyethylene vinylacetate and polyvinyl alcohol (PVA) are two such polymers that are used to classify binary mixtures of DIMP with water vapor; the PVA/carbon-particle-composite films are sensitive to less than 0.25{degree}A relative humidity. The Sandia-developed VERI (Visual-Empirical Region of Influence) technique is used as a method of pattern recognition to classify the solvents and mixtures and to distinguish them from water vapor. In many cases, the response of a given composite sensing film to a binary mixture deviates significantly from the sum of the responses to the isolated vapor components at the same concentrations. While these nonlinearities pose significant difficulty for (primarily) linear methods such as principal components analysis, VERI handles both linear and nonlinear data with equal ease. In the present study the maximum speciation accuracy is achieved by an array containing three or four sensor elements, with the addition of more sensors resulting in a measurable accuracy decrease.« less

Investigating the discrimination potential of linear and nonlinear spectral multivariate calibrations for analysis of phenolic compounds in their binary and ternary mixtures and calculation pKa values.

PubMed

Rasouli, Zolaikha; Ghavami, Raouf

2016-08-05

Vanillin (VA), vanillic acid (VAI) and syringaldehyde (SIA) are important food additives as flavor enhancers. The current study for the first time is devote to the application of partial least square (PLS-1), partial robust M-regression (PRM) and feed forward neural networks (FFNNs) as linear and nonlinear chemometric methods for the simultaneous detection of binary and ternary mixtures of VA, VAI and SIA using data extracted directly from UV-spectra with overlapped peaks of individual analytes. Under the optimum experimental conditions, for each compound a linear calibration was obtained in the concentration range of 0.61-20.99 [LOD=0.12], 0.67-23.19 [LOD=0.13] and 0.73-25.12 [LOD=0.15] μgmL(-1) for VA, VAI and SIA, respectively. Four calibration sets of standard samples were designed by combination of a full and fractional factorial designs with the use of the seven and three levels for each factor for binary and ternary mixtures, respectively. The results of this study reveal that both the methods of PLS-1 and PRM are similar in terms of predict ability each binary mixtures. The resolution of ternary mixture has been accomplished by FFNNs. Multivariate curve resolution-alternating least squares (MCR-ALS) was applied for the description of spectra from the acid-base titration systems each individual compound, i.e. the resolution of the complex overlapping spectra as well as to interpret the extracted spectral and concentration profiles of any pure chemical species identified. Evolving factor analysis (EFA) and singular value decomposition (SVD) were used to distinguish the number of chemical species. Subsequently, their corresponding dissociation constants were derived. Finally, FFNNs has been used to detection active compounds in real and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigating the discrimination potential of linear and nonlinear spectral multivariate calibrations for analysis of phenolic compounds in their binary and ternary mixtures and calculation pKa values

NASA Astrophysics Data System (ADS)

Rasouli, Zolaikha; Ghavami, Raouf

2016-08-01

Vanillin (VA), vanillic acid (VAI) and syringaldehyde (SIA) are important food additives as flavor enhancers. The current study for the first time is devote to the application of partial least square (PLS-1), partial robust M-regression (PRM) and feed forward neural networks (FFNNs) as linear and nonlinear chemometric methods for the simultaneous detection of binary and ternary mixtures of VA, VAI and SIA using data extracted directly from UV-spectra with overlapped peaks of individual analytes. Under the optimum experimental conditions, for each compound a linear calibration was obtained in the concentration range of 0.61-20.99 [LOD = 0.12], 0.67-23.19 [LOD = 0.13] and 0.73-25.12 [LOD = 0.15] μg mL- 1 for VA, VAI and SIA, respectively. Four calibration sets of standard samples were designed by combination of a full and fractional factorial designs with the use of the seven and three levels for each factor for binary and ternary mixtures, respectively. The results of this study reveal that both the methods of PLS-1 and PRM are similar in terms of predict ability each binary mixtures. The resolution of ternary mixture has been accomplished by FFNNs. Multivariate curve resolution-alternating least squares (MCR-ALS) was applied for the description of spectra from the acid-base titration systems each individual compound, i.e. the resolution of the complex overlapping spectra as well as to interpret the extracted spectral and concentration profiles of any pure chemical species identified. Evolving factor analysis (EFA) and singular value decomposition (SVD) were used to distinguish the number of chemical species. Subsequently, their corresponding dissociation constants were derived. Finally, FFNNs has been used to detection active compounds in real and spiked water samples.

Composition inversion in mixtures of binary colloids and polymer

NASA Astrophysics Data System (ADS)

Zhang, Isla; Pinchaipat, Rattachai; Wilding, Nigel B.; Faers, Malcolm A.; Bartlett, Paul; Evans, Robert; Royall, C. Patrick

2018-05-01

Understanding the phase behaviour of mixtures continues to pose challenges, even for systems that might be considered "simple." Here, we consider a very simple mixture of two colloidal and one non-adsorbing polymer species, which can be simplified even further to a size-asymmetrical binary mixture, in which the effective colloid-colloid interactions depend on the polymer concentration. We show that this basic system exhibits surprisingly rich phase behaviour. In particular, we enquire whether such a system features only a liquid-vapor phase separation (as in one-component colloid-polymer mixtures) or whether, additionally, liquid-liquid demixing of two colloidal phases can occur. Particle-resolved experiments show demixing-like behaviour, but when combined with bespoke Monte Carlo simulations, this proves illusory, and we reveal that only a single liquid-vapor transition occurs. Progressive migration of the small particles to the liquid phase as the polymer concentration increases gives rise to composition inversion—a maximum in the large particle concentration in the liquid phase. Close to criticality, the density fluctuations are found to be dominated by the larger colloids.

Original predictive approach to the compressibility of pharmaceutical powder mixtures based on the Kawakita equation.

PubMed

Mazel, Vincent; Busignies, Virginie; Duca, Stéphane; Leclerc, Bernard; Tchoreloff, Pierre

2011-05-30

In the pharmaceutical industry, tablets are obtained by the compaction of two or more components which have different physical properties and compaction behaviours. Therefore, it could be interesting to predict the physical properties of the mixture using the single-component results. In this paper, we have focused on the prediction of the compressibility of binary mixtures using the Kawakita model. Microcrystalline cellulose (MCC) and L-alanine were compacted alone and mixed at different weight fractions. The volume reduction, as a function of the compaction pressure, was acquired during the compaction process ("in-die") and after elastic recovery ("out-of-die"). For the pure components, the Kawakita model is well suited to the description of the volume reduction. For binary mixtures, an original approach for the prediction of the volume reduction without using the effective Kawakita parameters was proposed and tested. The good agreement between experimental and predicted data proved that this model was efficient to predict the volume reduction of MCC and L-alanine mixtures during compaction experiments. Copyright © 2011 Elsevier B.V. All rights reserved.

Trophic transfer potential of two different crystalline phases of TiO2 NPs from Chlorella sp. to Ceriodaphnia dubia.

PubMed

Iswarya, V; Bhuvaneshwari, M; Chandrasekaran, N; Mukherjee, Amitava

2018-04-01

Owing to the increase in the usage of titanium dioxide nanoparticles (TiO 2 NPs), their release into the aquatic environment is inevitable. In the aquatic ecosystem, TiO 2 NPs can bio-magnify at various trophic levels in the food chain through dietary exposure. In the current study, the trophic transfer potential of two crystalline phases of TiO 2, anatase and rutile nanoparticles (individual as well as a binary mixture) has been evaluated in the lake water matrix using algae-daphnia system. Chlorella sp. and Ceriodaphnia dubia were used as test organisms to represent the algae-daphnia food chain of the freshwater ecosystem. Other than crystallinity, the effect of irradiation (visible and UV-A) was also investigated at the test concentrations, 75, 300, and 1200 μM. TiO 2 NPs treated algal diet produced significant mortality only at the test concentrations, 300 and 1200 μM. The type of irradiation and crystallinity doesn't have any impact on the mortality of daphnids through the dietary exposure of TiO 2 NPs. Comparing the mixture with individual NPs, binary mixture induced less mortality on C. dubia which signifies the antagonistic effect of NPs when they coexist. Statistical modeling confirmed the antagonistic effect of the binary mixture on C. dubia. As individual NPs, anatase and rutile forms showed a maximum Ti accumulation under UV-A and visible irradiation, respectively. BMF of TiO 2 NPs has been in validation with the bioaccumulation noted in C. dubia. Individual NPs (75 μM) showed higher BMF value of ∼23 under both UV-A (anatase) and visible (rutile) irradiation. Individual NPs showing higher BMF confirmed their trophic transfer potential in the aquatic food chain, primarily through the diet. In contrast, the binary mixture obtained a higher BMF of 1.9 and 0.79 at 75 and 300 μM under visible and UV-A irradiation, respectively. The plausible reason behind this decrement was the antagonistic effect of the mixture which significantly reduced their Ti bioaccumulation on C. dubia. Copyright © 2018 Elsevier B.V. All rights reserved.

Waste gas storage

NASA Technical Reports Server (NTRS)

Vickers, Brian D. (Inventor)

1994-01-01

Method for storing a waste gas mixture comprised of nitrogen, oxygen, carbon dioxide, and inert gases, the gas mixture containing corrosive contaminants including inorganic acids and bases and organic solvents, and derived from space station operations. The gas mixture is stored under pressure in a vessel formed of a filament wound composite overwrap on a metal liner, the metal liner being pre-stressed in compression by the overwrap, thereby avoiding any tensile stress in the liner, and preventing stress corrosion cracking of the liner during gas mixture storage.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khinkis, Mark J.; Kozlov, Aleksandr P.

A radiant, non-catalytic recuperative reformer has a flue gas flow path for conducting hot exhaust gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is positioned adjacent to the flue gas flow path to permit heat transfer from the hot exhaust gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorificmore » fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, a portion of the reforming mixture flow path is positioned outside of flue gas flow path for a relatively large residence time.« less

Recommended direct simulation Monte Carlo collision model parameters for modeling ionized air transport processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaminathan-Gopalan, Krishnan; Stephani, Kelly A., E-mail: ksteph@illinois.edu

2016-02-15

A systematic approach for calibrating the direct simulation Monte Carlo (DSMC) collision model parameters to achieve consistency in the transport processes is presented. The DSMC collision cross section model parameters are calibrated for high temperature atmospheric conditions by matching the collision integrals from DSMC against ab initio based collision integrals that are currently employed in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and Data Parallel Line Relaxation (DPLR) high temperature computational fluid dynamics solvers. The DSMC parameter values are computed for the widely used Variable Hard Sphere (VHS) and the Variable Soft Sphere (VSS) models using the collision-specific pairing approach.more » The recommended best-fit VHS/VSS parameter values are provided over a temperature range of 1000-20 000 K for a thirteen-species ionized air mixture. Use of the VSS model is necessary to achieve consistency in transport processes of ionized gases. The agreement of the VSS model transport properties with the transport properties as determined by the ab initio collision integral fits was found to be within 6% in the entire temperature range, regardless of the composition of the mixture. The recommended model parameter values can be readily applied to any gas mixture involving binary collisional interactions between the chemical species presented for the specified temperature range.« less

Laboratory IR Studies and Astrophysical Implications of C2H2-Containing Binary Ices

NASA Technical Reports Server (NTRS)

Knez, C.; Moore, M.; Ferrante, R.; Hudson, R.

2012-01-01

Studies of molecular hot cores and protostellar environments have shown that the observed abundance of gas-phase acetylene (C2H2) cannot be matched by chemical models without the inclusion of C2H2 molecules subliming from icy grain mantles. Searches for infrared (IR) spectral features of solid-phase acetylene are under way, but few laboratory reference spectra of C2H2 in icy mixtures, which are needed for spectral fits to observational data, have been published. Here, we report a systematic study of the IR spectra of condensed-phase pure acetylene and acetylene in ices dominated by carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water (H2O). We present new spectral data for these ices, including band positions and intrinsic band strengths. For each ice mixture and concentration, we also explore the dependence of acetylene's nu5-band position (743 cm-1, 13.46 micrometers) and FWHM on temperature. Our results show that the nu5 feature is much more cleanly resolved in ices dominated by non-polar and low-polarity molecules, specifically CO, CO2, and CH4, than in mixtures dominated by H2O-ice. We compare our laboratory ice spectra with observations of a quiescent region in Serpens.

[CuCl(n)](2-n) ion-pair species in 1-ethyl-3-methylimidazolium chloride ionic liquid-water mixtures: ultraviolet-visible, X-ray absorption fine structure, and density functional theory characterization.

PubMed

Li, Guosheng; Camaioni, Donald M; Amonette, James E; Zhang, Z Conrad; Johnson, Timothy J; Fulton, John L

2010-10-07

We studied the coordination environment about Cu(II) in a pure ionic liquid, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl), and in binary mixtures of this compound with water across the entire range of compositions, using a combination of X-ray absorption fine structure (XAFS), ultraviolet-visible (UV-vis) spectroscopy, and electronic structure calculations. Our results show a series of stages in the ion pairing of the divalent cation, Cu(II), including the contact ion pairing of Cu(2+) with multiple Cl(-) ligands to form various CuCl(n)((2-n)) polyanions, as well as the subsequent solvation and ion pairing of the polychlorometallate anion with the EMIM(+) cation. Ion-pair formation is strongly promoted in [EMIM]Cl by the low dielectric constant and by the extensive breakdown of the water hydrogen-bond network in [EMIM]Cl-water mixtures. The CuCl(4)(2-) species dominates in the [EMIM]Cl solvent, and calculations along with spectroscopy show that its geometry distorts to C(2) symmetry compared to D(2d) in the gas phase. These results are important in understanding catalysis and separation processes involving transition metals in ionic liquid systems.

Coupling Flash LC with MS for enrichment and isolation of milk oligosaccharides for functional studies

PubMed Central

Strum, John S.; Aldredge, Danielle; Barile, Daniela; Lebrilla, Carlito B.

2013-01-01

Mass spectrometry has been coupled with flash liquid chromatography to yield new capabilities for isolating non-chromophoric material from complicated biological mixtures. A flash LC/MS/MS method enabled fraction collection of milk oligosaccharides from biological mixtures based on composition and structure. The method is compatible with traditional gas-pressure driven flow flash chromatography, widely employed in organic chemistry laboratories. The on-line mass detector enabled real-time optimization of chromatographic parameters to favor separation of oligosaccharides that would otherwise be indistinguishable from co-eluting components with a non-specific detector. Unlike previously described preparative LC/MS techniques, we have employed a dynamic flow connection that permits any flow rate from the flash system to be delivered from 1–200 mL/min without affecting the ionization conditions of the mass spectrometer. A new way of packing large amounts of graphitized carbon allowed the enrichment and separation of milligram quantities of structurally heterogeneous mixtures of human milk oligosaccharides (HMOs) and bovine milk oligosaccharides (BMOs). Abundant saccharide components in milk, such as lactose and lacto-N-tetraose, were separated from the rarer and less abundant oligosaccharides that have greater structural diversity and biological functionality. Neutral and acidic HMOs and BMOs were largely separated and enriched with a dual binary solvent system. PMID:22370281

Enhanced CO2 capture in binary mixtures of 1-alkyl-3-methylimidazolium tricyanomethanide ionic liquids with water.

PubMed

Romanos, George E; Zubeir, Lawien F; Likodimos, Vlassis; Falaras, Polycarpos; Kroon, Maaike C; Iliev, Boyan; Adamova, Gabriela; Schubert, Thomas J S

2013-10-10

Absorption of carbon dioxide and water in 1-butyl-3-methylimidazoliun tricyanomethanide ([C4C1im][TCM]) and 1-octyl-3-methylimidazolium tricyanomethanide ([C8C1im][TCM]) ionic liquids (ILs) was systematically investigated for the first time as a function of the H2O content by means of a gravimetric system together with in-situ Raman spectroscopy, excess molar volume (V(E)), and viscosity deviation measurements. Although CO2 absorption was marginally affected by water at low H2O molar fractions for both ILs, an increase of the H2O content resulted in a marked enhancement of both the CO2 solubility (ca. 4-fold) and diffusivity (ca. 10-fold) in the binary [C(n)C1im][TCM]/H2O systems, in contrast to the weak and/or detrimental influence of water in most physically and chemically CO2-absorbing ILs. In-situ Raman spectroscopy on the IL/CO2 systems verified that CO2 is physically absorbed in the dry ILs with no significant effect on their structural organization. A pronounced variation of distinct tricyanomethanide Raman modes was disclosed in the [C(n)C1im][TCM]/H2O mixtures, attesting to the gradual disruption of the anion-cation coupling by the hydrogen-bonded water molecules to the [TCM](-) anions, in accordance with the positive excess molar volumes and negative viscosity deviations for the binary systems. Most importantly, CO2 absorption in the ILs/H2O mixtures at high water concentrations revealed that the [TCM](-) Raman modes tend to restore their original state for the heavily hydrated ILs, in qualitative agreement with the intriguing nonmonotonous transients of CO2 absorption kinetics unveiled by the gravimetric measurements for the hybrid solvents. A molecular exchange mechanism between CO2 in the gas phase and H2O in the liquid phase was thereby proposed to explain the enhanced CO2 absorption in the hybrid [C(n)C1im][TCM]//H2O solvents based on the subtle competition between the TCM-H2O and TCM-CO2 interactions, which renders these ILs very promising for CO2 separation applications.

On The Validity of the Assumed PDF Method for Modeling Binary Mixing/Reaction of Evaporated Vapor in GAS/Liquid-Droplet Turbulent Shear Flow

NASA Technical Reports Server (NTRS)

Miller, R. S.; Bellan, J.

1997-01-01

An Investigation of the statistical description of binary mixing and/or reaction between a carrier gas and an evaporated vapor species in two-phase gas-liquid turbulent flows is perfomed through both theroetical analysis and comparisons with results from direct numerical simulations (DNS) of a two-phase mixing layer.

Molecular dynamics simulation for the test of calibrated OPLS-AA force field for binary liquid mixture of tri-iso-amyl phosphate and n-dodecane.

PubMed

Das, Arya; Ali, Sk Musharaf

2018-02-21

Tri-isoamyl phosphate (TiAP) has been proposed to be an alternative for tri-butyl phosphate (TBP) in the Plutonium Uranium Extraction (PUREX) process. Recently, we have successfully calibrated and tested all-atom optimized potentials for liquid simulations using Mulliken partial charges for pure TiAP, TBP, and dodecane by performing molecular dynamics (MD) simulation. It is of immense importance to extend this potential for the various molecular properties of TiAP and TiAP/n-dodecane binary mixtures using MD simulation. Earlier, efforts were devoted to find out a suitable force field which can explain both structural and dynamical properties by empirical parameterization. Therefore, the present MD study reports the structural, dynamical, and thermodynamical properties with different mole fractions of TiAP-dodecane mixtures at the entire range of mole fraction of 0-1 employing our calibrated Mulliken embedded optimized potentials for liquid simulation (OPLS) force field. The calculated electric dipole moment of TiAP was seen to be almost unaffected by the TiAP concentration in the dodecane diluent. The calculated liquid densities of the TiAP-dodecane mixture are in good agreement with the experimental data. The mixture densities at different temperatures are also studied which was found to be reduced with temperature as expected. The plot of diffusivities for TiAP and dodecane against mole fraction in the binary mixture intersects at a composition in the range of 25%-30% of TiAP in dodecane, which is very much closer to the TBP/n-dodecane composition used in the PUREX process. The excess volume of mixing was found to be positive for the entire range of mole fraction and the excess enthalpy of mixing was shown to be endothermic for the TBP/n-dodecane mixture as well as TiAP/n-dodecane mixture as reported experimentally. The spatial pair correlation functions are evaluated between TiAP-TiAP and TiAP-dodecane molecules. Further, shear viscosity has been computed by performing the non-equilibrium molecular dynamics employing the periodic perturbation method. The calculated shear viscosity of the binary mixture is found to be in excellent agreement with the experimental values. The use of the newly calibrated OPLS force field embedding Mulliken charges is shown to be equally reliable in predicting the structural and dynamical properties for the mixture without incorporating any arbitrary scaling in the force field or Lennard-Jones parameters. Further, the present MD simulation results demonstrate that the Stokes-Einstein relation breaks down at the molecular level. The present methodology might be adopted to evaluate the liquid state properties of an aqueous-organic biphasic system, which is of great significance in the interfacial science and technology.

Molecular dynamics simulation for the test of calibrated OPLS-AA force field for binary liquid mixture of tri-iso-amyl phosphate and n-dodecane

NASA Astrophysics Data System (ADS)

Das, Arya; Ali, Sk. Musharaf

2018-02-01

Tri-isoamyl phosphate (TiAP) has been proposed to be an alternative for tri-butyl phosphate (TBP) in the Plutonium Uranium Extraction (PUREX) process. Recently, we have successfully calibrated and tested all-atom optimized potentials for liquid simulations using Mulliken partial charges for pure TiAP, TBP, and dodecane by performing molecular dynamics (MD) simulation. It is of immense importance to extend this potential for the various molecular properties of TiAP and TiAP/n-dodecane binary mixtures using MD simulation. Earlier, efforts were devoted to find out a suitable force field which can explain both structural and dynamical properties by empirical parameterization. Therefore, the present MD study reports the structural, dynamical, and thermodynamical properties with different mole fractions of TiAP-dodecane mixtures at the entire range of mole fraction of 0-1 employing our calibrated Mulliken embedded optimized potentials for liquid simulation (OPLS) force field. The calculated electric dipole moment of TiAP was seen to be almost unaffected by the TiAP concentration in the dodecane diluent. The calculated liquid densities of the TiAP-dodecane mixture are in good agreement with the experimental data. The mixture densities at different temperatures are also studied which was found to be reduced with temperature as expected. The plot of diffusivities for TiAP and dodecane against mole fraction in the binary mixture intersects at a composition in the range of 25%-30% of TiAP in dodecane, which is very much closer to the TBP/n-dodecane composition used in the PUREX process. The excess volume of mixing was found to be positive for the entire range of mole fraction and the excess enthalpy of mixing was shown to be endothermic for the TBP/n-dodecane mixture as well as TiAP/n-dodecane mixture as reported experimentally. The spatial pair correlation functions are evaluated between TiAP-TiAP and TiAP-dodecane molecules. Further, shear viscosity has been computed by performing the non-equilibrium molecular dynamics employing the periodic perturbation method. The calculated shear viscosity of the binary mixture is found to be in excellent agreement with the experimental values. The use of the newly calibrated OPLS force field embedding Mulliken charges is shown to be equally reliable in predicting the structural and dynamical properties for the mixture without incorporating any arbitrary scaling in the force field or Lennard-Jones parameters. Further, the present MD simulation results demonstrate that the Stokes-Einstein relation breaks down at the molecular level. The present methodology might be adopted to evaluate the liquid state properties of an aqueous-organic biphasic system, which is of great significance in the interfacial science and technology.

Proteomic analysis of a model fish species exposed to individual pesticides and a binary mixture

EPA Science Inventory

Aquatic organisms are often exposed to multiple pesticides simultaneously. Due to the relatively poor characterization of mixture constituent interactions and the potential for highly complex exposure scenarios, there is considerable uncertainty in understanding the toxicity of m...

Boiling Temperature vs. Composition. An Almost-Exact Explicit Equation for a Binary Mixture Following Raoult's Law.

ERIC Educational Resources Information Center

Cardinali, Mario Emilio; Giomini, Claudio

1989-01-01

Proposes a simple procedure based on an expansion of the exponential terms of Raoult's law by applying it to the case of the benzene-toluene mixture. The results with experimental values are presented as a table. (YP)

Separation of non-racemic mixtures of enantiomers: an essential part of optical resolution.

PubMed

Faigl, Ferenc; Fogassy, Elemér; Nógrádi, Mihály; Pálovics, Emese; Schindler, József

2010-03-07

Non-racemic enantiomeric mixtures form homochiral and heterochiral aggregates in melt or suspension, during adsorption or recrystallization, and these diastereomeric associations determine the distribution of the enantiomers between the solid and other (liquid or vapour) phases. That distribution depends on the stability order of the homo- and heterochiral aggregates (conglomerate or racemate formation). Therefore, there is a correlation between the binary melting point phase diagrams and the experimental ee(I)vs. ee(0) curves (ee(I) refers to the crystallized enantiomeric mixtures, ee(0) is the composition of the starting ones). Accordingly, distribution of the enantiomeric mixtures between two phases is characteristic and usually significant enrichment can be achieved. There are two exceptions: no enrichment could be observed under thermodynamically controlled conditions when the starting enantiomer composition corresponded to the eutectic composition, or when the method used was unsuitable for separation. In several cases, when kinetic control governed the crystallization, the character of the ee(0)-ee(I) curve did not correlate with the melting point binary phase diagram.

Can an ammonium-based room temperature ionic liquid counteract the urea-induced denaturation of a small peptide?

PubMed

Ghosh, Soumadwip; Dey, Souvik; Patel, Mahendra; Chakrabarti, Rajarshi

2017-03-15

The folding/unfolding equilibrium of proteins in aqueous medium can be altered by adding small organic molecules generally termed as co-solvents. Denaturants such as urea are instrumental in the unfolding of proteins while protecting osmolytes favour the folded ensemble. Recently, room temperature ionic liquids (ILs) have been shown to counteract the deleterious effect of urea on proteins. In this paper, using atomistic molecular dynamics we show that a ternary mixture containing a particular ammonium-based IL, triethylammonium acetate (TEAA), and urea (in 1 : 5 molar ratio) helps a small 15-residue S-peptide analogue regain most of its native structure, whereas a binary aqueous mixture containing a large amount of urea alone completely distorts it. Our simulations show that the denaturant urea directly interacts with the peptide backbone in the binary mixture while for the ternary mixture both urea as well as the IL are preferentially excluded from the peptide surface.

Electro-olfactogram and multiunit olfactory receptor responses to binary and trinary mixtures of amino acids in the channel catfish, Ictalurus punctatus

PubMed Central

1989-01-01

In vivo electrophysiological recordings from populations of olfactory receptor neurons in the channel catfish, Ictalurus punctatus, clearly showed that responses to binary and trinary mixtures of amino acids were predictable with knowledge obtained from previous cross-adaptation studies of the relative independence of the respective binding sites of the component stimuli. All component stimuli, from which equal aliquots were drawn to form the mixtures, were adjusted in concentration to provide for approximately equal response magnitudes. The magnitude of the response to a mixture whose component amino acids showed significant cross-reactivity was equivalent to the response to any single component used to form that mixture. A mixture whose component amino acids showed minimal cross-adaptation produced a significantly larger relative response than a mixture whose components exhibited considerable cross-reactivity. This larger response approached the sum of the responses to the individual component amino acids tested at the resulting concentrations in the mixture, even though olfactory receptor dose-response functions for amino acids in this species are characterized by extreme sensory compression (i.e., successive concentration increments produce progressively smaller physiological responses). Thus, the present study indicates that the response to sensory stimulation of olfactory receptor sites is more enhanced by the activation of different receptor site types than by stimulus interaction at a single site type. PMID:2703818

30 CFR 36.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... through it. Flammable mixture. A mixture of gas, such as methane, natural gas, or similar hydrocarbon gas... constructed and protected by an enclosure and/or flame arrester (s) that if a flammable mixture of gas is... is: (1) Used for transporting the product being mined or excavated, or for transporting materials and...

30 CFR 36.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... through it. Flammable mixture. A mixture of gas, such as methane, natural gas, or similar hydrocarbon gas... constructed and protected by an enclosure and/or flame arrester (s) that if a flammable mixture of gas is... is: (1) Used for transporting the product being mined or excavated, or for transporting materials and...

30 CFR 36.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through it. Flammable mixture. A mixture of gas, such as methane, natural gas, or similar hydrocarbon gas... constructed and protected by an enclosure and/or flame arrester (s) that if a flammable mixture of gas is... is: (1) Used for transporting the product being mined or excavated, or for transporting materials and...

30 CFR 36.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through it. Flammable mixture. A mixture of gas, such as methane, natural gas, or similar hydrocarbon gas... constructed and protected by an enclosure and/or flame arrester (s) that if a flammable mixture of gas is... is: (1) Used for transporting the product being mined or excavated, or for transporting materials and...

Wire chamber

DOEpatents

Atac, Muzaffer

1989-01-01

A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor.

Nonlinear Least-Squares Based Method for Identifying and Quantifying Single and Mixed Contaminants in Air with an Electronic Nose

PubMed Central

Zhou, Hanying; Homer, Margie L.; Shevade, Abhijit V.; Ryan, Margaret A.

2006-01-01

The Jet Propulsion Laboratory has recently developed and built an electronic nose (ENose) using a polymer-carbon composite sensing array. This ENose is designed to be used for air quality monitoring in an enclosed space, and is designed to detect, identify and quantify common contaminants at concentrations in the parts-per-million range. Its capabilities were demonstrated in an experiment aboard the National Aeronautics and Space Administration's Space Shuttle Flight STS-95. This paper describes a modified nonlinear least-squares based algorithm developed to analyze data taken by the ENose, and its performance for the identification and quantification of single gases and binary mixtures of twelve target analytes in clean air. Results from laboratory-controlled events demonstrate the effectiveness of the algorithm to identify and quantify a gas event if concentration exceeds the ENose detection threshold. Results from the flight test demonstrate that the algorithm correctly identifies and quantifies all registered events (planned or unplanned, as singles or mixtures) with no false positives and no inconsistencies with the logged events and the independent analysis of air samples.

Thermodiffusion Coefficient Analysis of n-Dodecane /n-Hexane Mixture at Different Mass Fractions and Pressure Conditions

NASA Astrophysics Data System (ADS)

Lizarraga, Ion; Bou-Ali, M. Mounir; Santamaría, C.

2018-03-01

In this study, the thermodiffusion coefficient of n-dodecane/n-hexane binary mixture at 25 ∘C mean temperature was determined for several pressure conditions and mass fractions. The experimental technique used to determine the thermodiffusion coefficient was the thermograviational column of cylindrical configuration. In turn, thermophysical properties, such as density, thermal expansion, mass expansion and dynamic viscosity up to 10 MPa were also determined. The results obtained in this work showed a linear relation between the thermophysical properties and the pressure. Thermodiffusion coefficient values confirm a linear effect when the pressure increases. Additionally, a new correlation based on the thermodiffusion coefficient for n C12/n C6 binary mixture at 25 ∘C temperature for any mass fraction and pressures, which reproduces the data within the experimental error, was proposed.

Detection of melamine in milk powders using near-infrared hyperspectral imaging combined with regression coefficient of partial least square regression model.

PubMed

Lim, Jongguk; Kim, Giyoung; Mo, Changyeun; Kim, Moon S; Chao, Kuanglin; Qin, Jianwei; Fu, Xiaping; Baek, Insuck; Cho, Byoung-Kwan

2016-05-01

Illegal use of nitrogen-rich melamine (C3H6N6) to boost perceived protein content of food products such as milk, infant formula, frozen yogurt, pet food, biscuits, and coffee drinks has caused serious food safety problems. Conventional methods to detect melamine in foods, such as Enzyme-linked immunosorbent assay (ELISA), High-performance liquid chromatography (HPLC), and Gas chromatography-mass spectrometry (GC-MS), are sensitive but they are time-consuming, expensive, and labor-intensive. In this research, near-infrared (NIR) hyperspectral imaging technique combined with regression coefficient of partial least squares regression (PLSR) model was used to detect melamine particles in milk powders easily and quickly. NIR hyperspectral reflectance imaging data in the spectral range of 990-1700nm were acquired from melamine-milk powder mixture samples prepared at various concentrations ranging from 0.02% to 1%. PLSR models were developed to correlate the spectral data (independent variables) with melamine concentration (dependent variables) in melamine-milk powder mixture samples. PLSR models applying various pretreatment methods were used to reconstruct the two-dimensional PLS images. PLS images were converted to the binary images to detect the suspected melamine pixels in milk powder. As the melamine concentration was increased, the numbers of suspected melamine pixels of binary images were also increased. These results suggested that NIR hyperspectral imaging technique and the PLSR model can be regarded as an effective tool to detect melamine particles in milk powders. Copyright © 2016 Elsevier B.V. All rights reserved.

The nonlinear model for emergence of stable conditions in gas mixture in force field

NASA Astrophysics Data System (ADS)

Kalutskov, Oleg; Uvarova, Liudmila

2016-06-01

The case of M-component liquid evaporation from the straight cylindrical capillary into N - component gas mixture in presence of external forces was reviewed. It is assumed that the gas mixture is not ideal. The stable states in gas phase can be formed during the evaporation process for the certain model parameter valuesbecause of the mass transfer initial equationsnonlinearity. The critical concentrations of the resulting gas mixture components (the critical component concentrations at which the stable states occur in mixture) were determined mathematically for the case of single-component fluid evaporation into two-component atmosphere. It was concluded that this equilibrium concentration ratio of the mixture components can be achieved by external force influence on the mass transfer processes. It is one of the ways to create sustainable gas clusters that can be used effectively in modern nanotechnology.

Simulation of granular and gas-solid flows using discrete element method

NASA Astrophysics Data System (ADS)

Boyalakuntla, Dhanunjay S.

2003-10-01

In recent years there has been increased research activity in the experimental and numerical study of gas-solid flows. Flows of this type have numerous applications in the energy, pharmaceuticals, and chemicals process industries. Typical applications include pulverized coal combustion, flow and heat transfer in bubbling and circulating fluidized beds, hopper and chute flows, pneumatic transport of pharmaceutical powders and pellets, and many more. The present work addresses the study of gas-solid flows using computational fluid dynamics (CFD) techniques and discrete element simulation methods (DES) combined. Many previous studies of coupled gas-solid flows have been performed assuming the solid phase as a continuum with averaged properties and treating the gas-solid flow as constituting of interpenetrating continua. Instead, in the present work, the gas phase flow is simulated using continuum theory and the solid phase flow is simulated using DES. DES treats each solid particle individually, thus accounting for its dynamics due to particle-particle interactions, particle-wall interactions as well as fluid drag and buoyancy. The present work involves developing efficient DES methods for dense granular flow and coupling this simulation to continuum simulations of the gas phase flow. Simulations have been performed to observe pure granular behavior in vibrating beds. Benchmark cases have been simulated and the results obtained match the published literature. The dimensionless acceleration amplitude and the bed height are the parameters governing bed behavior. Various interesting behaviors such as heaping, round and cusp surface standing waves, as well as kinks, have been observed for different values of the acceleration amplitude for a given bed height. Furthermore, binary granular mixtures (granular mixtures with two particle sizes) in a vibrated bed have also been studied. Gas-solid flow simulations have been performed to study fluidized beds. Benchmark 2D fluidized bed simulations have been performed and the results have been shown to satisfactorily compare with those published in the literature. A comprehensive study of the effect of drag correlations on the simulation of fluidized beds has been performed. It has been found that nearly all the drag correlations studied make similar predictions of global quantities such as the time-dependent pressure drop, bubbling frequency and growth. In conclusion, discrete element simulation has been successfully coupled to continuum gas-phase. Though all the results presented in the thesis are two-dimensional, the present implementation is completely three dimensional and can be used to study 3D fluidized beds to aid in better design and understanding. Other industrially important phenomena like particle coating, coal gasification etc., and applications in emerging areas such as nano-particle/fluid mixtures can also be studied through this type of simulation. (Abstract shortened by UMI.)

APPLICATION OF GAS DYNAMICAL FRICTION FOR PLANETESIMALS. II. EVOLUTION OF BINARY PLANETESIMALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grishin, Evgeni; Perets, Hagai B.

2016-04-01

One of the first stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs long before the dispersal of most of the gas from the protoplanetary disk. At this stage gas–planetesimal interactions play a key role in the dynamical evolution of single intermediate-mass planetesimals (m{sub p} ∼ 10{sup 21}–10{sup 25} g) through gas dynamical friction (GDF). A significant fraction of all solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of BPs embedded inmore » a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above m{sub p} ≳ 10{sup 22} g at 1 au, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of merger-formed planetesimals, and the GDF-induced binary inspiral can play a role in the evolution of the planetesimal disk. In addition, binaries on eccentric orbits around the star may evolve in the supersonic regime, where the torque reverses and the binary expands, which would enhance the cross section for planetesimal encounters with the binary. Highly inclined binaries with small mass ratios, evolve due to the combined effects of Kozai–Lidov (KL) cycles with GDF which lead to chaotic evolution. Prograde binaries go through semi-regular KL evolution, while retrograde binaries frequently flip their inclination and ∼50% of them are destroyed.« less

Phase equilibrium measurements on twelve binary mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giles, N.F.; Wilson, H.L.; Wilding, W.V.

1996-11-01

Phase equilibrium measurements have been performed on twelve binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following binary systems at two temperatures each: ethanethiol + propylene; nitrobenzene + methanol; pyridine + ethyl acetate; octane + tert-amyl methyl ether; diisopropyl ether + butane; 1,3-dichloro-2-propanol + epichlorohydrin; 2,3-dichloro-1-propanol + epichlorohydrin; 2,3-epoxy-1-propanol + epichlorohydrin; 3-chloro-1,2-propanediol + epichlorohydrin; methanol + hydrogen cyanide. For these systems, equilibrium vapor and liquid phase compositions were derived from the PTx data using the Soave equation of state to represent the vapor phase and the Wilson, NRTL, or Redlich-Kister activity coefficient model tomore » represent the liquid phase. The infinite dilution activity coefficient of methylamine in N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone-rich half of the binary. Liquid-liquid equilibrium studies were made on the triethylene glycol + 1-pentene system at two temperatures by directly analyzing samples taken from each liquid phase.« less

Refractive index and solubility control of para-cymene solutions for index-matched fluid-structure interaction studies

NASA Astrophysics Data System (ADS)

Fort, Charles; Fu, Christopher D.; Weichselbaum, Noah A.; Bardet, Philippe M.

2015-12-01

To deploy optical diagnostics such as particle image velocimetry or planar laser-induced fluorescence (PLIF) in complex geometries, it is beneficial to use index-matched facilities. A binary mixture of para-cymene and cinnamaldehyde provides a viable option for matching the refractive index of acrylic, a common material for scaled models and test sections. This fluid is particularly appropriate for large-scale facilities and when a low-density and low-viscosity fluid is sought, such as in fluid-structure interaction studies. This binary solution has relatively low kinematic viscosity and density; its use enables the experimentalist to select operating temperature and to increase fluorescence signal in PLIF experiments. Measurements of spectral and temperature dependence of refractive index, density, and kinematic viscosity are reported. The effect of the binary mixture on solubility control of Rhodamine 6G is also characterized.

Utilisation of the isobole methodology to study dietary peptide-drug and peptide-peptide interactive effects on dipeptidyl peptidase IV (DPP-IV) inhibition.

PubMed

Nongonierma, Alice B; FitzGerald, Richard J

2015-01-01

Inhibition of dipeptidyl peptidase-IV (DPP-IV) is used as a means to regulate post-prandial serum glucose in type 2 diabetics. The effect of drug (Sitagliptin®)/peptide and binary peptide mixtures on DPP-IV inhibition was studied using an isobole approach. Five peptides (Ile-Pro-Ile-Gln-Tyr, Trp-Lys, Trp-Pro, Trp-Arg and Trp-Leu), having DPP-IV half maximum inhibitory concentration values (IC₅₀)<60 μM and reported to act through different inhibition mechanisms, were investigated. The dose response relationship of Sitagliptin : peptide (1:0, 0:1, 1:852, 1:426 and 1:1704 on a molar basis) and binary Ile-Pro-Ile-Gln-Tyr : peptide (1:0, 0:1, 1:1, 1:2 and 2:1 on a molar basis) mixtures for DPP-IV inhibition was characterised. Isobolographic analysis showed, in most instances, an additive effect on DPP-IV inhibition. However, a synergistic effect was observed with two Sitagliptin:Ile-Pro-Ile-Gln-Tyr (1:426 and 1:852) mixtures and an antagonistic effect was seen with one Sitagliptin : Trp-Pro (1:852) mixture, and three binary peptide mixtures (Ile-Pro-Ile-Gln-Tyr : Trp-Lys (1:1 and 2:1) and Ile-Pro-Ile-Gln-Tyr:Trp-Leu (1:2)). The results show that Sitagliptin and food protein-derived peptides can interact, thereby enhancing overall DPP-IV inhibition. Combination of Sitagliptin with food protein-derived peptides may help in reducing drug dosage and possible associated side-effects.

An evaluation of three-dimensional modeling of compaction cycles by analyzing the densification behavior of binary and ternary mixtures.

PubMed

Picker, K M; Bikane, F

2001-08-01

The aim of the study is to use the 3D modeling technique of compaction cycles for analysis of binary and ternary mixtures. Three materials with very different deformation and densification characteristics [cellulose acetate (CAC), dicalcium phosphate dihydrate (EM) and theophylline monohydrate (TM)] have been tableted at graded maximum relative densities (rhorel, max) on an eccentric tableting machine. Following that, graded binary mixtures from CAC and EM have been compacted. Finally, the same ratios of CAC and EM have been tableted in a ternary mixture with 20 vol% TM. All compaction cycles have been analyzed by using different data analysis methods. Three-dimensional modeling, conventional determination of the slope of the Heckel function, determination of the elastic recovery during decompression, and calculations according to the pressure-time function were the methods of choice. The results show that the 3D model technique is able to gain the information in one step instead of three different approaches, which is an advantage for formulation development. The results show that this model enables one to better distinguish the compaction properties of mixtures and the interaction of the components in the tablet than 2D models. Furthermore, the information by 3D modeling is more precise since in the slope K of the Heckel-plot (in die) elasticity is included, and in the parameters of the pressure-time function beta and gamma plastic deformation due to pressure is included. The influence of time and pressure on the displacement can now be differentiated.

Evaluation of alfalfa-tall fescue mixtures across multiple environments

USDA-ARS?s Scientific Manuscript database

Binary grass-legume mixtures can benefit forage production systems in different ways helping growers cope both with increasing input costs (e.g., N fertilizer, herbicides) and potentially more variable weather. The main objective of this study was to evaluate alfalfa (Medicago sativa L.) and tall f...

Metal/ceramic composites with high hydrogen permeability

DOEpatents

Dorris, Stephen E.; Lee, Tae H.; Balachandran, Uthamalingam

2003-05-27

A membrane for separating hydrogen from fluids is provided comprising a sintered homogenous mixture of a ceramic composition and a metal. The metal may be palladium, niobium, tantalum, vanadium, or zirconium or a binary mixture of palladium with another metal such as niobium, silver, tantalum, vanadium, or zirconium.

Binary mixtures of condensates in generic confining potentials

NASA Astrophysics Data System (ADS)

Facchi, P.; Florio, G.; Pascazio, S.; Pepe, F. V.

2011-12-01

We study a binary mixture of Bose-Einstein condensates, confined in a generic potential, in the Thomas-Fermi approximation. We search for the zero-temperature ground state of the system, both in the case of fixed numbers of particles and fixed chemical potentials. For generic potentials, we analyze the transition from mixed to separated ground-state configurations as the inter-species interaction increases. We derive a simple formula that enables one to determine the location of the domain walls. Finally, we find criteria for the energetic stability of separated configurations, depending on the number and the position of the domain walls separating the two species.

Sol-gel type synthesis of Bi.sub.2 (Sr,Ta.sub.2)O.sub.9 using an acetate based system

DOEpatents

Boyle, Timothy J.

1997-01-01

A method of forming a layered-perovskite bismuth-strontium-tantalum oxide (SBT) ferroelectric material is performed by dissolving a bismuth compound in a first solvent to form a first solution, mixing a strontium compound and a tantalum compound to form a binary mixture, dissolving the binary mixture in a second solvent to form a second solution, mixing the first solution with the second solution to form a SBT precursor solution, evaporating the first and second solvents to form a SBT precursor material and subsequently sintering said SBT precursor material in the presence of oxygen.

Sol-gel type synthesis of Bi{sub 2}(Sr,Ta{sub 2})O{sub 9} using an acetate based system

DOEpatents

Boyle, T.J.

1997-11-04

A method of forming a layered-perovskite bismuth-strontium-tantalum oxide (SBT) ferroelectric material is performed by dissolving a bismuth compound in a first solvent to form a first solution, mixing a strontium compound and a tantalum compound to form a binary mixture, dissolving the binary mixture in a second solvent to form a second solution, mixing the first solution with the second solution to form a SBT precursor solution, evaporating the first and second solvents to form a SBT precursor material and subsequently sintering said SBT precursor material in the presence of oxygen. 6 figs.

Transport properties of nonelectrolyte liquid mixtures—VI. Viscosimetric study of binary mixtures of hexafluorobenzene with aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Dymond, J. H.; Robertson, J.

1985-01-01

Viscosity coefficients for binary mixtures of hexafluorobenzene with benzene, toluene, para-xylene, and mesitylene have been measured along the saturation line at temperatures from 15 to 120°C using specially designed capillary viscometers. Densities were measured using a pyknometer and volume-change apparatus. Deviations of the viscosities from a rectilinear dependence on mole fraction are consistent with enhanced interactions between unlike species, which increase with increasing number of methyl groups on the aromatic hydrocarbon and decrease with increasing temperature. The application of the Grunberg and Nissan equation, the Hildebrand equation, and energy of activation theories to these results is examined.

Formation of an amorphous phase and its crystallization in the immiscible Nb-Zr system by mechanical alloying

NASA Astrophysics Data System (ADS)

Al-Aqeeli, N.; Suryanarayana, C.; Hussein, M. A.

2013-10-01

Mechanical alloying of binary Nb-Zr powder mixtures was carried out to evaluate the formation of metastable phases in this immiscible system. The milled powders were characterized for their constitution and structure by X-ray diffraction and transmission electron microscopy methods. It was shown that an amorphous phase had formed on milling the binary powder mixture for about 10 h and that it had crystallized on subsequent milling up to 50-70 h, referred to as mechanical crystallization. Thermodynamic and structural arguments have been presented to explain the formation of the amorphous phase and its subsequent crystallization.

The susceptibility critical exponent for a nonaqueous ionic binary mixture near a consolute point

NASA Technical Reports Server (NTRS)

Zhang, Kai C.; Briggs, Matthew E.; Gammon, Robert W.; Levelt Sengers, J. M. H.

1992-01-01

We report turbidity measurements of a nonaqueous ionic solution of triethyl n-hexylammonium triethyl n-hexylboride in diphenyl ether. A classical susceptibility critical exponent gamma = 1.01 +/- 0.01 is obtained over the reduced temperature range t between values of 0.1 and 0.0001. The best fits of the sample transmission had a standard deviation of 0.39 percent over this range. Ising and spherical model critical exponents are firmly excluded. The correlation length amplitude xi sub 0 from fitting is 1.0 +/- 0.2 nm which is much larger than values found in neutral fluids and some aqueous binary mixtures.

Quantitative analysis of binary polymorphs mixtures of fusidic acid by diffuse reflectance FTIR spectroscopy, diffuse reflectance FT-NIR spectroscopy, Raman spectroscopy and multivariate calibration.

PubMed

Guo, Canyong; Luo, Xuefang; Zhou, Xiaohua; Shi, Beijia; Wang, Juanjuan; Zhao, Jinqi; Zhang, Xiaoxia

2017-06-05

Vibrational spectroscopic techniques such as infrared, near-infrared and Raman spectroscopy have become popular in detecting and quantifying polymorphism of pharmaceutics since they are fast and non-destructive. This study assessed the ability of three vibrational spectroscopy combined with multivariate analysis to quantify a low-content undesired polymorph within a binary polymorphic mixture. Partial least squares (PLS) regression and support vector machine (SVM) regression were employed to build quantitative models. Fusidic acid, a steroidal antibiotic, was used as the model compound. It was found that PLS regression performed slightly better than SVM regression in all the three spectroscopic techniques. Root mean square errors of prediction (RMSEP) were ranging from 0.48% to 1.17% for diffuse reflectance FTIR spectroscopy and 1.60-1.93% for diffuse reflectance FT-NIR spectroscopy and 1.62-2.31% for Raman spectroscopy. The results indicate that diffuse reflectance FTIR spectroscopy offers significant advantages in providing accurate measurement of polymorphic content in the fusidic acid binary mixtures, while Raman spectroscopy is the least accurate technique for quantitative analysis of polymorphs. Copyright © 2017 Elsevier B.V. All rights reserved.

UV-Vis spectroscopic study and DFT calculation on the solvent effect of trimethoprim in neat solvents and aqueous mixtures.

PubMed

Almandoz, M C; Sancho, M I; Duchowicz, P R; Blanco, S E

2014-08-14

The solvatochromic behavior of trimethoprim (TMP) was analyzed using UV-Vis spectroscopy and DFT methods in neat and binary aqueous solvent mixtures. The effects of solvent dipolarity/polarizability and solvent-solute hydrogen bonding interactions on the absorption maxima were evaluated by means of the linear solvation energy relationship concept of Kamlet and Taft. This analysis indicated that both interactions play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra of TMP and TMP:(solvent)n complexes in ACN and H2O using TD-DFT methods were in agreement with the experimental ones. Binary aqueous mixtures containing as co-solvents DMSO, ACN and EtOH were studied. Preferential solvation was detected as a nonideal behavior of the wavenumber curve respective to the analytical mole fraction of co-solvent in all binary systems. TMP molecules were preferentially solvated by the organic solvent over the whole composition range. Index of preferential solvation, as well as the influence of solvent parameters were calculated as a function of solvent composition. Copyright © 2014 Elsevier B.V. All rights reserved.

Inferential determination of various properties of a gas mixture

DOEpatents

Morrow, Thomas B.; Behring, II, Kendricks A.

2007-03-27

Methods for inferentially determining various properties of a gas mixture, when the speed of sound in the gas is known at an arbitrary temperature and pressure. The method can be applied to natural gas mixtures, where the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for heating value calculations. The method may also be applied to inferentially determine density and molecular weight for gas mixtures other than natural gases.

Leakiness of Pinned Neighboring Surface Nanobubbles Induced by Strong Gas–Surface Interaction

PubMed Central

2018-01-01

The stability of two neighboring surface nanobubbles on a chemically heterogeneous surface is studied by molecular dynamics (MD) simulations of binary mixtures consisting of Lennard-Jones (LJ) particles. A diffusion equation-based stability analysis suggests that two nanobubbles sitting next to each other remain stable, provided the contact line is pinned, and that their radii of curvature are equal. However, many experimental observations seem to suggest some long-term kind of ripening or shrinking of the surface nanobubbles. In our MD simulations we find that the growth/dissolution of the nanobubbles can occur due to the transfer of gas particles from one nanobubble to another along the solid substrate. That is, if the interaction between the gas and the solid is strong enough, the solid–liquid interface can allow for the existence of a “tunnel” which connects the liquid–gas interfaces of the two nanobubbles to destabilize the system. The crucial role of the gas–solid interaction energy is a nanoscopic element that hitherto has not been considered in any macroscopic theory of surface nanobubbles and may help to explain experimental observations of the long-term ripening. PMID:29438620

Hydrogen leak detection using laser-induced breakdown spectroscopy.

PubMed

Ball, A J; Hohreiter, V; Hahn, D W

2005-03-01

Laser-induced breakdown spectroscopy (LIBS) is investigated as a technique for real-time monitoring of hydrogen gas. Two methodologies were examined: The use of a 100 mJ laser pulse to create a laser-induced breakdown directly in a sample gas stream, and the use of a 55 mJ laser pulse to create a laser-induced plasma on a solid substrate surface, with the expanding plasma sampling the gas stream. Various metals were analyzed as candidate substrate surfaces, including aluminum, copper, molybdenum, stainless steel, titanium, and tungsten. Stainless steel was selected, and a detailed analysis of hydrogen detection in binary mixtures of nitrogen and hydrogen at atmospheric pressure was performed. Both the gaseous plasma and the plasma initiated on the stainless steel surface generated comparable hydrogen emission signals, using the 656.28 Halpha emission line, and exhibited excellent signal linearity. The limit of detection is about 20 ppm (mass) as determined for both methodologies, with the solid-initiated plasma yielding a slightly better value. Overall, LIBS is concluded to be a viable candidate for hydrogen sensing, offering a combination of high sensitivity with a technique that is well suited to implementation in field environments.

Mixture optimization for mixed gas Joule-Thomson cycle

NASA Astrophysics Data System (ADS)

Detlor, J.; Pfotenhauer, J.; Nellis, G.

2017-12-01

An appropriate gas mixture can provide lower temperatures and higher cooling power when used in a Joule-Thomson (JT) cycle than is possible with a pure fluid. However, selecting gas mixtures to meet specific cooling loads and cycle parameters is a challenging design problem. This study focuses on the development of a computational tool to optimize gas mixture compositions for specific operating parameters. This study expands on prior research by exploring higher heat rejection temperatures and lower pressure ratios. A mixture optimization model has been developed which determines an optimal three-component mixture based on the analysis of the maximum value of the minimum value of isothermal enthalpy change, ΔhT , that occurs over the temperature range. This allows optimal mixture compositions to be determined for a mixed gas JT system with load temperatures down to 110 K and supply temperatures above room temperature for pressure ratios as small as 3:1. The mixture optimization model has been paired with a separate evaluation of the percent of the heat exchanger that exists in a two-phase range in order to begin the process of selecting a mixture for experimental investigation.

Development of a Physiologically Based Pharmacokinetic and Pharmacodynamic Model to Determine Dosimetry and Cholinesterase Inhibition for a Binary Mixture of Chlorpyrifos and Diazinon in the Rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timchalk, Chuck; Poet, Torka S.

2008-05-01

Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models have been developed and validated for the organophosphorus (OP) insecticides chlorpyrifos (CPF) and diazinon (DZN). Based on similar pharmacokinetic and mode of action properties it is anticipated that these OPs could interact at a number of important metabolic steps including: CYP450 mediated activation/detoxification, and blood/tissue cholinesterase (ChE) binding/inhibition. We developed a binary PBPK/PD model for CPF, DZN and their metabolites based on previously published models for the individual insecticides. The metabolic interactions (CYP450) between CPF and DZN were evaluated in vitro and suggests that CPF is more substantially metabolized to its oxon metabolite than ismore » DZN. These data are consistent with their observed in vivo relative potency (CPF>DZN). Each insecticide inhibited the other’s in vitro metabolism in a concentration-dependent manner. The PBPK model code used to described the metabolism of CPF and DZN was modified to reflect the type of inhibition kinetics (i.e. competitive vs. non-competitive). The binary model was then evaluated against previously published rodent dosimetry and ChE inhibition data for the mixture. The PBPK/PD model simulations of the acute oral exposure to single- (15 mg/kg) vs. binary-mixtures (15+15 mg/kg) of CFP and DZN at this lower dose resulted in no differences in the predicted pharmacokinetics of either the parent OPs or their respective metabolites; whereas, a binary oral dose of CPF+DZN at 60+60 mg/kg did result in observable changes in the DZN pharmacokinetics. Cmax was more reasonably fit by modifying the absorption parameters. It is anticipated that at low environmentally relevant binary doses, most likely to be encountered in occupational or environmental related exposures, that the pharmacokinetics are expected to be linear, and ChE inhibition dose-additive.« less

Separation and Detection of Toxic Gases with a Silicon Micromachined Gas Chromatography System

NASA Technical Reports Server (NTRS)

Kolesar, Edward S.; Reston, Rocky R.

1995-01-01

A miniature gas chromatography (GC) system was designed and fabricated using silicon micromachining and integrated circuit (IC) processing techniques. The silicon micromachined gas chromatography system (SMGCS) is composed of a miniature sample injector that incorporates a 10 microliter sample loop; a 0.9 meter long, rectangular shaped (300 micrometer width and 10 micrometer height) capillary column coated with a 0.2 micrometer thick copper phthalocyanine (CuPc) stationary phase; and a dual detector scheme based upon a CuPc-coated chemiresistor and a commercially available 125 micrometer diameter thermal conductivity detector (TCD) bead. Silicon micromachining was employed to fabricate the interface between the sample injector and the GC column, the column itself, and the dual detector cavity. A novel IC thin-film processing technique was developed to sublime the CuPc stationary phase coating on the column walls that were micromachined in the host silicon wafer substrate and Pyrex (r) cover plate, which were then electrostatically bonded together. The SMGCS can separate binary gas mixtures composed of parts-per-million (ppm) concentrations of ammonia (NH3) and nitrogen dioxide (NO2) when isothermally operated (55-80 degrees C). With a helium carrier gas and nitrogen diluent, a 10 microliter sample volume containing ammonia and nitrogen dioxide injected at 40 psi ((2.8 x 10(exp 5)Pa)) can be separated in less than 30 minutes.

The thermochemical characteristics of solution of phenol and benzoic acid in water-dimethylsulfoxide and water-acetonitrile mixtures

NASA Astrophysics Data System (ADS)

Zakharov, A. G.; Voronova, M. I.; Batov, D. V.; Smirnova, K. V.

2011-03-01

The solution of phenol and benzoic acid in water-dimethylsulfoxide (DMSO) and water-acetonitrile (AN) mixtures was studied. As distinct from benzoic acid, the thermodynamic characteristics of solution of phenol sharply change at concentrations corresponding to a change in the character of cluster formation in water-DMSO and water-AN mixtures. Differences in the solvation of phenol and benzoic acid are explained by different mechanisms of the interaction of the solutes with clusters existing in binary mixtures.

Design and fabrication of the Brayton rotating unit

NASA Technical Reports Server (NTRS)

Davis, J. E.

1972-01-01

The Brayton rotating unit (BRU), operating on a gas bearing system, has been designed, fabricated, and demonstrated for use in a closed Brayton cycle space power conversion system. The BRU uses a binary mixture of xenon and helium (molecular weight, 83.8) as the cycle working fluid and bearing lubricating medium and was designed to produce from 2.25 to 10.5 kw sub e of 1200 Hz three-phase electrical power. The single-shaft rotating assembly operates at a design speed of 36,000 rpm and comprises a radial single-stage compressor, a four-pole Rice alternator rotor, and a radial inflow turbine. Four units, a dynamic simulator and three component research packages, were supplied to the NASA Lewis Research Center for performance testing and further development.

Penning Ionization Electron Spectroscopy in Glow Discharge: A New Dimension for Gas Chromatography Detectors

NASA Technical Reports Server (NTRS)

Sheverev, V. A.; Khromov, N. A.; Kojiro, D. R.; Fonda, Mark (Technical Monitor)

2002-01-01

Admixtures to helium of 100 ppm and 5 ppm of nitrogen, and 100 ppm and 10 ppm of carbon monoxide were identified and measured in the helium discharge afterglow using an electrical probe placed into the plasma. For nitrogen and carbon monoxide gases, the measured electron energy spectra display distinct characteristic peaks (fingerprints). Location of the peaks on the energy scale is determined by the ionization energies of the analyte molecules. Nitrogen and carbon monoxide fingerprints were also observed in a binary mixture of these gases in helium, and the relative concentration analytes has been predicted. The technically simple and durable method is considered a good candidate for a number of analytical applications, and in particular, in GC and for analytical flight instrumentation.

Gene Expression Responses in Male Fathead Minnows Exposed to Binary Mixtures of an Estrogen and Antiestrogen

EPA Science Inventory

Aquatic organisms are continuously exposed to complex mixtures of chemicals, many of which can interfere with their endocrine system, resulting in impaired reproduction, development or survival, among others. In order to analyze the effects and mechanisms of action of estrogen...

Construction of Lines of Constant Density and Constant Refractive Index for Ternary Liquid Mixtures.

ERIC Educational Resources Information Center

Tasic, Aleksandar Z.; Djordjevic, Bojan D.

1983-01-01

Demonstrates construction of density constant and refractive index constant lines in triangular coordinate system on basis of systematic experimental determinations of density and refractive index for both homogeneous (single-phase) ternary liquid mixtures (of known composition) and the corresponding binary compositions. Background information,…

Quantitative analysis of multi-component gas mixture based on AOTF-NIR spectroscopy

NASA Astrophysics Data System (ADS)

Hao, Huimin; Zhang, Yong; Liu, Junhua

2007-12-01

Near Infrared (NIR) spectroscopy analysis technology has attracted many eyes and has wide application in many domains in recent years because of its remarkable advantages. But the NIR spectrometer can only be used for liquid and solid analysis by now. In this paper, a new quantitative analysis method of gas mixture by using new generation NIR spectrometer is explored. To collect the NIR spectra of gas mixtures, a vacuumable gas cell was designed and assembled to Luminar 5030-731 Acousto-Optic Tunable Filter (AOTF)-NIR spectrometer. Standard gas samples of methane (CH 4), ethane (C IIH 6) and propane (C 3H 8) are diluted with super pure nitrogen via precision volumetric gas flow controllers to obtain gas mixture samples of different concentrations dynamically. The gas mixtures were injected into the gas cell and the spectra of wavelength between 1100nm-2300nm were collected. The feature components extracted from gas mixture spectra by using Partial Least Squares (PLS) were used as the inputs of the Support Vector Regress Machine (SVR) to establish the quantitative analysis model. The effectiveness of the model is tested by the samples of predicting set. The prediction Root Mean Square Error (RMSE) of CH 4, C IIH 6 and C 3H 8 is respectively 1.27%, 0.89%, and 1.20% when the concentrations of component gas are over 0.5%. It shows that the AOTF-NIR spectrometer with gas cell can be used for gas mixture analysis. PLS combining with SVR has a good performance in NIR spectroscopy analysis. This paper provides the bases for extending the application of NIR spectroscopy analysis to gas detection.

Binary Black Hole Mergers from Planet-like Migrations.

PubMed

Gould; Rix

2000-03-20

If supermassive black holes (BHs) are generically present in galaxy centers, and if galaxies are built up through hierarchical merging, BH binaries are at least temporary features of most galactic bulges. Observations suggest, however, that binary BHs are rare, pointing toward a binary lifetime far shorter than the Hubble time. We show that, almost regardless of the detailed mechanism, all stellar dynamical processes are too slow in reducing the orbital separation once orbital velocities in the binary exceed the virial velocity of the system. We propose that a massive gas disk surrounding a BH binary can effect its merger rapidly, in a scenario analogous to the orbital decay of super-Jovian planets due to a proto-planetary disk. As in the case of planets, gas accretion onto the secondary (here a supermassive BH) is integrally connected with its inward migration. Such accretion would give rise to quasar activity. BH binary mergers could therefore be responsible for many or most quasars.

Testing the Merger Paradigm: X-ray Observations of Radio-Selected Sub-Galactic-Scale Binary AGNs

NASA Astrophysics Data System (ADS)

Fu, Hai

2016-09-01

Interactions play an important role in galaxy evolution. Strong gas inflows are expected in the process of gas-rich mergers, which may fuel intense black hole accretion and star formation. Sub-galactic-scale binary/dual AGNs thus offer elegant laboratories to study the merger-driven co-evolution phase. However, previous samples of kpc-scale binaries are small and heterogeneous. We have identified a flux-limited sample of kpc-scale binary AGNs uniformly from a wide-area high-resolution radio survey conducted by the VLA. Here we propose Chandra X-ray characterization of a subset of four radio-confirmed binary AGNs at z 0.1. Our goal is to compare their X-ray properties with those of matched control samples to test the merger-driven co-evolution paradigm.

Rock Content Influence on Soil Hydraulic Properties

NASA Astrophysics Data System (ADS)

Parajuli, K.; Sadeghi, M.; Jones, S. B.

2015-12-01

Soil hydraulic properties including the soil water retention curve (SWRC) and hydraulic conductivity function are important characteristics of soil affecting a variety of soil properties and processes. The hydraulic properties are commonly measured for seived soils (i.e. particles < 2 mm), but many natural soils include rock fragments of varying size that alter bulk hydraulic properties. Relatively few studies have addressed this important problem using physically-based concepts. Motivated by this knowledge gap, we set out to describe soil hydraulic properties using binary mixtures (i.e. rock fragment inclusions in a soil matrix) based on individual properties of the rock and soil. As a first step of this study, special attention was devoted to the SWRC, where the impact of rock content on the SWRC was quantified using laboratory experiments for six different mixing ratios of soil matrix and rock. The SWRC for each mixture was obtained from water mass and water potential measurements. The resulting data for the studied mixtures yielded a family of SWRC indicating how the SWRC of the mixture is related to that of the individual media, i.e., soil and rock. A consistent model was also developed to describe the hydraulic properties of the mixture as a function of the individual properties of the rock and soil matrix. Key words: Soil hydraulic properties, rock content, binary mixture, experimental data.

Strong shock waves and nonequilibrium response in a one-dimensional gas: a Boltzmann equation approach.

PubMed

Hurtado, Pablo I

2005-10-01

We investigate the nonequilibrium behavior of a one-dimensional binary fluid on the basis of Boltzmann equation, using an infinitely strong shock wave as probe. Density, velocity, and temperature profiles are obtained as a function of the mixture mass ratio mu. We show that temperature overshoots near the shock layer, and that heavy particles are denser, slower, and cooler than light particles in the strong nonequilibrium region around the shock. The shock width omega(mu), which characterizes the size of this region, decreases as omega(mu) approximately mu(1/3) for mu-->0. In this limit, two very different length scales control the fluid structure, with heavy particles equilibrating much faster than light ones. Hydrodynamic fields relax exponentially toward equilibrium: phi(chi) approximately exp[-chi/lambda]. The scale separation is also apparent here, with two typical scales, lambda1 and lambda2, such that lambda1 approximately mu(1/2 as mu-->0, while lambda2, which is the slow scale controlling the fluid's asymptotic relaxation, increases to a constant value in this limit. These results are discussed in light of recent numerical studies on the nonequilibrium behavior of similar one-dimensional binary fluids.

Monte Carlo simulations of mixtures involving ketones and aldehydes by a direct bubble pressure calculation.

PubMed

Ferrando, Nicolas; Lachet, Véronique; Boutin, Anne

2010-07-08

Ketone and aldehyde molecules are involved in a large variety of industrial applications. Because they are mainly present mixed with other compounds, the prediction of phase equilibrium of mixtures involving these classes of molecules is of first interest particularly to design and optimize separation processes. The main goal of this work is to propose a transferable force field for ketones and aldehydes that allows accurate molecular simulations of not only pure compounds but also complex mixtures. The proposed force field is based on the anisotropic united-atoms AUA4 potential developed for hydrocarbons, and it introduces only one new atom, the carbonyl oxygen. The Lennard-Jones parameters of this oxygen atom have been adjusted on saturated thermodynamic properties of both acetone and acetaldehyde. To simulate mixtures, Monte Carlo simulations are carried out in a specific pseudoensemble which allows a direct calculation of the bubble pressure. For polar mixtures involved in this study, we show that this approach is an interesting alternative to classical calculations in the isothermal-isobaric Gibbs ensemble. The pressure-composition diagrams of polar + polar and polar + nonpolar binary mixtures are well reproduced. Mutual solubilities as well as azeotrope location, if present, are accurately predicted without any empirical binary interaction parameters or readjustment. Such result highlights the transferability of the proposed force field, which is an essential feature toward the simulation of complex oxygenated mixtures of industrial interest.

Soft repulsive mixtures under gravity: Brazil-nut effect, depletion bubbles, boundary layering, nonequilibrium shaking

NASA Astrophysics Data System (ADS)

Kruppa, Tobias; Neuhaus, Tim; Messina, René; Löwen, Hartmut

2012-04-01

A binary mixture of particles interacting via long-ranged repulsive forces is studied in gravity by computer simulation and theory. The more repulsive A-particles create a depletion zone of less repulsive B-particles around them reminiscent to a bubble. Applying Archimedes' principle effectively to this bubble, an A-particle can be lifted in a fluid background of B-particles. This "depletion bubble" mechanism explains and predicts a brazil-nut effect where the heavier A-particles float on top of the lighter B-particles. It also implies an effective attraction of an A-particle towards a hard container bottom wall which leads to boundary layering of A-particles. Additionally, we have studied a periodic inversion of gravity causing perpetuous mutual penetration of the mixture in a slit geometry. In this nonequilibrium case of time-dependent gravity, the boundary layering persists. Our results are based on computer simulations and density functional theory of a two-dimensional binary mixture of colloidal repulsive dipoles. The predicted effects also occur for other long-ranged repulsive interactions and in three spatial dimensions. They are therefore verifiable in settling experiments on dipolar or charged colloidal mixtures as well as in charged granulates and dusty plasmas.

Soft repulsive mixtures under gravity: brazil-nut effect, depletion bubbles, boundary layering, nonequilibrium shaking.

PubMed

Kruppa, Tobias; Neuhaus, Tim; Messina, René; Löwen, Hartmut

2012-04-07

A binary mixture of particles interacting via long-ranged repulsive forces is studied in gravity by computer simulation and theory. The more repulsive A-particles create a depletion zone of less repulsive B-particles around them reminiscent to a bubble. Applying Archimedes' principle effectively to this bubble, an A-particle can be lifted in a fluid background of B-particles. This "depletion bubble" mechanism explains and predicts a brazil-nut effect where the heavier A-particles float on top of the lighter B-particles. It also implies an effective attraction of an A-particle towards a hard container bottom wall which leads to boundary layering of A-particles. Additionally, we have studied a periodic inversion of gravity causing perpetuous mutual penetration of the mixture in a slit geometry. In this nonequilibrium case of time-dependent gravity, the boundary layering persists. Our results are based on computer simulations and density functional theory of a two-dimensional binary mixture of colloidal repulsive dipoles. The predicted effects also occur for other long-ranged repulsive interactions and in three spatial dimensions. They are therefore verifiable in settling experiments on dipolar or charged colloidal mixtures as well as in charged granulates and dusty plasmas.

Columnar to Nematic Mesophase Transition: Binary Mixtures of Unlike Copper Soaps

NASA Astrophysics Data System (ADS)

Seghrouchni, R.; Skoulios, A.

1995-10-01

Copper (II) soaps are known to produce columnar mesophases at high temperature. The polar groups of the soap molecules are stacked over one another within columns surrounded by the alkyl chains in a disordered conformation and laterally arranged according to a two-dimensional hexagonal lattice. The present work studies the mesomorphic behaviour of binary mixtures of copper soaps using differential scanning calorimetry, polarizing microscopy, and X-ray diffraction. When the soaps are of comparable molecular sizes the mixtures are homogeneous and columnar at all compositions. The columns of the two soaps, remaining intact in the mixture, are distributed randomly on the nodes of a hexagonal Bravais lattice. Crystallographic homogeneity is obtained by transfer of methylene groups from cell to cell. When, on the other hand, the soaps are different enough in molecular sizes, the columnar structure of the mixtures is interrupted in the middle range of compositions for the benefit of a nematic one. The transfer of methylene groups gets indeed harder to achieve and the distortion of the hexagonal units cells becomes important. The columnar to nematic phase transition is discussed on a molecular and a topological level.

Demixing, surface nematization, and competing adsorption in binary mixtures of hard rods and hard spheres under confinement

NASA Astrophysics Data System (ADS)

Wu, Liang; Malijevský, Alexandr; Avendaño, Carlos; Müller, Erich A.; Jackson, George

2018-04-01

A molecular simulation study of binary mixtures of hard spherocylinders (HSCs) and hard spheres (HSs) confined between two structureless hard walls is presented. The principal aim of the work is to understand the effect of the presence of hard spheres on the entropically driven surface nematization of hard rod-like particles at surfaces. The mixtures are studied using a constant normal-pressure Monte Carlo algorithm. The surface adsorption at different compositions is examined in detail. At moderate hard-sphere concentrations, preferential adsorption of the spheres at the wall is found. However, at moderate to high pressure (density), we observe a crossover in the adsorption behavior with nematic layers of the rods forming at the walls leading to local demixing of the system. The presence of the spherical particles is seen to destabilize the surface nematization of the rods, and the degree of demixing increases on increasing the hard-sphere concentration.

A comparative study of the use of powder X-ray diffraction, Raman and near infrared spectroscopy for quantification of binary polymorphic mixtures of piracetam.

PubMed

Croker, Denise M; Hennigan, Michelle C; Maher, Anthony; Hu, Yun; Ryder, Alan G; Hodnett, Benjamin K

2012-04-07

Diffraction and spectroscopic methods were evaluated for quantitative analysis of binary powder mixtures of FII(6.403) and FIII(6.525) piracetam. The two polymorphs of piracetam could be distinguished using powder X-ray diffraction (PXRD), Raman and near-infrared (NIR) spectroscopy. The results demonstrated that Raman and NIR spectroscopy are most suitable for quantitative analysis of this polymorphic mixture. When the spectra are treated with the combination of multiplicative scatter correction (MSC) and second derivative data pretreatments, the partial least squared (PLS) regression model gave a root mean square error of calibration (RMSEC) of 0.94 and 0.99%, respectively. FIII(6.525) demonstrated some preferred orientation in PXRD analysis, making PXRD the least preferred method of quantification. Copyright © 2012 Elsevier B.V. All rights reserved.

Demixing, surface nematization, and competing adsorption in binary mixtures of hard rods and hard spheres under confinement.

PubMed

Wu, Liang; Malijevský, Alexandr; Avendaño, Carlos; Müller, Erich A; Jackson, George

2018-04-28

A molecular simulation study of binary mixtures of hard spherocylinders (HSCs) and hard spheres (HSs) confined between two structureless hard walls is presented. The principal aim of the work is to understand the effect of the presence of hard spheres on the entropically driven surface nematization of hard rod-like particles at surfaces. The mixtures are studied using a constant normal-pressure Monte Carlo algorithm. The surface adsorption at different compositions is examined in detail. At moderate hard-sphere concentrations, preferential adsorption of the spheres at the wall is found. However, at moderate to high pressure (density), we observe a crossover in the adsorption behavior with nematic layers of the rods forming at the walls leading to local demixing of the system. The presence of the spherical particles is seen to destabilize the surface nematization of the rods, and the degree of demixing increases on increasing the hard-sphere concentration.

Simultaneous determination of binary mixture of amlodipine besylate and atenolol based on dual wavelengths

NASA Astrophysics Data System (ADS)

Lamie, Nesrine T.

2015-10-01

Four, accurate, precise, and sensitive spectrophotometric methods are developed for simultaneous determination of a binary mixture of amlodipine besylate (AM) and atenolol (AT). AM is determined at its λmax 360 nm (0D), while atenolol can be determined by four different methods. Method (A) is absorption factor (AF). Method (B) is the new ratio difference method (RD) which measures the difference in amplitudes between 210 and 226 nm. Method (C) is novel constant center spectrophotometric method (CC). Method (D) is mean centering of the ratio spectra (MCR) at 284 nm. The methods are tested by analyzing synthetic mixtures of the cited drugs and they are applied to their commercial pharmaceutical preparation. The validity of results is assessed by applying standard addition technique. The results obtained are found to agree statistically with those obtained by official methods, showing no significant difference with respect to accuracy and precision.

Novel spectrophotometric determination of flumethasone pivalate and clioquinol in their binary mixture and pharmaceutical formulation.

PubMed

Abdel-Aleem, Eglal A; Hegazy, Maha A; Sayed, Nour W; Abdelkawy, M; Abdelfatah, Rehab M

2015-02-05

This work is concerned with development and validation of three simple, specific, accurate and precise spectrophotometric methods for determination of flumethasone pivalate (FP) and clioquinol (CL) in their binary mixture and ear drops. Method A is a ratio subtraction spectrophotometric one (RSM). Method B is a ratio difference spectrophotometric one (RDSM), while method C is a mean center spectrophotometric one (MCR). The calibration curves are linear over the concentration range of 3-45 μg/mL for FP, and 2-25 μg/mL for CL. The specificity of the developed methods was assessed by analyzing different laboratory prepared mixtures of the FP and CL. The three methods were validated as per ICH guidelines; accuracy, precision and repeatability are found to be within the acceptable limits. Copyright © 2014 Elsevier B.V. All rights reserved.

Dielectric and electrical properties of binary mixtures of 1-butyl-3-methylimadazolium and water in the frequency range 20 Hz to 2 MHz

NASA Astrophysics Data System (ADS)

Barot, D. K.; Chaube, H. A.; Rana, V. A.

2017-05-01

The complex relative dielectric function ɛ*(ω) = ɛ'-jɛ″ of binary mixture of 1-Butyl-3-methylimadazolium (BMiCl) with water of varying concentration have been measured using Precision LCR meter in the frequency range 20 Hz to 2 MHz at 293.15 K. The dielectric and electrical properties of BMiCl and water are represented in terms of electrical conductivity σ*(ω) and complex relative dielectric function ɛ*(ω). To describe the relationship of the electrical conductivity with concentration, the empirical Casteel-Amis (C-A) equation was used. The influence of concentration variation of BMiCl in water to the various electrical parameters was discussed. All of these presentations are used to explore various processes contributed in the electrical/dielectric properties of the mixtures of BMiCl and water.

Solubility of Naproxen in Polyethylene Glycol 200 + Water Mixtures at Various Temperatures

PubMed Central

Panahi-Azar, Vahid; Soltanpour, Shahla; Martinez, Fleming; Jouyban, Abolghasem

2015-01-01

The solubility of naproxen in binary mixtures of polyethylene glycol 200 (PEG 200) + water at the temperature range from 298.0 K to 318.0 K were reported. The combinations of Jouyban-Acree model + van’t Hoff and Jouyban-Acree model + partial solubility parameters were used to predict the solubility of naproxen in PEG 200 + water mixtures at different temperatures. Combination of Jouyban-Acree model with van’t Hoff equation can be used to predict solubility in PEG 200 + water with only four solubility data in mono-solvents. The obtained solubility calculation errors vary from ~ 17 % up to 35 % depend on the number of required input data. Non-linear enthalpy-entropy compensation was found for naproxen in the investigated solvent system and the Jouyban−Acree model provides reasonably accurate mathematical descriptions of the thermodynamic data of naproxen in the investigated binary solvent systems. PMID:26664370