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A novel solid-phase microextraction Arrow was used to separate volatile organic compounds from soy sauce, and the results were verified by using gas chromatography with mass spectrometry. Solid-phase microextraction Arrow was optimized in terms of three extraction conditions: type of fiber used (polydimethylsiloxane, polyacrylate, carbon wide range/polydimethylsiloxane, and divinylbenzene/polydimethylsiloxane), extraction temperature (40, 50, and 60°C), and extraction time (10, 30, and 60 min). The optimal solid-phase microextraction Arrow conditions were as follows: type of fiber = polyacrylate, extraction time = 60 min, and extraction temperature = 50°C. Under the optimized conditions, the solid-phase microextraction Arrow was compared with conventional solid-phase microextraction to determine extraction yields. The solid-phase microextraction Arrow yielded 6-42-fold higher levels than in solid-phase microextraction for all 21 volatile organic compounds detected in soy sauce due to the larger sorption phase volume. The findings of this study can provide practical guidelines for solid-phase microextraction Arrow applications in food matrixes by providing analytical methods for volatile organic compounds.

Headspace sorptive extraction technique using silicone based sorptive media coated stir bars is used for the first time here to extract, identify, and quantify heavy volatile organic compounds present in Escherichia coli culture headspace. Detection of infection presence is largely accomplished in laboratories through physical sampling and subsequent growth of cultures for biochemical testing. The use of volatile biomarkers released from pathogens as indicators for pathogenic presence can vastly reduce the time needed whilst improving the success rates for infection detection. To validate this, by using a contactless headspace sorptive extraction technique, the volatile compounds released from E. coli, grown in vitro, have been extracted and identified. Two different sorptive media for extracting these headspace volatiles were compared in this study and the identified volatiles were quantified. The large phase volume and wider retention of this sorptive technique compared to traditional sampling approach enabled preconcentration and collection of wider range of volatiles towards developing an extensive database of such heavy volatiles associated with E. coli. This supplements the existing data of potential bacterial markers and use of internal standards in these tests allows semi-quantitative estimation of these compounds towards the development and optimization of novel pathogen sensing devices.

Tiny water droplets in oil emulsions are commonly encountered in the petroleum industry. The high viscosity of the oil hampers the physical separation of the water droplets from the oil.[1] Phase inversion could be a potential workaround for this problem by making water, a much less viscous phase, the continuous medium. In the present work, we focused on triggering phase inversion of a solid-stabilized emulsion. We induced a catastrophic phase inversion by the continuous addition of a dispersed phase. The evolution of droplet morphology during the phase inversion process was observed and was measured in-line using a particle vision microscope, which proved to be a powerful tool for monitoring this rapid, unstable process. A linear relationship between the droplet size and the dispersed phase volume fraction before the phase inversion was observed, indicating that a higher dispersed phase volume fraction was needed for the phase inversion to occur with higher particle concentrations. The phase inversion conditions were applied in a regime where the particles were insufficient to fully cover the interface. Our findings indicated that the number of particles per surface area appears to be a crucial parameter in triggering phase inversion, regardless of the particle concentration. The phase inversion mechanism of our solid-stabilized emulsion can be explained by the relationship between the initial particle coverage of the interface and the coalescence rate of the system.

– Pd and Ag partitioning between liquid Fe metallic sulfide and liquid silicate under plausible magma ocean conditions constrains potential core 107Ag content and the origin of observed Pd and Ag mantle abundances. DPdmetallic sulfide/silicate (element concentration in metallic liquid/concentration in silicate liquid) in our experiments is insensitive to S content and temperature, but increases with total Pd content. DPdmetallic sulfide/silicate at low Pd concentration ranges from approximately 150–650. Metallic sulfide Pd content and silicate Pd content anticorrelate in our study. A curved silicate saturation surface in the Fe sulfide–silicate Pd ternary can explain both the metallic sulfide–silicate Pd anticorrelation and interstudy differences in DPdmetallic sulfide/silicate behavior. The size and shape of the curved silicate phase volume may respond to physical and chemical conditions, reducing the general applicability of D calculations. Ag becomes decreasingly siderophile as S increases: DAgmetallic sulfide/silicate decreases from 144 at 0 wt% S to 2.5 at 28 wt% S added to the starting metal sulfide liquid. Model calculations indicate that 1% core material incorporated into the Hawai’ian plume would yield a 107Ag signature on the surface smaller than detectable by current analytical techniques. Observed Pd and Ag mantle depletions relative to bulk Earth are consistent with depletions calculated with the data from this study for a magma ocean scenario without additional accretionary input after core formation.

Yield stresses (τ) of whipped foams prepared from various ratios of native whey protein isolate (WPI) and polymerized whey protein isolate (pWPI) were characterized by means of vane rheometry Yield stress displayed a parabolic response to increasing concentrations of pWPI, peaking at 50%. Foam air phase volume steadily decreased with increasing pWPI content, whereas equilibrium surface tension steadily increased. Dynamic surface tension measurements revealed that native WPI adsorbed much more rapidly than pWPI, presumably because of the latter's larger size. Interfacial dilatational elasticity (E') displayed a parabolic trend with increasing pWPI content, peaking at 50%. This suggested that pWPI coadsorbs with native WPI, bolstering E' of native WPI interfaces. However, too much pWPI caused a weakening of the network. A positive, curvilinear relationship between E' and τ was observed, consistent with a previous observation for WPI foams formed at various pH levels and salt concentrations, further suggesting a general link between these parameters.

The influence of the additive SO 3 on the phase relationships in the quaternary system CaO-SiO 2 -Al 2 O 3 -Fe 2 O 3 was investigated by observing the change of volume ratio of 3CaO.SiO 2 (C 3 S) to 2CaO.SiO 2 (C 2 S) + CaO (C) in the sintered material with the increase of SO 3 content. The primary phase volume of C 3 S in the quaternary phase diagram shrank with the increase of SO 3 and disappeared when the SO 3 content exceeded 2.6 wt% in the sintered material. Changes in the peritectic reaction relationship between CaO (C), 2CaO.SiO 2 (C 2 S), 3CaO.SiO 2 (C 3 S), 3CaO.Al 2 O 3 (C 3 A), 4CaO.Al 2 O 3 .Fe 2 O 3 (C 4 AF), and liquid were also observed and discussed.

A literature review of numerical simulations of heat treatment was performed. The model used in the numerical simulation can be divided into three major parts that are mutually coupled: temperature calculation, phase transformation and mechanical response. The parts and couplings are introduced; examples, theoretical results and verifications of different models are presented to show the accuracy of the calculations compared with experiments. It was found that today, the simulations are performed in two steps, the calculation of temperature history 2-way coupled with phase transformation, and the mechanical response as a subsequent calculation of distortion and residual stresses taking the temperature history as well as the actual phase volume fractions into account. Research subjects are the diffusion-controlled phase transformation in non-isothermal cooling and the stress dependency of phase transformations. Other research topics concern the type of hardening as laser surface hardening.

A study of the phase inversion behavior of liquid-liquid dispersions in stirred vessels is performed for liquids of various physical properties at various operating conditions. Physical parameters studied are density (867 to 1180 kg/m3), viscosity (0.00096 to 0.00378 Pa·s), and interfacial tension (0.0089 to 0.0323 N/m). Ambivalence region plots are presented and compared with results reported in the literature. Experiments are performed to examine the effects of impeller type and impeller-to-tank diameter ratio (D/T) on the ambivalence behavior. Also, phase inversion time experiments are performed to investigate the time required for complete phase inversion under various dynamic conditions. The traditional method of plotting the organic phase volume fraction at phase inversion against the agitation speed at that condition is compared with the method of plotting the initially dispersed phase volume fraction at phase inversion against the agitation speed at that condition. A hysteresis phenomenon is shown in phase inversion from O/W to W/O and W/O to O/W dispersions. Also, it is shown that, depending on the physical properties of the dispersed and continuous phases, phase inversion may occur when the agitation speed is increased or decreased. On a mene une etude du comportement d'inversion de phases de dispersions liquide-liquide dans des reservoirs agites pour des liquides aux proprietes physiques diverses et dans differentes conditions de fonctionnement. Les parametres physiques etudies sont la masse volumique (867 a 1180 kg/m3), la viscosite (0,00096 a 0,00378 Pa·s) et la tension interfaciale (0,0089 a 0,0323 N/m). Des releves des regions d'ambivalence sont presentes et compares aux resultats de la litterature scientifique. Des experiences sont menees afin d'examiner les effets du type de turbine et du rapport du diametre de la turbine au diametre du reservoir (D/T) sur le comportement d'ambivalence. De měme, des experiences sur les temps d'inversion de phase sont menees pour etudier le temps requis pour une inversion de phase complete dans des conditions dynamiques variees. La methode traditionnelle de trace de la fraction volumique de la phase organique a l'inversion de phase par rapport a la vitesse d'agitation a cette condition est comparee a la methode de trace de la fraction volumique de phase dispersee initiale a l'inversion de phase par rapport a la vitesse d'agitation a cette condition. Un phenomene d'hysterese est montre dans l'inversion de phase des dispersions O/W a W/O et W/O a O/W. On montre egalement que, selon les proprietes physiques des phases dispersee et continue, l'inversion de phase peut survenir lorsque la vitesse d'agitation est augmentee ou diminuee.

Addition of locust bean gum (LBG) or guar gum to ice cream mixes gave products with smaller ice crystals after heatshock than control samples without either stabilizer. LBG was more effective at inhibiting recrystallization than guar. Increasing stabilizer concentration resulted in greater inhibition. With LBG we found some evidence for an optimum concentration above which no further inhibition occurred. We found no evidence for phase volume effects.

Using silicone copolymers in personal care products can improve the aesthetic performance of formulations. During their manufacture, distribution and topical application they are subject to various mechanical stresses. In this study rheology was used to measure their effects. A number of water in silicone (w/Si) emulsions were prepared in which the oil phase consisted of cyclomethicone. The surfactant used was a branched type silicone copolymer. Both viscoelastic and viscometry measurement were performed on model systems and on commercial products. Experimental data were obtained using a Bohlin rheometer. The measurements were taken applying shear rates in the range of 0.46-58 l s-1 and for the strain sweep frequencies of 0.1 Hz, 1 Hz and 10 Hz were applied. Oscillation tests were performed in the 0.1 Hz to 10 Hz range. All measurements were taken at 35deg;C, representing the approximate temperature encountered during topical application. The effect of surfactant concentration on viscoelastic properties was examined. It was shown that with increasing surfactant concentration the elastic moduli G' and the viscous moduli G" increased. Furthermore, the emulsions showed a transition from a predominantly elastic to a predominantly viscous response as the surfactant concentration increased. The effect of varying the water phase volume fraction on viscometry and viscoelastic measurements was also examined. With increasing water phase volume fraction the viscosity of the emulsions, as well as the yield stress, increased. The Cross and Sisko models were applied. From the Dougherty and Krieger equation φeff was calculated. It was found the the data derived from the Sisko model gave more reliable results. Results obtained from commercial samples showed a high proportion of elasticity; oscillation tests and viscometry experiments suggested that tumbling had the biggest impact on the theological profiles; viscosity, η, shear stress, σ, elastic module, G', and dynamic viscosity, η', dropped to a minimum in these samples. Results from the two commercial samples were compared and it was observed that, although both were w/o emulsions, different rheological behaviour could be observed. L'utilisation de copolymeres de silicone dans les produits d'hygiene personnelle peut ameliorer les caracteristiques esthetiques des formulations. Durant leur fabrication, leur distribution et leur application externe elles sont soumises a diverses contraintes mecaniques. Dans cette etude on a utilise la rheologie pour mesurer leurs effets. On a prepare un certain nombre d'emulsions eau/Si dans lesquelles la phase huile est constituee de cyclomethicone. Le tensioactif utilise est un copolymere de silicone de type ramifie. On a effectue des mesures de viscoelasticite et de viscosimetrie sur des systemes modelises et sur des produits du commerce. Les donnees experimentales ont ete obtenues avec un rheometre Bohlin. Les mesures ont ete prises avec des cisaillements compris entre 0.46 et 58 l.s, et pour la fatigue on a applique des frequences de 0.1 Hz, 1 Hz et 10 Hz. Les essais d'oscillation ont ete effectues dans le domaine compris entre 0.1 et 10 Hz. Toutes les mesures ont ete effectuees a 35°C, figurant la temperature approximative existant durant l'application externe. On a etudie l'effet de la concentration du tensioactif sur les proprietes viscoelastiques. On a montre que lorsque la concentration en tensioactif augmente les modules elastiques G' et les modules visqueux G" augmentent. En outre, les emulsions presentent une transition d'une transition d'une reponse majoritairement elastique a une reponse majoritairement visqueuse a mesure que la concentration en tensioactif augmente. On a aussi etudie l'effet de la variation de la fraction volumique de la phase aqueuse sur les mesures de viscosimetrie et de viscoelasticite. Lorsque la fraction volumique de la phase aqueuse augmente, viscosite et la contrainte d'ecoulement des emulsions augmentent. On a applique les modeles de Cross et Sisko, φ eff a ete calcule a partir de l'equation de Dougherty et Krieger. On a constate que les donnees derivees du modele de Sisko donnent des resultats plus fiables. Les resultats obtenus a partir des echantillons du commerce presentent une forte proportion d'elasticite; les essais d'oscillation et de viscosimetrie suggerent que c'est la centrifugation qui a l'impact le plus important sur les profils rheologiques; la viscosite, η, la contrainte de cisaillement, σ, le module elastique, G', et la viscosite dynamique, η', ont atteint leurs minima pour ces echantillons. Les resultats des deux echantillons du commerce ont ete compares et on a constate que, bien que les deux soient des emulsions e/h, on observait des comportements rheologiques differents.

Correlations between the Szigeti charge and the difference in phase volume in the alkali halides are presented. It is shown that the lattice bonding is enhanced if an alkali halide shows a bigger fractional change in volume at melting. The fractional change in volume for RbF can be obtained by extrapolation.

A simple and new model for the prediction of drop velocity as a function of dispersed phase volume fraction has been proposed on the basis of experimental knowledge of onset time of complete separation between two phases as function of the initial hold-up.

Control of crystallization of lipids is important in many food products, including margarine, chocolate, butter, and shortening. In these products, the aim is to produce the appropriate number and size distribution of crystals in the correct polymorphic form because the crystalline phase plays a large role in such food properties as appearance, texture, spreadability, and flavor release. Thus, understanding the processes that control crystallization is critical to controlling quality in these products. Controlling crystallization requires an understanding of the driving force that leads to crystallization, the process of forming the crystalline phase (nucleation), and then subsequent crystal growth and polymorphic transformation to obtain the final crystalline phase volume in equilibrium with the remaining liquid fat. Because of the complex composition of most natural fats, our understanding of these processes remains somewhat uncertain. Keywords: fats; lipids; crystallization; nucleation; polymorphism; crystal growth

Equations describing phase volumes in multicomponent, multiphase systems in the neighborhood of critical points are derived to aid in the location of such critical points. The theory is in good agreement with experiments for three ternary systems and four surfactant systems of the type used for tertiary oil recovery.

Mechanical properties of geleous fibres obtained from the liquid two-phase system of water — casein — sodium alginate have been studied in relation to the conditions of coagulation and the protein phase volume fraction. Mechanical strength, moduli of elasticity and relaxation of the fibres have been shown to exhibit a linear dependence on the volume fraction of the protein phase which can be accounted for by the anisotropic structure of the fibres obtained. These fibres can be referred to as a continuous phase matrix filled with oriented microfilaments of quasi-infinite length that arise from the dispersed phase. Functional characteristics of fibres differing in terms of the protein phase content have been investigated along with organoleptic properties of nutritive compositions. It has been established that artifical products based on two-phase fibres surpass those manufactured from monophasic ones with respect to organoleptic and technological properties.

The published Coulter Counter method for measuring particle size distribution of the discrete phase in rubber-modified polystyrene is shown to be subject to serious limitations, especially when the data generated are used to compute discrete phase volume fractions. The source of error is time-dependent swelling of the particles in DMF which is used to isolate them from the polystyrene matrix for the counting operation.

W/O/W type multiple emulsions were prepared by two step emulsification procedures using an oily lymphographic agent, lipiodol, as an inner oil phase and Pluronic F-68 as a hydrophilic emulsifier contained in the outer aqueous phase. Span 80, Pluronic L-64 and HCO-60 were used as emulsifiers incorporating them into the inner oil phase. The phase volume of the inner and outer aqueous phases and the yield of the w/o/w type multiple emulsions were studied. The dissolution behaviour of the w/o/w type multiple emulsions were determined by a dialysis method employing cellulose tubing. The effect of emulsifier type and the amount of HCO-60 on the stability and prolonged release behavior of the w/o/w type multiple emulsions with or without lecithin, was also examined. The results indicate the HCO-60 is a better emulsifier than Span 80 or Pluronic L-64. Its use improves the stability and the prolonged release behavior of w/o/w type multiple emulsions.

The first interfacial synthesis of polyalkyloxysilanes of the form where R′ = alkylene, and R″, R = alkyl or aryl is reported. It is found, in the range studied for the stirred systems, that as organic solvent viscosity and organic phase volume are increased, rate of polymer formation is decreased. Little difference in polymer formation rate is observed when the nature of the diol is varied, but considerable difference is noted when the nature of the organosilane is varied such that the most electropositive silane has the highest rate of polymer formation. Molecular weight is approximately constant as diol is changed but varies markedly when the silane is changed, so that the silane with the most bulky substance will give polymer with the lowest molecular weight.

These computations were formulated to answer some questions concerning variations in construction and operation of countercurrent distribution apparatus. An optimum, ideal separation was simulated for passage of two compounds through a countercurrent distribution, followed by simulation of several departures from the optimum. A significant decrease in separating efficiency was found to be produced by deviation of upper-lower volume ratio from the optimum value, retainment of a portion of the upper (traveling) phase after transfer, and originally introducing solute into more than one tube before beginning the transfers. Little effect on separating efficiency was produced by randomness in tube volumes or randomness in upper (traveling) phase volumes due to time variation of solvent input. Variations in the distribution ratios can also cause significant enhancement or deterioration in separating efficiency.

A new technique is derived for determining the concentration dependence of diffusion coefficients from sorption experiments. In this analysis the diffusion equation including the effects of phase volume change and volume change on mixing is solved by a weighted residual method to produce approximate analytical expressions which describe the sorption process. It is possible to deduce the concentration dependence of the diffusion coefficient from a single sorption experiment without assuming the form of the diffusivity-concentration relationship. A direct evaluation of the technique is obtained from the analysis of test data generated by finite-difference solutions of the equations which portray the sorption process.

Schairer's study (1954) on phase relations in the system KalSi2O6–Mg2SiO4–SiO2 was extended to include the system KalSiO4–Mg2SiO4–KalSi2O6. It is shown that this join is ternary; however, the relatively high vapor pressure of the condensed phases prohibits study by the usual quenching techniques. The apparent intersection of the (KalSiO4–Mg2SiO4–SiO3) join with the primary phase volume of spinel is attributed to loss of the alkali-silicate constituents by vapor transport. This results in the effective bulk composition being moved away from this join toward the primary phase volume of spinel in the system K2O–MgO–Al2O3–SiO2.