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Showing papers on "Ternary operation published in 1999"


Journal ArticleDOI
TL;DR: In this article, the gas adsorption equilibria of the gases CH4, N2, and CO2 and their binary and ternary mixtures on activated carbon Norit R1 Extra have been measured in the pressure range 0 ≤ P ≤ 6 MPa at T = 298 K.
Abstract: Adsorption equilibria of the gases CH4, N2, and CO2 and their binary and ternary mixtures on activated carbon Norit R1 Extra have been measured in the pressure range 0 ≤ P ≤ 6 MPa at T = 298 K. Pure gas adsorption equilibria were measured gravimetrically. Coadsorption data of the three binary mixtures CH4/N2, CH4/CO2, and CO2/N2 were obtained by the volume-gravimetric method. Isotherms of five ternary mixtures CH4/CO2/N2 were measured using the volumetric-chromatographic method. First, we present in a short overview the method and procedure of measurement. In a second part, the measured data of pressures, surface excess amounts adsorbed and absolute amounts adsorbed are presented and analyzed. In the last part of the paper the resulting pure gas adsorption data are correlated using a generalized dual-site Langmuir isotherm. Mixture adsorption can be predicted by this model using only pure component parameters with fair accuracy. Results are presented and discussed in several tables and figures.

360 citations


Journal ArticleDOI
TL;DR: In this article, the authors extended the theory of binary homogeneous nucleation to the ternary H2SO4-NH3-H2O system and showed that NH3 mixing ratios exceeding about 1 ppt enhances the binary H2 SO4-H 2O nucleation rate by several orders of magnitude.
Abstract: Classical theory of binary homogeneous nucleation is extended to the ternary system H2SO4-NH3-H2O. For NH3 mixing ratios exceeding about 1 ppt, the presence of NH3 enhances the binary H2SO4-H2O nucleation rate by several orders of magnitude. The Gibbs free energies of formation of the critical H2SO4-NH3-H2O cluster, as calculated by two independent approaches, are in substantial agreement. The finding that the H2SO4-NH3-H2O ternary nucleation rate is independent of relative humidity over a large range of H2SO4 concentrations has wide atmospheric consequences. The limiting component for ternary H2SO4-NH3-H2O nucleation is, as in the binary H2SO4-H2O case, H2SO4; however, the H2SO4 concentration needed to achieve significant nucleation rates is several orders of magnitude below that required in the binary case.

349 citations


Journal ArticleDOI
TL;DR: In this paper, binary lithium-silicon and ternary lithium-chromium-silicons were produced and then characterized by X-ray diffraction, as well as electrochemical methods at room temperature.

313 citations


Journal ArticleDOI
TL;DR: Transparent conducting oxide (TCO) films were prepared in multicomponent oxides composed of ZnO, SnO2, GaInO3, or MgO combined with In2O3 or ZnCo combined with SnCo as mentioned in this paper.
Abstract: Transparent and conductive thin films of multicomponent oxides composed of binary and/or ternary compounds with varied chemical compositions have been prepared by rf or dc magnetron sputtering. Transparent conducting oxide (TCO) films were prepared in multicomponent oxides composed of ZnO, SnO2, Ga2O3, or MgO combined with In2O3 or ZnO combined with SnO2, containing ternary compounds such as Zn2In2O5, In4Sn3O12, GaInO3, MgIn2O4, and ZnSnO3. In addition, the TCO films were prepared in a multicomponent oxide composed of combinations of these ternary compounds. In particular, the Zn2In2O5 and In4Sn3O12 films exhibited a resistivity of 2×10−4 Ω cm, comparable to that of indium–tin–oxide films. TCO films could always be obtained in multicomponent oxides consisting of combinations of metal oxides as long as these oxides were TCO film materials or transparent conductors; the mixture ratio of the components could be varied over all possible compositions. The electrical, optical, and chemical properties, the band-...

222 citations


Journal ArticleDOI
TL;DR: In this article, the effect of natural organic matter (NOM) on metal ion sorption to mineral surfaces is a complex function of the environment in which the mineral and ions reside, as well as the source, molecular weight distribution and composition of the NOM.

220 citations


Journal ArticleDOI
K. Kadir, N. Kuriyama, Tetsuo Sakai, I. Uehara, Lars Eriksson1 
TL;DR: In this paper, a ternary magnesium-based alloy CaMg 2 Ni 9 has been synthesized, and its crystal structure was determined by Guinier-Hagg X-ray and neutron powder diffraction.

174 citations


Journal ArticleDOI
TL;DR: In this article, a channel of bicontinuous microemulsion was identified in three chemically distinct hompolymer/hompolymers/block copolymer (A/B/A−B) ternary bends.
Abstract: We have identified a channel of bicontinuous microemulsion in three chemically distinct hompolymer/hompolymer/block copolymer (A/B/A−B) ternary bends. Experiments were conducted along the isopleth, defined by equal volumes of homopolymer and varying amounts of block copolymer, as a function of temperature. A symmetric condition was achieved through the use of homopolymers with matched degrees of polymerization (NA ≈ NB = NH) and compositionally symmetric diblock copolymers (f ≈ 0.5) where α ≡ NAB/NH ≈ 0.2. We explored PE−PEP/PE/PEP (EP), PEE−PDMS/PEE/PDMS (EED), and PE−PEO/PE/PEO (EO) ternary systems differing in molecular weight by nearly 2 orders of magnitude. Using a combination of small-angle neutron scattering (SANS), rheology, and cloud point measurements, we mapped the phase diagram along the isopleth for each of these systems. On the block-copolymer-rich side of the phase diagrams, a line of lamellar-disorder transitions was observed. On the homopolymer-rich side of the phase diagrams a line of tr...

172 citations


Journal ArticleDOI
TL;DR: In this article, a photoinduced magnetic pole inversion was proposed, which occurs even in the absence of an external magnetic field, where the compensation temperature is controlled by a pure photoprocess.
Abstract: We show a novel magnetic phenomenon, “photoinduced magnetic pole inversion”, which occurs even in the absence of an external magnetic field. The key of this strategy is to control the compensation temperature by a pure photoprocess. Here, we combined two magnetic behaviors which were developed recently. One of them is the photoinduced change of magnetization for some of the Prussian blue analogues. The other is a so-called mixed ferro-ferrimagnetism in the system of ternary metal Prussian blue analogues. We show a strategy to obtain this phenomenon based on molecular field (MF) theory and we design new classes of ternary metal Prussian blue analogues, (FeIIxMnII1-x)1.5[CrIII(CN)6]·zH2O, including photosensitive FeII−CrIII sites. Their magnetic properties, such as saturation magnetization, coercive field, Curie temperature, and compensation temperature, were controlled by changing the compositional factor x. When the material for x = 0.40 was irradiated by visible light under a weak external magnetic field...

154 citations



Journal ArticleDOI
TL;DR: In this article, the phase equilibria in the Y2O3-Al 2O3 −SiO3 -SiO2 system at 1600, 1400, and 1300 °C were experimentally determined using x-ray diffraction (XRD), scanning electron microscope with attached energy-dispersive detector system (SEM-EDX), and electron probe microanalyzer (EPMA).
Abstract: In order to clarify inconsistencies in the literature and to verify assumed ternary solubilities, the phase equilibria in the Y2O3–Al2O3 –SiO2 system at 1600, 1400, and 1300 °C were experimentally determined using x-ray diffraction (XRD), scanning electron microscope with attached energy-dispersive detector system (SEM-EDX), and electron probe microanalyzer (EPMA). Six quasibinary phases were observed: Y4Al2O9 (YAM), YAlO3 (YAP), Y3Al5O12 (YAG), Y2SiO5, Y2Si2O7 (C and D modifications), and ˜3Al2O3· 2SiO2 (mullite). Y4Al2O9 forms an extended ternary solid solution with the formula Y4Al2(1-x)Si2xO9+x (x = 0 2 ˜0.31). The lowest ternary eutectic temperature was determined at 1371 ± 5 °C by high-temperature differential scanning calorimetry (DSC). The results were compared with previous data available for the Y2O3–Al2O3 –SiO2 system and with data for other RE2O3–Al2O3 –SiO2 (RE = rare earth element) systems.

133 citations


Journal ArticleDOI
TL;DR: Water activities of binary and ternary poly(ethylene glycol)s (PEGs) solutions, at 298 K, were measured with an Aqua Lab CX-2 dew point device as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the phase equilibria and thermodynamic properties of the ternary Al-Fe-Si system were analyzed and a complete thermodynamic description of the system was obtained.
Abstract: The phase equilibria and thermodynamic properties of the ternary Al-Fe-Si system were analyzed and a complete thermodynamic description of the ternary system was obtained. The thermodynamic descriptions of the three binary systems were taken from the literature. Most of the binary intermetallic phases, except Al13Fe4(ϑ), FeSi2-L, and FeSi2-H, were assumed to have no ternary solubility. Based on the experimental data, seven stable ternary intermetallic phases were considered in the system. Two of them were treated as semistoichiometric compounds with homogeneity ranges for Al and Si, and the others were treated as stoichiometric compounds. Reasonable agreement was obtained between calculation results and experimental information in the ternary system.

Journal ArticleDOI
TL;DR: In this paper, a new analysis is presented for the determination of average values for the main and cross-interdiffusion coefficients over selected regions in the diffusion zone from an integration of interdiffusion fluxes, which are calculated directly from experimental concentration profiles.
Abstract: Concentration profiles that develop in a ternary diffusion couple during an isothermal anneal can be analyzed directly for average ternary interdiffusion coefficients. A new analysis is presented for the determination of average values for the main and cross-interdiffusion coefficients over selected regions in the diffusion zone from an integration of interdiffusion fluxes, which are calculated directly from experimental concentration profiles. The analysis is applied to selected isothermal diffusion couples investigated with α (fcc) Cu-Ni-Zn alloys at 775 °C, β (bcc) Fe-Ni-Al alloys at 1000 °C, and γ (fcc) Ni-Cr-Al alloys at 1100 °C. Average ternary interdiffusion coefficients treated as constants are calculated over composition ranges on either side of the Matano plane and examined for the diffusional interactions among the diffusing components. The ternary interdiffusion coefficients determined from the new analysis are observed to be consistent with those determined by the Boltzmann-Matano analysis at selected compositions in the diffusion zone. The ternary interdiffusion coefficients are also employed in analytical solutions based on error functions for the generation of concentration profiles for the selected diffusion couples. The generated profiles are a good representation of the experimental profiles including those exhibiting uphill diffusion or zero-flux plane (ZFP) development for the individual components. Uncertainties in the values of the interdiffusion coefficients calculated on the basis of the new analysis are found to be minimal.

Journal ArticleDOI
TL;DR: In this article, Bismuth additions of 1% to 10% were made to the 96.5Sn-3.33Ag-4.83Bi/Cu couples resulted in the growth of an intermetallic compound layer at the solder/substrate interface comprised of Cu3Sn and the Cu6Sn5 sublayers.
Abstract: Bismuth additions of 1% to 10% were made to the 96.5Sn-3.5Ag (wt.%) alloy in an effort to develop a Sn-Ag-Bi ternary composition. A DSC evaluation of the melting properties of the 91.84Sn-3.33Ag-4.83Bi composition suggested the appearance of metastable, short-range order in the atomic structure as a result of low temperature, thermal aging. More extensive solid-state aging studies on 91.84Sn-3.33Ag-4.83Bi/Cu couples resulted in the growth of an intermetallic compound layer at the solder/substrate interface comprised of Cu3Sn and the Cu6Sn5 sub-layers. The growth kinetics of the total layer thickness (x) as a function of solid-state aging time (t) and temperature (T) were represented by the following expression: $$x - x_o = A t^n \exp ( - Q/RT)$$ where x0=0.57 × 10−6 m; A=6.22 × 10−3 m/sn; n=0.46±0.15; and Q=49±8 kJ/mol. TEM analysis of the 91.84Sn-3.33Ag-4.83Bi composition indicated that solid-solution and precipitation strengthening mechanisms were a likely consequence of the Bi additions. Contact angle measurements, Cu/solder/Cu solder joint shear strength tests, and microhardness evaluations were also performed on the Sn-Ag-Bi alloys; those results are reported in Part II.

Journal ArticleDOI
TL;DR: In this paper, phase equilibrium and thermodynamic data of the Ni-Al-Cr ternary system were reviewed and analyzed by thermodynamic modeling, and a self-consistent thermodynamic description was obtained by optimization.

Journal ArticleDOI
TL;DR: A novel ceramic array microreactor system has been designed and, in conjunction with resonance-enhanced multiphoton ionization (REMPI), used for the discovery of an optimum ternary catalyst composition for the dehydrogenation of cyclohexane to benzene.
Abstract: A novel ceramic array microreactor system has been designed and, in conjunction with resonance-enhanced multiphoton ionization (REMPI), used for the discovery of an optimum ternary catalyst composition for the dehydrogenation of cyclohexane to benzene. The catalyst library consisted of 66 ternary combinations of Pt, Pd, and In loaded on γ-Al2 O3 pellets. The optimum catalyst for the production of benzene had the composition 0.8 % Pt, 0.1 % Pd, and 0.1 % In (see diagram). The preparation and screening of the library of 66 catalysts took about 2.5 days to complete-with conventional methods this would have taken several months!

Journal ArticleDOI
TL;DR: In this paper, the ammonolysis reaction has been applied first to the preparation of two binary molybdenum nitrides: Mo============ 5======N============ 6============ (filled 2H-MoS====== 2============ structure) and δ-MoN (NiAs-type structure) from MoS============ 3======
Abstract: Transition metal nitrides form a class of materials with unique physical properties which give them varied applications, as high temperature ceramics, magnetic materials, superconductors or catalysts. They are commonly prepared by high temperature conventional processes, but alternative synthetic approaches have also been explored, more recently, which utilize moderate-temperature conditions. For example, high surface area γ-Mo 2 N nitride powders (fcc phase) are prepared from commercial oxide MoO 3 through a topotactic transformation process. Of prime importance is the nature of the precursor, because it may yield new nitride phases unattainable by other synthetic routes. A novel promising method to nitride synthesis has been developed using sulfides as starting materials. The ammonolysis reaction has been applied first to the preparation of two binary molybdenum nitrides: Mo 5 N 6 (filled 2H-MoS 2 structure) and δ-MoN (NiAs-type structure) from MoS 2 , and then extended to other metals such as W, Cr or Ti, as well as molybdenum- and tantalum-based ternary systems. Fine reactive molybdenum sulfide precursor powders (S g ≥200 m 2 g –1 ) have been synthesized in thiocyanate melt. On the other hand, alkali metal ternary oxides offer potential as nitridation precursors. For example, a binary nitride Nb 4 N 5 (defect NaCl-type structure) results from ammonolysis of sodium or potassium niobates whereas LiNb 3 O 8 is transformed into a mixed valent ternary nitride LiNb 3 N 4 (filled 2H-MoS 2 structure). Another illustration of the Li + inductive effect is given in the direct synthesis of LiMN 2 from Li 2 MO 4 (M=Mo, W). The nitrides Mo 5 N 6 , δ-MoN and Nb 4 N 5 show superconducting behavior at T<12 K.

Journal ArticleDOI
TL;DR: In this paper, Bismuth additions of 1% to 10% were made to the 96.5Sn-3.33Ag-4.5Ag (wt.%) alloy in a study to develop a Sn-Ag-Bi ternary composition.
Abstract: Bismuth additions of 1% to 10% were made to the 96.5Sn-3.5Ag (wt.%) alloy in a study to develop a Sn-Ag-Bi ternary composition. Thermal properties and microstructural analyses of selected alloy compositions were reported in Part I. Wettability and mechanical properties are described in this paper. Contact angle measurements demonstrated that Bi additions improved wetting/spreading performance on Cu; a minimum contact angle of 31±4° was observed with 4.83 wt.% Bi addition. Increasing the Bi content of the ternary alloy raised the Cu/solder/Cu solder joint shear strength to 81 MPa as determined by the ring-and-plug tests. TEM analysis of the 91.84Sn-3.33Ag-4.83Bi composition presented in Part I indicated that the strength improvement was attributed to solid-solution and precipitation strengthening effects by the Bi addition residing in the Sn-rich phase. Microhardness measurements of the Sn-Ag-Bi alloy, as a function of Bi content, reached maximum values of 30 (Knoop, 50 g) and 110 (Knoop, 5 g) for Bi contents greater than approximately 4–5 wt.%.

Journal ArticleDOI
TL;DR: In this paper, simplified distillation columns for ternary separation with two, two-way connections between the columns are proposed, which can replace the fully thermally coupled system of columns without any increase in energy demand.
Abstract: The fully thermally coupled system of distillation columns for ternary separation has two, two-way connections between the columns. New, simplified (and easier to control) systems of columns for ternary separations, with a reduced number of connecting streams, are proposed. The new systems contain one one-way and one two-way connection between the columns. Depending on which connection is located on top and which phase stream (liquid or vapor) is used in the one-way connection, there are four possible configurations for these new systems. For certain feed compositions and relative volatilities of components, these new systems can replace the fully thermally coupled system of columns without any increase in energy demand. The optimum system selected from the four proposed configurations consumes no more, and frequently much less, energy than the side stripper or side rectifier configurations or than a system with a prefractionator.

Journal ArticleDOI
01 Jan 1999-Langmuir
TL;DR: In this paper, the aggregation and phase behavior, micelle and microemulsion structure, and polymerization behavior of various binary and ternary systems containing water, (oligooxa)alkanediyl-alpha,omega-bis(dimethyldodecylammonium bromide) surfactants (12-EOx-12),
Abstract: The aggregation and phase behavior, micelle and microemulsion structure, and the polymerization behavior of various binary and ternary systems containing water, (oligooxa)alkanediyl-alpha,omega-bis(dimethyldodecylammonium bromide) surfactants (12-EOx-12),

Journal ArticleDOI
TL;DR: In this paper, the simultaneous synthesis and densification of the ternary Ti3SiC2 was investigated by the field-activated, pressure-assisted combustion method, and the results suggest a two-mechanism process, one dominating in the approximate range of 800-950 °C and the other in the range 950-1100 °C with corresponding activation energies of 137.7 and 312.5 kJ·mol−1.
Abstract: The simultaneous synthesis and densification of the ternary Ti3SiC2 was investigated by the field-activated, pressure-assisted combustion method. Depending on temperature and time at temperature, relatively pure and nearly fully dense materials can be synthesized by this approach. The optimum conditions to produce this phase were a reaction temperature of 1525 °C and a time at temperature of 2 h. The product contained TiC as a second phase at a level of ≤2 mol%. The resulting ternary phase has typically elongated grains which were about 25 μm in size. Within a range of applied force of 1–4 N, the microhardness of the product was relatively constant, ranging from 6 to 7 GPa. Investigations on the thermal and chemical stabilities of the ternary were also conducted. Vacuum annealing at temperatures of 1600 and 2000 °C resulted in the formation of a surface layer of TiC, while the air annealing at 1000 °C resulted in the formation of TiO2. Oxidation studies on the prepared Ti3SiC2 were made at temperatures ranging from 800 to 1100 °C. The results suggest a two-mechanism process, one dominating in the approximate range of 800–950 °C and the other in the range 950–1100 °C with corresponding activation energies of 137.7 and 312.5 kJ·mol−1. The results are explained in terms of two proposed reactions on the basis of microprobe analyses.

Journal ArticleDOI
TL;DR: In this article, the binary Ni-Si phase diagram is reassessed and a consistent set of thermodynamic parameters are obtained based on literature data which they could verify experimentally (15 samples involving arc melting, annealing, water quenching, X-ray diffraction (XRD), and differential thermal analysis (DTA)).
Abstract: The binary Ni-Si phase diagram is reassessed and a consistent set of thermodynamic parameters is obtained based on literature data which we could verify experimentally (15 samples involving arc melting, annealing, water quenching, X-ray diffraction (XRD), and differential thermal analysis (DTA)). Applying this description of the Ni-Si system, as well as the descriptions of the Ni-C and Si-C systems available from the literature, preliminary calculations for the C-Ni-Si phase equilibria were made in order to provide guidance in selecting the compositions of decisive ternary alloys. These alloys were subjected to an experimental procedure similar to that employed for the Ni-Si alloys. The XRD and DTA measurements resulting from these ternary alloys provided accurate information on the invariant reaction temperatures in the C-Ni-Si system. Comprehensive comparisons between calculated and measured phase diagrams show that most of the experimental information is satisfactorily accounted for by the present description of the C-Ni-Si system. The liquidus projection and reaction scheme for the whole ternary system are presented.

Journal ArticleDOI
TL;DR: In this paper, a consistent set of thermodynamic functions for the Mg-Ni-H system has been developed from experimental data, and the mg−Ni−H phase diagram has been calculated thermodynamically.

Journal ArticleDOI
TL;DR: In this article, the phase relations in the ternary system Al±Ni±Ti have been experimentally established for the isothermal section at 900°C for concentrations 0.1 4 x Al 4 0.7.

Journal ArticleDOI
TL;DR: In this article, a model of dissolution and isothermal solidification during the transient liquid phase (TLP) bonding process of nickel using Ni-15.2wt.%Cr-4.0wt.
Abstract: A model of dissolution and isothermal solidification during the transient liquid phase (TLP) bonding process of nickel using Ni-15.2wt.%Cr-4.0wt.%B ternary filler metal is presented. The model combined thermodynamic calculation with Thermo-Calc software and diffusion analysis by a finite difference method. The model assumed diffusion-controlled transformation, and the equilibrium compositions at the solid-liquid interface were calculated using Thermo-Calc software. The interface velocity was determined from the mass balance of solutes diffusing into or out from the interface. When a Ni specimen with a 30 µm thick filler metal was kept at 1473 K for 3.6 ks, isothermal solidification was almost complete. On the other hand, when the specimen was kept at 1373 K for 3.6 ks, residual liquid remained in the bonding region. The solidification sequence of the residual liquid during the cooling stage was calculated by the Scheil simulation. The simulation showed that solidification of the residual liquid is completed with a ternary eutectic reaction, L→fcc+Ni3B+CrB. The calculated width of the eutectic region concurred with the experimental result.

Journal ArticleDOI
TL;DR: In this paper, a thermodynamic description of the Nb-Si-Ti ternary system is developed by modeling the Gibbs energies of the individual phases in the system, which is obtained primarily by extrapolation based on the descriptions of the constituent binary systems.

Journal ArticleDOI
TL;DR: In this article, a mathematical model was developed to simulate column dynamics of pure and mixed-vapor adsorption systems, and an empirical correlation was proposed to represent the overall mass transfer rates for the BTX vapor-activated carbon system.
Abstract: Experimental and theoretical studies were made on the adsorption of benzene, toluene, p-xylene, and their binary and ternary mixtures by activated carbon in an isothermal condition of 303 K. Experimental isotherms for pure components were measured by two kinds of experimental techniques: the static volumetric method and breakthrough data analysis. Breakthrough data analysis shows that both the extended Langmuir equation and the ideal adsorbed solution theory could explain mixture isotherm data with good accuracy. In addition, a mathematical model was developed to simulate the column dynamics of pure and mixed-vapor adsorption systems. To represent the mass-transfer rate inside the adsorbent particle, the linear driving-force approximation model was applied. By optimizing the pure- and the binary-component breakthrough curve data with a dynamic model, an empirical correlation was proposed to represent the overall mass-transfer rates for the BTX vapor-activated carbon system. Results with this correlation, which is a function of the partial pressures for each adsorbate and interstitial bulk fluid velocities, showed that the prediction agrees well with the experimental data of ternary breakthrough curves.

Journal ArticleDOI
TL;DR: In this article, the authors measured the ternary diffusion coefficient matrix for a protein, hen egg-white lysozyme (component 1) in aqueous NaCl (component 2) at pH 4.5 and 25 °C.
Abstract: Accurate models of protein diffusion are important in a number of applications, including liquid−liquid phase separation and growth of protein crystals for X-ray diffraction studies. In concentrated multicomponent protein systems, significant deviations from pseudobinary behavior can be expected. Rayleigh interferometry is used to measure the four elements (Dij)v of the ternary diffusion coefficient matrix for the extensively investigated protein, hen egg-white lysozyme (component 1) in aqueous NaCl (component 2) at pH 4.5 and 25 °C. These are the first multicomponent diffusion coefficients measured for any protein system at concentrations high enough to be relevant to modeling and prediction of crystal growth or other phase transitions, and the first for a system involving lysozyme at any concentration. The four ternary diffusion coefficients for the system lysozyme chloride/NaCl/water are reported for lysozyme chloride at 0.60 mM (8.6 mg/mL) and NaCl at concentrations of 0.25, 0.50, 0.65, 0.90, and 1.30...

Journal ArticleDOI
TL;DR: In this paper, the diffusion coefficients required to describe molecular transport in multicomponent systems can be easily predicted from self-diffusion coefficients and thermodynamic information when the mass flux with respect to the mass-average velocity is expressed in terms of the frictional force experienced by a molecule as it undergoes Brownian motion.
Abstract: Although most industrial drying and separation technologies are based on transport of multiple components, a convenient and practical means of describing multicomponent diffusion over wide temperature and concentration ranges has not been developed for polymer solutions or even for simple liquid mixtures. We have been able to demonstrate that all of the diffusion coefficients required to describe molecular transport in multicomponent systems can be easily predicted from self-diffusion coefficients and thermodynamic information when the mass flux with respect to the mass-average velocity is expressed in terms of the frictional force experienced by a molecule as it undergoes Brownian motion. This approach enables the flux equations for any combination of materials to be written in terms of experimentally measurable quantities. The model was tested by: (1) predicting literature data for principal diffusion coefficients in a ternary system; (2) applying the diffusion model to predict the drying behavior of three ternary systems; (3) predicting experimental values of the principal and cross coefficients for a ternary organic solvent mixture from self-diffusion data measured by PFG-NMR and available thermodynamic data; and (4) examining whether the limiting cases in this model are physically realistic. The applicability of the model to gas transport and polymer interdiffusion is also briefly examined.

Journal ArticleDOI
TL;DR: In this article, the growth of ternary AlGaN and InGaN by molecular beam epitaxy was studied, leading to a quantitative model describing alloy composition and growth rate as a function of group III fluxes, N flux and growth temperature.
Abstract: We report on a study of the growth of ternary AlGaN and InGaN by molecular beam epitaxy, leading to a quantitative model describing the alloy composition and growth rate as a function of group III fluxes, N flux and growth temperature. For low growth temperatures, the composition is exclusively determined by the different bond strengths between the group III elements and N, leading to a complete displacement of the more weakly bound species. The In loss from InGaN observed for typical growth conditions is caused by thermal decomposition of the growing layer with an activation energy between 3.5 and 3.8 eV depending on the In content.