TY - CONF TI - A Mathematical Model of NASA’s Redox Flow Cell AU - Fedkiw, P. AU - Watts, R. T2 - Electrochemical Society.; Industrial Electrolytic Division A2 - Yeo, R.S. A2 - Katan, T. A2 - Chin, D-T C2 - 1982/// C3 - Proceedings of the Symposium on Transport Processes in Electrochemical Systems CY - Montreal, Quebec, Canada DA - 1982/// PY - 1982/// PB - Electrochemical Society ER - TY - CONF TI - Model Networks of End-Linked Polydimethylsiloxane Chains. XIV. : Some Dynamic Mechanical Properties of the Unimodal and Bimodal Networks AU - Andrady, A.L. AU - Llorente, M.A. AU - Mark, J.E. T2 - American Physical Society Meeting C2 - 1982/3// CY - Los Angeles, CA DA - 1982/3// PY - 1982/3// ER - TY - CONF TI - Theory of Dilute Solutions AU - Jonah, D.A. AU - Shing, K.S. AU - Gubbins, K.E. T2 - Eighth Symposium on Thermophysical Properties A2 - Sengers, J. V. C2 - 1982/// C3 - Proceedings of the Eighth Symposium on Thermophysical Properties CY - New York, NY, USA DA - 1982/// PY - 1982/// SP - 335 PB - American Society of Mechanical Engineers ER - TY - CONF TI - Experimental and Theoretical Studies of Dense Fluid Mixtures AU - Streett, W.B. AU - Gubbins, K.E. T2 - Eighth Symposium on Thermophysical Properties A2 - Sengers, J. V. C2 - 1982/// C3 - Proceedings of the Eighth Symposium on Thermophysical Properties CY - New York, NY, USA DA - 1982/// PY - 1982/// SP - 303 PB - American Society of Mechanical Engineers ER - TY - RPRT TI - Coal Gasification/Gas Cleanup Test Facility: Vol II: Environmental Assessment of Operation with Devolatilized Bituminous Coal and Chilled Methanol AU - Ferrell, J.K. AU - Felder, R.M. AU - Rousseau, R.W. AU - Ganesan, S. AU - Kelly, R.M. AU - McCue, J.C. AU - Purdy, M.J. A3 - U.S. Environmental Protection Agency DA - 1982/// PY - 1982/// M1 - EPA-600/7-82-023 PB - U.S. Environmental Protection Agency SN - EPA-600/7-82-023 ER - TY - RPRT TI - Coal Gasification/Gas Cleanup Test Facility, Vol III: Environmental Assessment of Operation with New Mexico Subbituminous Coal and Chilled Methanol AU - Ferrell, J.K. AU - Felder, R.M. AU - Rousseau, R.W. AU - Ganesan, S. AU - Kelly, R.M. AU - McCue, J.C. AU - Purdy, M.J. A3 - U.S. Environmental Protection Agency DA - 1982/// PY - 1982/// M1 - EPA-600/7-82-054 PB - U.S. Environmental Protection Agency SN - EPA-600/7-82-054 ER - TY - JOUR TI - The chemical potential in dense fluids and fluid mixtures via computer simulation AU - Shing, K.S. AU - Gubbins, K.E. T2 - Molecular Physics AB - We describe a new computer simulation technique to evaluate the chemical potential in dense fluids, where the usual test particle method fails. The method rests on the use of the well known Widom test particle equation in conjunction with another equation which is the inverse of the Widom equation. We show that the distribution functions (f and g, respectively) that describe the distribution of the test particle interaction energy u t for these two equations are exactly related (equation (10) below), and that g can be obtained accurately for the values of u t that are needed to calculate the chemical potential. This equation provides the basis for the method. We also propose a further refinement called ‘restricted umbrella sampling’, which improves the efficiency of placing the test particle in the fluid for a fixed configuration of real molecules. Detailed tests of the method are presented using the Monte Carlo technique, for both pure Lennard-Jones (LJ) fluids and LJ mixtures. We find that the method works for pure LJ fluids up to the triple point density, (at T* = 0·7 and 1·2) and for most mixtures except those involving a very large solute molecule. The method preserves the desirable feature of having a test particle that is not coupled in any way to the solvent. Thus it should be suitable for molecular dynamics calculations, and also for the evaluation of other properties besides the chemical potential. DA - 1982/8/10/ PY - 1982/8/10/ DO - 10.1080/00268978200101841 VL - 46 IS - 5 SP - 1109-1128 J2 - Molecular Physics LA - en OP - SN - 0026-8976 1362-3028 UR - http://dx.doi.org/10.1080/00268978200101841 DB - Crossref ER - TY - JOUR TI - The thermodynamics of symmetric two centre Lennard-Jones liquids AU - Wojcik, M. AU - Gubbins, K.E. AU - Powles, J.G. T2 - Molecular Physics AB - We have carried out molecular dynamic simulations for the thermodynamic properties of two centre Lennard-Jones fluids at lower densities and higher temperatures than have been studied previously, and have also made simulations for one additional shape. The results, together with results already given in the literature, are presented in a parameterized form which is very convenient to use in testing the simulation results against data for real liquids. Tables of second virial coefficients are also provided. We illustrate the use of our results by an analysis of pure liquid ethane, which is found to be well represented by such a model with L* = 0·67, ε/k = 137·5 K and σ = 3·506 Å. We also suggest that the experimental thermodynamic properties of suitable liquid mixtures can, with the aid of a theory for the equivalent pure liquid parameters (L x *, ε x , σ x ), be satisfactorily interpreted using the general results given in this paper. DA - 1982/4/20/ PY - 1982/4/20/ DO - 10.1080/00268978200100931 VL - 45 IS - 6 SP - 1209-1225 J2 - Molecular Physics LA - en OP - SN - 0026-8976 1362-3028 UR - http://dx.doi.org/10.1080/00268978200100931 DB - Crossref ER - TY - JOUR TI - Free energy and vapour-liquid equilibria for a quadrupolar Lennard-Jones fluid AU - Shing, K.S. AU - Gubbins, K.E. T2 - Molecular Physics AB - Monte Carlo (MC) calculations using umbrella sampling are reported for the free energy of a fluid of Lennard-Jones (LJ) molecules having an embedded quadrupole of strength Q*2=Q 2/εσ5=2·0. A wide range of temperatures and densities are studied for systems of 32 and 108 molecules, and the vapourliquid coexistence curve is calculated. System size is found to have very little effect, except on the coexistence curve close to the critical point. The MC results are compared with the predictions of the Padé approximant and generalized mean field (GMF—also known as the linearized hypernetted chain) theory. Good agreement is obtained at high temperatures, but the agreement is rather poorer at lower temperatures. The Padé theory is in better overall agreement with the MC calculations than is the GMF theory. The agreement of these theories with MC results is much better than for the dipolar hard sphere system, presumably because of the use of the LJ in place of the hard sphere model. DA - 1982/1// PY - 1982/1// DO - 10.1080/00268978200100101 VL - 45 IS - 1 SP - 129-139 J2 - Molecular Physics LA - en OP - SN - 0026-8976 1362-3028 UR - http://dx.doi.org/10.1080/00268978200100101 DB - Crossref ER - TY - JOUR TI - The phase‐change behavior of hydrogen in niobium and in niobium–vanadium alloys AU - Futran, Mauricio AU - Coats, Steve G. AU - Hall, Carol K. AU - Welch, David O. T2 - The Journal of Chemical Physics AB - A study was made of the phase-change behavior of hydrogen in niobium and in niobium–vanadium alloys. A lattice-gas model calculation for hydrogen in pure niobium in which no adjustable parameters are used predicts a critical point temperature of 460 K as compared with the experimental value of 443 K. More importantly, the shape of the coexistence curve corresponds quite closely to the shape of the coexistence curve found experimentally. The model is extended to the case where hydrogen is dissolved in the alloys Nb0.94V0.06, Nb0.85V0.15, and Nb0.75V0.25. The resulting phase diagram predicts a depression in the critical point temperature with increasing vanadium concentration in qualitative agreement with experiment. When the model is corrected to include the effect of trapping of hydrogen by vanadium atoms, the results are in quantitative agreement with experiment. DA - 1982/12/15/ PY - 1982/12/15/ DO - 10.1063/1.443824 VL - 77 IS - 12 SP - 6223-6235 J2 - The Journal of Chemical Physics LA - en OP - SN - 0021-9606 1089-7690 UR - http://dx.doi.org/10.1063/1.443824 DB - Crossref ER - TY - JOUR TI - Conformational state relaxation in polymers: Time‐correlation functions AU - Hall, Carol K. AU - Helfand, Eugene T2 - The Journal of Chemical Physics AB - A study is made of relaxation processes in polymer molecules which proceed via conformational transitions of the chain backbone from one rotational isomeric state to another. The conformational time-correlation functions are determined for several models of the process. Each model allows for the occurrence of both independent and cooperative conformational transitions. The resulting correlation functions contain a modified Bessel function which is associated with the diffusional nature of the process. This functional form has recently proven useful in fitting time-correlation functions determined in polymer simulations, which indicates that it will be of value in fitting data obtained in relaxation experiments on polymers. DA - 1982/9/15/ PY - 1982/9/15/ DO - 10.1063/1.444204 VL - 77 IS - 6 SP - 3275-3282 J2 - The Journal of Chemical Physics LA - en OP - SN - 0021-9606 1089-7690 UR - http://dx.doi.org/10.1063/1.444204 DB - Crossref ER - TY - JOUR TI - Mass-transfer coefficients in packed beds at very low reynolds numbers AU - Fedkiw, Peter S. AU - Newman, John T2 - International Journal of Heat and Mass Transfer AB - Accurate, transport-controlled, mass transfer coefficients for packed beds have been measured by an electrochemical technique at low Reynolds numbers (0.00271 < v/av < 0.198). At low Péclet numbers, the data show a strong dependence upon the bed length, but this dependence diminishes at the higher flow rates. The results are correlated by a dual-sized, straight-pore model for the bed's pore volume. The bed behaves as though 1.46% of the pore volume were in pores whose diameter is 56% greater than the diameter of the remaining pores. The larger pores result in a flow maldistribution and significantly reduce mass transfer at the lower Péclet numbers. Des coefficients de transfert massique ont été mesurés avec précision dans des lits fixes par la technique électrochimique aux faibles nombres de Reynolds (0,00271 < v/av < 0,198). Aux petits nombres de Péclet, les mesures montrent une forte dépendance vis-à-vis de la longueur du lit, mais cette dépendance diminue aux débits les plus élevés. Les résultats sont représentés par un modèle simple du volume des pores du lit. Le lit se comporte comme si 1,46% du volume de pore était dans les pores dont le diamètre est 56% plus grand que le diamètres des pores restant. Les plus grands pores causent une mauvaise distribution de l'écoulement et ils réduisent nettement le transfert massique aux plus faibles nombres de Péclet. Genaue, transportbestimmte Stoffübergangskoeffizienten für Festbetten wurden mit einem elektrochemischen Verfahren für kleine Reynolds-Zahlen gemessen (0,00271 < v/av < 0,198). Bei kleinen Péclet-Zahlen zeigen die Werte einen starken Einfluβ der Länge des Bettes, aber dieser Einfluβ verringert sich bei höheren Durchsätzen. Die Ergebnisse wurden mit Hilfe eines geraden Zwei-Gröβen-Porenmodells für das Porenvolumen des Bettes korreliert. Das Bett verhielt sich so, als ob 1,46% des Porenvolumens aus Poren bestände, deren Durchmesser 56% gröβer als der Durchmesser der verbleibenden Poren war. Die gröβeren Poren haben eine Verschlechterung der Strömungsverteilung zur Folge und verringern deutlich den Stoffübergang bei kleinen Péclet-Zahlen. Элeктpoчимичecким мeтoдoм пoлyчeнь тoчныe знaчeния кoeффициeнтoB мaccoп epeнoca плoтныч cлoeB пpи мaлыч знaчeнияч чиcлa Peйнoльдca (0,00271 < v/av < 0,198). B cлyчae мaлыч знaчeний чиcлa Пeклe нaблюдaeтcя cильнaя зaBиcимocть знaчeний кoэффициeнтoB oт длины cлoя, oднaкo этa зaBиcимocть yмeньшaeтcя c yBeличeниeм cкopocти тeчeния. peзyльтaты для пopиcтoгo oбъeмa cлoя oбoбщaютcя c иoмoщью дByчмepнoй мoдeли нpямыч пop. Cлoй Beдeт ceбя, кaк ecли бы 1,46% пopиcтoгo oбъeмa нaчoдилocь B пopaч, диaмeтp кoтopыч нa 56% пpeBыщaeт диaмeтp ocтaльныч пop. Пopы бoльшeгo paзмepa BызыBaют нapyшeния B pacпpeдeлeнии пoтoкa и знaчитeльнo cнижaют пepeнoc мaccы пpи бoлee мaлыч знaчeнняч чиcлa Пeклe. DA - 1982/7// PY - 1982/7// DO - 10.1016/0017-9310(82)90069-2 VL - 25 IS - 7 SP - 935-943 J2 - International Journal of Heat and Mass Transfer LA - en OP - SN - 0017-9310 UR - http://dx.doi.org/10.1016/0017-9310(82)90069-2 DB - Crossref ER - TY - JOUR TI - A collocation-finite difference procedure for an elliptic partial differential equation AU - Fedkiw, Peter S. T2 - Computers & Chemical Engineering AB - A numerical technique to solve a second order, linear, elliptic partial differential equation (PDE) is presented. Collocation is used in one coordinate direction to reduce the PDE to a set of coupled ODE. A second order finite-difference procedure is used to solve this system of ODE. Collocation is useful in emphasizing selected areas of the field and in obtaining accurate integrations over the field. Extensions of the procedure to non-linear problems, coupled PDE, and solutions with analytically identifiable singularities are discussed. DA - 1982/1// PY - 1982/1// DO - 10.1016/0098-1354(82)85008-4 VL - 6 IS - 4 SP - 327-330 J2 - Computers & Chemical Engineering LA - en OP - SN - 0098-1354 UR - http://dx.doi.org/10.1016/0098-1354(82)85008-4 DB - Crossref ER - TY - JOUR TI - OXIDATION OF AQUEOUS SULFUR-DIOXIDE .3. THE EFFECTS OF CHELATING-AGENTS AND PHENOLIC ANTIOXIDANTS AU - LIM, PK AU - HUSS, A AU - ECKERT, CA T2 - JOURNAL OF PHYSICAL CHEMISTRY AB - ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of aqueous sulfur dioxide. 3. The effects of chelating agents and phenolic antioxidantsP. K. Lim, A. Huss Jr., and C. A. EckertCite this: J. Phys. Chem. 1982, 86, 21, 4233–4237Publication Date (Print):October 1, 1982Publication History Published online1 May 2002Published inissue 1 October 1982https://doi.org/10.1021/j100218a029RIGHTS & PERMISSIONSArticle Views198Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (558 KB) Supporting Info (1)»Supporting Information Supporting Information Get e-Alerts DA - 1982/// PY - 1982/// DO - 10.1021/j100218a029 VL - 86 IS - 21 SP - 4233-4237 SN - 0022-3654 ER - TY - JOUR TI - OXIDATION OF AQUEOUS SULFUR-DIOXIDE .2. HIGH-PRESSURE STUDIES AND PROPOSED REACTION-MECHANISMS AU - HUSS, A AU - LIM, PK AU - ECKERT, CA T2 - JOURNAL OF PHYSICAL CHEMISTRY AB - ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of aqueous sulfur dioxide. 2. High-pressure studies and proposed reaction mechanismsA. Huss Jr., P. K. Lim, and C. A. EckertCite this: J. Phys. Chem. 1982, 86, 21, 4229–4233Publication Date (Print):October 1, 1982Publication History Published online1 May 2002Published inissue 1 October 1982https://doi.org/10.1021/j100218a028RIGHTS & PERMISSIONSArticle Views237Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (577 KB) Supporting Info (1)»Supporting Information Supporting Information Get e-Alerts DA - 1982/// PY - 1982/// DO - 10.1021/j100218a028 VL - 86 IS - 21 SP - 4229-4233 SN - 0022-3654 ER - TY - JOUR TI - OXIDATION OF AQUEOUS SULFUR-DIOXIDE .1. HOMOGENEOUS MANGANESE(II) AND IRON(II) CATALYSIS AT LOW PH AU - HUSS, A AU - LIM, PK AU - ECKERT, CA T2 - JOURNAL OF PHYSICAL CHEMISTRY AB - ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of aqueous sulfur dioxide. 1. Homogeneous manganese(II) and iron(II) catalysis at low pHA. Huss Jr., P. K. Lim, and C. A. EckertCite this: J. Phys. Chem. 1982, 86, 21, 4224–4228Publication Date (Print):October 1, 1982Publication History Published online1 May 2002Published inissue 1 October 1982https://doi.org/10.1021/j100218a027RIGHTS & PERMISSIONSArticle Views494Altmetric-Citations82LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (562 KB) Get e-Alerts DA - 1982/// PY - 1982/// DO - 10.1021/j100218a027 VL - 86 IS - 21 SP - 4224-4228 SN - 0022-3654 ER -