Dissertations / Theses: 'Pure and mixed solvent systems'

1

Dakua, Vikas Kumar. "Physico-chemical studies on interactions between ion-solvent, ion-ion and solvent-solvent in aqueous and non-aqueous pure and mixed solvent systems." Thesis, University of North Bengal, 2008. http://hdl.handle.net/123456789/707.

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Barman, Biraj Kumar. "Investigation of diverse interactions and inclusion complexation in different environment by physicochemical methodology." Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2622.

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3

Brahman, Dhiraj. "PHYSICO-CHEMICAL STUDIES OF SOME SCHIFF BASE COMPLEXES OF TRANSITION METALS IN PURE AND MIXED SOLVENT MEDIA." Thesis, University of North Bengal, 2013. http://hdl.handle.net/123456789/973.

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4

Hamilton, Patrick Neal. "The behavior and separation of polystyrene in mixed solvent systems." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1256.

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5

Mullins, Paul Eric. "Application of COSMO-SAC to Solid Solubility in Pure and Mixed Solvent Mixtures for Organic Pharmacological Compounds." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31086.

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In this work, we present two open literature databases, the VT-2005 Sigma Profile Database and the VT-2006 Solute Sigma Profile Database, that contain sigma profiles for 1,645 unique compounds. A sigma profile is a molecular-specific distribution of the surface-charge density, which enables the application of solvation-thermodynamic models to predict vapor-liquid and solid-liquid equilibria, and other properties. The VT-2005 Sigma Profile Database generally focuses on solvents and small molecules, while the VT-2006 Solute Sigma Profile Database primarily consists of larger, pharmaceutical-related solutes. We design both of these databases for use with the conductor-like screening model â segment activity coefficient (COSMO-SAC), a liquid-phase activity-coefficient model. The databases contain the necessary information to perform binary and multicomponent VLE and SLE predictions. We offer detailed tutorials and procedures for use with our programs so the reader may also use their own research on our research group website (www.design.che.vt.edu). We validate the VT-2005 Sigma Profile Database by pure component vapor pressure predictions and validate the VT-2006 Solute Sigma Profile Database by solid solubility predictions in pure solvents compared with literature data from multiple sources. Using both databases, we also explore the application of COSMO-SAC to solubility predictions in mixed solvents. This work also studies the effects of conformational isomerism on VLE and SLE property prediction. Finally, we compare COSMO-SAC solubility predictions to solubility predictions by the Non-Random Two-Liquid, Segment Activity Coefficient (NRTL-SAC) model. We find UNIFAC is a more accurate method for predicting VLE behavior than the COSMO-SAC model for many of the systems studied, and that COSMO-SAC predicts solute mole fraction in pure solvents with an average root-mean-squared error (log10(xsol)) of 0.74, excluding outliers, which is greater than the RMS error value of 0.43 using the NRTL-SAC model.

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Chavez, Krystle J. "Crystallization of pseudopolymorphic forms of sodium naproxen in mixed solvent systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29759.

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Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Rousseau, Ronald; Committee Member: Meredith, Carson; Committee Member: Prausnitz, Mark; Committee Member: Teja, Amyn; Committee Member: Wilkinson, Angus. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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7

Nzengung, Valentine Asongu. "Organoclays as sorbents for organic contaminants in aqueous and mixed-solvent systems." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/26460.

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8

Penner, S., and H. Lorenz. "From Pure Oxides to Mixed Oxides: Model Systems for Structural and Catalytic Studies." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35049.

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As pure oxides and mixed oxide systems play an ever-increasing role in a variety of research fields ranging from catalysis over electrochemical applications to microelectronics, the present contribution aims at introducing a straightforward concept for the easy and reproducible preparation of well-defined and well-structured thin film model systems both for pure and mixed oxide systems. Exploiting the special structural and surface properties of vacuum-cleaved NaCl (001) growth templates, the concept is exempli-fied for the formation of nano-spheres (Ga2O3), nano-pyramids (In2O3), plates and needles (V2O5) and den-dritic structures (Ga2O3-WO3). Careful tuning of the preparation conditions (substrate temperature, depo-sition rate, oxygen partial pressure or post-annealing temperature) allows the formation of special particle morphologies at much lower substrate temperatures (less than 400°C) than previously and usually applied. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35049

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Cikalo, Maria Gillian. "Separation and quantification of weakly-absorbing and low-concentration analytes by capillary electrophoresis." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321675.

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Das, Bijan. "Physico - chemical investigations on the ion-solvent interactions of some Tetraalkylammonium and common ions in non-aqueous and mixed binary aqueous solvent systems." Thesis, University of North Bengal, 1992. http://hdl.handle.net/123456789/719.

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11

Solorio, Sanchez Francisco Javier. "Soil fertility and nutrient cycling in pure and mixed fodder bank systems using leguminous and non-leguminous shrubs." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/14446.

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Sánchez, F. J. S. "Soil fertility and nutrient cycling in the pure and mixed fodder bank systems using leguminous and non-leguminous shrubs." Thesis, University of Edinburgh, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.662220.

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The overall objective of this thesis work, in the Yucatán peninsula (México), was to establish a system with mixed woody species (leguminous/non-leguminous) to investigate the extent to which they increase nitrogen uptake and growth. The study tested the hypothesis that such mixtures may stimulate of N₂ fixation from the atmosphere and the transfer of N from leguminous to non-leguminous plants. Three woody species were selected: Leucaena leucocephala (legume), Moringa oleifera (non-legume) and Guazuma ulmifolia (non-legume). More than 80% of planted seedlings survived and grew rapidly. Total biomass (fodder) production was 1.9-7.7 ton ha^-1 for monocrops and 6-9 ton ha^-1 for the mixtures. Nitrogen yield in the fodder was higher in the Leucaena+Guazuma mixture (285 kg N ha^-1), followed by Leucaena monocrop and Leucaena+Moringa mixture (244 and 183 kg N ha^-1, respectively). The δ¹⁵ N of samples from non-fixing species ranged from 2.7 to 3.2‰ (mean 3.0 ± 0.45‰). The δ¹⁵ N of L. leucocephala (0.8‰) was significantly lower, indicating that nitrogen fixation occurred in the Leucaena plants. The % Ndfa in the Leucaena mixtures ranged from 58 to 72% while in the Leucaena monocrop it was 69%, at 11 months old. Moringa leaves decomposed most rapidly, followed by Leucaena+Moringa, and, was best described by a double exponential model. The combination of Leucaena+Guazuma decomposed more slowly and pure Leucaena leaves decomposed at an intermediate rate. Over 16 weeks, Leucaena+Moringa released 65-75% of the initial N, Leucaena+Guazuma released 46-63%, and Leucaena leaves alone released, on average, 54% of their N. Lignin+polyphenols and tannins had a strong negative correlation with the rate of nitrogen release. The alteration of the decomposition and N release patterns observed when mixing plant materials of different quality provides good prospects for improving synchrony between N availability and plant N uptake.

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13

蔡曜隆. "Vapor-liquid equilibria(VLE) of binary mixed solvent systems." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/28254880837770085070.

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碩士
明新科技大學
化學工程研究所
96
PGME (propylene glycol monomethyl ether) is widely used as photoresist edge bead remover (EBR) in the liquid crystal display (LCD) manufacturing process. It is important to provide accurate vapor-liquid equilibrium data of binary water + PGME and methanol + PGME systems for the design of separation units. In the experimental part, a static-type VLE meauurement apparatus was utilized at atmosphere pressure. For the water + PGME system, an azeotrope is formed at 83 mol% of water. The vapor-liquid equilibrium data were correlated by the NRTL and the UNIQUAC activity coefficient models. For both systems, the calculated results agree well with the experimental ones, with the mean deviation of vapor phase composition and bubble point temperature being less than 1% and 0.8K, respectively.

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14

Li, Chi-Kwong, and 李繼廣. "Heat capacity of mixed solvent desiccant:SALT/GLYCOL/H2O systems." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/wq9yy6.

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碩士
中原大學
化學工程研究所
92
Abstract The aqueous-organic with salt systems have been recently considered as potential absorbents for liquid desiccants to absorb moisture from air. For rational design of the dehumidifier process, heat capacities of liquid desiccants are required to estimate the correct heating load of dehumidifier equipments. Heat capacities of salt/glycol/H2O systems have been measured in this study over the temperature range 30 to 80 °C with a differential scanning calorimeter. The salts studied are lithium chloride (LiCl) and lithium bromide (LiBr); the glycols considered are diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (T4EG), propylene glycol (PG) and dipropylene glycol (DPG). For each ternary system, four systems of which (4 - 25 mass %) salt mixed with various glycols (50 - 80 mass %) were studied. In addition to ternary systems, the heat capacities of glycols and aqueous glycol solutions were also measured. A Redlich-Kister-type equation for representing excess molar heat capacity was applied to correlate the measured Cp of aqueous glycol solutions. For a total of 175 data points for aqueous glycol solutions, the overall AAD% of the calculations are 1.2 % and 0.4 % for the excess molar heat capacity and the molar heat capacity, respectively. For the salt/glycol/H2O systems, an equation proposed by Söhnel and Novotñy(1988) was used to represent the measured heat capacity data. For salt/glycol/H2O systems, the overall AAD% of the calculations are 0.4 % for 440 data points. The molar heat capacities of salt/glycol/H2O systems presented in this study are, in general, of sufficient accuracy for most engineering-design calculations for design dehumidifier equipments.

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15

Hsu, Shu-Ming, and 許書銘. "A Study on the Solubilities of Electrolyte Mixed Solvent Systems." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/43594507151211380247.

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碩士
國立臺灣科技大學
化學工程系
88
The objective of this study is to investigate the solubility of salt in mixed solvent systems. In the experimental part, a gravimetric analysis apparatus was employed to measure the solubility at 298.15K for nine ternary systems of ethanol-water-NaCl, n-propanol-water-NaCl, i-propanol -water-NaCl,n-butanol-water-NaCl, methanol-water-NaBr, ethanol -water -NaBr, n-propanol-water-NaBr, i-propanol-water-NaBr, and n-butanol -water-NaBr. In the theoretical part, the Chen’s models(1982, 1986) were used to calculate the mean activity coefficients of electrolyte in both binary and ternary electrolyte solutions, respectively. A calculation scheme with Chen’s models is developed to determine the solubilities for the nine ternary systems mentioned above. It was found that the calculated results agree well with the experimental data, with mean absolute deviations ranging from 0.013 to 0.092 for the nine ternary systems studied.

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16

Appaw, Collins. "Rheology and microstructure of cellulose acetate in mixed solvent systems." 2004. http://www.lib.ncsu.edu/theses/available/etd-01102005-140944/unrestricted/etd.pdf.

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17

Haider, Miran. "Geometric Phases In Quantum Systems Of Pure And Mixed State." Thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-48008.

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Note that equations and expressions has been omitted here and is instead presented in the work. This thesis focuses on the geometric phase in pure and mixed quantum states. For the case of a pure quantum state, Berry's adiabatic approach (4.1.10) and Aharonov & Anandan's non-adiabatic generalization of Berry's approach (4.2.8) are included in this work. Mixed quantum state involves Uhlmanns approach (5.1.42), which is used extensively in Section 7 and Sjöqvist's et al. approach (5.2.22), used extensively in Section 6. Sjöqvist's approach states that the Uhlmann phase is an observable and provides the experimental groundworkusing an interferometer.􀀀This was later proven, by Du et al.[45] to reproduce experimental data (Figure 19) on page 56. The Uhlmann phase can be used to observe the behaviour of topological kinks. This was tested on 3 models, the Creutz-ladder, the Majorana chain andthe SSU-model. It is found that the Uhlmann phase is split into two regimes with the dividing parameter being the temperature. This temperature is called the critical temperature, Tc. If the temperatureis is below the critical temperature, the Uhlmann phase yields Π and if thetemperature is above the critical temperature, the Uhlmann phase yields zero.
Observera att ekvationer och andra uttryck har exkluderats här och är presenterade i själva arbetet. Detta examensarbete behandlar geometriska faser i rena och blandade kvanttillsånd. I rena kvanttillstånd finner man Berrys adiabatiska behandling av den geometriska fasen (4.1.10) och Aharonov & Anandan icke-adiabatiska generaliseringav Berry fasen (4.2.8). I det blandade kvanttillstånden har Uhlmann introducerat en förlängning av den geometriska fasen som sträcker sig till det blandadekvanttillstånden (5.1.42), detta finner man i sektion 7. Senare har Sjöqvistet al. introducerat ett alternativ till att angripa geometriska faser (5.2.22) som beskrivs i sektion 6. Sjöqvist konstaterade att Uhlmannfasen är observerbar,i kvantmekanisk mening, och presenterade ett experimentelt upplägg där han visade just detta med hjälp av en interferometer. vilket senare bevisades av Du et al.[45] där de experimentella mätvärdena stämde överens med dem teoertiska (se figur 19 på sidan 56). Uhlmannfasen kan även användas för att observera topologiska "kink"-lösningar. Detta testades för 3 olika modeller; Creutz stege formationen, Majorana kedjan och SSU modellen. Det visade sig att Uhlmannfasen delades up i två regioner och var starkt beroende av temperaturen. Denna temperaturen kallades för den kritiska temperaturen Tc. Om temperaturen liggerunder eller över den kritiska temperaturen får man att Uhlmannfasen ger Π eller 0 respective.

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18

Wu, Ming-Song, and 吳明崧. "A Study on Liquid-Liquid Equilibria of Electrolyte Mixed Solvent Systems." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/45057761185665660469.

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碩士
國立臺灣科技大學
化學工程系
87
The objective of this study is to investigate salt effects on liquid-liquid equilibria (LLE) in mixed solvent systems, including experimental measurements and theoretical predictions. For a temperature range of 15-35oC with an increment of 10oC, the experiments of LLE for binary systems of n-butanol(NBA)- water, iso-butanol(IBA)- water and sec-butanol(SBA)- water and that for ternary system of n-butanol(NBA)- water- NaCl were made and checked with literature data. At a single temperature of 25oC, the LLE data for ternary systems of n-butanol(NBA)- water- KCl, iso-butanol(IBA)- water- KCl and sec-butanol(SBA)- water- KCl were measured in this study. In theoretical simulation, the activity coefficients of solvents were calculated by Tan''s modified Wilson model, combined with vapor pressure model of electrolyte aqueous solutions. The Gibbs-Duhem equation was used to calculate mean activity coefficient of the electrolyte. Based on the scheme of flash calculation, the mole fractions in both phases were predicted without adding new adjustable parameter. It was found that the theoretical simulations for the six cases reported in this study were in good agreement with experimental data.

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19

Lin, Lee Tsung, and 李宗霖. "A Study of Salt Effects on Liquid-Liquid Equilibria for Ternary Mixed Solvent Systems." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/36440300825007317876.

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碩士
國立臺灣科技大學
化學工程系
90
The objective of this study is to investigate salt effects on liquid-liquid equilibria (LLE) of ternary mixed solvent systems. In the experimental part, the LLE measurements of n-butyl acetate－n-butanol－water systems saturated with sodium chloride (potassium chloride or potassium sulfate) were made at 298.15K. It was observed that the salt effect enlarges the area of the two-phase region in the LLE phase diagram. To simulate the salt effects on LLE of ternary mixed solvent systems, a TTK-Wilson activity coefficient model was used to represent the non-idealities in the solution. Based on thermodynamic equilibrium criterion that the activity of each component must be the same in two phases and the concept of mass balance, we can reproduce the LLE data of quaternary mixed-solvent electrolyte systems. No adjustable parameter was needed in the proposed calculation method. It was found that the predicted results were in good agreement with experiment LLE data with a mean deviation less than 0.7﹪for each system.

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20

Hing-Hung, Lin, and 林信宏. "Experimental Investigation on the Shearing Rheology of Dilute Polystyrene in Single and Mixed Solvent Systems." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/87992379043945331634.

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碩士
國立中正大學
化學工程研究所
92
We performed systematical experimental investigations on the shearing rheology of dilute polystyrene in single, highly viscous (DOP) as well as in mixed, highly viscoelastic (DOP plus short-chain polystyrene) solvent systems. Following the usual shear thinning, a pronounced shear thickening followed by a second shear thinning was observed at even higher shear rates for both solvent systems. Significantly, this phenomenon is in excellent accord with the predictions based on dumbbell/bead-spring models that simultaneously consider the effects of hydrodynamic interactions, excluded volume, and finite extensibility, and this appears to be the first time that such a comprehensive rheological feature in shear flows has been experimentally verified. The previous phenomenon, nevertheless, vanishes for the mixed solvent system if there is only a moderate amount of short-chain polystyrene being added; namely, in this case one observed only a simple shear-shinning behavior. This was subsequently ascribed to the poor solvent quality with the addition of short-chain polystyrene, as suggested by earlier low-shear-rate viscometric measurements and light scattering data. This apparent change in solvent quality has been further verified here by the scaling behavior of the relaxation time constants evaluated at the onset of the first shear thinning, as well as by the molecular weight dependence of the measured intrinsic viscosity.

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21

Tsai, Yueh-fu, and 蔡岳甫. "A Modified Setschenow Equation and its application for Liquid-Liquid Equilibria of Mixed Solvent-Electrolyte Systems." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/68217829903096885894.

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碩士
國立臺灣科技大學
化學工程系
88
The objective of this study is to modified Setschenow equation to describe the salt effects on liquid-liquid equilibria (LLE) of mixed solvent systems. In experimental part, the experiments of LLE for binary systems of n-butanol- water, iso-butanol- water and sec-butanol- water and that for ternary system of n-butanol- water- NaCl were made and checked with literature data (De Santis, 1976). The LLE data for ternary systems of n-butanol- water- KCl, iso-butanol- water- KCl and sec-butanol- water- KCl were measured at a single temperature of 298.15K. In the theoretical simulation, the Setscheonw equation was modified and used to calculate the mole fraction of electrolyte in the aqueous phase. The activity coefficients of solvents in mixed solvent-electrolyte systems were calculated by the TTK-Wilson model. Based on the material balance in phase equilibria, the mole fractions in both phases were calculated by using two adjustable parameters. It was found that the theoretical simulations for the twelve systems reported in this study were in good agreement with experimental data. The mean deviation range from 0.004 to 0.015.

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22

Chen, Shang-Yi, and 陳尚誼. "Vapor Pressure, Density, and Viscosity Measurements of Mixed-Solvent Desiccant Systems containing Glycol (DEG/TEG/T4EG/PG/DPG/TPG) + Salt (MgCl2) + Water." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42807792852604569371.

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碩士
中原大學
化學工程研究所
98
In this work, new experimental data for vapor pressure, density, and viscosity of the mixed-solvent desiccant systems containing 40.0 wt% glycol (1) + salt (2) + water (3) were reported for temperatures up to 343.15 K (normal atmospheric condition). The considered glycols were diethylene glycol, triethylene glycol, propylene glycol, tetraethylene gloycol, dipropylene glycol and tripropylene glycol; and the salt is magnesium chloride (wt% = 4.0, 9.0, and 16.0). The vapor pressure, density, and viscosity were presented as functions of temperature and compositions. An empirical equation was used to correlate the temperature and compositional dependence of the density and viscosity data and a model based on the mean spherical approximation for aqueous electrolyte solutions incorporating the pseudo-solvent approach was used to represent the measured vapor pressure as functions of temperature and composition. Satisfactory results were obtained for both density and vapor pressure calculations.

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Dissertations / Theses on the topic 'Pure and mixed solvent systems'

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