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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Mintz, Christina 05 1900 (has links)
Several studies were done to illustrate the versatillity of the Abraham model in mathematically describing the various solute-solvent interactions found in a wide range of different chemical and biological systems. The first study focused on using the solvation model to construct mathematical correlations describing the minimum inhibitory concentration of organic compounds for growth inhibition towards the three bacterial strains Porphyromonas gingivalis, Selenomonas artemidis, and Streptococcus sobrinus. The next several studies expand the practicallity of the Abraham model by predicting free energies of partition in chemical systems. The free energy studies expand the use of the Abraham model to other temperatures and properties by developing correlations for the enthalpies of solvation of gaseous solutes of various compounds dissolved in water, 1-octanol, hexane, heptane, hexadecane, cyclohexane, benzene, toluene, carbon tetrachloride, chloroform, methanol, ethanol, 1-butanol, propylene carbonate, dimethyl sulfoxide, 1,2-dichloroethane, N,N-dimethylformamide, tert-butanol, dibutyl ether, ethyl acetate, acetonitrile, and acetone. Also, a generic equation for linear alkanes is created for use when individual datasets are small. The prediction of enthalpies of solvation is furthered by modifying the Abraham model so that experimental data measured at different temperatures can be included into a single correlation expression. The temperature dependence is directly included in the model by separating each coefficient into an enthalpic and entropic component. Specifically, the final study describes the effects of temperature on the sorption coefficients of organic gases onto humic acid. The derived predicted values for each research study show a good correlation with experimental values.
12

Fast and accurate macromolecular solvation energy and force computations

Zhao, Wenqi 27 May 2010 (has links)
This thesis reports a comprehensive study of the electrostatic solvation energy computation for macromolecules. In the molecular dynamics (MD) simulations it is important to be able to compute the free energy of the system accurately and efficiently. The solvation energy which is dominated by the electrostatics plays a significant role in the dynamics of macromolecules in solution. The standard way of computing the electrostatic solvation energy is to solve the Poisson-Boltzmann (PB) equations. However, due to the large size of the system, the computation cost of solving the PB equation becomes a bottleneck even for the continuum implicit solvent. The alternative method is the newly developed generalized Born (GB) method which gives a good approximation to the PB calculation if the Born radii are properly computed. The computation of the Born radii is the core computation in the GB method and is laborious. In this thesis we present a novel error-bounded fast surface GB approach which significantly improves the traditional surface GB approaches. An analytic algebraic spline model is built for the geometric model of the molecular surfaces which allows one to do the accurate computation on a coarse mesh. Based on the surface GB theory, we develop an algorithm that computes the Born radii by using the fast summation algorithm at a complexity nearly linear in terms of the number of atoms of the molecule and the number of elements on the mesh of the molecular surface. The algorithm is also extended to the electrostatic forces calculations. Finally we propose a hierarchical coarse grained (CG) model aiming at reducing the number of atoms in a macromolecule while still being able to reproduce the geometry as well as the electrostatic interactions of the atomic model. / text
13

Ab initio studies on the solvation, electronic structures and intracluster reactions in M⁺Ln, with M⁺ = Mg⁺ and Ca⁺, L=H₂O, CH₃OH and NH₃, and n=1-6, and the elimination of a H atom in Na(H₂O)n. / 離子簇合物M⁺Ln, (M⁺ = Mg⁺χχCa⁺ ; L=H₂O, CH₃OH以及NH₃; n=1-6,) 中溶劑化作用, 電子結構, 簇間反應以及 Na(H₂O)n簇合物中H原子離解反應機理的從頭計算研究 / CUHK electronic theses & dissertations collection / Li zi cu he wu M⁺Ln, (M⁺ = Mg⁺ yi ji Ca⁺ ; L=H₂O, CH₃OH yi ji NH₃; n=1-6,) zhong rong ji hua zuo yong, dian zi jie gou, cu jian fan ying yi ji Na(H₂O)n cu he wu zhong H yuan zi li jie fan ying ji li de cong tou ji suan yan jiu

January 2008 (has links)
Chan, Ka Wai. / "May 2008." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 160-169). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.
14

Solvation and solvent exchange studies of metal ions in solution : a nuclear magnetic resonance study

Crea, Joseph January 1976 (has links)
vi, 164 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1977
15

Solvent exchange on the dioxouranium VI ion

Honan, Geoffrey James January 1979 (has links)
75 leaves : graphs ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1980) from the Dept. of Physical and Inorganic Chemistry, University of Adelaide
16

Solvation and solvent exchange studies of metal ions in solution : a nuclear magnetic resonance study.

Crea, Joseph. January 1976 (has links) (PDF)
Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1977.
17

Solvent exchange on the dioxouranium VI ion.

Honan, Geoffrey James. January 1979 (has links) (PDF)
Thesis (Ph.D. 1980) from the Department of Physical and Inorganic Chemistry, University of Adelaide.
18

Solvatochromic investigations of chromatographic processes

Michels, James Joseph, January 1989 (has links)
Thesis (Ph. D.)--University of Florida, 1989. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 231-243).
19

Characterization of Novel Solvents and Absorbents for Chemical Separations

Grubbs, Laura Michelle Sprunger 05 1900 (has links)
Predictive methods have been employed to characterize chemical separation mediums including solvents and absorbents. These studies included creating Abraham solvation parameter models for room-temperature ionic liquids (RTILs) utilizing novel ion-specific and group contribution methodologies, polydimethyl siloxane (PDMS) utilizing standard methodology, and the micelles cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) utilizing a combined experimental setup methodology with indicator variables. These predictive models allows for the characterization of both standard and new chemicals for use in chemical separations including gas chromatography (GC), solid phase microextraction (SPME), and micellar electrokinetic chromatography (MEKC). Gas-to-RTIL and water-to-RTIL predictive models were created with a standard deviation of 0.112 and 0.139 log units, respectively, for the ion-specific model and with a standard deviation of 0.155 and 0.177 log units, respectively, for the group contribution fragment method. Enthalpy of solvation for solutes dissolved into ionic liquids predictive models were created with ion-specific coefficients to within standard deviations of 1.7 kJ/mol. These models allow for the characterization of studied ionic liquids as well as prediction of solute-solvent properties of previously unstudied ionic liquids. Predictive models were created for the logarithm of solute's gas-to-fiber sorption and water-to-fiber sorption coefficient for polydimethyl siloxane for wet and dry conditions. These models were created to standard deviations of 0.198 and 0.122 logunits for gas-to-PDMS wet and dry, respectively, as well as 0.164 and 0.134 log units for water-to-PDMS wet and dry, respectively. These models are particularly useful in solid phase microextraction separations. Micelles were studied to create predictive models of the measured micelle-water partition coefficient as well as models of measured MEKC chromatographic retention factors for CTAB and SDS. The resultant predictive models were created with standard deviations of 0.190 log units for the logarithm of the mole fraction concentration of water-to-CTAB, 0.171 log units for the combined logarithms of both the mole fraction concentration of water-to-CTAB and measured MEKC chromatographic retention factors for CTAB, and 0.153 log units for the combined logarithms of both the mole fraction concentration of water-to-SDS and measured MEKC chromatographic retention factors for SDS.
20

Using the Abraham Solvation Parameter Model to Predict Solute Transfer into Various Mono- and Multi-Functional Organic Solvents

Hart, Erin F 05 1900 (has links)
The Abraham Solvation Parameter Model (ASPM) is a linear, free-energy relationship that can be used to predict various solute properties based on solute-solvent interactions. The ASPM has been used to predict log (K or Cs,organic/Cs,gas) values, as well as log (P or Cs,organic/Cs,water) values for solute transfer into the following organic solvents: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol and 2-butoxyethanol. The derived log (K or Cs,organic/Cs,gas) correlations describe the experimental data to within 0.14 log units (or less). The derived log (P or Cs,organic/Cs,water) correlations describe the experimental data to within 0.16 log units (or less). The ASPM has also been used to predict the enthalpies of solvation of organic solutes dissolved in the following solvents: acetic acid, dimethyl carbonate, diethyl carbonate, 1-butanol, 1-pentanol, 1-hexanol. The derived enthalpy of solvation correlations, using the L solute descriptor, describe the experimental data to within 2.50 log units (or less). The derived enthalpy of solvation correlations, using the V solute descriptor, describe the experimental data to within 3.10 log units (or less). Validation analyses have been performed on several of the correlations; and, as long as the solute descriptors fall within the given ranges as reported, the original correlations show good predictive ability for determining 1) solute transfer into, and 2) enthalpy of solvation for the aforementioned solvents.

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