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Investigations of water and tracer movement in covered and uncovered unsaturated waste rockMarcoline, Joseph R. 11 1900 (has links)
A better understanding of the hydrogeology of mine waste rock and cover systems is essential for the quantification, prediction and reduction of metals loading to the receiving environment. A series of experiments were conducted on an instrumented intermediate-scale waste rock pile at the Cluff Lake Mine in Saskatchewan to investigate the changes in flow and solute transport within coarse waste rock under three different surface conditions. Following these studies, the waste rock pile was deconstructed, structures were mapped, and samples were collected for physical characterization and pore water extraction. The internal structure of the waste rock pile was more important than the texture and topography under the free-dumped and ripped/leveled surface, while the surface condition was found to be the dominant control on spatial and temporal variability of outflow from the waste rock with the covered surface. Data from a deuterium tracer test, lysimeter outflow, and from TDR probes were used to derive estimates of the maximum and an average pore water velocity through the uncovered and the covered waste rock. An average pore water velocity through the matrix materials of the uncovered waste rock was approximately 1.5 m/yr and maximum preferential flow velocities were as high as 5 m/day. The post-cover pressure wave velocity of 0.1 to 1 m/day is inferred from outflow and TDR data, and average pore water velocities (0.39 m/y and 0.73 m/y) are calculated by the water flux and tracer methods, respectively. The distribution of the tracers in pore water and the internal structure were mapped during a detailed deconstruction of the waste rock pile and attempts were made to link the data to the spatial and temporal patterns of lysimeter outflow. The pore water chloride concentrations and the deuterium values did not provide conclusive data necessary to link the spatial and temporal patterns observed in the lysimeter hydrographs to internal structure; however, it provided insight into the internal flow mechanisms and water residence times.
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Investigating the Molecular Order and Orientation of Cholesterol in Mixtures of Polyunsaturated PhospholipidsBraithwaite, Iain M. 26 August 2011 (has links)
Cholesterol is critical to ensure proper functioning of a membrane. Despite this, the movement of cholesterol within the cell is not fully understood. The molecular order of binary and ternary mixtures of polyunsaturated fatty acids with varying degrees of hy- drocarbon chain unsaturation with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and/or cholesterol was studied using 2H NMR. The introduction of cholesterol into sam- ples of 18:1PC, 18:2PC (unsaturated lipid/DMPC-d54/CHOL, 75:5:20mol%) increased the C-2H bond order by ∼30%. Similar bond ordering was found for 20:4PC and 22:6PC samples, however, they were temperature dependent. A two-phase region (lo-ld) was found for 22:6PC:DMPC-d54/CHOL (75:5:20mol%) for temperatures below 286.7 K. The reorientation axis formed an angle of 78±4◦ with respect to the C3-2H bond vector re- gardless of the lipid. The order parameter of cholesterol was temperature independent, and ranged from 0.69±0.04 to 0.78±0.04 depending on the lipid unsaturation. The re- orientation axis of cholesterol was oriented at ∼25◦ to the bilayer normal.
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High Temperature D2O Isotope Effects on Hydrolysis and Ionization Equilibria in WaterErickson, Kristy M. 23 August 2013 (has links)
This thesis is an investigation of the relative differences of acid ionization constants and ion mobility in D2O versus H2O under hydrothermal conditions, for acetic acid and phosphoric acid. Values of specific conductivity were measured for each acid in H2O and D2O, as well as for a series of strong electrolytes using a high-temperature high-pressure AC conductivity flow cell that was originally designed at the University of Delaware. The Fuoss-Hsai-Fernández-Prini (FHFP) equation was fitted to the experimental values of molar conductivity, Λ, to obtain molar conductivities at infinite dilution, Λo. The molar conductivities at infinite dilution for each acid were used to calculate degrees of dissociation and ionization constants in D2O versus H2O from 298 K to 571 K. Measured values of differences in pKaq in D2O vs H2O, ΔpKaq = [pKaq,D2O – pKaq,H2O], become relatively independent of temperature above 423 K, with values of: ΔpKaq 0.45 for acetic acid and ΔpKaq 0.35 for phosphoric acid. The Density Model was then fitted to the values of pKaq in H2O and D2O to represent their temperature dependence to a precision of ± 0.01 in ΔpKaq.
Comparisons of the molar conductivities and ionic molar conductivities at infinite dilution for the strong electrolytes in H2O and D2O as a function of temperature have also been made, based on Walden’s rule correlations, (λ°•η)D2O / (λ°•η)H2O. Changes in values of (λ°•η)D2O / (λ°•η)H2O as a function of temperature are consistent with a change in the relative hydration behavior of ions, where the effective Stokes’ radii of the ions in D2O versus H2O changes at temperatures above ~ 450 K. Changes in values of
(λ°•η)D2O / (λ°•η)H2O for D+/H+ and OD-/OH- suggest that proton hopping “Grotthuss” mechanisms become more efficient in D2O versus H2O with increasing temperature. / University Network of Excellence in Nuclear Engineering, Ontario Power Generation Ltd, Natural Science and Engineering Research
Council of Canada
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Investigation of fatty acid and cholesterol synthesis using stable isotopes in type 1 diabetes, liver failure, islet and liver transplant, and effect of dietary interventionLambert, Jennifer E. Unknown Date
No description available.
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Photodisintegration of the Deuteron at 18 MeV using Linearly Polarized Photons2014 July 1900 (has links)
This thesis reports the: cross section, parameterized differential cross section, and analyzing power (a.k.a. the photon asymmetry), for neutron production via the photodisintegration of the unpolarized deuteron at 18 MeV using linearly polarized photons.
The data were collected in October 2010 using the High Intensity Gamma Source at the Duke Free-Electron Laser Laboratory located at Duke University in Durham, North Carolina. The ejectile neutrons from the photodisintegration reaction were measured using the Blowfish detector array: a spherical array of 88 BC-505 liquid organic scintillator cells which cover approximately pi steradians.
The initial goal of our experiment was to perform tests on the detector characteristics and check a few potential sources of systematic error, and so uncontaminated experimental runs were only taken with the remaining beam-time. Our data are therefore not optimized for precision, and so presented a number of data analysis challenges. This thesis delineates the challenges and respective solutions.
Contrary to earlier results near deuteron binding energy threshold, we see reasonable agreement with a theoretical calculation based on retarded one meson exchange with empirical cutoffs in the propagators, including: off-shell corrections, relativistic corrections and the Delta isobar degree-of-freedom. Our results show similar agreement to theory as previous experiments at 14 and 16 MeV, although we see no target length dependence: such has been observed at 20 MeV.
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Investigation of fatty acid and cholesterol synthesis using stable isotopes in type 1 diabetes, liver failure, islet and liver transplant, and effect of dietary interventionLambert, Jennifer E. 06 1900 (has links)
Elevated plasma lipids are risk factors for cardiovascular disease (CVD). In certain conditions plasma lipids are normal yet individuals experience increased morbidity. Type 1 diabetes (T1D) is associated with elevated CVD despite normal lipids, while in liver failure low plasma lipids may indicate increasing hepatic damage. Plasma lipids can therefore belie underlying dysregulated lipid metabolism. Islet (ITx) or liver (LTx) transplants represent therapies for T1D and liver failure, respectively, but are associated with altered lipid metabolism attributed to immunosuppressive medications; however, causative mechanisms are unknown. Partial success of dietary therapy in post-transplant patients may be due to interventions limited in scope. Regulation of plasma lipids involve absorption, synthesis, and clearance. These studies examined lipogenesis and cholesterol synthesis using deuterium incorporation. In brittle T1D lipogenesis and cholesterol synthesis were similar to healthy controls; however hepatic lipogenesis and cholesterol synthesis tended to be lower in T1D compared to matched control subjects. Plasma cholesterol was lower and triglyceride similar in liver failure patients compared to controls. Lipogenesis was higher while cholesterol synthesis was lower in liver failure compared to controls. Disturbances in lipid synthesis may be influenced by underlying disease, such as hepatitis C. In ITx and LTx lipogenesis was lower whereas cholesterol synthesis was similar compared to controls. Lipid synthesis is therefore unlikely to contribute to post-transplant hyperlipidemia, inviting investigation of other mechanisms. Dietary intervention emphasizing fish oil, phytosterols, soy, fibers, and almonds lowered plasma lipids in controls but had mixed effects in transplant subjects. Reduction in plasma lipids occurred in transplant patients with higher baseline lipids, suggesting this intervention may be successful in hyperlipidemic patients; however the potential of this diet intervention requires further study in hyperlipidemic patients. Diet intervention lowered lipogenesis but did not significantly change 24h cholesterol synthesis in controls. Diet did not change 24h lipogenesis or cholesterol synthesis in transplant subjects. Plasma lipid response to dietary therapy was related to baseline cholesterol synthesis and to dietary compliance in transplant subjects. Further study is required to determine if cholesterol synthesis is predictive of response to diet. / Nutrition and Metabolism
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Investigations of water and tracer movement in covered and uncovered unsaturated waste rockMarcoline, Joseph R. 11 1900 (has links)
A better understanding of the hydrogeology of mine waste rock and cover systems is essential for the quantification, prediction and reduction of metals loading to the receiving environment. A series of experiments were conducted on an instrumented intermediate-scale waste rock pile at the Cluff Lake Mine in Saskatchewan to investigate the changes in flow and solute transport within coarse waste rock under three different surface conditions. Following these studies, the waste rock pile was deconstructed, structures were mapped, and samples were collected for physical characterization and pore water extraction. The internal structure of the waste rock pile was more important than the texture and topography under the free-dumped and ripped/leveled surface, while the surface condition was found to be the dominant control on spatial and temporal variability of outflow from the waste rock with the covered surface. Data from a deuterium tracer test, lysimeter outflow, and from TDR probes were used to derive estimates of the maximum and an average pore water velocity through the uncovered and the covered waste rock. An average pore water velocity through the matrix materials of the uncovered waste rock was approximately 1.5 m/yr and maximum preferential flow velocities were as high as 5 m/day. The post-cover pressure wave velocity of 0.1 to 1 m/day is inferred from outflow and TDR data, and average pore water velocities (0.39 m/y and 0.73 m/y) are calculated by the water flux and tracer methods, respectively. The distribution of the tracers in pore water and the internal structure were mapped during a detailed deconstruction of the waste rock pile and attempts were made to link the data to the spatial and temporal patterns of lysimeter outflow. The pore water chloride concentrations and the deuterium values did not provide conclusive data necessary to link the spatial and temporal patterns observed in the lysimeter hydrographs to internal structure; however, it provided insight into the internal flow mechanisms and water residence times.
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Deuterium isotopomers as a tool in environmental research /Betson, Tatiana, January 2006 (has links)
Diss. (sammanfattning) Umeå : Univ., 2006. / Härtill 4 uppsatser.
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Space independent fusion reactor kinetics submitted as a Master's project under NE 599 /May, Randall S. Akcasu, Ziyaeddin A. January 1971 (has links)
Thesis (M.S.)--University of Michigan, 1971.
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Solvent ordering near cyclohexadienyl type radicals, and ferroelectric ordering of pyridinium perchlorateVujosevic, Danilo. January 2007 (has links)
Stuttgart, Univ., Diss., 2007.
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