Thesis (M.S.)--Ohio University, June, 2006. / Title from PDF t.p. Includes bibliographical references (p. 63-71)

I have studied syntectonic veins from shales and coarse calcareous sands of the Ordovician Womble Shale, Benton uplift, Arkansas. All veins are composed of calcite with minor quartz and trace feldspar and dolomite or high-Mg calcite in the coarser veins. All host lithologies have a pressure-solution cleavage, more closely spaced in the fine-grained shale beds. The vein internal fabrics are coarsely to finely fibered, with a strong host-rock grain size control on fiber width. The finest fibers are in veins with shale host and the coarsest in the coarse-grained calcareous sandstone. Fiber aspect ratio is inversely proportional to host grain size; more equant vein grains are found in the veins hosted in the coarse host fraction. Within one outcrop, the δ13C and δ18O compositions of the host lithologies range from 1.5 to -3.0 per mil and 7.5 to -14.0 per mil (VPDB), respectively. By contrast, the δ18O composition of the veins is remarkably constant (-13.5 per mil) among veins of starkly different fabrics. This composition is identical to that of the coarse calcareous sandstone lithology in the outcrop. No cathodoluminescence or stable isotope zoning was observed in the veins. In addition, there were no gradients in Ca or Si in the vicinity of the veins, suggesting either that the host did not contribute these elements or that diffusion was not the rate-limiting step to vein formation. In any case, the wide variety of veins was probably formed from meter-scale migration of fluid derived from local calcite-rich layers in calcareous sandstone.

Conventional stainless steel - water and ceramic fabric composite water heat pipes have been built and tested. The tests have been conducted to compare the performance characteristics between conventional and fabric composite heat pipe radiators for space nuclear power heat rejection systems. The fabric composite concept combines a strong ceramic fabric with a thin metal liner to form a very lightweight heat pipe. The heat pipes tested have used identical, homogeneous fabric wicks and water as the working fluid. One fabric composite heat pipe has been constructed by fitting a braided aluminoborosilicate fabric tube over the outside of the conventional stainless steel heat pipe. A more advanced fabric composite design combines the woven fabric with a 0.25 mm (10 mil) stainless steel tube as the liner, and reduces the mass of the heat pipe by a factor of three. A heat pipe testing facility was designed and built for the purpose of testing various conventional and fabric composite heat pipes. This facility allows the testing of heat pipes in a vacuum, at low temperatures, and can accommodate a variety of heat pipe designs. Instrumentation and computer interfacing provide for continuous monitoring and evaluation of heat pipe performance. Tests show that heat pipe radiator capacity can be significantly enhanced by using the fabric composite design. Tests comparing a conventional heat pipe with fabric composite heat pipes achieved a 100% increase in the emissivity and heat rejection capacity of the radiator. Since the ceramic fabric is strong enough to withstand the internal pressure of the heat pipe, a very thin metal foil can be used to contain the working fluid. The increase in heat rejection capacity, combined with the significant reduction in the heat pipe mass, translates into a substantial savings for space power systems employing fabric composite heat pipe radiators. / Graduation date: 1993

Controlling the orientation and spatial distribution of discontinuous fibers in composite materials enables product properties to be tailored to anticipated use. Electric fields are already (albeit rarely) used to affect alignment in lignocellulosic (LC) fiber composites. The use of magnetic fields has not, however, been suggested or explored; this is apparently because LC fibers are essentially non-magnetic. The approach may offer, however, some considerable advantages, as long as ferromagnetism may be imparted to the fibers. In the present research several fiber modification processes were considered and two, electroless nickel plating and spray application of a coating containing nickel in suspension, were investigated in more depth. The latter was chosen to render highly engineered, elongated wood particles responsive to magnetic fields. Individual treated particles were suspended in viscous, newtonian silicone fluids and their rotation under the influence of a controlled magnetic field was video recorded. The magnetic torque on the particle was, under the above conditions, directly proportional to the fluid viscosity, to the particle's angular velocity and to a characteristic shape constant. The maximum of the specific magnetic torque (magnetic torque divided by the shape constant) was found to reflect the influence of field strength and particle Ni-treatment on rotation. Results were scaled to an arbitrarily chosen viscosity for comparison. The dependencies of the magnetic torque found in the present research compare with those theoretically predicted for ellipsoidal and cylindrical bodies. For field strengths ranging from 0.07T to 0.15T (below magnetic saturation) the magnetic torque increased almost linearly with increasing field strength. Magnetic torque was also found to increase nearly linearly with increasing bulk Ni-concentration (5g/kg - 50g/kg). Rotational motion was sometimes impeded at low field strengths and this was attributed to a permanent magnetic moment obtained by the particle. A coercive field strength of 7600A/m supported this hypothesis. Judiciously switched field polarity increased magnetic torque at small alignment angles. The present research indicates that orienting LC fibers with magnetic fields is possible and promising. To study dynamics of fiber motion in low viscosity fluids, such as air, a different experimental method is necessary; however, dependencies of the magnetic torque found in the present study still hold true. / Graduation date: 1993

No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 153-156). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 153-156). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 83-87). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 83-87). Also available on the Internet.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xii, 112 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 111-112).