Several feeding-related factors can affect taste sensitivity or preferences and therefore may be part of a homeostatic regulatory mechanism. Cholecystokinin (CCK), a hormone which reduces food intake in several species, has also been postulated to interact with the orosensory characteristics of food. To test this hypothesis, the effects of CCK-8 and food deprivation on the short-term intakes of water, sucrose solutions (0.05 to 1.0 M), and saline solutions (0.05 and 0.15 M) were determined. In most cases, CCK (2 μg/kg) reduced sucrose intake when measured either as the amount consumed or the number of licks in a short period (nine minutes). Additionally, CCK reduced the intake of 0.15 M NaCl in satiated rats and water intake in both hungry and satiated rats. Rats usually consumed more sucrose when hungry than when satiated or fed ad libitum; CCK-induced suppression of intake, however, was generally greater in the satiated or ad libitum conditions than in the hungry condition. There was no systematic effect of sucrose concentration on the amount of CCK-induced suppression of intake, which suggests that CCK regulates rather than interferes with ingestion. To determine whether the CCK-induced suppression is due to a change in the peripheral taste signal, the integrated chorda tympani responses to sucrose and NaCl tastes were recorded in rats anesthetized with either urethane, Innovar-Vet, or a combination of urethane and alpha-chloralose. The only significant effect of CCK was the slight increase in the initial response to 0.3 M sucrose after the infusion of a total of 10 μg of CCK-8 into rats anesthetized with Innovar-Vet. In general, therefore, the effect of CCK on sucrose intake does not appear to be due to a peripheral taste change; an analysis of single taste fibers, however, would be more conclusive. An examination of the effects of CCK on central gustatory and reward areas might yet provide a mechanism for the CCK effect on taste-motivated ingestion.

The labyrinth seal is widely used in turbomachinery to minimize or control leakage between areas of different pressure. The present investigation numerically explored the effect of damage and wear of the labyrinth seal on the turbomachinery flow and temperature fields. Specifically, this work investigated: (1) the effect of rubgroove downstream wall angle on seal leakage, (2) the effect of tooth bending damage on the leakage, (3) the effect of tooth "€œmushrooming"€ damage on seal leakage, and (4) the effect of rub-groove axial position and wall angle on gas turbine ingress heating. To facilitate grid generation, an unstructured grid generator named OpenCFD was also developed. The grid generator is written in C++ and generates hybrid grids consisting primarily of Cartesian cells. This investigation of labyrinth seal damage and wear was conducted using the Reynolds averaged Navier-Stokes equations (RANS) to simulate the flows. The high- Reynolds k - Model and the standard wall function were used to model the turbulence. STAR-CD was used to solve the equations, and the grids were generated using the new code OpenCFD. It was found that the damage and wear of the labyrinth seal have a significant effect on the leakage and temperature field, as well as on the flow pattern. The leakage increases significantly faster than the operating clearance increase from the wear. Further, the specific seal configuration resulting from the damage and wear was found to be important. For example, for pure-bending cases, it was found that the bending curvature and the percentage of tooth length that is bent are important, and that the mushroom radius and tooth bending are important for the mushrooming damage cases. When an abradable labyrinth seal was applied to a very large gas turbine wheelspace cavity, it was found that the rub-groove axial position, and to a smaller degree, rub-groove wall angle, alter the magnitude and distribution of the fluid temperature.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 154-176). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 154-176). Also available on the Internet.

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Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 224-275.

Thesis (M.S.)--Ohio University, November, 2004. / Includes bibliographical references (p. 77-97)

Thesis (Honors)--College of William and Mary, 2010. / Includes bibliographical references (leaves 34-36). Also available online.

Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 77-97)