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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.
161

Walking Nietzsche's tightrope: a thesis for no one

Dotson, Paul Robert 29 September 2009 (has links)
The philosophy of Friedrich Nietzsche is thought-provoking and enigmatic. This work is an exploration of three of the bulwarks of Nietzsche's philosophy and an attempt to trace their political implications. Analyses of Nietzsche’s concepts of the will to power, eternal return, and the Übermensch are presented in an effort to build a coherent vision of Nietzsche’s work. The will to power has been interpreted in many ways, and in this text I make the case that it is a drive for self-cultivation and finding one’s own direction in life. Eternal return is presented as a mythic idea which Nietzsche thought would spur people to live each moment as if they wished it would recur eternally, rather than judging their actions by future promises or past glories. The Übermensch is the Nietzschean individual who believes in eternal return and engages in self-cultivation through the will to power. There are interesting political implications which follow from this philosophical framework, which I discuss in the final chapter. Based on the analysis of the three concepts mentioned above, I argue that Nietzsche thought societal problems were never cured or even lessened by politics or any political theory. / Master of Arts
162

Masonry heater performance evaluation: efficiency, emissions, and thermal modeling

Gutierrez, Mauricio F. 06 October 2009 (has links)
Two stack loss efficiency measurement methods, the Total Combustible Carbon (TCC) and Combustibles Meter (CM) methods, have been modified for use on masonry heaters. The applicability of the two methods has been verified with 6 tests on two masonry heaters. Each test starts with a cold heater and requires five firings to achieve two different burn rates. The efficiencies calculated for each firing are weighted according to burn rate following EPA Method 28 for wood heaters. The TCC Method uses carbon balances to calculate the chemical energy loss and the dry stack gas mass for calculation of sensible energy loss. The sensible loss that occurs during the off-period, when combustion of wood has stopped, is measured directly by injecting carbon dioxide in the stack and using it as a tracer gas to measure stack flow rate. In both methods the latent energy loss is calculated from wood moisture content and hydrogen content. The CM Method measures losses more directly and is considered the reference method in this work. The chemical energy loss is measured using a flame combustibles meter. The stack flow rate, which is used for the calculation of sensible loss, is measured directly using carbon dioxide tracer gas during both the on and off periods of the appliance. The overall average efficiencies measured by the two methods, in 5 tests on two different appliances, differed by a maximum of 1.7 percentage points of the fuel energy input. On the average they differed by about 1 percentage point. The results of a one-dimensional finite-difference model of the heat exchanger of one of the tested masonry heaters is compared against thermocouple-measured temperatures. For the 3 tests performed the model predicts the measured temperatures to within 12% during the first half of a firing cycle when the burn rate is high, and to within 5% during the second half of the cycle when the burn rate is low. / Master of Science
163

Optimization of the bottom plate of a ground-supported liquid storage tank

Zmerli, Mustapha 05 December 2009 (has links)
Several tanks have failed due to intolerable differential settlements, causing major problems in most cases. The objective of this study is to optimize the bottom plate of the tank so that the differential settlements are reduced to a minimum. Circular plates on an elastic half-space are investigated and the improvements in differential settlements are reported. The plates are loaded by a uniform pressure, and the effects of edge loads, edge moments, and elastic restraints at the edge are considered. A plate with two annular segments having fixed radii is investigated for optimal thicknesses. The plate is also optimized by varying both the radii and the thicknesses. Another plate with three segments is studied, varying the radii and the thicknesses. In all these cases, the plates are examined for a wide range of relative stiffnesses. For a specific relative stiffness, a plate with ten segments of fixed radii is studied. Also, the contact stress distribution is investigated for the case of the three-segment plate. During the study, the results are compared to a uniform plate. As an outcome, the differential settlement is significantly improved compared to the widely used uniform plate. / Master of Science
164

Development models of the Philippines

Gaabucayan, Ma. Sheila A. 23 December 2009 (has links)
This purpose of this study is to construct computer models that can simulate national and regional development thus provide policy makers with a tool for policy experiments. This paper describes two models developed using the system dynamics methodology. The Development Model of the Philippines (DHP) is a national model organized into seven sectors: (1) Industrial Sector, (2) Environmental Sector, (3) Infrastructure Sector, (4) Social Development, (5) Demographic Sector, (6) Agriculture Sector, and (7) Employment Sector. Six policy experiments were performed using DHP: (1) Government Support of Agriculture Policy, (2) Government Allocation to Social Services, (3) Industrial Development Policy, (4) Infrastructure,(5) Environmental Protection Policy, and (6) Zoning Policy. The second model described in this study, called BUKID (from the filipino word for 'countryside'), is a multisectoral regional development model embodying the dynamics of rural-urban dependency with emphasis on the impact of investment on rice and corn farmers. It is composed of the following sectors: ( 1 ) Agriculture, (2 ) Industrial, ( 3 ) Demographic, and (4) Transportation. Four policy strategies that may be evaluated using BUKID are described herein. These are: (1) Land Reform, (2) Feeder Road Construction, (3) Crop Production Policy, and (4) Promotion of Agro-based Industries. / Master of Science
165

Design of, and initial experiments with, a MIMO plate control testbed

Cole, Daniel G. 06 October 2009 (has links)
This work discusses the design of, and initial experiments with, a MIMO plate control testbed. This structure will be used as a development and standard comparison site for AVC and ASAC and is an extension of previous SIMO control investigations which used accelerometers and shakers. This portion of the development process of the MIMO plate control testbed is concerned with actuator and sensor materials and architecture, modeling approaches and requirements, and initial control experiments. The piezoelectric sensors and actuators are arranged on the plate to control the first five vibration modes. The sensors measure plate positions using a high impedance signal conditioning amplifier. The sixteen-channel design implements a band-pass filter to eliminate low- and high-frequency noise. The power amplification scheme chosen for the actuators uses low-gain amplifiers (~2.5 V/V) in series with a transformer (24:1) to deliver high voltages (up to 150 V) to the actuators. Low-pass smoothing filters (200 Hz cutoff) were added on the control inputs to reduce the high frequency content of the zero-order-held digital control signal. Initial methods for system identification of piezostructures are presented. Parametric frequency response approaches (modal analysis) were used and the model achieved is compared with measured data and purely analytic models. The empirical model was used in initial SIMO control experiments to demonstrate the testbed closed-loop performance. A LQG controller was implemented and produced 6 dB of suppression for the second mode for a 110 Hz disturbance. / Master of Science
166

Synthesis of an activated difluorotetraketone monomer via Reissert chemistry

Brumfield, Kimberly K. 11 May 2010 (has links)
The chemistry of Reissert compounds has been utilized to synthesize an activated difluorotetraketone monomer, 1 A-bis { 1-[ 4-(p-fluorobenzoyl)isoquinoly ] carbonyl } benzene (18). Two synthetic routes were explored in an attempt to find an efficient means of preparation. These routes entail preparation via a dibenzylic bis(isoquinoline) and a diketone bis(isoquinoline) system. These compounds were converted to their corresponding Reissert compounds. Reaction of the anion of the dibenzylic Reissert compound with p-fluorobenzaldehyde, followed by oxidation of both benzylic sites has produced the novel difluorotetraketone monomer. In addition, rearrangement of the dike tone Reissert compound has produced the novel difluorotetraketone monomer. This monomer offers a route to a novel family of poly(heteroarylene ethers). / Master of Science
167

Evaluation of the VPI & SU fluid film bearing test rig

Swanson, Erik Evan 12 September 2009 (has links)
The design of advanced, state-of-the-art turbomachinery requires accurate analytical tools for predicting rotor response and evaluating stability. One of the required tools is a reliable analytical code for predicting the performance of fluid-film bearings. This work presents an initial evaluation of a test rig for verifying such codes. This presentation includes background information on the techniques and terminology of fluid-film bearing analysis and two basic approaches to experimental evaluation of fluid-film bearings. To establish one such code, NPADVT, as a useful tool for evaluating the performance of the test rig, comparisons between six published, experimental evaluations of fluid-film bearings for static characteristics and the corresponding NPADVT analysis are presented. With the code thus anchored, and its limits established, experimental data generated with the test rig are compared to appropriate analyses and the test rig shown to be essentially functional. Finally, experimental static results for a pocket bearing generated with the test rig are presented and compared with analysis. / Master of Science
168

Production of hybrid striped bass (Morone chrysops x Morone saxatilis) in a recirculating aquaculture system

Nunley, Chad E. 22 August 2009 (has links)
TRIAL 1 A preliminary study was conducted to evaluate growth, survival and feed conversion of reciprocal cross hybrid striped bass (<i>Morone chrysops</i> female x <i>Morone saxatilis</i> male) cultured in pilot-scale recirculating aquaculture systems. Hybrid striped bass were stocked in nine 12,500 liter recirculating systems at a mean density of 149 fish/m³. Mean weight at stocking was 40.6 g. Overall survival averaged 72.5%. One system experienced 100% mortality due to the loss of the recirculating pump. Three systems experienced significant mortalities in the middle of the study due to unknown causes. Survival was high, averaging 93.5%, in the remaining systems. Mean daily growth rate of 1 g per day and mean feed conversion of 1.67 compared favorably with that reported in the literature for hybrid striped bass. Slow start-up of new biofilters led to a restricted feeding regime and limited growth. Mean fish weight at harvest averaged 262.1 g with total biomass in the tank averaging 452.57 kg. The recirculating system maintained water quality within ranges adequate for good growth, but the stocking density may have surpassed the systems maximum capacity. TRIAL 2 Results from Trial 1 indicated a need to reduce stocking densities. In Trial 2, three densities of reciprocal cross hybrid striped bass, high (144 fish/m³), medium (72 fish /m³) and low (36 fish/m³) were stocked in eight pilot-scale recirculating systems (12,500 L) and evaluated over 224 days. At stocking, mean weights averaged 34.9, 50.8, and 43.4 g for the high, medium and low treatments, respectively. Fish were hand fed a high protein (44%) floating pellet twice daily. Final weights averaged 412.2 g, 541.1 g, and 676.1 g in the high, medium and low density treatments, respectively. No difference in mean weights were detected between the high and medium densities, but those in the low density were significantly greater (p < 0.05) than the medium and high densities. Total biomass was significantly different (p < 0.05) between treatments at the end of the study and inversely related to mean weight gain, averaging 733.8 kg in the high, 483.3 kg in the medium, and 297.9 kg in the low density treatments. The water quality parameters measured were similar among treatments and adequate for good growth. Feed conversions averaged 1.43 and were not significantly different between treatments. Survival averaged greater than 95% in all treatments. The results of this study demonstrated that hybrid striped bass can grow from fingerling to market size in 224 days in recirculating systems at densities of 36 and 72 fish/m³. If environmental conditions are adequately maintained, it is anticipated that higher densities could reach market size in the same time period. Overall results indicate that hybrid striped bass have good potential for culture in recirculating aquaculture systems. / Master of Science
169

Weighted sensitivity optical fiber sensors: theory and applications

Fogg, Brian Russell 10 October 2009 (has links)
The polarimetric behavior of conventional dual mode, elliptical-core, optical fiber sensors is investigated. To compliment the experimental results, a novel linearly polarized modal analysis of elliptical-core geometries is performed. The method numerically finds solutions of a waveguide equation described by Mathieu differential equations. To move beyond conventional dual mode fiber sensing applications, selected placement of the dual mode fiber endpoints upon a flexible structure is investigated. Modal filtering behavior will result if the endpoints are chosen to span two antinodes of the underlying structure. To truly achieve signal processing capabilities, spatially weighting the sensitivity of the sensor becomes necessary. Experimental results are described and future applications are proposed. / Master of Science
170

A dual-junction thermocouple probe for compensated temperature measurement in reacting flows

Scattergood, Thomas R. 12 September 2009 (has links)
This project was conducted in an effort to develop an inexpensive and reliable means of acquiring spatially and temporally resolved temperature data in turbulent reacting flows. Such a system would allow for increased understanding of turbulent reacting flows without the need for a costly and complex optical system. The system under study uses the responses of two thermocouples of different sizes placed in close proximity in order to determine instantaneous temperatures. This is in contrast to previous work in which compensation is performed on a single thermocouple junction in order to correct for the error caused by its heat capacity. The compensation technique that was developed did not require knowledge of the physical properties of the flow or the physical properties of the thermocouples. It did require the measured junction temperatures, the temperature gradients, and the ratio of the time constants of each thermocouple, which is related to the ratio of the diameters of the two junctions. Computer models were used to demonstrate the compensation technique itself and were used to show how this method is affected by such factors as diameter ratio, noise, size of the junctions, and the digital resolution of the voltage-to-temperature conversion. Dual junction probes were constructed and tested in non-reactive and reactive environments. Non-reactive experiments were used to calibrate the probe diameter ratio and compensation of thermocouples that were heated with a laser and then cooled appeared successful, with errors of 5% or less in the corrected temperatures. Data was taken in the exhaust duct of a step combustor and the compensated temperatures from this turbulent, combusting environment appeared realistic. Some non-physical temperatures were produced which resulted in the elimination of around 37% of the total data set. Non-physical temperatures were inconclusively attributed to a combination of spatial separation of the thermocouples, conduction losses, and to poor response of the junctions due to their size and heat capacity. Best results were obtained when the thermocouples were exposed to a non-reacting jet of heated air. In this situation, the response amplitude of the thermocouples was relatively large and the response frequency relatively low in comparison to the reacting experiments. In this case, the corrected temperature curve appeared to be physically realistic and properly in phase with the thermocouple signals. Around 10% of the data was discarded using error elimination techniques. It was decided that a workable system which was limited by the size and spatial separation of the thermocouples had been achieved. / Master of Science

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