Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xiv, 182 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 151-154).

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Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains x, 87 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-82).

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xv, 194 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 180-188).

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Using complexing-agent assisted sol-gel routes, mixed Pd/ceria-alumina and Pd/terbia-ceria-alumina catalysts were prepared. The materials have been characterised by means of ICP-MS, TEM, EDX, XPS, XRD, BET, TPR, TPO and TPD. Catalytic testing was carried out in a temperature programmed mode as well as isothermally, using synthetic exhaust gas mixtures with different air-to-fuel ratios. The obtained results were compared with those of traditionally impregnated Pd/ceria-alumina and PtRh/ceria-alumina. Evaluating the catalysts potential as three-way converters, it has been shown that as a result of the sol-gel preparation chosen, highly homogeneous materials were produced. These had (i) much higher oxygen storage potential (especially at low temperatures, T ≈ 400 - 500K), (ii) improved metal support interactions and (iii) lower CO and propane light-off temperatures (T50%(CO) ≈ 423K, T50%(C3H8) ≈ 593K for R ≥ 1). Under fuel-rich conditions an improved low temperature NO activity was shown for the ceria-containing materials. This was attributed to a ceria-mediated redox mechanism and an improved Pd-ceria interaction for these sol-gel-derived samples. The addition of terbia was found to promote the catalysts propane activity, especially under fuel-rich conditions. The application of the different catalysts as three-way converters has been discussed, with special emphasis on their potential during the cold-start period. In a further set of catalytic experiments, using less complex gas mixtures, a more comprehensive view of the detailed Pd chemistry involved in these new three-way catalysts was obtained.

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M.Ing. / The purpose of this thesis was to gather experimental data of a stainless steel sleeve being formed into a convoluted tube. This convoluted tube, made from stainless steel ASTM 240 type 321 and with a wall thickness of 0,4mm, is the main part of an automotive exhaust bellow. The automotive exhaust bellow fits into a motor vehicle exhaust system. One of the functions of this bellow is to compensate for engine movement. The bellow is also used to damp the engine vibration to the vehicle chassis. Typical failures that occur during the production of a convoluted tube are identified. The data gathered are listed and the forming process, typical conditions and its effects discussed. The actual data and graphs are presented in the annexures at the end of this report. Plasticity theory for shells and cylinders is summarized in Annexure A and the solution of a related problem discussed. Experimental data were used to verify the result of a finite element model. The calculated values of the model compare well with the values of the experimental data. The model must still be developed further and the experimental data can be used to verify this developed model. Possible aspects, related to the forming and life-cycle prediction of an automotive exhaust bellow, that still need to be studied are identified and presented at the end of this report.

A CAT C6.6 turbocharged diesel engine was operated in dual-fuel diesel-hydrogen mode. Hydrogen was inducted into the intake and replaced a portion of the diesel fuel. Hydrogen was added across multiple engine speeds and loads until reaching the knock limit, identified by a threshold on the rate of in-cylinder pressure rise. In-cylinder pressure and emissions data were recorded and compared to diesel-only operation. Up to 74% H2 substitution for diesel fuel was achieved. Hydrogen addition increased thermal efficiency up to 32.4%, increased peak in-cylinder pressure up to 40.0%, increased the maximum rate of pressure rise up to 281%, advanced injection timing up to 13.6°, increased NOx emissions up to 224%, and reduced CO2 emissions up to 47.6%. CO and HC emissions were not significantly affected during dual-fuel operation. At 25% load an operating condition was observed with low NOx and nearly 0 CO2 emissions, which however exhibited unstable combustion.

This paper presents a review of the basic thermal, chemical and radiation balances existing in the atmosphere and discusses the mechanisms by which jet engine exhaust products can disturb these balances. Possible effects of stratospheric pollution on plant and animal life are discussed. Methods for reducing harmful emissions through engine design modifications are outlined and current successful research programs are surveyed. The SST type aircraft is shown to be a greater threat to the environment than conventional jets because of differences in cruise altitudes. It is concluded that due to the existence of several potential environmental problems associated with contamination of the stratosphere, large scale deployment of the SST should be discouraged, at least until current studies are complete and more data is available.