Lic.-avh. (sammanfattning) Luleå : Luleå tekniska univ., 2005. / Härtill 4 uppsatser.

Not available / text

Diss. Östersund : Mittuniversitetet, 2008.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (Ph.D.)--Drexel University, 2008. / Includes abstract and vita. Includes bibliographical references (leaves 68-73).

Thesis (M.S.)--University of Akron, Dept. of Mathematics, 2005. / "August, 2005." Title from electronic thesis title page (viewed 11/28/2005) Advisor, Dmitry Golovaty; Faculty Readers, Eric Wright, Curtis B. Clemons; Associate Department Chair, Timothy S. Norfolk; Dean of the College, Charles B. Monroe; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. / Increasing global energy demand as well as air quality concerns have in recent years led to the search for alternative clean fuels to replace fossil fuels. One such alternative is the blending of petrol (gasoline) with ethanol, which has numerous advantages such as ethanol’s ability to act as oxygenate thus reducing the carbon monoxide emissions from the exhaust of internal combustion engines of vehicles. However, the hygroscopic nature of ethanol is a major concern in obtaining a perfectly homogenized petrol-ethanol fuel. This problem has led to the study of ways of homogenizing the petrol-ethanol mixtures. Therefore, this thesis aimed at enhancing the homogenization of petrol-ethanol mixture. Ethanol concentration in ethanol-water mixture plays a key role in enhancing the homogenization of the fuel, thus the bioethanol employed in this study was dehydrated with silica gel using ultrasonication-enhanced adsorption. Afterwards, the dehydrated ethanol was used in studying the homogenization of the fuel blend. Water removal from the bioethanol using ultrasonication-enhanced adsorption shows a 28% increase when compared to the water removal using magnetic-stirring-enhanced adsorption, During ultrasonication-enhanced adsorption, the estimated adsorption enthalpy was – 1 592.82 J/mol (exothermic) and the entropy was -5.44 J/ K mol, indicating a non-ordered loading of water molecules in the adsorption site. In addition, a modified pseudo second order kinetic model given by was proposed for the ultrasonication-enhanced adsorption process. Effect of temperature during ultrasonication-enhanced adsorption was found to be directly proportional to the amplitude and the pulse rate. However, increase in the amplitudes at lower pulse rates resulted in better cavitation, and hence better adsorption. Furthermore, during phase behavior of ethanol-petrol blend, volume fractions of ethanol and petrol were studied with respect to t the depth within the storage container to confirm homogenization of the blend and time of storage. The binodal curve of the ternary diagram shows an increase of homogeneous region indicating an improved interaction between water and petrol. Therefore, the interesting results regarding the homogenization of the fuel blends resulted from using ultrasonication-enhanced blending were very promising, and could be a platform upon which further research efforts could be built on. The concentration distribution in the reactor showed proof of cavitation formation since in both directions, the variation of concentration with both time and distance was found to be oscillatory. On comparing the profiles in both directions, the concentration gradient, diffusion flux, and energy and diffusion rates were found to be higher in the vertical direction compared to the horizontal direction. It was therefore concluded that ultrasonication creates cavitation in the mixture which enhances mass transfer and mixing of ethanol and petrol. The horizontal direction was found to be the diffusion rate limiting step which proposed that the blender should have a larger height to diameter ratio. It is however recommended that further studies be done on the rate-limiting step so as to have actual dimensions of the reactor. Testing of the blended fuel in internal combustion engine showed an optimal performance of this fuel at 60 % volume ethanol content with higher fuel power. The results of fuel consumption and emissions (such as CO2 and CO) trends confirm various reports in literature on the performance of ethanol/petrol blended fuel.

In this dissertation we prove the homogenization for two very different classes of nonlinear partial differential equations and nonlinear elliptic integro-differential equations. The first result covers the homogenization of convex and superlinear Hamilton-Jacobi equations with stationary ergodic dependence in time and space simultaneously. This corresponds to equations of the form: [mathematical equation]. The second class of equations is nonlinear integro-differential equations with periodic coefficients in space. These equations take the form, [mathematical equation]. / text

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Thesis (Ph. D.)--University of Texas at Austin, 2009. / Title from PDF title page (University of Texas Digital Repository, viewed on Sept. 9, 2009). Vita. Includes bibliographical references.