Thesis (doctoral)--University of Jyväskylä, 1997. / Extra t.p. with thesis statement inserted. Includes bibliographical references (p. [184]-199).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 103-105). Also available via the Internet.

Thesis (M.S.)--California Polytechnic State University, 2010. / Title from PDF title page; viewed on June 10, 2010. Major professor: Taufik, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Electrical Engineering." "May 2010." Includes bibliographical references (p. 67-69).

Bachelor-Arbeit Univ. St. Gallen, 2005.

Thesis (doctoral)--University of Jyväskylä, 1997. / Extra t.p. with thesis statement inserted. Includes bibliographical references (p. [184]-199).

Thesis submitted in fulfilment of the requirements for the Degree Master of Technology: Chemical Engineering in the Faculty Of Engineering at the Cape Peninsula University of Technology / It is known when synthesising nanomaterial on laboratory scale, a variation in a single synthesis parameter may alter the product. Numerous synthesis techniques have been employed in the synthesis of titanium dioxide with varying phase, size and shape. It was found that changes in the phase directly affect their properties and application, such as treating of textile wastewater by photodegradation. However, when synthesising nanoparticles, changes to any reaction parameters and/or kinetics can have a desirable or undesirable effect on titanium dioxide nanoparticles. There is therefore a need to understand how HCl acid concentration (homogeneous catalyst) and shortened gel formation duration affect synthesis of TiO2 nanoparticles and photocatalytic properties. A sol-gel followed by hydrothermal treatment was employed to synthesise 2.8 grams of titanium dioxide nanorods for the duration of 96 hours, initially. A systematic study was conducted to exploit reaction kinetics by varying HCl acid concentration (3, 4, 5 molar), water feed for TiO2 gel formation (72, 24, 12 hours), and hydrothermal treatment time for the transformation of gel to crystalline TiO2 (1–20 hours). The photocatalytic activity of synthesised TiO2 nanoparticle was evaluated, when irradiated with a UV-C bulb to degrade an industrial textile dye, methylene blue. Systematic studies were successful in identifying the effects HCl acid concentration, gel formation time and lengthened hydrothermal treatment time have on TiO2 nanoparticles’ phase, size and shape. Increased HCl concentrations for shortened gel formation times resulted in mixed phases of TiO2, decreases in particle size and particle shape deformed from nanorods. Increased photocatalytic activity was found for a decrease in the rutile and increase in the brookite phase percentage, but this plateaued after 42% brookite phase. Furthermore, lengthened hydrothermal treatment assisted in phase transformation of particles synthesised at shortened gel formation times for high HCl acid concentrations. Pure rutile TiO2 was synthesised at a sixth of the initial synthesis time. Furthermore, the effects of changes in nanoparticles on the photocatalytic activity was discussed. Moreover, exploiting reaction kinetics resulted in the synthesis of a more efficient photocatalytically active TiO2 nanoparticle sample at shortened synthesis time.

M.Ing. (Electrical & Electronic Engineering) / Please refer to full text to view abstract

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In spoken French, the phonological processes of liaison and resyllabification can render word and syllable boundaries ambiguous. In the case of liaison, for example, the /n/ in the masculine indefinite article un [oẽ] is normally latent, but when followed by a vowel-initial word the /n/ surfaces and is resyllabified as the onset of that word. Thus, the phrases un air ‘a melody’ and un nerf ‘a nerve’ are produced with identical phonemic content and syllable boundaries [oẽ.nɛʁ]). Some research has suggested that speakers of French give listeners cues to word boundaries by varying the duration of consonants that surface in liaison environments relative to consonants produced word-initially. Production studies (e.g. Wauquier-Gravelines 1996; Spinelli et al. 2003) have demonstrated that liaison consonants (e.g. /n/ in un air) are significantly shorter than the same consonant in initial position (e.g. /n/ in un nerf). Studies on the perception of spoken French have suggested that listeners exploit these durational differences in the segmentation of running speech (e.g. Gaskell et al. 2002; Spinelli et al. 2003), though no study to date has tested this hypothesis directly. The current study employs a direct test of the exploitation of duration as a segmentation cue by manipulating this single acoustic factor while holding all other factors constant. Thirty-six native speakers of French and 54 adult learners of French as a second language (L2) were tested on both an AX discrimination task and a forced-choice identification task which employed stimuli in which the durations of pivotal consonants (e.g. /n/ in [oẽ.nɛʁ]) were instrumentally shortened and lengthened. The results suggest that duration alone can indeed modulate the lexical interpretation of sequences rendered sequences in spoken French. Shortened stimuli elicited a significantly larger proportion of vowel-initial (liaison) responses, while lengthened stimuli elicited a significantly larger proportion of consonant-initial responses, indicating that both native and (advanced) non-native speakers are indeed sensitive to this acoustic cue. These results add to a growing body of work demonstrating that listeners use extremely fined-grained acoustic detail to modulate lexical access (e.g. Salverda et al. 2003; Shatzman & McQueen 2006). In addition, the current results have manifest ramifications for study of the upper limits of L2 acquisition and the plasticity of the adult perceptual system in that they show evidence nativelike sensitivity to non-contrastive phonological variation. / text

No description available.