published_or_final_version / Physics / Master / Master of Philosophy

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 80-82). Also available in print.

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, August 2001. / Includes bibliographical references. Also available on the Internet.

No description available.

Thesis (M.Sc.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2008/05/13). Includes bibliographical references.

Cheung Kai Chung Mars = 宇宙學中的題目 / 張啓聰. / Thesis submitted in: September 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 93-95). / Text in English; abstracts in English and Chinese. / Cheung Kai Chung Mars = Yu zhou xue zhong de ti mu / Zhang Qicong. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- "Hubble's Law, the cosmic scale factor and redshift" --- p.1 / Chapter 1.2 --- The Big Bang Model and Cosmic Microwave Background --- p.3 / Chapter 1.3 --- An overview of the universe --- p.4 / Chapter 1.4 --- Current Observation Results and Motivation --- p.6 / Chapter 1.5 --- Review of CMB calculation --- p.7 / Chapter 1.5.1 --- Friedmann Cosmologies --- p.8 / Chapter 1.5.2 --- The Perturbed Robertson-Walker Metric --- p.10 / Chapter 1.5.3 --- Boltzmann Equations --- p.13 / Chapter 1.5.4 --- Perturbative Einstein Equations --- p.16 / Chapter 2 --- Ionization History of The Universe --- p.18 / Chapter 2.1 --- Saha equation --- p.18 / Chapter 2.2 --- Peebles recombination --- p.19 / Chapter 2.3 --- RECFAST --- p.20 / Chapter 3 --- CMB Anisotropics --- p.22 / Chapter 3.1 --- The CMBA spectra --- p.23 / Chapter 3.1.1 --- Tight Coupling Limit --- p.23 / Chapter 3.1.2 --- Free Streaming --- p.25 / Chapter 3.1.3 --- The Anisotropy Spectrum --- p.27 / Chapter 3.1.4 --- CMBFAST --- p.28 / Chapter 4 --- Variation of Fundamental Constant and CMBA spectra --- p.30 / Chapter 4.1 --- The problem of units --- p.31 / Chapter 4.2 --- Modification of CMBFAST and conversion of units --- p.32 / Chapter 4.3 --- The constraints of varying constants using CMBA spectra --- p.35 / Chapter 4.4 --- Physics involved and variation of the spectra --- p.36 / Chapter 4.4.1 --- Effect of Recombination --- p.36 / Chapter 4.4.2 --- Variation of hP --- p.38 / Chapter 4.4.3 --- Variations of e and me --- p.41 / Chapter 4.4.4 --- Variations of g and c --- p.48 / Chapter 4.4.5 --- Constraints on the constants --- p.57 / Chapter 5 --- MCMC and CMBA Spectra --- p.59 / Chapter 5.1 --- Method --- p.60 / Chapter 5.1.1 --- Algorithm --- p.60 / Chapter 5.1.2 --- Check of Convergency --- p.61 / Chapter 5.2 --- Likelihood function --- p.62 / Chapter 5.3 --- Results --- p.66 / Chapter 5.3.1 --- MCMC investigation of varying α in the temperature spectrum --- p.67 / Chapter 5.3.2 --- MCMC investigation of varying α in the polarization spectrum --- p.69 / Chapter 5.3.3 --- MCMC investigation of varying α and cosmological parameters --- p.71 / Chapter 5.3.4 --- Summary --- p.73 / Chapter 6 --- Extra Dimensions and Cosmology --- p.74 / Chapter 6.1 --- A review of KK cosmology --- p.74 / Chapter 6.2 --- Non-flat extra dimension universe --- p.80 / Chapter 6.2.1 --- Close Extra Dimensions and Flat Usual Dimensions --- p.83 / Chapter 6.2.2 --- Open Extra Dimensions and Flat Usual Dimensions --- p.87 / Chapter 6.2.3 --- Summary: Possibility of Extra Dimension(s) --- p.91 / Bibliography --- p.93

Thesis (Ph. D.)--University of New South Wales, 2003. / Also available online.

abstract: The heat transfer enhancements available from expanding the cross-section of a boiling microchannel are explored analytically and experimentally. Evaluation of the literature on critical heat flux in flow boiling and associated pressure drop behavior is presented with predictive critical heat flux (CHF) and pressure drop correlations. An optimum channel configuration allowing maximum CHF while reducing pressure drop is sought. A perturbation of the channel diameter is employed to examine CHF and pressure drop relationships from the literature with the aim of identifying those adequately general and suitable for use in a scenario with an expanding channel. Several CHF criteria are identified which predict an optimizable channel expansion, though many do not. Pressure drop relationships admit improvement with expansion, and no optimum presents itself. The relevant physical phenomena surrounding flow boiling pressure drop are considered, and a balance of dimensionless numbers is presented that may be of qualitative use. The design, fabrication, inspection, and experimental evaluation of four copper microchannel arrays of different channel expansion rates with R-134a refrigerant is presented. Optimum rates of expansion which maximize the critical heat flux are considered at multiple flow rates, and experimental results are presented demonstrating optima. The effect of expansion on the boiling number is considered, and experiments demonstrate that expansion produces a notable increase in the boiling number in the region explored, though no optima are observed. Significant decrease in the pressure drop across the evaporator is observed with the expanding channels, and no optima appear. Discussion of the significance of this finding is presented, along with possible avenues for future work. / Dissertation/Thesis / Ph.D. Mechanical Engineering 2013

The expanding constant is a measure of graph connectivity that is important for certain applications. This paper discusses the mathematical foundations for the construction of Winnie Li's graphs and for the proof that Winnie Li's graphs are Ramanujan. The paper also establishes the implications of the Ramanujan property for the expanding constant. / Master of Science

Effective communication in English between its two billion users (Crystal, 2008), requires comprehension of others’ English and a willingness to accept differences in English. While some studies have attempted to measure the attitudes of Inner Circle (IC) (Kachru, 1985) respondents towards IC Englishes, and other studies have focused on attitudes of Outer Circle (OC) and Expanding Circle (EC) respondents to IC English, there is a dearth of research on OC and EC respondents’ attitudes to non-IC English. Therefore, this study addressed the need for further research focusing on OC respondents’ attitudes to EC users’ English. Specifically, this study of 31 Singaporeans attempted to gain an understanding of their attitudes towards Expanding Circle Accents of English (ECAE). This study drew on direct and indirect approaches in language attitude research, involving a verbal-guise task using semantic differential scales to elicit attitudes to speakers on a range of solidarity and status traits, and interviews. Descriptive statistics derived from mean scores were used for quantitative analysis of the data from the verbal-guise task, while coding procedures were used for qualitative analysis of the interview data. The findings show the respondents displayed predominantly negative attitudes to eight of the eleven ECAE and slightly positive attitudes to three. Phonological features common to the ECAE, notably mispronunciation of particular phonemes and vowels added to consonant clusters, affected the respondents’ attitudes. Moreover, certain prosodic features and the perceived degree of attractiveness and assertiveness affected attitudes to the ECAE. These findings indicate accent can affect listeners’ attitude to speakers. The implications of this study have relevance to the discussions on World Englishes and English as an International Language to the extent that notions of attitude and intelligibility are central to both. Furthermore, the findings suggest attitude might be of greater significance than intelligibility when evaluating others’ English.