Exploring the reasons for student ethnic groupings: The case of Chinese students at the University of Windsor (Ontario).

This study was designed to explore the reasons of the common phenomenon that Mainland Chinese international students on a Canadian university campus are always seen staying within their own culturally homogenous circles with very limited communication with other students from different cultural backgrounds. A qualitative research approach was employed to ascertain the reasons for this phenomenon. Ten Chinese international students from Mainland China studying at the University of Windsor participated in this study. They were interviewed in Mandarin individually over a period of seven weeks, each interview being taped, translated and transcribed. The findings derived from this study include language difficulties, cultural divergence, evaluation criteria, understanding of institutional administration and corresponding response, and the inertia of dependence on compatriot groups. This study adds to existing literature on Chinese international students\u27 sojourn experiences on Canadian university campuses. A portion of the findings of this study lends support to the findings of some previous research on the sojourn life of Chinese international students in Canada. A considerable portion of the findings, however, disputes the conclusions of some existing research on related issues. Some unexpected themes were also generalized through data analysis. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2006 .J54. Source: Masters Abstracts International, Volume: 45-01, page: 0040. Thesis (M.Ed.)--University of Windsor (Canada), 2006

Phase transformations and chemical interactions in materials exposed to high temperatures

Phase transformations and chemical interactions occur in many materials systems exposed to elevated temperatures. In this study, materials exposed to high temperatures in three distinctive applications, have been examined. The first application involves the fabrication of semiconductor-core optical fibers for mid-infrared transmission. Such fibers can be used for chemical sensing, threat detection, and bio-imaging. In this study, germanium-core borosilicate glass cladded fibers were fabricated using rod-in-tube drawing. An analytical model for the deformation and heat transfer in the fiber preform during the high temperature fabrication process was developed. The solidification of the germanium core was experimentally studied using a proxy system of melting ice in a tube. The relative roles of conductive and convective heat transfer in determining the melting mechanism was analyzed. The fabricated fibers were characterized by various electron microscopy based techniques to understand impurity diffusion from the cladding to the core, as well as to study the crystalline quality of the Ge core. The second application involves solid oxide membrane (SOM) based electrolytic production of silicon, where the interaction between the ceramic membrane and the molten salt is the key in determining the lifetime of the membrane. The yttria-stabilized zirconia (YSZ) membrane was found to degrade over time due to chemical interactions with the silica-containing molten oxy-fluoride flux. These interactions led to the formation of a yttria depletion layer in the YSZ in contact with the molten salt. A series of flux compositions were designed to systematically test the correlation between flux optical basicity, yttria activity and YSZ membrane degradation. The results provide a guideline for eliminating membrane degradation during the production of silicon using the SOM electrolysis process. The third application involves molten mixtures of lithium chloride and metallic lithium for metal oxide reduction application. These mixtures exhibit anomalous physical properties that lack a comprehensive explanation. In this study, the structures of bulk molten LiCl and LiCl-Li mixtures were investigated using an in-situ high-energy x-ray diffraction (HEXRD) technique. The structure factors and the pair distribution functions (PDF) of LiCl-Li mixtures were compared with those of pure LiCl. The results suggest Li disperses in LiCl as nano-clusters

Synchronization of dissipative dynamical systems driven by non-Gaussian Lévy noises

Dynamical systems driven by Gaussian noises have been considered extensively in modeling, simulation, and theory. However, complex systems in engineering and science are often subject to non-Gaussian fluctuations or uncertainties. A coupled dynamical system under a class of Lévy noises is considered. After discussing cocycle property, stationary orbits, and random attractors, a synchronization phenomenon is shown to occur, when the drift terms of the coupled system satisfy certain dissipativity and integrability conditions. The synchronization result implies that coupled dynamical systems share a dynamical feature in some asymptotic sense

Multi-scale structure, pasting and digestibility of adlay (Coixlachryma-jobi L.) seed starch

peer-reviewedThe hierarchical structure, pasting and digestibility of adlay seed starch (ASS) were investigated compared with maize starch (MS) and potato starch (PS). ASS exhibited round or polyglonal morphology with apparent pores/channels on the surface. It had a lower amylose content, a looser and more heterogeneous C-type crystalline structure, a higher crystallinity, and a thinner crystalline lamellae. Accordingly, ASS showed a higher slowly digestible starch content combined with less resistant starch fractions, and a decreased pasting temperature, a weakened tendency to retrogradation and an increased pasting stability compared with those of MS and PS. The ASS structure-functionality relationship indicated that the amylose content, double helical orders, crystalline lamellar structure, and surface pinholes should be responsible for ASS specific functionalities including pasting behaviors and in vitro digestibility. ASS showed potential applications in health-promoting foods which required low rearrangement during storage and sustainable energy-providing starch fractions

Ultra small scale high cycle fatigue testing by micro-cantilevers

A new method has been developed for testing high cycle and very high cycle fatigue properties of materials at the micro-scale based on micro-cantilevers. Focused ion beam was employed to cut micro-cantilevers on the surface of a selected grain in a bulk polycrystalline commercial pure Titanium. The bulk specimen was pre-examined by EBSD, so the crystal orientation of all micro-cantilevers were known. The bulk sample with prepared micro-cantilevers was then attached to a high power ultrasonic generator, which can generate mechanical vibration at the frequency 20KHz. The bulk specimen moves with the ultrasonic generator, but the micro-cantilever lags somewhat behind. The resulting deflections generate cyclic stress in the micro-cantilevers. The high vibration frequency means it can easily test into the high cycle and very high cycle regime. The design challenge is to generate enough stress to cause fatigue in these ultra-small specimens because the stress amplitude achieved in vibration is inverse to the cantilever size. Previous finite element model and experiments had shown that the classic micro-cantilever with uniform cross-section [1,2] can only generate stress a few MPa, even with the acceleration was tuned up to 107m/s2. Instead, we designed a new ‘hammer’ shape micro-cantilever as shown in Figure 1a to increase the inertia. This design now generates sufficient stress and enables fatigue testing even in Titanium, which is a challenging material due to the high strength to weight ratio (both high strength and low density require higher acceleration). SN curves in the testing range from 105 to 108 cycles have been obtained for these micro- single crystal Ti samples using a step test protocol. The stress to failure decreases systematically as the number of cycles to failure increases. However, there is strong dependence on the crystal orientation with the fatigue strength at 107 cycles for test pieces cut along the direction being approximately twice that of those cut in the direction. The fatigue strength of micro-fatigue test is significantly lower than the static strength measured on micro-cantilevers of identical size using a nanoindenter. Due to the small specimen size, it is suggested that the results reflect the behavior of fatigue nucleation rather than propagation