Buildings have significant and complex impacts both in their construction and in their use. Green building rating systems have been developed and promoted in more economically-advanced countries to offer guidelines to reduce negative impacts and to promote sustainable practices of building construction and operations. The green building rating system called Leadership in Energy and Environmental Design (LEED), established in 1995 by the U.S. Green Building Council, is increasingly accepted as a meaningful measure for sustainability in building design and construction in the U.S. The Building Research Establishment Environmental Assessment Method (BREEAM) rating system in the U.K. and the Green Star rating system in Australia serve similar roles in their respective areas. How applicable are these green building rating systems to countries with different building cultures, climates and economic parameters? The research is based on my work as an architect and participant observer using case study analysis of several buildings that I have designed in Madagascar and Tanzania. The research indicates that several important aspects particular to the developing country contexts of Madagascar and Tanzania — such as labor and security - are not addressed by existing green building rating systems that have been developed in the context of more economically-advanced countries. Such rating systems typically give prominence to aspects such as mechanical systems and indoor air quality that are of limited relevance to the contexts of Madagascar and Tanzania. The results have implications for the development of green building rating systems that address the particular contexts of developing countries. By taking into account parameters such as those found in Madagascar and Tanzania and similar developing countries, the benefits of using an accepted measure of sustainability can be more effectively extended to the developing country sector. / Ph. D.

This study tests an aspect of the environmental theory of Peter Huber outlined in his book <i>Hard Green: Saving the Environment from the Environmentalists: A Conservative Manifesto</i> (1999). Huber's thesis is that wealth leads to environmental conservation in two ways: 1) that wealthy nations develop and implement technologies to maximize the efficiency of land use, and 2) that wealthy individuals pour their wealth into the conservation of nature. Using secondary data analysis, I test the first national-level hypothesis with regressions of the variables "Gross National Income" and "ecological footprint," and test the second individual-level hypothesis with logistic regressions of the variables "income" and "donation to environmental groups," from both the General Social Survey and the World Values Survey. The results strongly refute Huber's national-level theory, with evidence that wealthy nations are actually less efficient at using land, but on an individual level the evidence suggests that the wealthy are indeed more likely to donate money to environmental groups. / Master of Science

Transgenic techniques have rapidly evolved in recent years. However, the efficiency of these techniques to produce viable offspring is still disappointingly low. The purpose of this study was to assess in vitro development, transgene expression, and integration following pronuclear or cytoplasmic microinjection of condensed or linear green fluorescent protein DNA into murine embryos using electroporation. In experiment 1, the effect of embryo orientation (group or linear) within the electroporation chamber on development was evaluated using zygotes which received one pulse duration (10 msec), and one of two voltages (250 or 400 V). Zygotes that received 400 V had the lowest development score (Group, 2.06 ? 0.12; Linear, 1.97 ? 0.13), irrespective of orientation. Embryos that received 250 V had the highest development of the voltage treated groups (Group 3.42 ? 0.12; Linear 3.32 ? 0.12), irrespective of orientation, and development was lower than the control embryos (Control 4.28 ? 0.12; Mannitol control 4.36 ? 0.18). In experiment 2, the efficiency of utilization of the prepared enhanced green fluorescent protein (EGFP) construct as a visual marker of protein expression was evaluated using pronuclear microinjection. Embryo development and fluorescence were evaluated following pronuclear injection of EGFP at a concentration of 3 μg/ml and compared to an uninjected control. Embryos injected with the EGFP had lower development scores (3.85 ± 0.15) than uninjected control embryos (5.72 ± 0.2). Of the embryos injected, 32.4% fluoresced due to expression of EGFP. Experiment 3 evaluated the effect of combining cytoplasmic injection of EGFP (425 μg/ml) with electroporation at 250 V on EGFP expression. The non-manipulated control embryos had significantly higher (P < 0.01) 4 d development scores (5.57 ± 0.11) than manipulated control embryos (4.6 ± 0.18), where the injection needle was inserted into the cytoplasm and no DNA was injected. Combining cytoplasmic DNA injection and electroporation caused a significant (P < 0.01) decrease in development scores, irrespective of DNA construct, when compared to embryos injected with a DNA construct alone. The mechanical effects of needle insertion combined with electroporation were not significantly different (P > 0.05) from embryos injected with DNA alone, irrespective of construct injected. Cytoplasmic injection of condensed DNA (0.38%), linear DNA (0.38%), and condensed DNA combined with electroporation (0.36%) resulted in one fluorescent embryo respectively. Cytoplasmic injection of linear DNA when combined with electroporation (3.57%) resulted in 13 fluorescent embryos. Pronuclear injection of the prepared EGFP construct results in lower development than control embryos. Electrical stimulation of zygotes reduces early embryo development. However, low amounts of electrical stimulation may allow for enhancement of gene integration in transgenic embryos. / Master of Science

No / Tranquility has a number of facets. Given the role that tranquility plays in societies, it is increasingly seen as an environmental indicator. Earlier, some have identified tranquility as contributing to health and wellbeing of individuals and the society, making it to be rooted in the context of sound natural ecosystems as a desirable environmental characteristic. Previous studies have identified tranquility places as having links to nature and natural features, wild landscapes, naturally behaving wildlife and natural sounds. The question of how tranquility can be evaluated and the perception of tranquility by visitors is a continuous recurrence. This study therefore selected seven green open spaces in Hong Kong in an attempt to answer these and other questions that are arising. Although results vary, it however provides a perspective on how people perceive tranquil spaces as part of their leisure and recreation indulgence, given rise to the concept of eco-leisure. / Research Grants Council of the Hong Kong Special Administrative Region, China (RGC/GRF, CUHK449612)

No description available.

No description available.

No description available.

<P> There is a growing interest in magnesium and its alloys due to their high strength to weight ratio. Magnesium is of particular interest to the automotive industry as a consequence of the current pressure to reduce green house gas emissions from the transportation sector through vehicle weight reduction. However, there is a lack of knowledge concerning the formability of magnesium. As a result, the application of magnesium as a commercial material has not been fully exploited. Much has been learned from the constitutive modeling of materials such as aluminum and steel. Therefore, this thesis considers the constitutive modeling of magnesium and its alloys. </p> <p> Based on this motivation, polycrystal plasticity theories that have been established and used to characterize aluminum and steel are studied. The validity of these theories is examined with respect to magnesium and its alloys. The magnesium system is composed of the hexagonal closed-packed (HCP) crystal structure. Therefore, a strong plastic anisotropy is induced in magnesium crystals due to the limited number of slip systems that may be activated with ease. The models proposed by Taylor and Sachs neglect strain and stress heterogeneities respectively. As a result, the models are either too stiff or too soft to study magnesium due to the anisotropic nature of the crystal structure. The intermediate models; self-consistent models, which are able to consider the heterogeneities among the grains in polycrystals, are believed to be more suitable to study magnesium and its alloys. Therefore, a large strain elastic-viscoplastic self-consistent (EVPSC) model is developed for polycrystalline materials. Both rate sensitive slip and twinning are included as mechanisms of plastic deformation, while elastic anisotropy is accounted for in the elastic modulus. The transition from single crystal plasticity to polycrystal plasticity is based on a completely self-consistent approach. It is shown that the differences in the predicted stress-strain curves and texture evolutions based on the EVPSC and the viscoplastic self-consistent (VPSC) model proposed by Lebensohn and Tome (1993) are negligible at large strains for monotonic loadings. For the deformations involving unloading and strain path changes, the EVPSC predicts a smooth elasto-plastic transition, while the VPSC model gives a discontinuous response because the model is incapable of modeling elastic deformation. In addition, it is demonstrated that the EVPSC model can capture some important experimental features which cannot be simulated by using the VPSC model. </p> <p> Various self-consistent schemes exist for EVPSC and VPSC models. However, the evaluations of these models are not complete. Therefore, an examination of various polycrystal plasticity models is made, based on comparisons of the predicted and experimental stress responses as well as the R values, to assess their validity. It is established that, among the models examined, the self-consistent models with grain interaction stiffuess values halfway between those of the limiting Secant (stiff) and Tangent (compliant) approximations give the best results. Among the available options, the Affine self-consistent scheme results in the best overall performance. Furthermore, it is demonstrated that the R values under uniaxial tension and compression within the sheet plane show a strong dependence on the imposed strain. This suggests that the development of anisotropic yield functions using measured R values, must account for the strain. dependence. </p> <p> The recently developed large strain elastic visco-plastic self-consistent (EVPSC) model, which incorporates both slip and twinning deformation mechanisms, is used to study .the lattice strain evolution in extruded magnesium alloy AZ31 under uniaxial tension and compression. The results are compared against in-situ neutron diffraction measurements done on the same alloy. For the first time, the effects of stress relaxation and strain creep on lattice strain measurements in respectively displacement controlled and load controlled in-situ tests are numerically assessed. It is found that the stress relaxation, has a significant effect on the lattice strain measurements. It is also observed that although the creep does not significantly affect the trend of the lattice strain evolution, a better agreement with the experiments is found if creep is included in the simulations. </p> <p> In conjunction with the M-K approach developed by Marciniak and Kuczynski (1967), the EVPSC model is applied to study the sheet metal formability of magnesium alloys in terms of the forming limit diagram (FLO). The role of crystal plasticity models and the effects of basal texture on formability of magnesium alloy AZ31 B sheet are studied numerically. It is observed that formability in HCP polycrystalline materials is very sensitive to the intensity of the basal texture. The path-dependency of formability is examined based on different non-proportional loading histories, which are combinations of two linear strain paths. It is found that while the FLO in strain space is very sensitive to strain path changes, the forming limit stress diagram (FLSO) in stress space is much less path-dependent. It is suggested that the FLSO is much more favourable than the FLO in representing forming limits in the numerical simulation of sheet metal forming processes. The numerical results are found to be in good qualitative agreement with experimental observations. </p> / Thesis / Doctor of Philosophy (PhD)

Green tea contains high concentrations of polyphenolic compounds known as catechins. Studies in animal models suggest several potential mechanisms for specific metabolic effects at rest and during exercise, including improved glycemic control, altered activity of several glucose transporter proteins and improved endurance capacity. In humans, green tea extract (GTE) supplementation has been associated with improved glycemic control under resting conditions and increased fat oxidation during exercise. This dissertation examined the potential interactive effects of GTE supplementation and exercise on metabolism in humans with a focus on glycemic control. In Study 1, we demonstrated that GTE increased lipolysis and reduced heart rate during steady-state exercise in recreationally active men. Although substrate oxidation was not affected, GTE appeared to lower postprandial glucose under resting conditions. We hypothesized that the effects of GTE on exercise metabolism and glycemic control would be more apparent in humans with reduced exercise tolerance and impaired glucose tolerance. Thus, in Study 2, we examined the effects of GTE in sedentary overweight men. There were no differences in any metabolic or physiological responses during exercise; however, following exercise, GTE supplementation reduced [glucose] and insulinemia in response to an oral glucose load. Based on the findings of Study 2, the aim of Study 3 was to elucidate potential mechanisms for the alterations in glycemic response. Through the use of a dual-glucose tracer method, we demonstrated that GTE did not affect the rate of appearance of glucose in plasma in sedentary men; however, GTE supplementation allowed for the same glucose clearance rate despite a reduced insulinemia. We also observed lower carbohydrate oxidation during exercise with GTE. These findings suggest that GTE has an insulin-sensitizing effect during recovery from exercise, possibly due to enhanced glucose transporter activity; however, this hypothesis warrants further investigation in humans. / Dissertation / Doctor of Science (PhD) / Tea is one of the most popular beverages in the world. Compared to other teas, green tea has a greater abundance of catechins, compounds that have been associated with health benefits particularly related to the metabolism of sugars and fats. This unique property of green tea could partly explain its longstanding medicinal role in some Asian cultures. Extensive research on green tea has increased its popularity over the past three decades. Studies involving both humans and other animals have shown improvements in weight control and glycemic control. In response to these findings green tea is often touted as having “anti-obesity” and anti-diabetic” properties. This dissertation examined the interaction between green tea extract supplementation and exercise on metabolism with a particular focus on blood sugar control. We observed that supplementation with green tea extract improved the response to sugar ingested after exercise. This finding has important implications for improving the control of ingested sugar in humans.

This thesis is an exploration of numerical modeling and design of intra-cavity frequency doubled green lasers, which is one of the three key light sources in laser display systems. In this thesis the time-domain traveling wave (TDTW) model, which is well developed to model integrated photonic devices, is derived for modeling and design of a new proposed device. The device is based on the intra-cavity frequency doubling of high power distributed Bragg reflector laser diodes (DBRLD) and MgO-doped periodically poled lithium niobate (MgO:PPLN) waveguides. The numerical modeling and design suggest the superiority of the proposed intra-cavity frequency doubled DBR-LD/MgO:PPLN green laser over traditional single-pass frequency doubled DBRLD-LD/MgO:PPLN green laser. A plane-wave based coupled-wave model is implemented to model miniature intra-cavity frequency doubled DPSS lasers. Good agreement between the planewave model and experiment has been obtained. By employing the plane-wave model, we have explained the phase problem in our optical contact Nd:YVO4/MgO:PPLN green laser. Design examples of wide temperature operation of Nd:YVO4/MgO:PPLN green lasers are also completed by this numerical method. Finally, to model high power bulk intra-cavity frequency doubled diodepumped solid-state (DPSS) green lasers, a three-dimensional coupled-wave model is developed and compared with experimental results. A two-dimensional thermal model is incorporated into the three-dimensional coupled-wave equations to model thermal lensing and thermal de-phasing effects in intra-cavity frequency doubled DPSS lasers. The numerical models we developed are validated by the experimental results. / Thesis / Doctor of Philosophy (PhD)