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It all started with one of my deep memories -- when I was a child, and first saw QINGMING FESTIVAL, a masterpiece created by great painter, Zhang Zeduan, I was attracted by the riverside city scene of Song dynasty, and was surprised by the amiable atmosphere among citizens social life and the comfortable sense of urban scale. This memory has deeply affected me. In contrast, our Chinese newborn modern cities become dreadfully alike, with their monotonous expansion, and meanwhile, they gradually lost their intimate sense of scale and regional sense of identity that they once had. Bridge, as one of Chinese infrastructural development, not only indicates the Chinese urban development in history, but its role and responsibilities go beyond its proper functions. No matter who we are, ancient Chinese or modern Chinese, their love for the bridge have beyond the practicability of the bridge itself. The bridge has a deep cultural heritage in a sense. Since such issues have arisen in our contemporary cities, why not date back to the origins of Chinese cities development -- to reinterpret the function of bridges so that reshape the scale of entire city by using modern architectural language? / Master of Architecture

Mixing of miscible gas with oil in a reservoir decreases the effective strength of the gas, which can adversely affect miscibility and recovery efficiency. The mixing that occurs in a reservoir, however, is widely debated and often ignored in reservoir simulation, where very large grid blocks are used. Large grid blocks create artificially large mixing that can cause errors in predicted oil recovery. Reservoir mixing, or dispersion, is caused by diffusion of particles across streamlines of varying velocities. Mixing is enhanced by any mechanism that increases the area of contact between the gas and the oil, thereby allowing the effects of diffusion to be magnified. This is, in essence, the cause of scale-dependent dispersion. The contact area grows primarily because of variations in streamlines and their velocities around grains and through layers of various permeabilities (heterogeneity). Mixing can also be enhanced by crossflow, such as that caused by gravity and by the effects of other neighboring wells. This dissertation focuses on estimation of the level of effective local mixing at the field scale and its impact on oil recovery from miscible gas floods. Pore-level simulation was performed using the Navier-Stokes and convection-diffusion equations to examine the origin of scale dependent dispersion. We then estimated dispersivity at the macro scale as a function of key scaling groups in heterogeneous reservoirs. Lastly, we upscaled grid blocks to match the level of mixing at the pattern scale. Once the contact area ceases to grow with distance traveled, dispersion has reached its asymptotic limit. This generally occurs when the fluids are well mixed in transverse direction. We investigated a variety of pore-scale models to understand the nature of scale dependency. From the pore-scale study, we found that reservoir mixing or dispersion is caused by diffusion of particles across streamlines. Diffusion can be significantly enhanced if the surface area of contact between the reservoir and injected fluid are increased as fluids propagate through the reservoir. Echo and transmission dispersivities are scale dependent. They may or may not reach an asymptotic limit depending on the scale of heterogeneities encountered. The scale dependence results from an increase in the contact area between solute (gas) and resident fluid (oil) as heterogeneities are encountered, either at the pore or pattern-scale. The key scaling groups for first-contact miscible (FCM) flow are derived and their impact on mixing is analyzed. We examine only local mixing, not apparent mixing caused by variations in streamline path lengths (convective spreading). Local mixing is important because it affects the strength of the injected fluid, and can cause an otherwise multicontact miscible (MCM) flood to become immiscible. We then showed how to upscale miscible floods considering reservoir mixing. The sum of numerical dispersion and physical dispersion associated with the reservoir heterogeneities, geometry and fluid properties must be equal at both the fine- and large-scales. The maximum grid-block size allowed in both the x- and z-directions is determined from the scaling groups. Small grid-blocks must be used for reservoirs with uncorrelated permeabilities, while larger grid blocks can be used for more layered reservoirs. The predicted level of mixing for first-contact miscible floods can be extended with good accuracy to multicontact miscible (MCM) gas floods. / text

Climate is one of the most important factors influencing where wine grapes can be grown and the quality of wine produced from those grapes. A plants habitat has a profound influence on its growth and development. The surrounding climatic conditions at both the macro- and meso-scales influence the plant-climate miro-scale interactions. The main study site is the McKenzie Vineyard that is owned by Torlesse Wines. The climatic conditions of the surrounding Waipara region was also studied using climate data from the following vineyards; Canterbury House, River Terrace and Waipara West. The overall aim of this research is to improve understanding of the influence of the climatic environment on grapevine development at the meso- to micro-scale. The main findings of the research were firstly, that the most important climatic factor influencing grapevine development and growth is temperature and secondly that there is variability in the temperature across the Waipara Basin. Future research should be conducted for the entire growth season to gain a better understanding of how temperature influences the development of grapevine over the growing season as a whole.

Thesis advisor: Michael Russell / For more than a half century surveys and questionnaires with Likert-scaled items have been used extensively by researchers in schools to draw inferences about students; however, to date there has not been a single study that has examined whether alternative item response types on a survey might lead to different results than those obtained with Likert scales in a K-12 setting. This lack of direct comparisons leaves the best method of framing response options in educational survey research unclear. In this study, 4th through 12th grade public school students were administered two versions of the same survey online: one with Likert-scaled response options and the other with visual analogue-scaled response options. A randomized, fixed-effect, between-subjects experimental design was implemented to investigate whether the survey with visual analogue-scaled items yielded results comparable to the survey with Likert-scaled items based on the following four methods and indices: 1) factor structure; 2) internal consistency and test-retest reliability; 3) survey summated scores; and 4) main, interaction, and simple effects. Results of the first three indices suggested that both the Likert scale and visual analogue scale produced similar factor structures, were equally reliable, and yielded summated scores that were not significantly different across all three school levels (elementary, middle, and high school). Results of the factorial ANOVA suggested that only the main effect of school level was statistically significant but that there was no significant interaction between item response type and school level. Results of the post-survey questionnaires suggested that students at all school levels preferred answering questions on the survey with the VAS compared to the LS nearly three to one. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement, and Evaluation.

Scale formation is one of the persistent problems in mineral processing and related industries. One of the main components of the scale is frequently gypsum or calcium sulphate dihydrate (= CaS04.2H20). Gypsum is formed through the process of crystallisation, and it is well known that crystallisation process is significantly affected by the presence of admixtures. Industrially, scale formation occurs in an environment which is very rarely free from the presence of admixtures. In a typical mineral processing industry, certain types of admixtures are present, which may include metallic ions (e.g. originated from corrosion products) and certain types of the flotation agents used. The effect of admixtures on crystallisation kinetics and cyclical morphology can be very significant, even if they are present in trace amounts. It is important to emphasise that the effects are generally specific, that there is no unified theory that applies to all and every situation. The present study has investigated the effect of certain admixtures on gypsum crystallisation, and was accomplished in three phases of experiments: (1) seeded batch crystallisation; (2) seeded continuous crystallisation, and (3) once through flow system under isothermal condition. The three phases of the work used equimolar solutions of CaC12 and Na2SO4 to produce CaS04 which is the precipitating species. The seeded batch crystallisation experiment explored the effect of two flotation agents commonly used in mineral processing plants: (1) sodium isopropyl xanthate (= SIPX) and, (2) isopropyl thionocarbamate. The experiments were performed at 25, 35, and 45°C, respectively. The initial concentration of the crystallising solution was 2,000 ppm of Ca 21 and it reached the equilibrium concentration values of between 1,000 and 8,00 ppm of Ca 2+ in 90 minutes. / The effect of the two selected admixtures on crystallisation was measured by continuous monitoring of the desupersaturation of the crystallising solution with time, which subsequently resulted in the determination of the crystallisation rate constant. The results arc as follows. Firstly, the admixtures selected (either individually or in combination) were able to retard the growth rate of gypsum. In the absence of any admixture, the second order rate constant was between 1,405 x 10-6 and 1,561 x 10-6 ppm-1 min-1. Addition of SIPX at a typical plant dosing level 0.200 g/L) reduced the rate constant to 475 x 10-6 PPM-1 min', while isopropyl thionocarbamate at a typical plant dosing level (= 0.070 g/L) decreased the rate constant to 254 x 10-6 ppm-1 min-'. However, addition of a combination of the two admixtures, each at a typical plant concentration level, reduced the rate constant to 244 x 10-6 ppm-1 min-1, which was only slightly below that in the presence of isopropyl thionocarbamate. Thus, in these batch crystallisation studies, isopropyl thionocarbamate seemed to be dominant over SIPX. Secondly, the batch crystallisation system in the current work did not show any induction time. It was concluded that the seeds added into the batch system could be capable of eliminating the induction time. Thirdly, the reduced growth rate of the gypsum crystals as affected by the admixtures was probably caused by the adsorption of admixtures onto the crystal surface. The second phase of the project involved a seeded continuous (MSMPR) crystalliser. Some parameters used in this experiment (mean residence time, agitation speed and type of one admixture) were taken from the batch experiment carried out in the first phase of the project. / Three admixtures were chosen for the seeded continuous crystallisation: (1) SIPX, (2) Fe3+, (3) Zn2-, and they were used either individually on in combination with each other. SIPX was chosen as it is one of the most common flotation agents used in mineral processing. Metallic ions: Fe3+ and Zn2+ were selected, since they were found in substantial amounts in both scale samples and process water in certain minerals processing industries. In general, the admixtures tested were found to be able to inhibit the crystal growth rates, but to enhance the nucleation rates. In addition, the growth rate was found to be dependent on crystal size, and hence, a correlation between these two parameters and the admixture concentration was formulated. For a fixed level of concentration (f 700 ppm of Ca z+ at steady state) and crystal surface area, it was proved that for each crystallisation temperature: 25 and 40°C, the correlation function can be represented as G = k Lα (1 +C)β where: G = linear growth rate, micron/hour; k, α, and β = dimensionless constants; L = (sphere equivalent) crystal size, micron; C = concentration of the admixtures used, ppm. For both the crystallisation temperatures used, the correlation function shows that the growth rate is significantly dependent on crystal size, but a weak function of admixture concentrations. The mechanism of crystal growth inhibition was assumed to be that of adsorption of admixtures onto the active growth sites, thereby decreasing or stopping the growth. Similar to the first phase of the present study, this seeded continuous crystallisation also showed no induction time. The third phase of the project investigated the gypsum scale formation in a oncethrough pipe flow system under isothermal condition and in the presence of admixtures. / Four types of pipe materials were tested: PVC, brass, copper and stainless steel. Two admixtures were selected: SIPX and Fe3+. The behaviour of the gypsum scale formation was measured as the mass of the gypsum scale deposited on the substrate per unit area of the pipe surface. Within the range of the experimental conditions applied in this scale formation study, the following results were obtained. Firstly, the mass of the gypsum scale increased with concentration (in the range: 2,000 to 6,000 ppm of Ca t+) and that the correlation between the mass and the concentration can be represented by quadratic functions. Secondly, the mass of the gypsum scale decreased with increasing concentration of the admixtures used. Thirdly, the flow rate of the scaling solutions (in the range: 0.4 to 1.3 cm/sec) did not significantly affect the mass of the gypsum scale. PVC produced the highest mass of gypsum scale, followed by brass, copper, and stainless steel, respectively. Fourthly, the presence of admixtures caused the surface of the scale deposit to become rougher than was the case in a pure system, and longer scaling experimental times resulted in denser scale deposits. In this scale formation project, the induction time was investigated. In contrast with the first and the second phase of the projects, the induction time in the scale gypsum formation experiment was significant. At a concentration of 2,000 ppm of Ca 2+' pure gypsum solutions had induction times of about 105 minutes at 18.3°C and 97 minutes at 20.3°C. In the presence of 10 ppm of SIPX, the scaling solution at 2,000 ppm of Ca2+ and 19.2°C had an induction time of 1,400 minutes. The present study produced three important findings. / Firstly, the presence of Fe 3+ or sodium isopropyl xanthate (SIPX) reduced the growth rate of gypsum crystallised either in a vessel (= a continuous crystalliser) or in a pipe flow system. Secondly, the rate of growth of gypsum crystals was found to be consistently higher in the vessel than in the pipe flow system. The rate of growth of the pure gypsum in the crystalliser at 25°C was 0.0389 kg/ m2 hour while those in the pipe flow system were between 0.0289 and 0.0202 kg/m2 hour, depending on the pipe material and the scaling solution flow rate. Thirdly, with respect to gypsum scaling, PVC was the least favourable material, followed by brass and copper, while the most favourable was stainless steel. It is believed that the present study has significantly contributed to the understanding of the effect of admixtures on crystallisation of gypsum, especially in relation to the scale formation.

While most ecotourist definitions and typologies have relied on concepts ingrained in traveler behaviours or destinations, none has benefited from a consideration of personal ethics. The study of ecotourism has virtually ignored theoretical considerations of ethics, other than making comparisons with the broader tourism sector. An additional shortcoming is the general lack of methodological sophistication, where the bulk of research concerning ecotourism has remained exploratory and descriptive, and has not sought to understand and explain the role that ethics have played, or not, in ecotourist behaviour and developmental practices. The assumption that ecotourists possess a higher level of ethical beliefs than mass tourists, and in fact exhibit ethical behaviour, has not been contested to a sufficient degree. Consequently, this dissertation addresses a need for more conceptually-based research to identify core ethics underlying ecotourist behaviour, with the potential to reveal where quite diverse groups, including those with different cultural orientations, are positioned on these Western philosophical stances. Upon building a conceptual understanding of ecotourist ethics, I have developed a conceptually-driven, multi-dimensional scale – the Ecotourist Ethics Scale (EES) – based on a conceptual framework that draws on classic theories of ethics (Deontology, Teleology, and Existentialism) and on dominant components of ecotourism definitions, frameworks, and typologies (Nature, Culture, Education, and Conservation). This first phase of scale development was followed by a second phase of testing the EES for its validity and reliability with a sample of 1,544 students, and additionally, testing its concurrent validity in relation to four other established scale measures conceptually related to ecotourist ethics. The results of employing the EES indicate ethics based on Deontology and Teleology define the prevalent ethical stances held by individuals where the focus appears to be on rules or principles and consequences, and not on the authenticity of the experience or activity. The development of a profile of travelers based on ethics, as opposed to typologies based simply on settings, behaviours, or occasionally psychographics, could not only advance our understanding of these travelers, but also provide a means for ecotour companies to implement management strategies for a more sustainable operation in response to the array of positive and negative beliefs and behaviours driven by core ethics. The dissertation concludes with a discussion of findings and their implications from analyses of an assortment of the factors related to the sample’s travel and demographic characteristics.

Multi-scale modeling of chemical vapor deposition (CVD) is a very broad topic because a large number of physical processes affect the quality and speed of film deposition. These processes have different length scales associated with them creating the need for a multi-scale model. The three main scales of importance to the modeling of CVD are the reactor scale, the feature scale, and the atomic scale. The reactor scale ranges from meters to millimeters and is called the reactor scale because it corresponds with the scale of the reactor geometry. The micrometer scale is labeled as the feature scale in this study because this is the scale related to the feature geometries. However, this is also the scale at which grain boundaries and surface quality can be discussed. The final scale of importance to the CVD process is the atomic scale. The focus of this study is on the reactor and feature scales with special focus on the coupling between these two scales. Currently there are two main methods of coupling between the reactor and feature scales. The first method is mainly applied when a modified line of sight feature scale model is used, with coupling occurring through a mass balance performed at the wafer surface. The second method is only applicable to Monte Carlo based feature scale models. Coupling in this second method is accomplished through a mass balance performed at a plane offset from the surface. During this study a means of using an offset plane to couple a continuum based reactor/meso scale model to a modified line of sight feature scale model was developed. This new model is then applied to several test cases and compared with the surface coupling method. In order to facilitate coupling at an offset plane a new feature scale model called the Ballistic Transport with Local Sticking Factors (BTLSF) was developed. The BTLSF model uses a source plane instead of a hemispherical source to calculate the initial deposition flux arriving from the source volume. The advantage of using a source plane is that it can be made to be the same plane as the coupling plane. The presence of only one interface between the feature and reactor/meso scales simplifies coupling. Modifications were also made to the surface coupling method to allow it to model non-uniform patterned features. Comparison of the two coupling methods showed that they produced similar results with a maximum of 4.6% percent difference in their effective growth rate maps. However, the shapes of individual effective reactivity functions produced by the offset coupling method are more realistic, without the step functions present in the effective reactivity functions of the surface coupling method. Also the cell size of the continuum based component of the multi-scale model was shown to be limited when the surface coupling method was used. Thanks to the work done in this study researchers using a modified line of sight feature scale model now have a choice of using either a surface or an offset coupling method to link their reactor/meso and feature scales. Furthermore, the comparative study of these two methods in this thesis highlights the differences between the two methods allowing their selection to be an informed decision.

While most ecotourist definitions and typologies have relied on concepts ingrained in traveler behaviours or destinations, none has benefited from a consideration of personal ethics. The study of ecotourism has virtually ignored theoretical considerations of ethics, other than making comparisons with the broader tourism sector. An additional shortcoming is the general lack of methodological sophistication, where the bulk of research concerning ecotourism has remained exploratory and descriptive, and has not sought to understand and explain the role that ethics have played, or not, in ecotourist behaviour and developmental practices. The assumption that ecotourists possess a higher level of ethical beliefs than mass tourists, and in fact exhibit ethical behaviour, has not been contested to a sufficient degree. Consequently, this dissertation addresses a need for more conceptually-based research to identify core ethics underlying ecotourist behaviour, with the potential to reveal where quite diverse groups, including those with different cultural orientations, are positioned on these Western philosophical stances. Upon building a conceptual understanding of ecotourist ethics, I have developed a conceptually-driven, multi-dimensional scale – the Ecotourist Ethics Scale (EES) – based on a conceptual framework that draws on classic theories of ethics (Deontology, Teleology, and Existentialism) and on dominant components of ecotourism definitions, frameworks, and typologies (Nature, Culture, Education, and Conservation). This first phase of scale development was followed by a second phase of testing the EES for its validity and reliability with a sample of 1,544 students, and additionally, testing its concurrent validity in relation to four other established scale measures conceptually related to ecotourist ethics. The results of employing the EES indicate ethics based on Deontology and Teleology define the prevalent ethical stances held by individuals where the focus appears to be on rules or principles and consequences, and not on the authenticity of the experience or activity. The development of a profile of travelers based on ethics, as opposed to typologies based simply on settings, behaviours, or occasionally psychographics, could not only advance our understanding of these travelers, but also provide a means for ecotour companies to implement management strategies for a more sustainable operation in response to the array of positive and negative beliefs and behaviours driven by core ethics. The dissertation concludes with a discussion of findings and their implications from analyses of an assortment of the factors related to the sample’s travel and demographic characteristics.