The successful production of a wide range of polymer latex products relies on the ability to control the rates of particle nucleation, growth and coagulation in order to maintain control over the particle size distribution (PSD). The development of advanced population balance models (PBMs) has simplified this task at the laboratory scale, but commercialization remains challenging as it is difficult to maintain control over the composition (i.e. spatial distributions of reactant concentration) of larger reactors. The objective of this thesis is to develop and test a combined Computational Fluid Dynamics (CFD) -PBM hybrid modeling framework. This hybrid modeling framework can be used to study the impact of changes in process scale on product quality, as measured by the PSD. The modeling framework developed herein differs from previously-published frameworks in that it uses information computed from species tracking simulations to divide the reactor into a series of interconnected zones, thereby ensuring the reactor is zoned based on a mixing metric. Subsequently, an emulsion polymerization model is solved on this relatively course grid in order to determine the time evolution of the PSD. Examination of shear rate profiles generated using CFD simulation (at varying reactor scales) suggests that, dependent on conditions, mechanically-induced coagulation cannot be neglected at either the laboratory or the commercial scale. However, the coagulation models that are formulated to measure the contributions of both types of coagulation simultaneously are either computationally expensive or inaccurate. For this reason the decision was made to utilize a DLVO-coagulation model in the framework. The second part of the thesis focused on modeling the controlled coagulation of high solids content latexes. POLY3D, a CFD code designed to model the flow of non-Newtonian fluids, was modified to communicate directly with a multi-compartment PBM. The hybrid framework was shown to be well-suited for modeling the controlled coagulation of high solid content latexes in the laminar regime. It was found that changing the size of the reactor affected the latex PSD obtained at the end of the process. In the third part of the thesis, the framework was adapted to work with Fluent, a commercial CFD code, in order to investigate the scale-up of a styrene emulsion polymerization reaction under isothermal conditions. The simulation results indicated that the ability to maintain good control of the PSD was inversely related to the reactor blend time. While the framework must be adapted further in order to model a wider range of polymerization processes, the value of the framework, in obtaining information that would otherwise be unavailable, was demonstrated. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-05-01 07:09:08.362

L'éclatement est une transformation jouant un rôle important en géométrie, car il permet de résoudre des singularités, de relier des variétés birationnellement équivalentes, et de construire des variétés possédant des propriétés inédites. Ce mémoire présente d'abord l'éclatement tel que développé en géométrie algébrique classique. Nous l'étudierons pour le cas des variétés affines et (quasi-)projectives, en un point, et le long d'un idéal et d'une sous-variété. Nous poursuivrons en étudiant l'extension de cette construction à la catégorie différentiable, sur les corps réels et complexes, en un point et le long d'une sous-variété. Nous conclurons cette section en explorant un exemple de résolution de singularité. Ensuite nous passerons à la catégorie symplectique, où nous ferons la même chose que pour le cas différentiable complexe, en portant une attention particulière à la forme symplectique définie sur la variété. Nous terminerons en étudiant un théorème dû à François Lalonde, où l'éclatement joue un rôle clé dans la démonstration. Ce théorème affirme que toute 4-variété fibrée par des 2-sphères sur une surface de Riemann, et différente du produit cartésien de deux 2-sphères, peut être équipée d'une 2-forme qui lui confère une structure symplectique réglée par des courbes holomorphes par rapport à sa structure presque complexe, et telle que l'aire symplectique de la base est inférieure à la capacité de la variété. La preuve repose sur l'utilisation de l'éclatement symplectique. En effet, en éclatant symplectiquement une boule contenue dans la 4-variété, il est possible d'obtenir une fibration contenant deux sphères d'auto-intersection -1 distinctes: la pré-image du point où est fait l'éclatement complexe usuel, et la transformation propre de la fibre. Ces dernières sont dites exceptionnelles, et donc il est possible de procéder à l'inverse de l'éclatement - la contraction - sur chacune d'elles. En l'accomplissant sur la deuxième, nous obtenons une variété minimale, et en combinant les informations sur les aires symplectiques de ses classes d'homologies et de celles de la variété originale nous obtenons le résultat. / The blow-up is a transformation which plays an important role in geometry, because it can be used to resolve singularities, relate birationally equivalent varieties, and construct varieties with new properties. This thesis first presents blowing-up as developped in classical algebraic geometry. We will study it in the case of affine and (quasi-)projective varieties, on a point and along an ideal and a subvariety. Then a discussion about its extension to the differential category will be carried out, over the real and complex fields, on a point and along a submanifold. An example of a resolution of singularity will then follow. Subsequently we will discuss blowing-up in the symplectic category, where we will do the same as for complex manifolds, paying careful attention to the symplectic form. To conclude, we will study a theorem by François Lalonde, where the symplectic blow-up plays a major part in proof. This theorem states that any 4-variety fibered by 2-spheres over a Riemann surface, and different than the Cartesian product of two 2-spheres, can be equiped with a 2-form giving it a symplectic structure ruled by curves that are holomorphic with respect to its almost-complex structure, and such that the symplectic area of the base is smaller that the capacity of the variety. In the proof, we blow up a ball in the 4-variety, and obtain a fibration containing two distinct spheres with a self-intersection equal to -1: the pre-image of the point where the usual complex blow-up is done, and the proper transform of the fiber. These two are exceptional, so it is possible to do the inverse operation - the blow down - on each of them. By blowing down the latter, we get a minimal variety, and by combining information about the symplectic area of its homology classes and of those of the original variety, we obtain the result.

In a climate change perspective, increased air temperatures are already a reality and are expected to increase even more in the future, especially in areas at high latitudes. The present thesis therefore addresses the influence of climate change on the physical properties and the phytoplankton communities of typical small and oligotrophic lakes in northern Sweden (62-64˚N). In the first part of the study, we found a significant trend (10 lakes from 1916 to 2010) of ice break-ups occurring increasingly earlier. The timing of ice break-up was strongly influenced by the April air temperature indicating that expected increases in air temperature in the future will also result in an earlier ice break-up. We also used concentrations of chlorophyll a (chl a) as estimations of phytoplankton biomass and discovered a positive relationship between surface water temperature and concentrations of chl a in Lake Remmaren (from 1991 to 2008). The second part of the thesis focuses on climatic conditions and cyanobacteria abundance in three small, oligotrophic lakes in northern Sweden; Lake Remmaren, Lake S. Bergsjön and Lake Gransjön. The concentration and relative abundance of cyanobacteria differ between 2011 and 2012, with different climatic conditions. The "warm" year of 2011 had higher concentrations and relative abundance of cyanobacteria than the "cold" year of 2012. Trends in increasing surface water temperatures as well as increasing abundance of cyanobacteria in August were found in Lake Remmaren (from 1988 to 2011). The direct or indirect effects of warming had a positive effect on the cyanobacteria abundance, since nutrients (Tot N and Tot P) did not display an increasing trend in Lake Remmaren. An analysis on the composition of phytoplankton species in Lake Remmaren, Lake S. Bergsjön and Lake Gransjön revealed that the cyanobacteria Merismopedia sp. was more common in 2011 than 2012. If different cyanobacteria become more common in oligotrophic lakes in the future, the functioning of lake ecosystems may be impacted. Small zooplankton eats small phytoplankton and if smaller phytoplankton species, e.g. cyanobacteria, increase at the expense of other phytoplankton groups, an extra step in the food chain might be added. Less energy might be transferred to the upper levels because many cyanobacteria contain toxic compounds and are less edible than other phytoplankton groups. An increase of toxic containing cyanobacteria in lakes can also make lakes less attractive for recreational purposes in the future.

Start-up firms play an important role in the economy. Statistics show that a large percent of start-up firms fail after few years of establishment. Raising capital, which is crucial to success, is one of the difficulties start-up firms face. This Ph. D thesis aims to draw suggestions for start-up firm survival from mathematical models and numerical investigations. Instead of the commonly held profi t maximizing objective, this thesis assumes that a start-up firm aims to maximize its survival probability during the planning horizon. A firm fails if it runs out of capital at a solvency check. Inventory management in manufacturing start-up firms is discussed further with mathematical theories and numerical illustrations, to gain insight of the policies for start-up firms. These models consider specific inventory problems with total lost sales, partial backorders and joint inventory-advertising decisions. The models consider general cost functions and stochastic demand, with both lead time zero and one cases. The research in this thesis provides quantitative analysis on start-up firm survival, which is new to the literature. From the results, a threshold exists on the initial capital requirement to start-up firms, above which the increase of capital has little effect on survival probability. Start-up firms are often risk-averse and cautious about spending. Entering the right niche market increases their chance of survival, where the demand is more predictable, and start-ups can obtain higher backorder rates and product price. Sensitivity tests show that selling price, purchasing price and overhead cost have the most impact on survival probability. Lead time has a negative effect on start-up firms, which can be offset by increasing the order frequent. Advertising, as an investment in goodwill, can increase start-up firms' survival. The advertising strategies vary according to both goodwill and inventory levels, and the policy is more flexible in start-up firms. Externally, a slightly less frequency solvency check gives start-up firms more room for fund raising and/or operation adjustment, and can increase the survival probability. The problems are modelled using Markov decision processes, and numerical illustrations are implemented in Java.

The objective of this thesis is to determine whether it is possible to improve the adequacy of support to “post start-up” small businesses in Sri Lanka by making changes to the current support regime to encourage their growth. The interest in this issue stems from (a) previous research carried out which highlights the substantially lower contribution to employment growth from the small businesses in Sri Lanka as compared to what is observed in other countries, and (b) the increasing emphasis upon stimulating the small business sector to make a significant contribution to the national economy which is apparent in recent policy proposals in the White Paper presented by the Task Force for Small and Medium Enterprise (SME) development. An examination of extant literature suggests that the understanding of the factors that influence the growth of post start-up small businesses in developing countries is limited. Knowledge is also limited on the type of support that is required to adequately address such factors. To systematically investigate the existing knowledge gaps in these areas a questionnaire survey was conducted. In-depth interviews were also carried out with small business owner-managers and key employees of organisations providing small business support. A variety of statistical techniques were employed to analyse the responses to the questionnaire survey. Overall the results indicate that the factors influencing the growth of post start-up small businesses are highly individual in nature. Results of the study also indicate that the employment growth in post start-up small businesses is very limited. Drawing on the results of the research a conceptual model is proposed that suggests a holistic approach to the identification, evaluation and delivery of support to address the factors constraining the growth of post start-up small businesses.

Many geological numerical models are initiated with a background stress state of zero. Often these numerical results are compared directly to geodetic data. Recent work (Kenner and Simons, 2004) has shown that modeled deformation rates can change as the model is cycled-up following repeated earthquakes or rifting events. In this study, we investigate model cycle-up in the context of time-dependent deformation following rifting during the 1975-1984 Krafla eruption in Iceland. We consider the number of rifting cycles required for complete cycle-up, variations in cycle-up time at different locations in the model, background stress magnitudes in fully cycled-up models, and errors incurred when the models are not properly cycled-up. The modeling is done using the commercial software ABAQUS. In ABAQUS a user-defined subroutine is used to apply repeated rifting events within the finite element model. We have generated various 3D models with different fault/rift geometries. The models include (1) a straight rift oriented perpendicular to the far-field velocity boundary conditions, (2) a rift oriented at an angle to the far-field velocities, (3) a model containing two intersecting rifts, one perpendicular to the far-field velocities and the other rift intersecting the first at an angle, and (4) overlapping rift segments in which the overlapped region is bounded by strike-slip faults.

Since the enactment of the Bayh-Dole Act in 1980, US universities have been given a tacit mandate to manage their intellectual assets in a commercializable way. However, university technology transfer offices have struggled to facilitate innovators and promote economic development because of asymmetric information and processes. After an analysis of premier university technology transfer offices (TTO), an improved methodology, which increases productivity of technology transfer, has been developed. The proposed methodology addresses many of the low level issues facing the commercialization and licensing process. Embedding TTO members with research institutes or colleges, assisting in funding procurement and marketing of research to external firms using innovative media are methods that can minimize technology transfer inefficiency. It is the conclusion of this thesis that improved technology transfer helps promote the overall mission of a university, which is diffusing knowledge for the public benefit.

New Zealand is rapidly becoming a strongly multicultural society with nearly one in four of its citizens born overseas (Statistics New Zealand, 2006). Immigrants enter New Zealand under many different classifications, such as skilled migrants, entrepreneurs, investors, and refugees. Finding employment and a means of survival in their new society is an undeniable challenge for most, if not all, of these immigrants and people from refugee backgrounds. Some of them find employment in established Kiwi organisations while others establish their own businesses and become entrepreneurs. A review of the literature revealed that there has been considerable research on entrepreneurial behaviours of immigrants and refugees in general, but little is known about the experiences of entrepreneurs from refugee backgrounds in New Zealand, specifically Afghan entrepreneurs and how their experiences differ from their counterparts who came to New Zealand from other countries. This qualitative research project studies Afghans (N=23) from Christchurch who established their own businesses and the sense they have made of their experiences, both as refugees and as business owners. It also briefly compares the major findings with those of their refugee counterparts from other countries (N=6) to see if there are any major differences between the two groups’ start-up experiences in New Zealand. Participants were selected from those in the Afghan community in Christchurch who are from a refugee background, using a snowballing technique. The comparison group consisted of six refugees from Zimbabwe, Somalia, South Sudan, Ethiopia and Sri Lanka. The findings of this study have been categorised into two parts. The first part discusses the initial experiences of the participants in New Zealand society, how they settled into New Zealand, what strategies they used to integrate into their new society, how they financed their lives in New Zealand, and eventually how they became economically independent. The second part of the findings discusses the motivators behind the participants’ business start-ups, the types of businesses that they established and how these businesses assisted them as a gateway to other business ventures or activities. This section further investigates the challenges the refugees faced during their business start-up stage and the strategies they adopted to address these challenges. The data indicated that, while the Afghan refugees faced many challenges in establishing their own businesses, three were of particular importance to them. These were (1) financial challenges (2) licensing requirements and (3) English language ability for obtaining business licenses. These were different from the comparison group because of the different industries the two groups of business owners chose to start. This research presents a very important finding. When participants’ experiences were examined to see how they account for personal and business success it was clear it is the social fabric of a collectivist and religious way of life and the associated sense of obligation to support each other that are the most significant factors shaping Afghan refugees’ business start-up behaviour. These factors led them to guide and mentor each other towards economic security and a lifestyle that fitted well with their family and religious obligations and self-identity. In addition to showing how Christchurch Afghan refugees’ business start-ups were used as a means to meet their social objectives, this research and the model that emerged from it offer unique insights into three key drivers: economic security, lifestyle–enterprise fit, and self-identity. These factors, together with age and family circumstances, shaped the decisions associated with starting businesses in New Zealand to determine the pathway chosen. The findings of this research are important as New Zealand is opening its doors to more refugees and very little is known about more recent refugee groups like those from Afghanistan. The findings provide a rich and unique contribution to refugee entrepreneurship and enterprise development literature in New Zealand and a model that could be used as a framework for further studies on the subject by those agencies that support refugees and their business start-up ventures as well as government agencies dealing with refugee resettlement and employment.

Women from across the globe purchase and consume cosmetics in order to achieve their appearance goals and it is generally agreed that a consumers’ goal orientation may influence their interpretation of advertising materials and thus the purchase decision-making process. The cosmetics industry promotes their products using almost exclusively images of attractive, young, highly idealised women, and thus has a significant influence on female appearance ideals worldwide. Extensive research connects viewing idealised images to negative outcomes for consumers’ self-concept, however there are mixed results regarding the effectiveness of idealised models in advertising. Moreover, there are mixed results regarding the effectiveness of different message frames. The overall aim of this thesis is to investigate the effects of possible selves and cosmetic advertising on the consumption of cosmetic products. This research draws together areas of literature which have been studied in varying settings in order to determine the individual and collective effects of these independent variables; possible selves, model idealisation and message framing, on women’s attitude toward cosmetic advertisements and purchase intentions in the cosmetic product context. To understand the effects that goal orientation, as well as the images and text of cosmetic advertisements have on cosmetics consumption, an online experiment was conducted using a 2x3x2 between-subjects factorial design. The study manipulated three independent variables, namely, salient possible self (hoped-for and feared), model idealisation (more idealised model, less idealised model and no model) and regulatory message framing (desired reference and undesired reference) and measured the impact of these variables on attitude toward the ad and resulting purchase intention. The final data set was comprised of 420 responses from 18-35 year old females. A series of ANCOVA analyses were used to determine the effects of possible selves, model idealisation and message frames on consumers’ attitude toward the ad and their purchase intention. The results indicate hoped-for selves, no model advertisements and desired message frames are independently the most effective in the cosmetics context. However, the goal-compatibility hypothesis was not supported. Furthermore, findings indicate an interaction between the image and the message of cosmetics advertising, which suggests cosmetic advertisers must carefully consider the combination of the images and messages they use to promote their brand and products. The theoretical and managerial implications, as well as direction for future research are discussed.

Start-ups face several issues and challenges in the course of their development as a compa-ny. Open innovation has been discussed in research for more than a decade as a concept, which can bring benefits to a company. Even though most of the research has been focus-ing on large enterprises, some researchers discuss also benefits for small companies like start-ups. Nevertheless, it can be observed that some start-ups decide to adopt the opposite of open innovation, namely closed innovation, through not sharing internal knowledge to the outside world. Hence, start-ups perceive the benefits of open innovation differently and decide accordingly whether to adopt open innovation or not. The purpose of this study is to explore if start-ups decide to actually do the former and what reasons they have to do so. Therefore, this study will further discover at what point in the development of their start-up and with whom they adopt open innovation. As an attractive industry for start-ups, the mobile services industry is selected as a scope for this study. Furthermore, Sweden is selected as the country of study, due to its reputation as one of the most innova-tive countries in the world. A qualitative study has been conducted using in-depth interviews with founders and co-founders of start-ups to retrieve narrative stories about their start-up’s development from the first day of an idea to a scalable business, and their experiences and motivations in re-gards to the application of open innovation practices. The analysis of this study detects pat-terns among the interviewed start-ups and concludes that start-ups in the mobile services industry in Sweden adopt open innovation in each phase of their development process. Furthermore, these patterns include several reasons why the start-ups applied open innova-tion practices and with whom, which are changing over the course of their development.