As relações socioespaciais interurbanas transformaram-se com o passar do tempo, mas é no século XX com a industrialização e a aceleração da urbanização que esse processo alcança um novo patamar. Especificamente no caso brasileiro, essas transformações se tornam mais significativas a partir dos anos 1950, quando expressivos crescimentos demográficos e expansões territoriais são vistos nos núcleos urbanos do país. Nesse processo, ocorre a aproximação entre cidades vizinhas, que ao estreitarem seus vínculos passam a ter fortes relações de interdependência e complementariedade entre si, formando um minissistema urbano único, com características próprias que ultrapassa a divisão político-administrativa municipal, conhecido como: aglomerações urbanas. Hoje, mais da metade da população brasileira vive em áreas aglomeradas que, por sua vez, vêm se tornando cada vez mais dinâmica e complexa. Frente a esse cenário, esse trabalho busca contribuir no estudo das aglomerações urbanas, analisando como elas afetam configuracionalmente as cidades que a compõem através de diferentes recortes espaciais. O trabalho é desenvolvido a partir de uma abordagem configuracional, entendendo que o espaço urbano é formado por células conectadas ente si, permitindo que o tema seja explorado de forma quantitativa através da modelagem. A pesquisa analisa características de proximidade e atratividade nas cidades de Bento Gonçalves, Garibaldi e Carlos Barbosa (Serra Gaúcha/RS), através do cálculo de indicadores espaciais destes locais. Como método de análise é feita a comparação dos resultados obtidos nos diferentes recortes espaciais (cenários) da área de estudo, que representam as diferentes escalas em que o fenômeno atua, agregando aos dados espaciais, informações socioeconômicas das localidades. Os resultados obtidos sugerem a redistribuição dos valores das medidas calculadas nas diferentes escalas consideradas, indicando a variação da hierarquia das porções de espaços que compõe as cidades aglomeradas nos diferentes cenários estudados. Já a metodologia aplicada se demonstrou como uma eficiente ferramenta de exploração do tema, contribuindo no entendimento e planejamento urbano de cidades aglomeradas. / Interurban socio-spatial relationships have changed over time, but in the twentieth century, with industrialization and the acceleration of urbanization, this process reaches a new level. Specifically in the Brazilian case, these transformations have become more significant since the 1950s, when expressive demographic growth and territorial expansion are seen in the urban centers of the country. In this process, neighboring cities approached each other and, by doing so, by doing so, tighten bonds, develop strong relations of interdependence and complementarity between them, forming a unique urban mini-system with its own characteristics that goes beyond the municipal political-administrative division, known as urban agglomerations. Today, more than half of the Brazilian population lives in agglomerated areas that are becoming increasingly dynamic and complex. In this scenario, this work seeks to contribute to the study of the urban agglomerations' theme, analyzing them through different spatial subsets. The work is developed from a configurational approach, understanding that the urban space is formed by cells connected to each other, allowing the theme to be explored quantitatively through modeling. The research analyzes characteristics of proximity and attractiveness in the cities of Bento Gonçalves, Garibaldi and Carlos Barbosa (Serra Gaúcha / RS), through the calculation of spatial indicators of these sites. As a method of analysis, the results obtained in the different spatial subsets (scenarios) of the study area are compared, representing the different spaces in which the phenomenon acts, adding to the spatial data, socio-economic information of the localities. The conclusion suggests the redistribution of the measures' values calculated in the different scales considered, indicating the variation of the spaces' hierarchy that compose the cities agglomerated in the different scenarios. The applied Methodology proved to be an efficient tool for exploring the theme, contributing to the understanding and urban planning of agglomerated cities.

Esta dissertação tem como objetivo investigar as externalidades positivas geradas pelas regiões diversificadas através de uma análise dos serviços de Tecnologia da Informação (TI) presentes na Região Metropolitana de São Paulo (RMSP). Ou seja, busca apresentar os elementos da diversificação e evidenciar as formas como essas vantagens se manifestam no ambiente. Essa análise se fundamenta no pressuposto de que tais espaços devem ser entendidos de forma distinta dos ambientes especializados, já estudados no Brasil. Nos ambientes diversificados as formas mais importantes de transferência de conhecimento estão fora da indústria. Nessas localidades, a heterogeneidade promove benefícios que incluem: oportunidades para imitar, compartilhar e recombinar ideias e práticas através da indústria e a possibilidade de troca e fertilização cruzada de ideias. Além disso, o melhor funcionamento da infraestrutura, a proximidade dos mercados, o acesso aos serviços especializados são fatores adicionais que geram benefícios para os agentes. Dentro desses ambientes o contato face a face é um dos elementos fundamentais para o entendimento dessas regiões. O contato face a face é uma forma de tecnologia de comunicação que resolve problemas de incentivos, confiança e socialização. Esse contato, além de transferir conhecimento, permite observar e selecionar indivíduos. Adicionalmente, um fenômeno importante da análise das regiões diversificadas são as buzz cities. Estas são cidades com grande diversidade produtiva e social, altamente urbanizadas. Essas cidades colocam indivíduos qualificados em contato uns com os outros. Dessa forma, para atingir o objetivo proposto dois passos foram realizados. Em primeiro lugar, foi apresentada uma revisão sobre as principais características de formação e desenvolvimento das atividades de serviços de TI no Brasil, conjuntamente com um levantamento de informações e dados sobre o setor. Essa análise permitiu observar uma forte concentração das atividades na microrregião de São Paulo. A concentração das atividades de TI é entendida como parte do processo de formação histórica da indústria. No Brasil, as atividades de TI se desenvolveram a partir da associação com os setores econômicos que demandavam capacitações tecnológicas cada vez mais complexas de seus fornecedores. Em segundo lugar, foi realizada uma pesquisa de campo com o propósito de evidenciar algumas das principais vantagens da diversificação industrial. A partir dos resultados alcançados observa-se a presença de externalidades próprias da diversificação industrial, que envolvem trocas de conhecimento entre diferentes agentes e possuem importantes implicações para empresas, como as oportunidades de acesso à mão de obra especializada e altamente concentrada na região e as redes de relacionamentos geradas entre as empresas de TI, os usuários e os fornecedores de tecnologia. Nesses ambientes, o contato face a face é um dos fatores fundamentais para a consolidação das empresas em um mercado altamente pulverizado, que envolve conhecimentos complexos. Além disso, percebe-se que as buzz cities geram importantes elos para a consolidação das empresas, fazendo com que as forças de aglomerações sejam reforçadas pela transmissão de conhecimento intersetoriais. / This master dissertation aims to investigate the positive externalities generated by the diversified regions through an analysis of the Information Technology Services (IT) in Metropolitan Region of São Paulo (MRSP). In other words, it seeks to present the elements of diversification and highlight the ways in which these advantages are manifested in the environment. This analysis is based on the assumption that such spaces must be understood differently of specialized environments, already studied in Brazil. In diverse environments, there is the idea that the most important forms of knowledge spillovers are outside the industry. In these locations, the heterogeneity promotes benefits that include: opportunities to imitate, to share and to recombine ideas and practices across the industry, and the possibility of exchange and cross-fertilization of ideas. Moreover, the better functioning of infrastructure, proximity to markets, and access to specialized services are additional factors that generate benefits for agents. Within these environments, face to face contact is a key element for the understanding of these regions. Face to face contact is a form of communication technology that solves problems of incentives, confidence and socialization. This contact, beyond transferring knowledge, allows to observe and to select individuals. Additionally, an important phenomenon of analysis of diversified regions is the buzz cities. These are cities with large production and social diversity, highly urbanized. These cities places qualified individuals in contact with each other. Thus, to achieve the proposed goal two steps were performed. Firstly, a review of the main features of formation and development of IT in Brazil, together with a data about the sector was presented. This analysis allowed us to observe a large concentration of activities in the microregion of Sao Paulo. The concentration of IT activity is understood as part of the industrial formation historical process. In Brazil, the IT activities were developed from the association with economic sectors that demand increasingly complex technological capabilities. Secondly, a field research was performed, in order to highlight some of the major advantages of industrial diversification. From the results obtained it is possible to observe the presence of externalities diversification, involving knowledge exchange between different agents and important implications for businesses, such as the opportunities for access to skilled labor highly concentrated in the region and the networks generated between IT companies, users and technology providers. In these environments, the face to face contact is one of the key factors for the consolidation of IT companies in a highly fragmented market, which involves complex knowledge. Furthermore, in the buzz cities are produced important links to the consolidation of companies, strengthening the forces of clusters through inter-industry knowledge spillovers.

A aglomeração de partículas é um processo muito usado na indústria, que permite melhorar as propriedades de instantaneização de produtos em pó sem alterar suas características nutricionais e sensoriais. O objetivo deste trabalho foi realizar o processo de aglomeração de partículas de farinha de banana verde com alto conteúdo de amido resistente, usando um leito fluidizado pulsado avaliando seu efeito sobre as características finais da farinha, para ser usada como ingrediente funcional na melhora do índice glicêmico e níveis de insulina plasmática no sangue. A matéria prima usada foi farinha de banana verde com alto conteúdo de amido resistente e um leito fluidizado, constituído com um sistema de pulsação proporcionado por uma válvula de esfera, trabalhando à frequência de 600 rpm. Solução de alginato de sódio (5 g/100 g, a 35°C) foi usada como agente ligante na atomização a uma vazão de 3,0 mL/min. As condições de processamento como temperatura, pressão, vazão de ar, e tempo total de processo, foram mantidas em 95°C, 1,0 bar, 0,3 m/s, 50 min., para amostras de 400 g. Resultados após o processo de aglomeração indicam que houve uma diminuição do teor de umidade, aumento do diâmetro médio das partículas e do índice de fluidez, assim como elevada porosidade da partícula com forma irregular, características decorrentes de um produto aglomerado. A farinha aglomerada apresentou conteúdo de amido resistente de 53,95 ± 0,22 % em comparação a 57,49 ± 0,43 % na matéria prima. Pode-se concluir que o processo de aglomeração não alterou as propriedades funcionais da farinha de banana verde mantendo os níveis do AR, resultando na melhora das propriedades de instantaneização das partículas e dispersão em água. / The powder agglomeration process is widely used in food industry, due to increases the instant properties, rapidly dissolving in liquids without altering their nutritional and sensory characteristics. The aim of this study was to assess the particle agglomeration process of the green banana four (GBF) with high resistant starch (RS) content, using a pulsed fluidized bed and evaluating its effect on the final characteristics of flour, to be used as a functional ingredient in improving glycemic and plasma insulin levels in the blood. It was used samples of 400 g of GBF and a fluidized bed constituted with a pulsation system provided by a sphere valve, working at frequency of 600 rpm. Solution of sodium alginate (5 g/100 g, 35°C) was used as the binder in the spray at a rate of (3.0 mL/min). The processing conditions such as temperature, pressure, air flow and total process time were maintained at 95°C, 1.0 bar, 0,3 m/s and 50 min. As results, they were seen a reduction of moisture content, an increase of average particle diameter, high flowability and porosity with irregular shape, typical characteristics from an agglomerated product. The agglomerated flour has RS content of 53.95 ± 0.22 % in comparison to 57.49 ± 0.43 % to the original content. In conclusion, the agglomeration process did not affect the functional properties of green banana flour, maintaining levels of resistant starch, and results in an improvement in the instant properties of the particles and dispersibility in water.

Nanoparticles have gained growing attention of the scientific community over the past few decades due to their high potential to be used in diverse industrial applications. Nanoparticles often possess superior characteristics, such as catalytic activity, photochemical activity, and mechanical strength, compared to their bulk counterparts, making them more desirable in different industrial applications. During the past few decades, the use of the nanoparticles in various industries has been increased. With increasing usage release of nanoparticles into the environment has also increased. There is a growing concern about the nanoparticle toxicity and numerous studies have shown the toxic effects of different nanoparticles on various plants, animals, and microorganisms in the environment. Toxicity of nanoparticles is often attributed to their morphology and their ability to undergo different transformations in the environment. These transformations include aggregation, dissolution, and surface adsorption. Natural organic matter (NOM) are the most abundant natural ligands in the environment which include Humic acid and Fulvic acid. These high molecular weight organic molecules have complex structures and contain many different functional groups such as carboxylic acid groups, hydroxyl, amino and phenolic groups that can interact with the nanoparticle surface. The nature and the intensity of the interaction are dependent on several factors including the size and the surface functionality of nanoparticles and pH of the medium. The smaller the nanoparticle, the higher the adsorption of NOM due to the high surface to volume ratio of smaller particles. Functional groups on the surface dictate the surface charge of the nanoparticles in water depending on the acidity. The higher the acidity, higher the adsorption of NOM due to increased electrostatic attractions between positively charged nanoparticles and the negatively charged NOM molecules. Adsorbed NOM on nanoparticles affect the other transformations such as aggregation and dissolution and can in turn alter the reactivity and toxicity of the nanoparticles. Therefore, effect of NOM is an important factor that should be considered in environmental toxicity related studies of nanoparticles.

As the attention of ethnic restaurants grow from consumers, researchers have questioned the proper assessment of identifying ethnic restaurant consumer demand and where ethnic restaurants should locate accordingly. For this reason, past literature has focused on demographic features to answer these questions. However, unlike non-ethnic restaurant demand, ethnic restaurant demand cannot be fully explained by demographics since the demand for ethnic restaurants consist of two major groups, which are non-ethnic and ethnic consumers. The two consumer groups differ in location, which ethnic consumers are clustered while other non-ethnic consumers are spread across the geographical plain. The two consumer groups also differ in acceptance which ethnic consumers have a pre-established notion of the ethnic restaurant theme while non-ethnic consumers require acceptance to consume. This study proposes that since ethnic restaurants have these differences ethnic restaurants show difference in clustering patterns. More specifically this study attempts to identify whether higher acceptance from non-ethnic consumers allow ethnic restaurants to expand to other non-ethnic consumer regions while ethnic restaurants are mostly clustered in ethnic communities. In addition, the study further investigates whether ethnic restaurant clustering patterns differ by its restaurant price segment. The empirical results of this study show that acceptance of ethnic food, general restaurant opinion, and country of origin plays a crucial role in ethnic restaurants to diffuse to non-ethnic consumers while ethnic restaurants agglomerate near ethnic communities. However, higher price restaurants were found cluster stronger than lower price restaurants to reduce search cost for consumers which confirms previous studies. Finally, this study found that acceptance of food and general restaurant opinion from non-ethnic consumers affects ethnic restaurants in the ethnic community to diffuse but acceptance of country of origin showed ethnic restaurants in ethnic communities to cluster which suggest that cultural aspects allow ethnic restaurants to cluster stronger in ethnic communities.

It is important for any country to understand why its population makes certain choices on where to locate, since it can help to guide policy aimed at reviving deprived areas. Over the past few decades there has been a general trend for the population to migrate from the North to the South in England and Wales. Similarly, there has been an imbalance in the spread of new opportunities, with advanced services tending to locate in the South, particularly close London. This paper investigates whether changing employment patterns, away from manufacturing and towards services, has helped to facilitate migration within the England and Wales. There has been a distinct lack of empirical analysis in this area due to data limitations. Prior studies have had to utilise broad geographic regions in their analysis, providing limited insight into the reasons for such change. This paper aims to expand on these studies by looking at data on a more local level. This study made use of fixed panel regressions in order to estimate the effects of a region’s employment structure upon migration rates. The results indicate that neither the sector of employment, nor unemployment rates directly influence an individual’s likelihood to migrate. However, there is evidence to support the idea that population density influences migration, potentially as a result of agglomeration economies.

During the past decades, the establishment of external shopping centers have been increasing, causing debates on how they affect the viability and vitality of city centers. Instead of studying them as individual actors that are in competition with each other, it is interesting to examine them as components that together make cities complete trading destinations.  The purpose of this thesis is to study the coexistence and collaboration between different retail agglomerations. Retail agglomeration attributes are implemented to distinguish existing strengths and weaknesses for each trading venue, in order to identify where they complement each other. The research method is qualitative with an abductive approach. Six semi-structured interviews were conducted with respondents who represent different associations.  The findings of the research revealed that city centers and external shopping establishments are able to coexist if they complement each other through their individual offerings and experiences. Different retail agglomerations attract contrasting customer groups, allowing them to coexist. Collaboration between retail agglomerations can be implemented in several ways and can enhance the attractiveness of cities as trading destinations. The collaboration can occur by implementing shared marketing, shuttle bus services or collective events.  This research is limited to only investigating one medium sized city and three retail agglomeration formats. Furthermore, the choice of participants did not include consumers and store owners, which could have provided additional perspectives. The findings contribute to the study field by highlighting how retail agglomerations can coexist and collaborate and can be useful for other medium sized cities.

The characterization of fine particles is an area of immense significance to many industrial endeavors. It has been estimated that 70% of all industrial processes deal with fine particles at some point in the process. A natural phenomenon occurring in these processes is colloidal aggregation. This study examines aggregation in colloidal systems in order to characterize, examine, and control this occurrence in industrial processes. The study of particle aggregation has been broken into many different areas, such as collision mechanisms, interaction energy etc, but a complete model that integrates these different aspects has never been fully realized. A new model is required to accurately predict the aggregation behavior of colloidal particles. In this work, a new model is developed that integrates Smoluchowski kinetics, total interaction energy between particles, and stability ratios for perikinetic and orthokinetic collision mechanisms. The total particle interaction energy necessary for the calculation of stability ratios is represented by the summation of electrostatic and van der Waals interactions. The electrostatic interactions are modeled using DLVO theory, the linear Poisson-Boltzmann equation, and a numerical solution for the non-linear Poisson-Boltzmann Equation, while the van der Waals interactions are represented by Hamaker theory. The mathematical model is solved using an adjustable discretion technique, which is tested against a specific analytic solution, and yields an assessment of the error intrinsic in the discretization method. The basis of the mathematical model is a population balance framework. The model developed in this study is general in many respects, but could be readily applied to many different aggregation systems with minor modification. A comparison of the mathematical model with previous experiments conducted by Scott Fisher (1998) is carried out for the perikinetic and orthokinetic transport-limited aggregation regimes. The fractal nature of solid-sphere aggregates is considered when comparing the mathematical model predictions with experimental measurements. The previous experiments that are used for comparison utilized polystyrene particles ranging from 100 nm to 500 nm in initial diameter, several initial particle concentrations, and various stirring rates. Zeta potential measurements are presented in order to set the range of transport-limited aggregation. An assessment of the results of the mathematical model with the experimental results show good agreement for transport-limited aggregation within the perikinetic and orthokinetic transport-limited aggregation, with average particle sizes ranging from 100 nm to well over 2 microns.

The purpose of this research is to demonstrate the ability to generate and characterize a nanometer sized aerosol using solutions, suspensions, and a bulk nanopowder, and to research the viability of using an acoustic dry aerosol generator/elutriator (ADAGE) to aerosolize a bulk nanopowder into a nanometer sized aerosol. The research compares the results from a portable scanning mobility particle sizer (SMPS) to the more traditional method of counting and sizing particles on a filter sample using scanning electron microscopy (SEM). Sodium chloride aerosol was used for the comparisons. The sputter coating thickness, a conductive coating necessary for SEM, was measured on different sizes of polystyrene latex spheres (PSLS). Aluminum oxide powder was aerosolized using an ADAGE and several different support membranes and sound frequency combinations were explored. A portable SMPS was used to determine the size distributions of the generated aerosols. Polycarbonate membrane (PCM) filter samples were collected for subsequent SEM analysis. The particle size distributions were determined from photographs of the membrane filters. SMPS data and membrane samples were collected simultaneously. The sputter coating thicknesses on four different sizes of PSLS, range 57 nanometers (nm) to 220 nm, were measured using transmission electron microscopy and the results from the SEM and SMPS were compared after accounting for the sputter coating thickness. Aluminum oxide nanopowder (20 nm) was aerosolized using a modified ADAGE technique. Four different support membranes and four different sound frequencies were tested with the ADAGE. The aerosol was collected onto PCM filters and the samples were examined using SEM. The results indicate that the SMPS and SEM distributions were log-normally distributed with a median diameter of approximately 42 nm and 55 nm, respectively, and geometric standard deviations (GSD) of approximately 1.6 and 1.7, respectively. The two methods yielded similar distributional trends with a difference in median diameters of approximately 11 - 15 nm. The sputter coating thickness on the different sizes of PSLSs ranged from 15.4 - 17.4 nm. The aerosols generated, using the modified ADAGE, were low in concentration. The particles remained as agglomerates and varied widely in size. An aluminum foil support membrane coupled with a high sound frequency generated the smallest agglomerates. A well characterized sodium chloride aerosol was generated and was reproducible. The distributions determined using SEM were slightly larger than those obtained from SMPS, however, the distributions had relatively the same shape as reflected in their GSDs. This suggests that a portable SMPS is a suitable method for characterizing a nanoaerosol. The sizing techniques could be compared after correcting for the effects of the sputter coating necessary for SEM examination. It was determined that the sputter coating thickness on nano-sized particles and particles up to approximately 220 nm can be expected to be the same and that the sputter coating can add considerably to the size of a nanoparticle. This has important implications for worker health where nanoaerosol exposure is a concern. The sputter coating must be considered when SEM is used to describe a nanoaerosol exposure. The performance of the modified ADAGE was less than expected. The low aerosol output from the ADAGE prevented a more detailed analysis and was limited to only a qualitative comparison. Some combinations of support membranes and sound frequencies performed better than others, particularly conductive support membranes and high sound frequencies. In conclusion, a portable SMPS yielded results similar to those obtained by SEM. The sputter coating was the same thickness on the PSLSs studied. The sputter coating thickness must be considered when characterizing nanoparticles using SEM. Finally, a conductive support membrane and higher frequencies appeared to generate the smallest agglomerates using the ADAGE technique.

Granulation is an industrial process where fine particles are bound together into larger granules. The process has numerous applications including the manufacture of pharmaceuticals and the production of cosmetics, chemicals, detergents and fertilisers. This thesis studies aspects of wet granulation which involves the application of a viscous binder, usually in the form of a spray, to an agitated bed of powder particles. Individual powder particles may adhere together, joined by small quantities of binder fluid called liquid bridges. By a process of collision and adherence additional particles may join the newly formed agglomerates. Agglomerates may also coalesce together which is a process that leads to granule formation. On the completion of this process, granules are typically dried.This thesis studies wet granulation on three different levels. First, micro-level investigations of liquid bridges between two and three particles are performed. For the two-particle case, the fluid profile of static (stationary) and dynamic (moving) liquid bridges is investigated. For the static case, a numerical solution to the Young-Laplace equation is obtained; this relates the volume of binder fluid to liquid bridge properties such as the inter-particle force. An analytic solution is also obtained, providing the liquid bridge profile in terms of known mathematical functions. For both solutions, the radii of the (spherical) primary particles may be different. The dynamic case is then studied using the Navier-Stokes equations with the low Reynolds number approximation. The motion of the approaching particles is shown to be damped by the viscosity of the liquid bridge. Static liquid bridges between three equally sized primary particles are then studied. Symmetry of the problem is used to obtain a numerical solution to the Young-Laplace equation. Liquid bridge properties are calculated in terms of the binder fluid volume. Experimental agreement is provided.Secondly, a model to estimate the stickiness (fractional wet surface area) of agglomerates is proposed. Primary particles are approximated as spheres and are added one at a time in a closely packed arrangement. The model includes parameters to control the inter-particle separation distance and the fluid saturation state. Computational geometry is used to obtain results which relate the number of particles and the volume of binder fluid to the stickiness of the agglomerates.Finally, a population balance model for wet granulation is developed by extending an earlier model to incorporate the effects of binder fluid. Functions for the inter-particle collision rate and drying rate are proposed, including functions which are derived from the geometric model, described above, for the case of maximum particle consolidation. The model is solved numerically for a range of coalescence kernels and results are presented which show the effect of binder volume and the drying rate.