This thesis deals with questions concerning spatial agglomeration of economic activities. The object of study is the Internet industry in central Stockholm. Through the use of statistical data and an interview study the Internet industry is described, measured, and analyzed through theories concerning agglomerations, social network relations, and knowledge and information flows. These theories are interpreted through five agglomeration themes related to the role of customers, subcontractors and partners, competitors, financing, and labour market, respec-tively. The research has recognized the importance of proximity to create and maintain social networks, and to spread information and knowledge, especially tacit knowledge. The thesis also shows how social networks, and information and knowledge flows have an essential role in all the five agglomeration themes that are analyzed. The results of this analysis show that the proximity to customers is the most important factor for the location of the Internet indus-try. Also, the local labour market and access to suppliers and partners are important factors. Competitors and rivals have a role to play when it comes to the diffusion of knowledge and information, although its importance as a location factor is hard to estimate. The analysis of the firms’ financing demonstrate that this factor hardly has been of crucial importance for the location of the Internet industry, but access to (venture) capital might have been of indirect importance for the location and the pace of the development of the Internet industry.

Spray drying is a widely used unit operation for producing particulate products directly from a liquid feed. Important processes that occur inside the spray dryer are droplet formation, droplet drying and interactions between droplets and recycled fines. Various studies have looked at the first two processes, but the latter phenomenon has received less attention. Literature on droplet-particle interaction which aims at quantitatively describing agglomeration in spray drying is scarce and mainly qualitative. For product quality the formation of agglomerates is often desirable. This thesis models and investigates the collisions of individual particles with single droplets. The surface tack of drying droplets has been identified as an important variable for the formation of agglomerates. In this thesis a novel method for measuring tack from the liquid phase has been further improved. The improvements are a more accurate load measurement, an automated control of the tack probe and an improved layout of the sample holder and probe. The key feature of the device is its ability to measure tack of drying droplets, whereas other devices measure tack by wetting a powder. Using our method the tack of a commonly spray dried product, yeast extract, has been measured. From these experiments it was found that with decreasing average moisture content the surface tack increases to a maximum. Below a critical average moisture content the surface of the droplet is dry and the tack rapidly decreases upon further drying. Another important parameter in determining the degree of agglomeration is the degree of penetration. If the particle penetrates the droplet too deeply, the agglomerate structure becomes too dense. To predict the penetration depth, a non-dimensional model has been developed. It describes the penetration of a particle into a liquid droplet during a head-on collision. It is based on a force balance and incorporates surface tension force, viscous force and capillary pressure force. The important parameters determining the collision outcome are the contact angle, the size of the droplet relative to the particle, the Reynolds and Weber numbers. For each contact angle an equilibrium penetration position exists, at this point the surface tension force vector is perpendicular to the penetration direction. Five different penetrations regimes are identified. At low Reynolds numbers, viscous forces dominate and the particle asymptotically travels towards the equilibrium position. Reducing the viscous drag force by increasing the Reynolds number results in initially overshooting the equilibrium position, but the surface tension force pulls the particle back, to attain the equilibrium in an oscillating motion. At even higher Reynolds numbers the particle fully penetrates the droplet, and reaches the centre of the droplet for even higher values for the Reynolds number. The ejection regime is found at high Reynolds number and low Weber numbers and the liquid should be non-wetting. Using the regime maps one is able to identify in which region a spray dryer is operating. Although the full penetration regimes are useful for capturing fines, it should be avoided when agglomeration is desired. The ejection regime should be avoided as well. To validate the model, impact experiments were carried out by dropping glass spheres on the surface of different liquids. These validation experiments were the first attempt to experimentally validate the collision of a single particle with a liquid surface. Besides yeast extract, which has non-Newtonian rheological properties, silicone oils with constant viscosities of 100 mPa•s and 1 Pa•s have been tested. The penetration over time for different impact velocities was determined by analysing high speed camera recordings. The typical penetration times ranged from 0.2 s to 2 s. To obtain accurate location data was recorded at frame rates up to 38 000 frames per second. Glass spheres, with a size of 2 mm were used to allow the visual tracking. Modelling the impacts showed that the model consistently predicted faster penetration times than were observed experimentally. The relative difference increased with increasing viscosity. A parameter fitting exercise showed that better agreement could be obtained by using a higher viscosity and a higher contact angle in the model. With this knowledge the most likely factor influencing the model-experiment mismatch was identified as being the dynamics of wetting of the particle surface. It was also found that using the dynamic contact angle in the model would improve its results. The non-Newtonian characteristics of the yeast extract resulted in the particle rebound and the formation of an air cavity upon impact. The tack measurement technique and penetration model presented in this thesis will be useful tools for the design of spray dryers. Recommendations are made for further model improvement. The experimental validation is the first attempt to validate the presented model. Future improvements are recommended and suggestions are presented.

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: p. 198-203.

Orientador: Eliseu Savério Sposito / Banca: Everaldo Santos Melazzo / Banca: Olga Lucia Castreghini Freitas Firkowski / Resumo: As transformações nos processos de trabalho, no consumo, nas configurações geográficas e no papel do Estado no final do século XX, abrem para uma nova fase do modo de produção industrial, na medida em que altera os pressupostos fordistas de produção. Para lidar com estas transformações, as empresas industriais passaram por processos de reestruturação produtiva, que envolveu as formas de organização da produção, as relações de trabalho, as estratégias espaciais, o papel do Estado etc. Esta pesquisa analisa as particularidades do processo de reestruturação produtiva na indústria de calçados do município de Birigüi-SP e constata que o mesmo esta permeado por mudanças inspiradas no modelo toyotista e por permanências do modelo de produção anterior. Da mesma forma, buscamos entender como surge a indústria calçadista em Birigui bem como suas articulações com o processo de desconcentração industrial no Estado de São Paulo. A história do desenvolvimento industrial na cidade mostrou que se trata de um caso típico de industrialização endógena, porém articulado com o processo de interiorização das atividades econômicas no estado. Por último, verificou-se o desenvolvimento industrial da cidade foi acompanhado pela presença de economias externas, de localização e urbanização / Abstract: The transformations in the working processes, in consumption, in geographical configurations, and in the role of the State at the end of 20th century, open a new phase of the industrial mode of production as they are changing the fordist premises about production. In order to deal with these transformations, industrial enterprises passed by processes of productive restructuring that embraced the organization of production, labor relations, spatial strategies, the role of the State, and so on. This dissertation analyses the particularities of the process of productive restructuring in the shoe industry of Birigui-State of São Paulo, Brazil. We jumped to the conclusion that this process is permeated by changes inspired by toyotist model and by features of the old model. Another goal of this work was to understand how shoe industry begun at the city, and the connections of this economic activity with the process of industrial deconcentration in the state of São Paulo. Our historical research showed that the industrial development of the city is a typical case of endogenous industrialization articulated, however, with the process of interiorization of economic activities at the State of São Paulo. Finally, we verified that the city‟s industrial development was followed by the presence of external economies of location and urbanization / Mestre

The interest in the phenomenon of industrial agglomeration dates back to the late 19th century (particularly, the work of Alfred Marshall). The late 20th century saw a renaissance in this interest, for example, in the ‘new geographical economics’ (e.g. Krugman) and Porter’s framework of competitive forces. Subsequently, clustering has come to be seen as a feature of high technology industries, despite the difficulty to gather empirical evidence to underpin this assertion and to corroborate underlying cluster-related mechanisms that would result in benefits for firms in clustered environments.This thesis extends the discourse on rationales of clustering into the field of the management software industry sector. Its objective is to use the example of the cluster around the German software giant SAP in South-western Germany as a model to explore the strengths and characteristics of clustering in this industry context. A survey-based research design was selected and interview responses were collected from 206 management software firms located throughout Germany. The empirical analysis was based on two complementary statistical approaches. The SAP cluster was compared to two control groups, one consisting of firms from non-clustered regions, the other of firms from other clustered locations. Diversities between environments were analysed using bivariate statistical techniques. The findings of this descriptive analysis substantiate disparities between the SAP cluster and the non-clustered control group. Beneficial effects available to SAP cluster firms can be observed in respect to nearly all factors analysed, i.e. access to specialised human resources, access to investment capital, demand proximity, knowledge spillover externalities, spin-off activity and the accumulation of social capital.This in-depth comparative perspective is complemented through a holistic evaluation employing structural equation modelling. Among the key findings of this analysis are the significant links between location in the SAP cluster and superior growth performance, in which long term professional networks and social capital derived from major software vendors (particularly SAP) act as mediators. Structural equation modelling also highlights a positive effect of being located in the SAP cluster on knowledge spillover externalities, which is mediated by the cultural environment in the SAP cluster. Finally, the SAP cluster environment stimulates spin-off activity, which functions as an important mediator in the accumulation and retention of social capital held with players in the industry. In sum, the empirical analysis suggests that a wide-ranging network of factors exists, in which social capital functions as a catalyst in the mechanisms resulting in benefits available to SAP cluster firms.

No description available.

[pt] O objetivo deste trabalho foi estabelecer uma metodologia de síntese de pós nanométricos a submicrônicos de Y2W3O12, como também relacionar as propriedades óticas, térmicas e mecânicas do Al2W3O12 com métodos distintos de sinterização. As partículas de Y2W3O12 foram obtidas pelo método de co-precipitação reversa modificada mantendo pH constante, com o intuito de manter a supersaturação elevada, garantindo alta taxa de nucleação evitando o crescimento indesejável dos núcleos. As metodologias para cristalização empregadas (tratamento hidrotérmico e calcinação) permitiram obter pós submicrônicos de Y2W3O12 (0.3 ̶ 0.5 Mm) com menor grau de aglomeração em relação ao previamente reportado na literatura. O envelhecimento da dispersão de Y2W3O12 revelou diminuição do tamanho médio de aglomerados em 50 por cento quando comparado à distribuição primária de aglomerados precursores. A dispersão utilizando surfactante CTAB reduziu a aglomeração em 50 por cento. O pó de Al2W3O12 foi sinterizado pelo método de spark plasma sintering (SPS) e comparado com Al2W3O12 sinterizado pelo método de três etapas 1. As propriedades óticas e mecânicas foram estudadas, revelando comportamento distinto entre os materiais consolidados por vias diferentes, evidenciando a importância do método de sinterização sobre a microestrutura final e sobre formação de defeitos pontuais. A espectroscopia de refletância difusa revelou que as amostras obtidas por SPS apresentam absorbância total na faixa da luz visível, sendo coerente com sua coloração preta fosca, assim, a energia de banda proibida dessas amostras situa-se abaixo da energia do espectro visível (EGAP menor que 1,7eV). A amostra sinterizada em três etapas, de coloração branca, possui absorbância parcial no UV-Vis, absorvendo todos os comprimentos de onda até 300nm e conforme o comprimento de onda aumenta e adentra na região visível a absorbância diminui e se torna nula. As amostras de SPS apresentaram ganho expressivo no módulo de Young (80 por cento) e dureza (61-116 por cento) quando comparado com o material obtido por sinterização convencional, previamente descrito na literatura 2, 1. As amostras de SPS quando comparadas com a amostra sinterizada em três etapas 1, apresentou módulo de Young 47 por cento maior e aumento de dureza entre 19-59 por cento, embora, ambas apresentem mesma densidade relativa de 96 por cento, sendo as amostras de SPS com microestrutura de grãos nanométricos proporcionando maior resistência mecânica. O CTE das amostras SPS foi medido, sendo similar ao valor encontrado para a amostra em três etapas 2, constatando que o CTE não foi afetado pela intorução dos defeitos pontuais na Al2W3O12 durante SPS. / [en] The aim of this work is to establish a methodology for the synthesis of submicron nanocomposites of Y2W3O12, as well as to relate the properties, optical and mechanical, of Al2W3O12 with different methods of sintering. The Y2W3O12 particles were obtained by the modified reverse co-precipitation method, maintaining a constant pH along the drip, in order to maintain a high super saturation, ensuring a high nucleation rate, avoiding the undesirable growth of the nuclei. As the methodologies for the crystallization used (hydrothermal treatment and calcination) allowed to obtain post-submicron of Y2W3O12 (0.3 - 0.5 Mm) with lower degree of agglomeration in relation to the report published in the literature. The aging of the dispersion was studied and showed a decrease of 50 percent the average size of agglomerates when compared to the primary distribution of precursor agglomerates. A dispersion using CTAB surfactant reduced 50 percent the agglomeration, as verified by characterization techniques. The Al2W3O12 powder was sintered by the Sintering of Spark Plasma method (SPS) and compared with Al2W3O12 sintered by the three-step method (TSS) 1. The optical and mechanics properties were studied, revealing a differentiated behavior between materials consolidated by different paths, evidencing the importance of the sintering method in a final microstructure. Diffuse reflectance spectroscopy showed that the samples obtained by SPS, it is able to absorb the total wavelengths in the visible light range, being consistent with its black matte color, so the energy gap is below the energy of the spectrum visible (EGAP less than 1.7 eV). The conventional (white) sample absorb all wavelengths up to 300 nm and increasing wavelength decreases absorption and renders it zero. The samples by SPS showed significant gain in the Young s modulus (80 percent) and hardness (61-116 percent) when compared to TSS sample 2, 1. The SPS samples when compared to TSS sample [1], the Young s modulus increased 47 percent and the hardness increased 19-59 percent, although both of them obtained 96 percent relative densities. The reason for the improve of mechanical properties of SPS samples is justified by nanosized grain microstructure providing greater mechanical resistance. The CTE of the SPS samples was measured, being similar to the value found for a three-step sample 2, noting that the CTE was not affected by the introduction of defects in Al2W3O12 after SPS.

A pobreza, em seus aspectos sócio-econômicos, deve ser analisada considerando a ordem de ocupação geográfica, que o modo de vida da população impõe. Na primeira etapa deste trabalho a Nova Geografia Econômica (NGE) é apresentada como um modelo de compreensão desta ordem. Neste modelo, escala, proximidade e liberdade econômica são elementos fundamentais para explicar pujança ou estagnação econômica. A partir desta compreensão, na segunda etapa do trabalho discute-se sobre a pobreza, em particular sobre a mudança de concepção sobre esta para as Ciências Humanas em geral. Ainda nesta etapa comenta-se o caso brasileiro e propõe-se a metodologia do crescimento pró-pobre como uma metodologia aplicável de análise. Por fim, na última parte do trabalho são utilizados dados dos municípios da Região Sul do Brasil e se procede a aplicação de um modelo da NGE, baseando em Hanson (1999) e também faz-se análise do crescimento pró-pobre para todos os municípios da mesma região. O objetivo destes testes é verificar se a validade dos pressupostos da NGE para conforme os dados e o modelo utilizado e também verificar qual a qualidade do crescimento na Região no período entre 1991 e 2000. Os resultados dos testes do modelo da NGE não foram muito significativos, prejudicando conclusões afirmativas. Por outro lado, a análise do crescimento pró-pobre mostrou resultados interessantes: as grandes cidades da região apresentaram crescimento positivo da renda com concentração. Este padrão é um indício a ser investigado mais profundamente para compreender as ligações entre aglomerações e pobreza. / Poverty, in its social and economic aspects, should be analyzed taking into consideration the geographical order that the population’s way of life imposes. In the first part of this study, the New Economic Geography (NEG) is presented as a model to comprehend such order. In its principles, scale, proximity and economic freedom are fundamental to explain boost or stagnation. After that, the second part the discussion is dedicated to poverty, in particular, to how the Human Sciences have changed their conception over this phenomenon. Still in this part of the study the Brazilian case is commented and the pro-poor growth methodology is presented as a tool of analysis. At last, in the third part, a NEG model, based on Hanson (1999), and the pro-poor growth methodology are tested taking counties of the Brazilian South Region as the unity of analysis. The goal is to verify the validity of NEG principles to the data and model being tested. Besides, the other goal is to check on the quality of economic growth in the region from 1991 to 2000. The NEG tests results weren’t much significant, disqualifying strong affirmatives. On the other hand, the pro-poor analysis showed interesting results: the largest cities of the region had all positive but concentrating growth of income. Such pattern should be latterly investigated to better comprehend links of agglomeration and poverty.

Este trabalho tem como objetivo investigar a influência das economias de aglomeração na variação do emprego no setor de calçados no Rio Grande do Sul no período 1998 – 2012. Para tanto utiliza como indicadores de externalidades locais a especialização, diversificação, competição, tamanho médio das firmas e densidade do emprego local. A dimensão geográfica da análise segue a delimitação do arranjo produtivo de calçados identificado pela FEE e inclui os COREDEs Vale do Rio dos Sinos e Paranhana – Encosta da Serra além dos municípios de Picada Café e Nova Petrópolis. O estudo utiliza dados de emprego formal, tamanho e número de empresas da RAIS e área territorial do IBGE. As estimações utilizam dados em painel dinâmico, de efeitos fixos a partir do mecanismo de correção de erros. Os resultados indicam que a especialização afeta negativamente a variação do crescimento do emprego absoluto no curto prazo, porém não é significativa a longo prazo. A diversificação tem relação positiva com o crescimento do emprego ao longo do tempo. O saldo dos indicadores de competição e tamanho médio das firmas aponta que o monopólio local é mais favorável ao setor, ainda que o resultado da competição a longo prazo seja não significativo. Quanto a densidade do emprego, esta recomenda que os fatores locacionais, invés dos setoriais, geram importantes benefícios ao setor. / This study aims to investigate the influence of agglomeration economies on the variation of the employment in the footwear sector of the state of Rio Grande do Sul during the period 1998-2012. To accomplish that goal we use as local externalities indicators the levels of specialization, diversification, competitiveness, and average size of the firms as well as the local employment density. The geographic dimension of analysis follows the delimitation of the footwear cluster identified by the Economics and Statistics Foundation of Rio Grande do Sul (FEE) which includes these regions: COREDE Vale do Rio dos Sinos, COREDE Paranhanda - Enconsta da Serra and also the municipalities named Picada Café and Nova Petrópolis. This study draws on data of formal employment, size and number of enterprises that are listed in the federal administrative database named RAIS. The territorial area is defined as IBGE indicates. The estimations are performed based on a dynamic panel of fixed effects using errors correction mechanism. The results indicate that specialization affects in a negative way the growth rate of absolute employment in the short run, although this evidence is not significant in the long run. The diversification is positively related to the employment growth over time. The balance of the competitiveness indicators and average size of the enterprises points out that the local monopoly benefit the sector, although the competitiveness results has not been found significant in the long run. Regarding the employment density, it is indicated that locational factors, instead of the sector’s ones, generate important benefits to the sector.

Diploma thesis resulted from a part of the experimental project of the department of geography ? Pedagogical Faculty, University of South Bohemia in České Budějovice, which was supported with the grant agency sb. u. (grant no. 072/2010/s). It discusses the problems of suburbanization in the agglomeration of České Budějovice, specifically the suburbs of the southern and south-western sectors. Exploration included various aspects of suburban geography, where there were elaborate social, economic and demographic problems. I observe suburban transformation from the socialist and post-socialist period to the present. Due to the complex problems of the topic, three main aims were identified to reflect the substance of the work. To achieve them, the literature review revealed useful information and thematic maps were created. Data was collected in the chosen localities and analysis of dates, terrain mapping, dialogues and examinations with mayors of the municipalities were carried out. The theoretical part describes chosen characterizations of the social-geographical world, for example inhabitants, industry, agriculture, services, travelling and transport. The following chapters discuss aspects of the exploration of suburbanization, according to theories and literature. They explain reasons and conditions of suburban actions in the worlds? developed countries, suburbanization in the U. S. A. and in the western and post-socialist Europe. The practical part of the work used quantitative research, included collecting data about the typology of the seats, analysis of the development of inhabitants in suburban municipalities, the age of the permanently inhabited houses, number of built flats, processions and another problems in the suburbs. The results of this research can be used as a resource for information about the suburban development of smaller towns. The work is able to serve not only as informative material for the mayors of individual municipalities but is also able to help the municipal authorities of České Budějovice.