Made available in DSpace on 2016-03-15T19:30:45Z (GMT). No. of bitstreams: 1 Victor Wolowski Kenski.pdf: 834953 bytes, checksum: 834b9a918736078741723efd903bb181 (MD5) Previous issue date: 2011-08-16 / Fundo Mackenzie de Pesquisa / Small technology-based startup companies need to obtain a set of resources to establish themselves in the market and obtain a competitive advantage. They usually draw on external sources of support and financing to obtain these resources. This research is about startups which drew on the Innovative Program for the Small Enterprise (PIPE), granted and managed by the São Paulo Research Foundation (FAPESP). The goal is to analyze the way they developed a competitive advantage, the strategies they adopted and the importance of PIPE in this process. The research investigates the starting conditions, the evolution with the new resources and the situation that ensued from the creation of the competitive advantage. Ten companies were studied through a simple qualitative research based on interviews with their managers. The results show that the performances varies with the resources obtained by partners in the company s early days and with the capabilities to search the remaining resources and harmonically integrate them to the existing ones. They also show the positive influence of PIPE in obtaining the required resources and generating competitive advantages. / As pequenas empresas de base tecnológica em início de operação necessitam completar um conjunto de recursos para conseguir se estabelecer no mercado e obter uma vantagem competitiva. Elas em geral recorrem a fontes externas de apoio ou financiamento para suprir essa necessidade. Essa pesquisa trata de empresas que recorreram ao Programa Inovativo da Pequena Empresa (PIPE) concedido e administrado pela Fundação de Amparo à Pesquisa no Estado de São Paulo (FAPESP). O objetivo é o de analisar a forma como desenvolveram vantagens competitivas, as estratégias adotadas e a importância do PIPE nesse processo. São apresentadas as condições de partida, a evolução com os recursos aportados e a situação posterior à criação da vantagem competitiva. Dez empresas foram estudadas por meio de uma pesquisa qualitativa simples baseada em entrevistas com seus dirigentes. Os resultados mostram que os desempenhos variam de acordo com os recursos trazidos pelos sócios ainda na fundação e com as capacidades de buscar recursos faltantes e integrá-los de forma harmônica aos já existentes. Os resultados mostram uma influência positiva do PIPE no processo de completar os recursos e gerar uma vantagem competitiva.

Este trabalho apresenta um estudo sobre o comportamento de tubos metálicos enterrados, submetidos ao carregamento móvel de um veículo. Foram realizadas análises numéricas utilizando o método de elementos finitos para o cálculo da tensão vertical no solo, momento fletor, tensão normal e deformação diametral vertical do tubo. Foram analisados 630 modelos, obtidos da variação das características do solo (módulo de elasticidade) com o objetivo de representar diferentes níveis de compactação do solo, características do tubo (espessura da parede do tubo) e da altura da camada de recobrimento do solo. O programa utilizado nas análises numéricas foi o SIGMA/W do pacote Geostudio. Os resultados encontrados apontam que as maiores tensões no solo, momentos, tensões normais e deformações no tubo ocorrem devido ao carregamento móvel quando este se localiza exatamente acima do tubo. Observou-se que o aumento da espessura da camada de solo que recobre a tubulação causa uma diminuição de 15% a 55% das tensões verticais no solo, momentos fletores, tensões normais e deformações no tubo. Foram desenvolvidas equações para o cálculo das deformações para os casos estudados. Foi também desenvolvido um procedimento para a moldagem de corpos de prova de areia no estado fofo (índice de vazios máximo) para realização de ensaios triaxiais. / This paper presents a study on the behavior of buried metal pipes, subjected to the vehicle live load. Numerical analysis using the finite element method to calculate the vertical stress were made on the ground, bending moment, normal stress and diametral vertical pipe deformation. 630 models were analyzed, obtained from the variation of the soil characteristics (modulus) in order to represent different levels of soil compaction, the pipe characteristics (thickness of the pipe wall) and the height of the soil cover layer. The program used in numerical analysis was the SIGMA/W Geostudio package. The results show that the highest stresses on the ground moments, normal stresses and strains in the tube occur due to live loading when it is located just above the tube. It was observed that increasing the thickness of the layer of soil covering the pipe causes a decrease from 15% to 55% of the vertical tensions in the ground, bending moments, normal stress and strain on the pipe. Equations were developed to calculate the deformations in the cases studied. It has also developed a procedure for molding sand specimens into the soft state (maximum void ratio) to perform triaxial tests.

[pt] O presente trabalho trata do desenvolvimento de uma modelagem numérica para estruturas cilíndricas com materiais compósitos. Uma classe especial de materiais compósitos, os materiais com gradação funcional (FGM), também é investigada. O modelo constitutivo adotado para o material compósito é baseado na regra das misturas. Esta metodologia é aplicada na análise de reparo e reforço de dutos, considerando as solicitações usuais de campo, notadamente as decorrentes da variação de temperatura e das pressões internas, bem como os efeitos da interação solo-estrutura. O sistema duto-reforço é modelado como elemento de viga conforme o método dos elementos finitos, e as tensões na seção são integradas numericamente. Para tanto, o material, tanto do duto quanto da camada de reforço, é admitido com comportamento elastoplástico. Alguns exemplos, simulando as condições típicas, são apresentados e discutidos, de maneira a avaliar o comportamento dos dutos recuperados com materiais compósitos, e a propor a solução mais eficiente no dimensionamento da camada de reforço, inclusive em termos do material com gradação funcional. / [en] This work presents a numerical model for the investigation of pipe constituted by composite materials. A special class of composite materials, functionally graded materials (FGM), is considered. The composite material model is based on the rule of mixture and an elastoplastic material behavior is incorporated. A finite element model based on the beam element discretization is employed, by which the section integration allows the representation of the non-linear material behavior. This methodology is applied to the analysis of reinforced and repaired pipelines. The soilstructure interaction, accomplished through transversal and longitudinal springs, besides transversal, axial and pressure loading are incorporated. Some examples, simulating the conditions in field, are shown and discussed in order to evaluate the behavior of reinforced pipes, proposing the soluction more efficient in modeling of the reinforcement, included in terms of the functionally graded materials .

The small village Chonyonyo, in the district Karagwe in the northwest of Tanzania has a shortage of safe drinking water. Women and children spend several hours a day fetching water and gathering firewood to boil the water to make it more suitable for drinking. The need of new sustainable water supply solutions is fundamental for providing more people with safe drinking water.   Two water distribution alternatives was suggested by Engineers Without Borders and MAVUNO as possible solutions to supply the community with water.  Alternative 1 consisted of a 10 km distribution system from an already existing groundwater well at the MAVUNO office to Chonyonyo. Alternative 2 consisted of a 3.5 km distribution system from the most neighboring valley to Chonyonyo, where no groundwater well exists today. Both alternatives would be powered by solar panels and operated six hours a day. The most sustainable distribution solution was chosen by modeling the distribution alternatives in the modeling software EPANET. Input parameters to simulate the model were position, elevation and dimension of storage tanks and pipes. Other required input parameters were absolute roughness, water withdrawal, operation hours, description of the withdrawal pattern for the water outlet and other modelling conditions such as a suitable simulation time. The selection of water distribution system was based on minimum requirements of energy used for operation weighed with lowest possible water residence time in the storage tank. Water quality analyses of the raw water source for distribution alternative 1 were performed in order to classify the water and select suitable water treatment solutions. The analyses consisted of microbiological and metal/metalloid analyses, and measurements of EC and pH. The result of the simulation showed that neither of the distribution alternatives met all the pipe design criteria. The main reason is that the system can not be constantly operated. If this criterion is excluded the optimal solution is distribution alternative 1 with an outer pipe diameter of 110 mm throughout the whole distribution system and a water residence time in the storage tank of 57.1 hours. The water quality analysis showed that the ground water source for distribution alternative 1 was affected by surface water and is thus classified as unusable because of high levels of harmful bacteria and lead. The most suitable water treatment solution due to the aspects of sustainable water supply are the microbiological barriers ultrafiltration and UV-light in combination with a treatment method to remove lead from the water. / I samhället Chonyonyo i distriktet Karagwe i nordvästra Tanzania råder brist på säkert dricksvatten. Kvinnor och barn spenderar flera timmar om dagen för att hämta vatten och samla ved för att koka vattnet så att det blir säkrare att dricka. Behovet av nya hållbara vattenlösningar är fundamental för att kunna försörja fler människor med säkert dricksvatten.   Två vattendistributionsalternativ lades fram av Ingenjörer utan gränser och MAVUNO som möjliga lösningar för att försörja invånarna i Chonyonyo med dricksvatten. Alternativ 1 bestod av ett 10 km distributionssystem från en befintlig grundvattenbrunn vid MAVUNO:s kontor. Alternativ 2 bestod av ett 3.5 km distributionssystem från den närmaste dalen till samhället Chonyonyo, där det inte finns någon befintlig grundvattenbrunn. Båda alternativen kommer att drivas av solpaneler och vara under drift sex timmar per dygn. Det lämpligaste distributionsalternativet valdes ut genom simulering i mjukvaran EPANET. Ingångsparametrar för simuleringen var bl.a. position, höjd och dimension på reservoarer och ledningar. Ytterligare nödvändiga parametrar var skrovlighet på ledningar, storlek på vattenuttag, antal driftstimmar, uttagmönster från vattenkranar i systemet samt andra modelleringsförhållanden såsom en lämplig simuleringstid. Valet av distributionssystem grundades på lägsta möjliga energibehov för drift viktat mot lägsta möjliga uppehållstid i vattenreservoarerna.   Kvalitetsanalyser av råvattnet för distributionsalternativ 1 genomfördes för att klassificera vattnet och göra lämpliga val av vattenreningslösningar. Analyserna omfattade mätning av ett antal mikrobiologiska parametrar, metaller/metalloider samt EC och pH. Simuleringen visade att ingen av alternativen kunde uppnå alla designkriterierna. Huvudorsaken till det är att systemet endast är i drift periodvis. Bortsett från dessa kriterier var det optimala lösningen distributionsalternativ 1 med en yttre rördiameter på 110 mm genom hela systemet med en maximal uppehållstid i vattenreservoaren på ca 57 timmar.   Analyserna visade att grundvattnet var ytvattenpåverkat och klassificeras som otjänligt med höga nivåer av skadliga bakterier och bly. De lämpligaste vattenreningslösningarna i förhållande till hållbarhetsaspekterna var de mikrobiologiska barriärerna ultrafiltrering och behandling med UV-ljus kombinerat med en reningsmetod för att avskilja bly från vattnet.

Mixing of backfill of the pipe drain construction with sub-ballast layer material through using enclosed drainage systems (mostly by pipe drains) has to be prevented. In order to do so, regulation SŽDC S4 Železniční spodek provides a filtration criterion which needs to be fulfilled or a geotextile with filtration function has to be used. This master thesis verifies if filtration criteria are fulfilled in between different backfilling of the pipe drains and sub-ballast layers in compliance with TNŽ 73 6949. Furthermore a verification of filtration function of different geotextiles including propositions of their suitable placement within construction of the pipe drain system is included.

Diploma thesis is bent on engineering design exhaust manifold for motor Formula SAE. Drive unit is here used atmospheric water-cooled gas- engine from motorcycle Yamaha YZF R6, 2005 model year. The design of the exhaust manifold is drawn to fulfil Formula SAE conditions.

This thesis deals with problems related to heating of hot service water. It focuses on solar water heating, describes individual types of solar panels and summarizes the existing information about solar water heating. It demonstrates actual problems of solar system solution on a specific example of a two-generation family house, where it analyses possibilities of diagnostics and control of such system. It also deals with suggestions of possible expansion of the current solar system.

Turbulent and cavitation induced pipe vibration is a large problem in industry often resulting in pipe failures. This thesis provides an experimental investigation on turbulent flow and cavitation induced pipe vibration caused by sharp edged baffle plates. Due to large pressure losses across a baffle plate, cavitation can result. Cavitation can be destructive to pipe flow in the form of induced pipe wall vibration and cavitation inception. Incipient and critical cavitation numbers are design points that are often used in designing baffle plate type geometries. This investigation presents how these design limits vary with the influencing parameters by exploring a range of different baffle plate geometries. The baffle plates explored contained varying hole sizes that ranged from 0.159 cm to 2.54 cm, with the total through area, or openness, of each baffle plate ranging between 11% and 60%. Plate thickness varied from 0.32–0.635 cm. Reynolds numbers ranged from 5 x 10^4 -85 x 104. The results show that the cavitation design limits are function of size scale effects and the loss coefficient only. The results also show that the loss coefficient for a baffle plate varies not only with total through area ratio, but also due with the plate thickness to baffle hole diameter ratio. Pipe wall vibrations were shown to decrease with increased through area ratio and increased thickness to diameter ratios. An investigation was also performed to characterize the attenuation of vibration in the streamwise direction of a baffle plate. It was show that the attenuation was largely effected by the presence of cavitation. Attenuation was shown to be a function of the geometry of the baffle plate. This work resulted in empirical models that can be used for predicting pipe vibration levels, the point of cavitation inception, and the streamwise distance where the attenuation of vibration levels caused by a baffle plate occurs.

Thesis (MEng) -- Stellenbosch University, 2014. / ENGLISH ABSTRACT: Solar energy is a time dependent, high-temperature radiant energy resource. The utility of a solar thermal energy system increases if the hot temperature source is available when it is needed most. This is realized by the thermal storage of the solar energy. Thermal storage gives greater versatility to a solar energy system by decoupling the heat source from the heat sink. A large quantity of energy may be stored during the melting process in a phase change material (PCM) within a small temperature range. This molten PCM can then deliver its absorbed heat at a constant temperature in a heating application. In this study a phase change storage system (PCS) is developed and proposed for a solar water heating application. This PCS system stores more heat per unit mass than would be possible with water across the same temperature range. The heat transfer rate in and out of many PCMs is slow because of the low thermal conductivity of the PCM. However, heat transfer enhancers (HTE), such as heat pipes and fins may be added to enhance heat absorption and heat removal rates. Heat pipes have the inherent capability to transfer heat at high rates across large distances, even where the temperature difference is small. In this thesis a description is given of a PCS system consisting of paraffin wax as the PCM and which uses rectangular heat pipes in conjunction with aluminium fins to enhance heat transfer. The storage design is modular and each module has the characteristic that enhanced heat transfer in and out of the PCM is possible when the module is heated or cooled. It also has the capability to quickly absorb or alternatively to supply heat at a nearly constant temperature during the phase change of the module. A rectangular module was designed and built. The module was then analysed under controlled heat absorption and heat removal cycles. The heat up experiment involved an electrical kettle as the hot temperature source. The heat sink was a mains water heat exchanger. The experimental results were compared to those of a transient numerical model, which calculates theoretically how the module will perform thermally under the given test conditions. The numerical model of the experimental set-up was validated when it was found that the numerical model results resemble the experimental results. The numerical model was then adapted to simulate a novel solar water heater (SWH) with an additional PCS container. The improvement over previous designs is that the additional storage container can be heated to a higher temperature than the allowable geyser temperature. The system also heats up and cools down at a faster rate than would be possible without the HTEs. From the numerical simulation the size and performance of such a system is determined. This numerical analysis indicated that a phase change storage system in a SWH application will increase the hot water delivered by a given solar collector and geyser by increasing the storage capacity and by heating up the geyser overnight for early morning hot water use. / AFRIKKANSE OPSOMMING: Son energie is ‘n tyd afhanklike, hoë temperatuur radiasie energiebron. Die bruikbaarheid van ‘n sontermiese energie sisteem verhoog indien die hoë temperatuur bron beskikbaar is wanneer dit die meeste benodig word. Dit kan verwesenlik word deur die sonenergie termies te stoor. Termiese storing bied groter veelsydigheid aan ‘n sontermiese stelsel deur effektief die hittebron te ontkoppel van die hitte sink. ‘n Groot hoeveelheid energie kan, gedurende die smeltingsproses in ‘n faseveranderingsmateriaal binne ‘n nou temperatuurband gestoor word. Hierdie gesmelte materiaal kan weer op sy beurt in die waterverhittingstoepassing, die geabsorbeerde hitte teen ‘n konstante temperatuur oordra. In hierdie studie word ‘n sonwaterverwarmer stelsel wat aangepas is deur ‘n addisionele latente hittestoor daaraan te heg, voorgestel. Hierdie faseverandering hittestoor kan meer hitte stoor as wat water in dieselfde temperatuur band sou kon. Die hitteoordrag tempo na en van baie van die faseveranderingsmateriale (FVM) is egter as gevolg van die lae termiese geleidingskoëfisient, stadig. Hierdie eienskap kan gelukkig verbeter word deur hittepype en hitteoordrag verhogings materiaal soos vinne by te voeg. Hittepype het die inherente eienskap om hitte teen ‘n hoë tempo oor groot afstande, oor te dra, selfs oor ‘n klein temperatuurverskil. In hierdie tesis word ‘n ondersoek rakende ‘n faseverandering storingsisteem wat bestaan uit paraffien was as die FVM en reghoekige hittepype wat te same met met aluminium finne gebruik word om die hitteoordragtempo te verhoog, beskryf. Die stoorontwerp is modulêr en elke module het die kenmerk van hoë hitteoordrag na en van die FVM. Die module het verder ook die eienskap om vining hitte te absorbeer of hitte af te gee. Dit gebeur teen ‘n konstante temperatuur gedurende die faseverandering van die FVM. Presies so ‘n reghoekige module is ontwerp en gebou en onder beheerde hitte absorbering- en hitte verwyderingsiklusse analiseer. Tydens die verhittings eksperiment is ‘n elektriese ketel van gebruik gemaak wat gedien het as die hoë temperatuur bron. Die hitte sink was ‘n hitteruiler wat kraanwater van ‘n konstante hoogte tenk ontvang het. Die resultate van die volledige toets is met die resultate van tydafhanklike numeriese model vergelyk. Hierdie numeriese model bereken teoreties wat die module se storing verrigting onder gegewe toets omstandighede sal wees. Die numeriese model se resultate het goed vergelyk met die resultate van die eksperimente. Die numeriese model van die module is toe aangepas om ‘n sonwaterverwarmer met addisionele stoortenk wat fase verandering materiaal gebruik, te simuleer. Hierdie ontwerp is anders as vorige ontwerpe in die sin dat hoër temperature as wat die warmwatertoestel kan hanteer, in die faseverandering storingstenk, bereik kan word. Die sisteem kan ook as gevolg van die hitteoordrag verhoging materiaal, vinniger verhit of afkoel en teen ‘n vinniger tempo. Die simulasie van die sonwaterverwarmer met FVM word gebruik om die grootte en verrigting van die sisteem te bepaal. Hierdie numeriese model toon aan dat wanneer ‘n addisionele faseverandering storingstelsel in ‘n sonwaterverwarmer toepassing gebruik word, die warm water wat die verbruiker uit die sisteem kan verkry, kan verhoog. Die rede hiervoor is dat meer hitte gestoor kan word, wat beskikbaar gemaak word aan die warm water tenk.

Dorsal-ventral (DV) polarity in the Drosophila embryo is defined by spatially regulated activation of the transmembrane receptor Toll, which is uniformly distributed throughout the early embryo's plasma membrane. Ventral activation of Toll is accomplished through the local production of its activating ligand, a processed C-terminal fragment of the Spätzle protein, which is generated in the last step of a proteolytic cascade involving the sequentially-acting proteases Gastrulation Defective (GD), Snake and Easter. Pipe protein, a homologue of vertebrate glycosaminoglycan modifying enzymes, which is expressed during oogenesis in ventral follicle cells adjacent to the developing oocyte, is believed to control the ventrally restricted processing of Spätzle. pipe expression and the sulfation of its enzymatic target in the ventral follicle cells leads to the formation of a stable ventral cue, embedded in the eggshell. Recently the Pipe enzymatic target has been identified as several protein components of the vitelline membrane, the inner layer of the eggshell. Prior to this work, an important piece of information missing from our understanding of Drosophila DV patterning was the identity of the initial step in the protease cascade that requires Pipe activity. Here, I show that the processing of Snake is independent of Pipe activity, while the processing of Easter requires Pipe function, indicating that Easter processing by Snake is the key proteolytic step that is controlled by Pipe activity and presumably the first cleavage event that is spatially regulated. A second key gap in our understanding of Drosophila embryonic DV patterning concerned the role of GD in the protease cascade. While GD is the protease that cleaves and activates Snake, the existence of two distinct classes of complementing gd alleles has suggested that GD provides another, distinct function. Investigations described here indicate that the second function of GD is to promote the ability of activated Snake to process Easter, independent of its Snake-processing function. Finally, I provide evidence for the formation of protein complexes containing various components of the serine protease cascade, which suggest that conformational changes in the complexes, which act to promote productive interactions between the proteins, are an important aspect of their activation. / text