Animal cells are often cultured in stirred tank reactors. Having no cell wall, these animal cells are very sensitive to the fluid mechanical stresses that result from agitation by the impeller and from the rising and bursting of bubbles, which are generated within the culture medium in the stirred tank to supply oxygen by mass transfer to the cells. If excessive, these fluid mechanical stresses can result in damage/death of animal cells. Stress due to the rising and bursting of bubbles can be avoided by using a gas-permeable membrane, in the form of a long coiled tube (with air passing through it) within the stirred tank, instead of air-bubbles to oxygenate the culture medium. Fluid mechanical stress due to impeller agitation can be controlled using appropriate impeller rotational speeds. The aim of this study was to lay the foundations for future work in which a correlation would be developed between cell damage/death and the fluid mechanical stresses that result from impeller agitation and bubbling. Such a correlation could be used to design stirred-tank reactors at any scale and to determine appropriate operating conditions that minimise cell damage/death due to fluid mechanical stresses. Firstly, a validated CFD model of a baffled tank stirred with a Rushton turbine was developed to allow fluid mechanical stresses due to impeller agitation to be estimated. In these simulations, special attention was paid to the turbulence energy dissipation rate, which has been closely linked to cell damage/death in the literature. Different turbulence models, including the k-ε, SST, SSG-RSM and the SAS-SST models, were investigated. All the turbulence models tested predicted the mean axial and tangential velocities reasonably well, but under-predicted the decay of mean radial velocity away from the impeller. The k-ε model predicted poorly the generation and dissipation of turbulence in the vicinity of the impeller. This contrasts with the SST model, which properly predicted the appearance of maxima in the turbulence kinetic energy and turbulence energy dissipation rate just off the impeller blades. Curvature correction improved the SST model by allowing a more accurate prediction of the magnitude and location of these maxima. However, neither the k-ε nor the SST models were able to properly capture the chaotic and three-dimensional nature of the trailing vortices that form downstream of the blades of the impeller. In this sense, the SAS-SST model produced more physical predictions. However,this model has some drawbacks for modelling stirred tanks, such as the large number of modelled revolutions required to obtain good statistical averaging for calculating turbulence quantities. Taking into consideration both accuracy and solution time, the SSG-RSM model was the least satisfactory model tested for predicting turbulent flow in a baffled stirred tank with a Rushton turbine. In the second part of the work, experiments to determine suitable oxygen transfer rates for culturing cells were carried out in a stirred tank oxygenated using either a sparger to bubble air through the culture medium or a gas-permeable membrane. Results showed that the oxygen transfer rates for both methods of oxygenation were always above the minimum oxygen requirements for culturing animal cells commonly produced in industry, although the oxygen transfer rate for air-bubbling was at-least 10 times higher compared with using a gas-permeable membrane. These results pave the way for future experiments, in which animal cells would be cultured in the stirred tank using bubbling and (separately) a gas-permeable membrane for oxygenation so that the effect of rising and bursting bubbles on cell damage/death rates can be quantified. The effect of impeller agitation on cell damage/death would be quantified by using the gas permeable membrane for oxygenation (to remove the detrimental effects of bubbling), and changing the impeller speed to observe the effect of agitation intensity. In the third and final part of this work, the turbulent flow in the stirred tank used in the oxygenation experiments was simulated using CFD. The SST turbulence model with curvature correction was used in these simulations, since it was found to be the most accurate model for predicting turbulence energy dissipation rate in a stirred tank. The predicted local maximum turbulence energy dissipation rate of 8.9x10¹ m2/s3 at a rotational speed of 900 rpm was found to be substantially less than the value of 1.98x10⁵ m2/s3 quoted in the literature as a critical value above which cell damage/death becomes significant. However, the critical value for the turbulence energy dissipation rate quoted in the literature was determined in a single-pass flow device, whereas animal cells in a stirred tank experience frequent exposure to high turbulence energy dissipation rates (in the vicinity of the impeller) due to circulation within the stirred tank and long culture times. Future cell-culturing experiments carried out in the stirred tank of this work would aim to determine a more appropriate critical value for the turbulence energy dissipation rate in a stirred tank, above which cell damage/death becomes a problem.

The dissertation investigates typical operation modes of the heat storage tank in the small-scale cogeneration (CHP) plant, analyses formation of thermal stratifi-cation in such storage tank and presents the simulation of the stratification. The main aim of the dissertation is to investigate peculiarities of operation modes of heat storage tank in small-scale CHP plant, develop an algorithm allowing to choose the storage tank volume and present a model allowing determination of thermal stratification in the storage tank at any time of its operation. / Disertacijoje nagrinėjami būdingi šilumos akumuliacinės talpos veikimo režimai, susiformuojantys nedidelės galios kogeneracinėje jėgainėje, tiriamas šiluminės stratifikacijos susidarymas tokioje talpoje ir atliekamas jos modeliavimas. Pagrindinis disertacijos tikslas – ištirti nedidelės galios kogeneracinės jėgainės šilumos akumuliacinės talpos veikimo režimų ypatumus, sudaryti algoritmą, padedantį parinkti tokios talpos tūrį ir pateikti modelį, leidžiantį nustatyti šiluminę stratifikaciją akumuliacinėje talpoje bet kuriuo jos veikimo metu.

In der vorliegenden Arbeit wird die Konzeptionierung und die Realisierung eines teilkontinuierlichen Thermolyseverfahrens zur rohstofflichen Verwertung von Polyethylen- und Polypropylenabfällen beschrieben. Die Ausführung in der zweistufigen Rührkesselkaskade gewährleistete dabei die Trennung der Prozessschritte Schmelzen sowie Cracken der Einsatzmaterialien, woraus ein Thermolyseöl hervorging, welches weitestgehend frei von den Verunreinigungen aus den Abfällen war. Das Thermolyseöl wies eine Zusammensetzung aus Benzin- und Dieselkomponenten auf und erfüllte einige entscheidende Kraftstoffkriterien. Zur Senkung der qualitätsmindernden Olefingehalte wurden in einem weiteren Teil dieser Arbeit Untersuchungen zur heterogen-katalysierten Hydrierung der Siedeschnitte im Schüttgutreaktor und im Rührautoklav durchgeführt. Dabei konnten die Olefingehalte durch den Einsatz eines Palladium-Platin-Trägerkatalysators sowie durch einen Nickel-Gerüstkatalysator maßgeblich gesenkt werden. Als unerwünschtes Nebenprodukt des Thermolyseprozesses resultierte ein geringer Anteil Koks, welcher in der Schmelze akkumulierte und sich teilweise an der Reaktorwand ablagerte. Die entstandenen Mengen wiesen eine Abhängigkeit von der Prozesstemperatur und -dauer auf und mussten aus dem Prozess geschleust werden. Als weitere Nebenprodukte traten ein leichtflüchtiges Spaltgas sowie ein Sumpfrückstand auf. Darüber hinaus wurde gezeigt, dass die aufzuwendende Energie für den Thermolyseprozess durch die Energiegehalte der Nebenprodukte gedeckt werden kann. Neben dem Einsatz als Kraftstoff empfahl sich das Thermolyseöl aufgrund seiner physikalischen und chemischen Eigenschaften gerade im Hinblick auf einen nachhaltigen Umgang mit Ressourcen als beachtenswerter Ersatz für fossiles Rohöl.

The objective of this project was to contribute to deepen the piece of knowledge about swi¬rling movement of the water in the hydraulic power plants’ water intakes, especially in case of the Swirl Turbine. The vortexes mostly occur near outflow holes in the bottom or walls of water tanks. Collectively they are called inflow vortices. According to the form they take they can be divided into four main categories. By the model research on hydraulic power plants’ inflow it is generally concerned on determination enough infallible conditions, under which the pulling-in of the air by a vortex into an inflow does not happen. For this purpose has been in the Fluid engineering laboratory projected and realized an experimental device enabling observation of creation, spread and extinction of the inflow vortices.

Approved for public release, distribution is unlimited / The U.S. Army uses a Unit Readiness Index to track the combat readiness of systems. The Unit Readiness Index relies on the accuracy of automated and manual testing of the hardware and related software of the Line Replaceable Units (LRUs) that comprise the system. These tests are based on a GO/NOGO scenario. When an LRU fails, vehicle commanders, and commanders up the chain of command, can override the failure and continue with a mission. Overriding the NOGO recommendations produces a false combat readiness status for the unit, and creates a number of problems related to unit combat decisions as well as logistical support. This thesis introduces a new process for more effectively tracking combat readiness. It outlines some of the problems associated with the current GO/NOGO scenario and examines the current tests, artifacts and data available from the current process. It proposes an additional Report process and shows how this new process will eliminate the readiness tracking problems associated with the GO/NOGO scenario. It also presents the design of a Vehicle Database and Master Fault Database to support the proposed process, and presents several sample reports generated from this Master Fault Database. / Civilian, United States Army RDECOM - TARDEC

En 1954, l’Arme Blindée et Cavalerie (ABC) est une arme qui monte en puissance pour faire face à la menace soviétique en Europe. Le général inspecteur de cette arme voit s’achever la guerre d’Indochine avec un soulagement car il pense pouvoir se consacrer pleinement à cette tâche. Aussi, est-ce avec une certaine réticence, qu’à partir de 1955, il fournit à la Xe région militaire (Algérie) les renforts qu’elle réclame. L’organisation opérationnelle des corps, l’instruction du personnel et le programme d’équipement s’en trouvent très perturbés. Voulant à la fois maintenir sa capacité opérationnelle en Europe et faire face aux besoins de l’Algérie, le commandement désorganise l’ABC. Les unités blindées ne sont adaptées ni à un conflit de type insurrectionnel, ni au terrain particulier de l’Algérie. Pourtant, à partir de 1958, elles donnent satisfaction. Leur composante portée s’est développée, leur puissance de feu et leur mobilité sont mises pleinement à profit sur les barrages, et les unités à cheval, qui ont refait leur apparition, sont employées plus judicieusement sur des terrains favorables. Mais cette adaptation s’est faite au prix de grands sacrifices. Le vieux matériel américain n’est remplacé que très progressivement soit par des engins français modernes (EBR ou AMX 13), que le commandement a le sentiment de gaspiller, soit par des nouveaux matériels (Ferret, AML 60, ou AMX 13 à tourelle de M24) qui ne peuvent être employés qu’en Algérie et dont l’acquisition se fait au détriment du char de 25 t dont doit pourtant être équipée l’ABC d’urgence. En somme, l’ABC aurait rencontré les pires difficultés si le conflit avait dû se prolonger au-delà de 1962. / In 1954, the French Armored Cavalry was a corps that was aiming to get stronger to face the Soviet threat in Europe. The Inspector General of this corps was relieved when the war in Indochina ended because he thought he could rededicate himself to this task. So it was with some reluctance, that from 1955 on wards, he provided the tenth military region (Algeria) with the reinforcements it required. The operational organization of the units, personnel training and equipment program found it very disturbing. Seeking both to maintain its operational capacity in Europe and meet the needs of Algeria, the command reorganized the Armored Cavalry. Armored units were not adapted neither to counter-insurgency, neither to the particular terrain in Algeria. Yet in 1958, they gave satisfying result. The vehicle-mounted infantry had been expanded, their firepower and mobility were expertly used over fences; and horseback units were re-created and deployed more wisely on a favorable terrain. But this re-organization cost very much. The old American equipment was only gradually replaced by French modern equipment (EBR or AMX 13), the command considering this equipment was being wasted. The new materials (Ferret, AML 60, or AMX 13 with M24 turret) could only in Algeria and their acquisition was at the expense the 25 ton tank. However, the French Armored Corps urgently needed this battle tank. To sum up, the Armored Cavalry would have encountered severe difficulties if the conflict had been extended beyond 1962.

Os transformadores de potência elétrica produzem um elevado nível de ruído que em alguns casos gera desconforto à comunidade vizinha. O presente trabalho desenvolve um modelo estrutural de elementos nitos que, com carregamento adequado, é capaz de reproduzir o deslocamento, medido durante a operação, de um transformador de potência elétrica. Este modelo estrutural é utilizado para calcular a redução do deslocamento das superfícies deste transformador decorrentes do emprego de absorvedores dinâmicos de vibração. Este modelo estrutural foi desenvolvido para estimar o número de absorvedores dinâmicos, sua massa e sua localização que permitiria reduzir o ruído acústico emitido por este transformador de potência até alcançar níveis de intensidade de som em comformidade com a legislação brasileira. / Electrical power transformers produce a high level of noise, which, in some cases, generate discomfort to the surrounding community. The present work develops a structural model by the Finite Element Method that, with adequate loading conditions, is capable of reproducing the displacement, measured during operation, of the transformer tank. The structural model has been used to compute the displacement reduction of the transformer surfaces by using dynamic vibration absorbers. The structural model was developed to estimate the number of dynamic absorbers, the mass and localization that could reduce the acoustic noise to levels of intensity of sound in accordance to the Brazilian law.

O objetivo principal deste trabalho foi caracterizar a estrutura da rede de armazenamento de álcool combustível brasileira destacando-se a infra-estrutura da região Centro-Sul no que diz respeito à capacidade estática e à localização dos tanques das unidades produtoras, distribuidoras e portos, além do cálculo e análise do índice de concentração dos principais agentes do setor nessa região. Para o estudo dos Índices de Concentração CR4 e do Índice de Herfindahl-Hirschiman HHI, utilizou-se a capacidade de armazenagem de álcool das unidades produtoras em nível estadual de detalhamento dos dados; a produção de álcool no ano-safra canavieiro de 2007/2008; a tancagem individual das unidades produtoras, dos terminais portuários e das bases distribuidoras. O levantamento realizado indicou que a maior concentração de usinas encontra-se na região Centro-Sul, com grande destaque para o estado de São Paulo que, além de possuir o maior número de unidade produtoras, também classifica-se como maior estado produtor e o que possui a maior tancagem. Nas colocações subseqüentes estão os estados de Minas Gerais e Paraná. Com capacidades de armazenagem menores ficam os estados de Goiás, Mato Grosso, Mato Grosso do Sul, Espírito Santo e Rio de Janeiro. O Índice de Concentração CR4 para a região Centro- Sul indicou que a maior concentração encontra-se entre as duas maiores empresas e que, à medida que mais empresas são adicionadas, a taxa de aumento do índice é menor, apontando para uma estrutura de mercado onde existem algumas empresas líderes, com grande participação na capacidade de armazenagem de álcool no setor sucroalcooleiro e um grande número de médias e pequenas empresas com menor participação no mercado. Especificamente no estado de São Paulo, o Índice de Concentração CR4 do setor equivale à metade de toda a capacidade de armazenagem de álcool do estado e tratam-se das mesmas empresas que compõem as quatro maiores de toda a região Centro-Sul. Em relação à rede armazenadora de álcool nos portos da região, o porto de Santos, no estado de São Paulo, obteve a maior concentração, seguido do Porto de Paranaguá no estado do Paraná. As bases distribuidoras de combustível que movimentam álcool combustível configuraram maior concentração no Estado de São Paulo, seguido do Paraná e Rio de Janeiro. / The main objective of this work was characterize the Brazilian ethanol storage chain, focusing on the centersouth infrastructure area, looking at the static capacity and the tanks localization of the unit production, distributor and ports besides, the calculation and the concentration degree of the main sector agents in this area. To study the four biggest group Concentration Index CR4 and the Herfindahl-Hirschiman index HHI, it was used the ethanol storage capacity per unit, in a state level of details; the ethanol production in the sugar cane season 2007/2008; the individual production of the unit storage, the ports and the distributor bases. The survey realized has shown that the biggest unit concentration is located inside the Center-South area, with main focus in São Paulo state, that has the biggest number of units, the biggest ethanol production and also the biggest storage. After that, its got Minas Gerais State and Paraná state. Goiás, Mato Grosso, Mato Grosso do Sul, Espírito Santo and Rio de Janeiro have the smallest capacities. The Concentration Index CR4 for the Center-South indicated that the biggest concentration is between two biggest enterprises, and, by the time that more enterprises are included, the index rate growth is smaller, pointing to market structure where it exists a small group of leaders companies with big participation in the ethanol storage capacity. In other hand, a big group of small and medium units have smaller market participation. Specifically in São Paulo state, the Concentration Index CR4 of the sector is equivalent to half of all ethanol storage capacity of this state and is about the same companies that are included in the four biggest units of the center-south area. Related to the ethanol storage chain at the ports, the Santos port, in São Paulo State, has the biggest concentration followed by Paranaguá port, in Paraná State. The fuel distribution bases that movement ethanol has bigger concentration in São Paulo State followed by Paraná State and Rio de Janeiro State.

O objetivo do presente estudo foi: a) comparar dois métodos de detecção e contagem de S. agalactiae, (cultura microbiológica e qPCR) em leite de vacas e de tanques; b) determinar a sensibilidade analítica e a repetibilidade do diagnóstico por qPCR em relação à cultura microbiológica para detecção de S. agalactiae em amostras compostas de leite de vaca e de tanque. Foram utilizadas amostras de leite de vaca (n=31) e de tanque (n=150), as quais foram submetidas à cultura microbiológica e contagem de S. agalactiae por cultura de microbiologia convencional e qPCR. Para avaliar a sensibilidade analítica, foi construída uma curva padrão com amostras de leite desnatado reconstituído estéril contaminado artificialmente com S. agalactiae (ATCC 13813). Em apenas duas amostras não foi possível amplificação de DNA, o que indica que a qPCR foi capaz de detectar S. agalactiae, em 96% e 97%, do leite de vaca e de tanque, respectivamente. Embora a técnica qPCR tenha apresentado alta sensibilidade analítica, não houve equivalência de resultados de contagem S. agalactiae entre os dois métodos propostos. Os coeficientes de variação interensaio utilizados para avaliar a técnica qPCR foram < 5%, o que demonstra que a técnica possui repetibilidade adequada. Portanto, não houve equivalência entre a contagem de S. agalactiae por cultura microbiológica padrão e a técnica de qPCR, provavelmente pela alta sensibilidade da técnica qPCR em quantificar DNA de células inviáveis. No entanto, a qPCR apresentou-se como uma técnica sensível para identificação de S. agalactiae em amostras de leite de vaca e de taque. / The aim of this study was to: a) to compare two methods of detection and enumeration of S. agalactiae (microbiological culture and qPCR) in cow`s milk and bulk tank milks, b) to determine the analytical sensitivity and repeatability of the diagnosis by qPCR in relation to microbiological culture for detection of S. agalactiae on composite samples of cow\'s milk and bulk tank milk. Samples of cow\'s milk (n = 31) and bulk tank milk (n = 150), which were submitted to microbiological culture and enumeration of S. agalactiae by conventional microbiology culture and qPCR. To evaluate the analytical sensitivity, a standard curve was made with samples of sterile reconstituted skim milk artificially contaminated with S. agalactiae (ATCC - 13813). In two samples was not possible the amplification of DNA, indicating that qPCR was able to detect S. agalactiae, 96% and 97% cow\'s milk and bulk tank milk, respectively. Although the technique has presented qPCR high analytical sensitivity, there was no equivalent result of counting S. agalactiae between the two proposed methods. The interassay coefficients of variation technique used to evaluate the qPCR were <5%, which demonstrate that the technique has adequate repeatability. So there was no equivalence between the counts of S. agalactiae by standard microbiological culture and qPCR technique, probably due to the high sensitivity of qPCR technique to quantify DNA of unviable cells. However, the qPCR presented as a sensitive technique for identifying S. agalactiae in samples of cow\'s milk and bulk tank milk.

O objetivo deste trabalho foi estudar a produção do antitumoral retamicina por células imobilizadas de Streptomyces olindensis ICB20 em biorreatores. A imobilização das células foi conseguida após uma etapa inicial de cultivo em erlenmeyers (reativação e pré-imobilização) e posterior envolvimento em gel, utilizando-se alginato de cálcio 3%; as esferas produzidas tinham diâmetro médio de 3,0 ± 0,2 mm. Foram utilizados neste trabalho os biorreatores tipo cesta (2,4 L de volume útil) e coluna de bolhas (1,6 L de volume útil), efetuando-se cultivos em batelada simples, bateladas repetidas e contínuos, visando-se uma comparação dos diferentes sistemas empregados. Também foram realizados alguns cultivos com células livres, a fim de efetuar uma comparação com os sistemas com células imobilizadas nos diferentes biorreatores. Os ensaios consistiram em empregar diferentes condições de agitação (300 e 500 rpm) e aeração (0,4 e 1 vvm) para o biorreator cesta em sistema com células imobilizadas, assim como diferentes vazões de aeração no biorreator coluna de bolhas (1, 2 e 3 vvm). Os cultivos em bateladas repetidas e contínuos foram operados a partir das melhores condições obtidas nos cultivos descontínuos. Foram aplicadas nos sistemas contínuos com células imobilizadas, as vazões específicas de alimentação de 0,05 e 0,2 h -1 no biorreator cesta e vazões de 0,015 a 0,05 h -1 no biorreator coluna de bolhas. A comparação entre os sistemas com células livres e imobilizadas mostrou que as limitações difusionais afetaram significativamente as cinéticas dos ensaios com células imobilizadas, considerando-se apenas uma batelada. A operação do biorreator cesta em sistema de bateladas repetidas apresentou os maiores valores de produção da retamicina (em torno de 1,5 a 1,7 UA), porém sua operação foi possível por apenas três bateladas. O sistema contínuo operado com vazão específica de alimentação de 0,03 h-1, com células imobilizadas no biorreator coluna de bolhas, mostrou ser o mais adequado dentre todos os ensaios realizados com células imobilizadas, apresentando estabilidade na produção, em torno de 0,8 UA, durante 96 horas de alimentação (cerca de três tempos de residência). / The purpose of this study was to investigate the production of the antitumor antibiotic retamycin by immobilized cells of Streptomyces. olindensis ICB20 in bioreactors. Cells were immobilized by entrapment in Ca-alginate gel (3%) after being grown in Erlenmeyers (reactivation and pre-immobilization cultures). The average diameter of the Ca-alginate beads was 3.0 ± 0.2 mm. Aiming to compare different cell systems, immobilized cell cultures were carried out in a 2.4L working volume basket-type stirred tank reactor (BSTR) and a 1.6 L working volume bubble column reactor (BCR) in batch, repeated-batch and continuous modes. Free cell suspension cultures were also performed and the results obtained compared to those in immobilized cell systems. Different agitation rates (300 and 500 rpm) and air flow rates (0.4 and 1.0 v.v.m.) were employed in the BSTR immobilized cell experiments.The BCR cultures were conducted at 1.0, 2.0 and 3.0 v.v.m. The optimal operating conditions for the batch mode were used in the repeated-batch and continuous cultures. Immobilized cells were grown in continuous mode at feed dilution rates of 0.05 and 0.2 h-1 in the BSTR and at 0.015 and 0.05 h-1 in the BCR. The comparative evaluation of the batch cultures with free and immobilized cells showed that diffusion limitations had affected the kinetics of cell growth and retamycin production in the immobilized cell systems. The highest average values of retamycin content (from 1.5 to 1.7 AU) were achieved in repeated batch cultures conducted in the basket-type reactor (BSTR) in spite of a limited number of batches (3 batches). Of all the systems, the continuous cell immobilized culture carried out in the BCR at a dilution rate of 0.03 h-1 proved to be the most adequate for retamycin production as retamycin levels remained stable (around 0.8 AU) over 96 hours (about 3 residence times).