Dissertations / Theses on the topic 'Tractor industry'

Tesis para optar al grado de Magíster en Administración
Autor no autoriza el acceso a texto completo de su tesis en el Portal de Tesis Electrónicas de la U. de Chile.
Mike Sutherlin, CEO of Joy Global Inc. (“JOY”), a global mining equipment manufacturer, was having lunch, in downtown Milwaukee, Wisconsin, with his wife, in November of 2010 when his cell phone began ringing. He hesitated answering, but recognizing the name, picked up to hear surprising news. It was a courtesy call from a friend at Caterpillar Inc. (“CAT”), the $85 Billion USD juggernaut, letting him know that CAT had just purchased JOY’s cross town rival, Bucyrus International, Inc. (“BI”), for $8.8B USD. JOY and BI were 2 Milwaukee, Wisconsin based mining equipment manufacturers who competed head to head on a worldwide stage. Evenly matched, with a market cap around $7B USD each, these two companies had spared in the surface and underground mining equipment market for heavy duty extraction mining equipment for over a hundred years since their founding in 1888 and 1889, respectively. All of a sudden, with this acquisition, what had always been a cross town rivalry would take on new proportions. CAT was the undisputed world wide heavy machinery giant with a market cap 10 times the size of JOY. Regarding the acquisition, Sutherlin comments, “Instead of a smaller competition across town all of a sudden this changed the world for us.” CAT brought to the table revenues which were 12 times larger than JOY, a global brand that stood for reliable heavy machinery, exceptional service through its army of worldwide distributors, and the ability to win deals by financing equipment through CAT financial. Sutherlin´s team had just put the finishing touches on their strategic plan for 2010. The exercise had reaffirmed some of JOY´s strategies, such as a continued commitment to focus solely in the mining equipment industry (versus including construction and farming equipment markets like CAT), a direct sales and service go to market model (versus third party distributors like CAT), and a focus on premium products with premium pricing (versus wining deals on price like BI). The plan also called for some changes such as moving beyond the dependence on a single product for their surface mining division and a move beyond coal specific products for its underground division. Would this strategy need to be revised? Would the plan withstand this new challenge? Sutherlin knew it was time to get his leadership team together, circle the wagons, and figure out, what, if anything, JOY could do to respond to this new competitive threat from CAT.

A depreciação de tratores agrícolas de rodas é um importante componente do custo fixo. A correta determinação desse parâmetro torna-se vital para o cálculo do custo da maquinaria ao longo da vida útil. Vários métodos são propostos para a estimativa da depreciação dos tratores com mais de um ano de uso: linear, saldo decrescente, soma do digíto dos anos, fundo de recuperação de capital e os valores publicados pelo jornal “O Estado de São Paulo”. O mais adequado entre os métodos disponíveis é o preço de mercado, que está baseado na pesquisa do valor da maquinaria junto ao mercado. Este trabalho consiste, em uma pesquisa para o levantamento, no mercado, de preços de venda de tratores agrícolas de rodas usados e na comparação dos valores obtidos (valor real de mercado) com os propostos na bibliografia. Para obtenção dos preços de mercado foi elaborado um questionário contendo as informações sobre o exemplar avaliado e os principais componentes de um trator agrícola, a fim de avaliar o estado de conservação do trator, indicando notas de 1 (ruim) a 5 (ótimo), conforme o estado dos componentes . O questionário foi disponibilizado no site da Escola Superior de Agricultura “Luiz de Queiroz” ESALQ-USP, tendo sido enviado a concessionários de todo país um pedido para que participassem da pesquisa. O baixo índice de respostas, cerca de 3%, motivou uma pesquisa feita junto a concessionários num raio de 150 km da cidade de Piracicaba. A etapa posterior à coleta foi a análise da vida útil (em anos), potência, horas trabalhada e o estado de conservação dos tratores avaliados. Com o avanço da idade do trator o estado de conservação ia se deteriorando, tendo sido encontrados tratores com até 34 anos de vida útil. A análise das horas trabalhadas foi prejudicada pela falta de confiabilidade nos horímetros e nas informações coletadas em tratores com instrumentos danificados. Potências encontradas na frota avaliada foram concentradas nas com maior índice de comercialização no país. A análise de regressão foi significativa somente em relação à vida útil e preço de mercado. A comparação entre o modelo obtido e os métodos propostos revelou uma diferença expressiva no primeiro ano, sendo que o modelo empírico demonstrou-se preciso: a partir do sétimo ano, em comparação com o método linear e o saldo decrescente; a partir do terceiro ano, em relação á soma dos dígitos dos anos e os valores publicados em “O Estado de São Paulo”; e a partir do oitavo ano, em comparação com o método fundo de recuperação de capital.
The depreciation of wheeled tractors is an important component of the fixed cost. The right determination of this parameter is vital to determine the machinery cost during its useful life. Several methods are proposed in order to estimate tractor depreciation with more than a year of use: linear, decreasing balance, sum of the year’s digit, fund of capital recovery and the values published by the newspaper “O Estado de São Paulo”. The most adequate among the available methods is the market price, which is based on research of the machinery value ok tractor dealers. This work consists in a surveying of sale prices of agricultural wheeled tractors and in the comparison of the obtained data (value practiced in the market) with those obtained by methods proposed on references. In order to obtain these data it was elaborated a questionnaire, which had fields for the evaluated machine and its main components to be evaluated. For the evaluation of the tractor conservation, grades from 1 (bad) to 5 (excellent) were attributed to each component. This questionnaire was available on the web site of the College of Agriculture “Luiz de Queiroz”, University of São Paulo. Tractor dealers throughout the country were contacted and asked to join the survey. The low rate of answers (3%) motivated a survey done directly to dealers located in a 150- km radius from Piracicaba, state of São Paulo. The step after the data collection was the analyses of useful life (years), power, worked hours and the conservation state of the evaluated tractors. As the tractor age was increasing the conservation state was worsening. Tractors up to 34 years of use were counted. The analysis of worked hours was hardened by the lack of trustfulness of the hour counter and by the information gotten in tractors with broken instruments. Power levels found in the evaluated fleet were concentrated on those more traded in Brazil. The regression analysis was significant only when useful life and market price were related. The comparison between the developed model and the proposed methods revealed the biggest difference on the first year of use, and it became more trustful from the seventh year of use, comparing with the linear and decreasing balance methods; when comparing to the sum of the year’s digit method and the values published by the newspaper “O Estado de São Paulo”, from the third year of use, and finally, when comparing to fund of capital recovery method, from the eighth year of use.

x, 103 h. : il. ; 30 cm
El planeamiento estratégico de Omega Tractor´s desarrollado en el presente documento se realizó identificando las estrategias que la compañía debe implementar para generar un posicionamiento estratégico que le permita aprovechar las condiciones del mercado en su sector y desarrollar sus potencialidades, todo enmarcado en una visión, misión, valores y código de ética. Este planeamiento sigue la metodología del modelo secuencial del proceso estratégico. Omega Tractor’s es un compañía dedicada al rubro de comercialización de repuestos, prestación de servicios de reparación y alquiler de maquinaria pesada, con operaciones en la región sur del Perú, este sector en los 5 años previos al año 2014 se mostró muy dinámico por la gran presencia de operaciones mineras e inversión en obras civiles de infraestructura vial, lo que permite a la compañía desarrollar una propuesta comercial más agresiva y superar deficiencias internas enfocada principalmente en el desarrollo de una cultura organizacional de excelencia
Strategic planning of Omega Tractor 's developed in this paper was performed by identifying the strategies that the company should implement to generate a strategic position that allows to take advantage of market conditions in the sector and develop their potential , all framed in a vision, mission, values and ethics . This planning methodology follows the sequential model of the strategic process. Omega Tractor 's is a company dedicated to the commercialization of spare parts , service repair and rental of heavy equipment with operations in the southern region of Peru , this sector in the 5 years prior to 2014 was very dynamic due the large presence of mining operations and investment in civil works road infrastructure , enabling the company to develop a more aggressive commercial proposal and overcome internal weaknesses focused primarily on the development of an organizational culture of excellence
Tesis

O petróleo, por ser uma das principais fontes primárias de energia e também matéria prima para uma série de produtos, é hoje um dos recursos naturais não renováveis mais importantes do mundo. O petróleo encontra-se acumulado no subsolo, e foi produzido pela ação da natureza, a partir dos restos de animais e vegetais, num processo que levou milhões de anos para ser concluído. Inicialmente, é possível extrair apenas uma parte do petróleo contido em um reservatório (cerca de 25%), e por este motivo injeta-se água na jazida para aumentar a recuperação do restante deste insumo. Com o intuito de otimizar este processo, denominado Recuperação secundária, traçadores são utilizados para obtenção de informações acerca do fluxo de água dentro do reservatório. Para que um determinado composto possa ser aplicado como traçador, ele deve cumprir uma série de requisitos, dependendo da investigação que se deseja efetuar. No caso de traçadores para estudo do comportamento da água injetada no reservatório, um dos principais requisitos é que ele não se atrase com relação às moléculas de água, ou seja, que ele não fique retido nas superfícies rochosas (fenômeno denominado sorção) nem se particione com a fase orgânica. Existem modelos matemáticos distintos para representar os processos de sorção, sendo que o mais usado estabelece uma relação linear entre a concentração do composto sorvido pela rocha e a concentração remanescente em solução uma vez atingido o equilíbrio, expressa pelo coeficiente Kd. Este coeficiente pode ser estimado de maneiras diferentes, mas os métodos mais usados são por batelada e por deslocamento em meio poroso, sendo que o último leva em consideração efeitos hidrodinâmicos. No presente trabalho foi montado um sistema experimental automatizado para realização de testes desta natureza, onde as válvulas motorizadas e o software para controle remoto e aquisição de dados foram desenvolvidos. As amostras rochosas empregadas nos testes foram arenitos provenientes da Formação Botucatu, similar às rochas constituintes da maioria dos reservatórios de petróleo. O estudo da dinâmica deste sistema foi conduzido usando o NaCl como traçador de referência, uma vez confirmado que seu comportamento é igual ao da água tritiada (considerada o traçador ideal para fases aquosas). A determinação quantitativa deste composto nos efluentes foi realizada por condutimetria direta, por meio de uma célula para medidas em fluxo posicionada horizontalmente, visto que na vertical ela provoca mudanças no comportamento hidrodinâmico do analito. Também foi confirmado que a concentração da solução de NaCl injetada influencia no perfil das curvas de resposta obtidas em testes de deslocamento em coluna, sugerindo que em concentrações mais baixas as espécies iônicas Na+ e Cl- sofrem retardo em relação ao fluxo de água. Além disso, a vazão de operação da bomba deve ser mantida constante em um valor menor que 5 mL/min, pois para valores maiores a balança demonstrou encontrar dificuldade para estabilizar as medidas, comprometendo o envio de seus dados para o computador. Por fim, a comparação entre os resultados obtidos em um teste controlado manualmente e em outro automatizado evidenciou uma pequena diferença entre ambos, causada pelas formas distintas de se calcular o volume injetado em cada um dos testes. Entretanto, apesar das pequenas limitações e discrepâncias apresentadas, a montagem e posterior automatização do sistema para teste de deslocamento em meio poroso foi bem sucedido.
Petroleum, nowadays, is one of the most important natural resources in the world, since it is one of the main primary sources of energy and also raw material for many different products. It can be found accumulated in the subsoil, and was produced from the remaining portions of animals and vegetables, in a process that took millions of years to be concluded. Initially, only a small fraction of the oil contained in a reservoir (about 25% or less) can be extracted (phenomenon named sorption) or partitioned within the organic phase. Distinct mathematical models may represent the sorption without external help, and for this reason water is injected in the reservoir to increase the recovery of the remaining quantity. Aiming at optimizing this process, called Secondary Recovery, tracers are used to provide information concerning the water flow inside the reservoir. In order to be used as a tracer, a given compound must fulfill a series of requirements, depending on the desired purpose. Tracers applied to study the water behavior inside the reservoir, must follow water molecules without being retarded in the rocky surfaces processes, and the most used model establishes a linear relation between the sorbed amount of the compound and its remaining concentration in solution at equilibrium, expressed by the distribution coefficient, Kd. This coefficient can be estimated in different ways, laboratory methods such as stirring and flow-through being the most used. The latter has the advantage of incorporating hydrodynamic effects in its results. In the present work an automatized experimental system for carrying out tests of this nature has been constructed. Motor driven valves and a software for implementing remote control and acquisition of data have been developed. Sandstone samples from Botucatu Formations similar to reservoir rocks are widespreadly distributedand were used in these tests. The dynamics of this system was also investigated using NaCl as reference tracer, since its behavior is in quite good agreement with tha of tritiated water (considered the ideal tracer for water phases). Its concentration in the effluent was determined online by condutimetry, using a flow-through cell at horizontal position, since it changes the hydrodynamic behavior of the compound when vertically positioned. It was also confirmed that the NaCl concentration in the injected solution influences the profies of the tracer breakthrough curves obtained in flow-through experiments, suggesting that the transport of the ionic species Na+ and Cl- is slower than that of water. Moreover, the pump flowrate, which is is controlled by a balance connected to a computer, should be less than 5 mL/min. At higher values the balance will not be able to get stabilized upon fluctuations, thus compromising the transmission of signals to the computer. Finally, breakthrough curves from automatizated and manually controled experiments were compared, and a small difference between both could be observed, caused by the different way of calculating the injected volume in each test. In spite of these small limitations and discrepancies, the construction and automatization of the system for flow-through tests were successful.

Les eclissages constituent l'un des elements les plus importants de la structure aeronautique. Les eclissages sont des assemblages boulonnes ou rivetes de pieces planes ou quasi-planes chargees dans le plan. Le but de ces travaux de these est d'ameliorer la conception de ces assemblages pour eviter des fissurations prematurees de fatigue. Nous avons montre par la technique des plans d'experiences, la meilleure disposition des boulons pour homogeneiser le transfert de charge aux lignes de fixations. La simulation numerique de differents types d'eclissage a montre l'existence d'un angle optimal de dessin des eclisses qui rend les fixations de la ligne extreme isocritiques. Une courbe donnant la valeur de cet angle en fonction du rapport de contrainte (traction/flexion) est proposee. Les resultats theoriques ont ete valides par des essais statiques et de fatigue sur une machine concue et realisee a cet effet. Une bonne correlation a ete obtenue entre les resultats des simulations numeriques et les essais statiques. Les essais de fatigue ont montre que la nouvelle disposition constructive a une endurance deux fois plus elevee que l'ancienne. Les recommandations qui ont ete faites pour la conception des eclissages de cadres d'avions civils devraient permettent d'ameliorer la performance de ces structures. Les resultats obtenus seront integres au manuel de conception de l'aerospatiale.

In dieser Arbeit wird ein industriell genutzter Metallreiniger auf Basis nichtionischer Tenside untersucht. Dabei werden ausschließlich Messmethoden verwendet, die sich auch für eine industrielle Fertigung eignen. Zu Anfang enthält die Arbeit kurze Abrisse zum gegenwärtigen Kenntnisstand bezüglich der Inhaltstoffe industriell genutzten Reiniger, der Analytik von Tensiden in Reinigern und der Adsorption der Tenside auf Feststoffoberflächen. Im Mittelpunkt der Arbeit steht neben der Charakterisierung und Analyse des Reinigers die quantitative Bestimmung der im Reiniger enthaltenen Tenside in industriellen Reinigungsbädern. Mit Hilfe der Hochleistungsflüssigkeitschromatografie mit einem Verdampfungs - Lichtstreudetektor wird die quantitative Verteilung der Tenside in Reinigungsbädern unter verschiedenen der industriellen Fertigung entsprechenden Bedingungen untersucht. Die Adsorption der im Reiniger enthaltenen Tenside auf der Metalloberfläche unter Fertigungsbedingungen wird mit Fluoreszenzspektroskopie und IR-Spektroskopie quantitativ bestimmt. Im letzten Kapitel wird auf die Umsetzung der gefundenen Ergebnisse in die industrielle Praxis eingegangen.

Um campo interessante para aplicação de técnicas nucleares devido à complexidade dos problemas a serem estudados e importante devido ao forte impacto econômico e estratégico é a industria de petróleo. Pelas técnicas nucleares podem ser obtidas informações preciosas. A utilização de traçadores auxilia a caracterização de um reservatório de petróleo e permite que se tomem posteriormente decisões importantes para o processo de recuperação deste recurso natural. O estudo é feito em uma malha envolvendo poços injetores e produtores, mas com um único traçador não é possível discriminar a contribuição de diferentes injetores para um determinado produtor. Devido a necessidade de se ter vários traçadores para serem usados na recuperação de poços de petróleo é proposto o desenvolvimento de traçadores ativáveis. Foram escolhidos para serem usados como traçadores elementos do grupo dos terras raras lantânio (La) e európio (Eu) por apresentarem elevada seção de choque e facilidade de obtenção. Estes elementos foram complexados com quelantes orgânicos para diminuir o grau de perdas ou retardo do traçador em relação à fase aquosa. Esses quelantes são os ácidos aminopolicarboxílicos EDTA, DTPA e DOTA. Para verificar se ocorreu a complexação foi feita análise por espectrometria no infravermelho. Com o resultado observou-se que houve a complexação em todos as amostras. Para separar interferentes como sódio, cloro e bromo presentes na água de produção foi utilizado um processo de coprecipitação. O processo foi eficiente já que conseguiu precipitar os terras raras separando-os do sódio e bromo presentes na água. Para verificar a partição do traçador com a fase oleosa e a fase aquosa foi realizado o teste de partição e em seguida calculado o coeficiente de partição ( Kao ) para todos os complexos (traçadores) em todos os testes. Foi realizado um teste em corpo de prova para determinar os parâmetros de interação do traçador candidato com a rocha. Foram utilizados como traçador o trítio, La-EDTA e cloreto de európio. No caso do trítio, que serviu como referência para avaliação dos demais traçadores, não ocorreu retenção do traçador no interior dos poros do corpo de prova. Para o cloreto de európio e La-EDTA observou-se a ocorrência de adsorção nas superfícies internas dos poros do corpo de prova, seguida de dessorção.
The application of nuclear techniques to the oil industry has both scientific and economical interest due to the complexity of the questions that have to be answered and to the strong economic and strategic impact of the fuel production activity. Valuable information can be obtained employing nuclear methods. In particular, they are instrumental in describing detailed flow patterns and other features of oil reservoirs that are unattainable to other methods. Besides, the information they provide substantiate more sound decisions on actions related to the recovery of this important natural resource. Tracer studies in oil fields are performed in a net of injection and producing wells. Thus, the use of only one tracer species would not discriminate the contributions of distinct injector wells to the response of a given production well. Hence, a multi-tracer experiment is required, and in to meet this purpose the use of activable tracers is proposed. As additional tracers lanthanum (La) and europium (Eu) were chosen from the rare earth series due to their large neutron cross sections and availability. In order to decrease losses to the oil phase and retardation of the tracer relatively to the aqueous phase, these elements were complexed with organic chelating ligands: the polyamino-carboxylic acids EDTA, DTPA , and DOTA. Infrared spectrometry was used to check complexation. Its results showed that complexation occurred in all the samples. A coprecipitation process was used to eliminate interfering agents such as sodium, chlorine, and bromine present in the water. The procedure proved to be efficient since it succeeded in precipitating the rare earths, thus separating them from the sodium and bromine dissolved in the water. In order to check the partition of the tracer between the aqueous and organic phases, tests were carried stirring the two phases together and measuring the tracer concentrations in the aqueous phase; the partition coefficient was ( Kao ) then calculated for all the combinations of the two lanthanides and three ligands. Continuous tests pumping the tracer through reservoir rock samples were also carried. Tritiated water was used as a reference tracer and the lanthanides employed were in form of La- EDTA and EuCl3. The last two were somewhat retarded due to adsorption followed by desorption in either the rock or oil phases

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A Resolução CONAMA N 430/2011 exige a utilização de dois bioensaios (dois níveis tróficos) para avaliação ecotoxicológica de efluentes, mas a seleção ao acaso de bioensaios pode permitir lançamentos tóxicos. A sensibilidade dos bioindicadores irá depender da substância tóxica avaliada. Assim, baterias de bioensaios sensíveis devem ser estabelecidas às classes de contaminantes. Na literatura não há estudos que indiquem uma bateria de bioensaios ecotoxicológicos sensíveis para avaliação de efluentes contendo principalmente metais. Esse trabalho teve como objetivo selecionar uma bateria de bioensaios ecotoxicológicos que conjuntamente detectem toxicidade ao maior número de metais isolados e em misturas e que sejam realizados no menor tempo indicado pelas normas de padronização. Foram avaliadas as sensibilidades de seis bioensaios, incluindo três níveis tróficos (produtores, algas: Pseudokirchneriella subcapitata e Chlorella vulgaris; consumidores primários, cladóceros: Daphnia similis e Ceriodaphnia dubia; consumidores secundários, peixes: Poecilia reticulata e Danio rerio), a 10 espécies metálicas individuais (Ag+, Cd2+, Cu+, Cu2+, Cr3+, Cr6+, Pb2+, Ni2+, Zn2+ e Hg2+) e a efluentes reais (siderúrgicos) e simulados em laboratoriais (baseado nos limites máximos permitidos para descarte). Os bioensaios com peixes foram os menos sensíveis, D. rerio não detectou toxicidade em nenhum dos efluentes testados. P. subcapitata foi um bom bioindicador de toxicidade de Cr3+ e D. similis foi o organismo mais sensível a Hg2+. O uso combinado do bioensaio crônico de 72h com C. vulgaris e do bioensaio agudo de 48h com C. dubia garantiu a detecção das menores concentrações dos metais tanto individualmente quanto em efluentes reais e simulados. Apesar de P. subcapitata ser um bom bioindicador da toxicidade de Cr3+, a interação dos metais em misturas tornou C. vulgaris igualmente sensível. Da mesma forma, apesar de D. similis ter sido mais sensível ao Hg2+, o efeito da toxicidade dos efluentes com maiores teores de Hg2+ foi detectado por C. dubia
CONAMA Resolution No. 430/2011 requires the use of at least two bioassays (two trophic levels) for ecotoxicological evaluation of effluents. The use of bioassay batteries is necessary to evaluate toxic effects at various biological levels. The selection of bioassays without prior testing and determination of the most sensitive/suitable groups for each impact may allow the discharge of effluents that pose a threat to the environment. In the present study we tested and selected a battery of sensitive ecotoxicological bioassays for detecting toxic effects of metals. The sensitivities of six organisms were evaluated (algae Pseudokirchneriella supcapitata and Chlorella vulgaris, Cladocera Daphnia similis and Ceriodaphnia dubia, and fish Poecilia reticulata and Danio rerio) after exposure to 10 individual metal species deemed toxic to the aquatic environment (Ag+, Cd2+, Cu+, Cu2+, Cr3+, Cr6+, Pb2+, Ni2+, Zn2+, and Hg2+) and to real (steel-mill) and laboratory simulated effluents (based on maximum allowable cocentration of metal in effluent for disposal). In the bioassays, fish were the least sensitive; D. rerio showed no sensitivity to any of the effluents tested. P. subcapitata was a good bioindicator of Cr3+ toxicity, and D. similis was the most sensitive organism to Hg2+; but the toxic effect of effluents with higher levels of Hg2+ was better detected by C. dubia. Although P. subcapitata be a good bioindicator of toxicity of Cr3+, the interaction of metals in mixtures became equally sensitive C. vulgaris. The most sensitive battery of bioassays to detect low concentrations of dissolved metals in effluents was the 72-h chronic test with C. vulgaris and the 48-h acute test with C. dubia. The identification of these responses is important for countries that are starting to ecotoxicological assessment of their effluents, as well as Brazil, and serves as a reference for the environmental agencies in the management and control of effluents. The limits of acceptability of toxicity should be based on batteries of tests with sensitive organisms

Etude par microscopie electronique en transmission et par diffraction de rayons x de l'evolution structurale au cours de revenu allant de 300 a 525c. Ces etudes montrent que la morphologie et la distribution de la phase alpha peuvent etre controlees par traitement thermique. Etude de l'influence des parametres: double mise en solution, double revenu, vitesse de montee en temperature sur les proprietes de traction et de tenacite. Comparaison entre les deux alliages

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Traçadores são utilizados na explotação de reservatórios de petróleo para fornecer informações que auxiliam na otimização das operações envolvidas. Esta utilização já é comumente praticada fora do Brasil, sendo os mais empregados os radioativos, que apresentam sobre os compostos químicos as vantagens da simplicidade e sensibilidade de detecção e do custo. Uma possibilidade interessante é representada pelos traçadores ativáveis, que podem ser introduzidos no sistema a estudar no estado inativo e serem posteriormente amostrados e dosados por Ativação Neutrônica. Para esta aplicação os elementos da série dos lantanídeos foram testados, visto que estes oferecem características nucleares adequadas para análise. Os traçadores eficientes serão aqueles que não se atrasem ou se percam por interação com as rochas e/ou fluidos não aquosos presentes no reservatório, ou seja, que possuam elevada solubilidade em fase aquosa, coeficientes de partição nulos com a fase orgânica e que não sejam adsorvidos nas elevadas superfícies específicas disponíveis nas formações microporosas das quais desalojam as gotículas de petróleo. Deste modo foi necessário a complexação e quantificação do rendimento através da técnica de Cromatografia Líquida de Alta Eficiência (CLAE). As técnicas espectrométricas de Ressonância Magnética Nuclear (1H e 13C) e Infravermelho (IV) também foram empregadas para caracterização das espécies formadas. Foram realizados testes com o lantânio (La), o európio (Eu) e o disprósio (Dy) com os ligantes ácidos aminopolicarboxílicos (EDTA-2, DTPA) e tia-dicarboxílicos (C4H6SO4 , C7H12S2O4). Após a quantificação do rendimento e caracterização dos complexos de lantanídeos, concluiu-se que há complexação das espécies ligantes com os lantanídeos estudados. Os complexos obtidos em maior rendimento foram então submetidos a testes que simulam uma possível partição destes com a fase orgânica (Kp) e/ou sólida (Kd) do aqüífero, pela metodologia da Análise por Injeção em Fluxo (Flow Injection Analysis FIA) e por testes em um corpo de prova que simula as condições de fluxo em um reservatório de petróleo. O cálculo da partição determinada por Ativação Neutrônica e Espectrometria de Emissão Atômica com Plasma Indutivamente Acoplado (ICP/AES) apresentou um resultado nulo, o que torna possível a utilização dos respectivos complexos como traçadores ambientais em campo de petróleo. Os testes em corpo de prova evidenciaram uma excelente concordância entre o comportamento dos lantanídeos complexados e do traçador de referência (água tritiada). Um outro teste com a metaloporfirina (MnP) foi realizado como estágio prévio para o desenvolvimento de um novo traçador e os resultados positivos indicaram a viabilidade de sua futura utilização. Foram realizados os mesmos testes que para os complexos de lantanídeos, sendo que as determinações dos coeficientes de partição tanto com a fase orgânica (Kp) como com a fase sólida (Kd) foram efetuadas através da Espectrometria UV-Vis.
Tracers are used in the explotation of petroleum reservoirs in order to obtain information that help to optimize its operations. They are presently used on a routine basis in many countries, and the more often applied are the radiotracers, due to some advantages they have over the chemical tracers, such as the simplicity and the sensitivity of their detection besides the cost factor. One of the most conspicuous applications of tracers to reservoirs production activities refers to the evaluation of the secondary recovery techniques, due to their capability to inform about what happens in between the injection and production wells, differently from the other techniques that provide information only at discrete points. An option of interest for the normally required multiple tracer tests is afforded by activable tracers that can be fed to the system under study in the inactive state and have their samples collected at the exit irradiated and measured by Neutron Activation Analysis. Some of the elements of the lanthanide series that exhibit very high thermal neutron cross sections have been tested for this purpose. A properly performing tracer should not lag behind the liquid flow nor be lost through interactions with the rocks and non aqueous fluids inside the reservoir. This means that they must be quite hydrophilic, and have nearly null partition coefficients so that they are neither adsorbed on the internal surfaces of the rock pores nor migrate to the oil phase. Hence it has been necessary to form complexes of the lanthanide metals with appropriate ligands. Besides, to certify the product and to measure the achieved yield, these complexes had to be analyzed by High Performance Liquid Chromatography (HPLC), by 1H and 13C Nuclear Magnetic Resonance (NMR), and by Infrared Spectrometry (IR). The analyses have confirmed the complexation of the lanthanides processed by a previously selected methodology. Following that the performance of these lanthanide complexes as tracers have been tested in essays that simulate the possibility their partition in the oil phase (Kp) as well as their adsorption (Kd) in the solids inside the reservoir, by means of the Flow Injection Analysis (FIA) technique and of core tests, respectively. Tests have carried with lanthanum, europium and dysprosium, that have been complexed with aminopolicarboxylic acids (EDTA2-, DTPA), and with tiacarboxylic acids (C4H6SO4, C7H12S2O4). The measurement of partition, that has been carried by both Instrumental Neutron Activation Analysis (INAA) and Internal Couple Plasma/Atomic Emission Spectrometry (ICP/AES), evidenced null partition and this qualifies these complexes as oil field tracers. The core tests also displayed an excellent match between the lanthanide complexeds and the reference tracer used (tritiated water). On e other test using metal-porphyrin (MnP) has been performed as a previous stage for the development of a novel tracer and the positive results obtained have shown its feasibility for future applications. This complex has been submitted to the same tests performed with the lanthanides and the measurement of both the water phase and the oil, phase partition coefficients (Kp and Kd, respectively) has been carried using UV-Vis spectrometry.

L'utilisation des matériaux composites en proportion grandissante dans les structures des avions de nouvelle génération oblige, pour des questions de sécurité et de coûts, les constructeurs à établir des règles de dimensionnement prenant en compte les spécificités du comportement physique en général, mécanique en particulier, du comportement des structures composites. Ce projet concerne la tolérance aux dommages sur assemblages boulonnés des plaques à fibres de carbone Module Intermédiaire/matrice époxy T800/M21. Dans un premier temps, le comportement mécanique de ces liaisons boulonnées a été étudié grâce à des essais de traction sur éprouvettes représentatives de plaques aéronautiques assemblées en simple recouvrement. La seconde partie de l'étude a consisté à impacter des assemblages en simple recouvrement proche d'une ligne de fixation, de comprendre et de modéliser la tenue résiduelle en traction après impact. La dernière partie décrit l'effet d'impact à basse vitesse sur le comportement des éprouvettes en tension initiale (pour simuler le comportement en fonctionnement de l'assemblage) en utilisant un montage spécifique, pour comparer l'effet des impacts avec et sans tension initiale sur la tenue résiduelle de l'assemblage. Enfin, une modélisation numérique par éléments finis introduisant l'endommagement et la rupture à l'échelle du pli, a permis de réaliser des comparaisons essais-calculs sur un assemblage et une stratification. Le modèle permet de retranscrire les phases d'endommagement rupture relevées expérimentalement. Il constitue une base pour une suite du développement futur des modèles
The proportion of use of composites materials in the structures of the new generation airplane is growing, for the questions of safety and costs, the manufacturers have established rules of sizing taking into account generally the specificities of the physical behavior, mechanics in particular, behavior of the composite structures. This project concerns the tolerance in damage on assemblies screwed by plates with intermediate modulus fiber carbon / epoxy matrix T800 / M21. As a first time, the mechanical behavior of bolted junctions was studied thanks to essays of traction on representative specimens of aeronautical plates assembled in single lap shear (SLS) joint. The second part of the study is consisted to impact on the assemblies in single lap close to a fastening line, understanding and modeling the residual tensile strength after impact.The last part describes the effect of low speed impact on the specimens behavior which have been submitted to initial tension (to simulate the behavior in operation of the assembly) using a specific test, to compare the effect of the impacts with and without initial tension on the residual behavior of the composite bolted joint. Finally, a numerical finite element model with a ply damage and failure behaviors, made it possible to make comparisons between tests and numerical computations for a specific lay-up. The model shows the different phases of damages and failures observed experimentally. It provides a good basis for further development of these numerical models

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Dentre as diversas aplicações dos radioisótopos, a utilização dos radiotraçadores é considerada uma das mais importantes, no diagnóstico de funcionamento dos equipamentos de processos, em plantas de indústrias químicas e petroquímicas. Os radiotraçadores são utilizados em procedimentos analíticos para obtenção de dados qualitativos e quantitativos de sistemas, em estudos de transferências físicas e físico-químicas. Na produção de radioisótopos gasosos utilizados como traçadores em processos industriais, destacam-se o 41Ar e 79Kr, gases nobres (inertes) que possuem baixa reatividade com os demais elementos químicos. O 41Ar é um emissor gama de alta energia (1,29 MeV) e apresenta elevada porcentagem de transformações com essa energia, o que resulta em quantidades relativamente pequenas necessárias em relação a outras para uma detecção eficaz, mesmo em componentes com grandes espessuras. Atualmente, a produção de radioisótopos gasosos em reatores nucleares de pesquisa é realizada em pequenas quantidades (bateladas), por meio de ampolas de quartzo contendo o gás natural 40Ar ou 78Kr. Nesse sentido, o objetivo desse estudo é desenvolver um sistema de irradiação capaz de produzir em escala contínua, o radioisótopo gasoso 41Ar, dentre outros, com atividade de 7,4x1011 Bq (20 Ci) por ciclo de irradiação, por meio do Reator IEA-R1 de 4,5 MW, fluxo de nêutrons térmicos médio de 4,71 x 1013 ncm-2s-1, para suprir uma demanda existente em empresas de END e inspeções, e pelo próprio Centro de Tecnologia das Radiações, no IPEN/CNEN-SP. O sistema de irradiação (SI) é constituído por uma cápsula de irradiação em alumínio, linhas de transferência, válvulas agulhas, conexões anilhadas, conectores rápidos, manovacuômetro, sistema de vácuo, dewar de liquefação, blindagem em chumbo, cilindros de armazenamento e transporte (CAT), dentre outros. O SI foi aprovado nos testes de estanqueidade e estabilidade (testes de formação de bolhas, pressurização, evacuação e com equipamento leak detector SPECTRON 600 T). Na produção experimental para obtenção de 1,07x1011 Bq (2,9 Ci) de 41Ar, distribuíram-se dosímetros de alanina em diversos componentes e dispositivos do SI. Além disso, determinaram-se as taxas de exposição na parede da blindagem em chumbo, ao concentrar o gás radioativo liquefeito e no CAT, após a transferência do 41Ar, pelo medidor de radiação portátil Teletector ® Probe 6150 AD-t/H.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Le centre de recherche ArcelorMittal de Montataire développent de nouvelles solutions acier innovantes associant métal et polymère. Pour les ailes de voiture, le composite retenu est un matériau multicouche composé d’une lame d’acier sur laquelle est déposé un film mince de polypropylène choc chargé avec des particules minérales par l’intermédiaire d’une fine couche de polypropylène fonctionnalisé par le greffage d’anhydride maléique. Afin de prévoir et de connaitre le comportement de la partie organique du matériau lors de sa mise en forme par emboutissage et à posteriori de prédire l’état de ses propriétés mécaniques lors de son utilisation, la détermination des lois de comportement mécanique vrai et intrinsèque sur le modèle de la loi G’sell et Jonas est nécessaire. Ces lois sont définies selon trois chemins de déformation : la traction uniaxiale, le cisaillement simple et la traction plane. Les micromécanismes de déformation de la microstructure semi-cristalline des différentes formulations des matériaux selon leur mode de sollicitation mécanique ont été étudiés. Les résultats obtenus Post Mortem et In Situ ont permis la description qualitative et quantitative des évolutions des principales modifications microstructurales. Ces dernières diffèrent avec l’ajout de charges minérales. Deux nouvelles méthodes, la Tomographie X et la spectroscopie Raman permettent la détermination de la déformation volumique dans le cas de matériau de géométrie fine (300 µm). Le retrait lors d’un cycle thermique est étudié. Les influences du chauffage, de la formulation et de la microstructure (orientation des chaînes macromoléculaires et endommagement volumique) sont décrites
The ArcelorMittal research centre of Montataire elaborates innovative steel / polymer products. In the case of automotive fenders, the composite is a multilayered material. A thin impact polypropylene film is laminated on steel using a thin layer of a functionalized polypropylene. Mineral particles are added to improve stiffness. In order to predict and understand the behaviour of the organic layer all along its production process and finally to be able to characterize the state of its mechanical properties in use, the determination of the true and intrinsic mechanical behaviour laws according to the G’sell and Jonas model is necessary. These laws are obtained for three different mechanical paths: uniaxial tensile, simple shear and plane tensile. The deformation micromechanisms of the impact polypropylene semi-crystalline microstructure which depend on the materials formulations and on the mechanical path used are studied. Post Mortem and In Situ results give qualitative and quantitative description of the main microstructural modifications. Two new methods, X Tomography and Raman spectroscopy allow the quantification of the volume deformation which is developed during tensile tests. They are mainly available for very thin samples. X radiography and VideoTraction™ are not suitable anymore for this kind of geometry. Finally, the thermo-mechanical phenomenon of shrinkage which occurs during thermal treatment above the material melting point is analysed. Influences of the heating conditions, of the material formulations and of the material microstructure are described. Special overviews are done on the macromolecular chains orientation and on the volume damage influences

Etat de degradation en fonction du temps d'un materiau soumis a des sollicitations thermomecaniques sur des plaques unidirectionnelles et des tubes (esais, traction, fluage, eclatement, flexion). Utilisation d'emission acoustique pour suivre l'evolution de la structure. Cinetique d'endommagement

Etude experimentale (essais de fatigue, essais de traction, de compression) sur des eprouvettes entaillees ou non, trouees ou non de stratifies resine epoxyde/carbone. Analyse mathematique avec des calculs par elements finis

Etat des connaissances sur le polyamide-11 et les RILSAN commerciaux; vieillissement modélisé du RILSAN; vieillissement accéléré du RILSAN; analyse de gaines internes vieillies sur site d'exploitation

Les chantiers de maintenance et d’assainissement dans les centrales nucléaires nécessitent la mise en place d’enceintes ventilées autour des zones contaminées afin de limiter la propagation de la contamination à l’environnement extérieur. L’air rentre dans l’enceinte aux travers d’ouvertures sous la forme d’un écoulement directionnel, orienté de l’extérieur vers l’intérieur, assurant ainsi le confinement dynamique. En raison des opérations qui se déroulent à l’intérieur de l’enceinte et des perturbations externes, il est possible que l’écoulement de confinement dynamique aux ouvertures soit perturbé et subisse des inversions locales et instationnaires, conduisant ainsi à transporter la contamination à l’extérieur de l’enceinte. La présente étude s’intéresse aux petites ouvertures de type fentes minces rectangulaires où l’écoulement au droit de celles-ci est généralement turbulent. Les principaux objectifs de la thèse sont d’une part d’identifier les conditions aérodynamiques susceptibles de produire le phénomène de rétrodiffusion aux ouvertures, d’autre part d’évaluer la capacité des approches de modélisation de la turbulence URANS et LES à reproduire les instabilités liées à ce type d’écoulement. Il a été montré que l’apparition du phénomène de rétrodiffusion est principalement liée à la présence d’une perturbation aéraulique additionnelle, de type jet turbulent ou sillage, en compétition avec l’écoulement initial de confinement dynamique. Des expériences de traçage gazeux ont été mises en place sur une maquette expérimentale dans le but de quantifier la rétrodiffusion en fonction des différentes conditions aérauliques à l’ouverture et des caractéristiques de celle-ci. Des visualisations des écoulements à l’ouverture ont également été réalisées à l’aide d’un dispositif de tomographie laser. Enfin, l’analyse des résultats des simulations CFD a démontré que les approches de type RANS ou URANS ne permettaient pas de reproduire les instabilités de l’écoulement conduisant au phénomène de rétrodiffusion, contrairement aux simulations des grandes échelles de la turbulence (LES) qui reproduisent fidèlement les structures locales et instantanées à l’origine du phénomène.

Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. Validation of the tracking performance is often done in staged traffic scenarios, where additional sensors, mounted on the vehicles, are used to obtain their true positions and velocities. The difficulty of evaluating the tracking performance complicates its development. An alternative approach studied in this thesis, is to record sequences and use non-causal algorithms, such as smoothing, instead of filtering to estimate the true target states. With this method, validation data for online, causal, target tracking algorithms can be obtained for all traffic scenarios without the need of extra sensors. We investigate how non-causal algorithms affects the target tracking performance using multiple sensors and dynamic models of different complexity. This is done to evaluate real-time methods against estimates obtained from non-causal filtering. Two different measurement units, a monocular camera and a LIDAR sensor, and two dynamic models are evaluated and compared using both causal and non-causal methods. The system is tested in two single object scenarios where ground truth is available and in three multi object scenarios without ground truth. Results from the two single object scenarios shows that tracking using only a monocular camera performs poorly since it is unable to measure the distance to objects. Here, a complementary LIDAR sensor improves the tracking performance significantly. The dynamic models are shown to have a small impact on the tracking performance, while the non-causal application gives a distinct improvement when tracking objects at large distances. Since the sequence can be reversed, the non-causal estimates are propagated from more certain states when the target is closer to the ego vehicle. For multiple object tracking, we find that correct associations between measurements and tracks are crucial for improving the tracking performance with non-causal algorithms.

Thesis (M.P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 2008.
Source: Masters Abstracts International, Volume: 46-06, page: 3250. Adviser: George L. Delclos. Includes bibliographical references.

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy
Background Silicosis rates in gold miners in South Africa are very high but there have been no analyses of long term trends. While much research has been conducted on occupational respiratory disease in gold, asbestos and coal miners, little is known about the respiratory health of miners of other commodities, such as diamonds and platinum, two of the most important minerals in South Africa. The ore bodies from which minerals are mined often contain other „incidental‟ minerals and compounds that may cause disease. Aims The aims of this thesis were to conduct the first ever analysis of silicosis trends in black and white gold miners over a 33-year period; to discuss the role of oscillating migration in the high rates of silicosis; and to explore the potential for workers in the diamond and platinum mining sectors to develop occupational respiratory diseases. Methods Gold, diamond and platinum mine workers were identified from the PATHAUT autopsy database at the National Institute for Occupational Health. Trends in silicosis from 1975 to 2007 were calculated separately for black and white gold miners because of differences in exposure, patterns of employment and autopsy referral patterns. The role of oscillating migration in the silicosis epidemic was explored. Diamond mine workers with asbestos-related diseases at autopsy and platinum mine workers with silicosis and/or fibrotic nodules in the lymph nodes were identified. Supplementary data from other sources were reviewed to viii exclude all those who might have been exposed to asbestos or silica, respectively, outside of the mining sector in which they worked. Asbestos lung burdens were calculated for the case series of diamond miners and mine tailings and soil samples were examined for asbestos fibres, using scanning electron microscopy. Findings The proportion of white miners with silicosis increased by 17% (from 18% to 22%) over the 33-year study period. That of black miners increased 10-fold (from 3% to 32%), primarily due to the aging workforce and increasing periods of employment. Adjusted odds ratios for silicosis increased with year of autopsy for black miners. Oscillating migration has also played a major role in the silicosis epidemic. Evidence indicates that diamond mine workers are at risk for developing asbestosrelated diseases and that platinum mine workers are at risk for developing silicosis. Conclusion The gold mines have failed to control silica dust levels adequately and prevent disease in mine workers. The sparsity of available dust measurements and poorly documented work histories are major obstacles to conducting occupational health research in South Africa; attention and legislation needs to be focused urgently on these areas. The PATHAUT database is the only occupational respiratory disease database in South Africa that can be used for disease surveillance, trend analyses and research in all mining sectors.

Industry 4.0 has transformed the manufacturing industry into a new paradigm causing numerous changes in the models of business and process automation. The profound change in the context of production has brought the issue of efficiency. Some of the key technologies that emerged to tackle this issue are Big Data, Internet of Things (IoT), Digital Twins, Artificial Intelligence, Machine Learning, Augmented Reality and Additive Manufacturing. This revolution has not remained within the borders of the manufacturing field but it pushes changes in a lot of fields; in particular, it has introduced health care delivery to the dawn of a foundational change into the new era of smart and connected health care, referred to as Healthcare 4.0. Although automation and assistance technologies are becoming more prevalent in production and logistics, there is consensus that humans remain an essential part of operations systems bringing to the definition of Human-centered Industry 4.0. Nevertheless, human factors are still underrepresented in the research stream resulting in an important research and application gap. This Ph.D. thesis proposes a set of innovative work-flows for real systems based on enabling technologies of Industry 4.0 and Healthcare 4.0 that can enhance and complement the human in manufacturing and healthcare. The work is trying to fill a portion of the gap between research and application concerning the Human factor in Industry 4.0 and propose new solutions that increase efficacy, flexibility and cost-effectiveness of healthcare services focusing especially on movement disorders rehabilitation. This thesis is composed of four chapters. The first Chapter provides an introduction to the reference context. Chapter 2 describes the state of the art of Industry 4.0, its challenges and technologies with a focus on the Human factor and reports the contribution of the usage of Industry 4.0 enabling technologies to provide new solutions for maintenance training, process quality assessment and bio-mechanical risk detection. Chapter 3 introduces the Healthcare 4.0 going into detail about new rehabilitation protocols for movement disorders; it shows work for signal processing, focusing on the application of undercomplete autoencoders for surface electromyography analysis and evaluation of cueing technique efficacy for Parkinson's Disease rehabilitation. The study cases and the contributions reported in this thesis were always compared with standard techniques. Finally, the conclusions about the research works and future research propose.

Background and Purpose Low socioeconomic status (SES) populations as well as minorities are often exposed to a disproportionate number of hazardous chemical including hydrogen fluoride, benzene and formaldehyde (Bullard, 2008). The sources of these hazards may include noxious land uses such as incinerators and landfills, Superfund sites, Toxic Release Inventory (TRI) facilities, sewer and water treatment plants, and other locally unwanted land uses (Choi, Shim, Kaye, & Ryan, 2006). The disproportionate burden often results in increased exposure to harmful environmental conditions for affected communities (Wilson et al., 2014). The objectives of this study are to evaluate the relevance of demographic characteristics to (1) TRI facility location, (2) TRI chemical emissions, and (3) incidence and resolution of facility complaints. Methods The study area is the Atlanta Metropolitan Statistical Area (MSA), designated by the United States Office of Management and Budget is comprised of 20 counties. Multivariate logistic regression was used to assess the relative importance of race and socioeconomic variables in predicting whether a TRI facility was located in a census tract. We applied multiple regression models to examine the association between amount of air toxics released from TRI facilities in the census tract (dependent variable), the number of emissions from TRI facilities in the census tract and the amount of chemicals released per emission and socio-demographic variables at the census tract level. Additionally, multivariate ordinal logistic regression was used to evaluate the association between the number of complaints to toxic chemicals and time to resolution of complaints and the covariates (SES and race/ethnicity) at the census tract level. Results In multivariate models the odds ratio for the presence of a TRI facility is 0.89 (p=0.002) for each 1% increase of females with a college degree and 2.4 (p Discussion and Conclusion We found evidence of racial and socio-demographic disparities in the burden of TRI facilities and chemical emissions in the Atlanta MSA. We observed a trend for toxic chemicals emitted suggesting that more blacks and Hispanics were burdened by and potentially exposed to TRI facilities than were Whites. There was only one predictor, percentage of females with a college degree, where we observed an inverse and statistically significant association with the amount of chemical emissions in pounds. We also found evidence that of potential differences in regulation processes of TRI facilities. Overall, results indicate that race/ethnicity and socioeconomic composition play a role in TRI facility siting and TRI facility emissions indicating burden disparities for low-SES populations as well as non-Whites in the Atlanta MSA. These results are similar to results presented in the environmental justice literature.

Lung cancer currently leads the cancer-related mortality rate worldwide. It is a highly incident, invasive and metastatic cancer. Cancer treatment is usually ensured by the combination of surgery, and adjuvant therapies (chemo- and radiotherapy). However, this approach presents problems in terms of efficacy, toxicity to peripheral tissues and resistance. These limitations associated with the occurrence of bacterial respiratory tract infections (IBTR) promote the ineffectiveness of cancer treatment, leading to high mortality and morbidity. In recent years there has been an effort to produce a new generation of compounds that fill these clinical gaps, but the results are still not satisfactory. Thus, the search for new natural compounds that evidence anticancer and/or antimicrobial activity is crucial. In this context, microorganisms constitute a rich source of bioactive compounds, due to their secondary metabolism developed in response to stress conditions, ensuring their survival/resilience. Extreme and/or under-exploited environments, such as caves, sustain microorganisms with high biotechnological potential. Thus, the objectives of this work were: (1) to make the state of the art on lung cancer, BTRI associated with it, available treatments and the discovery of new natural compounds with therapeutic value; (2) present an unprecedented review of calcareous karstic caves, the microbial habitats it sustain and the biotechnological power of these microorganisms for industrial, environmental and medical applications; (3) screening the antimicrobial and anticancer activity of bacteria isolated from under-exploited environmental niches. Archaea and Bacteria in karst caves underwent an evolution under selective pressures, thus developing a highly specialized biosynthetic metabolism and sustained by a peculiar genetic diversity. In particular, karst cave bacteria and archaea have the ability to synthesize enzymes adapted to low temperatures, as well as have a very attractive resistome and parvome for biotechnological applications. The screening for the bioactivity of bacteria isolated from limestone caves demonstrated its antimicrobial potential against BTRI-promoting bacteria (live colony and crude extract assays). In addition, some of the extracts from different fractions of bacterial culture (mostly Pseudomonas spp.) showed anticancer activity, since the cellular activity of lung cancer cells was decreased/inhibited. This study contributes to the search for natural compounds that may be useful in the fight against lung cancer in the futur
O cancro do pulmão lidera atualmente a taxa de mortalidade associada a cancro, à escala mundial. É um cancro altamente incidente, invasivo e metastizante. O tratamento do cancro é normalmente assegurado pela combinação de cirurgia, e terapias adjuvantes (quimio- e radioterapia). No entanto, esta abordagem apresenta problemas em termos de eficácia, toxicidade para tecidos periféricos e resistência. Estas limitações associadas à ocorrência de infeções bacterianas do trato respiratório (IBTR) fomentam a ineficácia do tratamento do cancro, conduzindo a elevada mortalidade e morbidade. Nos últimos anos tem havido um esforço para produzir uma nova geração de compostos que colmatem estas lacunas clínicas, mas os resultados ainda não são satisfatórios. Assim, a busca de novos compostos naturais que evidenciem atividade anticancerígena e/ou antimicrobiana é premente. Neste contexto, os microorganismos constituem uma rica fonte de compostos bioativos, graças ao seu metabolismo secundário desenvolvido em resposta a condições de stress, para garantir a sua sobrevivência/resiliência. Ambientes extremos e/ou sub-explorados, como as grutas, sustentam microorganismos com elevado potencial biotecnológico. Assim, os objetivos deste trabalho consistiram em: (1) fazer o estado da arte sobre o cancro do pulmão, IBTR a ele associadas, tratamentos disponíveis e a descoberta de novos compostos naturais com valor terapêutico; (2) apresentar uma inédita revisão acerca de grutas Cársicas calcárias, os habitats microbianos que sustentam e o poder biotecnológico desses microorganismos para aplicações industriais, ambientais e médicas; (3) realizar o rastreio da atividade antimicrobiana e anticancerígena de bactérias isoladas de nichos ambientais sub-explorados. Archaea e Bacteria em grutas Cársicas sofreram uma evolução sob pressões seletivas, desenvolvendo assim um metabolismo biossintético altamente especializado e sustentado por uma diversidade genética peculiar. Em particular, têm capacidade de sintetizar enzimas adaptadas a temperaturas baixas, assim como possuem um resistoma e parvoma muito atraentes para aplicações biotecnológicas. O rastreio da bioatividade de bactérias isoladas de grutas calcárias demonstrou o seu potencial antimicrobiano contra bactérias promotoras de IBTR (ensaios com colónia viva e extratos brutos). Além disso, alguns dos extratos de diferentes frações de cultura bacteriana (Pseudomonas spp.) apresentaram atividade anticancerígena, uma vez que a atividade de células de cancro do pulmão de rato (Lewis lung cancer) foi diminuída/inibida. Este estudo constitui um contributo na procura de compostos naturais que futuramente possam servir no combate ao cancro do pulmão.
Mestrado em Biologia Molecular e Celular