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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Attainment of Low Levels of Muscle Tension: Biofeedback-Assisted/Cue-Controlled Relaxation and Biofeedback Training Compared

Ewing, Jack Winston 08 1900 (has links)
Cue-controlled relaxation appeas to have several advantages over prominent anxiety-reduction treatments. It does not require the formulation of conditioned stimulus hierarchies nor the use of mental imagery as does systematic desensitization nor the application of noxious stimularion (farradic shock) utilized in anxiety relief. However, its efficacy, in quantitative terms, has not been determined. The present study compared the effectiveness in attainment of relaxation of instructional set, biofeedback training, and biofeedback-assisted/cue-controlled relaxation training procedures. Results indicate that cue-controlled relaxation training was more effective in terms of mean level of frontal is EMG and degree of maintenance of low EMG levels than either biofeedback training or instructions.
172

Chemical Aversion Therapy for Morphine Addiction

Norton, Carole Lynn 12 1900 (has links)
These studies led the experimenter to investigate the use of chemical aversion therapy using anectine as the aversive stimulus with a morphine addict. The success of Thomason and Rathod with heroin addicts suggested that their experimental method would be useful as a reference while designing this study. The treatment hypothesis was that the patient's use of intravenous narcotic drugs would be eliminated through the application of chemical aversion therapy. Chemical aversion therapy was operantly defined as the injection intravenously of anectine into the patient concurrent with his self-injection of his narcotic of choice.
173

Impact des procédés de transformation sur le devenir digestif des protéines de la viande / Impact of technological treatments on digestive future of meat proteins

Bax, Marie-Laure 13 June 2012 (has links)
Les protéines carnées apportent tous les acides aminés indispensables, en quantité équilibrée par rapport aux besoins de l'Homme. La viande étant également une bonne source de vitamine B12 et de fer, son potentiel nutritionnel est très élevé. Ce potentiel pourrait cependant être modulé 1) par une digestion des protéines plus ou moins complète dans l'intestin grêle, déterminant la quantité d'acides aminés absorbés, 2) par une vitesse de digestion plus ou moins élevée, influençant la capacité d'assimilation des acides aminés absorbés. Les procédés de transformation impliqués dans la préparation des viandes peuvent générer des modifications physicochimiques des protéines. Leurs conséquences sur la mise à disposition des acides aminés constitutifs ont été peu étudiées. Après avoir déterminé l'impact des opérations unitaires de transformation de la viande sur les caractéristiques biochimiques et structurales des protéines, les conséquences sur les paramètres de digestion ont été étudiées, in vitro, sur des extraits myofibrillaires, et in vivo en utilisant le miniporc comme modèle animal. L'approche protéomique est utilisée, en parallèle, pour comparer la composition de muscles de porcs issus de modes d'élevage différents et étudier les corrélations avec la digestion. Plusieurs marqueurs protéiques des paramètres de digestion in vitro sont trouvés sur la viande maturée et cuite, et sont liés au processus de détoxification et de contraction musculaire. La cuisson est le procédé qui a le plus d'impact sur les caractéristiques du produit prêt à consommer, l'application de températures croissantes se traduisant par une combinaison progressive de dénaturation, d'oxydation puis d'agrégation des protéines. Le développement d'un modèle de digestion in vitro, sur des protéines myofibrillaires, a permis d'étudier les différents paramètres de digestion pour les différents procédés. Maturation et hachage ont eu peu d'effets sur ces paramètres. Par contre, par rapport à la viande crue, la vitesse de digestion est supérieure pour une température de cuisson de 70°C, ce qui n'est plus le cas à partir de 100°C. Inversement le potentiel de dégradation maximale est plus élevé pour des températures supérieures à 100°C. La mise en relation des caractéristiques de la viande, avec les paramètres de digestion, suggère que pour des températures de cuisson de l'ordre de 70°C, la dénaturation des protéines favorise une dégradation rapide des protéines en accroissant l'accessibilité des sites de coupure pour les enzymes digestives, mais que pour des températures supérieures, l'oxydation conduit à des agrégats qui limitent cette accessibilité. L'étude in vivo, sur le miniporc, a confirmé cette hypothèse, la vitesse d'apparition des acides aminés dans le sang, suite à l'ingestion des viandes étant supérieure pour une température de cuisson à coeur de 75°C, par rapport à des cuissons à 60 ou 95°C. Par contre contrairement à ce qui était observé in vitro, l'utilisation de viande marquée avec un isotope stable (15N), nous a permis de montrer que la température de cuisson n'affecte pas la quantité totale de protéines digérées dans l'intestin grêle (environ 95% des protéines ingérées). En conclusion, parmi les opérations unitaires impliquées dans la préparation des viandes, la cuisson semble être celle qui influence le plus la digestion des protéines. L'équilibre entre les processus de dénaturation et d'oxydation des protéines en fonction de la température de cuisson semble être un point clé dans la détermination de la vitesse de digestion des protéines. Ce paramètre est important notamment dans le cadre de la nutrition des personnes âgées. Par contre, les compensations au cours des étapes de la digestion font que ces différences de vitesses ne se traduisent pas par des différences de digestibilité dans l'intestin grêle. / In France, meat consumption represents one third of the total protein intake. Meat proteins have a high content of well-balanced essential amino acids near to Human needs. Meat is also a good source of vitamins B12 and iron. Its nutritional potential is thus very higher, but it could be modulated 1) by a protein digestion in the small intestine more or less complete (digestibility), determining the amount of absorbed amino acids, 2) by a speed of digestion higher or lower, affecting the postprandial utilization of absorbed amino acids in protein metabolism. Technological treatments involved in the meat preparation can generate physical-chemical changes of protein. Their impacts on the availability of constitutive amino acids (quantity, kinetics) have been little studied. After determining the impact of unitary operations on meat processing (aging, mincing, cooking) on the biochemical and structural characteristics of proteins, the effect on digestion parameters were studied in vitro on myofibrillar extracts, and in vivo using the minipig as an animal model. The proteomic approach is used in parallel to compare the composition of pig muscles from different rearing methods and study the correlations with digestion. Several protein markers of in vitro digestion are found for both aged and cooked meat, linked to detoxicant process and muscle contraction. The cooking is the process that has the greatest impact on characteristics of "ready-to-eat" product, the application of increasing temperatures (70, 100 and 140°C) resulting in a progressive combination of denaturation, oxidation and then of protein aggregation. Development of an in vitro digestion model (pepsin alone or coupled with trypsin/α-chymotrypsin), on myofibrillar proteins, was used to study the various parameters of digestion (initial slope, maximum rate, time to maximal rate, half-life time and maximal degradation) for the different processes. Aging and mincing have little impacts on these parameters. However, compared to raw meat, the rate of digestion is higher for a cooking temperature to 70°C, which is no longer the case for temperatures above 100°C. Conversely, the potential of maximal degradation is higher for temperatures above 100°C. Linking characteristics of meat with digestion parameters, suggests that for cooking temperatures of around 70°C, denaturation of proteins promotes rapid degradation of proteins by increasing the accessibility of digestive enzymes to their cutting sites, but for higher temperatures, oxidation leads to aggregates that limit accessibility. In vivo study on the minipig, confirms this hypothesis, the rate of appearance of amino acids in the blood following meat ingestion is higher with a core cooking temperature to 75°C, compared to cooking with 60 or 95°C. Furthermore, contrary to what observes in vitro, the use of meat labeled with a stable isotope (15N), we show that the cooking temperature are not affect the total amount of digested proteins in the small intestine (about 95% of ingested proteins). In conclusion, among the unitary operations involved in the preparation of meat, the cooking seems to be the one that most influence the digestion of proteins. The balance between the denaturation processes and protein oxidation according to the cooking temperature appears to be a key point in determining the speed of proteins digestion. This parameter is particularly important in the context of elderly nutrition. As it does not impact on the protein digestibility in the small intestine, the cooking temperature appears as an interesting lever to modulate the speed of meat protein digestion, according to the targeted consumer.
174

Komparácia efektivity zotavenia na zmenu rychlostných a silových indikátorov u softbalistiek / Comparison to efficiency of recovery due to the change of speed and strenght indicators of women softball players

Sidorová, Veronika January 2016 (has links)
Title of thesis: Comparison to efficiency of recovery due to the change of speed and strenght indicators of women softbal players Compiled by: Bc. Veronika Sidorová Supervisor: PaedDr. Tomáš Malý, Ph.D. Objectives: The aim is to compare the efficiency of recovery in two regeneration procedures to change the speed and power indicators in extra league softbal player wore a short-motor performance. Methodology of work: The object of the study was 14 extra league softball player wore for which we have found with two wellness services (sports massage, cold water) effect on their speed and power indicators before load after load after one of the above procedures Types of motor test applied to the surveyed sample: 1.Linear sprint to 10 meters of semi-tall launch Stress test applied to the surveyed sample: 1.Load model for isokinetic dynamometer to Humac Norm (power-muscle contraction) The results: The results of the motor and the load test, we found that the stress occurred in the analysis focused on the decrease of muscular strength, but on each regeneration procedures, a significant improvement in performance even if not on the original values. Powered by TCPDF (www.tcpdf.org)
175

[en] EXPERIMENTAL STUDIES OF DIFFERENT SURFACE TREATMENTS APPLIED TO TITANIUM DENTAL IMPLANTS / [pt] ANÁLISE DE DIFERENTES PROCESSOS SUBTRATIVOS UTILIZADOS NO TRATAMENTO DA SUPERFÍCIE DE IMPLANTES ODONTOLÓGICOS DE TITÂNIO CP

RICARDO VIEIRA BATHOMARCO 12 April 2004 (has links)
[pt] Apesar do titânio e suas ligas serem amplamente empregadas na implantodontia e os resultados das experiências clínicas comprovarem que estes materiais apresentaram excelente biocompatibilidade, existem dúvidas quanto às propriedades físico-químicas ideais das superfícies dos implantes de titânio para se obter uma osseointegração adequada. Todavia, os padrões para definir as propriedades superficiais dos implantes odontológicos ainda não estão definidos na literatura. Estas características são importantes, uma vez que a osseointegração é fortemente dependente da ligação das células com a superfície do implante. Este trabalho tem como objetivo analisar três processos subtrativos utilizados no tratamento da superfície de implantes osseointegráveis de titânio comercialmente puro a saber: abrasão - jateamento, erosão - ataque químico e combinação das duas. Estes métodos permitem avaliar as propriedades físicas e químicas superficiais de cilindros de titânio tratados através destes processos tais como: morfologia superficial, topografia e molhabilidade (ângulo de contato). Foi possível, também, identificar os parâmetros e métodos vinculados que otimizam as condições superficiais para este fim. / [en] Titanium alloys are widely used in dental implants in virtue of clinical evidences of the excellent biocompatibility performance shown by this alloys. However, there are still a number of unanswered questions regarding the ideal physicochemical properties of titanium surfaces used in dental implants aiming at an appropriate integration with the bone. Furthermore, in the literature there are not still available standards defining superficial properties of dental implants. These characteristics are a fundamental importance since biocompatibility is strongly depended upon the connections between host cells and the titanium surface implant. The present work has as objective the analysis of three processes use for surface treatments of dental implants based on titanium of commercial purity, namely mechanically- induced erosion, chemical etching and the combination of both. Such methods applied to titanium cylinders, have permitted one to estimate more closely their physical and chemical surfaces properties, such as surface morphology, surface topology and contact angle (wet ability). It is also identified the factors and methods allowing to obtain the optimal surface conditions for this purpose.
176

[en] MICROSTRUCTURAL EVALUATION OF API5LX80 STEELS SUBJECT TO DIFFERENT COOLING RATES / [pt] AVALIAÇÃO MICROESTRUTURAL DE AÇOS DA CLASSE API5LX80 SUBMETIDOS A DIFERENTES CICLOS TÉRMICOS

ADRIANA DE ALMEIDA HALFELD VIEIRA 20 August 2008 (has links)
[pt] Nesse trabalho foi realizada uma avaliação microestrutural da influência do ciclo térmico em três aços da classe API5LX80: Nb-Cr, Nb-Cr-Mo e Nb-Cr-Mo-V fabricados no Brasil. Estes aços foram fabricados através de processo termo-mecânico controlado sem passarem por uma etapa subseqüente de resfriamento acelerado. Foi realizada uma caracterização microestrutural em duas condições, pós- laminação e austenitização a 900oC seguida de três (3) ciclos térmicos: resfriamento ao ar (1,5oC/s), ao óleo (30oC/s) e a água (115oC/s). Na condição de pós-laminado, os aços Nb-Cr, Nb-Cr-Mo, e Nb-Cr-Mo-V não apresentaram diferenças significativas quanto ao TG, distribuição de fases (ferrita, bainita e AM), dureza e microdureza mas foram verificadas diferenças em suas subestruturas (subgrãos, células e precipitação fina) observada em MET. Concluise que a inclusão de Mo e V nos aços Nb-Cr-Mo e Nb- Cr-Mo-V não ocasionou influência a nível microestrutural, mas ocasionou mudanças a nível subestrutural verificadas em MET que talvez possam justificar a diferença entre propriedades mecânicas.Verificamos a diminuição do tamanho de grão com o aumento da taxa de resfriamento nos aços Nb- Cr, Nb-Cr-Mo, e Nb-Cr-Mo-V. Os valores de dureza e microdureza são os mesmos para os aços Nb-Cr e Nb-Cr-Mo na condição de após aplicação dos ciclos térmicos, e uma associação pode ser feita com a quantidade de fases de cada um, pois a distribuição quantitativa das fases para ambos os aços é muito similar. O aço Nb-Cr-Mo-V apresenta uma distribuição diferente, com a formação da fase martensítica já no resfriamento ao óleo (30oC/s) e o aumento da quantidade desta fase a medida que a taxa de resfriamento diminui. / [en] The present work presents a microstructural evaluation of three different chemical compositions of API5LX80 classified as Nb-Cr, Nb-Cr-Mo e Nb-Cr- Mo-V steel in two conditions, as received and after three applied cooling rates: air-cooled (1,5oC/s), oil-cooled (30oC/s) e water- cooled (115oC/s). This material under study is a microalloyed HSLA steel used for pipeline purposes produced in Brazil. Usually this steel is processed by thermo- mechanical controlled hot rolling followed by accelerated cooling. However, the material under study was not accelerated cooled after thermo-mechanical controlled hot rolling. Instead, chemical composition was changed to obtain similar mechanical properties of this class of steel. The Nb-Cr, Nb-Cr-Mo, e Nb-Cr-Mo-V as-received steels studied in this work presented the same quantitative distribution of grain size and volumetric fraction of the phases (ferrite, bainite and MA), as well as, the same hardness Rockwell (HRB) and Vickers (HV100). However, the substructures (subgrains, cells and fine precipitation) of the three steels were different when examed in Transmission Electron Microscopy - TEM. The Nb-Cr, Nb-Cr- Mo, e Nb-Cr-Mo- V steels, after submitted to the three cooling rates, presented a decrease in grain size with the increasing of the cooling rate. The same hardness Rockwell (HRB) and Vickers (HV100) values were found for Nb-Cr e Nb- Cr-Mo steels and this fact can be associated to the volumetric fraction of both steels, because both have very similar phase distribution. The Nb-Cr-Mo-V steel presented a different phase distribution with increased of martensite as the cooling rate decreases.
177

"Avaliação de camadas de carbonetos e de boretos produzidas nos aços AISI H13 e D2 por meio de tratamentos termo-reativos" / EVALUATION OF CARBIDE AND BORIDE LAYERS PRODUCED ON AISI H13 AND D2 STEELS BY THERMO-REACTIVE TREATMENTS

Oliveira, Carlos Kleber Nascimento de 06 April 2006 (has links)
Neste trabalho, camadas de elevadas durezas e resistentes ao desgaste, constituídas de NbC, VC ou Fe-B, foram produzidas nos aços AISI H13 e D2, por meio de tratamentos termo-reativos em banhos de bórax, com adição de Fe-Nb, Fe-V, Fe-Ti e Al. As amostras foram caracterizadas por meio de microscopias ótica e eletrônica de varredura com EDS (espectroscopia de dispersão de energia), difração de raios-X, GDOS (“Glow discharge optical spectroscopy"), microdureza Vickers, e ensaios de adesividade e desgaste em micro-escala. Para os banhos contendo Fe-Nb/Al, foram obtidas camadas de NbC nos dois aços, com espessuras médias de 6,2 mícrons, quando produzida no aço AISI H13, e 15,6 mícrons para o aço AISI D2. No caso do banho com adição de Fe-V/Al, produziram-se camadas de VC, com espessuras médias de 5,8 e 14,2 mícrons, para os aços AISI H13 e D2, respectivamente. As durezas das camadas de NbC e VC situaram-se na faixa de 2338 a 2471HV. No caso dos banhos contendo Fe-Ti e Al ou apenas Al, foram produzidas camadas de boretos, principalmente FeB e Fe2B, com espessuras variando de 30 a 130 mícrons, e durezas médias na faixa de 1583 a 1742HV. Os ensaios de adesividade evidenciaram as excelentes aderências das camadas com os substratos. Todas as camadas apresentaram resistências ao desgaste muito superiores as dos substratos, destacando-se as camadas de NbC e VC. Os ensaios de desgaste em micro-escala foram realizados sob carga elevada e sem uso de abrasivo, simulando condições de desgaste adesivo-abrasivo, uma vez que inexistem dados a respeito desse comportamento. Com o decorrer do ensaio, o modo de desgaste passou de adesivo para abrasivo, o que foi registrado pela presença de sulcos paralelos e de superfícies polidas nas calotas de desgaste. / In the present work, hard and wear resistant layers, consisting of NbC, VC or Fe-B, were produced on AISI H13 and D2 steels, by thermo-reactive treatments in borax baths, added with Fe-Nb, Fe-V, Fe-Ti and Al. Samples were characterized by optical and scanning electron microscopy, energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), Glow discharge optical spectroscopy (GDOS), Vickers microhardness, and adhesion and micro-scale wear tests. For the baths containing Fe-Nb/Al, the layers obtained on both steels consisted of NbC, with an average thickness of 6.2 micrometers, when formed on AISI H13 steel, and 15.6 micrometers for the AISI D2 steel. In the case of borax bath added with Fe-V/Al, the produced layers contained VC, which had average thicknesses of 5.8 and 14.2 micrometers, for the AISI H13 and D2 steels, respectively. The hardness of the NbC and VC layers varied from 2338 to 2471HV. In the case of the borax bath containing Fe-Ti and Al or only Al, boride layers were produced, mainly FeB and Fe2B, with depths ranging from 30 to 130 micrometers, and average hardnesses varying from 1583 to 1742HV. The obtained layers presented excellent adhesion to the substrates. All layers presented wear resistance superior to the substrates, mainly the NbC and VC layers. The micro-scale wear tests were performed under high applied loads and without addition of abrasive, thus simulating adhesive-abrasive wear conditions, as there is no existing data concerning this wear behavior. During the micro-scale wear test, the wear mode changed from adhesive wear to abrasive wear, which was verified by the presence of parallel grooves and smooth surfaces in the wear craters.
178

Caracterização da transformação martensítica em temperaturas criogênicas. / Characterization of the martensitic transformation at cryogenic temperatures.

Apaza Huallpa, Edgar 29 March 2011 (has links)
Na atualidade, o estudo da transformação martensítica é de grande importância na área acadêmica e tecnológica, devido à aplicação de aços e ferros fundidos com estruturas martensíticas. O estudo dos fenômenos da transformação martensítica envolve vários pesquisadores no mundo e é objeto de eventos como o ICOMAT e ESOMAT. O presente trabalho acompanhou a transformação martensítica por meio de técnicas experimentais a temperaturas sub-zero em um aço AISI D2 e uma liga Fe-Ni-C previamente austenitizadas. A literatura indica que o tratamento a temperaturas sub-zero pode melhorar propriedades dos aços temperados e revenidos. Foi explorado o uso dos métodos de ruído magnético de Barkhausen (MBN), para detectar a transformação de fase da austenita para a martensita durante o resfriamento sub-zero das amostras, usando três diferentes configurações: a emissão de ruído Barkhausen convencional estimulada por um campo magnético alternado; o método de Okamura que é a emissão de ruído magnético medido embaixo de um campo fixo (DC); e uma nova técnica experimental, que mede a emissão magnética espontânea durante a transformação na ausência de qualquer campo externo. Os fenômenos associados com a transformação de fase também foram medidos por resistividade elétrica e as amostras resultantes foram caracterizadas por microscopia óptica e eletrônica de varredura. Medições MBN no aço ferramenta AISI D2, austenitizadas a 1473K (1200C) e resfriadas a temperatura de nitrogênio líquido apresentaram uma mudança próximo de 225K (-48C) durante o resfriamento, que corresponde à temperatura Ms, como foi confirmado por medidas de resistividade. As medições da emissão de ruído magnético espontâneo, realizadas in situ durante o resfriamento da amostra imersa em nitrogênio líquido, mostraram que poderia ser detectado um fenômeno de estouro individual (burst), de forma similar às medições de emissão acústica (AE), o qual foi confirmado com a liga Fe-Ni-C. Este método de caracterização Spontaneous Magnetic Emission (SME) pode ser considerado uma nova ferramenta experimental para o estudo de transformações martensiticas em ligas ferrosas. Foi acompanhado o inicio da transformação martensítica por SME, em função do tamanho de grão, já que é conhecido pela literatura que o inicio da transformação martensítica (Ms), muda com a variação do tamanho de grão. / Martensitic transformations are of special interest both as an academic topic and as a technological issue, due to importance of steels and cast irons with martensitic structures. Studies of martensite transformation phenomena involve researchers all over the world and specific conferences and meetings, as ICOMAT and ESOMAT. The present work followed the martensitic transformation using different experimental techniques, during cooling at cryogenic temperatures samples of a AISI D2 cold work tool steel and also a Fe-Ni-C, previously austenitized. There are plenty of references in the literature suggesting that sub-zero cooling treatments could ameliorate the properties of quenched and tempered steels. The Magnetic Barkhausen Noise (MBN) method was applied during cooling to subzero temperatures of austenitic samples of a AISI D2 cold work tool steels (previously quenched from 1200ºC) and to a Invar-type Fe-Ni-C alloy. MBN is a non-destructive technique based on the detection of the signal generated when ferromagnetic materials are subjected to an oscillating external magnetic field. In order to study the austenite to martensite transformation, three different configurations were tested: conventional Barkhausen using an oscillating magnetic field, a method proposed by Okamura, which uses a fixed magnetic field and a new method that detects spontaneous magnetic emissions (SME) on the absence of any applied magnetic field. Other phenomena associated with the transformation were followed using electrical resistivity measurements, optical microscopy and X-ray diffraction. MBN measurements on a cold work tool steel AISI D2, austenitized at 1473K (1200ºC) and quenched to room temperature, made during further cooling to liquid nitrogen temperature, presented a clear change of signal intensity near 225K (-48ºC), corresponding to Ms temperature, as confirmed by resistivity measurements. The SME in situ measurements during cooling of samples in liquid nitrogen were able to detect single burst (landslide nucleation and growth) phenomena, in a manner similar to the Acoustic Emission (AE) measurements; these results have been confirmed also with measurements on a Fe-Ni-C alloy. The new Spontaneous Magnetic Emission (SME) characterization method can be considered a new experimental tool for the study of martensitic transformations in ferrous alloys. The beginning temperature for the martensitic transformation detected using SME, electric resistivity and MBN were compared with estimates using the Andrews empirical equation (linear, 1965) for the Ms temperature. The effect of the austenite grain size on the beginning of the martensitic transformation was studied using SME, as it is known that the Ms temperature depends on the austenite grain size.
179

"Estudos do desenvolvimento e caracterização das ligas Cu-Ni-Pt e Cu-Ni-Sn para fins eletro-eletrônicos" / STUDIES OF THE DEVELOPMENT AND CHARACTERIZATION OF THE Cu-Ni-Pt AND Cu-Ni-Sn ALLOYS FOR ELETRO-ELECTRONIC USES

Silva, Luis Carlos Elias da 04 October 2006 (has links)
O Cu e suas ligas têm diferentes aplicações na sociedade moderna devido as excelentes propriedades elétricas, condutividade térmica, resistência à corrosão dentre outras propriedades. Estas aplicações podem ser em válvulas, tubulações, panelas para absorção de energia solar, radiadores para automóveis, condutores de corrente e eletrônico, elementos de termostatos e partes estruturais de reatores nucleares, como, por exemplo, bobinas para campo toroidal para um reator de fusão nuclear. Dentre as ligas utilizadas em reatores nucleares, podemos destacar Cu-Be, Cu-Sn e Cu-Pt. O Ni e o Co, freqüentemente são adicionados às ligas de Cu para que a solubilidade seja deslocada para temperaturas mais elevadas com relação aos sistemas binários de Cu-Sn e Cu-Pt. A adição de Ni-Pt ou Ni-Sn ao Cu em porcentagens iguais ou inferiores a 1,5 % aliado a tratamentos termos-mecânico alteram as propriedades do Cu. Estudamos neste trabalho sete diferentes ligas: três ligas de Cu-Ni-Pt 1 (97,99 % Cu - 1,55 % Ni - 0,46 % Pt), 2 (99,33 % Cu - 0,23 % Ni -0,43 % Pt) 3 (98,01 % Cu - 0,48 % Ni - 1,51 % Pt); três ligas de Cu-Ni-Sn 4 (98,31% Cu - 1,12 % Ni - 0,58 % Sn), 5 (98,79 % Cu – 0,57 % Ni - 0,65 % Sn), 6 (98,39% Cu – 0,46 % Ni – 1,16 % Sn) e Cu eletrolítico 0 (0,0058 % Pb - 0,0007 % Fe - 0,0036 % Ni - 0,0024 % Ag). As referentes ligas foram desenvolvidas a partir de um forno a arco voltaico e passaram por tratamentos termo-mecânicos pré-determinados. As microestruturas foram analisadas diretamente por microscopia óptica e microscopia eletrônica de varredura / EDS e indiretamente por medidas de dureza Vickers e condutividade elétrica. O objetivo deste trabalho, portanto, foi observar e constatar os efeitos da mudança da microestrutura em relação às propriedades dureza e condutividade elétrica. / The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments.
180

Isolamento e seleção de microrganismos para remediação de efluente oleoso da indústria metal-mecânica / Isolation and selection of microorganisms for the oily effluent remediation of the metalworking industry

Queissada, Daniel Delgado 15 September 2009 (has links)
A indústria metal-mecânica é responsável pela síntese de um dos efluentes oleosos mais complexos e difíceis de tratamento e reuso. Esses efluentes são constituídos, entre outros poluentes, por fluidos de corte, que servem para refrigerar e lubrificar peças metálicas no sistema de usinagem. Quando esses efluentes são tratados biologicamente é importante que se faça isso com microrganismos autóctones do mesmo, pois o uso desses microrganismos (bioaumentação) tende a ser mais eficaz, uma vez que os mesmos já estão adaptados aos poluentes nele existentes. Com este propósito, o presente trabalho teve como objetivo principal o isolamento e seleção de microrganismos para remediação de um efluente metalmecânico através de tratamentos unitários em bioreator do tipo air-lift e por sistema oxidativo UV/H2O2, além do tratamento integrado com ambos os processos. No tratamento biológico foram utilizados os microrganismos autóctones do efluente estudado, além do uso do fungo Aspergillus niger como microrganismo de referência. A caracterização do efluente bruto mostrou que, em decorrência dos parâmetros determinados como, 1495 mg Pt/L de cor, DQO de 9147 mg/L, 53 mg/L de fenóis-totais, 15666 mg/L de ST, 2,5 mgO2/L de OD, 887 mg/L de O&G e fator de toxicidade crônica de 1667, o mesmo possui um alto potencial poluidor. Foram isolados, da amostra do efluente, seis possíveis tipos de fungos filamentosos. Dentre os quais, Epicoccum nigrum e Cladosporium sp, foram os que se mostraram mais eficazes para a realização do tratamento do efluente em reator do tipo air-lift. No biotratamento em reator airlift o fungo Epicoccum nigrum se mostrou mais eficaz na maioria das reduções dos parâmetros determinados (27% da DQO, 62% de fenóis-totais, 94% do H2O2, 44% da Cond. E e de 43% de O&G), já Cladosporium sp foi mais apto na redução de cor (87%). O tratamento oxidativo com sistema UV/H2O2, obteve reduções mais intensas, do que o tratamento biológico, em relação aos parâmetros de DQO (34%), H2O2 (98%) e no aumento de OD (705%) da amostra do efluente. Entretanto, foi menos eficaz nas reduções de cor (74%), fenóis-totais (24%), ST (15%) e Cond.E (34%) e atingiu um desempenho semelhante, em relação ao tratamento biológico, na redução de O&G (45%). Já o tratamento integrado do efluente por sistema UV/H2O2 seguido de tratamento biológico, propiciou uma intensificação nas reduções de todos os parâmetros avaliados pós-tratamento. Indicando assim que, o tratamento fotoquímico, antecipado ao tratamento biológico, aumentou a biodegradabilidade da amostra do efluente, facilitando desta forma a biorremediação do mesmo em reator air-lift. Entre os três sistemas de tratamento estudados (biológico, UV/H2O2 e UV/H2O2 - biológico), o processo integrado utilizando o sistema fotoquímico UV/H2O2 seguido do tratamento biológico com o fungo E. nigrum foi o mais eficaz para o efluente estudado. / The metalworking industry is responsible for one of the most complex and difficult to reuse and handling, oily effluents synthesis. These effluents are made by cutting fluids which provide refrigeration and purification of metallic pieces in the machining system. When these effluents are biologically treated is important to do this with autochthonous microorganisms, therefore the use of these microorganisms (bioaugmentation) tends to be more efficient because they are already adapted to the existing pollutants. The aim of this work was the isolation and selection of remediation microorganisms of metalworking effluent through unit processes (air-lift bioreactor and UV/H2O2 system) and also through their integration. In the biological treatment were used the autochthonous microorganisms from metalworking effluent beyond the use of Aspergillus niger as reference microorganism. The original effluent characterization presented a great pollutant potential. The value of color of the effluent was 1495 mg Pt/L, COD was 9147 mgO2/L, total phenols was 53 mg/L, total solids (TS) was 15666 mg/L, dissolved oxygen (DO) was 2.5 mgO2/L, oil and grease was 887 mg/L and chronic toxicity factor was 1667. Six possible types of filamentous fungi were isolated from the effluent sample. Among them, Epicoccum nigrum and Cladosporium sp were the most efficient in the air-lift reactor treatment. In the air-lift reactor biotreatment the fungus Epicoccum nigrum was the most efficient in the majority of the parameters reductions (of 27% COD, 62% total phenols, 94% H2O2, 44% electrical conductivity and 43% oil and grease) and Cladosporium sp was more efficient in the color reduction (87%). The oxidative treatment system (UV/H2O2) was more efficient than the biological treatment in the reductions of COD (34%) and H2O2 (98%) and increase of the DO (705%). However was less efficient in the reductions of color (74%), total phenols (24%), TS (15%) and electrical conductivity (34%) and reached a similar performance in the oil and grease reduction (45%). On the other hand, the integrated effluent treatment by UV/H2O2 system followed by biological treatment provided an intensification of reductions in all of the evaluated parameters after treatment. Indicating that the photochemistry treatment anticipated to the biological treatment increased biodegradability of the effluent sample, facilitating bioremediation in reactor air-lift. Among the three treatment systems evaluated (biological, UV/H2O2 and UV/H2O2 - biological), the integrated processes utilizing the photochemistry system UV/H2O2 followed by the biological treatment (E. nigrum) was the most efficient.

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