Thesis (doctoral)--Universität Göttingen, 2006. / Vita. Includes bibliographical references (p. 154-163).

Selon les normes actuelles, les tubes d'arme sont conçus pour résister à la pression des gaz en utilisant les équations de la statique des milieux continus. Mais lors des tirs, les chargements auquel est soumis le tube sont extrêmement rapides, de l'ordre de quelques millisecondes. En effet, le projectile est poussé à travers le tube par la pression des gaz, à ce déplacement est associé la rotation du projectile provoquée par les rayures internes du tube. Le projectile est en contact avec le tube par sa ceinture qui assure une parfaite étanchéité des gaz par son diamètre légèrement supérieur à celui du tube. Ainsi des contraintes dynamiques sont générées par la pression des gaz et par le forcement de la munition. Le but de ces travaux est d'étudier les contraintes dans le tube lors des tirs. Afin d'évaluer les différents phénomènes, dans une première partie, de nombreux essais ont été réalisés sur des armes de moyen calibre. Ces essais ont permis de constituer une base de données sur les déformations circonférentielles du tube. Dans un second temps, un modèle par éléments finis a été développé à l'aide du logiciel LS-Dyna. Le front de pression et le projectile avec sa ceinture ont été simulés. Un modèle tridimensionnel a été choisi afin d'évaluer les contraintes dans le rayage du tube, zones de concentration de contraintes. La corrélation entre les essais et les résultats de calcul est excellente. En effet le pic de déformation dynamique du tube mesuré est très bien prédit par le calcul. Pour déterminer l'influence de ce chargement dynamique, un calcul de durée de vie a été réalisé. Les résultats montrent la nécessité de prendre en compte dans le dimensionnement des tubes d'arme : la pression des gaz et l'action du projectile sur le tube. / According to current standards, gun barrels are designed to resist the maximum firing pressure using static, continuous equations. But during the firings events, complex high speed loads and structural responses arised over very short times. The projectile is pushed towards the tube by the gas pressure, morover the engraving of the tube gives a rotational movement to the ammunition. The contact between the tube and the projectile is ensured by a band or obturator. This obturator had a diameter which is superior to the tube's calibre. Very high stresses are generated during the firing, due to gas pressure and the forcing action of the projectile. The aim of this work was to study the stresses in the tube durings firings. To evaluate firings phenomena, in a first part, many tests were made on medium calibre guns using various configurations. Circumferential strain measurements were obtained. In a second time, a finite element model was developed using the commercial code LS-Dyna. The moving pressure front and the projectile with its obturator were simulated. Three dimensional modeling was chosen in order to evaluate the stresses in the tube rifling where stresses concentration were located. The numerical prediction of the peak of strain measured when the projectile passed the strain gages were excellent. Experiments and calculations showed a peak of strains which was not taken into account in tubes design. To evaluate the impact of this phenomenom, a fatigue life-time study was carried on. The results demonstrated that gas pressure and dynamic coupled actions must all be taken into account in the fatigue design of gun tubes.

Cerveja é uma bebida alcoólica mundialmente popular e a mais consumida no Brasil. Existem diversos estilos de cerveja no mundo, os quais são produzidos por modificações no processo de produção, no uso de diferentes ingredientes, na maturação utilizando barris de madeira e/ou adição de fragmentos de madeira, entre outros. A maturação em madeira pode proporcionar complexidade aromática às bebidas, sendo a madeira de carvalho amplamente utilizada para a maturação de bebidas alcoólicas. O uso dessa madeira na maturação da cerveja é o foco desse trabalho, que maturou cervejas a 0°C, durante três meses, em garrafas de vidro de 600 mL, barris de carvalho e recipientes plásticos com cubos de carvalho, na dose de 3g/L, provenientes de três níveis diferentes de tosta (leve, média, e alta). Das cervejas oriundas dos diferentes tratamentos, foram analisadas graduação alcoólica, pH, acidez total, turbidez, fenólicos totais, cor e amargor; os compostos voláteis (aldeídos, ésteres e álcoois superiores) foram analisados por Cromatografia gasosa (FID) e os compostos fenólicos de baixo peso molecular (ácido gálico, 5-hidroximetil-furfural, furfural, ácido vanílico, ácido siríngico, vanilina, siringaldeído, coniferaldeído e sinapaldeído) por Cromatografia líquida de alta eficiência (HPLC). As cervejas também foram analisadas sensorialmente mediante teste de preferência. A análise dos resultados mostrou que não houve alterações na qualidade da cerveja que pudessem ser atribuídas ao armazenamento com madeira. Os compostos voláteis tiveram pequenas alterações, por outro lado, os compostos fenólicos de baixo peso molecular foram os que apresentaram maiores incrementos no período de três meses de maturação. Não houve diferença na aceitação sensorial entre as cervejas maturadas com cubos de madeira, barril e em garrafas de vidro. Futuros estudos são necessários para que seja possível obter um produto de qualidade que possa satisfazer o consumidor e seja acessível à indústria. / Beer is a very popular alcoholic beverage in the world and the most widely consumed in Brazil. There are many styles of beer in the world that can be produced by changes in the production process, use of various ingredients, maturation using wood barrels and / or addition of wood fragments, and others. Wood maturation can provide aromatic complexity to alcoholic beverages, and the oak wood is widely used. The use of oak in the maturation of beer is the focus of this work. The beers matured at 0 °C for three months in glass bottles of 600 mL, oak barrels and plastic containers with oak cubes at a dose of 3g/L, with three different levels of toasting (light, medium, and high). Beers resulting from the different treatments were analyzed physico-chemically (alcohol content, pH, total acidity, turbidity, total phenolics, color and bitterness), the volatile compounds (aldehydes, esters and higher alcohols) by gas chromatography (FID), the low molecular weight phenolic compounds (gallic acid, 5-hydroxymethylfurfural, furfural, vanillic acid, syringic acid, vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) by High Performance Liquid Chromatography (HPLC), and sensory. The analysis shows that there were no qualities changes in beer that could be attributed to the storage in contact with oak wood. The volatile compounds had minor changes; the low molecular weight phenolic compounds were those with the greatest increases within three months of maturation. There was no difference in sensory acceptance between beers matured in oak barrel, oak cubes and glass bottles. This work suggests that wood influences sensory beer, but more studies are needed to be able to get a quality product that can satisfy the consumer and is accessible to the industry.

No description available.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-09-25T17:18:51Z No. of bitstreams: 1 HERMEVAL JALES DANTAS – TESE (PPGEP) 2013.pdf: 2896032 bytes, checksum: 137d385a4e870d4c6e3dccb8fa4f36c8 (MD5) / Made available in DSpace on 2018-09-25T17:18:51Z (GMT). No. of bitstreams: 1 HERMEVAL JALES DANTAS – TESE (PPGEP) 2013.pdf: 2896032 bytes, checksum: 137d385a4e870d4c6e3dccb8fa4f36c8 (MD5) Previous issue date: 2013-02 / Capes / O objetivo deste trabalho foi produzir aguardente bidestilada de algaroba e armazená-la em três diferentes tipos de madeiras (algarobeira, carvalho e cerejeira) com aplicação de três níveis de tosta, exercido por diferentes tempos de queima, na superfície interna de cada barrica. Determinaram-se as características físico-químicas (teor de água, proteína, açúcares redutores, açúcares não redutores e açúcares totais, minerais, carboidratos e acidez total) das vagens de algaroba in natura, após a prensagem e do caldo da algaroba na primeira e na segunda extração. Do caldo da algaroba foi selecionada uma cepa de levedura, a qual foi isolada e analisada do ponto de vista genético, por meio da metodologia de amplificação de DNA por eletroforese usando-se como iniciador (GTG)5 identificada como uma linhagem da Saccharomyces cerevisiae. Estudou-se a influência da velocidade de destilação e de aeração sobre os parâmetros físico-químicos, aplicando-se um planejamento fatorial 22 com três pontos centrais, na produção de aguardente bidestilada de algaroba Utilizaram-se barricas de algarobeira, cerejeira e carvalho, com tempos de um, dois e três minutos de queima na superfície interna da aduela. Na vagem de algaroba foram encontrados valores de açúcares totais, proteínas e minerais, de 35,9, 8,46 e 7,8% respectivamente, o que comprova seu potencial para a produção de aguardente; uma extração foi conseguida a partir da vagem hidratada, com valores de 17,92, 15,36 e 2,56% de açúcares totais, açúcares não redutores e de açúcares redutores, respectivamente. Selecionou-se uma linhagem de levedura existente no seu caldo de algaroba caracterizada como sendo Saccharomyces cerevisiae. A aguardente bidestilada de algaroba se encontra dentro dos parâmetros físico-químicos analisados e exigidos pelo M.A.P.A (Ministério da Agricultura, Pecuária e Abastecimento) exceto quanto aos congêneres de álcoois superiores de 584,50 mg.100mL-1 e soma dos componentes secundários de 627,29 mg.100mL-1. Quanto ao contaminante carbamato de etila, foram registrados níveis abaixo de 50 μg.L-1 quando se avaliou o efeito da velocidade de destilação e de 69,8 μg.L-1 quando se utilizou a aeração, sendo esses valores inferiores aos 150 μg.L-1 exigidos pela legislação. Dentre as aguardentes de algaroba submetidas a diferentes tipos de barricas estudadas (Algaroba, Carvalho e cerejeira) a de carvalho, submetida à queima da aduela por 2 minutos (c2) foi a que obteve melhor aceitação com valores de 74% para aparência, 76% para o aroma, 58% para o sabor e 64% para a impressão global / This study aimed to produce double-distilled spirits of algaroba (Prosopis juliflora (Sw.) DC.) and store it in barrels made of three different types of wood (algarobeira‟, cherry tree and oak), subjected to three burning levels, during different times, on the inner surface of each cask. Physicochemical characteristics (water, protein, reducing, non-reducing, and total sugars, minerals, carbohydrates contents and as well as the total acidity) of the pod in natura, after pressing, and of the algaroba juice, in the first and second extractions, were determined. A yeast strain of the algaroba juice was selected, isolated and genetically analyzed through the DNA amplification by electrophoresis, using (GTG)5 as a primer. The analyzed yeast was identified as a strain of Saccharomyces cerevisiae. The distillation speed and aeration influence on the physicochemical parameters of algaroba double-distilled spirit were analyzed, using a factorial design 22 with three central points. Casks of „algarobeira‟, cherry tree and oak were used, subjected to one, two and three minutes of burning on the stave inner surface. Values of total sugars, proteins, and minerals of 35.9, 8.46 and 7.8%, respectively, were found in the algaroba pod, evidencing its potential in the production of spirit. An extraction was made from the hydrated pod, obtaining values of total, non-reducing, and reducing sugars of 17,92, 15,36 and 2,56%, respectively. A yeast strain of algaroba juice was selected and characterized as Saccharomyces cerevisiae. The double-distilled spirit made from algaroba is within the physicochemical parameters analyzed and required by the MAPA (Ministry of Agriculture, Livestock, and Food Supply) except for the high congener of alcohols of 584.50 mg.100mL-1 and the sum of the secondary components of 627.29 mg.100mL-1. As for the contaminant ethyl carbamate, levels lower than 50 μg.L-1 and equal to 69,8 μg.L-1 were recorded by analyzing the effect of the distillation speed and aeration, respectively. These values are lower than 150 μg.L-1, which is required by the legislation. The algaroba spirit stored in the oak barrel, of which stave was subjected to burning for 2 minutes (c2), had the best acceptance of appearance (74%), aroma (76%), taste (58%), and overall impression (64%).

The Diploma Thesis deals with the explanation and the effective solution of the initial problems during a production line implementation of different type in the existing process. In order to make the production economical effective and correspondent with decided standards and customer requirements, the thesis is based on the identification and elimination of abnormal phenomenon by new production line implementation for bimetallic barrels.

Prenatal alcohol exposure (PAE) alters limb development that may lead to structural and functional abnormalities of the limb reported in children diagnosed with Fetal Alcohol Spectrum Disorder. To determine whether PAE alters the central representation of the forelimb we used the rodent barrel cortex as our model system where it was possible to visualize and quantitatively measure the size of the forepaw representation in the forepaw barrel subfield (FBS) in first somatosensory cortex. In the present study, we examined the effects of PAE on pattern and size of the forepaw and forepaw representation in FBS in neonatal rats at gestational day 32 that corresponds to postnatal day 9. Pregnant Sprague-Dawley rats were chronically intubated with binge doses of ethanol (6 g/kg) from gestational day 1 through gestational day 20. The offspring of the ethanol treated dams comprised the ethanol (EtOH) group. The effect of PAE on the EtOH group was compared with a nutritional-controlled pairfed (PF) group and a normal chowfed (CF) group. The ventral (glabrous) surface area of the forepaw digits, length of digit 2 through digit 5, and the corresponding glabrous forepaw digit representations in the FBS were measured and compared between treatment groups. In rats exposed to in utero alcohol, the sizes of the overall glabrous forepaw and forepaw digits were significantly reduced in EtOH pups compared to CF and PF pups; overall glabrous forepaw area was 11% smaller than CF controls. Glabrous digit lengths were also smaller in EtOH rats compared to CF controls and significantly smaller in digit 2 through digit 4. The glabrous digit representation in FBS was 18% smaller in the EtOH group when compared to the CF treatment. However, PAE did not produce malformations in the forepaw or alter the pattern of the forepaw representation in FBS; instead, PAE significantly reduced both body and brain weights compared to controls. Unexpectedly, little or no correlation was observed between the size of the glabrous forepaw compared to the size of the glabrous forepaw representation in the FBS for any of the treatment groups. The present findings of PAE-related alterations in sensory periphery and the central cortical representation may underlie deficits in sensorimotor integration reported among children with Fetal Alcohol Spectrum Disorder.

Pour mimer le repliement des structures tridimensionnelles des biomolécules, les chimistes ont développé des oligomères artificiels capables d’adopter des formes repliées et bien définie en solution : les foldamères. Néanmoins, la variété des structures secondaires isolées que l’on rencontre au sein des foldamères n’atteint pas encore celle des biomolécules. La combinaison de différentes séquences d’oligoamides aromatiques ayant des structures secondaires distinctes a permis le développement d’architectures de type « hélice-feuillet-hélice » définie dans lesquelles chaque sous-composant secondaire conserve son intégrité respective. Ces objets uniques en forme de panier possèdent une fenêtre ouverte modulable inscrite dans le squelette du foldamère par laquelle une molécule invitée peut être accueillie. Comme preuve de concept, la liaison et le relargage d’une molécule invitée à l’une de ces structures se sont révélées rapides à l’échelle de la RMN 1H. Ensuite, le développement de brins oligomériques composés de monomères codant pour de faibles rayons de courbure a permis l’obtention d’hélices doubles. Ces structures auto-assemblées de haut-poids moléculaires possèdent un diamètre de l’ordre du nanomètre. Enfin, des segments hélicoïdaux codant pour des diamètres larges ont été couplés à des pseudo-coudes artificiels dans le but d’obtenir des architectures possédant une large cavité polaire inspirés de la structure des tonneaux β. Ces approches ouvrent la voie vers la conception d’objets moléculaires toujours plus complexes au-delà la chimie des biomolécules. / To mimic the particular folding of the biomolecules’ three-dimensional structures, chemists have developed artificial oligomers that fold into a compact and well-defined structures in solution: foldamers. Nevertheless, the variety of isolated secondary structures of foldamers is not equal to those of biomolecules. The association of different sequences of aromatic oligoamide having distinct secondary structures allowed the development of well-defined helix-sheet-helix architectures in which subcomponents conserve their respective integrity. These unique basket-like objects possess an open-window within the foldamer backbone in which a molecular guest can be accommodate. As a proof of concept, guest binding to one of these structures was found to be fast on the NMR time scale. Then, the development of oligoamide aromatic strands made of monomer encoding for low curvature has allowed to obtain double helices structures. These self-assembled structures showing high molecular weights present a nanometer scale diameter. Eventually, these oligomeric strands were coupled to artificial turn units to obtain β-barrels-like architectures having a large polar cavity. These approaches open the access to the design of ever more complex molecular objects beyond the chemistry of biomolecules.

Se ha estudiado el efecto del volumen de la barrica, el tostado y origen de la madera de roble y la tonelería sobre los parámetros cromáticos, aromáticos, sensoriales y nutricionales de vinos de Monastrell, Cabernet Sauvignon y Petit Verdot elaborados en la D.O. Jumilla. Los resultados han mostrado que los parámetros de la barrica afectan más a los aromas del vino y su caracterización sensorial que a los parámetros cromáticos y nutricionales. Los vinos de Monastrell envejecidos en barricas de menores volúmenes y mayor nivel de tostado presentan una mayor concentración de compuestos aromáticos, aunque son menos preferidos sensorialmente. Para la crianza de los vinos de Cabernet Sauvignon, la preferencia sensorial se ha correspondido con vinos envejecidos en barricas de volúmenes pequeños, de roble americano y tostado M+, donde aparecen mayores concentraciones de compuestos aromáticos, no aportando la tonelería diferencias muy grandes. Resultados similares se han encontrado en los vinos de Petit Verdot / The effect of barrel volume, toast level, oak wood origin and cooperage on chromatic, aromatic, sensory and healthy properties of Monastrell, Cabernet Sauvignon and Petit Verdot wines has been studied. The results have shown that Monastrell wines aged in the smallest barrels and with the highest toast level showed the highest aromatic compound concentrations although they were sensorially less preferred. The use of small American oak barrels, with M+ toast level for Cabernet Sauvignon ageing showed wines with the higher volatile compound concentrations and the better sensory properties. Similar results were observed in Petit Verdot wines. Chromatic properties and antioxidant capacity of the wines did hardly show any correlation with the different factors studied.

The phenolic compounds (gallic acid, vanillic acid, vanillin, syringic acid, syringaldehyde, coumarin and scopoletin), antioxidant capacity, the congeners (acetaldehyde, acetone, furfural, ethyl acetate, n-propanol, isobutanol and isoamyl), contaminants (methanol, sec-butanol and n-butanol), and ethyl carbamate, was determined in cachaças during the aging process. The cachaça were aged in 20 liters barrels, made of nine different woods: jaboty, itauba, timborana, jequitiba, balsamo, courbaril, cerejeira, peroba and oak. The phenolic compounds and furfural were determined by HPLC/UV. The antioxidant capacity was determined using three different methods: the total phenolics by Foulin-Ciocalteu (FC), the inhibition of DPPH radical, and the method of antioxidant power of iron (FRAP). The congeners and contaminants were quantified using GC/MS. The ethyl carbamate was determined through a methodology that makes use of GC/MS with selected ion monitoring (SIM). The botanical origin of the wood’s barrels set phenolic profiles of the samples, which have become more complex, and the concentration of each phenolic compound and antioxidant capacity increased with the aging time. The majority of brazilian woods showed a higher phenolic content and antioxidant capacity than oak. The aged cachaça is a source of exogenous antioxidants, and gallic acid was the main phenolic compound incorporated during the aging process. The cachaça with a higher antioxidant capacity were aged in barrel of balsamo, followed by courbaril, cerejeira, timborana, peroba, jequitiba, oak, itauba and jaboty. The non-aged cachaça showed negligible antioxidant capacity. The aged cachaça in oak showed the similar antioxidant capacity of white wines and whiskeys. A concentration of ethyl acetate, higher alcohols and acetaldehyde increased dramatically with the aging time. The concentration of ethyl carbamate in cachaças remained constant in most of the samples. Through the methodology of principal component analysis (PCA) and hierarchical cluster analysis (HCA) cachaças were grouped according to similarities of their phenolic composition, antioxidant capacity and furfural, forming five groups: group 1 (CNE, itauba, jaboty and oak), group 2 (jequitiba and timborana), group 3 (balsamo and courbaril), group 4 (cerejeira) and group 5 (peroba). From analytical results of congeners in the cachaças could not distinguish them by PCA and HCA. The wood balsamo, followed by timborana, courbaril, jequitiba, oak, itauba and jaboty were the most suitable for aging because had higher antioxidant capacity, and comply with the limits prescribed by law for coumarin, congeners, contaminants and ethyl carbamate. The barrels of cerejeira and peroba were not indicated because during aging showed increased concentrations of coumarin and ethyl carbamate, respectively, with values far above those allowed by law. / Os compostos fenólicos (ácido gálico, ácido vanílico, vanilina, ácido siríngico, siringaldeído, cumarina, e escopoletina), a capacidade antioxidante, os congêneres (aldeído acético, acetona, furfuraldeído, acetato de etila, n-propanol, isobutanol, e isoamílico), os contaminantes (metanol, sec-butanol e n-butanol), e o carbamato de etila, foram determinados em cachaças durante o processo de envelhecimento. As cachaças foram envelhecidas em barris de 20 litros, confeccionados em nove diferentes madeiras: jaboty, itauba, carvalho, timborana, jequitiba, balsamo, courbaril, cerejeira, peroba e carvalho. Os compostos fenólicos e o furfuraldeído foram determinados por HPLC/UV. A capacidade antioxidante foi determinada empregando-se três métodos diferentes: os fenóis totais por Foulin-Ciocalteu (FC), a inibição ao radical DPPH!, e o método do poder antioxidante do ferro FRAP. Os congêneres (aldeído acético, acetona, acetato de etila, n-propanol, isobutanol, e isoamílico) e contaminantes (metanol, sec-butanol e n-butanol) foram quantificados empregando-se o GC/MS. O carbamato de etila foi determinado através de uma metodologia que empregou o GC/MS com monitoramento seletivo de íons (SIM). A origem botância das madeiras dos barris definiu os perfis fenólicos das cachaças, que tornaram-se mais complexos, e apresentaram aumento da concentração de cada composto fenólico e capacidade antioxidante, com o aumento do tempo de envelhecimento. A maioria das madeiras brasileiras apresentaram maior teor de compostos fenólicos e capacidade antioxidante do que o carvalho. A cachaça envelhecida é uma fonte de antioxidantes exógenos, tendo sido o ácido gálico o principal composto fenólico incorporado durante o processo de envelhecimento. As cachaças com maior capacidade antioxidante foram as envelhecidas em barril de balsamo, seguido por courbaril, cerejeira, timborana, peroba, jequitiba, carvalho, itauba e jaboty. A cachaça não envelhecida apresentou capacidade antioxidante desprezível. As cachaças envelhecidas em cerejeira, courbaril e jequitiba, apresentaram capacidade antioxidante tão alta quanto a de vinhos tintos. A cachaça envelhecida em carvalho apresentou capacidade antioxidante semelhante a de vinhos brancos e uísques. A concentração dos congêneres acetato de etila, alcoóis superiores e aldeído acético aumentou, consideravelmente, com o tempo de envelhecimento. Na maioria das cachaças a concentração do carbamato de etila manteve-se constante. Através da metodologia da análise dos componentes principais (PCA) e análise hierárquica de agrupamento (HCA) as cachaças foram agrupadas em função das similaridades da sua composição fenólica, furfuraldeído e capacidade antioxidante, formando 5 grupos: grupo 1 (CNE, itauba, jaboty e carvalho), grupo 2 (jequitiba e timborana), grupo 3 (balsamo e courbaril), grupo 4 (cerejeira) e grupo 5 (peroba). A partir dos resultados analíticos dos congêneres e contaminates das cachaças não foi possível distinguí-las através da PCA e HCA. A madeira balsamo, seguida por timborana, courbaril, jequitiba, carvalho, itauba e jaboty foram as mais indicadas para o envelhecimento porque apresentaram maior capacidade antioxidante, e se adequaram aos limites estabelecidos pela legislação para cumarina, congêneres, contaminates e carbamato de etila. Os barris de cerejeira e peroba não foram indicados porque durante o envelhecimento apresentaram aumento da concentração de cumarina e carbamato de etila, respectivamente, com valores muito acima dos permitidos pela legislação vigente.