O sabugo de milho, devido a sua estrutura lignocelulósica, pode servir como fonte de biomassa renovável na produção de açúcares solúveis que podem ser convertidos em produtos de elevados valores agregados, como etanol e outros. A hidrólise ácida é o método mais utilizado na obtenção de hidrolisado hemicelulósico de materiais lignocelulósicos ricos em açúcares fermentescíveis, sendo o açúcar xilose em maior concentração. A levedura fermentadora de xilose Scheffersomyces stipitis está entre os poucos organismos que utilizam a xilose e a glicose e exibem um sistema regulatório de transição entre o processo respiratório e o fermentativo. Este trabalho teve como objetivo contribuir para o desenvolvimento de uma tecnologia de obtenção de bioetanol por S. stipitis CBS 6054, a partir da fração hemicelulósica do sabugo de milho, avaliando a formulação nutricional do meio de fermentação. Como fonte de nitrogênio alternativa foi escolhida o farelo de soja. O hidrolisado hemicelulósico de sabugo de milho (HHSM), obtido por hidrólise ácida, foi concentrado a vácuo e tratado pela elevação e abaixamento de pH. O hidrolisado de farelo de soja foi obtido por hidrólise enzimática (Alcalase, 600C, 100 rpm, 3h). Para avaliar a solubilidade do hidrolisado de farelo de soja em HHSM (pH de 4,0 a 7,0) empregou-se planejamento fatorial 22 completo com análise de superfície de resposta (RSM). A suplementação do HHSM com a proteína de farelo de soja solubilizada em associação ou não com outros nutrientes (ureia e sulfato de amônio) na obtenção de bioetanol por S. stipitis foi avaliada por meio de um planejamento fatorial 23 completo com RSM. A fermentação foi realizada em frascos de Erlenmeyer (125 mL) contendo 50 mL de meio sob agitação de 150 rpm e 30 °C. A concentração de inoculo foi de 1,5 g/L de células. Os resultados mostraram que a hidrólise ácida favoreceu a remoção da fração hemicelulósica (88,05%) com pouca alteração na celulose (10,06%) e da lignina (27,07%) com relação ao material in natura, proporcionando um hidrolisado hemicelulósico rico em xilose (28,30 g/L) com baixas concentrações de compostos fenólicos e furanos. O tratamento do HHSM reduziu seu teor proteico em relação ao hidrolisado concentrado (74,76%) e hidrolisado original (28,53%). O farelo de soja foi de boa qualidade apresentando solubilidade da proteína em KOH igual a 82,99% e índice de urease igual a 0,00. A hidrólise enzimática de farelo de soja hidrolisou 50,45% mais proteína do que a extração aquosa de proteína de farelo de soja, obtendo-se 45 g/L de proteína solubilizada. Na quantificação de proteína pelo método de Lowry foi necessário levar em consideração a presença de espécies interferentes do HHSM. A máxima solubilização da proteína de soja (9,02 g/L) em HHSM foi obtida maximizando a concentração de hidrolisado de farelo de soja (5,0 g/L). O pH, nos níveis estudados, não influenciou a solubilização da proteína de soja em HHSM. Pela RMS, o valor máximo para o fator de conversão de açúcares em etanol (0,20 g/g) pode ser alcançado empregando-se hidrolisado de farelo de soja em seu nível superior (5,0 g/L) e uréia (3 g/L) e sulfato de amônio (3,0 g/L) em seus pontos centrais. A fonte de proteína de farelo de soja solubilizada em HHSM tem potencial como fonte de nitrogênio alternativa na produção de bioetanol por Scheffersomyces stipitis. / The corn cob, due to its lignocellulosic structure, can be used as a biomass renewable source for soluble sugars can be converted into high value-added products, such as ethanol and others. Acid hydrolysis is the mostly used method to obtain hemicellulosic hydrolysate from lignocellulosic materials, leading to the obtaining of the xylose sugar at the highest concentration, from their hemicellulosic fraction. The xylose fermenting yeast Scheffersomyces stipitis is among the few organisms that utilize both xylose and glucose regulatory systems and exhibits a transition between the respiratory and fermentative processes. This work aims to contribute to the development of a technology to obtain bioethanol by Scheffersomyces stipitis CBS 6054, from the corn cob hemicellulosic fraction, evaluating the nutritional formulation of the fermentation medium. As an alternative of nitrogen source, it was chosen soybean bran. The corn cob hemicellulosic hydrolysate (HHSM) was obtained by acid hydrolysis, vacuum evaporated and treated by pH variation. Hydrolysate of soybean bran was obtained by enzymatic hydrolysis (Alcalase, 60°C, 100 rpm, 3h). The solubility evaluation of the hydrolysate of soybean bran in HHSM (pH 4.0 to 7.0) was performed by 22 full factorial design using response surface methodology (RSM). The supplementation of HHSM with solubilized soybean bran protein associated or not with other nutrients (urea and ammonium sulphate) to obtain bioethanol employed a 23 full factorial design using RSM. The fermentation was carried out in Erlenmeyer flasks (125 mL) containing 50mL of medium stirred at 150rpm and 30 °C. The inoculum concentration was 1.5 g/L of cells. The results showed that the acid hydrolysis favored removal of the hemicellulosic fraction (88.05%) with little change in cellulose (10.06%) and lignin (27.07%) compared to the in natura material, providing a hemicellulosic hydrolysate rich in xylose (28.30 g/L) with low concentrations of phenolics compounds and furans. Treatment of HHSM reduced protein content in the vaccum evaporated hydrolysate (74.76%) and original hydrolysate (28.53%). Soybean bran had good quality as shown by the protein solubility of KOH of 82.99 % and by urease index of 0.00. The soybean bran enzymatic hydrolysis produced 50.45% more protein than aqueous soybean bran protein extraction, yielding 45 g/L of solubilized protein. In the determination of protein content by the Lowry method was necessary to take into account the presence of interfering species of the HHSM. The maximum soybean bran protein solubility (9.01 g/L) was obtained maximizing the concentration of hydrolysate of soybean bran (5.0 g /L) in HHSM. In the range studied in this work, the pH did not influence the solubility of soybean bran protein in HHSM. For the response surface methodology, the maximum value for the ethanol yield (0.20 g/g.) can be achieved employing hydrolysate of soybean bran in its upper level (5.0 g/L) and urea (3 g/L) and ammonium sulfate (3 g/L) in their center points. The source of soybean bran protein solubilized in HHSM has potential as an alternative nitrogen source for bioethanol production by Scheffersomyces stipitis.

Recent failure of such companies as Enron, Worldcom and Parmala showed that there are internal reasons contributing to company’s financial distress. Financial distress is a condition when a company fails to meet its debt obligations. Board of directors is liable for long-term decisions and their ineffective work in monitoring and controlling management can influence companies’ performance. With that in mind, in this degree project, we would like to answer the following research question: “What is the relationship between characteristics of Board and probability of financial distress, measured by Altman’s Z-score models in Sweden and Denmark?”   The epistemological and ontological choices for our study were positivism and objectivism with deductive approach. We have calculated Z-scores of Swedish and Danish companies in order to detect distressed and healthy companies. Further on, the information about board composition in each company was collected; mainly we were interested in board independence, board size, board ownership, COB ownership, CEO duality and employee representatives.   In order to examine if there is a relationship between board composition and financial distress, we have done Multiple and Binary Regression analyses. Based on the results we can state that board independence, board ownership and employee representatives and market capitalization (control variable) have significant relationship with probability of financial distress. Our study is interesting since we have looked at employee representatives, as a board characterectic that is specific for Nordic countries and that was not studied before. In addition, we have found that there is no CEO duality in Sweden and Denmark, since all companies in our sample followed the Companies’ Acts. COB ownership, the additional variable we wanted to test and board size have shown no significant relationship.

L'utilisation de matériaux locaux, naturels et non transformés offre des solutions prometteuses de construction à faible impact environnemental. La grande variabilité spatiale de ces matériaux est cependant un obstacle à une utilisation à plus grande échelle. Les stratégies de construction développées par les anciens bâtisseurs ont été dictées par le climat local et la qualité ainsi que la quantité de matériaux de construction disponibles localement. Ces stratégies de construction peuvent être considérées comme une gestion optimisée des ressources locales, naturelles et variables et sont une source d'inspiration pour la construction durable moderne. Malheureusement, cette connaissance a été perdue dans les pays occidentaux au cours du 20ème siècle. La redécouverte des savoir-faire traditionnels requiert le développement de moyens rationnels d’analyse du patrimoine. Un autre problème concernant l'utilisation de matériaux de construction naturels et variables est leur conformité vis-à-vis de la réglementation du secteur du bâtiment. Le développement de procédures d’essais performantiels est proposé comme solution pour faciliter l'utilisation des techniques de construction en terre. Une approche multidisciplinaire est proposée, combinant micromorphologie, pédologie, géotechnique et étude du patrimoine pour analyser le bâti vernaculaire en terre. Cette approche fournit des outils complémentaires pour évaluer la source des matériaux de construction et identifier les caractéristiques géotechniques de la terre employées dans le patrimoine. Il fournit également une description détaillée des processus vernaculaires de construction. En utilisant ces résultats, il a été possible d'élaborer des cartes de ressources et d’estimer l’ordre de grandeur de la disponibilité des ressources à l'échelle d’une région. Deux procédures d’essais performantiels ont été proposées afin de tenir compte de la variabilité naturelle des terres dans le contexte réglementaire actuel. La construction en terre jouera un rôle important dans la construction durable du 21ème siècle si les acteurs du secteur adoptent des procédés de construction capables de répondre à la demande sociale, avec un faible impact environnemental et à un coût abordable. L'étude du patrimoine en terre a démontré la capacité des anciens bâtisseurs à innover afin de se conformer aux variations de la demande sociale et aux développements techniques. La construction en terre bénéficie d'un passé ancien et riche et il convient de tirer profit de ce retour d’expérience. L'analyse du patrimoine en terre et la redécouverte des techniques de construction vernaculaire est une source d'inspiration précieuse pour la construction contemporaine. La valorisation des connaissances vernaculaires permettra d’économiser du temps, de l'énergie et d'éviter de répéter les erreurs passées. L'avenir de la construction de la terre doit s’inscrire dans la continuité de la construction en terre vernaculaire. / The use of local, natural and unprocessed materials offers promising low impact building solutions. The wide spatial variability of these materials is, however, an obstacle to a large-scale use. The construction strategies developed by past builders were dictated by the local climate and the quality and the amount of locally available construction materials. These construction strategies can be regarded as an optimized management of local, natural and variable resources and are a source of inspiration for modern sustainable building. Unfortunately, this knowledge was lost in Western countries during the 20th century. Vernacular earth construction know-how rediscovering requires the development of rational built heritage investigation means. Another issue regarding the use of natural and variable building material is their compliance with modern building regulation. The development of performance based testing procedures is proposed as a solution to facilitate the use of earth as a building material. A multidisciplinary approach is proposed, combining micromorphology, pedology, geotechnics and heritage disciplines to study vernacular earth heritage. It provides complementary tools to assess pedological sources of construction material and geotechnical characteristics of earth employed in vernacular earth heritage. It also provides a detailed description of the construction process of vernacular earth heritage. Using these results, it was possible to draw resource maps and provide a scale of magnitude of resource availability at regional scale. Two performance based testing procedures were proposed in order to take into account the natural variability of earth in a modern building context. Earth construction will play an important role in the modern sustainable building of the 21st century if the actors of the sector adopt earth construction processes able to meet social demand, with low environmental impact and at an affordable cost. The study of earth heritage demonstrated the ability of historical earth builders to innovate in order to comply with social demand variations and technical developments. Earth construction benefits of an old and rich past and it would be a non-sense to leave this past behind. The analysis of earth heritage and the rediscovering of vernacular construction techniques is a valuable source of inspiration for modern earth construction. The valorisation of vernacular knowledge will save time, energy and avoid repeating past mistakes. The future of earth construction should be a continuation of past vernacular earth construction.

<p>U okviru istraživačkog rada formiran je matematički model za simulaciju<br />procesa transformacije energije u postrojenju gasne turbine pri<br />sagorevanju gasova srednje ili niže toplotne moći. Data je analiza procesa<br />kosagorevanja gasa iz gasifikacije kukuruznog oklaska i prirodnog gasa u<br />postrojenju gasne turbine, za tri različite konfiguracije postrojenja.<br />Analiza je rađena na primeru osnovnog Joule-ovog ciklusa sa vazduhom<br />hlađenim lopaticama.</p> / <p>This paper presents mathematical model for simulation of energy<br />transformation process in gas turbine facility with combustion of medium<br />and low calorific gases. The basis of the mathematical model is the<br />M&uuml;ller&rsquo;s method. Analysis of co-firing the corn cob gas and natural gas for<br />different gas turbine facility configurations is presented. The basic Joule<br />cycle with blade cooling was analyzed.</p>

La terre est le premier matériau de construction par les hommes, disponible et peu consommateur d’énergie. Aujourd’hui encore, environ 30 % des habitants de la planète vit dans des habitats en terre, et pour les pays en développement, ce pourcentage s’élève à 50 % de la population rurale. De plus, les matériaux à base de terre permettent un meilleur équilibre et contrôle du climat thermique et acoustique intérieur par rapport aux matériaux usuels de construction. Cependant, la majorité des constructions en terre ne répondent pas aux exigences actuelles en termes de contraintes mécaniques, thermiques ou architecturales. Afin de répondre à ces exigences, un travail tant au niveau scientifique qu’au niveau des praticiens est à accomplir dans ce domaine.L’objectif de cette étude est de déterminer l’influence des propriétés des matériaux utilisés sur le comportement mécanique et hygrothermique de composites terre-fibres végétales. Pour cela, différents types de sols et de fibre végétales (paille de lin, paille de blé) ont été utilisés. Ensuite, les performances mécaniques (compression, flexion) et hygrothermiques (sorption/désorption, perméabilité à la vapeur d’eau, conductivité thermique) ont été déterminées pour différents composites terre-fibres végétales. Les résultats montrent que l’utilisation de paille de lin permet d’obtenir des performances mécaniques supérieures à celles obtenues pour la paille de blé. Cependant, il est à noter que l’introduction de fibres aux sols diminue les performances mécaniques due à la diminution de la densité du matériau. Aucune influence claire de la longueur des fibres sur les performances mécanique n’a été constatée. L’étude du comportement hygrothermique a permis de montrer que le comportement à la sorption/désorption du matériau terre-fibres végétales peut être approximer à partir des résultats obtenus pour les matériaux de base. De plus, il a été démontré que l’évolution de la conductivité thermique du matériau terre-fibres végétales au cours du séchage est reliée au comportement au retrait. / Soil is the first construction material used by man, widely available and low energy consuming. Indeed, about 30% of the current world population lives in earthen structures and, in developing countries, this rate rise to 50%, mostly rural. Moreover, earth-based materials allow an improved balance and control of thermal and acoustic indoor climate compared to industrial construction materials. However, most of earthen structures do not reach current requirements in terms of mechanical, thermal or architectural. To respond to these requirements, a work at scientific and craftsman levels is necessary.The objective of this study is to determine the influence of materials’ properties on the mechanical and hygrothermal behaviour of earth-fiber composites. In order to do this, different types of soil and plant fiber (flax straw, wheat straw) were used. Then, mechanical (compression, bending) and hygrothermal performances (sorption / desorption, water vapor permeability, thermal conductivity) were determined for different soil-fiber composites. Results show that the use of flax straw provides better mechanical performances than use of wheat straw. However, it should be noted that fibers addition to soil decreases mechanical performance due to the decrease of material density. No clear influence of fiber length on mechanical performance was found. The study of hygrothermal behaviour has shown that the sorption / desorption behaviour of earth-fiber material can be approximated from the results obtained from basic materials. In addition, it has been shown that the thermal conductivity evolution of earth-fiber material during drying is related to the shrinkage behaviour.

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Made available in DSpace on 2014-12-17T14:03:32Z (GMT). No. of bitstreams: 1 RaniereFMS.pdf: 3115798 bytes, checksum: 664aaedacd292e8b8c2d08a15e193378 (MD5) Previous issue date: 2010-02-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The corn cob is an agricultural by-product still little used, this in part due to the low knowledge of the biotechnological potential of their molecules. Xylan from corn cobs (XSM) is a polysaccharide present in greater quantity in the structure of plant and its biotechnology potential is little known. This study aimed to the extraction, chemical characterization and evaluation of biological activities of xylan from corn cobs. To this end, corncobs were cleaned, cut, dried and crushed, resulting in flour. This was subjected to a methodology that combines the use of alkaline conditions with waves of ultrasound. After methanol precipitation, centrifugation and drying was obtained a yield of 40% (g/g flour). Chemical analysis indicated a high percentage of polysaccharides in the sample (60%) and low contamination by protein (0.4%) and phenolic compounds (> 0.01%). Analysis of monosaccharide composition indicated the presence of xylose:glucose:arabinose:galactose:mannose:glucuronic acid in a molar ratio 50:20:15:10:2.5:2.5. The presence of xylan in the sample was confirmed by nuclear magnetic resonance (?H and ??C) and infrared spectroscopy (IR). Tests were conducted to evaluate the antioxidant potential of XSM. This showed a total antioxidant capacity of 48.45 EAA/g sample. However, did not show scavenging activity of superoxide and hydroxyl radical and also reducing power. But, showing a high capacity chelating iron ions with 70% with about 2 mg/mL. The ability to XSM to influence cell proliferation in culture was also evaluated. This polymer did not influence the proliferation of normal fibroblast cells (3T3), however, decreased the rate of proliferation of tumor cells (HeLa) in a dose-dependent, reaching an inhibition of about 50% with a concentration around 2 mg/mL. Analyzing proteins related to cell death, by immunoblotting, XSM increases the amount of Bax, Bcl-2 decrease, increase cytochrome c and AIF, and reduce pro-caspase-3, indicating the induction of cell death induced apoptosis dependent and independent of caspase. XSM did not show anticoagulant activity in the PT test. However, the test of activated partial thromboplastin time (aPTT), XSM increased clotting time at about 5 times with 600 ?g of sample compared with the negative control. The presence of sulfate on the XSM was discarded by agarose gel electrophoresis and IR. After carboxyl-reduction of XSM the anticoagulant activity decreased dramatically. The data of this study demonstrate that XSM has potential as antioxidant, antiproliferative and anticoagulant compound. Future studies to characterize these activities of XSM will help to increase knowledge about this molecule extracted from corn and allow their use in functional foods, pharmaceuticals and chemical industries. / O sabugo de milho ? um subproduto agr?cola ainda pouco utilizado, isto se deve em parte ao baixo conhecimento do potencial biotecnol?gico de suas biomol?culas. Xilana de sabugo de milho (XSM) ? um polissacar?deo presente em maior quantidade na estrutura do vegetal e seu potencial biotecnol?gico ? pouco conhecido. Este trabalho teve como objetivo a extra??o, caracteriza??o qu?mica e avalia??o de atividades biol?gicas de XSM. Sabugos de milho foram limpos, cortados, desidratados e triturados, dando origem a uma farinha. Esta foi submetida a uma metodologia que combina o uso de meio alcalino com ondas de ultra-som. Ap?s precipita??o metan?lica, centrifuga??o e secagem obteve-se um rendimento de 40% (g/g de farinha). An?lises qu?micas indicaram um alto percentual de polissacar?deos na amostra (60%) e baixa contamina??o por prote?nas (0.4%) e compostos fen?licos (>0.01%). An?lises da composi??o monossacar?dica por cromatografia em papel e por cromatografia l?quida de alta performance (CLAE) indicaram a presen?a de xilose:glicose:arabinose:galactose:manose:?cido glucur?nico em uma propor??o molar de 50:20:15:10:2,5:2,5. A presen?a de xilana na amostra foi confirmada por resson?ncia magn?tica nuclear (13C e 1H) e por espectroscopia de infravermelho (IR). Testes foram realizados para avalia??o do potencial antioxidante de XSM. Esta mostrou uma capacidade antioxidante total de 48.45 EAA/g de amostra. Contudo, a mesma n?o mostrou atividade sequestradora de super?xido, radical hidroxila bem como poder redutor. Em contra partida, apresentou 70% de atividade quelante de ?ons de ferro na concentra??o de 2 mg/mL. A capacidade de XSM em influenciar a prolifera??o celular em cultura tamb?m foi avaliada. Este polissacar?deo n?o influenciou a prolifera??o de c?lulas fibrobl?sticas normais (3T3), entretanto, diminuiu a taxa de prolifera??o de c?lulas tumorais (HeLa) de maneira dose-dependente, chegando a uma inibi??o de aproximadamente 50% com concentra??o em torno de 2 mg/mL. Analisando prote?nas relacionadas ? morte celular, atrav?s de immunoblotting, XSM aumenta a quantidade de Bax, citocromo c e AIF e diminui Bcl-2 e procaspase- 3, indicando a indu??o de morte celular por apoptose dependente e independente de caspase. XSM n?o apresentou atividade anticoagulante pelo teste de PT. Todavia, no teste de tempo de tromboplastina parcial ativada (aPTT), XSM aumentou o tempo de coagula??o em cerca de 5 vezes utilizando 600 ?g de amostra, quando comparadas com o controle negativo. A presen?a de sulfato ligado a XSM foi descartada por eletroforese em gel de agarose e por IR. Ap?s carboxirredu??o de XSM a atividade anticoagulante diminuiu drasticamente. Os dados deste trabalho demonstram que XSM apresenta potencial como composto antioxidante, antiproliferativo e anticoagulante. Estudos futuros de caracteriza??o dessas atividades do XSM contribuir?o para aumentar o conhecimento sobre esta mol?cula extra?da de milho e permitir?o a sua utiliza??o em alimentos funcionais, produtos farmac?uticos e ind?strias qu?micas.

Cette thèse analyse la surmortalité par suicide sur le territoire du Pays COB au travers des facteurs psychosociaux et psychopathologiques et repose sur l'hypothèse d'interactions entre les conceptions sociales du suicide et les trajectoires personnelles des individus, freinant sa prévention. Une étude des représentations sociales du suicide montre qu’il existe des RS spécifiques en Bretagne et en Pays COB. L’étude des trajectoires de vie met en évidence une sur-représentation de la dépression et les troubles de la personnalité. On trouve aussi une faible estime de soi, une difficulté d'accès à la parole et à la demande d’aide, des violences transgénérationnelles et actuelles, un climat incestuel et une stigmatisation (auto et hétéro) liée aux RS du suicide, de la dépression et des « psy ». L’étude de l’effet d’un suicide montre qu’il a un impact sur les proches : traumatisme psychique individuel et familial, deuils traumatogènes. À la suite de ces résultats, des actions spécifiques pourront être menées sur ce territoire pour améliorer la prévention du suicide et des tentatives de suicide. / The present thesis analyzes the role of psychosocial and psychopathological factors in the abnormally high rate of deaths by suicide in the “Pays COB” territory. It is based on the hypothesis according to which the interactions between the social conceptions of suicide and the personal trajectories hinders suicide prevention. We studied the structure of social representations of suicide (SR) with Vergès’method (double analysis of the evocation rank) and uncover specific SR in Brittany and in “Pays COB”. A study of the life trajectories highlighted the excessive rate of depressions and personality disorders. We also found amoung suicide victims a weak self-esteem, a difficulty to talk and to ask for help, transgenerational and current violent tendencies, an incestual climate and (self-) stigmatization related to the SR of suicide, depression and psychiatric services. A study about the effect of a suicide showed that it has an impact on the close relatives: individual and family psychic trauma, traumatic grief. Following these results, specific actions can be carried out in this territory to improve the prevention of suicide and of suicide attempts.

The study examined the properties of stalk and cob fibres from recombinant inbred corn lines and their parents, grown at two locations, in a polylactic acid (PLA) matrix. The objectives were to: determine fibre compositions; evaluate the effects of fibres on the functional properties of biocomposites and identify quantitative trait loci (QTLs) and gene markers for fibre performance in biocomposites. Significant Genotype*Location effects were observed. Composites had lower strength (impact, tensile, and flexural) but higher tensile/flexural modulus values than pure PLA. The latter were positively affected by cellulose and hemicellulose but negatively affected by free phenolic levels and 93 fibre QTLs and 62 composite markers were detected. This study identified fibre traits and markers for genes that may be important for the use of corn fibres in biocomposites. / Ontario BioCar Initiative Project funded by Ontario Ministry of Research and Innovation, Agriculture and Agri-Food Canada, The Natural Sciences and Engineering Research Council, The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and Ontario Public Sector