Made available in DSpace on 2014-06-12T17:17:46Z (GMT). No. of bitstreams: 2 arquivo3494_1.pdf: 7591218 bytes, checksum: 0e52ee1997a7609344e089a0cfa282fa (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Universidade Federal de Pernambuco / Não se pode negar a influência das novas tecnologias na sociedade e a disseminação do ensino por meio da Educação à Distância - EAD, além do processo de expansão do ensino superior no Brasil e no mundo. Diante desta realidade, esta pesquisa teve por objetivo elaborar, aplicar e analisar um modelo de EAD online para o ensino de contabilidade, por meio de animação virtual, desenvolvido mediante as características do curso de Ciências Contábeis. Para isso, foi elaborado um curso piloto na modalidade de extensão e após os ajustes, o modelo foi aplicado na disciplina Contabilidade Gerencial do curso de graduação em Ciências Administrativas, com base na Teoria da Flexibilidade Cognitiva - TFC. O método aplicado se pautou na pesquisa qualitativa e na pesquisa de campo com estudos exploratório-descritivos combinados. Os resultados mostraram que: a) O perfil dos alunos é adequado para a modalidade à distância; b) A TFC mostrou-se adequada para a produção e análise de cursos à distância e c) O curso proporcionou aprendizagem na medida em que nos grupos avaliados com o conceito (C), na solução do caso da empresa Usar Cartão é a Melhor Opção UCMO e nas categorias qualitativas, obtiveram sucesso na avaliação. Concluímos que a modalidade à distância no formato aqui estudado é uma alternativa viável para a expansão do ensino superior de contabilidade

This thesis is focused on the evaluation of traditional chinese medicine (TCM) assortment of plants in the experimental garden ZF MENDELU. 51 species were evaluated by their aesthetic qualities. 43 species were used for harvesting and processing of drugs. These were described botanically and new information of the content of substances, the use and dosage of drugs were collected. The practical part of theses was scoped to the measurement of chemical substances content in plants. Total amount of flavonoids (TFC), phenols (TPC) and total antioxidant capacity (TAC) by FRAP and DPPH method has been investigated. For 13 plants was determined yield of essential oil. For species used in fresh state, concentration of vitamin C has also been determined. Some annual and perrenial species has been added to the assortment of cultivated plants. The list of plant species TCM, which are perspective for cultivation in the Czech Republic, has been also created.

Reverse Osmosis membranes have been successfully proven to remove almost 99% of chemicals dissolved in seawater. However, removal of certain trace elements, such as boron is challenging and relatively low for seawater reverse osmosis desalination plants compared to thermal desalination plants. Boron is naturally occurring and is present in seawater at an average concentration of 4.5-5 mg/L. While boron is a vital element, its toxicity has been proven on crops, animals and possibly humans. Additionally, boron should be removed to comply with the current guideline value of 0.5 mg/L, for drinking water, issued by the World Health Organization (WHO), which is barely attained by a single-pass process seawater reverse osmosis plant. Currently, multipass reverse osmosis membrane operations with pH modifications are the only valid method for boron removal. However, this is not economically efficient as it requires higher energy and chemicals consumptions. The objective of this study was to investigate boron removal by commercial TFC RO membranes in addition to custom-made KAUST-synthesized TFC membrane. Five membrane samples were examined: Toray, Sepro, Koch, and KAUST in-house synthesized membrane. Three different feed pH conditions were used: pH6, pH8, and pH10. Filtration experiments were conducted in two parts. In experiment 1, all five membranes were examined for boron rejection in a dead-end permeation system, whereas in experiment 2 the two membranes with the highest boron rejection from experiment 1 were tested in a cross-flow system. Permeate and feed samples were taken continuously and analyzed for boron concentration, rejection calculation. Membrane surfaces were characterized according to hydrophilicity, roughness and surface charge. The results showed for all the tested membranes that boron rejection increased as the feed pH increased. KAUST, defect-free TFC, showed the highest performance for boron rejection for all pH conditions, although, it shows the roughest surface. Toray membranes 80LB and 80B exhibited the second highest boron rejection and had the most negatively charged membrane surfaces. It was observed in this study that the rejection of boron by a membrane is due to size exclusion and charge repulsion mechanisms. It was concluded that, the KAUST, defect free TFC has the potential to be applicable for boron rejection in industrial application as it has better boron rejection than commercially available RO membranes.

In this research, an effort is made to analyze the costs of fare collection on heavy rail and motorbus systems in the U.S. Since existing ticketing and fare collection (TFC) systems are major elements of transit infrastructure and there are several new alternative TFC technologies available on the market, the need to evaluate the performance of existing TFC systems arises. However, very little research has been done, so far, to assess impacts of TFC technologies on capital and operating expenses in public transit. The two objectives of this research are: (1) to formulate a conceptual evaluation framework and a plan to assess the operating costs of existing TFC systems in transit and (2) to analyze the operating expenses associated with existing TFC systems on heavy rail and motorbus transit in the U.S. with the aid of the evaluation framework and plan. This research begins with a review of the current state of knowledge in the areas of transit TFC evaluation, the economics of public transit operations, and fare collection practices and technologies. It helps to determine the scope of work related to assessment of TFC operating costs on public transit and provides the basis for the development of a conceptual evaluation framework and an evaluation plan. Next, this research presents a systematic approach to define and describe alternative TFC systems and suggests that the major TFC system determinants are payment media, fare media, TFC equipment, and transit technology (mode). Following this is the development of measures of effectiveness to evaluate alternative TFC systems. These measures assess cost-effectiveness and labor-intensiveness of TFC operations. The development of TFC System Technology Index follows. This Index recognizes the fact that TFC systems may consist of different sets of TFC technologies both traditional and innovative. Finally, this research presents statistical results that support the hypothesis that TFC operating costs are related to transit demand, transit technology (mode) and TFC technologies. These results further suggest that: (1) TFC operating costs per unlinked passenger trip on heavy rail systems are higher than on motorbus systems and (2) TFC operating costs per unlinked passenger trip tend to increase as the use of non-electronic fare media increases. Actions for further research are also recommended. / Ph. D.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Wine is known for its favorable biochemical properties such as antioxidant, anticarcinogenic and anti-inflamatory properties. Many of these properties can be assigned to flavonoids and resveratrol. Wine is known to contain high amounts of interferences, such as proteins and lipids complicating analysis of flavonoids and other compounds of interest. Turbulent Flow Chromatography (TFC) on-line coupled to Liquid Chromatography Mass Spectrometry (LC-MS) was used to analyze flavonoids present in different types of wines. The TFC sample pretreatment is based on the fast removal of high molecular weight compounds and the removal of low molecular weight polar interferences. After the sample pretreatment, the TFC column is on-line coupled to LC-MS and a gradient is started to elute the trapped compounds and separate these in the LC-MS. The method proved to be fast, non-laborious, robust and sensitive. The feasibility of the method was tested on several red, white and rosé wines. Interday and intraday precision for all wines and concentrations were calculated to be < 12% and < 18%, respectively. The method proved to be linear for all investigated compounds and matrices in the range of 0.05 to 2 mg L-1 (r2 > 0.99). Moreover resveratrol showed also linearity (r2 > 0.99) in higher range (1 to 50 mg L-1). The LOD for the compounds in red wine ranged from 0.004 to 0.022 mg L-1, in white wine ranged from 0.002 to 0.021 mg L-1 and in rosé wine ranged from 0.003 to 0.034 mg L-1. Quantitation of resveratrol was possible using standard addition procedure, since resveratrol was present in the sample. Red wine showed a higher amount of resveratrol (4 mg L-1), compared to rosé and white wine which was 10-fold lower. Moreover, the different red wines contained also different amounts of resveratrol. The presented method may be an useful tool to study other analytes in difficult matrices, such as compounds of interest in food, drinks and biological samples. / O vinho é conhecido por suas propriedades bioquímicas benéficas como antioxidante, anticarcinogênico e antiinflamatório. Muitas destas propriedades podem ser atribuídas aos flavonóides e ao resveratrol. No vinho encontra-se uma grande quantidade de interferentes, como proteínas e lipídios, que dificultam a análise de flavonóides. Cromatografia de Fluxo Turbulento (TFC, do inglês Turbulent Flow Chromatography) acoplada on-line ao LC-MS foi utilizado para analisar flavonóides e resveratrol presentes em diferentes tipos de vinho. O preparo das amostras é baseado na remoção de compostos com alta massa molar de compostos de baixa massa molar utilizando TFC. Após o preparo das amostras a coluna de TFC é colocada on-line com o LC-MS e um gradiente é iniciado para realizar a eluição dos compostos retidos nos poros da fase estacionária da coluna de TFC e a separação dos mesmos nos sistema LC-MS. O procedimento provou ser rápido, não laborioso, robusto e sensível. A aplicação do método foi realizada com diferentes amostras de vinho tinto, branco e rosé. A precisão interdia e intradia para todos os vinhos e concentrações estudadas foram < 12 % e < 18%, respectivamente. O método provou ser linear para todos os compostos e matrizes estudadas no intervalo de 0,05 a 2 mg L-1 (r2 > 0,99). O resveratrol também mostrou linearidade (r2 > 0,99) quando utilizouse intervalo de concentração maior (1 a 50 mg L-1). O LOD obtido para os compostos em vinho tinto foi de 0,004 a 0,022 mg L-1, em vinho branco de 0,002 a 0,021 mg L-1 e em vinho rosé de 0,003 a 0,034 mg L-1. A quantificação do resveratrol foi possível utilizando-se curva de adição padrão. O vinho tinto apresentou maiores concentrações de resveratrol (4 mg L-1), quando comparado com os vinhos branco e rosé, que foram cerca de 12 vezes menores. Além disso as diferentes amostras de vinho tinto apresentaram diferentes concentrações de resveratrol. O procedimento desenvolvido pode ser uma poderosa ferramenta no estudo de outros analitos em matrizes complexas, como por exemplo compostos de interesse em alimentos, bebidas e amostras biológicas.

La réduction de la vulnérabilité sismique des structures existantes est un enjeu majeur. Le renforcement d'éléments par Tissus de Fibres de Carbone (TFC) offre une réponse intéressante à cette problématique. Ces travaux proposent une stratégie simplifiée de modélisation non linéaire permettant de prédire le comportement d'une structure en béton armé renforcée par TFC. Celle-ci est fondée sur l'utilisation d'éléments finis poutres multifibres ainsi que de modèles d'endommagement et de plasticité. Le confortement d'éléments en flexion et le confinement des poteaux sont étudiés. Plus spécifiquement une loi constitutive cyclique pour béton confiné est proposée. Cette loi est fondée sur deux modèles, le premier basé sur la théorie de l'endommagement et le second sur une série d'études expérimentales. Cette approche est validée à travers deux cas d'études : une pile de pont renforcée et une analyse de vulnérabilité d'un ouvrage sous sollicitations statiques (poussée progressive) et dynamiques.

La maintenance, la réparation et le renforcement de murs en maçonnerie par matériaux composites collés nécessitent le développement de méthodes et techniques d'évaluation de l'aptitude au service et de requalification tant pour leur restauration fonctionnelle que pour leur adaptation à de nouvelles contraintes (évolution du zonage sismique par exemple). Le présent travail de thèse a pour objectif de proposer un outil d'évaluation par calcul de l'état limite ultime de murs en maçonnerie, renforcés par composites collés, chargés dans leur plan.Les travaux effectués concernent la modélisation par homogénéisation de murs en maçonnerie et une campagne expérimentale de caractérisation du transfert de charge entre un renfort en tissu de fibres de carbone et un support en blocs creux de béton par le biais d'un joint de colle. Pour modéliser la résistance des murs maçonnés, nous proposons une loi élastique parfaitement plastique pour le comportement dans le plan d'une maçonnerie constituée de blocs liés par des joints de mortier. Le convexe de plasticité est obtenu par une technique d'homogénéisation périodique qui prend en compte la nature tridimensionnelle de la cellule de base. On obtient alors un convexe limité par plusieurs surfaces de charge. Un algorithme numérique original est ensuite proposé et programmé dans le logiciel aux Eléments Finis ABAQUS. Des simulations numériques utilisant le module développé sont présentées

A partir de l'observació de desenes de punts d'especial sinistralitat d'arreu de Catalunya i l'anàlisi de centenars de sinistres ocorreguts en aquests punts, va permetre arribar a sistematitzar que, segons sigui la decodificació del tram viari a partir de les senyals que arriben de l'entorn, senyals de tot tipus, l'usuari adapta el seu patró de conducció en aquell tipus de tram en funció de la seva experiència; el problema rau però, quan apareix de forma "sobtada" un factor "no previst" en aquell tipus de tram i per aquella forma "normal" de circular-hi, o, quan el tram canvia de categoria en pocs segons, i per tant, en pocs instants cal canviar i adaptar el patró de conducta a un entorn canviant, que no sempre les senyals de trànsit poden preveure, o en altres casos, aquestes senyals han perdut credibilitat i hom condueix "al marge" dels inputs oficials. L'adaptació, l'adaptació lenta o simplement, la no adaptació als canvis sobtats de l'entorn estaria en la base de la immensa majoria dels sinistres analitzats.

The unique floral biodiversity of Southern Africa would be reflected in the phenolic acid and flavonoid composition as well as the antioxidant activity of honeys from this region. In this exploratory investigation the total polyphenolic (TPC) and flavonoid (TFC) content, antioxidant activity as well as the cellular protective effects of a selection of honeys collected in this region was evaluated. Thirteen honey samples representative of the Western Cape (WCa, WCb and WCc), Eastern Cape (ECa, ECb and ECc), South East Mozambique (SEMa, SEMb and SEMc) and Agricultural: A-E (Eucalyptus) (A-E1 and A-E2), A-L (Litchi) and A-O (Orange) were collected. These samples were subjected to physicochemical analysis, the antioxidant content (TPC and TFC) and both enzymatic (catalase activity) and non-enzymatic activity, using the 2,2-diphenyl-2-picrylhydrazyl (DPPH), trolox equivalent antioxidant capacity (TEAC) and oxygen radical antioxidant capacity (ORAC) assays was determined. From the DPPH, TEAC and ORAC data the Relative Antioxidant Capacity Index (RACI) was calculated. To determine whether high antioxidant activity translates into significant cellular protection, biological and cellular assays were undertaken. Using the pBR322 plasmid assay and the erythrocyte haemolysis assay the ability of honeys to protect against 2,2’-Azobis(2-amidinopropane) dihydrochloride (AAPH) oxidative damage was evaluated. Further evaluation was undertaken in the SC-1 fibroblast cell line and the physiologically more relevant Caco-2 cell line. Toxicity and antioxidant effects were evaluated in the SC-1 cell line while antioxidant effects were only evaluated in the Caco-2 cell line. The long-term mitogenic and toxic effects were determined in the SC-1 cell line using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Neutral Red (NR) and Crystal Violet (CV) assays. Short term, total- and intracellular antioxidant effects were determined in both cell lines using the dichlorofluorescein diacetate assay (DCFH-DA) assay. For all cellular experiments honey at concentrations of 0.01% and 1% were used. The physiochemical properties of the honeys evaluated fulfilled the regulatory standards compiled in the Codex Alimentarius (CODEX STAN12-1981 revision 2001). The results were as follows: SEMb had the highest TPC (167.96 mg GAE/100g) and TFC (51.60 mg CE/100g) while A-E2 had the highest catalase (38.48 µmol H2O2/g) activity. RACI revealed that WCb had the highest antioxidant activity.SEMc showed the highest protection of plasmid DNA against oxidative-induced strand breaks while SEMa showed the highest protection of erythrocytes against AAPH-induced haemolysis. Although correlations were found between antioxidant content and antioxidant activity assays, no correlation was found these parameters and the biological assays. For the long-term cytotoxicity assay, AAPH showed significant cytoxicity at 0.78mM, 1.56mM and 0.28mM when measured using the MTT, NR and CV assays, respectively. Some honeys 4/13 and 3/13 showed a mitogenic effect at a concentration of 0.01% and 1% respectively. Toxic effects, were observed for 1/13 and 8/13 at 0.01% and 1% honey respectively. Toxicity after 72 h exposure varied from 10-30% (CV assay). The same concetrations of honey was used to determine the short-term, 2h, antioxidant effects in both the SC-1 and Caco-2 cell lines. No oxidative effect was found for all honeys at these concentrations. For the DCFH-DA assay using the SC-1 cell line at 1%, 12/13 and 7/13 honeys showed total and intracellular protection respectively. The highest extracellular protection was for SEMa (% Protection (%P) = 95) and SEMb (%P = 93). Intracellular protection was the highest for SEMc (%P = 21) and A-L (%P = 20). At 0.01%, 7/13 and 8/13 honeys exhibited total and intracellular protection, respectively. For both the highest protection was found for SEMc (%P = 43, total and %P = 30, intracellular). For the Caco-2 cell line at 1%, 11/13 and 4/13 showed total and intracellular protection, respectively. Of these the highest extracellular protection was for SEMb (% Protection (%P) = 90). Intracellular protection was the highest for ECa (%P = 28) and WCc (%P = 26). At 0.01%, 4/13 and 8/13 honeys showed total and intracellular protection respectively. The highest extracellular protection was found for SEMc (%P = 62) and intracellular protection was ECc (%P = 28). The SC-1 cell line was found to be the most sensitive to the antioxidant effects of honey compared to the Caco-2 cell line. The honeys SEMa, SEMb and SEMc showed protection against oxidative damage in both cell lines. In conclusion, the antioxidant activity of honeys from Southern Africa is of a high quality. The WC, SEM and EC honeys showed the highest antioxidant effects and could provide health benefits against diseases associated with oxidative stress as indicated by these results. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Anatomy / unrestricted

La maintenance, la réparation et le renforcement de murs en maçonnerie par matériaux composites collés nécessitent le développement de méthodes et techniques d'évaluation de l'aptitude au service et de requalification tant pour leur restauration fonctionnelle que pour leur adaptation à de nouvelles contraintes (évolution du zonage sismique par exemple). Le présent travail de thèse a pour objectif de proposer un outil d'évaluation par calcul de l'état limite ultime de murs en maçonnerie, renforcés par composites collés, chargés dans leur plan.Les travaux effectués concernent la modélisation par homogénéisation de murs en maçonnerie et une campagne expérimentale de caractérisation du transfert de charge entre un renfort en tissu de fibres de carbone et un support en blocs creux de béton par le biais d'un joint de colle. Pour modéliser la résistance des murs maçonnés, nous proposons une loi élastique parfaitement plastique pour le comportement dans le plan d'une maçonnerie constituée de blocs liés par des joints de mortier. Le convexe de plasticité est obtenu par une technique d'homogénéisation périodique qui prend en compte la nature tridimensionnelle de la cellule de base. On obtient alors un convexe limité par plusieurs surfaces de charge. Un algorithme numérique original est ensuite proposé et programmé dans le logiciel aux Eléments Finis ABAQUS. Des simulations numériques utilisant le module développé sont présentées / Maintenance, repair and reinforcing of masonry walls with composite materials glued require the development of methods and techniques for evaluating the suitability for service and retraining for both their functional restoration for their adaptation to new constraints (changes seismic zoning for example). This thesis aims to propose an evaluation tool by calculating the limit state of masonry walls,reinforced bonded composite, loaded in their plane.The work done on modeling by homogenization of masonry walls and acampaign experimental characterization of charge transfer between a reinforcement of carbon fiber fabric and a backing of hollow blocks concrete by means of an adhesive joint. To model the resistance of masonry walls, we propose a law for elastic perfectly plastic behavior in the plane formed of masonry blocks connected by mortar joints. The convex plasticity is obtained byperiodic homogenization technique which takes into account the three dimensional nature of the basic cell. This gives a convex bounded by several surfaces of charge. An algorithm digital original is then proposed and programmed in the finite element software ABAQUS. Numerical simulations using the developed module are presented