1000 resultados para Modelos de separação de efeitos
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Simulaes de sais de carbonato fundidos pelo mtodo de Dinmica Molecular (MD) foram efetuadas com o modelo polarizvel de cargas flutuantes (FC). O modelo de cargas flutuantes implementa os efeitos de polarizao pelo mtodo de Lagrangiano estendido, onde as variveis extras so as prprias cargas parciais do on poliatmico. O modelo FC foi parametrizado por meio de clculos ab inito, aplicado ao nion carbonato. Clculos de Qumica Quntica ab initio foram utilizados para corroborar o modelo proposto para o nion carbonato. Os sistemas investigados consistem em misturas de carbonatos alcalinos fundidos, Li2CO3/K2CO3, os quais so utilizados como eletrlitos em clulas a combustvel. As simulaes MD foram utilizadas para verificar o efeito da polarizao dos nions sobre a estrutura e dinmica do lquido. Estudamos o efeito da incluso de polarizao sobre a condutividade do eletrlito.
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INTRODUO: O transplante heptico o nico tratamento efetivo para uma variedade de doenas hepticas irreversveis. No entanto, o nmero limitado de doadores peditricos leva ao uso de enxertos hepticos de doadores adultos, com necessidade de anastomoses vasculares mais complexas. Essas anastomoses tornam-se complicadas pela diferena no calibre dos vasos entre o doador e o receptor, resultando em alteraes do fluxo sanguneo, estenose da anastomose venosa ou arterial e trombose. Os efeitos para regenerao heptica decorrentes da privao do fluxo sanguneo pela veia porta ou pela artria heptica no esto completamente elucidados. Experimentalmente, quando um lobo do fgado no recebe o fluxo venoso portal, observada atrofia deste segmento e hipertrofia do restante do rgo perfundido. Embora existam vrios modelos experimentais para estudo da regenerao heptica, poucos so focados em animais em crescimento. Alm disso, os efeitos regenerativos de drogas como o tacrolimus e a insulina precisam ser pesquisados, com o objetivo de encontrar um tratamento ideal para a insuficincia heptica ou um mtodo de estimular a regenerao do fgado aps resseces ou transplantes parciais. O objetivo do presente estudo descrever modelos de regenerao heptica em ratos em crescimento com: 1) ausncia de fluxo heptico arterial e 2) reduo do fluxo portal. Adicionalmente, o estudo avalia o efeito pr-regenerativo do tacrolimus e da insulina nesses modelos descritos. MTODOS: cento e vinte ratos (entre 50 e 100g de peso) foram divididos em 6 grupos, de acordo com o tipo de interveno cirrgica: Grupo 1, inciso abdominal sem interveno heptica; Grupo 2, hepatectomia a 70%; Grupo 3, hepatectomia a 70% + estenose de veia porta; Grupo 4, hepatectomia a 70% + ligadura da artria heptica; Grupo 5, hepatectomia a 70% + estenose de veia porta + insulina; Grupo 6, hepatectomia a 70% + estenose de veia porta + tacrolimus. Os animais dos grupos 1 ao 4 foram subdivididos em 5 subgrupos de acordo com o momento da morte: 1, 2, 3, 5 e 10 dias aps a interveno cirrgica. Os animais dos grupos 5 e 6 foram subdividos em 2 subgrupos de acordo com o momento da morte: 2 e 10 dias aps a interveno cirrgica. Os lobos hepticos remanescentes foram submetidos anlise histomorfomtrica, imuno-histoqumica e molecular. RESULTADOS: Verificou-se que no grupo com hepatectomia a 70% houve recuperao do peso do fgado no terceiro dia com aumento da atividade mittica, enquanto que no grupo com estenose portal no se observou esse fenmeno (p < 0,001). A insulina e o tacrolimus promoveram aumento do peso do fgado e do ndice mittico. A atividade mittica foi considerada aumentada nos animais dos grupos hepatectomia, hepatectomia + ligadura da artria, insulina e tacrolimus; e esse parmetro estava reduzido no grupo submetido hepatectomia + estenose portal (p < 0,001). A expresso de interleucina 6 estava presente em todos os animais, sendo significativamente maior nos grupos hepatectomia, hepatectomia + ligadura da artria e significativamente menor no grupo hepatectomia + estenose portal. Entretanto, a administrao de tacrolimus ou insulina recuperou os nveis teciduais de interleucina 6 no grupo com estenose portal. CONCLUSES: No presente estudo foi padronizado um modelo simples e facilmente reprodutvel para estudar a regenerao heptica em ratos em crescimento com reduo do fluxo arterial ou venoso para o fgado. Foi demonstrado que a administrao de insulina ou tacrolimus capaz de reverter os efeitos deletrios da estenose portal na regenerao heptica. A obstruo do fluxo arterial no afetou a capacidade regenerativa heptica
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O lobo-guar uma espcie de ampla distribuio na Amrica do Sul, tendo no Brasil sua maior rea de ocorrncia. No entanto, as modificaes das reas naturais principalmente destinadas agropecuria tornam a espcie vulnervel extino. A investigao objetivou conhecer em larga escala a rea de distribuio potencial gerada por atributos ambientais favorveis e reas adequadas sua ocorrncia nos biomas brasileiros e investigar como a espcie responde estrutura da paisagem, avaliando os efeitos de ambientes modificados pelo homem na sua ecologia espacial, nos padres de atividade e na movimentao. Modelos de distribuio de espcie foram gerados pelo Maxent, utilizando uma base de pontos de localizao de presena a partir de 2000 para o Cerrado (Ce), Pantanal (Pa), Mata Atlntica (MA) e Pampas (Pp) e um conjunto de onze variveis ambientais no correlacionadas (topogrficas, climticas e paisagsticas). Para anlises de ecologia espacial, das atividades e de movimentao, utilizou-se localizaes de telemetria (GPS) de animais habitantes de reas protegidas (AP), e indivduos em paisagens modificados (AM). Anlises de reas de vida (AV) foram realizadas utilizando o estimador AKDE e associadas com classificao da paisagem local. Os modelos de distribuio do lobo-guar apresentaram uma rea de distribuio potencial de 78% do total dos biomas. Apesar de possurem grandes propores de reas adequadas (Ce, 90%; Pa, 93%; MA, 65% e Pp, 6%), somente um pequeno percentual (4,4% do Ce e 4,7% da MA) possui adequabilidade ambiental acima de 50%. Dos atributos que favorecem sua presena, a altitude (para todos os biomas), a precipitao (Ce e Pa), diferenas de temperatura e uso e cobertura do solo (Ma e Pp) foram os mais importantes. Em nvel local, animais apresentaram mdia de AV de 90Km2 em AP e 41Km2 em AM, uma diferena significativa (p<0,01) com reas diretamente proporcionais ao percentual de reas naturais na paisagem. Ainda, apesar dos padres regulares de atividade no mostrarem grandes mudanas, o perodo de repouso foi significativamente maior (p<0,01) entre os animais AM (46% do dia) que em animais AP (25% do dia). Lobos-guars de AP e AM no apresentaram grandes diferenas no deslocamento dirio com mdia geral de 14km caminhados por dia, com comprimentos de passos de 1Km. Diferenas no comprimento de passo foram relacionadas composio da diversidade de contato de classes da paisagem com a proporo de ambientes naturais no passo (quanto maior as variveis, maior o passo). Passos menores refletem menor persistncia de movimento interferindo no deslocamento dirio. Com os resultados desse estudo identificou-se a MA e Pa muito importantes, mas o Ce como bioma mais adequado espcie. Foram encontrados indcios de que a estrutura de suas AV, o uso da paisagem, as atividades e movimentao so afetados pela paisagem modificada. Isso pode comprometer a viabilidade populacional, interferindo na presena em uma rea e refletindo no seu potencial de distribuio. As estratgias de manejo de uso do solo, e a recuperao e conexo de reas adequadas so urgentes e necessrias para que o lobo-guar permanea presente e funcional nas paisagens dos biomas brasileiros.
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Alteraes nos regulamentos, mudanas no comportamento do consumidor e potenciais ganhos de competitividade so alguns dos motivos citados por gestores como motivadores para a adoo de vrias prticas de gesto ambiental. Estas prticas afetam, de acordo com outros estudos, os desempenhos ambiental e financeiro das empresas. No entanto, prticas diferentes afetam de forma diferente os desempenhos mencionados, ou ainda algumas prticas podem ser usadas de forma propagandsticas, podendo afetar o desempenho financeiro, mas no necessariamente o desempenho ambiental.. Assim, este trabalho tem como objetivo verificar se h relao entre as prticas de gesto ambiental (aqui divididas em \'prticas de planejamento e organizao\', \'prticas operacionais\' e \'prticas comunicacionais\') utilizadas pelas empresas e os desempenhos ambiental e financeiro destas por meio da anlise de empresas do setor qumico brasileiro, utilizando modelagem de equaes estruturais (Structural Equation Modeling - SEM) e uma survey para coleta dos dados subjetivoprimrios (percepo dos gestores). Para tanto, foi desenvolvido um modelo terico e construdo um diagrama de caminhos de relaes causais que foi convertido em um conjunto de modelos estruturais e de mensurao. Para testar o modelo proposto, um teste emprico foi aplicado em empresas do setor qumico brasileiro. Os resultados deste teste foram os seguintes: (a) PGAs de planejamento e organizao possuem uma relao positiva com o desempenho ambiental e o com desempenho financeiro; (b) PGAs operacionais possuem uma relao negativa com o desempenho financeiro; (c) PGAs comunicacionais possuem uma relao positiva com o desempenho financeiro; (d) No h relao estatisticamente significativa entre as PGAs operacionais e o desempenho ambiental; (e) No h relao estatisticamente significativa entre as PGAs comunicacionais e o desempenho ambiental; (f) No h relao estatisticamente significativa entre o desempenho ambiental e o desempenho financeiro. Neste estudo, as prticas de gesto ambiental se relacionam mais significativamente com o desempenho financeiro, podendo indicar, na amostra estudada, um perfil menos proativo de gesto ambiental, com foco na adequao legar para a continuar com um bom desempenho financeiro.
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Dissertao, Mestrado, Contabilidade e Fiscalidade, Instituto Politcnico de Santarm, Escola Superior de Gesto e Tecnologia, 2016
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No campo da estratgia, a inovao reconhecida como uma possvel fonte de vantagem competitiva a mdio e longo prazo. No Brasil, onde aes visando a melhoria de competitividade internacional tem sido empreendidas, a inovao torno-se um assunto de grande interesse entre aqueles que buscam uma melhoria no desempenho de seus produtos e processos, alm da conquista de novos mercados. No temos conhecimento, no entanto, de trabalhos que analisem os resultados efetivos de inovao da cooperao e do acesso a fontes de informao. Assim, este trabalho visa contribuir com a anlise do impacto percebido pelos gestores com relao aos efeitos da cooperao e das fontes de informao sobre a inovao em produtos, processos e mercado, considerando as empresas com sede no Estado de So Paulo. Utilizou-se a base de dados da PINTEC - Pesquisa de Inovao Tecnolgica, publicada pelo IBGE Instituto Brasileiro de Geografia e Estatstica, referente ao trinio 2006-2008. Foram estimados 32 modelos de regresso categrica mltipla, a fim de averiguar o quanto as variveis cooperao e fontes de informao explicam o impacto percebido em produtos, processos e mercado. Nos resultados das regresses para 1413 empresas que apresentaram uma alta cooperao com universidades ou institutos de pesquisa foi possvel observar um impacto altamente significante no aumento da capacidade de produo ou de prestao de servios e significante na abertura de novos mercados. Para todas as variveis dependentes do estudo, indicadoras de inovao em produto, processo e mercado foram observados efeitos altamente significantes sobre as variveis dependentes de impacto inovativo quando consideradas as variveis independentes indicadoras de fontes de informao com clientes, consumidores e fornecedores, em quaisquer nveis de intensidade (alto, mdio e baixo) atribudos pelo respondente. J o acesso a fontes de informao advindo das universidades e instituies de ensino superior mostrou-se significante para as seguintes variveis dependentes de resultados de inovao a) melhoria na qualidade dos bens ou servios, b) na ampliao da gama de bens ou servios ofertados, c) na reduo dos custos de produo ou dos servios prestados e d) na abertura de novos mercados. Entre as principais contribuies acadmicas deste trabalho esto o melhor entendimento sobre a percepo dos efeitos em inovao e suas origens sob a perspectiva do gestor. Espera-se que os resultados desse trabalho possam embasar decises de gestores e formadores de polticas de inovao.
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Este estudo avaliou as alteraes produzidas nos arcos dentais superiores de pacientes submetidos Expanso Rpida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com mdia de idade de 23,3 anos. Para cada paciente foram preparados trs modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatrio (T1); trs meses ps-expanso (travamento do expansor) e momento da remoo do aparelho expansor tipo Hyrax e colocao da placa removvel de acrlico para conteno (T2); seis meses ps-expanso e momento de remoo da placa de acrlico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lmina pterigide, osteotomia da espinha nasal linha mdia dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O incio da ativao ocorreu no terceiro dia ps-operatrio, sendo de volta pela manh e noite, sendo que as ativaes seguiram critrios clnicos para o controle da expanso. As medidas foram realizadas por meio da mquina de medio tridimensional (SAC), baseando-se nas alteraes nos trs planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distncias transversais em todos os grupos de dentes (de incisivos centrais at segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 no houve diferena estatisticamente significante para nenhuma varivel, indicando, assim, estabilidade aps seis meses do trmino da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinaes dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pr-molares apenas do lado esquerdo, sugerindo um comportamento assimtrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenas estatisticamente significantes entre T1 x T2 e T1 x T3; 4. No foram observadas diferenas estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)
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A distalizao dos molares superiores uma opo de tratamento da m ocluso de Classe II, quando o envolvimento principalmente dentoalveolar. Dispositivos intrabucais como o aparelho Pndulo, dispensam a colaborao do paciente quanto ao uso, porm promovem efeitos muitas vezes indesejveis como a vestibularizao dos dentes anteriores que participam na ancoragem e a inclinao dos molares distalizados. Aps o surgimento dos Dispositivos de Ancoragem Temporria (DATs), como o mini-implante pode-se alcanar a ancoragem de forma previsvel e eficiente. Com isto, por meio de um estudo prospectivo, foram avaliadas as alteraes dentrias, promovidas pela distalizao de molares superiores com um aparelho Pndulo modificado, apoiado em dois mini-implantes instalados no palato de 10 indivduos, sendo 2 do sexo feminino e 8 do masculino, com mdia de idade de 14,3 anos. A amostra foi composta por 20 modelos digitalizados em 3D, obtidos de em duas fases: no incio do tratamento (T1) e aps distalizao com sobrecorreo de 1 mm (T2), permitindo quantificar as alteraes dentrias sagitais, transversais e possveis movimentos de rotao, angulao e movimentos verticais. Os resultados obtidos mostraram que no sentido sagital, houve uma efetiva distalizao com significncia estatstica, para os segundos molares superiores; primeiros molares superiores em mdia de 4,34 mm e 3,91mm para o lado direito e esquerdo, respectivamente, e para os segundos pr-molares do lado direito e esquerdo de 2,06 mm e 1,95 mm, respectivamente. Porm, para os dentes anteriores, foi constatada a perda de ancoragem. No sentido transversal, o maior aumento ocorreu na regio dos dentes posteriores. Os movimentos de rotao, angulao e vertical dos primeiros molares superiores, indicam que houve rotao mesiovestibular e inclinao distal das coroas destes dentes de ambos os lados; as medidas verticais, demonstram que houve movimento significativo apenas para o primeiro molar direito, com inclinao distal pela intruso da cspide distal. Este dispositivo mostrou-se eficaz na correo da Classe II em um tempo mdio de 6,2 meses.(AU)
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The principal effluent in the oil industry is the produced water, which is commonly associated to the produced oil. It presents a pronounced volume of production and it can be reflected on the environment and society, if its discharge is unappropriated. Therefore, it is indispensable a valuable careful to establish and maintain its management. The traditional treatment of produced water, usualy includes both tecniques, flocculation and flotation. At flocculation processes, there are traditional floculant agents that arent well specified by tecnichal information tables and still expensive. As for the flotation process, its the step in which is possible to separate the suspended particles in the effluent. The dissolved air flotation (DAF) is a technique that has been consolidating economically and environmentally, presenting great reliability when compared with other processes. The DAF is presented as a process widely used in various fields of water and wastewater treatment around the globe. In this regard, this study was aimed to evaluate the potential of an alternative natural flocculant agent based on Moringa oleifera to reduce the amount of oil and grease (TOG) in produced water from the oil industry by the method of flocculation/DAF. the natural flocculant agent was evaluated by its efficacy, as well as its efficiency when compared with two commercial flocculant agents normally used by the petroleum industry. The experiments were conducted following an experimental design and the overall efficiencies for all flocculants were treated through statistical calculation based on the use of STATISTICA software version 10.0. Therefore, contour surfaces were obtained from the experimental design and were interpreted in terms of the response variable removal efficiency TOG (total oil and greases). The plan still allowed to obtain mathematical models for calculating the response variable in the studied conditions. Commercial flocculants showed similar behavior, with an average overall efficiency of 90% for oil removal, however it is the economical analysis the decisive factor to choose one of these flocculant agents to the process. The natural alternative flocculant agent based on Moringa oleifera showed lower separation efficiency than those of commercials one (average 70%), on the other hand this flocculant causes less environmental impacts and its less expensive
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Ethanol withdrawn individuals present a wealth of signs and symptoms, some of them related with anxiety. To better understand brain areas involved in anxiety caused by ethanol abstinence, preclinical studies have been employing models of ethanol consumption followed by withdrawal in rodents submitted to behavioral tests of anxiety, such as the elevated plus-maze. The aim of this study was to investigate if short- or long-term ethanol withdrawal could alter both anxiety-related behaviors in the elevated plus-maze (EPM) and open field tests and the number of serotonin immunorreactive cels in the dorsal raphe nucleus, a midbrain area associated with anxiety. Female Wistar rats (90 days old) were submitted to increasing concentrations of ethanol (2% for 3 days, 4% for 3 days and 6% for 15 days) as the only source of liquid diet and the control group received water ad libitum. Both groups received food ad libitum. In the behavioral experiments, on 21st day of consumption, ethanol was substituted by water (withdrawal) and 72 h or 21 days after withdrawal animals were submitted to the EPM, where it was evaluated the percentage of time and entries in the open arms and the entries in the enclosed arms during 5 minutes. Twenty and four hours after testing in the EPM, animals were submitted to the open field test for 15 minutes, where the distance traveled by the animals was observed along this period. During the first 5 minutes, the distance traveled, entries and time spent in the center of the test were analyzed. In the immunohistochemistry study, animals were submitted to 21 days of consumption of ethanol followed or not by 72 hours and 21 days of withdrawal previously perfusion, brain tissue preparation and quantification of serotonin dyed cells in the dorsal and caudal portions in the dorsal raphe nucleus. Behavioral data showed that both short- and long-term ethanol withdrawals reduced the open arms exploration in the EPM. In the open field test there were no locomotor activity changes during the total 15 minutes; however, longterm ethanol withdrawal reduced the exploration in the center of the open field during the first 5 minutes. In the immunohistochemistry step, there were no differences, when short- and long-term withdrawn groups were compared with control group; nevertheless, the chronic consumption of ethanol decreased the number of serotonergic immunorreactive cells in the dorsal part of dorsal raphe nucleus. Taken together, results here obtained suggest that both short- and long-term ethanol withdrawals promoted an anxiogenic-like effect that was not related with changes in the serotonin immunorreactivity in the dorsal and caudal parts of the dorsal raphe nucleus.
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Camu-camu (Myrciaria dubia H.B.K. (McVaugh)) is a native Amazon fruit, recognized worldwide as one of the main natural sources of ascorbic acid. Due to its great acidity, this fruit is generally consumed after processing into juice or as ingredient in food preparations. As a co-product of the camu-camu processing, a significant amount of agroindustrial residue is generated. Despite the studies showing the bioactive value and biological potential of the fruit, few studies have approached the possible processing techniques, transformation and preservation of camu-camu fruits and its agroindustrial pomace. Therefore, the present work has the objective of evaluating two different drying processes applied to camu-camu pomace (peel and seeds with residual pulp), freeze drying and hot air drying, in order to obtain a functional fruit product. This thesis was divided into three stages: the first one shows the studies related to the freeze drying and hot air drying, where we demonstrated the impact of the selected drying techniques on the bioactive components of camu-camu, taking the fresh pomace as the control group. Among the investigated conditions, the groups obtained at 50C and 4 m/s (SC50) and 80C and 6 m/s (SC80) were selected as for further studies, based on their ascorbic acid final content and Folin-Ciocalteau reducing capacity. In addition to SC50 and SC80, the fresh pomace (RF) and freeze dried (RL) samples were also evaluated in these further stages of the research. Overall, the results show higher bioactive concentration in the RF samples, followed by RL, SC50 and SC80. On the second step of the research, the antioxidant, antimicrobial and antienzymatic activities were evaluated and the same tendency was observed. It was also reported, for the first time in the literature, the presence of syringic acid in dried camu-camu pomace. In the third and final stage of the research, it was investigated the effect of dried camu-camu on aging and neuroprotective disorders, using the in vivo model C.elegans. It was observed that camu-camu extracts were able to modulate important signaling genes relevant to thermal and oxidative stresses (p < 0.05). The polar acid, polar basic and polar neutral fractions obtained from the low molecular extracts of SC50 were able to extend the lifespan of wild type N2 C. elegans in 20% and 13% (p < 0.001). Results also showed that the paralysis induced by the 1-42 amyloid was significantly (p < 0.0001) retarded in CL4176 worms. Similarly, the camu-camu extracts attenuated the dopaminergic induction associated to Parkinsons disease. Finally, a global analysis of the data presented here reveal that the camu-camu pomace, a co-product obtained from the industrial processing of a native Brazilian fruit, is a relevant natural source of health relevant compounds. This thesis, shows for the first time, the multifunctionality of camu-camu pomace, a natural resource still underexploited for scientific, commercial and technological purposes.
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In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
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In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
Resumo:
Snakebites are a serious public health problem in tropical and subtropical countries and Bothrops genus is responsible for the accidents in Brazil and throughout Latin America (90% of cases). The local effects (pain, edema, hemorrhage and myonecrosis) and systemic (cardiovascular alterations, shock and blood clotting disorders) caused by the venom of Bothrops are due to the numerous protein and non-protein components, which are part of the constitution of the poison. The only form of therapy is scientifically validated antivenom serum therapy which, however, is not effective with respect to local effects produced, risk of immunological reactions, high cost and difficult access in some regions. Thus, the search for new alternatives to serum therapy becomes important, and in this context, many medicinal plants have been highlighted by the popular use as antiophidic. Among these plants, we can mention the species Jatropha mollissima (Euphorbiaceae) which has popular use in traditional medicine as antiophidic, anti-inflammatory, antimicrobial and antipyretic. Therefore, this study aims to evaluate the neutralizing potential of local effects induced by the venom of Bothrops erythromelas and Bothrops jararaca with the aqueous extract of the leaves of J. mollissima. The leaf extracts were prepared by decoction, fractionated (by liquid-liquid partition) and characterized by thin layer chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Antiophidic activity of the extract was evaluated in model of paw edema, peritonitis, bleeding and myotoxicity induced by venoms of B. jararaca and B. erythromelas. In all models, the extract was evaluated by intraperitoneal route at the doses of 50, 100 and 200 mg/kg, administered 30 minutes prior to injection of the venom (pretreatment protocol). Stains suggestive of the presence of flavonoids: apigenin, luteolin, orientin, isoorientin, vitexin and vitexin-2-O-rhamnoside were detected in the extract by co-CCD. By means of HPLC were identified isoorientin, orientin, vitexin and isovitexin. All tested doses of J. mollissima extract reduced the paw edema induced by the venom with intensity similar to dexamethasone. The aqueous extract of J. mollissima leaves on all evaluated doses, inhibited cell migration induced by B. jararaca and B. erythromelas promoting inhibition of recruitment of mononuclear cells and the polymorphonuclear cells. Local bleeding induced by B. jararaca venom was significantly inhibited by the extract. Both venoms were inhibited by the extract in myotoxic activity. These results indicate that the aqueous extract of J. mollissima leaves have snakebite potential, particularly with respect to local effects, which may justify the use of this plant in traditional medicine and complementary therapy as anti-venom serum.
Resumo:
Snakebites are a serious public health problem in tropical and subtropical countries and Bothrops genus is responsible for the accidents in Brazil and throughout Latin America (90% of cases). The local effects (pain, edema, hemorrhage and myonecrosis) and systemic (cardiovascular alterations, shock and blood clotting disorders) caused by the venom of Bothrops are due to the numerous protein and non-protein components, which are part of the constitution of the poison. The only form of therapy is scientifically validated antivenom serum therapy which, however, is not effective with respect to local effects produced, risk of immunological reactions, high cost and difficult access in some regions. Thus, the search for new alternatives to serum therapy becomes important, and in this context, many medicinal plants have been highlighted by the popular use as antiophidic. Among these plants, we can mention the species Jatropha mollissima (Euphorbiaceae) which has popular use in traditional medicine as antiophidic, anti-inflammatory, antimicrobial and antipyretic. Therefore, this study aims to evaluate the neutralizing potential of local effects induced by the venom of Bothrops erythromelas and Bothrops jararaca with the aqueous extract of the leaves of J. mollissima. The leaf extracts were prepared by decoction, fractionated (by liquid-liquid partition) and characterized by thin layer chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Antiophidic activity of the extract was evaluated in model of paw edema, peritonitis, bleeding and myotoxicity induced by venoms of B. jararaca and B. erythromelas. In all models, the extract was evaluated by intraperitoneal route at the doses of 50, 100 and 200 mg/kg, administered 30 minutes prior to injection of the venom (pretreatment protocol). Stains suggestive of the presence of flavonoids: apigenin, luteolin, orientin, isoorientin, vitexin and vitexin-2-O-rhamnoside were detected in the extract by co-CCD. By means of HPLC were identified isoorientin, orientin, vitexin and isovitexin. All tested doses of J. mollissima extract reduced the paw edema induced by the venom with intensity similar to dexamethasone. The aqueous extract of J. mollissima leaves on all evaluated doses, inhibited cell migration induced by B. jararaca and B. erythromelas promoting inhibition of recruitment of mononuclear cells and the polymorphonuclear cells. Local bleeding induced by B. jararaca venom was significantly inhibited by the extract. Both venoms were inhibited by the extract in myotoxic activity. These results indicate that the aqueous extract of J. mollissima leaves have snakebite potential, particularly with respect to local effects, which may justify the use of this plant in traditional medicine and complementary therapy as anti-venom serum.