oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 322 )

2018 ( 614 )

2017 ( 623 )

2016 ( 793 )

Custom range...

Search Results: 1 - 10 of 456162 matches for " Igor de Sousa;Binda Júnior "
All listed articles are free for downloading (OA Articles)
Page 1 /456162
Display every page Item
Association of HTLV-I with Arnold Chiari syndrome and syringomyelia
Viana, Gra?a Maria de Castro;Diniz Neto, Jo?o Arnaud;Furtado, Igor de Sousa;Binda Júnior, José Roberto;Tanaka, Bárbara Neiva;Nascimento, Maria do Desterro Soares Brand?o;
Brazilian Journal of Infectious Diseases , 2008, DOI: 10.1590/S1413-86702008000600018
Abstract: htlv-i is associated with a broad spectrum of manifestations, including tropical spastic paraparesis and adult t-cell leukemia/lymphoma. arnold chiari syndrome is a condition characterized by herniation of the cerebellar tonsils through the foramen magnum. this condition should be suspected in all patients with headache and impaired motor coordination. syringomyelia is a developmental anomaly that leads to the formation of an intramedullary cavity. its clinical presentation is classically characterized by syringomyelic dissociation of sensation, with suspended distribution in the proximal portion of the trunk and upper limbs and preservation in other regions. we report here a case of association of the three diseases, which is rare in clinical practice, illustrating the difficulty in the diagnosis and therapeutic management of these conditions.
Leishmanicidal activity and cytotoxicity of compounds from two Annonacea species cultivated in Northeastern Brazil
Vila-Nova, Nadja Soares;Morais, Selen Maia de;Falc?o, Maria José Cajazeiras;Machado, Lyeghyna Karla Andrade;Beviláqua, Cláudia Maria Leal;Costa, Igor Rafael Sousa;Brasil, Nilce Viana Gramosa Pompeu de Sousa;Andrade Júnior, Heitor Franco de;
Revista da Sociedade Brasileira de Medicina Tropical , 2011, DOI: 10.1590/S0037-86822011000500007
Abstract: introduction: visceral leishmaniasis is endemic in 88 countries, with a total of 12 million people infected and 350 million at risk. in the search for new leishmanicidal agents, alkaloids and acetogenins isolated from leaves of annona squamosa and seeds of annona muricata were tested against promastigote and amastigote forms of leishmania chagasi. methods: methanol-water (80:20) extracts of a. squamosa leaves and a. muricata seeds were extracted with 10% phosphoric acid and organic solvents to obtain the alkaloid and acetogenin-rich extracts. these extracts were chromatographed on a silica gel column and eluted with a mixture of several solvents in crescent order of polarity. the compounds were identified by spectroscopic analysis. the isolated compounds were tested against leishmania chagasi, which is responsible for american visceral leishmaniasis, using the mtt test assay. the cytotoxicity assay was evaluated for all isolated compounds, and for this assay, raw 264.7 cells were used. results: o-methylarmepavine, a benzylisoquinolinic alkaloid, and a c37 trihydroxy adjacent bistetrahydrofuran acetogenin were isolated from a. squamosa, while two acetogenins, annonacinone and corossolone, were isolated from a. muricata. against promastigotes, the alkaloid showed an ic50 of 23.3 μg/ml, and the acetogenins showed an ic50 ranging from 25.9 to 37.6 μg/ml; in the amastigote assay, the ic50 values ranged from 13.5 to 28.7 μg/ml. the cytotoxicity assay showed results ranging from 43.5 to 79.9 μg/ml. conclusions: these results characterize a. squamosa and a. muricata as potential sources of leishmanicidal agents. plants from annonaceae are rich sources of natural compounds and an important tool in the search for new leishmanicidal therapies.
Large- and Medium-Sized Land Mammals of Northeast Marajó Island, Lower Amazon, Brazil  [PDF]
Salvatore Siciliano, Renata Emin-Lima, Alexandra F. Costa, José de Sousa e Silva Júnior
Natural Resources (NR) , 2015, DOI: 10.4236/nr.2015.61005
Abstract: Marajó, located in the lower Amazon, Brazil, is one of the largest river islands in the world. Most of the island is subject to tidal or seasonal flooding. Despite its historical, cultural and geographical importance, Marajó Island remains relatively less investigated in terms of mammal diversity, ecology and community structure than the rest of the Amazon. This scenario has motivated the presentation of this list of land mammals of eastern Marajó Island. Two field surveys were conducted in the course of 7-11 December 2012 and 17-25 October 2013 in Jaranduba, Dunas and Ribanceira Farms, northeast portions of Marajó Island. A total of 23 large and medium-sized land mammal species were recorded in the study area. These farms host a representative mammal community of northeastern Marajó, an area lacking previous faunal studies. Human pressure over centuries has deeply modified the environment in Marajó. Therefore, striking evidence of a long human-populated past in this island is in accordance to many other sites throughout the Amazon plain. The result of a land mammal survey in northeastern Marajó is a clear evidence of past and present human interference in the island. Even though Marajó Island has exalted mammal diversity, it will be much higher if long-term studies are effectively implemented.
Synthesis of ZSM-22 in Static and Dynamic System Using Seeds  [PDF]
Lenivaldo V. de Sousa Júnior, Antonio O. S. Silva, Bruno J. B. Silva, Soraya L. Alencar
Modern Research in Catalysis (MRC) , 2014, DOI: 10.4236/mrc.2014.32007
Abstract:

ZSM-22 was synthesized using various sources of silica, organic template 1,6-diaminohexane, under hydrothermal conditions, with and without agitation during crystallization. Subsequently, the crystallized material was used as seeds to accelerate the crystallization process. Characterization of the ZSM-22 samples was performed by XRD, ATG/DTG and FT-IR. It was found that it is possible to synthesize ZSM-22 employing colloidal silica and pyrolytic silica as silicon sources only if the system is stirred during crystallization. The crystallization time for these systems was 13 hours, longer times of crystallization do not significantly increase the crystallinity of the sample. The addition of seeds significantly accelerates the crystallization of ZSM-22, reducing the crystallization time to only 7 hours, with stirring and with systems employing colloidal silica.

Thermoeconomic Evaluation of Cogeneration Systems for a Chemical Plant
Maurilo de Sousa Teixeira,Silvio de Oliveira Júnior
International Journal of Thermodynamics , 2001, DOI: 10.5541/ijot.76
Abstract: This paper presents the comparative exergy and thermoeconomic analysis of three cogeneration systems designed for a chemical plant. These systems must produce steam and electricity for the processes of the plant. These comparisons are developed for two scenarios: in the first one the systems generate steam and electricity for the plant and in the second one the systems generate steam and electricity for the plant and export electricity. The cogeneration systems are: a steam cycle with condensation-extraction steam turbine, a gas turbine based system and a combined cycle based system. The exergy analysis developed for the cogeneration systems evaluates the exergy efficiency and the exergy destroyed in each set of equipment, as well as the overall cogeneration plant performance. The overall exergy efficiency of the plants and the exergy efficiency of each set of equipment are defined as the ratio of the useful exergetic effect of the equipment/system to the consumed exergy. The importance of each set of equipment in the overall exergy efficiency is quantified by the use of the factor f, defined as the ratio of the supplied exergy in a particular set of equipment to the consumed exergy in the plant. Equality and extraction cost partition methods are utilised (in the steam and gas turbines) in order to determine the production costs of steam (at 6 and 18 bar) and electricity, for each one of the considered operating scenarios of the plants. This comparison indicates the feasibility of the cogeneration systems for each production scenario.
Análise da eficiência dos portos da regi o Nordeste do Brasil baseada em Análise Envoltória de Dados
José Nauri Cazuza De Sousa Júnior,Ernesto Ferreira Nobre Júnior,Bruno De Athayde Prata
Sistemas & Gest?o , 2009,
Abstract: O sistema portuário é elemento chave para o desenvolvimento de determinada regi o. Nesse contexto, a avalia o de desempenho torna-se fundamental para o monitoramento e o aprimoramento das atividades do setor em foco. A Análise Envoltória de Dados (Data Envelopment Analysis – DEA) é uma técnica, baseada em programa o matemática, que analisa, com base nos recursos e produtos utilizados em um dado processo, a eficiência relativa de um conjunto de unidades tomadoras de decis o. O presente trabalho teve como objetivo elaborar um modelo para a medi o da eficiência relativa dos portos da regi o Nordeste do Brasil, adotando o modelo DEA orientado a inputs. Foram considerados dois inputs (comprimento dos ber os e calado admissível) e um output (movimenta o, em toneladas ou em número de contêineres). Este modelo foi aplicado aos 22 portos da regi o supracitada, sendo estes classificados por tipo de carga. Pela análise realizada, foi possível constatar que a maioria dos portos do Nordeste tem subaproveitamento de sua infraestrutura. A obten o das eficiências dos portos nordestinos permitiu observar que estes têm capacidade de movimentar maior quantidade de mercadorias com os mesmos inputs (especialmente a infra-estrutura analisada). A Análise de Envoltória de Dados mostrou-se como técnica que pode contribuir com os tomadores de decis es para a análise, a gest o e o planejamento no setor portuário.
Efficiency analysis of Brazilian Northeeast ports using Data Envelopment Analysis
José Nauri Cazuza de Sousa Júnior,Ernesto Ferreira Nobre Júnior,Bruno de Athayde Prata
Sistemas & Gest?o , 2008,
Abstract: The port system is a key element to the economic development of a region. In this sense, theperformance evaluation is fundamental to the monitoring and improving the activities ofabove mentioned sector. Data Envelopment Analysis – DEA is a method, based onmathematical programming, which analyses, with agreement to a set of inputs and outputs ofa process, the relative efficiency of a group of decision making units. The objective of thiswork was create a model to evaluate the performance of the ports in Northeast of Brazil,adopting a model oriented to inputs. It was considered two inputs (length of the pier andadmissible depth) and one output (cargo handling, in weight or number of containers). Thismodel was applied to the 22 ports of the above mentioned region. These ports wereclassified for type of cargo. The analysis made possible to observe that the majority of portslocated in the Northeast of Brazil uses inefficiently its infrastructures. The determination ofthe relative efficiencies of these ports allows observe that its have capacity to handling amajor quantity of goods with the same inputs. As conclusions, one can observe that DEA isa feasible and useful technique to the analysis, management and planning in the port sector,aiding the decision making process.
Controle de rob?s móveis utilizando o modelo cinemático
Sousa Júnior, Celso de;Hemerly, Elder Moreira;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2003, DOI: 10.1590/S0103-17592003000400006
Abstract: this work presents the stability proof for the mobile robot kinematic controller, where the guidance point is different from the medium point of wheel axis. the proof is based on the lyapunov second method. simulation results assert the theoretical development.
Uncertainties in the Amazon hydropower development: Risk scenarios and environmental issues around the Belo Monte dam
Wilson Cabral de Sousa Júnior,John Reid
Water Alternatives , 2010,
Abstract: The Amazon region is the final frontier and central focus of Brazilian hydro development, which raises a range of environmental concerns. The largest project in the Amazon is the planned Belo Monte Complex on the Xingu river. If constructed it will be the second biggest hydroelectric plant in Brazil, third largest on earth. In this study, we analyse the private and social costs, and benefits of the Belo Monte project. Furthermore, we present risk scenarios, considering fluctuations in the project’s feasibility that would result from variations in total costs and power. For our analysis, we create three scenarios. In the first scenario Belo Monte appears feasible, with a net present value (NPV) in the range of US$670 million and a rate of return in excess of the 12% discount rate used in this analysis. The second scenario, where we varied some of the project costs and assumptions based on other economic estimates, shows the project to be infeasible, with a negative NPV of about US$3 billion and external costs around US$330 million. We also conducted a risk analysis, allowing variation in several of the parameters most important to the project’s feasibility. The simulations brought together the risks of cost overruns, construction delays, lower-than-expected generation and rising social costs. The probability of a positive NPV in these circumstances was calculated to be just 28%, or there is a 72% chance that the costs of the Belo Monte dam will be greater than the benefits. Several WCD recommendations are not considered in the project, especially those related to transparency, social participation in the discussion, economic analysis and risk assessment, and licensing of the project. This study underscores the importance of forming a participatory consensus, based on clear, objective information, on whether or not to build the Belo Monte dam.
Controle de rob s móveis utilizando o modelo cinemático
Sousa Júnior Celso de,Hemerly Elder Moreira
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2003,
Abstract: Este trabalho apresenta a prova de estabilidade para controladores de modelos cinemáticos de rob s móveis, onde o ponto de guiamento é diferente do ponto médio do eixo das rodas. A prova é baseada no segundo método de Lyapunov. Simula es comprovam o desenvolvimento teórico.
Page 1 /456162
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.