256 research outputs found
In situ surface coverage analysis of RuO<sub>2</sub>-catalysed HCl oxidation reveals the entropic origin of compensation in heterogeneous catalysis
In heterogeneous catalysis, rates with Arrhenius-like temperature dependence are ubiquitous. Compensation phenomena, which arise from the linear correlation between the apparent activation energy and the logarithm of the apparent pre-exponential factor, are also common. Here, we study the origin of compensation and find a similar dependence on the rate-limiting surface coverage term for each Arrhenius parameter. This result is derived from an experimental determination of the surface coverage of oxygen and chlorine species using temporal analysis of products and prompt gamma activation analysis during HCl oxidation to Cl2 on a RuO2 catalyst. It is also substantiated by theory. We find that compensation phenomena appear when the effect on the apparent activation energy caused by changes in surface coverage is balanced out by the entropic configuration contributions of the surface. This result sets a new paradigm in understanding the interplay of compensation effects with the kinetics of heterogeneously catalysed processes
Timing influenced force directed floorplanning
We present a timing driven floorplanning program for general cell layouts. The approach used combines quality of force directed approach with that of constraint graph approach. A floorplan solution is produced in two steps. First a timing and connectivity driven topological arrangement is obtained using a force directed approach. In the second step, the topological arrangement is transformed into a legal floorplan. The objective of the second step is to minimize the overall area of the floorplan. The floorplanner is validated with circuits of sizes varying from 7 to 125 block
Timing influenced force directed floorplanning
We present a timing driven floorplanning program for general cell layouts. The approach used combines quality of force directed approach with that of constraint graph approach. A floorplan solution is produced in two steps. First a timing and connectivity driven topological arrangement is obtained using a force directed approach. In the second step, the topological arrangement is transformed into a legal floorplan. The objective of the second step is to minimize the overall area of the floorplan. The floorplanner is validated with circuits of sizes varying from 7 to 125 block
A TRANSNACIONALIDADE DOS DIREITOS HUMANOS E O ENSINO JURÍDICO NO BRASIL
O presente artigo possui por objeto de estudo as críticas que recebe o Ensino Jurídico no Brasil e os Direitos Humanos como matéria estudada nos Cursos de Direito. A problemática geral com a qual trabalha é a de se, identificadas no Ensino Jurídico no Brasil as críticas que serão apresentadas, teria o ensino dos Direitos Humanos alguma possibilidade de realizar modificações nesta situação? A hipótese da pesquisa é a de que, pela sua natureza, a matéria estudada em Direitos Humanos possui elementos que podem, quando bem trabalhados pelos docentes e discentes, superar alguns problemas antigos e bastante arraigados do Ensino Jurídico. Neste sentido, o objetivo da pesquisa é verificar as possibilidades da hipótese levantada. A falta de preparo dos egressos dos cursos de Direito não é novidade, e revela a má qualidade do ensino nas Faculdades de Direito de nosso país. O despreparo é generalizado atingindo tanto a formação científica quanto a técnica. Para tanto, no primeiro item do artigo são estudadas as várias críticas ao Ensino Jurídico que podem ser subdivididas em: questões estruturais, questões funcionais e questões operacionais. No âmbito da estrutura verificam-se críticas ao paradigma epistemológico. No âmbito funcional, críticas à formação para o mercado de trabalho que levam a problemas de identidade e legitimidade dos bacharéis. Por fim, no âmbito operacional as críticas serão dirigidas à metodologia didático-pedagógica e ao currículo dos cursos. No último item essas críticas são reapresentadas em contraponto com o conteúdo, metodologia e conceitos transnacionais que podem ser trabalhados ao se ministrar os Direitos Humanos no curso de graduação em Direito. Trata-se de um estudo descritivo e exploratório, desenvolvido com base na pesquisa bibliográfica e histórica para qual se utiliza do método indutivo. Na Conclusão recupera-se a hipótese de trabalho e verifica-se que existem várias potencialidades na matéria de Direitos Humanos para se superar os problemas do Ensino Jurídico, levando a uma formação interdisciplinar, politica e emancipatória dos discentes
An improved parallel singular value algorithm and its implementation for multicore hardware
OptCircuit: An optimization based method for computational design of genetic circuits
<p>Abstract</p> <p>Background</p> <p>Recent years has witnessed an increasing number of studies on constructing simple synthetic genetic circuits that exhibit desired properties such as oscillatory behavior, inducer specific activation/repression, etc. It has been widely acknowledged that that task of building circuits to meet multiple inducer-specific requirements is a challenging one. This is because of the incomplete description of component interactions compounded by the fact that the number of ways in which one can chose and interconnect components, increases exponentially with the number of components.</p> <p>Results</p> <p>In this paper we introduce OptCircuit, an optimization based framework that automatically identifies the circuit components from a list and connectivity that brings about the desired functionality. Multiple literature sources are used to compile a comprehensive compilation of kinetic descriptions of promoter-protein pairs. The dynamics that govern the interactions between the elements of the genetic circuit are currently modeled using deterministic ordinary differential equations but the framework is general enough to accommodate stochastic simulations. The desired circuit response is abstracted as the maximization/minimization of an appropriately constructed objective function. Computational results for a toggle switch example demonstrate the ability of the framework to generate the complete list of circuit designs of varying complexity that exhibit the desired response. Designs identified for a genetic decoder highlight the ability of OptCircuit to suggest circuit configurations that go beyond the ones compatible with digital logic-based design principles. Finally, the results obtained from the concentration band detector example demonstrate the ability of OptCircuit to design circuits whose responses are contingent on the level of external inducer as well as pinpoint parameters for modification to rectify an existing (non-functional) biological circuit and restore functionality.</p> <p>Conclusion</p> <p>Our results demonstrate that OptCircuit framework can serve as a design platform to aid in the construction and finetuning of integrated biological circuits.</p
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