Rational approximations of the Arrhenius integral using Jacobi fractions and gaussian quadrature

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da temperatura e taxa de cisalhamento nas propriedades de escoamento da polpa de Cupuaçu (T. grandiflorum Schum) integral

O comportamento reológico da polpa de cupuaçu integral foi determinado na faixa de temperatura de 10 a 60ºC. Os efeitos da temperatura e da taxa de deformação foram avaliados por meio de testes em cisalhamento estacionário. As análises reológicas foram conduzidas num reômetro Thermo Haake RheoStress 1. Os reogramas foram descritos pelos modelos reológicos de Ostwald-de-Waelle e o de Herschel-Bulkley. As curvas de escoamento mais bem ajustadas pelo modelo de Ostwald-de-Waelle. O produto apresentou comportamento pseudoplástico, e o índice de comportamento de fluxo (n) decresceu com o aumento da temperatura. O efeito da temperatura sobre a viscosidade aparente foi descrita por uma equação tipo Arrhenius e discutida em termos de energia de ativação. Essa energia aumentou com o aumento da taxa de deformação, sendo obtidos valores na faixa de 1 a 2 kcal/gmol.

Shelf-life of a 2.5% sodium hypochlorite solution as determined by arrhenius equation

Accelerated stability tests are indicated to assess, within a short time, the degree of chemical degradation that may affect an active substance, either alone or in a formula, under normal storage conditions. This method is based on increased stress conditions to accelerate the rate of chemical degradation. Based on the equation of the straight line obtained as a function of the reaction order (at 50 and 70 ºC) and using Arrhenius equation, the speed of the reaction was calculated for the temperature of 20 ºC (normal storage conditions). This model of accelerated stability test makes it possible to predict the chemical stability of any active substance at any given moment, as long as the method to quantify the chemical substance is available. As an example of the applicability of Arrhenius equation in accelerated stability tests, a 2.5% sodium hypochlorite solution was analyzed due to its chemical instability. Iodometric titration was used to quantify free residual chlorine in the solutions. Based on data obtained keeping this solution at 50 and 70 ºC, using Arrhenius equation and considering 2.0% of free residual chlorine as the minimum acceptable threshold, the shelf-life was equal to 166 days at 20 ºC. This model, however, makes it possible to calculate shelf-life at any other given temperature.

Integral Piezoactuator System with Optimum Placement of Functionally Graded Material - A Topology Optimization Paradigm

Piezoactuators consist of compliant mechanisms actuated by two or more piezoceramic devices. During the assembling process, such flexible structures are usually bonded to the piezoceramics. The thin bonding layer(s) between the compliant mechanism and the piezoceramic may induce undesirable behavior, including unusual interfacial nonlinearities. This constitutes a drawback of piezoelectric actuators and, in some applications, such as those associated to vibration control and structural health monitoring (e. g., aircraft industry), their use may become either unfeasible or at least limited. A possible solution to this standing problem can be achieved through the functionally graded material concept and consists of developing `integral piezoactuators`, that is those with no bonding layer(s) and whose performance can be improved by tailoring their structural topology and material gradation. Thus, a topology optimization formulation is developed, which allows simultaneous distribution of void and functionally graded piezoelectric materials (including both piezo and non-piezoelectric materials) in the design domain in order to achieve certain specified actuation movements. Two concurrent design problems are considered, that is the optimum design of the piezoceramic property gradation, and the design of the functionally graded structural topology. Two-dimensional piezoactuator designs are investigated because the applications of interest consist of planar devices. Moreover, material gradation is considered in only one direction in order to account for manufacturability issues. To broaden the range of such devices in the field of smart structures, the design of integral Moonie-type functionally graded piezoactuators is provided according to specified performance requirements.

Calculation of line integrals in boundary integral methods

We propose quadrature rules for the approximation of line integrals possessing logarithmic singularities and show their convergence. In some instances a superconvergence rate is demonstrated.

A finite integral transform technique for solving the diffusion-reaction equation with Michaelis-Menten kinetics

An approximate analytical technique employing a finite integral transform is developed to solve the reaction diffusion problem with Michaelis-Menten kinetics in a solid of general shape. A simple infinite series solution for the substrate concentration is obtained as a function of the Thiele modulus, modified Sherwood number, and Michaelis constant. An iteration scheme is developed to bring the approximate solution closer to the exact solution. Comparison with the known exact solutions for slab geometry (quadrature) and numerically exact solutions for spherical geometry (orthogonal collocation) shows excellent agreement for all values of the Thiele modulus and Michaelis constant.

Use of an Arrhenius model to predict rheological behaviour in some Australian honeys

Rheological properties of nine unprocessed unifloral Australian honeys (bloodwood, blue top iron bark, gum top, heath, narrow leafed iron bark, stringy bark, tea tree yapunyah and yellow box) were analysed over a range of temperatures (1-40 degreesC) The temperature effect on the viscosity follow ed an Arrhenius-type relationship and ail honey varieties exhibited Newtonian behaviour. if the Arrhenius equation constants (mu (0) and E-a) for a particular honey are known, the Arrhenius model can be used to calculate the viscosity of these honeys at specific temperatures, negating the need for tedious viscosity determination. (C) 2000 Academic Press.

Is the irritable bladder associated with anterior compartment relaxation? A critical look at the 'integral theory of pelvic floor dysfunction'

The 'integral theory of pelvic floor dysfunction', first proposed by Petros and Ulmsten in 1990, claims that anterior vaginal wall relaxation is associated with symptoms of urgency, frequency, nocturia and urge incontinence. A retrospective study was designed to test this hypothesis. Imaging data and urodynamic reports from 272 women suffering from symptoms of lower urinary tract dysfunction were evaluated. Opening of the retrovesical angle, bladder neck descent, urethral rotation and descent of a cystocele during Valsalva were used to quantify anterior vaginal wall laxity None of the tested parameters were associated with symptoms and signs of detrusor overactivity. On the contrary, patients with higher grades of urethral and bladder descent were less likely to suffer from nocturia and urge incontinence and were less likely to leave sensory urgency and detrusor instability diagnosed on urodynamic testing. The findings of this study therefore do not support this hypothesis of the 'integral theory'.

Theory and applications of fuzzy Volterra integral equations

Formulations of fuzzy integral equations in terms of the Aumann integral do not reflect the behavior of corresponding crisp models. Consequently, they are ill-adapted to describe physical phenomena, even when vagueness and uncertainty are present. A similar situation for fuzzy ODEs has been obviated by interpretation in terms of families of differential inclusions. The paper extends this formalism to fuzzy integral equations and shows that the resulting solution sets and attainability sets are fuzzy and far better descriptions of uncertain models involving integral equations. The investigation is restricted to Volterra type equations with mildly restrictive conditions, but the methods are capable of extensive generalization to other types and more general assumptions. The results are illustrated by integral equations relating to control models with fuzzy uncertainties.

Educação infantil em jornada de tempo integral : dilemas e perspectivas

Vania Carvalho de Araújo (Org.)

Estudantes público-alvo da educação especial na educação em tempo integral : um estudo em Vitória-ES

Este estudo tem como tema “Estudantes Público-Alvo da Educação Especial na Educação em Tempo Integral no Município de Vitoria-ES”. Seu objetivo geral foi investigar os modos de atendimento aos estudantes público-alvo da Educação Especial do Programa Educação em Tempo Integral – Educação Ampliada, oferecido pelo ensino público municipal nas Escolas de Ensino Fundamental (EMEFs) do município de Vitória, pela fala dos gestores e executores do programa. Seus objetivos específicos foram compreender a configuração da proposta de Educação em Tempo Integral – Educação Ampliada no município de Vitória-ES; caracterizar o conjunto de estudantes público-alvo da Educação Especial participantes do Programa Educação em Tempo Integral – Educação Ampliada no município; compreender os sentidos e significados da inclusão de estudantes público-alvo da Educação Especial no Programa Educação em Tempo Integral – Educação Ampliada no município de Vitória-ES. Trata-se de pesquisa qualitativa, cuja metodologia envolveu revisão de literatura e estudo de caso. O instrumento de pesquisa foi uma entrevista semiestruturada, por permitir explorar mais amplamente as abordagens e proporcionar aos entrevistados maior liberdade para emitir as suas opiniões. Os sujeitos da pesquisa foram os gestores responsáveis pelo desenvolvimento do Programa Educação em Tempo Integral – Educação Ampliada da Secretaria Municipal de Educação do município de Vitória (Seme) e a equipe de uma das EMEFs que compôs o grupo focal, profissionais diretamente envolvidos no exercício das práticas pedagógicas com os estudantes matriculados no Programa da Unidade de Ensino. Os resultados das análises da pesquisa foi que a Educação em Tempo Integral – Educação Ampliada é uma realidade no município de Vitória-ES, desde a sua implantação em 1989. O programa atende hoje a 3.203 estudantes. Desse total, apenas 35, ou seja, 1,9%, compõem o público-alvo da Educação Especial atendido pelo programa em foco. A análise das informações documentais, os relatos dos gestores que se revezaram desde a implantação do Peti e as entrevistas com os sujeitos desta pesquisa revelaram que a educação em tempo integral se processa no município de Vitória de forma lenta e descontínua, especialmente por ocasião do revezamento entre uma administração e outra, quando muda a gestão política.

La adopción del cuadro de mando integral en organizaciones portuguesas: variables contingentes e institucionales

Este artículo tiene como objetivo identificar y analizar un conjunto de variables contingentes e institucionales que pueden potencialmente influir en el conocimiento e implementación del Cuadro de Mando Integral (CMI) en las organizaciones portuguesas pertenecientes al sector público y privado.

Determinantes de la adopción del cuadro de mando integral en organizaciones portuguesas del setor público y privado

Esta comunicación tiene como objetivo identificar y analizar un conjunto de variables que pueden potencialmente influir en la adopción del Cuadro de Mando Integral (CMI) en organizaciones públicas y privadas portuguesas. Definimos un conjunto de hipótesis de investigación y para comprobar empíricamente las hipótesis formuladas hemos recurrido a los datos obtenidos mediante la aplicación de un cuestionario postal a 591 organizaciones públicas (ayuntamientos, hospitales, empresas municipales y empresas intermunicipales) y 549 organizaciones privadas (grandes empresas y pequeñas y medianas empresas) portuguesas, con una tasa de respuesta del 31,3%. Los resultados obtenidos indican que el compromiso de la alta dirección, el desarrollo de mapas estratégicos y el establecimiento de relaciones causa-efecto son factores que están asociados con la implementación del CMI.

La adopción del cuadro de mando integral en organizaciones portuguesas: variables contingentes e institucionales

Esta comunicación tiene como objetivo identificar y analizar un conjunto de variables contingentes e institucionales que pueden potencialmente influir en el conocimiento e implementación del Cuadro de Mando Integral (CMI) en las organizaciones portuguesas pertenecientes al sector público y privado. Para comprobar empíricamente las hipótesis de investigación formuladas hemos recurrido a los datos obtenidos mediante la aplicación de un cuestionario postal a 591 organizaciones públicas y 549 organizaciones privadas portuguesas, con una tasa de respuesta total del 31,3%. Los resultados obtenidos indican la asociación entre el conocimiento CMI y el grado de formación de los empleados, así como entre la implementación del CMI y la realización de cursos de formación. Por otro lado, no hemos obtenido evidencia empírica respecto a la posible relación entre la implementación del CMI y el grado de comunicación interna, el recurso a consultores externos, cuestiones de “modas de gestión” y la búsqueda de legitimidad.