Temperature fields in a channel partially filled with a porous material under local thermal non-equilibrium condition-an exact solution

This work examines analytically the forced convection in a channel partially filled with a porous material and subjected to constant wall heat flux. The Darcy–Brinkman–Forchheimer model is used to represent the fluid transport through the porous material. The local thermal non-equilibrium, two-equation model is further employed as the solid and fluid heat transport equations. Two fundamental models (models A and B) represent the thermal boundary conditions at the interface between the porous medium and the clear region. The governing equations of the problem are manipulated, and for each interface model, exact solutions, for the solid and fluid temperature fields, are developed. These solutions incorporate the porous material thickness, Biot number, fluid to solid thermal conductivity ratio and Darcy number as parameters. The results can be readily used to validate numerical simulations. They are, further, applicable to the analysis of enhanced heat transfer, using porous materials, in heat exchangers.

Ion-acoustic envelope modes in a degenerate relativistic electron-ion plasma

A self-consistent relativistic two-fluid model is proposed for one-dimensional electron-ion plasma dynamics. A multiple scales perturbation technique is employed, leading to an evolution equation for the wave envelope, in the form of a nonlinear Schrödinger type equation (NLSE). The inclusion of relativistic effects is shown to introduce density-dependent factors, not present in the non-relativistic case - in the conditions for modulational instability. The role of relativistic effects on the linear dispersion laws and on envelope soliton solutions of the NLSE is discussed.

Méthodes de Bootstrap pour les modèles à facteurs

Cette thèse développe des méthodes bootstrap pour les modèles à facteurs qui sont couram- ment utilisés pour générer des prévisions depuis l'article pionnier de Stock et Watson (2002) sur les indices de diffusion. Ces modèles tolèrent l'inclusion d'un grand nombre de variables macroéconomiques et financières comme prédicteurs, une caractéristique utile pour inclure di- verses informations disponibles aux agents économiques. Ma thèse propose donc des outils éco- nométriques qui améliorent l'inférence dans les modèles à facteurs utilisant des facteurs latents extraits d'un large panel de prédicteurs observés. Il est subdivisé en trois chapitres complémen- taires dont les deux premiers en collaboration avec Sílvia Gonçalves et Benoit Perron. Dans le premier article, nous étudions comment les méthodes bootstrap peuvent être utilisées pour faire de l'inférence dans les modèles de prévision pour un horizon de h périodes dans le futur. Pour ce faire, il examine l'inférence bootstrap dans un contexte de régression augmentée de facteurs où les erreurs pourraient être autocorrélées. Il généralise les résultats de Gonçalves et Perron (2014) et propose puis justifie deux approches basées sur les résidus : le block wild bootstrap et le dependent wild bootstrap. Nos simulations montrent une amélioration des taux de couverture des intervalles de confiance des coefficients estimés en utilisant ces approches comparativement à la théorie asymptotique et au wild bootstrap en présence de corrélation sérielle dans les erreurs de régression. Le deuxième chapitre propose des méthodes bootstrap pour la construction des intervalles de prévision permettant de relâcher l'hypothèse de normalité des innovations. Nous y propo- sons des intervalles de prédiction bootstrap pour une observation h périodes dans le futur et sa moyenne conditionnelle. Nous supposons que ces prévisions sont faites en utilisant un ensemble de facteurs extraits d'un large panel de variables. Parce que nous traitons ces facteurs comme latents, nos prévisions dépendent à la fois des facteurs estimés et les coefficients de régres- sion estimés. Sous des conditions de régularité, Bai et Ng (2006) ont proposé la construction d'intervalles asymptotiques sous l'hypothèse de Gaussianité des innovations. Le bootstrap nous permet de relâcher cette hypothèse et de construire des intervalles de prédiction valides sous des hypothèses plus générales. En outre, même en supposant la Gaussianité, le bootstrap conduit à des intervalles plus précis dans les cas où la dimension transversale est relativement faible car il prend en considération le biais de l'estimateur des moindres carrés ordinaires comme le montre une étude récente de Gonçalves et Perron (2014). Dans le troisième chapitre, nous suggérons des procédures de sélection convergentes pour les regressions augmentées de facteurs en échantillons finis. Nous démontrons premièrement que la méthode de validation croisée usuelle est non-convergente mais que sa généralisation, la validation croisée «leave-d-out» sélectionne le plus petit ensemble de facteurs estimés pour l'espace généré par les vraies facteurs. Le deuxième critère dont nous montrons également la validité généralise l'approximation bootstrap de Shao (1996) pour les regressions augmentées de facteurs. Les simulations montrent une amélioration de la probabilité de sélectionner par- cimonieusement les facteurs estimés comparativement aux méthodes de sélection disponibles. L'application empirique revisite la relation entre les facteurs macroéconomiques et financiers, et l'excès de rendement sur le marché boursier américain. Parmi les facteurs estimés à partir d'un large panel de données macroéconomiques et financières des États Unis, les facteurs fortement correlés aux écarts de taux d'intérêt et les facteurs de Fama-French ont un bon pouvoir prédictif pour les excès de rendement.

Estudo Preliminar das Propriedades Psicométricas do Inventário de Lateralidade de Edinburgh numa Amostra de Adultos da População Portuguesa

Introdução: A lateralidade é a diferença na capacidade de controlo entre os dois lados do corpo. Os métodos utilizados para avaliar a lateralidade manual incluem a observação efetiva do uso do membro dominante ou a aplicação de inventários respondidos pelo próprio indivíduo avaliado. O Inventário de Lateralidade de Edinburgh (EHI) é o instrumento mais utilizado para avaliar a lateralidade manual. Apesar do seu uso amplo, em Portugal não existem estudos que avaliem a sua validade e fidedignidade. Objetivos: Estudar as propriedades psicométricas do Inventário de Lateralidade de Edinburgh numa amostra da população portuguesa. Métodos: A amostra é constituída por 290 pessoas (135 homens e 155 mulheres), com idades compreendidas entre os 18 e os 65 anos. Todos os participantes preencheram uma declaração de consentimento informado e uma bateria de testes neuropsicológicos Resultados: A média no EHI foi de 62,36 (DP = 38,00). Os resultados demonstraram que das seis variáveis sociodemográficas (idade, sexo, escolaridade, zona de residência, regiões e profissão) três apresentaram ter influência significativa nas pontuações do EHI: idade, zona de residência e regiões. A confiabilidade e a estabilidade temporal do EHI apresentaram resultados adequados. A análise fatorial confirmatória mostrou que o modelo não é melhor explicado por um fator. Para dois fatores o modelo continua a não ser adequado. Conclusão: Apesar de termos obtido uma boa consistência interna não nos é possível considerar este teste como o mais adequado para medir o constructo da lateralidade. / Introduction: The handedness is the difference in the control capacity between the two sides of the body. The methods used to evaluate the manual handedness include the effective observation of the use of dominant member or application of inventories answered by the person assessed. The Edinburgh Handedness Inventory (EHI) is the most used to evaluate manual handedness. Even though being widely used, in Portugal there are no studies that measure its validity and reliability. Objective: To study the psychometric properties of Edinburgh Handedness Inventory in a Portuguese sample. Methods: The sample consists of 290 people (135 men and 155 women), aged between 18 and 65 years. All participants filled an informed consent form and a battery of neuropsychological tests. Results: The average in EHI was 62.36 (SD = 38.00). The results showed that 3 of 6 sociodemographic variables showed significant influence in EHI scores. The reliability and temporal stability of EHI were adequate. Confirmatory factor analysis showed that the model is not better explained by one factor. A two-factor model was not also suitable. Conclusion: Even though we got a good internal consistency we cannot consider this test as the most appropriate for measuring the handedness construct.

Dynamic Simulation Methods for Evaluating Motor Vehicle and Roadway Design and Resolving Policy Issues, 1990

This study had three objectives: (1) to develop a comprehensive truck simulation that executes rapidly, has a modular program construction to allow variation of vehicle characteristics, and is able to realistically predict vehicle motion and the tire-road surface interaction forces; (2) to develop a model of doweled portland cement concrete pavement that can be used to determine slab deflection and stress at predetermined nodes, and that allows for the variation of traditional thickness design factors; and (3) to implement these two models on a work station with suitable menu driven modules so that both existing and proposed pavements can be evaluated with respect to design life, given specific characteristics of the heavy vehicles that will be using the facility. This report summarizes the work that has been performed during the first year of the study. Briefly, the following has been accomplished: A two dimensional model of a typical 3-S2 tractor-trailer combination was created. A finite element structural analysis program, ANSYS, was used to model the pavement. Computer runs have been performed varying the parameters defining both vehicle and road elements. The resulting time specific displacements for each node are plotted, and the displacement basin is generated for defined vehicles. Relative damage to the pavement can then be estimated. A damage function resulting from load replications must be assumed that will be reflected by further pavement deterioration. Comparison with actual damage on Interstate 80 will eventually allow verification of these procedures.

Estudo Preliminar das Propriedades Psicométricas e dos Dados Normativos da Forma Geral das Matrizes Progressivas de Raven numa Amostra da Comunidade

Objetivo: Estudar as propriedades psicométricas e os dados normativos da Forma Geral das Matrizes Progressivas de Raven numa amostra da comunidade da população portuguesa. Método: A amostra é constituída por 697 pessoas (314 homens e 383 mulheres), com idades compreendidas entre os 12 e os 90 anos. Todos os participantes preencheram uma declaração de consentimento informado e uma bateria de testes neuropsicológicos, incluindo a Forma Geral das Matrizes Progressivas de Raven (FG-MPR), Teste de Memória de 15-Item de Rey, Escala de Autoavaliação de Ansiedade de Zung, Bateria de Avaliação Frontal e Figura Complexa de Rey. Resultados: A média na FG-MPR foi de 44,47 (DP = 10,78). Os resultados demonstraram que todas as variáveis sociodemográficas (idade, sexo, escolaridade, profissão, regiões e tipologia de áreas urbanas), exceto o estado civil, apresentaram ter influência significativa nas pontuações da FG-MPR. A confiabilidade e a estabilidade temporal da FG-MPR revelaram-se adequadas. A análise fatorial exploratória e confirmatória mostrou que o modelo para um fator não é adequado. Um modelo a quatro fatores continua a não ser adequado. Conclusão: Os dados do presente estudo sugerem que se trata de um instrumento com potencialidades na sua utilização junto da população portuguesa. / Purpose: To study the psychometric properties and date normative of the Raven’s Standard Progressive Matrices in a Portuguese community sample. Method: The sample consists of 697 people (314 men and 383 women), aged between 12 and 90 years. All participants filled an informed consent form and a battery of neuropsychological tests, which included Raven’s Standard Progressive Matrices (RSPM), Rey 15-Item Memory Test, Zung Self-Rating Anxiety Scale, Frontal Assessment Battery, and Rey Complex Figure Test. Results: The average in RSPM was 44.47 (SD = 10.78). The results showed that all of the sociodemographic variables (age, sex, education, profession, region, and typology of urban areas), with the exception of civil status, showed significant influence on RSPM scores. The reliability and temporal stability of RSPM were adequate. Exploratory and Confirmatory factor analysis showed that the model is not better explained by one factor. A two-factor model was not also suitable. Conclusion: The data from this study suggest that it is an instrument with potential for its use among the Portuguese population.

Entscheidungsstrukturen für Bildungsfragen in offenen Gesellschaften

Können offene Gesellschaften, die über eine bestimmte Staatsideologie nicht verfügen, sondern unterschiedliche Interessen organisieren, Ziele für ein öffentliches Bildungssystem überhaupt begründen? Nachdem die fraglose Eingliederung des Bildungswesens in die Staatsverwaltung nicht mehr legitim erscheint und nachdem sich eine Organisation nach dem Demokratieprinzip als fragwürdig erwiesen hat, ist zunehmend von vertraglichen Regelungen auch im Bildungswesen die Rede, von Marktmechanismen oder korporativistischen Prinzipien. Privatisierung ist dafür das falsche Stichwort, es scheint eher um die vertragliche Organisation öffentlichen Handelns zu gehen. Die neuere bildungspolitische Entwicklung geht in diese Richtung: De-Institutionalisierung, Effizienzerwartung, Multikulturalität, Wahlfreiheit, Beteiligung. (DIPF/Orig.)

Anatomy in the Library: Anatomical Models on Course Reserves

In Fall 2015, the Engineering and Physical Science Library (EPSL) began lending anatomical models as part of its course reserves program. EPSL received a partial skeleton and two muscle model figures from instructors of BSCI105. These models circulate for 4 hours at a time and are generally used by small, collaborative groups of students in the library. This poster will look at the challenges and rewards for adding these items to EPSL’s course reserves.

410 - Phase transitions induced by coloured voltage noise in nerve membranes

Quantitative conditions are derived under which electrically excitable membranes can undergo a phase transition induced by an externally applied voltage noise. The results obtained for a non-cooperative and a cooperative form of the two-state model are compared. © 1981.

Using a voxel-based krogh cylinder array to simulate microvascular contrast enhancement

The goal of this study is to better simulate microscopic and voxel-based dynamic contrast enhancement in magnetic resonance imaging. Specifically, errors imposed by the traditional two-compartment model are reduced by introducing a novel Krogh cylinder network. The two-compartment model was developed for macroscopic pharmacokinetic analysis of dynamic contrast enhancement and generalizing it to voxel dimensions, due to the significant decrease in scale, imposes physiologically unrealistic assumptions. In the project, a system of microscopic exchange between plasma and extravascular-extracellular space is built while numerically simulating the local contrast agent flow between and inside image elements. To do this, tissue parameter maps were created, contrast agent was introduced to the tissue via a flow lattice, and various data sets were simulated. The effects of sources, tissue heterogeneity, and the contribution of individual tissue parameters to an image are modeled. Further, the study attempts to demonstrate the effects of a priori flow maps on image contrast, indicating that flow data is as important as permeability data when analyzing tumor contrast enhancement. In addition, the simulations indicate that it may be possible to obtain tumor-type diagnostic information by acquiring both flow and permeability data.

Literacia em diabetes nos alunos do ensino superior público do concelho de Mirandela

A literacia em diabetes parece ser uma das ferramentas fundamentais para combater o aumento de prevalência desta patologia crónica que tem crescido exponencialmente ao longo dos anos quer a nível mundial, quer a nível nacional. Com este estudo pretendeu-se avaliar o nível de literacia em diabetes nos estudantes do ensino superior público do concelho de Mirandela, para, em consequência, fornecer algumas diretrizes para a proposta de um projeto de intervenção nesta comunidade. Teve como objetivos específicos: validar o questionário dos conhecimentos da Diabetes (QCD); relacionar os níveis de conhecimento sobre diabetes com as variáveis sociodemográficas e clinicas. A amostra estudada compreende 432 alunos do ensino superior público do concelho de Mirandela que reponderam ao questionário no período de 15 de fevereiro a 18 de março de 2016. Verificou-se que a aplicação do questionário dos conhecimentos da diabetes (QCD; Sousa & McIntyre, 2003) que avalia os conhecimentos das pessoas acerca da diabetes e seu tratamento, parece ser aceitável na população em geral e o modelo bidimensional obtido com a análise fatorial confirmatória revelou bons índices de ajustamento. Os resultados indicaram um reduzido nível de literacia em diabetes na amostra de participantes e o seu desconhecimento está associado a mitos e falsos conceitos mais do que a incerteza; que o conhecimento na dimensão duração da doença era maior que na dimensão conhecimento global da diabetes (causas, controlo, tratamento e complicações); os alunos mais novos possuem mais conhecimento sobre a diabetes, o género feminino parece revelar maior conhecimento do que o masculino, que os alunos que residem no concelho de Mirandela apresentam menor conhecimento do que os restantes e que os alunos que possuem e residem com familiares com diabetes possuem mais conhecimento do que os outros, embora apresentem igualmente elevado desconhecimento por mitos e falsos conceitos. Conclui-se que existe uma necessidade de aposta em projetos educacionais comunitários para aumentar a literacia em diabetes.

Coordinated pricing and inventory management

This dissertation mainly focuses on coordinated pricing and inventory management problems, where the related background is provided in Chapter 1. Several periodic-review models are then discussed in Chapters 2,3,4 and 5, respectively. Chapter 2 analyzes a deterministic single-product model, where a price adjustment cost incurs if the current selling price is changed from the previous period. We develop exact algorithms for the problem under different conditions and find out that computation complexity varies significantly associated with the cost structure. %Moreover, our numerical study indicates that dynamic pricing strategies may outperform static pricing strategies even when price adjustment cost accounts for a significant portion of the total profit. Chapter 3 develops a single-product model in which demand of a period depends not only on the current selling price but also on past prices through the so-called reference price. Strongly polynomial time algorithms are designed for the case without no fixed ordering cost, and a heuristic is proposed for the general case together with an error bound estimation. Moreover, our illustrates through numerical studies that incorporating reference price effect into coordinated pricing and inventory models can have a significant impact on firms' profits. Chapter 4 discusses the stochastic version of the model in Chapter 3 when customers are loss averse. It extends the associated results developed in literature and proves that the reference price dependent base-stock policy is proved to be optimal under a certain conditions. Instead of dealing with specific problems, Chapter 5 establishes the preservation of supermodularity in a class of optimization problems. This property and its extensions include several existing results in the literature as special cases, and provide powerful tools as we illustrate their applications to several operations problems: the stochastic two-product model with cross-price effects, the two-stage inventory control model, and the self-financing model.

Méthodes de Bootstrap pour les modèles à facteurs

Cette thèse développe des méthodes bootstrap pour les modèles à facteurs qui sont couram- ment utilisés pour générer des prévisions depuis l'article pionnier de Stock et Watson (2002) sur les indices de diffusion. Ces modèles tolèrent l'inclusion d'un grand nombre de variables macroéconomiques et financières comme prédicteurs, une caractéristique utile pour inclure di- verses informations disponibles aux agents économiques. Ma thèse propose donc des outils éco- nométriques qui améliorent l'inférence dans les modèles à facteurs utilisant des facteurs latents extraits d'un large panel de prédicteurs observés. Il est subdivisé en trois chapitres complémen- taires dont les deux premiers en collaboration avec Sílvia Gonçalves et Benoit Perron. Dans le premier article, nous étudions comment les méthodes bootstrap peuvent être utilisées pour faire de l'inférence dans les modèles de prévision pour un horizon de h périodes dans le futur. Pour ce faire, il examine l'inférence bootstrap dans un contexte de régression augmentée de facteurs où les erreurs pourraient être autocorrélées. Il généralise les résultats de Gonçalves et Perron (2014) et propose puis justifie deux approches basées sur les résidus : le block wild bootstrap et le dependent wild bootstrap. Nos simulations montrent une amélioration des taux de couverture des intervalles de confiance des coefficients estimés en utilisant ces approches comparativement à la théorie asymptotique et au wild bootstrap en présence de corrélation sérielle dans les erreurs de régression. Le deuxième chapitre propose des méthodes bootstrap pour la construction des intervalles de prévision permettant de relâcher l'hypothèse de normalité des innovations. Nous y propo- sons des intervalles de prédiction bootstrap pour une observation h périodes dans le futur et sa moyenne conditionnelle. Nous supposons que ces prévisions sont faites en utilisant un ensemble de facteurs extraits d'un large panel de variables. Parce que nous traitons ces facteurs comme latents, nos prévisions dépendent à la fois des facteurs estimés et les coefficients de régres- sion estimés. Sous des conditions de régularité, Bai et Ng (2006) ont proposé la construction d'intervalles asymptotiques sous l'hypothèse de Gaussianité des innovations. Le bootstrap nous permet de relâcher cette hypothèse et de construire des intervalles de prédiction valides sous des hypothèses plus générales. En outre, même en supposant la Gaussianité, le bootstrap conduit à des intervalles plus précis dans les cas où la dimension transversale est relativement faible car il prend en considération le biais de l'estimateur des moindres carrés ordinaires comme le montre une étude récente de Gonçalves et Perron (2014). Dans le troisième chapitre, nous suggérons des procédures de sélection convergentes pour les regressions augmentées de facteurs en échantillons finis. Nous démontrons premièrement que la méthode de validation croisée usuelle est non-convergente mais que sa généralisation, la validation croisée «leave-d-out» sélectionne le plus petit ensemble de facteurs estimés pour l'espace généré par les vraies facteurs. Le deuxième critère dont nous montrons également la validité généralise l'approximation bootstrap de Shao (1996) pour les regressions augmentées de facteurs. Les simulations montrent une amélioration de la probabilité de sélectionner par- cimonieusement les facteurs estimés comparativement aux méthodes de sélection disponibles. L'application empirique revisite la relation entre les facteurs macroéconomiques et financiers, et l'excès de rendement sur le marché boursier américain. Parmi les facteurs estimés à partir d'un large panel de données macroéconomiques et financières des États Unis, les facteurs fortement correlés aux écarts de taux d'intérêt et les facteurs de Fama-French ont un bon pouvoir prédictif pour les excès de rendement.

Deviant behavior variety scale: Development and validation with a sample of portuguese adolescents

This study presents the development and analysis of the psychometric properties of the Deviant Behavior Variety Scale (DBVS). Participants were 861 Portuguese adolescents (54 % female), aged between 12 and 19 years old. Two alternative models were tested using Confirmatory Factor Analysis. Although both models showed good fit indexes, the two-factor model didn’t presented discriminant validity. Further results provided evidence for the factorial and the convergent validity of the single-factor structure of the DVBS, which has also shown good internal consistency. Criterion validity was evaluated through the association with related variables, such as age and school failure, as well as the scale’s ability to capture group differences, namely between genders and school retentions, and finally by comparing a sub-group of convicted adolescents with a group of non-convicted ones regarding their engagement in delinquent activities. Overall, the scale presented good psychometric properties, with results supporting that the DBVS is a valid and reliable self-reported measure to evaluate adolescents’ involvement in deviance.

mRNA-Seq and microarray development for the Grooved carpet shell clam, Ruditapes decussatus: a functional approach to unravel host -parasite interaction

Background The Grooved Carpet shell clam Ruditapes decussatus is the autochthonous European clam and the most appreciated from a gastronomic and economic point of view. The production is in decline due to several factors such as Perkinsiosis and habitat invasion and competition by the introduced exotic species, the manila clam Ruditapes philippinarum. After we sequenced R. decussatus transcriptome we have designed an oligo microarray capable of contributing to provide some clues on molecular response of the clam to Perkinsiosis. Results A database consisting of 41,119 unique transcripts was constructed, of which 12,479 (30.3%) were annotated by similarity. An oligo-DNA microarray platform was then designed and applied to profile gene expression in R. decussatus heavily infected by Perkinsus olseni. Functional annotation of differentially expressed genes between those two conditionswas performed by gene set enrichment analysis. As expected, microarrays unveil genes related with stress/infectious agents such as hydrolases, proteases and others. The extensive role of innate immune system was also analyzed and effect of parasitosis upon expression of important molecules such as lectins reviewed. Conclusions This study represents a first attempt to characterize Ruditapes decussatus transcriptome, an important marine resource for the European aquaculture. The trancriptome sequencing and consequent annotation will increase the available tools and resources for this specie, introducing the possibility of high throughput experiments such as microarrays analysis. In this specific case microarray approach was used to unveil some important aspects of host-parasite interaction between the Carpet shell clam and Perkinsus, two non-model species, highlighting some genes associated with this interaction. Ample information was obtained to identify biological processes significantly enriched among differentially expressed genes in Perkinsus infected versus non-infected gills. An overview on the genes related with the immune system on R. decussatus transcriptome is also reported.