Binary sequences with prescribed autocorrelations

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Effects of Motor Observation Supplementation on Quadriceps Muscle Activity and Torque Production during Isokinetic Resistance Exercise

Many studies have analysed the influence of verbal instructions and attentional focus on the performance of various motor tasks. Moreover, research has also shown that humans display a wide network of mirror-neurons and that motor observation can promote increased motor- system excitability. The purpose of this study was to explore the combined effects of motor observation and internally focused verbal instructions on skeletal muscle activity, torque production and other related variables during an isokinetic resistance-exercise protocol. We hypothesized that the addition of motor observation to internally focused verbal instructions might enhance neural input to the knee-extensor muscles, ultimately leading to greater muscle activity and greater torque production during resistance exercise when compared to verbal instructions alone. We conducted a crossover design using two conditions: a control condition in which the participants received internally focused verbal instructions and an experimental condition including the same instructions, but supplemented with motor observation of the same exercise. Both groups performed 6 sets of 10 repetitions on an isokinetic dynamometer. Leg extension torque and EMG activity of the vastus mediallis, rectus femoris, vastus lateralis and bicep femoris was obtained. Results showed no statistically significant main effects for condition in peak torque (F = 0.343; p value = 0.573; Ꞃ2 = 0.037) nor surface electromyographic activity of the analysed muscles: vastus mediallis (F = 0.002; p value = 0.966; Ꞃ2 = <0.001), rectus femoris (F = 0.138; p-value = 0.718; Ꞃ2 = 0.015), vastus lateralis (F = 0.031; p value = 0.863; Ꞃ2 =0.003) or biceps femoris (F = 0.544; p value = 0.476; Ꞃ2 = 0.058). These results suggest that motor observation has no additional effect on torque production or muscle activity when compared to that seen with internally focused verbal instructions alone.Vários estudos têm analisado os efeitos da instrução verbal e de diferentes tipos de foco atencional ao nível do desempenho de diferentes tarefas motoras. Além disso, a literatura disponível também evidencia que os humanos possuem uma rede complexa de neurónios espelho e que a observação motora pode promover um aumento da excitabilidade cortical. O objetivo deste estudo foi analisar os efeitos combinados de observação motora e instrução verbal com foco atencional interno na ativação eletromiográfica do músculo esquelético, produção de torque e outras variáveis associadas na resposta a uma sessão de treino de força em regime isocinético. Estabeleceu-se a hipótese de que a suplementação da instrução verbal interna com a observação motora poderia aumentar o drive neural sobre os músculos extensores do joelho e assim potenciar uma maior atividade eletromiográfica e produção de torque quando comparada com utilização exclusiva da instrução verbal. Para testar esta hipótese recorreu-se a um desenho experimental cruzado com duas condições: uma condição de controlo que implicou instruções verbais com foco atencional interno e uma condição experimental que envolveu o mesmo tipo de instruções, mas ao qual foi adicionada a observação motora da tarefa a ser realizada durante a execução da mesma. Ambos os grupos realizaram 6 séries de 10 repetições num dinamómetro isocinético. Foram analisados o torque de extensão do joelho e EMG dos músculos vasto medial, reto femoral, vasto lateral e bicípite femoral. Não foram observados efeitos significativos para efeitos entre condições referentes aos valores de torque máximo (F = 0.343; p value = 0.573; Ꞃ2 = 0.037), ou de atividade eletromiográfica dos músculos analisados: vasto medial (F = 0.002; p value = 0.966; Ꞃ2 = <0.001), reto femoral (F = 0.138; p value = 0.718; Ꞃ2 = 0.015), vasto lateral (F = 0.031; p value = 0.863; Ꞃ2=0.003) ou bicípite femoral (F = 0.544; p value = 0.476; Ꞃ2 =0.058). Os resultados obtidos sugerem que a observação motora não promove qualquer efeito adicional sobre a produção máxima de torque ou de atividade eletromiográfica dos músculos envolvidos, quando comparada com utilização exclusiva de instruções verbais com foco atencional interno

Utilisation d'un modèle réduit expérimental comme référence pour la validation des modèles d'inondations en zone urbaine

Recent advances in flood modelling of urban areas have lead to the development of more sophisticated urban flood models. These models simulate flooding events by coupling the surface flow and the sewer system with an internal boundary condition (IBC). However, good quality data of flood events are hazardous to obtain. In this work we aim to present quality data (i.e. discharges and water levels at several locations) collected from an experimental scaled-model for enabling a benchmark test for urban flood models. In addition the IBC discharge coefficients provided herein are determined experimentally enabling a consistent validation of drainage models. The scaled model comprises of a rectangular surface-channel with a downstream weir discharge, and with six inlets with identical diameter. The experimental results indicate: (1) consistency between the discharges measured by the ADV/WRP and the volumetric method (2) consistency of the water levels obtained in each WRPs; (2) Good correlation between the inlet discharge coefficients, and the weir discharge coefficient (3) The centre inlets show a higher discharge than the side inlets and the downstream inlets show a higher discharge than the upstream ones.L’évolution actuelle de la modélisation des inondations urbaines a conduit au développement d´améliorations importantes des modèles d'inondations en milieu urbain. Ces modèles de programmation mathématique simulent des inondations en tenant compte de l'interaction entre l'écoulement de surface et l'écoulement dans le réseau d'assainissement. Toutefois, il est difficile d'obtenir des données de qualité sur ces inondations. Ce travail vise à présenter des données de qualité mesurées à l'échelle expérimentale (déversements et niveaux d’eau en divers points d'un canal), pour être utilisé comme test de référence et donc comme benchmark pour la validation des modèles d’inondations urbaines. De plus, les coefficients de déversement présentés sont calculés expérimentalement, permettant ainsi la validation des modèles d'assainissement. Le modèle à l'échelle est un canal rectangulaire avec renvoi du déversoir en aval et six arrivées de diamètre identique. Les résultats de l'expérience indiquent: (1) la cohérence entre les déversements mesurés par les sondes ADV/WRP et les résultats de la méthode volumétrique; (2) la cohérence des niveaux d'eau obtenus pour chaque sonde WRP; (3) une bonne corrélation entre le coefficient de déversement d’arrivée et le coefficient de déversement du déversoir en aval; (4) les arrivées au centre présentent des coefficients de déversement plus grands, de même que les arrivées en aval

Low density wood particleboards bonded with starch foam-study of production process conditions

It has been shown that wood particleboards bonded with sour cassava starch can display low density combined with good physico-mechanical performance, thanks to starch being able to produce a strong foam that fills the interparticular space. Here we optimize the pressing conditions for the production of these panels. The procedure involved hot-plate pressing in two stages: (1) lowering the top platen to a specified thickness for a duration designated as pressing time, followed by (2) raising the top platen to allow panel expansion for a duration designated as hold time. The parameters studied were the pressing time (10 to 150 s), the hold time (290 to 890 s), and the top platen temperature (80 to 190 degrees C). The hold time and pressing time showed to be crucial parameters. The best operating conditions corresponded to 600 s of press cycle time, comprising 60 s of pressing time and 540 s of hold time. The top platen temperature used was 190 degrees C. The particleboards produced had a density of 405 kgm(-3), an internal bond strength of 0.44 Nmm(-2), and a thickness swelling of 13.2%. This can be considered as very good performance, taking into account the panels' low density

A new methodology to evaluate the cure of resin-impregnated papers for HPL

High-pressure laminates (HPL) are a multipurpose, high strength and value-added surface material foruse on construction (facades, walls and flooring) and furniture sector. Standard HPL is obtained by thehot-pressing of an assembly of paper sheets impregnated with thermosetting resins (usually melamineformaldehydeand phenol-formaldehyde) and normally is used for surfacing wood based panels (WBP).In the last years the production of HPL has increased and new products are being launch, such as: HPLproduced with new resins, HPL with new functionalities (chemical resistance, wear resistance, UVresistance, etc.), compact HPL (high thickness).The introduction of new resins and the incorporation of additives increase the interest on thedevelopment of a novel methodology to evaluate the cure of the resin-impregnated paper makingpossible to optimise both the impregnation (resin content, speed, temperature) and the hot-pressing(time, temperature, pressure schedule) stages.Using ABES (Automated Bonding Evaluation System) equipment, a study on the curing conditions ofseveral resin-impregnated papers and its impact on the performance of HPL, has been carried out. Anew methodology is presented and applied to several different combinations of kraft, decorative andoverlay papers and wood, selected to ensure higher fidelity to a real HPL under hot-pressing conditions.A kinetic model for the cure of impregnated papers was developed and its relation with currentaccepted curing mechanism is presented

Sistemas de controle automático

O livro cobre modelagem, análise e projeto tanto de sistemas contínuos no tempo quanto de sistemas controlados por computador. É colocada ênfase na modelagem de sistemas físicos através de equações diferenciais ordinárias acopladas, uma vez que estas constituem o suporte de uma vasta classe de métodos de projeto de controladores. A base necessária para a utilização deste livro consiste no conhecimento elementar de equações diferenciais ordinárias e de física geral. A obra pode ser usada como livro-texto de um curso básico em controle automático, quer como manual de auto-estudo para profissionais em exercício

Internal and external costs of transport in Portugal

Urban dispersion (sprawl) is a reality, however unplanned it may be. Its supporters advocate contact with nature, space and intimacy; however, alleged disadvantages include land consumption, public infrastructure and mobility costs, and housing prices. The Research Project “Costs and Benefits of Urban Dispersion on a local scale” seeks to contribute to the debate with an objective approach based on the quantification of costs, externalities and benefits of different urban settlement patterns, thus “bringing urban form back to planning”. This paper presents one of the Project’s tasks, the one concerning mobility costs, both internal and external. Quantified internal costs include investment, inspection, insurance, energy and maintenance; external ones include accident and environmental costs, calculated for road and rail transport. Different methods are combined depending on available data sources in order to achieve figures for each of the cost components per vehicle-km, ton-km and passenger-km for 2005, at 2009 prices. Results show that internal costs are larger than external ones for the majority of motorized transport, except two-wheelers, and for rail. External costs are larger than internal ones for soft modes, mainly due to high accident costs. Cost components, both internal and external, related to fuel consumption are the most relevant in heavy modes’ cost structures. Investment costs are the most important category for the majority of the remaining modes. Results also stress that current occupancy rates, load factors and vehicle mileages hinder the economic efficiency of collective and two-wheeled modes of transportation and may contribute to the pervasiveness of cars in Portugal

FleXml: Plataforma de Ensino a Distância para Promover Flexibilidade Cognitiva

Esta comunicação apresenta a plataforma Web FleXml para ensino a distância, desenvolvida na Universidade do Minho, em Portugal, e estruturada segundo os princípios da Teoria de Flexibilidade Cognitiva. Começamos por caracterizar a referida teoria, passando de seguida a descrever a plataforma Web FleXml em termos da sua arquitectura e funcionamento nos módulos autor e leitor. Por fim, apresentamos as suas particularidades na implementação de um assunto a distância.Fundação para a Ciência e Tecnologia - POCTI/ 33691/CED/2000