Browsing by Issue Date, starting with "2004"
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- Comparison of a 10 week resistance strength training program, in muscle morphology, electromyography activity and strength gains on prepubescent girls and boysPublication . Monteiro, A.M.; Lopes, Vitor P.; Faro, AnaThe mechanisms that are behind the strength gains, in strength training programs, are not still well evidenced. It seems to exist the certainty that strength training produces greater gains, during puberty and after, in virtue, over all, of the increase of serum testosterone, which allows an increase of muscle hypertrophy. Strength gains gotten before puberty, will be resultant of neurological adaptations, such as, the improvement of inter and intra-muscle coordination and order, the synchronization, the amount of motor units recruited, and the frequency of nervous stimulus, and not so much due to hypertrophy. The purpose of this research was to compare the maximal voluntary isometric force (MVIF), the electromyography activity (EMG) and the muscle thickness between pre-pubertal boys and girls. The results suggested that prepubescent children can increase strength following a strength training program that includes callisthenic exercises. There were no significant differences on the MVIF between boys and girls doing the triceps press exercise. The strength gains were not followed by an increase of muscle mass. In the same way, there were no significant differences according to gender on the thickness of the triceps of the both arm of the triceps. It seems that the elements underlying the increase and strength gains can be related to the increase of the coordination of the movement. The coordination seems to be an element that highly contributes to the increase of strength for more complex exercises.
- The effect of residual stresses in the lateral-torsional buckling of steel I-beams at elevated temperaturePublication . Vila Real, Paulo M.M.; Cazeli, Ronisi; Silva, Luís Simões; Piloto, P.A.G.When a beam is bent about its greatest flexural resistance axis it may twist and move laterally, before it reaches its strength limit in bending. Although this problem of lateral-torsional buckling of steel beams at room temperature has well established solution, the same problem at elevated temperature has not. The lateral-torsional buckling of steel I- beams have been numerically investigated from room temperature up to 700 °C, with the aim of assessing the effects of the residual stresses in this mechanism of failure. A geometrically and materially non-linear finite element program i.e., a general model, has been used to determine the lateral-torsional resistance of steel 1-beams at elevated temperatures, according to the same material properties of Eurocode 3, Pan 1-2. The numerical results have been compared to the results of the simple model presented in Eurocode 3, Part 1-2 (1995) and to a new proposal that is being considered for approval.
- The effect of site preparation intensity on root development, mortality and growth, in Castanea sativa and Pseudotsuga menziesii species of young forest plantationsPublication . Fonseca, Felícia; Figueiredo, Tomás de; Guerra, Alzira; Martins, AfonsoIn Portuguese conditions, the productivity of most soils used for forest plantations is limited by low root support, low available water volume and low nutrient availability. This requires soil preparation operations before planting, using more or less intense tillage in order to decrease those limitations. However, there is a lack of information concerning the effect of those operations on soil properties and plant behaviour. In order to improve the knowledge about this subject, a study is conducted supported by an experimental field established near Bragança, NE Portugal. This field was established in 2001, at 700 m height, mean annual rainfall 1000 mm, mean annual temperature 12oC and Mediterranean climate conditions, consisting of six treatments, randomly distributed, in plots with 375 m2 area and comprising three blocks, each one in different topographic positions (near flat plateau, gentle slope shoulder, steep mid-slope). Pseudotsuga menziesii (PM) and Castanea sativa (CS), were used as forest species, on 4 2 m density and separated lines (2 for PM and 2 for CS), with 12 plants on each line by plot. The following treatments were applied: (a) No tillage and hole plantation with hole digger (SMPC); (b) Continuous subsoil mobilisation, using a covering shovel and plantation in the furrow (RCAV); (c) No previous subsoil mobilisation with furrow-hillock surface soil with two plough passes and plantation in the hillock side (SRVC); (d) Located subsoil mobilisation, followed by two plough passes, leaving furrow-hillock surface soil and plantation as in (c) (RLVC); (e) Continuous subsoil mobilisation, followed by two plough passes, leaving furrow-hillock surface soil and plantation as in (c) (RCVC); (f) Continuous subsoil mobilisation followed by continuous plough and plantation in the furrow (RCLC). The deepness and density of root system, mortality after plantation, before summer period and after that and growth (height and diameter) during the two first years, were quantified on both planted species. The obtained results shows: (i) root density is higher on PM at 10-20 cm depth while CS shows a deeper rooting system with higher density at 20-30 cm depth and higher soil volume exploited, especially on more intense treatments; (ii) after plantation and before summer period the highest mortality was observed on the lowest intensity treatments (SMPC and RCAV), and also on the highest intensity treatment (RCLC); (iii) after summer, the higher mortality was also observed on the lowest intensity treatments, while the lower values were detected on the intermediate treatments (SRVC and RLVC); (iv) plant growth (height and diameter) is similar in the different treatments, but, growth, when expressed as absolute value, is higher on PM than on CS, and, when expressed as relative increments in plant diameter, is higher in CS than in PM and always higher during the second year after plantation.
- As Inter-relações turismo, meio ambiente e culturaPublication . Pires, Eliane Cristine RaabDiante de uma crescente preocupação com os impactos negativos no meio ambiente e nas comunidades locais, causados tanto pelo desenvolvimento de forma geral, quanto pela actual dimensão e características da actividade do turismo de forma particular, mostra-se mais do que urgente a necessidade de reflexões (e acções) que viabilizem a superação da actual problemática ambiental, que vem afectando, sobremaneira, a qualidade de vida humana em seu sentido mais amplo. O presente estudo tem por finalidade subsidiar os alunos do curso de turismo com elementos de referência sobre a estreita ligação entre turismo, meio ambiente e cultura, favorecendo um melhor entendimento sobre a complexidade dessas relações estabelecidas e uma reflexão sobre o desafio contido na recente busca do turismo sustentável como forma preventiva e, até mesmo, correctiva de problemas ambientais. Este trabalho é dividido, por questões didácticas, em três partes. A primeira parte, de carácter introdutório, tece algumas considerações sobre a significativa expansão do turismo convencional ou de massa como actividade de crescente inserção na vida das sociedades; os conceitos básicos e uma breve história desde os primórdios do turismo até aos nossos dias, subdividida em três períodos: das origens até ao século XVIII, o turismo moderno do século XIX e início do século XX, e o turismo contemporâneo do século XX (após 1945). A segunda parte descreve o papel que o turismo assume, especialmente como campo de acções humanas, oferecendo um rico e complexo locus de relações interpessoais e de relação das pessoas com lugares e com culturas, enfatizando, por conseguinte, a possibilidade do desenvolvimento sustentável a partir da análise dos efeitos negativos da actividade turística. E, por fim, a conclusão que precipuamente visa expressar uma opinião pessoal decorrente de todo o trabalho de pesquisa, neste caso em particular, também conduz a um prognóstico factível e pragmático para o terceiro milénio. In view of a growing concern about the negative environmental impacts on the ecosystem and on the local communities, caused by the development of tourism in general sense, and by its present dimension and characteristics in a particular way, it is necessary to reflect and take actions enabling people to overcome the environmental issues that has been affecting, excessively, the quality of human life in its broader sense. The purpose of the present study is to provide the students of the tourism course with references on the inter-relations of tourism with the environment and culture, a better understanding towards the complexity of these relationships as well as a reflection on the challenge in the recent search of a sustainable tourism as a preventive and, at the same time, corrective measure of the environmental problems. This study is divided, for didactic reasons, into three parts. The first part, of introductory aspect, gives some general remarks on the significant expansion of the mass tourism as an activity of increasing insertion in the life of the societies; the basic concepts and a short history from the beginning of tourism to the present, subdivided into three periods: from the origins to the 18th century; modern tourism of the 19th century and the beginning of the 20th century; the contemporary tourism of the 20th century (after 1945). The second part focuses on the role of tourism, especially as a field of human actions, offering a rich and complex locus of interpersonal relations and the relation between people, places and cultures, emphasizing, therefore, the possibility of a sustainable development from the analysis of the negative effects of the tourist activity. And, finally, the conclusion which essentially aims to express a personal opinion as a result of the investigation in this particular case, also leads to a feasible and pragmatic prognostic for the third millennium. Devant la croissante préoccupation face aux impacts négatives dans l’environnement et dans les communautés locales, causés autant par le développement en général, que par l’actuelle dimension et les caractéristiques de l’activité du tourisme en particulier, il se montre plus qu’urgent le besoin de réflexions (et d’actions) qui rendent possible le dépassement de l’actuelle problématique de l’environnement, qui affecte, affectant, excessivement, la qualité de vie humaine dans son sens large. La présente étude a pour finalité de subventionner les élèves du cours de tourisme avec des éléments de référence sur l’étroite liaison entre le tourisme, l’environnement et la culture, en favorisant une meilleure compréhension de la complexité de ces relations établies et à une réflexion sur le défi contenu dans la récente recherché du tourisme soutenable comme une forme préventive et, voir même, corrective de problèmes d’environnement. Ce travail est divisé, pour des questions didactiques, en trios parties. La première partie, à caractère introducteur, tisse quelques considérations sur la significative expansion du tourisme de masse comme activité d’insertion croissante dans la vie des sociétés ; les concepts basiques et une brève histoire depuis les débuts du tourisme jusqu’à nos jours, qui se divise elle-même en trois périodes: des origines jusqu’au XVIII siècle; le tourisme moderne du XIX siècle et le commencement du XX siècle; le tourisme contemporain du XX siècle (après 1945). La seconde partie décrit le rôle que le tourisme assume, surtout comme champ d’actions humaines, offrant un riche et complexe locus de relations inter-personnelles et de relations des personnes avec des lieus et la culture, en soulignant, par conséquent, la possibilité du développement soutenable à partir de l’analyse des effets négatifs de l’activité touristique. Et, finalement, la conclusion qui cherche principalement à exprimer un avis personnel lié à tout le travail de recherche, dans ce cas particulier, conduit aussi à un pronostic possible et pragmatique pour le troisième millénaire.
- Experimental modal analysis of a synthetic composite femurPublication . Rodrigues, J.F.D.; Lopes, Hernani; Melo, F.J.M.Q. de; Simões, J.A.In this paper we describe the experimental characterization of the modal parameters of asynthetic com- posite femur model widely used in biomechanical research studies.The objective of the experimental procedure was to identify the natural frequencies and modes hapes of anun- constrained (free–free) femur.
- Epoxidation of 2-Styrylchromone derivativesPublication . Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José; Patonay, Támas; Lévai, Albert2-Styrylchromones constitute a small group of natural heterocyclic compounds with significant biological properties. Certain natural and synthetic hydroxyl derivatives have shown important pharmacological and mainly antioxidant activities [1 ,2]. We are interested in the design of new 2-styrylchromones analogues containing hydroxyl groups at C-3 and in the Ca=C~ systems because they could increase the antioxidation activity of these type of compounds [2]. Our first approach is the preparation of epoxy systems and then we will try to open the epoxy ring to give the desired hydroxyl derivatives. We studied the epoxidation of 2-styryl-chromones 1 with hydrogen peroxide and iodosylbenzene using [salen Mn(lll)] as catalyst, and the epoxy products 2 were obtained in moderate yields. Since the best results were obtained with iodosylbenzene, we applied oxidant to compounds 3 in order to prepare 4. In this communication, we will report the synthetic details and the structural characterisation of the epoxides 3 and 4.
- The plant communities of the Rumici indurati-Dianthion lusitani alliance in the Lusitan Duriensean biogeographical sector (NE Portugal and CW Spain).Publication . Bernardos, Sónia; Crespí, António; Aguiar, Carlos; Fernández Diez, Javier; Amich, FranciscoLa vegetación rupícola de la alianza Rumici indurati-Dianthion lusitani en el centro oeste (CW) de la Península Ibérica es analizada utilizando los métodos de la Escuela de Zürich-Montpellier. Tablas fitosociológicas, y datos biogeográficos, ecológicos y florísticos son presentados aquí para esta alianza. Se describen dos nuevos sintáxones: Rumici indurati-Anarrhinetum durimini y Phagnalo saxatilis-Antirrhinetum lopesianii. Por último, y utilizando análisis numéricos, se comparan estas fitocenosis Lusitan Duriensean con las presentes en otros sectores biogeográficos peninsulares.
- Crónica de uma profissão mal amadaPublication . Mesquita, CristinaO calendário marcava o mês de Julho do ano de 1989. O ambiente era de festa, de orgulho e de expectativa. Ana, contente com o trabalho que havia desenvolvido ao longo dos três anos de formação, pensava no dia em que iria exercer funções como educadora de infância. Tinha já antecipadamente feito algumas opções queria ser educadora de infância da rede pública. Sabia que os caminhos poderiam ser sinuosos, mas estava decidida. A rede pública afigurava-se-lhe como mais justa e menos segregadora.
- The role of foundational ontologies in manufacturing domain applicationsPublication . Borgo, Stefano; Leitão, PauloAlthough ontology has gained wide attention in the area of information systems, a criticism typical of the early days is still rehearsed here and there. Roughly, this criticism says: general ontologies are not suited for real applications. We believe this is the result of a misunderstanding of the role of general ontologies since, we claim, even foundational ontologies (the most general and formal ontologies) have a crucial role in building reusable, adaptable and transparent application systems. We support this view by showing how foundational ontologies can be used in the manufacturing control area. Our approach (partially presented here through an example) provides a domain specific ontology which is explicitly designed for applications, theoretically organized by a foundational ontology, driven by the application field for all intents and purposes, suitable for communication across different applications.
- Activity coefficient and solubility of amino acids in water by the modified Wilson modelPublication . Xin, Xu; Pinho, Simão; Macedo, Eugénia A.The modified Wilson model for the phase behavior of polymer aqueous solutions has been applied to calculate activity coefficients and the solubility of amino acids and small peptides in aqueous solutions. The interaction parameters estimated from the activity coefficients and the solubility data are used to evaluate the solubility of amino acids. The model can accurately represent the activity coefficients of amino acids with only two adjustable parameters per system. It is also used to describe the solubility of several amino acids with satisfactory results. After introduction of the influence of temperature on the energy parameters, it is possible to obtain better predictions of the solubility at higher temperatures than those from UNIFAC and UNIQUAC. The results achieved for the solubility of a mixture of two amino acids are in good agreement with the literature data.