4 resultados para reductions
em Instituto Politécnico do Porto, Portugal
Resumo:
This study addresses to the optimization of pultrusion manufacturing process from the energy-consumption point of view. The die heating system of external platen heaters commonly used in the pultrusion machines is one of the components that contribute the most to the high consumption of energy of pultrusion process. Hence, instead of the conventional multi-planar heaters, a new internal die heating system that leads to minor heat losses is proposed. The effect of the number and relative position of the embedded heaters along the die is also analysed towards the setting up of the optimum arrangement that minimizes both the energy rate and consumption. Simulation and optimization processes were greatly supported by Finite Element Analysis (FEA) and calibrated with basis on the temperature profile computed through thermography imaging techniques. The main outputs of this study allow to conclude that the use of embedded cylindrical resistances instead of external planar heaters leads to drastic reductions of both the power consumption and the warm-up periods of the die heating system. For the analysed die tool and process, savings on energy consumption up to 60% and warm-up period stages less than an half hour were attained with the new internal heating system. The improvements achieved allow reducing the power requirements on pultrusion process, and thus minimize industrial costs and contribute to a more sustainable pultrusion manufacturing industry.
Resumo:
The effect of pre-meal tomato intake in the anthropometric indices and blood levels of triglycerides, cholesterol, glucose, and uric acid of a young women population (n=35, 19.6 ± 1.3 years) was evaluated. During 4 weeks, daily, participants ingested a raw ripe tomato (~90 g) before lunch. Their anthropometric and biochemical parameters were measured repeatedly during the follow-up time. At the end of the 4 weeks, significant reductions were observed on body weight (-1.09 ± 0.12 kg on average), % fat (-1.54 ± 0.52%), fasting blood glucose (-5.29 ± 0.80 mg/dl), triglycerides (-8.31 ± 1.34 mg/dl), cholesterol (-10.17 ± 1.21 mg/ dl), and uric acid (-0.16 ± 0.04 mg/dl) of the participants. The tomato pre-meal ingestion seemed to interfere positively in body weight, fat percentage, and blood levels of glucose, triglycerides, cholesterol, and uric acid of the young adult women that participated in this study.
Resumo:
Many-core platforms are an emerging technology in the real-time embedded domain. These devices offer various options for power savings, cost reductions and contribute to the overall system flexibility, however, issues such as unpredictability, scalability and analysis pessimism are serious challenges to their integration into the aforementioned area. The focus of this work is on many-core platforms using a limited migrative model (LMM). LMM is an approach based on the fundamental concepts of the multi-kernel paradigm, which is a promising step towards scalable and predictable many-cores. In this work, we formulate the problem of real-time application mapping on a many-core platform using LMM, and propose a three-stage method to solve it. An extended version of the existing analysis is used to assure that derived mappings (i) guarantee the fulfilment of timing constraints posed on worst-case communication delays of individual applications, and (ii) provide an environment to perform load balancing for e.g. energy/thermal management, fault tolerance and/or performance reasons.
Resumo:
Com a crescente sensibilização mundial relativa ao aquecimento global, provocado pela alta quantidade de emissão de gases com efeito de estufa, torna-se imperativa a redução de consumos de combustíveis fósseis e consecutivas emissões. Ao nível da construção civil, uma intervenção eficaz na prevenção de perdas de ar aquecido poderá levar a diminuições superiores a 50% na utilização de energia. Este trabalho pretende estudar a importância da eficiência energética nos edifícios, com especial enfoque na sua permeabilidade ao ar. O ensaio de porta ventiladora permite avaliar esta permeabilidade e identificar os locais onde se dão as infiltrações, nomeadamente com auxílio da câmara térmica. O principal objectivo é estudar a aplicação deste ensaio na legislação em desenvolvimento no âmbito da certificação energética, através da comparação dos resultados de quatro habitações distintas. Também ao nível da eficiência energética, será obtida a classe energética, segundo a legislação em vigor à corrente data em Portugal, de uma das habitaçãoes ensaiadas e propostas medidas de melhoria para o desempenho energético desta. Do estudo efectuado é destacado o facto de o valor de renovações horárias do ar interior de uma fracção ser sempre inferior quando obtido unicamente através da legislação em desenvolvimento, em comparação com a obtenção deste através da legislação com auxílio do ensaio da porta ventiladora, o que leva a um grande desincentivo na utilização deste.