3139175 documents found, page 312620 of 313918

Porous functionally graded plates: na assessment of the influence of shear corre...

The known multifunctional characteristic of porous graded materials makes them very attractive in a number of diversified application fields, which simultaneously poses the need to deepen research efforts in this broad field. The study of functionally graded porous materials is a research topic of interest, particularly concerning the modeling of porosity distributions and th ecorresponding estimations of their mat...

Modelização de um sistema de simulação de uma aeronave aplicado a uma plataform...

Esta tese apresenta o desenvolvimento de um simulador de voo, através da aplicação de um modelo dinâmico de uma aeronave e de sistemas de realidade virtual a uma plataforma electromecânica de Gough-Stewart. Para o efeito, utiliza-se o modelo da aeronave Cessna-172. Neste sentido, apresenta-se o estudo e a análise do sistema de realidade virtual utilizado, confirma-se o funcionamento do modelo matemático da aero...

Optimização de instalações frigoríficas para um matadouro industrial em ambient...

O propósito deste trabalho é a pesquisa com vista à elaboração de um projecto em âmbito de estágio em condições reais de um matadouro de bovinos, suínos e ovinos/caprinos. O presente trabalho integra uma unidade industrial localizada em Ur, perto dos Pirinéus (França) com uma capacidade de abate de 80 bovinos e 500 suínos e 600 ovinos, nas cerca de 5 horas de trabalho diárias. Toda a carne consumível advém dest...

The impact of retargeting on consumer well-being and purchase intention

In this study, the authors approached retargeting. It consists of an analysis of products seen by the user, but not purchased, and with a mathematical algorithm, present advertising in real-time, based on their behavior on different online platforms, as well as measuring the impact produced by this advertising technique on consumers' well-being. They also tried to assess its influence on consumers' purchase int...

Microbial occupational exposure in e-waste recycling: biological hazards, their...

E-waste management is a major environmental concern that also poses serious risks to occupational health. While e-waste workers are exposed to a variety of chemicals, little is known about occupational exposure to microbiological agents. This study aims to fill that gap. For that purpose, two e-waste facilities were assessed: one battery-recycling facility (BRF), and another facility (SRE) dedicated to e-waste ...

HBM4EU chromates study: usefulness of measurement of blood chromium levels in t...

Occupational exposures to hexavalent chromium (Cr(VI)) can occur in welding, hot working stainless steel processing, chrome plating, spray painting, and coating activities. Recently, within the human biomonitoring for Europe initiative (HBM4EU), a study was performed to assess the suitability of different biomarkers to assess the exposure to Cr(VI) in various job tasks. Blood-based biomarkers may prove useful w...

Blockchain, IoT and Smart Grids Challenges for Energy Systems

Confiança: o nó górdio da informação financeira

Desde o início do século XXI tem-se assistido à revelação de uma série de escândalos de cariz económico e financeiro, cada um mais surpreendente que o anterior. Quase sempre aqueles escândalos são categorizados como fraudes contabilísticas quando, na verdade, se referem à manipulação dos resultados e à falta de princípios éticos. Organizações até aí insuspeitas pela reputação adquirida surpreenderam a Sociedade...

Accuracy of COVID-19 diagnostic tests via infrared spectroscopy: a systematic r...

This study aims to synthesize the evidence on the accuracy parameters of COVID-19 diagnosis methods using infrared spectroscopy (FTIR). A systematic review with searches in PubMed and Embase was performed (September 2023). Studies reporting data on test specificity, sensitivity, true positive, true negative, false positive, and false negative using different human samples were included. Meta-analysis of accurac...

Estimation of signal subspace on hyperspectral data

Dimensionality reduction plays a crucial role in many hyperspectral data processing and analysis algorithms. This paper proposes a new mean squared error based approach to determine the signal subspace in hyperspectral imagery. The method first estimates the signal and noise correlations matrices, then it selects the subset of eigenvalues that best represents the signal subspace in the least square sense. The e...