Thermal performance of a PCM firefighting suit considering transient periods of fire exposure, post - fire exposure and resting phases

Firefighting scenarios may be characterized by various transient periods (i.e. phases), which consist of diverse environmental conditions. Firefighters usually encounter fire exposure, post fire exposure and resting phases. Development of new and improved protective clothing must be able to provide protection throughout all these phases, as burnouts may still occur after fire exposure due to accumulation of heat in the garment. The incorporation of phase change materials (PCMs) in firefighting garments has been shown to minimize the potential of heat hazards only during fire exposure. Thus to get more knowledge on their thermal performance, in the present study, the effect of PCM incorporation in post fire and resting phases were also numerically studied. The numerical code was validated for all phases. Five potential PCM candidates were considered. Exposure phases were characterized by high- medium and low- heat flux intensities (84, 12 and 5 kW.m(-2)) with variable exposure times whilst post -exposure and resting phases where characterized by different wind speeds (i.e. ambient convective coefficients). Optimal PCM masses, times to second and third - degree burns as well as PCM suit cooling times were calculated to reflect thermal protective performance in each respective phase. The data generated allows for PCM short-listing from a set of potential PCM candidates along with its geometrical parameters, considering a wide range of characteristics of the various phases that consist a typical firefighting scenario

The impact of water on firefighter protective clothing thermal performance and steam burn occurrence in firefighters

Exposure to oscillating heat fluxes while having variable water contents in the thermal protective clothing (T.P. C) is possible in a real firefighting scenario. The occurrence of steam burns becomes inevitable in certain conditions which are still unidentified in the literature. In light of such, in this study, the effect of water distribution on thermal protective clothing (T.P.C) performance is studied for various environmental conditions (i.e., fixed and transient values of heat flux). A numerical approach is used to simulate heat and mass transport in the T.P.C.. Parametric studies are performed, where the exposure heat flux (0-80 kW/m(2)) and initial quantities of water in the T.P.C. are varied and correlated with second-degree burn times. The presence of water in the outer shell increases second-degree burn times, while water in the inner layer has the opposite effect for high heat fluxes. For the tested heat fluxes, burns obtained are majorly of a scald nature. The results generated allow for identifying environmental and protective clothing conditions where steam burns may become a potential hazard. This study can directly impact the proceedings for firefighters to take in certain environmental conditions and aid in the design of more effective firefighting protective suits

Optimization of the focal plane for the gamma-ray imager mission

Em Abril de 2004, a Agência Espacial Europeia (ESA) lançou uma chamada para decidir os temas científicos que teriam maior impacto no futuro. Em 2005, esse conjunto de temas foi estabelecido e deu-se início ao programa Cosmic Vision 2015- 2025. Várias missões foram propostas no âmbito deste programa. Um consórcio de várias instituições provenientes de diferentes países formou-se e a missão Gamma-Ray Imager (GRI) foi proposta. O objectivo desta missão é reunir informações sobre fontes específicas de radiação gama. O seu desenvolvimento tem implicado um esforço significativo desde a sua proposta. Este trabalho enquadra-se nesse esforço. A sensibilidade do instrumento principal desta missão é o assunto principal deste trabalho. Desde a missão CGRO (Compton Gamma Ray Observatory), lançada no início da década de 90 do século passado, à missão INTEGRAL (International Gamma- Ray Astrophysics Laboratory), lançada em 2002, o aumento da sensibilidade foi conseguido através do aumento da área de colecção dos fotões. Contudo, já não é possível melhorar a sensibilidade através do aumento da área de colecção. A missão GRI pretende ultrapassar este problema através do uso de lentes de Laue que foquem a radiação incidente num plano focal. No entanto, alguns trabalhos indiciam uma melhoria da sensibilidade através da estratificação do volume activo em várias camadas. Isto significa que poderão existir duas soluções que podem ser usadas para melhorar a sensibilidade e é importante quantificar o impacto de cada uma delas no valor da mesma. A realização deste trabalho passou por um conjunto de tarefas. A primeira foi estudar o comportamento da razão sinal/ruído ao expor diferentes geometrias a diferentes fontes com diferentes distribuições de energia. Seguidamente, estudou-se a variação da sensibilidade com o aumento do número de placas de volume sensível, mantendo constante o volume de detecção, com o fim de comparar os resultados obtidos com o aumento de sensibilidade que se pode esperar através do uso de uma lente de Laue. A última grande tarefa foi o cálculo da polarização mínima detectável (MDP - Minimum Detectable Polarization) para uma geometria simplificada do plano focal a utilizar na missão GRI. Todos os resultados que constam deste trabalho foram obtidos através da livraria de software Geant4, lançada pelo CERN, e do software MEGAlib, criado pelo Dr. Andreas Zoglauer

Ffau—framework for fully autonomous uavs

Nr. 024539 (POCI-01-0247-FEDER-024539) under grant agreement No 783221 UID/EEA/00066/2019Unmanned Aerial Vehicles (UAVs), although hardly a new technology, have recently gained a prominent role in many industries being widely used not only among enthusiastic consumers, but also in high demanding professional situations, and will have a massive societal impact over the coming years. However, the operation of UAVs is fraught with serious safety risks, such as collisions with dynamic obstacles (birds, other UAVs, or randomly thrown objects). These collision scenarios are complex to analyze in real-time, sometimes being computationally impossible to solve with existing State of the Art (SoA) algorithms, making the use of UAVs an operational hazard and therefore significantly reducing their commercial applicability in urban environments. In this work, a conceptual framework for both stand-alone and swarm (networked) UAVs is introduced, with a focus on the architectural requirements of the collision avoidance subsystem to achieve acceptable levels of safety and reliability. The SoA principles for collision avoidance against stationary objects are reviewed and a novel approach is described, using deep learning techniques to solve the computational intensive problem of real-time collision avoidance with dynamic objects. The proposed framework includes a web-interface allowing the full control of UAVs as remote clients with a supervisor cloud-based platform. The feasibility of the proposed approach was demonstrated through experimental tests using a UAV, developed from scratch using the proposed framework. Test flight results are presented for an autonomous UAV monitored from multiple countries across the world.publishersversionpublishe

Ectopic beats arise from micro-reentries near infarct regions in simulations of a patient-specific heart model

Ectopic beats are known to be involved in the initiation of a variety of cardiac arrhythmias. Although their location may vary, ectopic excitations have been found to originate from infarct areas, regions of micro-fibrosis and other heterogeneous tissues. However, the underlying mechanisms that link ectopic foci to heterogeneous tissues have yet to be fully understood. In this work, we investigate the mechanism of micro-reentry that leads to the generation of ectopic beats near infarct areas using a patient-specific heart model. The patient-specific geometrical model of the heart, including scar and peri-infarct zones, is obtained through magnetic resonance imaging (MRI). The infarct region is composed of ischemic myocytes and non-conducting cells (fibrosis, for instance). Electrophysiology is captured using an established cardiac myocyte model of the human ventricle modified to describe ischemia. The simulation results clearly reveal that ectopic beats emerge from micro-reentries that are sustained by the heterogeneous structure of the infarct regions. Because microscopic information about the heterogeneous structure of the infarct regions is not available, Monte-Carlo simulations are used to identify the probabilities of an infarct region to behave as an ectopic focus for different levels of ischemia and different percentages of non-conducting cells. From the proposed model, it is observed that ectopic beats are generated when a percentage of non-conducting cells is near a topological metric known as the percolation threshold. Although the mechanism for micro-reentries was proposed half a century ago to be a source of ectopic beats or premature ventricular contractions during myocardial infarction, the present study is the first to reproduce this mechanism in-silico using patient-specific data.Peer ReviewedPostprint (published version

Effectiveness of Caregiver-Provided Individual Cognitive Interventions in Older Adults with Dementia

Background: In a society increasingly committed to promoting an active life in the community, new resources are needed to respond to the needs of citizens with Alzheimer’s disease and other forms of dementia. The potential of several individual cognitive interventions to be provided by caregivers has been explored in the literature. Objective: To synthesize the best available evidence on the effectiveness of caregiver-provided individual cognitive interventions in older adults with dementia. Methods: Systematic review of experimental studies on individual cognitive interventions for older adults with dementia. An initial search of MEDLINE and CINAHL was undertaken. Another search for published and unpublished studies was performed on major healthcare-related online databases in March 2018 and updated in August 2022. This review considered studies that included older adults with dementia, aged 60 years and over. All studies that met the inclusion criteria were assessed for methodological quality using a JBI standardized critical appraisal checklist. Data were extracted using a JBI data extraction form for experimental studies. Results: Eleven studies were included: eight randomized controlled trials and three quasi-experimental studies. Caregiver-provided individual cognitive interventions had several beneficial effects in cognitive domains, including memory, verbal fluency, attention, problem-solving, and autonomy in activities of daily living. Conclusion: These interventions were associated with moderate improvements in cognitive performance and benefits in activities of daily living. The findings highlight the potential of caregiver-provided individual cognitive interventions for older adults with dementia.info:eu-repo/semantics/publishedVersio

Cultural Landscape and Geoconservation: Conceptual Contributions Applied in Serra da Canastra, Brazil

This study deals with the cultural landscape, introduced in the Brazilian environmental legislation in 2009, as which frames and allows the development of geoconservation projects, including the creation of geoparks. It also intends to discuss the relations of cultural landscape and geodiversity conservation in Serra da Canastra region, SW Minas Gerais. The region is notable for a rich combination of natural and cultural heritage. This study presents strategies for the legal modeling of a protected cultural landscape and a geopark in the region, considering the need to protect geological and cultural site

Modelos simplificados para acoplamento eletromecânico de miócito cardíaco

Modelos computacionais que descrevem a eletromecânica do coração são ferramentas importantes para a interpretação e a avaliação de medidas fisiológicas e para considerações de vários fenômenos. Neste trabalho, propomos modelos simplificados que reproduzam qualitativamente o fenômeno de contração de cardiomiócitos. A fim de reduzir a complexidade e o custo computacional foram desenvolvidos dois modelos simplificados baseado em algumas equações diferenciais ordinárias. Para o ajuste dos parâmetros do modelos um algoritmo genético foi utilizado. Os resultados obtidos foram satisfatórios quando comparados a modelos existentes na literatura.Publicado en: Mecánica Computacional vol. XXXV, no. 9.Facultad de Ingenierí

MODELAGEM DINÂMICA ESPACIAL DAS ALTERAÇÕES DE COBERTURA E USO DA TERRA RELACIONADAS À EXPANSÃO CANAVIEIRA

A avaliação das mudanças na paisagem é fundamental para a eficiência na gestão territorial. O objetivo deste trabalho é parametrizar e calibrar um modelo de mudança de cobertura e uso, além de validar as simulações associadas à expansão canavieira em Arealva-SP, no período compreendido entre 2005 e 2010. Os mapas inicial e final foram corregistrados e,  após a rasterização, foi realizada uma tabulação cruzada, gerando-se um mapa de mudanças e a respectiva matriz de transição. O modelo adotado foi o Dinamica EGO, e seu desempenho foi avaliado por meio de um método baseado no conceito de incerteza de localização (fuzziness of location), no qual a representação de uma célula é influenciada por ela mesma, e, em menor magnitude, pela sua vizinhança. Há predominância de pastagens e baixo índice de área de vegetação nativa. As mudanças mais relevantes estão relacionadas à expansão canavieira e à retração de pastagens. O valor da similaridade fuzzy entre o mapa simulado e o mapa-referência, para a janela de tamanho 11x11 e função de decaimento constante, foi de 0.52. Foi possível aprimorar o conhecimento dos fatores direcionadores das mudanças de cobertura e uso, propiciando a revelação das forçantes dessas mudanças