152 research outputs found

    Numerical fluid dynamics simulation for drones’ chemical detection

    Get PDF
    The risk associated with chemical, biological, radiological, nuclear, and explosive (CBRNe) threats in the last two decades has grown as a result of easier access to hazardous materials and agents, potentially increasing the chance for dangerous events. Consequently, early detection of a threat following a CBRNe event is a mandatory requirement for the safety and security of human operators involved in the management of the emergency. Drones are nowadays one of the most advanced and versatile tools available, and they have proven to be successfully used in many different application fields. The use of drones equipped with inexpensive and selective detectors could be both a solution to improve the early detection of threats and, at the same time, a solution for human operators to prevent dangerous situations. To maximize the drone’s capability of detecting dangerous volatile substances, fluid dynamics numerical simulations may be used to understand the optimal configuration of the detectors positioned on the drone. This study serves as a first step to investigate how the fluid dynamics of the drone propeller flow and the different sensors position on-board could affect the conditioning and acquisition of data. The first consequence of this approach may lead to optimizing the position of the detectors on the drone based not only on the specific technology of the sensor, but also on the type of chemical agent dispersed in the environment, eventually allowing to define a technological solution to enhance the detection process and ensure the safety and security of first responders

    Enhancing Radiation Detection by Drones through Numerical Fluid Dynamics Simulations

    Get PDF
    This study addresses the optimization of the location of a radioactive-particle sensor on a drone. Based on the analysis of the physical process and of the boundary conditions introduced in the model, computational fluid dynamics simulations were performed to analyze how the turbulence caused by drone propellers may influence the response of the sensors. Our initial focus was the detection of a small amount of radioactivity, such as that associated with a release of medical waste. Drones equipped with selective low-cost sensors could be quickly sent to dangerous areas that first responders might not have access to and be able to assess the level of danger in a few seconds, providing details about the source terms to Radiological-Nuclear (RN) advisors and decision-makers. Our ultimate application is the simulation of complex scenarios where fluid-dynamic instabilities are combined with elevated levels of radioactivity, as was the case during the Chernobyl and Fukushima nuclear power plant accidents. In similar circumstances, accurate mapping of the radioactive plume would provide invaluable input-data for the mathematical models that can predict the dispersion of radioactivity in time and space. This information could be used as input for predictive models and decision support systems (DSS) to get a full situational awareness. In particular, these models may be used either to guide the safe intervention of first responders or the later need to evacuate affected regions

    Enhancing radiation detection by drones through numerical fluid dynamics simulations

    Get PDF
    This study addresses the optimization of the location of a radioactive-particle sensor on a drone. Based on the analysis of the physical process and of the boundary conditions introduced in the model, computational fluid dynamics simulations were performed to analyze how the turbulence caused by drone propellers may influence the response of the sensors. Our initial focus was the detection of a small amount of radioactivity, such as that associated with a release of medical waste. Drones equipped with selective low-cost sensors could be quickly sent to dangerous areas that first responders might not have access to and be able to assess the level of danger in a few seconds, providing details about the source terms to Radiological-Nuclear (RN) advisors and decision-makers. Our ultimate application is the simulation of complex scenarios where fluid-dynamic instabilities are combined with elevated levels of radioactivity, as was the case during the Chernobyl and Fukushima nuclear power plant accidents. In similar circumstances, accurate mapping of the radioactive plume would provide invaluable input-data for the mathematical models that can predict the dispersion of radioactivity in time and space. This information could be used as input for predictive models and decision support systems (DSS) to get a full situational awareness. In particular, these models may be used either to guide the safe intervention of first responders or the later need to evacuate affected regions

    First-line treatment and outcome of elderly patients with primary central nervous system lymphoma (PCNSL)—a systematic review and individual patient data meta-analysis

    Get PDF
    Evidence for prognosis and treatment of elderly patient with primary central nervous system is limited. High-dose methotrexate should be applied whenever possible, especially combination with oral alkylating agents is a promising approach. Further combinations with other intravenous drugs do not seem to improve outcome. More prospective trials designed for elderly PCNSL patients are warrante

    Família, dificuldades no aprendizado e problemas de comportamento em escolares

    Get PDF
    Resumo Nos anos escolares, família e escola são contextos em que se engendram mecanismos de risco e proteção para trajetórias favoráveis ou não de desenvolvimento das crianças. Dificuldades adaptativas precoces, expressas em altos níveis de problemas emocionais e/ou comportamentais, têm sido associadas a trajetórias desfavoráveis. O presente estudo objetivou testar um modelo de predição de problemas de comportamento em escolares, tendo como preditores variáveis de apoio ao desenvolvimento e adversidade no contexto familiar, bem como a presença da queixa escolar, sinalizando adversidade no contexto escolar. Participaram 60 crianças, de 7 a 11 anos, e suas mães, recrutadas em escola pública de Ensino Fundamental e em clínica-escola de psicologia. Os instrumentos utilizados foram Matrizes Progressivas Coloridas de Raven, Inventário de Comportamento da Infância e Adolescência (CBCL), Inventário de Recursos do Ambiente Familiar (RAF), subescala Vida Familiar, da Escala de Eventos Adversos (EEA). A coleta ocorreu na clínica e na escola. Os dados foram analisados por meio de regressão linear múltipla, verificando-se o poder explicativo das variáveis ambientais sobre os desfechos comportamentais. Os resultados apontaram a adversidade escolar como principal preditor de problemas de atenção, problemas sociais e comportamento agressivo. A adversidade familiar foi associada a problemas internalizantes e externalizantes. Duas modalidades de apoio familiar (rotina regular no dia a dia e atividades de lazer no tempo livre) parecem implicadas na atenuação dos problemas de comportamento. Destaca-se que esses são recursos passíveis de intervenção

    Caracterização da queixa escolar no Centro de Psicologia Aplicada da Universidade Federal de Juiz de Fora

    Get PDF
    A queixa escolar vem se constituindo, historicamente, como um dos motivos mais frequentes de encaminhamentos de crianças para os serviços-escola de Psicologia, traduzindo, pela sua complexidade, um desafio para a formação e práticas no âmbito da psicologia escolar/educacional. Diante da necessidade de aperfeiçoar o atendimento à clientela e o processo de triagem, o presente estudo objetivou analisar os prontuários referentes à queixa escolar de pacientes atendidos no Centro de Psicologia Aplicada da Universidade Federal de Juiz de Fora, Minas Gerais, Brasil, num total de 1.590 documentos, no período de 1996 a 2009. Os resultados quanto à clientela evidenciaram a prevalência de meninos na faixa entre 9 e 13 anos de idade, com predomínio de encaminhamentos oriundos de escolas de periférias da cidade. Quanto à queixa, constatou-se expressiva coocorrência de problemas comportamentais e de aprendizagem. Os dados permitem uma reflexão crítica acerca da queixa escolar e de alguns fatores contextuais, bem como a necessidade de aperfeiçoamento da ficha de triagem
    • …
    corecore