152 research outputs found

    Projeto e desenvolvimento da arquitetura de um robô agrícola móvel

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    Parameters such as tolerance, scale and agility utilized in data sampling for using in Precision Agriculture required an expressive number of researches and development of techniques and instruments for automation. It is highlighted the employment of methodologies in remote sensing used in coupled to a Geographic Information System (GIS), adapted or developed for agricultural use. Aiming this, the application of Agricultural Mobile Robots is a strong tendency, mainly in the European Union, the USA and Japan. In Brazil, researches are necessary for the development of robotics platforms, serving as a basis for semi-autonomous and autonomous navigation systems. The aim of this work is to describe the project of an experimental platform for data acquisition in field for the study of the spatial variability and development of agricultural robotics technologies to operate in agricultural environments. The proposal is based on a systematization of scientific work to choose the design parameters utilized for the construction of the model. The kinematic study of the mechanical structure was made by the virtual prototyping process, based on modeling and simulating of the tension applied in frame, using the.Parâmetros, como tolerância, escala e agilidade empregados na amostragem de dados para uso em Agricultura de Precisão, exigem um expressivo número de pesquisas no desenvolvimento de instrumentos e técnicas para automação. Destacam-se a utilização de metodologias em sensoriamento remoto utilizadas em conjunto com o Sistema de Informação Geográfica (SIG), adaptados ou desenvolvidos para o uso agrícola. Visando a isso, a aplicação de Robôs Agrícolas Móveis é uma forte tendência, principalmente na União Europeia, EUA e Japão. No Brasil, pesquisas são necessárias para o desenvolvimento de plataformas robóticas, que sirvam de base para sistemas de navegação autônomos ou semiautônomos. O objetivo deste trabalho é descrever o projeto de uma plataforma experimental para a aquisição de dados em campo para o estudo da variabilidade espacial e desenvolvimento de tecnologias para operação de robôs em ambiente agrícola. A proposta baseia-se em uma sistematização de trabalhos científicos que norteiam a escolha dos parâmetros de projeto utilizados para a construção do modelo. O estudo cinemático da estrutura mecânica foi feito pelo processo de prototipagem virtual, baseado na modelagem e simulação das tensões aplicadas no chassi, utilizando o método dos elementos finitos, em função dos conceitos básicos de cinemática de robôs móveis e experiências em trabalhos anteriores.(FAPESP) São Paulo Research Foundation(CNPq) National Council of Scientific and Technological Developmen

    Retrospective case-series analysis of haematological malignancies in goldmining areas of South Africa

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    Background. South Africa (SA)’s high levels of environmental contamination of mine tailings from uranium and its decay products, coupled with remarkably short distances between mine tailings and residential areas, raise concern about whether there is an association between environmental uranium exposure and risk of cancer, including haematological malignancies.Objectives. We reviewed information on cases from the central hospital offering cancer diagnostics and treatment in a major mining area of SA to describe their basic clinical and demographic characteristics, as part of assessing whether a cancer epidemiological study in this area would be feasible.Methods. Basic clinical, demographic and residential information on patients with haematological malignancy diagnosed between 2004 and 2013 was collected retrospectively from the patient files at Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg.Results. In total, 1 880 patients aged 18 - 94 years were identified. Referral from distant provinces was not uncommon, but >80% lived within 50 km of the hospital. Non-Hodgkin’s lymphoma accounted for 44% of the haematological malignancies, followed by leukaemia with 26%. HIV status was known for 93% of the patients, of whom 47% were HIV-positive.Conclusions. Caution is required when interpreting spatial distributions of patients, given inaccuracies in residential addresses and referral patterns to the hospital, and with HIV and other infections probable important confounders. Our study therefore shows that active case recruitment is required for accurate assessment of residential information. However, some findings on spatial distributions in the study warrant the continuation of efforts to develop a study protocol to investigate the possible link between uranium exposure in mining areas and haematological malignancies in residents. Disproportionately high incidence rates of haematological malignancies observed in specific districts would be relevant for further investigation.

    Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use

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    Since machine tools are used extensively throughout their functional life and consequently consuming valuable natural resources and emitting harmful pollutants during this time, this study reviews strategies for characterizing and reducing the energy consumption of milling machine tools during their use. The power demanded by a micromachining center while cutting low carbon steel under varied material removal rates was measured to model the specific energy of the machine tool. Thereafter the power demanded was studied for cutting aluminum and polycarbonate work pieces for the purpose of comparing the difference in cutting power demand relative to that of steel

    Retrospective caseseries analysis of haematological malignancies in goldmining areas of South Africa

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    Background. South Africa (SA)’s high levels of environmental contamination of mine tailings from uranium and its decay products, coupled with remarkably short distances between mine tailings and residential areas, raise concern about whether there is an association between environmental uranium exposure and risk of cancer, including haematological malignancies.Objectives. We reviewed information on cases from the central hospital offering cancer diagnostics and treatment in a major mining area of SA to describe their basic clinical and demographic characteristics, as part of assessing whether a cancer epidemiological study in this area would be feasible.Methods. Basic clinical, demographic and residential information on patients with haematological malignancy diagnosed between 2004 and 2013 was collected retrospectively from the patient files at Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg.Results. In total, 1 880 patients aged 18 - 94 years were identified. Referral from distant provinces was not uncommon, but >80% lived within 50 km of the hospital. Non-Hodgkin’s lymphoma accounted for 44% of the haematological malignancies, followed by leukaemia with 26%. HIV status was known for 93% of the patients, of whom 47% were HIV-positive.Conclusions. Caution is required when interpreting spatial distributions of patients, given inaccuracies in residential addresses and referral patterns to the hospital, and with HIV and other infections probable important confounders. Our study therefore shows that active case recruitment is required for accurate assessment of residential information. However, some findings on spatial distributions in the study warrant the continuation of efforts to develop a study protocol to investigate the possible link between uranium exposure in mining areas and haematological malignancies in residents. Disproportionately high incidence rates of haematological malignancies observed in specific districts would be relevant for further investigation.Â

    Seatbelt use and risk of major injuries sustained by vehicle occupants during motor-vehicle crashes: A systematic review and meta-analysis of cohort studies

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    BackgroundIn 2004, a World Health Report on road safety called for enforcement of measures such as seatbelt use, effective at minimizing morbidity and mortality caused by road traffic accidents. However, injuries caused by seatbelt use have also been described. Over a decade after publication of the World Health Report on road safety, this study sought to investigate the relationship between seatbelt use and major injuries in belted compared to unbelted passengers.MethodsCohort studies published in English language from 2005 to 2018 were retrieved from seven databases. Critical appraisal of studies was carried out using the Scottish Intercollegiate Guidelines Network (SIGN) checklist. Pooled risk of major injuries was assessed using the random effects meta-analytic model. Heterogeneity was quantified using I-squared and Tau-squared statistics. Funnel plots and Egger's test were used to investigate publication bias. This review is registered in PROSPERO (CRD42015020309).ResultsEleven studies, all carried out in developed countries were included. Overall, the risk of any major injury was significantly lower in belted passengers compared to unbelted passengers (RR 0.47; 95%CI, 0.29 to 0.80; I-2=99.7; P=0.000). When analysed by crash types, belt use significantly reduced the risk of any injury (RR 0.35; 95%CI, 0.24 to 0.52). Seatbelt use reduces the risk of facial injuries (RR=0.56, 95% CI=0.37 to 0.84), abdominal injuries (RR=0.87; 95% CI=0.78 to 0.98) and, spinal injuries (RR=0.56, 95% CI=0.37 to 0.84). However, we found no statistically significant difference in risk of head injuries (RR=0.49; 95% CI=0.22 to 1.08), neck injuries (RR=0.69: 95%CI 0.07 to 6.44), thoracic injuries (RR 0.96, 95%CI, 0.74 to 1.24), upper limb injuries (RR=1.05, 95%CI 0.83 to 1.34) and lower limb injuries (RR=0.77, 95%CI 0.58 to 1.04) between belted and non-belted passengers.ConclusionIn sum, the risk of most major road traffic injuries is lower in seatbelt users. Findings were inconclusive regarding seatbelt use and susceptibility to thoracic, head and neck injuries during road traffic accidents. Awareness should be raised about the dangers of inadequate seatbelt use. Future research should aim to assess the effects of seatbelt use on major injuries by crash type

    Spatial variability of vegetation index and soil properties in an integrated crop-livestock system

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    The knowledge of soil property spatial variability is useful for determining the rational use of inputs, such as the site-specific application of lime and fertilizer. The objective of this study was to evaluate the vegetation index and spatial variability of physical and chemical soil properties in an integrated crop-livestock system (ICLS). Soil samples were taken from a 6.9 ha area in a regular hexagon grid at 0-0.20 m depths. Soil P, K, Ca, Mg, and cation exchange capacity - CEC; base saturation; clay and sand were analyzed. Soil electrical conductivity (ECa) was measured with a contact sensor. The site was evaluated at the end of the corn season (April) and during forage production (October) using Landsat 5 images, remote sensing techniques and a geographic information system (GIS). Results showed that the normalized difference vegetation index (NDVI) was associated with ECa and soil parameters, indicating crop and pasture variations in the ICLS. Geostatistics and GIS were effective tools for collecting data regarding the spatial variability of soil and crop indicators, identifying variation trends in the data, and assisting data interpretation to determine adequate management strategies.201

    Precision agriculture in Brazil: The trajectory of 25 years of scientific research.

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    Precision agriculture (PA) stands out as an innovative way to manage production resources, increasing the efficiency and the socioeconomic and environmental sustainability of agricultural systems. In Brazil, the principles and tools of PA started to be adopted in the late 1990s. To reveal the scientific trajectory and advances in PA taken over the past 25 years in Brazil, we conducted a comprehensive and systematic literature review. After searching for available peer-reviewed literature, 442 publications were selected to compose the database. Our bibliometric review showed that the scientific PA network is growing in Brazil, with the number and quality of publications, the number of interactions among research groups, and the number of international collaborations increasing. Soil and plant management are the two main pillars of PA research (~61% of the publications).More recently, research has evolved to include other areas, such as the use of proximal sensors to monitor soil and crop development, remote sensing using images from satellites and remotely piloted aircraft systems, and the development of decision support tools. A substantial part of Brazilian PA research is marked by the evaluation and adaptation of imported technologies, a scenario that is slowly changing with the growth of well-trained human resources and advances in national industry.Based on Brazilian scientific history and remaining challenges, the key potential areas for future research are (i) the development of digitally based decision support systems, i.e., a shift of focus from on-farm data technologies towards effective, site-specific decision making based on digital data and improved analytics; (ii) on-farm precision experimentation to underpin on-farm data collection and the development of new decision tools; and (iii) novel machine learning approaches to promote the implementation of digitally based decision support systems
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