451 research outputs found

    Intelligent monitoring and management platform for the prevention of olive pests and diseases, including IoT with sensing, georeferencing and image acquisition capabilities through computer vision

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    Climate change affects global temperature and precipitation patterns. These effects, in turn, influence the intensity and, in some cases, the frequency of extreme environmental events, such as forest fires, hurricanes, heat waves, floods, droughts, and storms. In general, these events can be particularly conducive to the appearance of plant pests and diseases. The availability of models and a data collection system is crucial to manage pests and diseases in sustainable agricul-tural ecosystems. Agricultural ecosystems are known to be complex, multivariable, and unpredict-able. It is important to anticipate crop pests and diseases in order to improve its control in a more ecological and economical way (e.g., precision in the use of pesticides). The development of an intel-ligent monitoring and management platform for the prevention of pests and diseases in olive groves at Trás-os- Montes region will be very beneficial. This platform must: a) integrate data from multi-ple data sources such as sensory data (e.g., temperature), biological observations (e.g., insect counts), georeferenced data (e.g., altitude) or digital images (e.g., plant images); b) systematize these data into a regional repository; c) provide relevant forecasts for pest and diseases. Convolutional Neural Networks (CNNs) can be a valuable tool for the identification and classi-fication of images acquired by Internet of Things (IoT).info:eu-repo/semantics/publishedVersio

    Strain field analysis of cancellous bone under compression by image correlation

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    Experimental mechanical analysis of cancellous bone has been performed to capture the global strain field of specimens under compression. One major objective is to assess the test procedure and obtain the cancellous bone mechanical properties. Now a day, several techniques are available for the experimental measurement of the field displacement. Among them, the Cross-Correlation is one of most simple’s techniques and can be applied to several studies cases. Based on the correlation of random speckle pattern between two images, the spatial displacement fields can be accessed. A simple digital camera or video recorder can be used without special light to capture the surface intensity pattern in each instant. If several images are taken during a test loading, the displacement field can be fallowed and subsequently the strain can be obtain by the spatial differentiation. Because of random surface pattern, the image can be divided in small areas, each of them pattern independent. By cross-correlating each of one between the two images, the relative displacement is obtained

    Reactions with light exotic nuclei

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    CNR*13 - Fourth International Workshop on Compound Nuclear Reactions and RelatedExperimental cross sections for the 6He+120Sn are analysed. Elastic scattering angular distributions and alpha particle production cross sections have been measured and are compared with the total reaction cross section

    Prevalência da exposição ao fumo ambiental do tabaco em casa e do tabagismo na população Portuguesa – o estudo INAsma

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    ResumoIntroduçãoNeste estudo, pretendemos: 1) estimar a prevalência, na população portuguesa, da exposição ao fumo ambiental do tabaco em casa; 2) estimar a prevalência de tabagismo em Portugal; 3) identificar as características sociais e pessoais associadas ao tabagismo ou à exposição ao fumo ambiental do tabaco.MétodosEstudo transversal consistindo na aplicação, à população, a nível nacional, de questionário telefónico. Completaram a entrevista 6 003 indivíduos. A exposição ao fumo ambiental do tabaco em casa foi definida como a exposição, em casa, ao fumo do tabaco de, pelo menos, um fumador atual. Por fumador entendeu-se um indivíduo com ≥ 15 anos que fumou, pelo menos, um cigarro por dia durante um período de um ano; um fumador atual fumou no último mês.ResultadosReferiram exposição ao fumo ambiental do tabaco em casa 26,6% dos participantes (IC 95%: 25,5-27,7). Viver num agregado familiar constituído por ≥ 4 pessoas (OR=2,31; IC 95%: [1,81-2,96]), ser fumador atual (OR=7,29; IC 95%: [5,74-9,26]) ou ter asma atual (OR=2,06; IC 95%: [1,45-2,94]) associaram-se positivamente à exposição ao fumo ambiental do tabaco. Na análise estratificada por sexo, o efeito da asma atual manteve-se apenas nas mulheres.Atualmente, 19,0% (IC 95%: 18,0-20,0) da população portuguesa é fumadora e 17,2% (IC 95%: 16,2-18,2) são ex-fumadores. A prevalência de fumadores atuais é mais elevada nos homens do que nas mulheres (26,5 versus 12,2%, p<0,001). A probabilidade de ser um fumador atual foi maior nos homens, nas pessoas mais instruídas e nos indivíduos expostos, em casa, ao fumo ambiental do tabaco. Na análise estratificada por sexo, o efeito da escolaridade manteve-se apenas nas mulheres.ConclusãoA exposição ao fumo ambiental do tabaco em casa foi mais elevada do que a anteriormente publicada. Crianças/adolescentes e doentes com asma podem ter um risco de exposição ambiental mais elevado. Este estudo apoia uma tendência decrescente da prevalência de tabagismo nos homens portugueses, mas uma tendência crescente nas mulheres.AbstractBackgroundWe aimed to: 1) estimate the prevalence of exposure to environmental tobacco smoke (ETS) at home in the Portuguese population; 2) estimate tobacco smoking prevalence in Portugal; 3) identify social and personal characteristics associated with smoking or exposure to ETS.MethodsNationwide, cross-sectional, population-based telephone survey. Overall, 6003 individuals completed the interview. ETS exposure at home was defined as exposure to at least one current smoker at home. A smoker was defined as someone with 15 years or older, smoking at least 1 cigarette per day during a year; a current smoker (CS) smoked in the last month.ResultsExposure to ETS at home was reported by 26.6% (95%CI 25.5-27.7) of the participants. Living in households with ≥4 persons (OR=2.31; 95%CI[1.81-2.96]), being a current smoker (OR=7.29; 95%CI[5.74-9.26]) or having current asthma (OR=2.06; 95%CI[1.45-2.94]) were factors positively associated with ETS exposure. When analyzed by gender, the effect of current asthma was only relevant to females.Currently 19.0% (95%CI 18.0-20.0) of the Portuguese population smokes tobacco and 17.2% (95%CI 16.2-18.2) are ex-smokers. CS prevalence is higher in males than females (26.5%versus 12.2%, p<0,001). The odds of being a CS were higher for males, the more educated, and those exposed to ETS at home. When analyzed by gender, school education only affected females.ConclusionExposure to ETS at home was higher than previously reported. Children/adolescents and asthma patients may have a higher risk of exposure. This report endorses a decreasing trend in the prevalence of tobacco smoking in Portuguese males, but a tendency to increase in females

    Optimizing The Inspection Routine For The Detection Of Electrical Energy Theft In Aes Eletropaulo In São Paulo, Brazil

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    This work describes the development of a non-invasive and low-cost process that allows for the improvement of the energy theft inspection routine, increasing the field inspection team productivity and reducing the customer's embarrassment in cases where no irregularity is found. This new process is based on the development of an electronic Ah meter device that can be installed on the customer's pole input connections to the power lines. Using the recorded Ah value in the device, it is possible to estimate, within a margin of error, the energy consumption of the customer during a small period, typically one week. This energy value is compared to the customer's regular energy meter reading for the same period. A comprehensive statistical study performed with a database of more than 80000 customers in distribution area of the utility company AES Eletropaulo in São Paulo, Brazil concludes that the comparison between these readings can clearly indicate when tampered or defective meters are found.728089Depuru, S., Wang, L., Devabhaktuni, V., Gudi, N., Measures and setbacks for controlling electricity theft (2010) IEEE North American Power Symposium-NAPS(2009) Bureau for Economic Growth, Agriculture and Trade, , U. S. Agency for International Development Washington, D. C., Transforming Electricity Consumers into Customers: Case Study of a Slum Electrification and Loss Reduction Project in São Paulo, BrazilOnat, N., Transmission and distribution losses of Turkey's power system (2010) Proceedings of the 4th WSEAS Conference on Advances in Energy Planning, Environmental Education and Renewable Energy SourcesSmith, T., Electricity theft comparative analysis (2003) Energy Policy, 32, pp. 2067-2076Fitch, M., Graham, C., (2000) Electricity and Gas Theft, , Centre for Utility Consumer Law, University of Leicester, UKKenny, C., Soreide, T., (2008) Grand Corruption in Utilities, , World Bank Policy Research Working Paper 4805Sarpa, C., (2008) Electricity Theft and Non-payment: Impact on the sa Generation Capacity Crisis, , Yelland, Conference PaperOnat, N., Techno-economic analysis of illegal electricity usage in Turkey and policy proposals (2010) WSEAS Transactions on Power Systems, 3, pp. 213-222Stajic, Z., Janjic, A., Simendic, Z., Power quality and electrical energy losses as a key drivers for smart grid platform development (2011) Proceedings of the 15th WSEAS International Conference on Systems - Recent Researches in System Science, pp. 417-422Kadurek, P., Blom, J., Cobben, J., Kling, W., Theft detection and smart metering practices and expectations in the Netherlands (2010) Innovative Smart Grid Technologies Conference Europe (ISGT Europe) IEEE PESOliveira-De Jesus, P., Alvarez, M., De Ponce Leao, M., Yusta, J., A novel approach to evaluate incremental transmission losses (2009) WSEAS Transactions on Power Systems, 1, pp. 12-21Ghajar, R.F., Khalife, J., Cost/benefit analysis of an AMR system to reduce electricity theft and maximize revenues for Électricité du Liban (2003) Applied Energy, 76 (1-3), pp. 25-37. , DOI 10.1016/S0306-2619(03)00044-8Nagi, J., Mohammad, A., Yap, K., Tiong, S., Ahmed, S., Non-technical loss analysis for detection of electricity theft using support vector machines (2008) Proceedings of the 2nd IEEE International Conference on Power and Energy (PECon 08), pp. 907-912(2008) MSP430FE42x Mixed Signal Microcontroller Data-sheet, , Texas Instruments(2011) CC2550 Low-cost Low-power 2.4 GHz RF Transmitter Data-Sheet, , Texas InstrumentsMorais, F., (2011) Development of an Electronic Wireless RMS Current Meter for Applications in Detection of Electrical Energy Theft, , M. Sc. Thesis in Electrical Engineering, Faculty of Computer and Electrical Engineering, University of Campinas, BrazilPomilio, J., Deckmann, S., Characterization and compensation of harmonics and reactive power of residential and commercial loads (2007) IEEE Transactions on Power Delivery,

    Caracterização e avaliação da actividade antifúngica de méis escuros e claros do Nordeste de Portugal.

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    O mel é consumido em larga escala no mundo inteiro e desempenha um papel importante na dieta humana, sendo também utilizado nas indústrias alimentar, farmacêutica e de cosméticos. A composição do mel é variável e depende da fonte floral usada na recolha do néctar, do clima, das condições ambientais e sazonais, bem como do manuseamento e do processamento. A qualidade do mel é determinada pelas suas propriedades sensoriais físicas e químicas. Estas propriedades são avaliadas através de parâmetros estabelecidos na legislação. Os objectivos deste trabalho foram a caracterização fisico-química, microbiológica e polínica de dois tipos de méis, claro e escuro, produzidos na região de Trás-os-Montes (nordeste de Portugal). Avaliou-se ainda a sua actividade antifúngica em Candida albicans, Candida krusei e Cryptococcus neoformans. Os parâmetros fisico-químicos avaliados foram os estabelecidos na norma do Codex Álimentarius e no Decreto-Lei 214/2003 de 18 de Setembro, e incluem pH, humidade, condutividade eléctrica, cinzas, acidez total, HMF (hidroximetilfuitral), índice diastásico, açúcares redutores e sacarose aparente. Todas as amostras analisadas respeitaram os limites legais estabelecidos, no entanto, observaram-se diferenças significativas entre os dois tipos de mel para todos os parâmetros determinados, excepto para o pH. De um modo geral, todas as amostras analisadas evidenciaram níveis de segurança aceitáveis para o consumidor, com números reduzidos de microrganismos mesofílicos, bolores e leveduras, não tendo sido detectados esporos de clostrídios sulfito-redutores. A análise polínica revelou que ambos os méis são monoflorais, sendo o pólen de Erica sp. o predominante nos méis escuros e o de Lavandulia sp. o mais abundante nos méis claros. O crescimento de todas as leveduras estudadas foi afectado na presença de mel, sendo C. neoformans a levedura mais susceptível. Os méis escuros demonstraram maior actividade antifúngica

    Espresso coffee residues in horticultural improvement

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    Spent coffee grounds are usually disposed as common garbage, without specific reuse strategies. Due to its recognized richness in bioactive compounds, the effect of espresso spent coffee grounds on lettuce´s macro- and micro- elements, as well as on its antioxidant and bioactive compounds, was assessed in order to ascertain its potential applicability in agroindustry, minimizing environmental issues and increasing vegetables nutritional features. Therefore, a greenhouse pot experiment with fresh and composted spent coffee (2.5 to 30% v/v) was conducted, using lettuce plants. The plants antioxidant capacity, assessed by radical scavenging effect and reducing power, was enhanced by spent coffee. Total reducing capacity was also improved, particularly for low spent coffee percentages. Additionally, very significant positive correlations were observed for all carotenoids in fresh spent coffee treatments. The results were not so significant with composted coffee residues, neither for vitamin E on both cases, but chlorophyll a was a good discriminating factor between control group and both treated samples. In opposition, a progressive decrease on all mineral elements ( magnesium, calcium, phosphorous, sodium, iron, manganese, zinc and copper) was verified with the increase of fresh spent coffee, except for potassium, while with low amounts of composted spent coffee ( 5%, v/v) a significant increase in the potassium content (by 40%), manganese (by 30%) and magnesium (by 20%) was observed. A sustainable bioconversion approach for coffee by-products was achieved, which might be extendable to other crops, and favourably contributes to the potentiation of vegetables nutritional quality.FCT (Fundação para a Ciência e Tecnologia) e FEDER através do programa COMPETE, através dos projetos FCOMP-01-0124-FEDER-008703 (FCT/PTDC/AGR-AAM/102447/2008) and PEst-C/EQB/LA0006/2011

    Normal-state conductivity in underdoped La_{2-x}Sr_xCuO_4 thin films: Search for nonlinear effects related to collective stripe motion

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    We report a detailed study of the electric-field dependence of the normal-state conductivity in La_{2-x}Sr_xCuO_4 thin films for two concentrations of doped holes, x=0.01 and 0.06, where formation of diagonal and vertical charged stripes was recently suggested. In order to elucidate whether high electric fields are capable of depinning the charged stripes and inducing their collective motion, we have measured current-voltage characteristics for various orientations of the electric field with respect to the crystallographic axes. However, even for the highest possible fields (~1000 V/cm for x=0.01 and \~300 V/cm for x=0.06) we observed no non-linear-conductivity features except for those related to the conventional Joule heating of the films. Our analysis indicates that Joule heating, rather than collective electron motion, may also be responsible for the non-linear conductivity observed in some other 2D transition-metal oxides as well. We discuss that a possible reason why moderate electric fields fail to induce a collective stripe motion in layered oxides is that fairly flexible and compressible charged stripes can adjust themselves to the crystal lattice and individual impurities, which makes their pinning much stronger than in the case of conventional rigid charge-density waves.Comment: 10 pages, 10 figures, accepted for publication in Phys. Rev.

    Impactos ambientais do manejo agroecológico da caatinga no Rio Grande do Norte.

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    O objetivo deste trabalho foi avaliar os impactos ambientais do manejo agroecológico da caatinga, em unidades de produção familiar no Rio Grande do Norte, pelo método Ambitec de produção animal - dimensão ambiental, desenvolvido pela Embrapa Meio Ambiente. Foram avaliadas sete unidades de produção familiar, em quatro projetos de assentamentos de reforma agrária do Município de Apodi, RN. Os dados para o levantamento foram obtidos por meio de questionários aplicados aos representantes das unidades produtivas familiares, que atribuíram, a cada variável estudada, um valor que representou a alteração proporcionada pela implementação da tecnologia. Após a inserção dos coeficientes de alteração de cada variável dos indicadores por unidade de produção, o coeficiente de impacto foi automaticamente calculado por meio da planilha Ambitec. O manejo agroecológico da caatinga resultou num impacto ambiental positivo, e suas maiores contribuições foram relacionadas aos efeitos positivos dos seguintes indicadores: capacidade produtiva do solo, uso de insumos materiais, qualidade do produto e diminuição da emissão de poluentes à atmosfera. Dois indicadores geraram efeitos negativos: o uso de energia e o uso de recursos naturais. Pela superioridade dos benefícios gerados, o manejo agroecológico da caatinga é uma inovação tecnológica geradora de impactos ambientais positivos

    Stripes and holes in a two-dimensional model of spinless fermions and hardcore bosons

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    We consider a Hubbard-like model of strongly-interacting spinless fermions and hardcore bosons on a square lattice, such that nearest neighbor occupation is forbidden. Stripes (lines of holes across the lattice forming antiphase walls between ordered domains) are a favorable way to dope this system below half-filling. The problem of a single stripe can be mapped to a spin-1/2 chain, which allows understanding of its elementary excitations and calculation of the stripe's effective mass for transverse vibrations. Using Lanczos exact diagonalization, we investigate the excitation gap and dispersion of a hole on a stripe, and the interaction of two holes. We also study the interaction of two, three, and four stripes, finding that they repel, and the interaction energy decays with stripe separation as if they are hardcore particles moving in one (transverse) direction. To determine the stability of an array of stripes against phase separation into particle-rich phase and hole-rich liquid, we evaluate the liquid's equation of state, finding the stripe-array is not stable for bosons but is possibly stable for fermions.Comment: 24 pages, 18 figure
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