717 research outputs found

    An intelligent home automation control system based on A novel heat pump and wireless sensor networks

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    One of technology's main goals is to providing comfort to humans. However, in order to be an aid, it has to be easy to install, use and maintain. The ever growing complexity of technological systems can only be achieved by converging different technologies. This is usually expressed as Cyber-Physical Systems (CPS), previews the symbiosis of several technologies in order to make them more accessible. This paper attempts to demonstrate the integration between two technologies such as: Heat-pump System and Wireless Sensor Network (WSN) to provide a new control mechanism for new building generations so-called smart houses. The proposed control architecture benefits from our developed WSN hardware platform. It enables the user to control and monitor the ventilation system using our developed mobile application and/or a personal computer. Also, the performance of the proposed hardware platform is measured in three different environments in order to observer the coverage area of the WSN.Tiago Gomes is supported by FCT, the Portuguese Foundation for Science and Technology (grant SFRH/BD/90162/2012). This work is supported by FEDER through COMPETE and national funds through FCT - Foundation for Science and Technology in the framework of the project FCOMP-OI-0124-FEDER-022674

    Current status of the whitefly Aleurodicus dispersus as an invasive pest in the CapeVerte Islands

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    In the last three decades, the spiralling whitefly (Aleurodicus dispersus) has become an important international pest. The movement of plants and parts of plants (such as fruits) in international trade and tourism, and by natural dispersal, has favoured its introduction to new areas. In common with others whiteflies of economic importance, the immature and adult stages cause direct feeding damage by piercing and sucking of sap from foliage, and indirect damage following the accumulation all over host plants of honeydew and waxy flocculent material produced by the insects. Spiralling whitefly is a pest of tropical and subtropical crops, and highly polyphagous. Up to the 1970s, it had been recorded on 44 genera of plants, belonging to 26 botanical families (Mound & Halsey, 1978). This situation changed with the dispersal of the pest to new areas. Nowadays, the spiralling whitefly is one of the major pest of vegetable, ornamental and fruit crops around the globe (Lambkin, 1999). Important host crops include: banana (Musa sapientum), Citrus spp., coconut (Cocos nocifera), eggplant (Solanum melanogena), guava (Psidium guajava), Hibiscus rosa sinensis, Indian almond (Terminalia catappa), papya (Carica papaya), Rosa sp. and tomato (Lycopersicon esculentum) (Saminathan & Jayaraj, 2001). Spiralling whitefly has its origin in the tropical Americas, including Brazil. Although the pest has been recorded only once in Brasil, in the 1920s in the state of Bahia (Bondar, 1923), it now has official quarantine status because of its economic importance. In the Cape Verte Islands, on the West African coast, the pest was initially introduced in the first half of 2000; it has since become established, reaching urban, natural and agricultural areas of the islands that constitute the archipelago. Since then, the pest has been causing damage to many native plants, ornamentals and cultivated food crops (Anon., 2001; Monteiro, 2004). The present study was done in order to produce an inventory of the most common host plants of spiralling whitefly in this new habitat

    Effect of pre-treatment on açaí pulp microfiltration process.

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    Açaí (Euterpe oleracea Mart.) is a palm tree from north region of Brazil. Its small fruit is rich in bioactive compounds making it an attractive product. The aim of this work was to evaluate the effect of pre-treatments on microfiltration of açaí pulp. Raw material was acaí pulp from Belém, Brazil. Pre-treatments were centrifugation, conducted in a basket centrifuge; refining, in a depulper with a 0.5 ?m mesh; and enzymatic hydrolysis with DSM Rapidase and Picantase for 30 min at 35oC. Microfiltration was conducted in tubular membranes with 0.1?m pore size and 0.022m2 of surface. Processes were carried out at 35oC/3bar in batch mode. Permeate flux was determined during the process. Total and soluble solids, pH and acidity were determined on initial and treated pulp, permeate and retentate. Initial pulp contained 13.89 (w/w), 2.85oBrix, 0.19g/100g (malic acid) and 4.93 of pH. Total solids of treated pulp from centrifugation (5.71%) were lower than the others (13.83 and 13.84%) which consequently caused lower total solids in retentate and permeate fractions. Acidity and pH of treated pulp were different (p<0.05) for the different pre-treatments. Similar behaviors were also verified to retentate and permeate fractions. Values varied from 0.10 to 0.29 g/100g malic acid and pH from 4.17 to 4.98, with no correlation to total solids content. Soluble solids were different for each fraction although there was no significant difference in the same fraction in function of used pre-treatment. The values were 2.87, 1.63 and 4.77oBrix for treated pulp, permeate and retentate, respectively. Average flux was affected by pre-treatment being the lowest values, around 70 L/hm2, obtained after centrifugation and the highest, 110 L/hm2, with the enzymatic action. As physical-chemical parameters did not present a behavior that contributes for the pre-treatment selection, permeate flux results suggest the use of enzyme as the recommended option

    Evidence that the insertion events of IS2 transposition are biased towards abrupt compositional shifts in target DNA and modulated by a diverse set of culture parameters

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    Insertion specificity of mobile genetic elements is a rather complex aspect of DNA transposition, which, despite much progress towards its elucidation, still remains incompletely understood. We report here the results of a meta-analysis of IS2 target sites from genomic, phage, and plasmid DNA and find that newly acquired IS2 elements are consistently inserted around abrupt DNA compositional shifts, particularly in the form of switch sites of GC skew. The results presented in this study not only corroborate our previous observations that both the insertion sequence (IS) minicircle junction and target region adopt intrinsically bent conformations in IS2, but most interestingly, extend this requirement to other families of IS elements. Using this information, we were able to pinpoint regions with high propensity for transposition and to predict and detect, de novo, a novel IS2 insertion event in the 3′ region of the gfp gene of a reporter plasmid. We also found that during amplification of this plasmid, process parameters such as scale, culture growth phase, and medium composition exacerbate IS2 transposition, leading to contamination levels with potentially detrimental clinical effects. Overall, our findings provide new insights into the role of target DNA structure in the mechanism of transposition of IS elements and extend our understanding of how culture conditions are a relevant factor in the induction of genetic instability.Fundação para a Ciência e a Tecnologia (PTDC/EBB-EBI/113650/2009)MIT-Portugal Progra

    Model predictive current control of a slow battery charger for electric mobility applications

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    This paper presents a model predictive current control applied to a slow electric vehicle (EV) battery charger. Taking into account the similarities between the power converters inside the EV, it is possible to combine the battery charger and the motor driver in a single integrated converter, thus reducing the weight and volume of the proposed solution, and also contributing to reduce the final price of the EV. Due to the bidirectional power flow capability of the integrated power converter, when working as a slow EV battery charger it can operate in grid-to-vehicle (G2V) mode and in vehicle-to-grid (V2G) mode, contributing to make EVs an important assets in the future smart grids. The integrated power converter working as battery charger operates with sinusoidal current and unitary power factor, contributing to improve the power quality of the electrical grid. This paper provides simulation and experimental results that validate the model predictive control algorithm applied to the proposed integrated power converter working as slow EV battery charger.(undefined)info:eu-repo/semantics/publishedVersio

    Synergistic potential of dillapiole oil for synthetic pyrethroid insecticides against the fall armyworm.

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    Spodoptera frugiperda (J.E. Smith) is a serious lepidopterous pest of several economically important crops. Control of the fall armyworm has depended exclusively on insecticides. As a result, this pest has developed resistance to major classes of insecticides. There has been mounting interest in the use of synergist to reduce this resistance by combined application of insecticide with synergists. A highly effective, expensive insecticide might be used at a diluted rate with a less expensive chemical to give satisfactory control of a target insect and minimize the contamination of agro ecosystem

    Synergistic potential of dillapiole-rich essential oil with synthetic pyrethroid insecticides against fall armyworm.

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    The objective of this study was to evaluate the synergy and response homogeneity of the Spodoptera frugiperda larvae population to the Piper aduncum essential oil in combination with pyrethroid insecticides (alpha-cypermethrin, beta-cypermethrin, fenpropathrin, and gamma-cyhalothrin) compared to piperonylbutoxide (PBO) as positive control. Synergism (SF) comparisons were obtained using lethal concentration (LC50) and lethal dose (LD50) ratios of insecticides individually and in their respective synergistic combinations with essential oil and PBO. Dose/concentration-mortality slope curves were used to establish relative toxicity increase promoted by synergism. They also determined homogeneity response. Residual contact revealed significant potentiation for commercial insecticides formulated with beta-cypermethrin (SF=9.05-0.5) and fenpropathrin (SF=34.05-49.77) when combined with the P. aduncum essential oil. For topical contact, significant potentiation occurred only for alpha-cypermethrin (SF=7.55-3.68), fenpropathrin (SF=3.37-1.21), and gamma-cyhalothrin (SF=5.79-10.48) insecticides when combined with essential oil. With the exception of fenpropathrin and gamma-cyhalothrin, insecticides synergistic combinations presented homogeneous response by topical as well as residual contact at least with essential oil. The SF significance values of the P. aduncum essential oil combined with alpha-cypermethrin, beta-cypermethrin, fenpropathrin, and gamma-cyhalothrin insecticides indicated potential for this oil to be used as an alternative to PBO

    Uso de protocolos curtos para indução de estro em ovelhas Santa Inês.

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    A ovinocultura tem crescido substancialmente nos últimos anos. As ovelhas são poliéstricas estacionais de dias curtos, ou seja, dependendo da latitude, obtém-se apenas um parto por ano. Assim, existem algumas técnicas que estão sendo implementadas para otimizar a eficiência reprodutiva nesses animais. A progesterona e progestágenos são os fármacos mais empregados nos programas de sincronização do estro ovino e, na maioria das vezes, associados ao eCG (Gordon, 1997). Este estudo comparou a eficácia de dois protocolos de indução de estro em ovelhas com o objetivo de serem implementados em programas de inseminação artificial em tempo fixo (IATF) em ovinos. [Use of short-term protocols to estrous induction in Santa Inês ewes]
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