4,671 research outputs found
Improved voltage control of the electric vehicle operating as UPS in smart homes
As a contribution for sustainability, electric vehicles (EVs) are seen
as one of the most effective influences in the transport sector. As complement
to the challenges that entails the EVs integration into the grid considering the
bidirectional operation (grid-to-vehicle and vehicle-to-grid), there are new concepts
associated with the EV operation integrating various benefits for smart
homes. In this sense, this paper proposes an improved voltage control of the EV
operating as uninterruptible power supply (UPS) in smart homes. With the EV
plugged-in into the smart home, it can act as an off-line UPS protecting the
electrical appliances from power grid outages. Throughout the paper, the foremost
advantages of the proposed voltage control strategy are comprehensively
emphasized, establishing a comparison with the classical approach. Aiming to
offer a sinusoidal voltage for linear and nonlinear electrical appliances, a
pulse-width modulation with a multi-loop control scheme is used. A Kalman
filter is used for decreasing significantly the time of detecting power outages
and, consequently, the transition for the UPS mode. The experimental validation
was executed with a bidirectional charger containing a double stage power
conversion (an ac-dc interfacing the grid-side and a dc-dc interfacing the batteries-
side) and a digital stage. The computer simulations and the acquired experimental
results validate the proposed strategy in different conditions of operation.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation – COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT – Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015 – POCI – 01–0145–FEDER–016434. This work is part of the FCT project 0302836 NORTE-01-0145-FEDER-030283.info:eu-repo/semantics/publishedVersio
DiagnĂłstico de mastite subclĂnica caprina por meio da detecção de Staphylococcus aureus utilizando a tĂ©cnica de RT-PCR.
A presente publicação descreve os procedimentos necessários para a identificação e confirmação molecular de estirpes de S. aureus causadoras de mastite subclĂnica, provenientes de amostras de leite de cabra, por meio da tĂ©cnica de RT-PCR.bitstream/item/144724/1/CNPC-2015-Diagnostico-de-mastite.pd
Optomechanical cooling of levitated spheres with doubly-resonant fields
Optomechanical cooling of levitated dielectric particles represents a
promising new approach in the quest to cool small mechanical resonators towards
their quantum ground state. We investigate two-mode cooling of levitated
nanospheres in a self-trapping regime. We identify a rich structure of split
sidebands (by a mechanism unrelated to usual strong-coupling effects) and
strong cooling even when one mode is blue detuned. We show the best regimes
occur when both optical fields cooperatively cool and trap the nanosphere,
where cooling rates are over an order of magnitude faster compared to
corresponding single-sideband cooling rates.Comment: 8 Pages, 7 figure
The electric vehicle in smart homes: a review and future perspectives
The electric mobility dissemination is forcing the adoption of new technologies and operation paradigms, not only focusing on smart grids, but also on smart homes. In fact, the emerging technologies for smart homes are also altering the conventional grids toward smart grids. By combining the key pillars of electric mobility and smart homes, this paper characterizes the paradigms of the electric vehicle (EV) in smart homes, presenting a review about the state of the art and establishing a relation with future perspectives. Since the smart home must be prepared to deal with the necessities of the EV, the analysis of both on board and off board battery charging systems are considered in the paper. Moreover, the in-clusion of renewable energy sources, energy storage systems, and dc electrical appliances in smart homes towards sustainability is also considered in this paper, but framed in the perspective of an EV off board battery charging system. As a pertinent contribution, this paper offers future perspectives for the EV in smart homes, including the possibility of ac, dc, and hybrid smart homes. Covering all of these aspects, exemplificative and key results are presented based on numerical simulations and experimental results obtained with a proof of concept prototype.FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FC
Shell we cook it? An experimental approach to the microarchaeological record of shellfish roasting
In this paper, we investigate the microarchaeological traces and archaeological visibility of shellfish cooking activities through a series of experimental procedures with direct roasting using wood-fueled fires and controlled heating in a muffle furnace. An interdisciplinary geoarchaeological approach, combining micromorphology, FTIR (in transmission and ATR collection modes), TGA and XRD, was used to establish a baseline on the mineralogical transformation of heated shells from aragonite to calcite and diagnostic sedimentary traces produced by roasting fire features. Our experimental design focused on three main types of roasting procedures: the construction of shallow depressions with heated rocks (pebble cuvette experiments), placing shellfish on top of hot embers and ashes (fire below experiment), and by kindling short-lived fires on top of shellfish (fire above experiments). Our results suggest that similar shellfish roasting procedures will largely create microstratigraphic signatures of anthropogenically reworked combusted material spatially “disconnected” from the actual combustion locus. The construction of shallow earth ovens might entail an increased archaeological visibility, and some diagnostic signatures of in situ hearths can be obtained by fire below roasting activities. We also show that macroscopic visual modifications and mineralogical characterization of discarded shellfish might be indicative of specific cooking activities versus secondary burning
Research Notes : Brazil : Varietal differences in soybeans for resistance to physical damage of seed
Introduction: Production of quality soybean seed is frequently problematic in the tropics (Jalani et al., 1982; Khaleque, 1982; Mercer-Quarshie and Nsowah, 1975; Ndimande et al., 1981; Paschal and Ellis, 1978). In general, loss of seed vigor is associated with seed deterioration in the field prior to harvest (Ellis and Sinclair, 1976; Green and Finnel, 1968; Ndimande et al., 1981; Paschal and Ellis, 1978; Potts et al., 1978) and with deterioration in storage (Kueneman, 1982; Minor and Paschal, 1982; Ndimande et al., 1981; Tongdee, 1982; Wien and Kueneman, 1981); seed deterioration is accelerated by hot, humid environments. While there is considerable scope for development of genotypes less prone to deterioration (Dassou and Kueneman, 1984; Kueneman, 1982, 1983; Paschal and Ellis, 1978; Wien and Kueneman, 1981), it is generally recommended that soybeans grown for seed should be sown such that they mature under dry environmental conditions. Often in the tropics, seed production must take place in the dry off-season under irrigation, which increases costs of production
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