Multi-objective energy storage power dispatching using plug-in vehicles in a smart-microgrid

This paper describes a multi-objective power dispatching problem that uses Plug-in Electric Vehicle (PEV) as storage units. We formulate the energy storage planning as a Mixed-Integer Linear Programming (MILP) problem, respecting PEV requirements, minimizing three different objectives and analyzing three different criteria. Two novel cost-to-variability indicators, based on Sharpe Ratio, are introduced for analyzing the volatility of the energy storage schedules. By adding these additional criteria, energy storage planning is optimized seeking to minimize the following: total Microgrid (MG) costs; PEVs batteries usage; maximum peak load; difference between extreme scenarios and two Sharpe Ratio indices. Different scenarios are considered, which are generated with the use of probabilistic forecasting, since prediction involves inherent uncertainty. Energy storage planning scenarios are scheduled according to information provided by lower and upper bounds extracted from probabilistic forecasts. A MicroGrid (MG) scenario composed of two renewable energy resources, a wind energy turbine and photovoltaic cells, a residential MG user and different PEVs is analyzed. Candidate non-dominated solutions are searched from the pool of feasible solutions obtained during different Branch and Bound optimizations. Pareto fronts are discussed and analyzed for different energy storage scenarios. Perhaps the most important conclusion from this study is that schedules that minimize the total system cost may increase maximum peak load and its volatility over different possible scenarios, therefore may be less robust

Baroreflex sensitivity differs among same strain Wistar rats from the same laboratory

Previous studies showed that a proportion of normotensive Sprague-Dawley rats spontaneously exhibit lower baroreflex sensitivity. However, investigations have not yet been carried out on Wistar rats. We aimed to compare baroreflex sensitivity among rats from the same strain and the same laboratory. Male Wistar normotensive rats (300–400g) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure and heart rate. Baroreflex was calculated as the derivative of the variation of heart rate in function of the mean arterial pressure variation (ΔHR/ΔMAP) tested with a depressor dose of sodium nitroprusside (50 µg/kg) and with a pressor dose of phenylephrine (8µg/kg) in the right femoral venous approach through an inserted cannula. We divided the rats into four groups: i) high bradycardic baroreflex, baroreflex gain less than −2 tested with phenylephrine; ii) low bradycardic baroreflex, baroreflex gain between −1 and −2 tested with phenylephrine; iii) high tachycardic baroreflex, baroreflex gain less than −3 tested with sodium nitroprusside; and iv) low tachycardic baroreflex, baroreflex gain between −1 and −3 tested with sodium nitroprusside. Approximately 71% of the rats presented a decrease in bradycardic reflex while around half showed an increase in tachycardic reflex. No significant changes in basal mean arterial pressure and heart rate, tachycardic and bradycardic peak and heart rate range were observed. There was a significant change in baroreflex sensitivity among rats from the same strain and the same laboratory

Nutrição mineral de hortaliças: XXIX. absorção de macronutrientes por quatro cultivares de morangueiro (Fragaria spp.)

The aim of this work was to estimate the differences in growth (dry weight basis), nutrients uptake, fruits yield, total uptake and exportation of nutrients among several strawberry cultivars: Campinas (IAC-2712), Camanducaia (IAC-3530), Monte Alegre (IAC-3113) and SH-2. The experimental was carried out in the Escola Superior de Agricultura "Luiz de Queiroz", in field conditions, in 1975/76. The soil belongs to Terra Roxa Estruturada type, and "Luiz de Queiroz" serie. This soil has been cultivated for more than 25 years. The experimental design was that randomized blocks with four replications and analysed together following the design of split-plot. The soil of the plots were revolved to a deep of 12 cm following application of 10 kg organic matter/m². The fertilizers were applied in the groove and in the same amount for all cultivars: Ammonium sulfate (20% N), 10 g/m; triple superphosphate (20% P(2)0(5)) 10 g/m; Potassium cloride (60% K(2)0), 10 g/m. Therty days after planting, 10 g/plant of ammonium sulfate was applied. After 76 days from planting, the firsa sample was taken. Other samples were taken in equal intervals of 20 days, up to 216 days. When a decrease in fruitproduction was noted. The sample (plants) were divided in stems, leaves and fruits and chemical analysis were made for N, R, K, Ca, Mg e S. The variation on production (dry matter) nutrient uptake' and fruits yield, were obtained from data calculated by adjusted regression equation analysis. The maxima point from these equations were taken to show the total nutrient uptake. From the data obtained, the following conclusions could be drawn. Growth - The dry matter of stems, leaves and fruits were different among the cultivars. The production of dry matter by the stems and fruits were linnear for all cultivars up to 196 and 216 days. The highest productions on dry matter varied between 15 to 25 g and 12 to 20 g/plant. The maximum production of dry matter in the leaves among the cultivars varied between 20 to 30 g at 196 and 173 days respectivelly. The cultivars Campinas (IAC-2712) and Camanducaia (IAC-3530) produced more dry matter than SH-2 cultivar. Nutrient uptake -< The were differences on nutrient content in stems and leaves among cultivars (R, K, Ca, S, B) and in the fruits for N, R, K, Mg, S. The highest absorption of nutrients (days after planting) is shown in Table I. Yield - No significant difference in fruit production was observed among the cultivars. The highest yield among the cultivars showed a variation between 103 to 151 g per plant at the 207 and 207 days,Efetuou-se um estudo para avaliar a absorção e a extração dos macronutrientes nos seguintes cultivares de morangueiro: Campinas (IAC-2712); Camanducaia (IAC-3530) ; Monte Alegre (IAC-3113) e SH-2 em condições de campo. A instalação deu-se em um solo pertencente ao grande grupo Terra Roxa Estruturada, e à série "Luiz de Queiroz" cultivado intensivamente com hortaliças há mais de 25 anos, em Piracicaba-SP. A adubação aplicada foi uniforme para todos os cultivares. São apresentadas as concentrações dos macronutrientes em porcentagem nos seguintes órgãos: caules, folhas e frutos dos cultivares em função da idade (X) em dias. Constatou-se que os cultivares diferem quanto à absorção dos macronutrientes (R, K, Ca e S em relação a caules e folhas, e, N, R, K, Mg e S em relação aos frutos). Constatou-se também que os cultivares extraem totais diferentes de R, K, Ca, Mg e S sendo as extrações de R pelos cultivares menores do que as extrações de Ca e Mg, e no global as de Mg são equivalentes às de S. As quantidades máximas extraídas pelos cultivares para uma população de 150.000 plantas/ha foram : N - 192 kg; R - 24-50 kg; K - 133-244 kg; Ca - 76-116 kg; Mg - 30-34 kg; S - 13-27 kg. - A maior produção de matéria seca tanto nos órgãos como na planta inteira, ocorreu nos cultivares Campinas (IAC-2712) e Camanducaia (IAC-3530) e a menor produção verificou-se no cultivar SH-2. - Os cultivares diferem na absorção dos nutrientes: R, K, Ca, S para caules e folhas. E para frutos, N, R, K, Mg e S. - Os cultivares atingem o máximo da absorção de nutrientes nos órgãos nas seguintes épocas, em dias: - Os cultivares extraem e exportam totais diferentes de R, K, Ca e Mg. - Tanto os macronutrientes são extraídos em quantidades mais elevadas através das folhas e em menor proporção por caules e frutos. - As extrações de N, K e Ca são mais altas que aquelas dos demais macronutrientes. - As extrações de R pelos cultivares são menores que as de Ca e Mg, sendo ainda as extrações de Ca superiores às de Mg, enquanto no global as de Mg são equivalentes às de S. - A extração de macronutrientes verifica-se na ordem decrescente: K, N, Ca, Mg, S e P

Salinomycin and virginiamycin for lactating cows supplemented on pasture

Animals on pasture generally show higher feed efficiency as a result of the use of antibiotics. This study evaluated the effect of the antimicrobials salinomycin and/or virginiamycin on production and the ruminal parameters of supplemented dairy cows grazing on Panicum maximum cv. Tanzania. Twelve Holstein/Zebu multiparous cows were used, distributed in three Latin squares, one for the evaluation of ruminal parameters, and the others for production parameters. Cows on pasture were fed 50 % of their estimated intake with corn silage and concentrate supplements containing salinomycin, virginiamycin or a combination of additives, in doses of 120 and 150 mg kg−1, respectively. There were no differences in milk production and composition, energy and nitrogen balance, dry matter digestibility and feeding behavior. However, salinomycin and virginiamycin each reduced pasture and total dry matter intake by about 14 % and 10 %, with a consequent improvement in feed efficiency