Optimized allocation of sectionalizing switches and control and protection devices for reliability indices improvement in distribution systems

Reliability of power supply is related, among other factors, to the control and protection devices allocation in feeders of distribution systems. In this way, optimized allocation of sectionalizing switches and protection devices in strategic points of distribution circuits, improves the quality of power supply and the system reliability indices. In this work, it is presented a mixed integer non-linear programming (MINLP) model, with real and binary variables, for the sectionalizing switches and protection devices allocation problem, in strategic sectors, aimed at improving reliability indices, increasing the utilities billing and fulfilling exigencies of regulatory agencies for the power supply. Optimized allocation of protection devices and switches for restoration, allows that those faulted sectors of the system can be isolated and repaired, re-managing loads of the analyzed feeder into the set of neighbor feeders. Proposed solution technique is a Genetic Algorithm (GA) developed exploiting the physical characteristics of the problem. Results obtained through simulations for a real-life circuit, are presented. © 2004 IEEE.

Lower-semicontinuity and optimization of convex functionals

The result that we treat in this article allows to the utilization of classic tools of convex analysis in the study of optimality conditions in the optimal control convex process for a Volterra-Stietjes linear integral equation in the Banach space G([a, b],X) of the regulated functions in [a, b], that is, the functions f : [a, 6] → X that have only descontinuity of first kind, in Dushnik (or interior) sense, and with an equality linear restriction. In this work we introduce a convex functional Lβf(x) of Nemytskii type, and we present conditions for its lower-semicontinuity. As consequence, Weierstrass Theorem garantees (under compacity conditions) the existence of solution to the problem min{Lβf(x)}. © 2009 Academic Publications.

Aminophylline affects glycemia control and increases anaerobic glycolysis in horses during incremental exercise

A study was conducted on the effects of acute administration of aminophylline on physiological variables in purebred Arabian horses submitted to incremental exercise test. Twelve horses were submitted to two physical tests separated by a 10-day interval in a crossover study. These horses were divided into two groups: control (C, n = 12) and aminophylline (AM, n = 12). The drug at 10 mg/kg body weight or saline was given intravenously, 30 minutes before the incremental exercise test. The treadmill exercise test consisted of an initial warmup followed by gradually increasing physical exigency. Blood samples were assayed for lactic acid, glucose, and insulin. Maximal lactic acidemia was greater (P = .0238) in the AM group. Both V-2 and V-4 (velocities at which lactate concentrations were 2 and 4 mmol/ L, respectively) were reduced in the AM group by 15.85% (P = .0402) and 17.76% (P = .0 109), respectively. At rest as well as at 4 minutes, insulinemia was greater in the AM group (P = .0417 and .0393), Glycemia group at times 8 was statistically lower in the Al (P = .0138) and 10 minutes (P = .0432). Use of ammophylline in horses during incremental exercise does not seem to be beneficial, because this drug has a tendency to cause hypoglycemia and to increase dependence on anaerobic glucose metabolism.

The autonomic control and functional significance of the changes in heart rate associated with air breathing in the jeju, Hoplerythrinus unitaeniatus

The jeju is a teleost fish with bimodal respiration that utilizes a modified swim bladder as an air-breathing organ (ABO). Like all air-breathing fish studied to date, jeju exhibit pronounced changes in heart rate (f(H)) during air-breathing events, and it is believed that these may facilitate oxygen uptake (M-O2) from the ABO. The current study employed power spectral analysis (PSA) of f(H) patterns, coupled with instantaneous respirometry, to investigate the autonomic control of these phenomena and their functional significance for the efficacy of air breathing. The jeju obtained less than 5% of total M-O2 (M-tO2) from air breathing in normoxia at 26 degrees C, and PSA of beat-to-beat variability in fH revealed a pattern similar to that of unimodal water-breathing fish. In deep aquatic hypoxia (water P-O2=1 kPa) the jeju increased the frequency of air breathing (f(AB)) tenfold and maintained M-tO2 unchanged from normoxia. This was associated with a significant increase in heart rate variability (HRV), each air breath (AB) being preceded by a brief bradycardia and then followed by a brief tachycardia. These f(H) changes are qualitatively similar to those associated with breathing in unimodal air-breathing vertebrates. Within 20 heartbeats after the AB, however, a beat-to-beat variability in f(H) typical of water-breathing fish was re-established. Pharmacological blockade revealed that both adrenergic and cholinergic tone increased simultaneously prior to each AB, and then decreased after it. However, modulation of inhibitory cholinergic tone was responsible for the major proportion of HRV, including the precise beat-to-beat modulation of f(H) around each AB. Pharmacological blockade of all variations in f(H) associated with air breathing in deep hypoxia did not, however, have a significant effect upon f(AB) or the regulation of M-tO2. Thus, the functional significance of the profound HRV during air breathing remains a mystery.

Different timing of whitefly control and soybean yield

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Postural control and functional balance in individuals with diabetic peripheral neuropathy

A Neuropatia diabética periférica (NDP) cursa com redução somatossensitiva que pode levar a alterações no controle postural. O objetivo do estudo foi avaliar o controle postural na postura ereta, em diferentes condições, e o equilíbrio funcional em indivíduos com NDP, correlacionar os resultados obtidos na avaliação do controle postural com os valores do teste do equilíbrio funcional e comparar os resultados obtidos no grupo neuropata com o grupo controle, verificando as possíveis diferenças entre as condições de avaliação em ambos os grupos. Participaram do estudo 13 mulheres com NDP (GN) e 17 mulheres não diabéticas (GC). A avaliação do controle postural foi realizada por cinemetria nas condições: olhos abertos (OA), olhos fechados (OF) e semi tandem (ST). Após processamento no MATLAB, foram geradas as variáveis: amplitude média de oscilação (AMO) na direção ântero-posterior (AP) e médio-lateral (ML); e velocidade média de oscilação (VMO) na direção AP e ML. O equilíbrio funcional foi avaliado pelo Timed Up and Go Test. Houve diferença significante entre os grupos (p<0,005) na AMO-AP OA e OF, AMO-ML of e ST e VMO-ML ST. Houve diferença entre as condições OA e ST (p<0,005) e of e ST (p<0,005) para as variáveis AMO-ML e VMO-ML, com maior prejuízo para o GN, que também apresentou um menor equilíbrio funcional (p=0,001). A instabilidade ML foi correlacionada positivamente com o desequilíbrio funcional. Os resultados nos mostram uma alteração no sistema de controle postural na NDP, o que pode levar estes indivíduos a um maior risco a quedas e prejuízos funcionais.

Fast optical preparation, control, and readout of a single quantum dot spin

We propose and demonstrate the sequential initialization, optical control, and readout of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole pair. Optical control is observed as a coherent Rabi rotation between the hole and charged-exciton states, which is conditional on the initial hole spin state. The spin-selective creation of the charged exciton provides a photocurrent readout of the hole spin state.

Optimised placement of control and protective devices in electric distribution systems through reactive tabu search algorithm

Optimised placement of control and protective devices in distribution networks allows for a better operation and improvement of the reliability indices of the system. Control devices (used to reconfigure the feeders) are placed in distribution networks to obtain an optimal operation strategy to facilitate power supply restoration in the case of a contingency. Protective devices (used to isolate faults) are placed in distribution systems to improve the reliability and continuity of the power supply, significantly reducing the impacts that a fault can have in terms of customer outages, and the time needed for fault location and system restoration. This paper presents a novel technique to optimally place both control and protective devices in the same optimisation process on radial distribution feeders. The problem is modelled through mixed integer non-linear programming (MINLP) with real and binary variables. The reactive tabu search algorithm (RTS) is proposed to solve this problem. Results and optimised strategies for placing control and protective devices considering a practical feeder are presented. (c) 2007 Elsevier B.V. All rights reserved.

Optimal design of smart structures using bonded plezoelectrics for vibration control

Smart material technology has become an area of increasing interest for the development of lighter and stronger structures which are able to incorporate actuator and sensor capabilities for collocated control. In the design of actively controlled structures, the determination of the actuator locations and the controller gains, is a very important issue. For that purpose, smart material modelling, modal analysis methods, control and optimization techniques are the most important ingredients to be taken into account. The optimization problem to be solved in this context presents two interdependent aspects. The first one is related to the discrete optimal actuator location selection problem which is solved in this paper using genetic algorithms. The second is represented by a continuous variable optimization problem, through which the control gains are determined using classical techniques. A cantilever Euler-Bernoulli beam is used to illustrate the presented methodology.

Optimal placement of piezoelectric sensor/actuators for smart structures vibration control

Smart material technology has become an area of increasing interest for the development of lighter and stronger structures that are able to incorporate actuator and sensor capabilities for collocated control. In the design of actively controlled structures, the determination of the actuator locations and the controller gains is a very important issue. For that purpose, smart material modeling, modal analysis methods, and control and optimization techniques are the most important ingredients to be taken into account. The optimization problem to be solved in this context presents two interdependent aspects. The first is related to the discrete optimal actuator location selection problem, which is solved in this paper using genetic algorithms. The second is represented by a continuous variable optimization problem, through which the control gains are determined using classical techniques. A cantilever Euler-Bernoulli beam is used to illustrate the presented methodology.

Finite Element Modeling for Development and Optimization of a Bone Plate for Mandibular Fracture in Dogs

This study aimed to develop a plate to treat fractures of the mandibular body in dogs and to validate the project using finite elements and biomechanical essays. Mandible prototypes were produced with 10 oblique ventrorostral fractures (favorable) and 10 oblique ventrocaudal fractures (unfavorable). Three groups were established for each fracture type. Osteosynthesis with a pure titanium plate of double-arch geometry and blocked monocortical screws offree angulanon were used. The mechanical resistance of the prototype with unfavorable fracture was lower than that of the fcworable fracture. In both fractures, the deflection increased and the relative stiffness decreased proportionally to the diminishing screw number The finite element analysis validated this plate study, since the maximum tension concentration observed on the plate was lower than the resistance limit tension admitted by the titanium. In conclusion, the double-arch geometry plate fixed with blocked monocortical screws has sufficient resistance to stabilize oblique,fractures, without compromising mandibular dental or neurovascular structures. J Vet Dent 24 (7); 212 - 221, 2010

alpha(1)-Adrenoceptors in proximal segments of tail arteries from control and reserpinised rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)