LACTEC Institute of Technology for Development

Curitiba, Brazil

LACTEC Institute of Technology for Development

Curitiba, Brazil

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Furtado A.C.,State University of Maringá | Alonso C.G.,State University of Maringá | Cantao M.P.,LACTEC Institute of Technology for Development | Fernandes-Machado N.R.C.,State University of Maringá
International Journal of Hydrogen Energy | Year: 2011

The ethanol oxidative reforming reaction was performed with Ni-Cu catalysts on different supports. The results indicated that Ni-Cu/Nb2O 5 and Ni-Cu/ZnO were the most appropriate catalysts for the reaction regarding activity, stability, and selectivity for hydrogen production. Ni-Cu/Nb2O5 catalysts have strong acidity (at 600 °C), while ZnO has very low acidity. Ni-Cu/Ce0.6Zr0.4O 2 catalysts, which only have weak acidity (at 250 °C), presented poor stability and hydrogen selectivity. This shows that acidity has no influence on hydrogen production. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Mariani V.C.,Pontifical Catholic University of Parana | Duck A.R.K.,Pontifical Catholic University of Parana | Guerra F.A.,LACTEC Institute of Technology for Development | Coelho L.D.S.,Pontifical Catholic University of Parana | Rao R.V.,Sardar Vallabhbhai National Institute of Technology, Surat
Applied Thermal Engineering | Year: 2012

Particle swarm optimization (PSO) method is a population-based optimization technique of swarm intelligence field in which each solution called "particle" flies around in a multidimensional problem search space. During the flight, every particle adjusts its position according to its own experience, as well as the experience of neighboring particles, using the best position encountered by itself and its neighbors. In this paper, a new quantum particle swarm optimization (QPSO) approach combined with Zaslavskii chaotic map sequences (QPSOZ) to shell and tube heat exchanger optimization is presented based on the minimization from economic view point. The results obtained in this paper for two case studies using the proposed QPSOZ approach, are compared with those obtained by using genetic algorithm, PSO and classical QPSO showing the best performance of QPSOZ. In order to verify the capability of the proposed method, two case studies are also presented showing that significant cost reductions are feasible with respect to traditionally designed exchangers. Referring to the literature test cases, reduction of capital investment up to 20% and 6% for the first and second cases, respectively, were obtained. Therefore, the annual pumping cost decreased markedly 72% and 75%, with an overall decrease of total cost up to 30% and 27%, respectively, for the cases 1 and 2, respectively, showing the improvement potential of the proposed method, QPSOZ. © 2011 Elsevier Ltd. All rights reserved.


Coelho L.S.,Pontifical Catholic University of Parana | Coelho L.S.,Federal University of Paraná | Guerra F.,LACTEC Institute of Technology for Development | Batistela N.J.,Federal University of Santa Catarina | Leite J.V.,Federal University of Santa Catarina
IEEE Transactions on Magnetics | Year: 2013

The parameter identification of hysteresis models is a fundamental task for correct hysteretic material simulation. In vector models, as the Jiles-Atherton (J-A) vector model, the parameter determination increases in complexity since one must solve a nonlinear system with a relative large number of variables. In these cases, fitting methods one of the most attractive solution. In this study, an improved multiobjective cuckoo search (IMCS) is introduced for the J-A parameters determination. The proposed IMCS based on the Duffing's oscillator to step size tuning is verified using data from a rotational single sheet tester in two-dimensional version. Numerical comparisons of IMCS with results using a multiobjective cuckoo search demonstrated that the performance of the IMCS is promising in parameters estimation. Furthermore, the proposed IMCS method can be easily extended to solve a wide range of multiobjective optimization problems. © 1965-2012 IEEE.


Dahlke D.B.,Federal University of Paraná | Steilein G.,Federal University of Paraná | Fernandes T.S.P.,Federal University of Paraná | Aoki A.R.,LACTEC Institute of Technology for Development
International Journal of Electrical Power and Energy Systems | Year: 2012

Banks of capacitors (BCs) at distribution systems are used to compensate the reactive energy of the network, reduce electric losses and improve the voltage profile. The planning and operation of BCs includes the determination of ideal allocation of them at the distribution network, defining its type, size and adjustments. Considering that the loads undergo variations during the operation time, fixed decision of input/output of the BCs may not be enough to provide the necessary reactive compensation. Therefore, the main objective of this work is to develop a heuristic to adjust the switching of the automatic BCs. This heuristic uses the results of a Parametric Optimal Power Flow that minimizes the electric losses and controls voltage profile along the feeders of the distribution network. The results are presented using a system of 70 buses. © 2012 Elsevier Ltd. All rights reserved.


Szuvovivski I.,Federal University of Paraná | Szuvovivski I.,LACTEC Institute of Technology for Development | Fernandes T.S.P.,Federal University of Paraná | Aoki A.R.,Federal University of Paraná | Aoki A.R.,LACTEC Institute of Technology for Development
International Journal of Electrical Power and Energy Systems | Year: 2012

The high reactive power level demanded by the distribution systems, the loads growth and consequent increase of system losses introduce variations at the buses voltage magnitudes, which compromise the quality of the supplied electric energy. To assure high quality, some devices such as voltage regulators - VRs and capacitors banks - CBs, are installed to allow effective control of voltage magnitude, reactive power and power factor. The present work proposes a methodology to allocate simultaneously these devices using both Genetic Algorithms - GAs and Optimal Power Flow - OPF. The strategy proposed involves the adoption of GA for the allocation of CBs with specification for the type of bank (fixed or automatic) and the reactive power (kvar), as well as the allocation of VRs with adjustment of their secondary voltage. The OPF is responsible for the solution of the power balance equations, tap adjustments of the VRs that assure the voltage level at their exits according to the voltage level specified by the GA for the diverse load curve and for the attainment of the nominal current of the VRs allocated. © 2012 Elsevier Ltd. All rights reserved.


Sebold J.E.,Federal University of Santa Catarina | Lacerda L.A.,LACTEC Institute of Technology for Development
Journal of the Electrochemical Society | Year: 2016

A new procedure for solving coupled ordinary and partial differential equations systems containing multiple internal interfaces is proposed in this paper. The method has interest in systems that may be encountered in electrochemical problems, more specifically in batteries whose inner regions are composed by liquid and solid juxtaposed subdomains. However, the method application is general. The central contribution of the procedure is a QR factorization algorithm based on modified Householder transformations for block systems. Its application performance is demonstrated with a numerical example, where despite the more ellaborate mathematical algorithm less refined mesh discretizations are necessary for accurate solutions. © 2016 The Electrochemical Society. All rights reserved.


Wilhelm H.M.,LACTEC Institute of Technology for Development | Tulio L.,LACTEC Institute of Technology for Development | Jasinski R.,Companhia Paranaense de Energia | Almeida G.,Companhia Paranaense de Energia
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2011

In this work, the degradation process of natural ester-based insulating fluids was evaluated through laboratory aging tests. Two distinct aging methodologies were used: natural ester-based insulating fluids were placed in sealed flasks at 120 0C in the presence of Kraft insulating paper containing about 1.5 and 5 wt% moisture; and natural ester-based insulating fluids were aged with and without Kraft insulating paper containing 1.5 wt% moisture in an open system, adding oxygen at different temperatures. The results indicate that viscosity, acid number and dissipation factor are important markers to consider in monitoring service-aged natural ester fluids. © 2006 IEEE.


Wilhelm H.M.,LACTEC Institute of Technology for Development | Stocco G.B.,LACTEC Institute of Technology for Development | Batista Jr. S.G.,Companhia Paranaense de Energia
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2013

The degradation of in-service natural ester-based insulating fluid could result in oil viscosity, acidity and dissipation factor increases. In this work, natural ester-based insulating fluid samples aged in the laboratory and in-service (collected from a Recloser) were reclaimed with different adsorbent materials. All the tested samples showed some properties above the provisional limit for triggering prompt additional investigation suggested by the IEEE guide for in-service natural ester fluids, such as viscosity increase > 10% from value at time of initial energization, acid number > 0.3 mg KOH/g or dissipation factor at 25 0C > 3%. The reclamation process was accomplished by the use of two methods: 1) by mechanical agitation of the aged oil in the presence of several adsorbents and 2) by percolation of the aged oil through the adsorbent material. The reclaimed fluids were monitored by evaluation of viscosity, acid number and dissipation factor and the results were compared with unused oil. The results showed that viscosity is the main criterion to evaluate whether or not in-service natural ester-based insulating fluid can be reclaimed. © 1994-2012 IEEE.


Hultmann Ayala H.V.,LACTEC Institute of Technology for Development | Dos Santos Coelho L.,Pontifical Catholic University of Parana
Expert Systems with Applications | Year: 2012

Most controllers optimization and design problems are multiobjective in nature, since they normally have several (possibly conflicting) objectives that must be satisfied at the same time. Instead of aiming at finding a single solution, the multiobjective optimization methods try to produce a set of good trade-off solutions from which the decision maker may select one. Several methods have been devised for solving multiobjective optimization problems in control systems field. Traditionally, classical optimization algorithms based on nonlinear programming or optimal control theories are applied to obtain the solution of such problems. The presence of multiple objectives in a problem usually gives rise to a set of optimal solutions, largely known as Pareto-optimal solutions. Recently, Multiobjective Evolutionary Algorithms (MOEAs) have been applied to control systems problems. Compared with mathematical programming, MOEAs are very suitable to solve multiobjective optimization problems, because they deal simultaneously with a set of solutions and find a number of Pareto optimal solutions in a single run of algorithm. Starting from a set of initial solutions, MOEAs use iteratively improving optimization techniques to find the optimal solutions. In every iterative progress, MOEAs favor population-based Pareto dominance as a measure of fitness. In the MOEAs context, the Non-dominated Sorting Genetic Algorithm (NSGA-II) has been successfully applied to solving many multiobjective problems. This paper presents the design and the tuning of two PID (Proportional-Integral-Derivative) controllers through the NSGA-II approach. Simulation numerical results of multivariable PID control and convergence of the NSGA-II is presented and discussed with application in a robotic manipulator of two-degree-of-freedom. The proposed optimization method based on NSGA-II offers an effective way to implement simple but robust solutions providing a good reference tracking performance in closed loop. © 2012 Elsevier Ltd. All rights reserved.


De Andrade J.,LACTEC Institute of Technology for Development | Impinnisi P.R.,LACTEC Institute of Technology for Development | Do Vale D.L.,LACTEC Institute of Technology for Development
Journal of Power Sources | Year: 2011

Two disadvantages of lead acid batteries are poor power and energy densities and the necessity of relatively long recharging times. In this paper it is presented the results of ongoing work aimed at increasing both the positive active material (PAM) specific capacity and the positive plate charge acceptability. The experimental results show that adequate curing processes can be used to develop an interconnected structure among nanometric PbO 2 particles to produce tubular electrodes with specific capacity higher than 180 Ah kg -1 and maintain this value for 130 cycles with deep discharges. These PbO 2 positive plates are expected to exhibit higher charge acceptability due to their larger PAM surface area as compared to conventional ones, but the results indicate that the high internal ohmic resistance of the grid/PAM zone limits the fast charge efficiency. © 2010 Elsevier B.V. All rights reserved.

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