Institutos Lactec

Curitiba, Brazil

Institutos Lactec

Curitiba, Brazil

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Da Silva G.C.,Institutos Lactec | Munaro M.,Institutos Lactec | Junior S.R.,Institutos Lactec | Araujo D.B.,Institutos Lactec | And 3 more authors.
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference | Year: 2016

Spacer cable system has been widely used in Brazil in low polluted areas such as rural and urban areas. However, Brazilian national standards do not recommend installing spacer cable systems in medium and high polluted areas due to the accelerated aging of the electrical equipment and accessories. In this paper is presented the evaluation of alternatives for the use of spacer cable system in these areas by using new materials on the interface between the covered conductor and the spacer. Other components evaluated were porcelain and polymeric insulators. Besides the standard configuration, different materials were applied on the interface between the cable and the spacer: semiconducting tubes on the cable, autofusion semiconducting tape on the cable and semiconducting tape on the spacer. These materials were submitted to multiple stress tests and its performance were evaluated by visual inspections and leakage current measurements. © 2016 IEEE.

Sucharski G.B.,Federal University of Paraná | Pukasiewicz A.G.M.,Federal Technological University of Paraná | Vaz R.F.,Institutos Lactec | Paredes R.S.C.,Federal University of Paraná
Soldagem e Inspecao | Year: 2015

HVOF thermal spray process produces coatings with low porosity and low oxide content, as well as high substrate adhesion. Small variations on the parameters of the HVOF process can generate coatings with different characteristics and properties, which also is chemical composition depended of the alloy. FeMnCrSi alloy is a cavitation resistant class of material with a great potential for HVOF deposition use. The main goal of this article is to study the influence of some HVOF parameters deposition, as standoff distance, powder feed rate and carrier gas pressure on three different alloys. FeMnCrSi experimental alloys with some variations in nickel and boron content were studied. Taguchi experimental design with L9 orthogonal array was used in this work. Porosity, oxide content, tensile adhesion strength and microhardness of the coatings were evaluated. The results indicated that all factors have significant influence on these properties. Chemical composition of the alloys was the most important factor, followed by the carrier gas pressure, standoff distance and powder feed rate. The addition of Ni, produces coatings with lower levels of oxide content and porosity. An experiment with improved parameters was conducted, and a great improvement on the coating properties was observed. © 2015, Universidade Federal de Uberlandia. All rights reserved.

Souza-Bastos L.R.,Federal University of Paraná | Bastos L.P.,Institutos LACTEC | Carneiro P.C.F.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Freire C.A.,Federal University of Paraná
Aquaculture | Year: 2016

The use of salt in the management and culture of freshwater fishes is a quite common practice, either to fight infection or to possibly reduce the stress of transport, through reduction in the metabolic cost of hyper-regulation. Increased salinity, depending on the salt concentration used and the species, can be in itself a stress factor. This study aimed at evaluating and comparing the physiological effects of exposure to increased salinity in P. mesopotamicus (Pacu), C. macropomum (Tambaqui) and their hybrid (Tambacu), as well as to test the resistance of the hybrid when compared to its two parent species. Fishes (n = 38 each) were submitted to 5, 15, and 25 psu for 1 h. Osmolality, ions, and glucose were assayed in plasma, tissue hydration levels were quantified in gills and muscle, carbonic anhydrase activity (CAA) was assayed in gills and kidneys, and the expression of heat shock proteins (HSP70) was evaluated in muscle. All 3 fishes showed similar disturbance in osmotic homeostasis when exposed to 25 psu; the tambaqui displayed higher glycemia than the other fishes, in 15 and 25 psu. In this salinity the fish showed increased osmolality, Na+, Cl− and Mg2 + concentrations, as well as a reduction in muscle hydration. The tambacu showed lower potassium and higher magnesium in 25 psu than the other fishes. CAA was variably sensitive to salinity in the two species and the hybrid. No effects of salinity on tissue HSP70 expression were observed. Tambacus are similar in robustness to their parent species. The markers investigated showed that the three fishes tolerate exposure for 1 h at 10 psu; this concentration can be used for prophylactic or anesthetic purposes, but should not be exceeded, as it can offer significant homeostatic challenges to these fishes. Statement of relevance Rare studies on the comparative physiology of parent species and their hybrid, with commercial interest. © 2016 Elsevier B.V.

Mazur M.M.,Federal University of Paraná | Braganc M.D'O.G.P.,Federal University of Paraná | Portella K.F.,Federal University of Paraná | Ribeiro S.,Institutos LACTEC | And 3 more authors.
Ceramica | Year: 2016

The mechanical strength and the dielectric properties of ceramic insulators are essential properties to support the electricity distribution networks. However, both the moisture and the pollutant content in the atmosphere may become harmful and cause failures in the power supply by increasing its electrical current leakage. The insulating glazing has high affinity with the resulting water from the interaction of the glass surface with atmosphere. In this study, the deposition of aluminum nitride films was carried out on the glazed samples of ceramic electrical insulators, via pulsed DC magnetron sputtering plasma, and with a mixture of argon and nitrogen gas and Ti on pin type insulators for 15 kV voltage class. The morphology of the films and the performance of insulators were measured by SEM-FEG/EDS, AFM, maximum RMS leakage current and degree of hydrophobicity. The performance of deposited films by the degree of hydrophobicity measured in samples reduced from CM6 to CM4 with AlN, and CM7 to CM3 with Ti layer. The maximum RMS leakage current measured with and without the insulating film based on nanometric Ti was higher in devices without the protection, reaching measured values of 5 mA and with shutdown of computerized measuring system (after 3 days in Sauípe and 3 months in Pituba) as a consequence of having overcome the short circuit withdrawal period laid down in software (surges exceeding 300 mA). With the deposition of the films in 7 insulators, changes in two of these, with peaks of maximum leakage current achieving 2.4 mA, in the field were observed. Most insulators analyzed had the variations in RMS leakage current between 0.2 and 2 mA in the measurement period, in adverse conditions of weather (rain and different wind speeds).

Braganca M.O.G.P.,Federal University of Paraná | Braganca M.O.G.P.,Institutos Lactec | Portella K.F.,Institutos Lactec | Bonato M.M.,Federal University of Paraná | Marino C.E.B.,Federal University of Paraná
Construction and Building Materials | Year: 2014

Samples of reinforced mortar specimens (Sps) were studied over 300 days of exposure in reference, sulfate, and chloride environments. Electrochemical impedance spectroscopy (EIS) was used to investigate external sulfate attack (ESA) in comparison with known chloride models. The study, based on the mortar behavior and its measured electrical properties, highlighted the mechanisms that occur under the pores during the aging. The sulfate samples presented a capacitive behavior at lower frequencies, and the mortar resistance shifted. It was confirmed that EIS is a qualified technique to identify the sulfate attack in concrete by non-destructive methods. © 2014 Elsevier Ltd. All rights reserved.

Freire C.A.,Federal University of Paraná | Souza-Bastos L.R.,Federal University of Paraná | Chiesse J.,Federal University of Paraná | Tincani F.H.,Federal University of Paraná | And 9 more authors.
Environmental Science and Pollution Research | Year: 2015

Iguaçu River is the second most polluted river of Brazil. It receives agrochemicals and contaminants of urban and industrial sources along its course. A multibiomarker approach was employed here to evaluate the health of a small characin (Astyanax spp.) at two sites along the river, sampled during a dry (autumn) and a rainy (spring) season. Biomarkers were condition factor and somatic indices (gonads and liver); genetic damage (comet assay and micronucleus test); enzyme activities such as hepatic catalase (CAT) and glutathione S-transferase (GST), lipoperoxidation (LPO), branchial and renal carbonic anhydrase (CA), acetylcholinesterase (AChE) in the muscle and the brain, histopathology of the liver and gills, and concentrations of polycyclic aromatic hydrocarbons (PAHs) in bile. There were no consistent differences in biomarker responses between the two study sites. Some biomarkers revealed greater potential impact in the rainy season, when increased amounts of contaminants are washed into the river (combined CAT inhibition and LPO increase, CA upregulation). Other biomarkers, however, revealed potential greater impact in the dry season, when contaminants potentially concentrate (GST induction, AChE inhibition, and liver histopathological alterations). Although of a complex nature, field experiments such as this provide rich data for monitoring protocols and assessment of general risk of exposure to pollutants of river systems. © 2015, Springer-Verlag Berlin Heidelberg.

Braganca M.O.G.P.,Federal University of Paraná | Braganca M.O.G.P.,Institutos Lactec | Portella K.F.,Institutos Lactec | Bonato M.M.,Federal University of Paraná | And 2 more authors.
Construction and Building Materials | Year: 2016

Concretes with 1% nano-Fe3O4 addition aged for 300 days in chloride and sulfur dioxide chambers were analyzed by multiple technics and the performance results were evaluated by impedance spectroscopy and cyclic voltammetry. They exhibited a higher electrochemical stability because of the absence of passive film breakdown and an enhanced electrical resistance to charge transfer. The better properties were resulted from a more homogeneous microstructure produced by the byproducts of the reaction between the cement hydrates and the added nano-material. They were supposed be accumulated in pores and voids. © 2016 Published by Elsevier Ltd.

Fernandes N.T.D.,Programa de Pos Graduacao em Desenvolvimento de Tecnologia | Demonti R.,Programa de Pos Graduacao em Desenvolvimento de Tecnologia | Demonti R.,Federal University of Paraná | De Andrade J.,Programa de Pos Graduacao em Desenvolvimento de Tecnologia | And 5 more authors.
2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference, COBEP/SPEC 2016 | Year: 2015

Lead acid batteries are still broadly used in stand alone photovoltaics. The main concerns within the use of this type of batteries are high cycling and the prolonged undervoltage state, which leads to sulfation. This work proposes a method of reverting the battery sulfation and reducing the gases formation using a three-step battery charger. A bidirectional converter in which the output current is pulsed with both magnitude and width controllable is implemented. Those pulses are used together with constant current profiles in order to increase charge acceptance and, by that, reduce the gases formation and potentially increase the battery life. © 2015 IEEE.

Eggea R.F.,Mestrado Profissional Institutos Lactec | Ferreira M.,Mestrado Profissional Institutos Lactec | Aoki A.R.,Institutos Lactec | Riella R.J.,Institutos Lactec
2015 IEEE PES Innovative Smart Grid Technologies Latin America, ISGT LATAM 2015 | Year: 2015

Power systems are undergoing fundamental changes, with emphasis on low-carbon and responsibility on the demand side. This transformation consists on modernization of generation, transmission, distribution and consumer technologies, providing to consumers more participation in managing their energy usage and generation through medias that are part of everyday life, as applications on mobile devices. This paper presents methods for monitoring and controlling the energy consumption and generation using photovoltaic system with energy storage in Smart Grid through a mobile application. It proposes energy consumption's analysis methods, establishment of goal of energy consumption, means to load and storage energy control. The mobile application is presented along with its functional description. Through this application, the costumer may visualize its energy consumption and generation data in a time of use tariff and use this information to support decisions to control its smart plugs and energy storage through schedules. © 2015 IEEE.

Fonseca A.G.,Institutos Lactec | Langner A.L.,Institutos Lactec | Salamanca H.L.L.,Institutos Lactec | Siebert L.C.,Institutos Lactec | And 4 more authors.
2015 IEEE PES Innovative Smart Grid Technologies Latin America, ISGT LATAM 2015 | Year: 2015

This paper presents a case study of a Building Integrated Photovoltaics deployed in a parking lot. Computational models were developed in order to estimate the energy generation, and the usage of batteries for energy management. A developed energy management system, with an algorithm to work with Time-Of-Use tariffs, electric vehicles and storage systems is also described and simulated. The results achieved in a pilot project are also discussed. © 2015 IEEE.

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