Cocal do Sul, Brazil
Cocal do Sul, Brazil

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Ivanova Y.A.,University of Aveiro | Monteiro J.F.,University of Aveiro | Teixeira L.B.,University of Aveiro | Teixeira L.B.,Centro Universitario Barriga Verde | And 3 more authors.
Materials and Design | Year: 2017

This work proposes a new approach for electrochemical reduction of hematite to magnetite and/or metallic iron, based on ceramic cathodes with designed microstructures. The processing method, involving emulsification of concentrated aqueous ceramic suspensions with melted paraffin, enables preparation of cellular hematite ceramics possessing open porosity and pore interconnectivity controlled by simple process parameters. The obtained porous hematite ceramics were successfully used as cathodes for in situ electrochemical reduction in aqueous alkaline electrolyte. Electrochemical reduction converts the designed ceramic microstructure to corresponding cellular Fe/Fe3O4/Fe2O3 composites with adjustable phase distributions and high prospects for applications in heterogeneous catalysis or other applications, based on unique combinations of active functionalities of metallic Fe, magnetite and hematite. © 2017 Elsevier Ltd


Fernandes J.P.,Federal University of Santa Catarina | Duarte G.W.,Federal University of Santa Catarina | Duarte G.W.,Centro Universitario Barriga Verde | Caldart C.,University of the Extreme South of Santa Catarina | And 5 more authors.
Journal of Alloys and Compounds | Year: 2015

Specialized ceramics are manufactured under special conditions and contain specific elements. They possess unique electrical and thermal properties and are frequently used by the electronics industry. Ceramics containing neodymium-barium-copper (NBC) exhibit high conductivities at low temperatures. NBC-based ceramics are typically combined with oxides, i.e., NBCo produced from neodymium oxide, barium oxide and copper oxide. This study presents NBC ceramics that were produced with barium carbonate, copper oxide and neodymium oxide (NBCa) as starting materials. These ceramics have good electrical conductivities at room temperature. Their conductivities are temperature dependent and related to the starting amount of barium carbonate (w%). © 2015 Elsevier B.V. All rights reserved.


Nandi V.S.,Federal University of Santa Catarina | Nandi V.S.,Centro Universitario Barriga Verde | Raupp-Pereira F.,Federal University of Santa Catarina | Montedo O.R.K.,University of the Extreme South of Santa Catarina | Oliveira A.P.N.,Federal University of Santa Catarina
Journal of Cleaner Production | Year: 2015

The aim of this work was the valorization of two wastes that are classified as Class I according to the Brazilian Standard ABNT NBR 10004:2004 in order to obtain a ceramic engobe for the production of single-fire ceramic tiles. Ceramic sludge from a wastewater treatment plant of a ceramic tile manufacturer and recycled glass were used to obtain a frit in order to make the sludge and glass inert in a vitreous matrix. Thus, a representative amount of the ceramic sludge was collected, dried, and characterized by chemical analysis, X-ray diffractometry, and thermal analyses (differential thermal analysis, thermogravimetric analysis, and dilatometric analysis). Furthermore, the ceramic sludge was assessed according to the ABNT NBR 10004:2004. Seven formulations containing ceramic sludge contents varying from 20 to 80 wt% and recycled glass contents varying from 12 to 48 wt% and using calcite, dolomite, ulexite, and saltpeter as raw materials were prepared. Each formulation was melted in a laboratory kiln using alumina crucibles at 1420 °C for 1 h, and the melts were poured into water at room temperature to produce frits. Each frit was milled, and the coefficient of thermal expansion was determined by dilatometry. The results show that the studied ceramic sludge presented high contents of barium and fluoride. The main identified crystalline phases were α-quartz, zircon, illite, and barium silicate. The coefficient of thermal expansion after heat treatment was 5.6 × 10-6 °C-1. Once characterized, the feasibility of applying these wastes as raw materials for the production of ceramic frits was evaluated. The results of the dilatometric analysis, glaze fluidity flow test, and visual analysis showed that the incorporation of these wastes would allow for the obtainment of ceramic frits for producing ceramic engobes. Thus, three formulations of engobe were prepared and heat-treated at 1150, 1165, and 1175 °C. The engobes were characterized (XRD, determination of brightness, colorimetry, and microstructural analysis by optical microscopy) and showed suitable properties for use in the production of ceramic tiles. Engobe E3, which presented the highest ceramic sludge content, was selected for an industrial test. The results of a visual analysis and water spot test showed that the investigated engobe, compared with a commercial engobe (engobe reference), could be used in the production of glazed ceramic tiles. © 2014 Elsevier Ltd.


Piva R.H.,Centro Universitario Barriga Verde | Vilarinho P.,University of Aveiro | Morelli M.R.,Federal University of São Carlos | Fiori M.A.,University of the Extreme South of Santa Catarina | Montedo O.R.K.,University of the Extreme South of Santa Catarina
Ceramics International | Year: 2013

Due to the increasing availability of substitute materials for electrical porcelain, research is needed to adapt formulations involving these materials to the current economic realities of the industry. This study assessed the effect of iron oxide concentration (0, 1, 2, 3, 5, and 8 wt%) on the dielectric properties of an aluminous porcelain composition commonly employed for electrical insulation based on different values of temperature and frequency. Samples with iron oxide contents of 0, 3, and 5 wt% were analyzed using dilatometry, X-ray diffraction, and scanning electron microscopy to evaluate the thermal, structural, and microstructural changes related to their Fe 2O3 concentrations. Both the dielectric constant (εr) and the loss tangent (tan δ) were measured and evaluated in every sample. Results indicated that the presence of Fe 2O3 increased the dielectric constant and loss tangent, which could result in an increase in heating by dielectric losses. Fe 2O3 contents of up to 5 wt% had no significant effect on the performance of these insulators at room temperature (∼30° C) and a high frequency (1 MHz), especially when the hematite phase was completely solubilized in the porcelain phases. © 2013 Elsevier Ltd and Techna Group S.r.l.


Colome L.M.,UniRitter Laureate International Universities | Kunert Filho H.C.,Centro Universitario Barriga Verde | Feranti J.P.S.,Federal University of Santa Maria | dos Santos F.R.,Federal University of Rio Grande do Sul | And 2 more authors.
Ciencia Rural | Year: 2014

This paper describes a case of laparoscopic-assisted ovariohysterectomy in a female cat presenting pyometra and mammary fibroadenomatous hyperplasia. Using four portals, mesovarium were ligated by titanium ligature clips whereas the uterine vessels were occluded by video-assisted conventional ligatures. There were no postoperative complications. Video-assisted technique can be an alternative method for treatment of pyometra and cystic endometrial hyperplasia in female cats.


Kniess C.T.,Nove de Julho University | Kniess C.T.,Federal University of Santa Catarina | Martins G.J.M.,Federal University of Santa Catarina | Martins G.J.M.,Centro Universitario Barriga Verde | And 5 more authors.
Materials Science Forum | Year: 2015

The production of materials from crystallization of glass, called glassceramic, have proved interesting by the possibility of development of different microstructures, with reduced grain size and the presence of residual amorphous phase in different quantities. The method that uses the differential thermal analysis (DTA) provides research on the material properties over a wide temperature range, it´s widely applied to crystallization processes of glassceramic materials. Within this context, this paper aims to study the kinetics of nucleation and crystal growth in glassceramic materials in the system SiO2-Al2O3-Li2O, obtained with the addition of mineral coal bottom ash as source of aluminosilicates, through the technique of differential thermal analysis. © (2015) Trans Tech Publications, Switzerland.


Martins G.J.,Federal University of Santa Catarina | Martins G.J.,Centro Universitario Barriga Verde | Piva D.H.,Centro Universitario Barriga Verde | Mantas P.Q.,University of Aveiro | And 5 more authors.
Materials Science Forum | Year: 2015

The porcelain materials are composed of crystalline particles immersed in a vitreous matrix. This study has aimed to calculate the porcelain’s vitreous phase viscosity through the Vogel-Fucher-Tamman equation, VFT, to obtain eventually curved coating. We’ve formulated a standard mass, and over it we’ve added the proportions of 4, 8 and 15% of sodium feldspar, main former of the liquid phase, in order to verify its influence over the viscosity at the final vitreous phase. Concerning the standard mass, the addition of 4 and 8% has provoked a reduction of viscosity, while the addition of 15% resulted in a rise of viscosity. Because porcelain does not present a homogenous vitreous phase and crystalline particles, the VFT equation may have given us relative viscosity values. However, these values are coherent with glasses containing sodium, if one assumes that the crystalline phases have no influence over the system and that the vitreous phase has a homogenous composition. © (2015) Trans Tech Publications, Switzerland.


Cruz F.B.,Santa Catarina State University | Cruz F.B.,Centro Universitario Barriga Verde | Lohn L.,Santa Catarina State University | Marinho L.S.R.,Santa Catarina State University | And 6 more authors.
Animal Reproduction Science | Year: 2011

Bull breeding soundness evaluation (BBSE) usually neglects the libido and mating ability evaluation. The internal artificial vagina (IAV) permits semen sampling, as well as mating ability evaluation. Few studies have been performed using IAV with young bulls and there are none with Bos indicus bulls. The present study evaluated sexual behavior, mating ability and semen quality in young Bos taurus (Devon) and B. indicus (Nellore) bulls using the IAV device. In the first experiment, 52 Devon bulls, 18-25 months old were observed, and the behavior and mating ability recorded over a 10-min period within a restrained mount-cow with an IAV inserted. In the second experiment, 20 Nellore bulls, 20-30 months old were evaluated over a 20. min period. Of the 52 Devon bulls, 45 (86.5%) had semen recovered with the IAV, 31 (69.0%) were considered satisfactory. Nellore bulls exhibited a different sexual behavior, with 10 bulls not showing any interest in the females. Four bulls demonstrated sexual interest only once, e.g., sniffing, two showed interest on more than one occasion, and four had more than two mounts or mounting attempts. None out of the Nellore bulls was collected with IAV. The IAV was an effective and welfare-promoting animal technology for the evaluation of semen quality and mating ability of B. taurus bulls. However, the IAV was not adequate for young Nellore bulls, probably due to their quiescent sexual behavior and delayed sexual maturity. Further studies are needed to evaluate the performance of the IAV for older Nellore bulls. © 2011 Elsevier B.V.


Felizardo V.,Centro Universitario Barriga Verde | Nandi V.S.,Centro Universitario Barriga Verde | Donadel K.,Centro Universitario Barriga Verde | Novais R.,University of Aveiro | And 2 more authors.
Revista Materia | Year: 2016

Conventional thermal insulation materials, such as glass wool and extruded polystyrene, owned-in significant technical limitations. The geopolymers emerge as an alternative due to their properties. In this sense the objective of this work is to describe the develop geopolymers with low thermal conductivity. Samples of geo-polymers were produced from metakaolin (Al2O3.2SiO2) which, due to its high reactivity, made it possible to produce inorganic polymers with interesting physical properties, which can be used for thermal insulation. The samples of aluminosilicate were activated with sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Samples of light geopolymers were produced with addition of different percentages of a pore former (0.5, 1, 2, 3, 4%). The samples were characterized with respect to: compressive strength, water absorption, thermal conductivity, density and microstructure. © 2016, Universidade Federal do Rio de Janeiro. All rights reserved.


Prestes N.E.,Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina | Do Amarante C.V.T.,Santa Catarina State University | Pinto C.E.,Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina | Prestes G.,Discente de Graduacao em Agronomia | And 3 more authors.
Semina:Ciencias Agrarias | Year: 2016

The objective of this study was to assess forage production in a natural grassland by applying different doses of limestone and phosphorus, and the influence of these applications on soil profile. The treatments consisted of the application of limestone doses of 0.0, 7.2, and 14.4 t ha-1 and phosphorus doses of 0, 35, 70, and 140 kg of P2O5 ha-1 on the soil surface. The experiment was conducted in a randomized complete block design with split-plots and three replications. The limestone doses were distributed in the main plot and applied only at the beginning of the experiment, whereas the phosphorus doses were distributed in the subplots with subsequent annual maintenance applications. Was used a ruler (cm) for monitoring the growth of pastures and, when grasses reached an average height of 20 cm, forage samples were collected in each subplot and botanical and morphological components were separated and dried until a constant weight was achieved. In the third and fourth assessment years, soil samples were collected in the 0-5, 5-10, 10-15, and 15-20-cm layers to evaluate the influence of treatments on the chemical properties of the soil. The variables analyzed were related to the production of several components, including fodder, native grasses, leguminous plants, unwanted plants, and dead material, in addition to soil properties such as pH, exchangeable aluminum concentration, and base saturation. There was no interaction between the limestone and phosphorus treatments. The effect of limestone doses on forage production was assessed in the third year, and, in the following year, the intermediate dose of limestone (7.2 t ha-1) produced the highest yield (2,316.1 kg of dry matter [DM] of forage ha-1). The increase in phosphorus doses increased forage production in the second year, and reached yields of up to 2,232 Kg DM ha-1 in the fourth year. In summary, the production of natural pastures was enhanced by the application of 25% of the recommended dose of limestone (7.2 t ha-1), and by the application of 50% of the recommended dose of phosphorus (70 kg P2O5 ha-1). The increase in limestone doses directly affected the chemical properties of the soil by decreasing acidity and exchangeable aluminum, and increasing base saturation, even in deeper layers (0-20 cm). The increase in phosphorus doses did not increase the mobility of this nutrient in the deeper layers of the soil (10-20 cm), and the effects were restricted to a depth of up to 10 cm.

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