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Aradoaei S.,Technical University Gheorghe Asachi | Ciobanu R.C.,Technical University Gheorghe Asachi | Darie R.,Petru Poni Institute of Macromolecular Chemistry | Zaharescu T.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Caramitu A.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca
Materiale Plastice | Year: 2013

Nowadays, the growing environmental awareness throughout the world has triggered a paradigm shift towards designing environmentally friendly materials. The interest in cellulose fibers as reinforcement agents in composite materials with polymer matrices has increased dramatically in the last decades, the main reasons associated with this upsurge being their renewable and ubiquitous character, good mechanical properties, low density, low cost and recyclability. Focus on dielectric spectroscopy technique, the article makes a comparison between the dielectric properties of transformer board and composite materials obtained by mixing recycled polyethylene with wood powder or lignin in different percentages. Source


Ungureanu D.N.,Universitatea valahia din targoviste | Angelescu N.,Universitatea valahia din targoviste | Tsakiris V.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Marinescu V.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca
Revista Romana de Materiale/ Romanian Journal of Materials | Year: 2012

In this paper is presented a synthesis method of calcium phosphate bioceramics such as hydroxiapatite, the mineral component of bones and hard tissue in mammals. Hydroxyapatite powders have been obtained by chemical coprecipitation, by using calcium hydroxide and ortophosphoric acid as a source of calcium and phosphorus. The synthesized powders were characterized by X - ray diffraction, dynamic light scattering technique (DLS) and scanning electron microscopy (SEM). The proposed method lead to obtain a hydroxyapatite with a degree of crystallinity, greater than 80%, in case of all samples thermal treated at 800°C. Source


Marin D.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Mitulet A.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Lingvay M.,Babes - Bolyai University
EEA - Electrotehnica, Electronica, Automatica | Year: 2013

There were determined the active, the reactive and apparent power for different types of lightning lamps as well as their illuminance level. Following the processing and analysis of the experimental results, there was showed that the ratio of illuminance level / power is maximum in the case of LED lamps, with the disadvantage of a low power factor (λ ≈ 0.5). Source


Melinescu A.,Polytechnic University of Bucharest | Velciu G.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Marinescu V.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Preda M.,Polytechnic University of Bucharest
Revista Romana de Materiale/ Romanian Journal of Materials | Year: 2011

The IT-SOFC cells are consisting of three main components: solid electrolyte, cathode and anode. A solid electrolyte was synthesized based on solid solutions of CeO2 with strontium oxide, which was sintered at 1400°C. The solid electrolyte obtained has the relative density of 71% of theoretical density. The composition, La0,45Sr0,55MnO3 was used to obtain a cathode. The anode was prepared using a CeO2-CuO cermets. The heat treatment was performed at 1050°C for the cathode and at 970°C for the anode. By X-ray diffraction, was determined that the solid electrolyte consists of a solid solution with specific structure of cerium oxide and small amounts of SrCeO3 and the cathode is a solid solution of type La1-xSrxMnO3. The two electrodes were deposited by spraying on the solid electrolyte and the thickness of layers was 65-85 μm. By scanning electron microscopy there was found a good adhesion of the electrodes at solid electrolyte. No cracks were observed that may indicate mechanical incompatibility between the solid electrolyte and electrodes. Source


Velciu G.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Velciu G.,Polytechnic University of Bucharest | Seitan C.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | Dumitru A.,Institutul National Of Cercetare Dezvoltare Pentru Inginerie Electrica Icpe Ca | And 4 more authors.
Revista Romana de Materiale/ Romanian Journal of Materials | Year: 2013

Solid electrolyte fuel cells (SOFC), the cleanest sources of electricity generation, are formed of three main components: solid electrolyte, cathode and anode. The cathode and anode (electrodes) are activation support of electrochemical reactions and transporting charge carriers, electrons and partly or totally ions. With electrolyte forms a triple interface gas - electronic solid - solid ionic that changes abruptly the conduction mechanism from electronic (TPB - Triple Phase Boundary) to ionic. The study of processes taking place in the TPB in a solid electrolyte fuel cell is important for optimization of electrochemical reactions. This paper presents the structural and microstructural characteristics of interfaces cathode / electrolyte / anode in a fuel cell with solid electrolyte with following ceramic components: solid electrolyte on CeO2 based with addition of calcium oxide and yttrium oxide, cathode of perovskite type based on lanthanum manganite doped (LSM) with strontium and anode a cermet from cerium oxide doped with gadolinium (Ni-CeGd). Mineralogical composition of components used for the fuel cell was performed by X-ray diffraction. Its microstructure was determined by electron microscopy, and the distribution of chemical elements at interfaces cathode / electrolyte and anode / electrolyte was examined by EDX. Cathode and anode surface condition was examined by AFM. The results show a good adhesion of the layers used as electrodes on solid electrolyte support. Source

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