Metav R and D

Bucharest, Romania

Metav R and D

Bucharest, Romania
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Ragnarsdottir K.R.,Innovation Center Iceland and Gerosion | Karlsdottir S.N.,University of Iceland | Leosson K.,Innovation Center Iceland | Arnbjornsson A.,Innovation Center Iceland | And 5 more authors.
NACE - International Corrosion Conference Series | Year: 2017

Development is needed for new materials and technology to extend the life and reliability of material surfaces used in geothermal steam turbines. A test unit was designed so that steam flows directly from the wellhead into the test unit through a nozzle where the steam is flashed at high velocity on the target area. This setup simulates the effect of erosion and erosion-corrosion in geothermal steam turbines in Iceland. Well HE-29 at Hellisheidi geothermal power plant was selected for testing. The steam from the wellhead had temperatures around 210°C at 18 bar pressure and it contained dissolved gases, including H2S and CO2. In the preliminary experiment 12 low carbon steel plates were coated with different spraying methods and materials to obtain protective layers with improved erosion-corrosion resistance for geothermal turbine environment. The experiments will explore which of the tested spraying methods and materials are the most suitable for this application. This paper reports the first results from the tests and inspection of the coatings on the low carbon steel including; visual inspection, microstructural and chemical composition analysis with SEM and XEDS. © 2017 by NACE International.

Baicea C.M.,Polytechnic University of Bucharest | Luntraru V.I.,Polytechnic University of Bucharest | Vaireanu D.I.,Polytechnic University of Bucharest | Vasile E.,Metav R and D | Trusca R.,Metav R and D
Central European Journal of Chemistry | Year: 2013

In this paper we present the synthesis of two composite membranes with sulfonated polyether etherketone as support polymer and as conductive polymers: polyaniline and poly(p-phenylenediamine) - which has a similar structure with polyaniline. The support membranes were obtained by the phase inversion process, the conductive polymers were added by in situ polymerization into the membrane pores, and to increase the conductive properties they were doped with polystyrene sulfonic acid. The synthesized membranes were characterized by FT-IR spectroscopy, SEM, EDAX and electrochemical impedance spectroscopy. © 2012 Versita Warsaw and Springer-Verlag Wien.

Baicea C.,Polytechnic University of Bucharest | Nechifor A.C.,Polytechnic University of Bucharest | Vaireanu D.I.,Polytechnic University of Bucharest | Gales O.,Polytechnic University of Bucharest | And 2 more authors.
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2011

Sulfonated poly (ether ether ketone) membranes were obtained by the phase inversion process. These membranes were modified with chemically in situ polymerized polypyrrole in order to increase the ionic conductivity and to prevent the methanol crossover. For improving the polypyrrole ionic conductivity, this was activated with iron chloride and cerium sulfate. The new synthesized sPEEK/Ppy composite membranes were characterized by FT-IR spectroscopy, Scanning Electron Microscopy, Energy dispersive X-ray spectroscopy (EDAX), permeation measurements and the ionic conductive properties were evaluated by Electrochemical Impedance Spectroscopy.

Pavel E.,Storex Technologies | Jinga S.I.,Polytechnic University of Bucharest | Vasile B.S.,Polytechnic University of Bucharest | Dinescu A.,Romanian National Institute for Research and Development in Microtechnologies | And 3 more authors.
Optics and Laser Technology | Year: 2014

Many attempts have been made to break the diffraction limit, a major problem in optical lithography. Here, we report and demonstrate a lithography method, quantum optical lithography, able to attain 1 nm resolution by optical means using new materials (fluorescent photosensitive glass-ceramics and QMC-5 resist). The performance is several times better than that described for any optical or electron beam lithography (EBL) methods. The written patterns on resist were transferred to Si wafer. SEM measurements show 5 nm line widths. © 2014 Elsevier Ltd.

Morjan I.P.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Alexandrescu R.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Morjan I.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Luculescu C.,Romanian National Institute for Lasers, Plasma and Radiation Physics | And 4 more authors.
Journal of Nanoparticle Research | Year: 2013

Nitrogen-containing carbon nanotubes (CNx-NTs), with a relatively high level of nitrogen doping were prepared by the catalytic laser-induced CVD method. The nanotubes were catalytically grown directly on a silicon substrate from C2H2/NH3 gaseous precursors. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) give firm evidence for the nitrogen doping. As determined by XPS, the N concentration for the prepared CNx-NTs increases from 3.6 to 30.6 at.% with increasing ammonia concentration and pressure. TEM images indicate that the nanotubes are bamboo like. As the nitrogen content increases, there is a transition from the bamboo shape with few defects and little distortion to a corrugated structure with a much larger number of defects. Raman spectroscopy revealed that with increasing nitrogen concentration, there is more disorder and defects, together with an increase in ID/IG ratio. By energy-filtering TEM, a higher N concentration was found on the outer amorphous nanolayer than in the compartment core of the nanotubes. © Springer Science+Business Media 2013.

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