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Ljubljana, Slovenia

Horchidan N.,Al. I. Cuza University | Ianculescu A.C.,Polytechnic University of Bucharest | Vasilescu C.A.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Deluca M.,University of Leoben | And 7 more authors.
Journal of the European Ceramic Society | Year: 2014

A systematic study of BaSnxTi1-xO3 solid solutions (x=0-0.20) by a combined field-induced dielectric and ferroelectric analysis with Raman and PFM investigations was realized, in order to obtain new insights concerning the composition-induced modification of the structural phase transitions and ferroelectric-relaxor crossover induced by the increase of Sn addition. The ceramics prepared via solid state reaction and sintering at 1400°C/4h showed average tetragonal symmetry for x≤0.15 and cubic for x=0.20. However, the dielectric and Raman analysis demonstrated that x=0.05 and x=0.15 are characterized by a coexistence of phases, which enhances their macroscopic properties (polarization for x=0.05 and permittivity for x=0.15). The domain structure shows a gradual modification when increasing Sn addition. No detectable domain structure has been found for x≥0.15. All the compositions show local d33(V) hysteresis loops at room temperature. © 2014 Elsevier Ltd. Source

Trost A.,University of Ljubljana | Zemva A.,University of Ljubljana | Zemva A.,CO NAMASTE
MIPRO 2012 - 35th International Convention on Information and Communication Technology, Electronics and Microelectronics - Proceedings | Year: 2012

In the paper we present generic simulation test benches and test structures for the verification of the video processing circuits. The test benches accelerate simulation of the digital video frames in an ITU-R BT656 video format and a standard computer VGA format, which are most commonly used in our applications. The acceleration is achieved by selective stimuli in the area of the interest and selective collection of simulation results. We also present a custom FPGA based development system supporting both video formats. Several test structures were designed providing debug control and data for effective hardware verification. A video processing design case study is presented. With the presented verification methodology we are able to accelerate the design process of video processing circuits. The benefit of our approach is that it can be used with the standard programmable design tools and low cost platforms, since we do not require special software or hardware emulators. The approach can be used for the research or educational purpose. © 2012 MIPRO. Source

Krapez U.,University of Ljubljana | Slavec B.,University of Ljubljana | Steyer A.F.,University of Ljubljana | Pintaric S.,University of Ljubljana | And 5 more authors.
Avian Diseases | Year: 2012

Pigeon circovirus (PiCV) was detected by real-time PCR in cloacal swabs, pharyngeal swabs, and serum samples taken from 74 feral pigeons (Columba livia var. domestica) that were caught at various locations in the city of Ljubljana, Slovenia. PiCV infections were detected in the majority of the tested birds. The highest (74.3) detection rate was observed in the cloacal swabs and the lowest (31.1) in serum samples. PiCV DNA was more readily detected in the cloacal swabs, pharyngeal swabs, and serum samples of birds younger than 1 yr. Molecular analysis of partial open reading frame V1 sequences showed that PiCV strains detected in feral pigeons share high nucleotide and amino acid sequence identities with PiCV strains detected in ornamental, racing, meat, and feral pigeons. © American Association of Avian Pathologists. Source

Drmota A.,Nanotesla Institute Ljubljana | Drofenik M.,CO NAMASTE | Znidarsic A.,Nanotesla Institute Ljubljana | Znidarsic A.,CO NAMASTE
Ceramics International | Year: 2012

Nano-crystalline strontium hexaferrite (SrFe 12O 19) powder was synthesized using the classical co-precipitation and microemulsion methods. The precursors were obtained by precipitating Sr 2+ and Fe 2+ ions using tetramethylammonium hydroxide and calcinating at different temperatures ranging from 400 °C to 1000 °C in air. The influence of the Sr 2+/Fe 3+ mol ratio and the calcination temperature on the product formation and magnetic properties were studied. The formation of nanosized particles of SrFe 12O 19 with a relatively high saturation magnetization M s = 64 Am 2/kg, remanent magnetization of M r = 39 Am 2/kg and a coercitivity of H c = 5.5 kOe was achieved at a Sr 2+/ Fe 3+ mol ratio of 1:8 calcined at 900 °C. The formation of the SrFe 12O 19 was inspected using XRD analysis, thermogravimetric analysis (TGA), differential thermal analysis (DTA), TEM, and magnetic measurements. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Source

Drmota A.,Nanotesla Institute Ljubljana | Koselj J.,Nanotesla Institute Ljubljana | Drofenik M.,CO NAMASTE | Znidarsic A.,Nanotesla Institute Ljubljana | Znidarsic A.,CO NAMASTE
Journal of Magnetism and Magnetic Materials | Year: 2012

We have investigated composites designed for microwave absorption based on magnetic filler, composed of phases within the SrOFe 2O 3 system, embedded in a polyphenylene sulfide matrix with a concentration ratio of 80:20 by weight. The formation of the nanosized particles of SrFe 12O 19 and Fe 3O 4, as the principal magnetic phases was achieved via the co-precipitation of Sr 2/Fe 3 ions using different molar ratios. The various precursors obtained were calcined between 600 °C and 900 °C in air. The electromagnetic parameters of the composites were measured with a vector network analyzer at 400 MHz to 32 GHz. The results show that with a composite composed of a complex magnetic filler comprising the nanoparticles of two magnetically diverse phases, i.e., a spinel phase as the electromagnetic wave absorber in the lower GHz range and a hexagonal phase operating at a higher GHz range, above 32 GHz, a microwave absorber with an broad absorption range can be prepared. © 2011 Elsevier B.V. All rights reserved. Source

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