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Takacova A.,1VURUP | Smolinska M.,Comenius University | Ryba J.,Institute of Chemical Technology | Mackulak T.,Institute of Chemical Technology | And 3 more authors.
Central European Journal of Chemistry | Year: 2014

In this work for disposal of the biologically hard decomposed pollutant Benzo[a]Pyrene (BaP) photooxidation Chlorella kessleri was used. The simulation model system under the different experimental conditions (varying biomass and light intensity) was evaluated. For quantitative analysis of the decrease in BaP, GC/MS technique was used. The highest degradation efficiency was achieved in the case of biomass from the culture of live algae (29%) and light intensity at level of 13.5 W m-2. When the dry biomass was used, degradation under the same conditions was lower because of lack of enzymatic activity in the system. © Versita Sp. z o.o. Source


Buc D.,Institute of Electronics and Photonics
Journal of Physics and Chemistry of Solids | Year: 2014

Polyethylene-terephthalate (PET) foils and glass slides coated with thin conductive layers were used as substrates for TiO2 or ZnO based photoactive electrodes of dye-sensitized solar cells (DSSC) with organo-metallic Ru-dye, standard iodine electrolyte and Pt coated FTO/glass counterelectrode (CE). Different compositions of nanoparticle oxides in forms of alcohol pastes as well as the CE paste were applied onto the substrates by screen printing or by doctor blade techniques. Photocurrents and I-V loading characteristics were measured depending on the solar cell structure and preparation, including the oxide composition, electrode conductivity and the dye type. The influence of thin TiO2 blocking layer prepared by sol-gel technique is also discussed. © 2014 Elsevier Ltd. Source


Hribik J.,Institute of Electronics and Photonics | Bobek P.,Institute of Electronics and Photonics | Fuchs P.,Institute of Electronics and Photonics
Proceedings of 23rd International Conference, RADIOELEKTRONIKA 2013 | Year: 2013

Repetition rate method of the air flow velocity measurement (the air flows inside a rectangular tube) is investigated. Two oscillators, each of which consists of a driver stage, ultrasound transmitter and receiver and an amplifier, use a feedback downstream and upstream the air flow, respectively. A difference frequency is subsequently derived. The advantage of this method is the cancelation of the influences of such factors as temperature, humidity, pollution, etc. of the flowing air on the difference frequency. The attempt to describe the influence of nonsymmetry concerning the propagation path lengths and sensitivity analysis is made and the derived equations are given. © 2013 IEEE. Source


Liday J.,Institute of Electronics and Photonics | Vogrincic P.,Institute of Electronics and Photonics | Hotovy I.,Institute of Electronics and Photonics | Sitter H.,Johannes Kepler University | Bonanni A.,Johannes Kepler University
Journal of Electrical Engineering | Year: 2011

We have studied the electrical properties and depth concentration profiles of Au/Ni-Zn-O/p-GaN and Au/Ni-Zn/p-GaN, thus of structures containing zinc as a p-type dopant utilized to increase the concentration of free charge carriers in the subsurface region of GaN and to gain a low-resistance ohmic contact. The layers were deposited on p-GaN by DC reactive magnetron sputtering. The prepared contact structures were annealed in N 2, structure Au/Ni-Zn/p-GaN also in O 2. The contact structures containing zinc exhibited lower values of contact resistivity in comparison with those without zinc. It was also found that the values of contact resistivity for both Au/Ni-Zn-O/p-GaN and Au/Ni-Zn/p-GaN were the same, thus it was not affected by the presence of a small content of oxygen (<0.2 at%) in the working atmosphere during the deposition of layers. Similarly, various gaseous ambients (N 2 or a mixture of N 2+O 2) during subsequent annealing of the contacts had no observable influence upon the magnitude of the contact resistivity. In our opinion the ohmic nature of the Au/Ni-Zn-O/p-GaN and Au/Ni-Zn/p-GaN contacts is related to a reconstruction of the contacts to a sequence metal/p-NiO/p-GaN due to annealing in nitrogen or in a mixture of oxygen and nitrogen and the ohmic properties of the contacts are predetermined by creating a thin NiO oxide layer on the metal/p-GaN interface. We believe that the lower values of the contact resistance in Au/Ni-Zn-O/p-GaN and Au/Ni-Zn/p-GaN contacts than in structure Au/Ni-O/p-GaN are caused by an enhanced hole concentration in the surface region of p-GaN due to zinc diffusion from the zinc-doped contact layer. © 2011 FEI STU. Source


Tomas K.,Slovak University of Technology in Bratislava | Tomas K.,Institute of Electronics and Photonics
Journal of Electrical Engineering | Year: 2015

In this paper the intelligibility of ideal binary-masked noisy signal is evaluated for different signal to noise ratio (SNR), mask error, masker types, distance between source and receiver, reverberation time and local criteria for forming the binary mask. The ideal binary mask is computed from time-frequency decompositions of target and masker signals by thresholding the local SNR within time-frequency units. The intelligibility of separated signal is measured using different objective measures computed in frequency and perceptual domain. The present study replicates and extends the findings which were already presented but mainly shows impact of room acoustic on the intelligibility performance of IBM technique. © 2015 Faculty of Electrical Engineering and Information Technology, Slovak University of Technology Source

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