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Article Citation - WoS: 4Citation - Scopus: 5Roof Shape Modelling for Multiple Diffraction Loss in Cellular Mobile Communication Systems(Taylor & Francis Ltd, 2002) Kara, A; Yazgan, EThe effects of roof shapes on multiple diffraction loss in cellular mobile communication systems are investigated. Building roofs are modelled as finitely conducting wedges with different, included angles (peaked roofs). Multiple diffraction loss, a measure of diffraction loss due to multiple building geometry, is computed by using the method of UTD (uniform theory of diffraction) for 90degrees and 120degrees wedges over the communication paths oblique to building blocks. The results, compared with the absorbing edge model, 0degrees wedge, show that multiple diffraction loss decreases with increasing wedge angle.Article Citation - WoS: 1Citation - Scopus: 2Study of trapping and recombination centres in Tl2InGaTe4 chain crystals by dark electrical conductivity and photoconductivity measurements(Taylor & Francis Ltd, 2007) Qasrawi, A. F.; Gasanly, N. M.Dark electrical conductivity and photoconductivity of Tl2InGaTe4 single crystals have been measured and analyzed in the temperature region 100-300 K. The dark electrical conductivity measurements revealed an intrinsic- or extrinsic-type of conductivity above or below 210 K, respectively. From intrinsic conductivity data analysis, the energy band gap of Tl2InGaTe4 crystals was determined as 0.85 eV. In the extrinsic region, the dark conductivity arises from a donor energy level located at 0.30 eV below the conduction band. The photocurrent increases with increasing illumination intensity. The recombination mechanism in the crystal changes as temperature decreases due to the effect of exponential trapping centres. Two trapping and/or recombination centres located at 89 and 27 meV were determined from the temperature dependence of the photocurrent, which decreased or increased with increasing temperature in the regions above or below 180 K, respectively.Editorial Special Issue: in Honour of Professor A. Okay Celebi on the Occasion of His 70th Birthday Preface(Taylor & Francis Ltd, 2013) Aksoy, Umit[No Abstract Available]
