Yazar "Erdogan, Ilhan" seçeneğine göre listele

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    Calculation of Intradonor Normalized Transition Energy in Spherical Quantum Dots Made of Different Materials
    (Wiley-V C H Verlag Gmbh, 2023) Mese, Ali Ihsan; Cicek, Engin; Ozkapi, Sena Guler; Ozkapi, Baris; Erdogan, Ilhan
    Under the effective mass approximation, the binding energies, transition energies between 1s and 1p states, and normalized transition energies of spherical quantum dots made of different materials are calculated using the variational method. In particular, binding, transition, and normalized transition energies are examined depending on the radius of the quantum dot and the position of the hydrogenic impurity. It is observed that the binding energy and transition energy decrease as the radius of the quantum dot increases, whereas the normalized transition energy increases. In all four different structures, it is seen that the binding energy first reaches a maximum and then starts to decrease according to the position of the hydrogenic impurity. In contrast, the transition energy behaves almost the opposite. Additionally, when the change of the normalized transition energy is examined according to the impurity position, it is determined that it decreases up to the value of r(i)/R = 0.6 and then remains almost constant. According to our literature review, the normalized transition energy for the four different quantum dots is calculated for the first time in this study.
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    CHEMICAL COMPOSITION OF WET, BULK, AND DRY DEPOSITION IN KIRKLARELI, TURKEY
    (Stef92 Technology Ltd, 2013) Oruc, Ilker; Akkoyunlu, Bulent O.; Erdogan, Ilhan
    This study presents that wet, bulk, and dry deposition types were investigated simultaneously in two areas in the Kirklareli city center and Kirklareli rural area in the period of June 2011 - September 2011. The rural area is located 3 km southwest of Kirklareli. During the study period, 8 wet, 8 bulk, and 12 dry samples were collected simultaneously in both sampling areas. The samples were analyzed for Na+, Mg2+, Ca2+, K+, NH4(+), Cl-, NO3- and SO42- in addition to pH and altogether 252 analysis were carried out. This paper presents a comparison between wet, bulk, and dry deposition concentrations of ions in the urban and the rural areas. Mg2+ was found to be the dominant cation for wet and bulk depositions in both sampling areas. The pH values of the wet deposition in the urban area varied from 6.04 to 6.75. The arithmetic mean concentrations of ions sampled in the rural area in the wet deposition were 17-75% higher than that of the urban area.
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    Effect of Si and Ge doping on electronic structure of InP nanowire
    (Natl Inst Optoelectronics, 2023) Ozkapi, Sena Guler; Ozkapi, Baris; Mese, Ali Ihsan; Erdogan, Ilhan
    We present a study on the effect of Si and Ge doping on the electronic and atomic structure of Indium Phosphide nanowires using first principles calculations. Hydrogen passivated InP nanowires in zinc blende structure with 1.5 nanometers diameter [111] growth direction are considered. The results show that the substitutional Si and Ge dopings narrow the band gap of InP nanowires, and these nanowires are direct band gap semiconductors. The Si doping shifts the VBM and CBM to the lower energy levels, and this energy decrease is less in the Ge doped nanowire. PDOS analyses show that VBM and CBM occur mainly from the p orbitals of the In and P atoms. Electronic states at the Fermi level for doped nanowires are compatible with the donor levels that appear in the band structure.
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    INVESTIGATION OF WET, BULK, AND DRY DEPOSITION CONCENTRATIONS IN KIRKLARELI, TURKEY
    (Stef92 Technology Ltd, 2013) Oruc, Ilker; Akkoyunlu, Bulent O.; Erdogan, Ilhan
    This study presents the chemical composition of wet, bulk, and dry deposition in the urban and in the rural area of Kirklareli city (Turkey) during the period of March 2011 June 2011. During the sampling period, 12 wet, 12 bulk, and 12 dry samples were collected simultaneously in the city center and in the rural area. Concentrations of main cations (Na+, Mg2+, Ca2+, K+, NH4+) and main anions (Cl-, NO3-, SO42-) were determined in wet, bulk, and dry samples; pH was also measured in these three deposition types. Predominant ions were identified. The mean wet deposition concentrations of all ions except K+ sampled in the city center were found to be higher than those of the rural area. The average pH values of the wet deposition in the urban and the rural area of Kirklareli city were found 6.53 and 6.45, respectively. The study showed that Ca2+ was the dominant cation and SO42- the dominant anion in all deposition samples in the city center. Ion sources in the wet, bulk, and dry depositions were found by calculating the enrichment factors (EFs).
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    Self-Polarization of Hydrogenic Impurity in Quantum Wells Made of Different Materials
    (Wiley-V C H Verlag Gmbh, 2022) Ozkapi, Baris; Mese, Ali Ihsan; Cicek, Engin; Erdogan, Ilhan
    The effect of the external electric field on the ground state binding energy and self-polarization of a hydrogenic donor impurity in quantum wells (QWs) made of different materials is calculated within the effective mass approximation using a variational scheme. The variations of binding energy and self-polarization depending on well width, electric field, and impurity position have been studied in detail. For each QW made of different materials, it has been observed that the binding energy decreases with the increase of the electric field, whereas the self-polarization increases. Also, it has been observed that InP/In1-x Ga x P has higher binding energy values among the structures discussed. It is seen that material selection has a noticeable effect on self-polarization and binding energy in QW-based structures.
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    The sources and seasonal variations of the chemical components in the deposition samples in Kirklareli, Turkey
    (Serbian Chemical Soc, 2022) Oruc, Ilker; Akkoyunlu, Bulent oktay; Erdogan, Ilhan
    This study was carried out in the central district of Kirklareli province in Turkey. It presents the chemical composition of three deposition types, namely wet, bulk and dry. In this study, 150 deposition samples (wet + bulk + dry) were collected for a year in the urban and suburban areas in the central district of Kirklareli. The concentrations of the main cations (Ca2+, K+, Na+, Mg2+, NH4+) and main anions (SO42-, Cl-, NO3-) in the collected deposition samples were determined. The seasonal variations of the concentrations of the major ions in the three deposition types were studied. The wet and dry deposition fluxes of major ions were calculated. Among the major ions, the ion with the highest annual mean flux values in the wet deposition is Ca2+ in the urban area, while it is Cl- in the suburban area. In the wet deposition, the annual mean flux values of Ca2+ in the urban area and Cl- in the suburban area were 65.40 and 38.09 mg m(-2) h(-1), respectively. The relationship between ion concentrations and acid deposition was also investigated and the sources of ions were determined. The arithmetic mean pH values of the samples in the urban and suburban areas were 6.39 and 6.14 in wet deposition, 6.75 and 6.41 in bulk deposition, and 7.36 and 6.56 in dry deposition, respectively. The backward trajectories arriving at the region during the study period were divided into two groups. In the first cyclone group, SO42- was to 97 % of anthropogenic origin in both the urban and suburban areas.