Tomak, Mehmet
In the phase-coherent transport regime the possibility of a solid-state electron biprism employing an intentionally implanted impurity in a split-gate heterostructure is theoretically studied. The impurity-assisted interference phenomenon has been investigated under several impurity profiles and positions within the constriction. The effect of gate width on quenching the interference has also been considered. A quantitative explanation is offered which is based on the Fourier analysis of the wave function at the aperture and the guided-mode dynamics within the constriction.


Quantum chemical treatment of cyanogen azide and its univalent and divalent ionic forms
Türker, Burhan Lemi; Atalar, Taner (Elsevier BV, 2008-05-30)
An explosive material, cyanogen azide (CN4) and its univalent and divalent anionic and cationic forms have been studied quantum chemically by using different theoretical approaches. In this study, the structures considered have been screened for their relative stabilities. Also, they have been investigated whether the charged forms play a role in the usual explosion process or any electrical charging during storage cause explosion. Various quantum chemical properties are obtained and discussed. It has been ...
Theoretical electronic spectra for models having ferredoxin-core
Türker, Burhan Lemi (2002-10-31)
Ferredoxin-core model [Fe4S4] type iron-sulfur cluster having four cysteine moieties in the amide form, has been considered theoretically for electronic excitation spectrum. The neutral as well as the -/+ 2 charged forms of the model have been investigated within the restrictions of ZINDO/S (RHF) approach involving configuration interaction considerations. The charged forms, especially the negative one exhibited some bathochromic shift and hyperchromic effect.
Hydrogen adsorption on Co2+ - and Ni2+- exchanged -US-Y and -ZSM-5. A combined sorption, DR UV–Vis, synchrotron XRD and DFT study
Sarohan, Nurkan; Özbek, Murat Oluş; Kaya, Yasemin; Abdellatief, Mahmoud; İpek Torun, Bahar (2022-08-01)
Hydrogen adsorption on Co2+and Ni2+exchanged Ultrastable-Y (US–Y) and ZSM-5 are investigated experimentally at 298K and up to 50bar as well as theoretically. The experimentally calculated initial isosteric heat of H2adsorption values are between −28 and −32kJ/mol for Ni2+-ZSM-5, -16kJ/mol for Co2+-ZSM-5, -23kJ/mol for Ni2+-US-Y and −18kJ/mol for Co2+-US-Y. Due to the optimumheat of adsorptionvalues observed on Co2+and Ni2+exchanged US-Y and ZSM-5, a reversiblevolumetricH2storage capacity of 20g H2/L is achi...
Accurate formation energies of charged defects in solids: A systematic approach
Vinichenko, Dmitry; Sensoy, Mehmet Gokhan; Friend, Cynthia M.; Kaxiras, Efthimios (2017-06-30)
Defects on surfaces of semiconductors have a strong effect on their reactivity and catalytic properties. The concentration of different charge states of defects is determined by their formation energies. First-principles calculations are an important tool for computing defect formation energies and for studying the microscopic environment of the defect. The main problem associated with the widely used supercell method in these calculations is the error in the electrostatic energy, which is especially pronou...
Modified acrylic hydrogels as controlled release systems
Pınardağ, Fatma Esra; Hasırcı, Nesrin; Department of Chemistry (2006)
In this study, pH-sensitive poly(acrylamide-co-acrylic acid) hydrogels were synthesized as controlled release systems in the presence of N,N-methylene bisacrylamide as crosslinker and ammonium persulfate as initiator. A set of hydrogels were used in the form they were prepared. One set of hydrogels were prepared as porous networks by incorporating sodium chloride into the reaction medium and then leaching of it after the completion of polymerization reaction. Two sets of hydrogels were modified by argon-pla...
Citation Formats
C. BULUTAY, N. GUNALP, and M. Tomak, “ELECTRON BIPRISM OPERATION OF SPLIT-GATE HETEROSTRUCTURES HAVING A SINGLE IMPURITY WITHIN THE CHANNEL,” JOURNAL OF APPLIED PHYSICS, pp. 5309–5317, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38614.