YALÇIN Kalkan | Abant Izzet Baysal University, Bolu, Turkey (original) (raw)

Papers by YALÇIN Kalkan

Social Science Research Network, 2022

Organic Electronics, Dec 1, 2022

EPJ Web of Conferences, 2018

In this work, a reaction mechanism of formation of noble gas (Ng) cluster ions has been theoretic... more In this work, a reaction mechanism of formation of noble gas (Ng) cluster ions has been theoretically investigated in detail. The kinetic studies of formation of Xe + Xe cluster in Xe, Ar + Ar cluster ions in Ar, and Ne + Ne cluster ions in Ne have been made as theoretically. The optimized structures in the ground state were calculated using the density functional theory (DFT) by the B3LYP method combined with the Stuttgart/Dresden effective core potential basis set (SDD). In addition, we calculated the rate constants of all cluster formations. The results are 1.15 × 10 −31 , 3.58 × 10 −31 , 0.23 × 10 −31 cm 6 /s, respectively for Neon, Argon, Xenon cluster ions.

Journal of Instrumentation

Avalanches in gas-based detectors operating at atmospheric pressure and using Ar-CO2 or Ne-CO2 as... more Avalanches in gas-based detectors operating at atmospheric pressure and using Ar-CO2 or Ne-CO2 as drift medium produce in a first instance mainly Ar+, Ne+ and CO2+ ions. The noble gas ions transfer their charge to CO2 in a few ns. A few ns later, the CO2+ ions have picked up CO2 molecules, forming cluster ions, in particular CO2+.(CO2)n. Since the cluster ions are slower than the initial ions, the signals induced by ion motion are altered. The effect is shown to be present in constant-field detectors and TPC readout chambers, and is expected to affect devices such as Micromegas and drift tubes.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2015

Abstract Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecul... more Abstract Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecules create large protonated water clusters around a H + core. In this context, the reactions H 3 O + ( H 2 O ) n − 1 + H 2 O → H 3 O + ( H 2 O ) n ( n =1–9) were studied in the gas phase. Structures for these clusters are suggested and the most stable structures for each cluster size are shown. The thermodynamic parameters Δ H n − 1 , n 0 , Δ G n − 1 , n 0 , Δ S n − 1 , n 0 and equilibrium constants K n − 1 , n for the reaction were calculated to determine the size of the water clusters. The results are close to experimental data found in the literature. Protonated water clusters at stp have a size of 6–9 which corresponds to a mass of 127.1 – 181.2 g / mole .

EPJ Web of Conferences, 2018

We have studied how water modifies the surface of graphene and in particular how the surface cond... more We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT) with the B3LYP hybrid functional combined with the 6-31G(d) basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

Social Science Research Network, 2022

Organic Electronics, Dec 1, 2022

EPJ Web of Conferences, 2018

In this work, a reaction mechanism of formation of noble gas (Ng) cluster ions has been theoretic... more In this work, a reaction mechanism of formation of noble gas (Ng) cluster ions has been theoretically investigated in detail. The kinetic studies of formation of Xe + Xe cluster in Xe, Ar + Ar cluster ions in Ar, and Ne + Ne cluster ions in Ne have been made as theoretically. The optimized structures in the ground state were calculated using the density functional theory (DFT) by the B3LYP method combined with the Stuttgart/Dresden effective core potential basis set (SDD). In addition, we calculated the rate constants of all cluster formations. The results are 1.15 × 10 −31 , 3.58 × 10 −31 , 0.23 × 10 −31 cm 6 /s, respectively for Neon, Argon, Xenon cluster ions.

Journal of Instrumentation

Avalanches in gas-based detectors operating at atmospheric pressure and using Ar-CO2 or Ne-CO2 as... more Avalanches in gas-based detectors operating at atmospheric pressure and using Ar-CO2 or Ne-CO2 as drift medium produce in a first instance mainly Ar+, Ne+ and CO2+ ions. The noble gas ions transfer their charge to CO2 in a few ns. A few ns later, the CO2+ ions have picked up CO2 molecules, forming cluster ions, in particular CO2+.(CO2)n. Since the cluster ions are slower than the initial ions, the signals induced by ion motion are altered. The effect is shown to be present in constant-field detectors and TPC readout chambers, and is expected to affect devices such as Micromegas and drift tubes.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2015

Abstract Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecul... more Abstract Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecules create large protonated water clusters around a H + core. In this context, the reactions H 3 O + ( H 2 O ) n − 1 + H 2 O → H 3 O + ( H 2 O ) n ( n =1–9) were studied in the gas phase. Structures for these clusters are suggested and the most stable structures for each cluster size are shown. The thermodynamic parameters Δ H n − 1 , n 0 , Δ G n − 1 , n 0 , Δ S n − 1 , n 0 and equilibrium constants K n − 1 , n for the reaction were calculated to determine the size of the water clusters. The results are close to experimental data found in the literature. Protonated water clusters at stp have a size of 6–9 which corresponds to a mass of 127.1 – 181.2 g / mole .

EPJ Web of Conferences, 2018

We have studied how water modifies the surface of graphene and in particular how the surface cond... more We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT) with the B3LYP hybrid functional combined with the 6-31G(d) basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.