Sen, F. G.
Kinaci, A.
Aydınol, Mehmet Kadri
FeTi can store 3.7 wt% hydrogen if it is synthesized in the form of FeTiH4. In the present study, candidate alloying elements were investigated that would decrease the formation energy of this hydride, using first principles calculations within the generalized gradient approximation (GGA) to density functional theory (DFT). Selected alloying elements are Co, Mg, Mo, Ni, Nb, V and Zr, and they were substituted for Fe or Ti atoms separately. Their effects on the formation energy of FeTiH4 were analyzed on the basis of electronic structure. It was found that Zr, Nb, Mo and Mg substitution for Fe decreases the formation energy of the hydride considerably. Stabilization is achieved by forming stronger bonds between hydrogen atoms and rest of the Fe atoms in the structure which is facilitated by the antibonding between the hydrogen atoms and the substituted high tendency hydride forming element.


Effect of Nb addition on the critical parameters of BSCCO superconductor
Sozeri, H.; Ghazanfari, N.; Oezkan, H.; Kılıç, Adnan; Hasanlı, Nızamı (2007-04-12)
Pure and Nb2O5 added Bi1.6Pb0.4NbxSr2Ca2Cu3O delta superconductors (0 <= x <= 0.30) were synthesized by the ammonium nitrate melt route. Fraction of the high T-c 2223 phase increases with addition of small amounts of Nb. AC susceptibility and transport measurements showed the optimum Nb concentration as x = 0.10. Nb additions above x = 0.20 decrease significantly the fraction of the high-T-c phase and degrade the superconducting properties.
KOCAK, HI; ARAS, L (Elsevier BV, 1990-07-01)
The solution behaviour of Na, Ba, Zn and Al ionomers of methyl methacrylate-methacrylic acid copolymer (P(MMA-MAA)) with different ion contents has been studied by viscosity and dipole moment measurements. Two solvents with different character are chosen for viscosity measurements: dioxane (ε = 2.22) and acetone (ε = 20.7). The expected polyelectrolyte behaviour of the ionomers in acetone is reflected by the viscometric measurements. Mean squared dipole moment 〈μ2〉 values are calculated over a temperature r...
Effect of hydrogen ion-exchange capacity on activity of resin catalysts in tert-amyl-ethyl-ether synthesis
Boz, N; Doğu, Timur; Murtezaoglu, K; Dogu, G (Elsevier BV, 2004-08-10)
Activities of ion-exchange resin catalysts, having different hydrogen exchange capacities ranging between 5.1 and 1.3 meq H+/g, on the etherification reactions of 2M1B (2-methyl-1-butene) and 2M2B (2-methyl-2-butene) with ethanol were experimentally tested in a fixed bed reactor. These catalysts were prepared by the heat treatment of Amberlyst-15 catalysts at 220 degreesC at different durations of time and also by the synthesis of sulfonated styrene divinyl benzene cross-linked resins. Activity of these cat...
Effect of Midsynthesis Addition of Silica to the Synthesis Medium on the Properties of MFI-Type Zeolite Membranes
Soydas, Belma; Kalıpçılar, Halil; Culfaz, Ali (American Chemical Society (ACS), 2010-06-02)
Thin zeolite membranes of MFI type were prepared on alpha-Al2O3 supports by midsynthesis addition of silica in a recirculating flow system at 95 degrees C The synthesis was started with the batch composition of 80SiO(2): 30TPAOH:1500H(2)O which was changed to 80SiO(2)center dot 9TPAOH:1500H(2)O by addition of silica Mkt 24, 48, or 72 h Compared to synthesis at constant composition. it is possible to affect the rates of nucleation and crystal growth to obtain membranes with better quality by changing the ove...
Effect of pectin methyl esterase (PME) and CaCl2 infusion on the cell integrity of fresh-cut and frozen-thawed mangoes: An NMR relaxometry study
Kırtıl, Emrah; Öztop, Halil Mecit; Barrett, Diane M.; McCarthy, Michael J. (Elsevier BV, 2014-12)
This study describes the use of Nuclear Magnetic Resonance (NMR) relaxometry to understand the effect of pectin methyl esterase (PME) + CaCl2 infusion under different conditions on cell integrity of fresh-cut and frozen-thawed mangoes. Infusion experiments were performed at: atmospheric pressure, vacuum conditions of 50 kPa and 10 kPa. For NMR relaxometry experiments T-2 (spin-spin relaxation time), T-1 (spin-lattice-relaxation times) and 2D T-1-T-2 experiments were performed. Results showed that, as the se...
Citation Formats
F. G. Sen, A. Kinaci, and M. K. Aydınol, “EFFECT OF ALLOYING ELEMENTS ON THE FORMATION OF FeTiH4: AN AB INITIO STUDY,” 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54525.