Browsing Fizik Bölümü / Department of Physics by Issue Date
Now showing items 1-20 of 168
-
The statistics of energy states of a Hookean model for proteins
(TÜBİTAK, 2000)A generic model of a random polypeptide chain, with discrete torsional degrees of freedom and Hookean springs connecting pairs of hydrophobia residues, reproduces the energy probability distribution of real proteins over ... -
Dissipative dynamics and the statistics of energy states of a Hookean model for protein folding
(Kluwer Academic Publishers-Plenum Publishers, 2000-07)A generic model of a random polypeptide chain, with discrete torsional degrees of freedom and Hookean spring connecting pails or hydrophobic residues, reproduces the energy probability distribution of real proteins over a ... -
Testing a hypothesis for the evolution of sex
(World Scientific Publishing Company, 2000-07-11)An asexual set of primitive bacteria is simulated with a lit-string Penna model with a Fermi function for survival. A recent hypothesis by Jan, Stauffer, and Moseley on the evolution of sex from asexual cells as a strategy ... -
Calculation of the T-X phase diagram for a mixture of liquid crystals
(Pergamon-Elsevier Science, 2000-12)In this study we calculate the T-X phase diagram for a mixture of liquid crystals. In this calculation we use a mean field theory We fit our calculated phase line equations to the experimental data from the literature. ... -
Evolutionary route to diploidy and sex
(National Academy of Sciences, 2001-11-20)By using a bit-string model of evolution, we find a successful route to diploidy and sex in simple organisms. Allowing the sexually reproducing diploid individuals to also perform mitosis, as they do in a haploid-diploid ... -
Strategies for the evolution of sex
(American Institute of Physics Inc., 2001-12)The maintenance of a macroscopic sexual population is addressed. As a scenario, the mechanism of random conversion to sex, in the presence of a constant rate of mutation is examined. This scenario is very closely related ... -
Effect of annealing temperature on determining trap depths of quartz by various heating rates method
(Pergamon-Elsevier Science, 2001-12)The aim of this study is to determine the trap parameters (trap depth E, frequency factors) of quartz using various heating rates method and also to investigate the effect of annealing temperature on determining trap depths. ... -
Strategies for the evolution of sex
(American Physical Soc, One Physics Ellipse, 2001-12)We find that the hypothesis made by Jan, Stauffer, and Moseley [Theory Biosci. 119, 166 (2000)] for the evolution of sex, namely, a strategy devised to escape extinction due to too many deleterious mutations, is sufficient ... -
T-P phase diagram of ammonia solid phases I, II and III
(Elsevier Science, 2002-01-02)In this study, using the mean field theory, we obtain temperature versus pressure phase diagram for the liquid and solid phases I, II, and III of ammonia. We fit, our phase line equations to the experimentally observed ... -
P-T phase diagram for NH₄F
(Editions Scientifiques Medicales Elsevier, 2002-04)In this study we obtain a P-T phase diagram of NH4F using the mean-field theory. We fit our calculated phase line equations to the experimental P-T phase diagram. By choosing appropriately the coefficients in the free-energy ... -
A phase diagram near the NAC point in liquid crystals
(Elsevier Science SA, 2002-07-28)In this study using a mean field model we obtain the phase line equations for the NA. NC and AC transitions near the NAC point in a mixture of liquid crystals. We then fit these phase line equations to the experimental ... -
Monitoring diffusion of reptating polymer chains by a direct energy transfer method: A Monte Carlo simulation
(Wiley-Blackwell, 2002-07-29)A kinetic Monte Carlo method was used to simulate the diffusion of reptating polymer chains across an interface. A time-resolved fluorescence technique in conjunction with a direct energy transfer method was used to measure ... -
A mean field model near the NAC point in liquid crystals
(Physical Soc Republic China, 2002-10)In this study we obtain the phase line equations for the nematic-smectic A (NA), smectic A-smectic C (AC) and nematic-smectic C (NC) transitions using a mean field model. We fit these phase line equations to the experimental ... -
Normal forms and nonlocal chaotic behavior in Sprott systems
(Pergamon-Elsevier Science, 2003-06)The Sprott systems are used as benchmarks for investigating the applicability of the normal form transformation in estimating nonlocal properties of attractors such as positive and zero Liapunov exponents. Possibility of ... -
Signals of chaotic behavior in PMMA
(Pergamon-Elsevier Science, 2003-07)The time evolution of the current passing through PMMA polymer thin films under 10 V at 23degreesC (296 K) was sampled at intervals ranging from 1 to 20 s. The data showed chaotic behavior in the context of pinned charge ... -
Breakdown of the Stokes-Einstein relation in supercooled liquids
(Trans Tech Publications Ltd, 2004)Breakdown of the Einstein-Stokes relation in undercooled liquids is one of the unsolved problems in the theory of liquids. The self-diffusion coefficient follows the temperature dependence of the Einstein-Stokes equation ... -
Theoretical calculation of the kinetic coefficient of normal crystal growth
(Trans Tech Publications Ltd, 2004)An expression for the velocity u of migration of a diffuse simple crystal-melt interface has been derived on the basis of the theory of atomic mobility in supercooled liquids: u = K-0 (T / T-m) DeltaT, where DeltaT = T-m ... -
Fluctuation theory of the liquid-glass transition
(Trans Tech Publications Ltd, 2004)The glassy state and the character of the liquid-glass transition from undercooled liquid to amorphous solid is one of the biggest challenges of our time. In spite of significant progress we still cannot explain accurately ... -
A model of AlN layer formation during ion nitriding of Al
(Springer-Verlag, 2004-11)A diffusion model of AlN layer formation by ion nitriding of Al is proposed based on the analysis of atomic transport during the process. This model is reduced to the following. Implantation of N ions to the surface of the ... -
Determination of pre-gelation and post-gelation activation energies during free radical crosslinking copolymerization
(Taylor & Francis Ltd, 2005)Steady-state fluorescence (SSF) and dilatoraetric techniques were used to study the free-radical crosslinking copolymerization (FCC) of styrene (S) and divinylbenzene (DVB) in bulk. The gel points (t g) were recorded by ...
