Scopus İndeksli Yayınlar / Scopus Indexed Publications
Permanent URI for this collectionhttps://hdl.handle.net/11413/6358
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Browsing Scopus İndeksli Yayınlar / Scopus Indexed Publications by Publisher "Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA"
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Publication A Natural Limit on the Observable Periods of Anomalous X-ray Pulsars and Soft Gamma-ray Repeaters(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2011) Ertan, Ünal; Çalışkan, Şirin; Ekşi, Kazım Yavuz; Erkut, M. Hakan; Alpar, M. Ali; 179806; 273308; 26028We investigate the dependence of the evolution of neutron stars with fallback disks on the strength of the magnetic dipole field of the star. Using the same model as employed by Ertan et al. (2009), we obtain model curves for different dipole fields showing that the neutron stars with magnetic dipole fields greater than similar to 10(13) G on the surface of the star are not likely to become anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs). Other sources with conventional dipole fields evolve into the AXP phase if their disk can penetrate the light cylinder. The upper limits to the observed periods of AXP and SGRs could be understood if the disk becomes inactive below a low temperature around 100 K. We summarize our present and earlier results indicated by the evolutionary model curves of these sources with an emphasis on the importance of the minimum disk temperature and the X-ray irradiation in the long-term evolution of AXPs and SGRs with fallback disks.Publication Finite Difference Method for Stochastic Parabolic Equations(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2011) Şan, Mehmet Emin; Ashyralyev, AllaberenIn the present paper the single step difference schemes for the multi-point non local-boundary value problems for the stochastic parabolic equation are presented. The convergence estimates for the solution of these difference schemes are established. In applications this abstract result permit us to obtain the convergence estimates for the solution of difference schemes for the numerical solution of multi-point non-local boundary value problems for parabolic equations. The theoretical statements for the solution of this difference schemes are supported by the results of numerical experiments.Publication High-Frequency QPOs as a Product of Inner Disk Dynamics around Neutron Stars(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2011) Erkut, M. HakanThe kHz QPOs observed in a neutron star low mass X-ray binary are likely to be produced in the innermost regions of accretion disk around the neutron star. The rotational dynamics of the inner disk can be characterized by the presence of either sub-Keplerian or super-Keplerian accretion flow depending on the relative fastness of the neutron spin as compared to the Keplerian frequency at the inner disk radius. Within the magnetosphere-disk interaction model, the frequency difference between the two kHz QPOs observed in a given source can be estimated to be slightly higher than or nearly around the neutron star spin frequency if the neutron star is a slow rotator and less than the stellar spin frequency if the neutron star is a fast rotator.Publication Matrix Isolation Infrared Spectra and Photochemistry of Hydantoin(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2013-01-31) Nunes, Claudio M.; Fausto, Rui; ILDIZ, GÜLCE ÖĞRÜÇ; 107326Hydantoin (C3H4N2O2, 2,4-imidazolidinedione) was isolated in argon matrix at 10 K and its infrared spectrum and unimolecular photochemistry were investigated. The molecular structure of the compound was studied both at the DFT(B3LYP) and MP2 levels of approximation with valence triple- and quadruple-zeta basis sets (6-311++G(d,p); cc-pVQZ). It was concluded that the minima in the potential energy surfaces of the molecule correspond to C-1 symmetry structures. However, the energy barrier separating the two-equivalent-by-symmetry minima stays below their zero-point energy, which makes the C-s symmetry structure, which separates the two minima, the experimentally relevant one. The electronic structure of the molecule was studied in detail by performing the Natural Bond Orbital analysis of its electronic configuration within the DFT(B3LYP)/cc-pVQZ space. The infrared spectrum of the matrix isolated compound was fully assigned also with help of the theoretically predicted spectrum. Upon irradiation at lambda = 230 nm, matrix-isolated hydantoin was found to photofragment into isocyanic acid, CO, and methylenimine.Publication Position Observations of NEAs at the RTT150(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2008) Aslan, Zeki; Ivantsov, Anatoliy V.; Gumerov, Rustem I.; Hudkova, Lyudmila A.; Khamitov, Irek; Pinigin, Gennadiy I.; 142225In 2004-2007, 560 observations of 17 Near-Earth Asteroids of 15-21 magnitudes were made at the Russian-Turkish telescope (RTT150). The reduction was made using reference stars from the UCAC2 and USNO-B1 catalogues. The comparison of the observed and calculated positions of the asteroids using the HORIZONS system gave standard errors of a single position in the range 0.05 divided by 0.50 ''. Analysis of the (O - C) is given in this paper.Publication The Earth's magnetic field lines and earthquake relations(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2011) Ürüşan, Ahmet Yücel; 114677Earthquake is one of the natural disasters and very important for human life. A lot of people die every year all over the world due to earthquakes. It is very difficult to develop early warning method for earthquakes because of it has 3000 parameters. The earthquake scientists and other people involved are very hard working about this matter. Governments allocate a significant budget for earthquakes. In this study, the earth magnetic field has been researched for early warning. The questions are any tectonic plate movement is effect of the Earth magnetic field lines or changing of the Earth magnetic field lines are effect any tectonic plate. Greater than 7 M earthquakes have been chosen in this study. And 12 years period changing graphics of the earth magnetic field lines where the chosen earthquake locals have been taken.Publication The neural network in coordinate transformation(Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1, Melville, Ny 11747-4501 USA, 2011) Ürüşan, Ahmet Yücel; 114677In international literature, Coordinate operations is divided into two categories. They are coordinate conversion and coordinate transformation. Coordinates converted from coordinate system A to coordinate system B in the same datum (mean origine, scale and axis directions are same) by coordinate conversion. There are two different datum in coordinate transformation. The basis of each datum to a different coordinate reference system. In Coordinate transformation, coordinates are transformed from coordinate reference system A to coordinate referance system B. Geodetic studies based on physical measurements. Coordinate transformation needs identical points which were measured in each coordinate reference system (A and B). However it is difficult (and need a big reserved budget) to measure in some places like as top of mountain, boundry of countries and seaside. In this study, this sample problem solution was researched. The method of learning which is one of the neural network methods, was used for solution of this problem.