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Search Results: 1 - 10 of 179 matches for " Aytap Sezer "
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Fe-rich ejecta in the supernova remnant G352.7-0.1 with Suzaku
Aytap Sezer,Fatma Gok
Physics , 2014, DOI: 10.1088/0004-637X/790/1/81
Abstract: In this work, we present results from a $\sim$201.6 ks observation of G352.7$-$0.1 by using the X-ray Imaging Spectrometer onboard {\it Suzaku} X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of $N_{\rm H}$ $\sim$ 3.3$\times$10$^{22}$ cm$^{-2}$. The soft component is characterized by an electron temperature of $kT_{\rm e}$ $\sim$ 0.6 keV, an ionization time-scale of $\tau$ $\sim$ 3.4$\times$10$^{11}$ cm$^{-3}$ s, and enhanced Si, S, Ar, and Ca abundances. The hard component has $kT_{\rm e}$ $\sim$ 4.3 keV, $\tau$ $\sim$ 8.8$\times$10$^{9}$ cm$^{-3}$ s, and enhanced Fe abundance. The elemental abundances of Si, S, Ar, Ca, and Fe are found to be significantly higher than the solar values that confirm the presence of ejecta. We detected strong Fe K-shell emission and determined its origin to be the ejecta for the first time. The detection of Fe ejecta with a lower ionization time-scale favor Type Ia origin for this remnant.
The Relation Between the Surface Brightness and the Diameter for Galactic Supernova Remnants
Oktay H. Guseinov,Askin Ankay,Aytap Sezer,Sevinc O. Tagieva
Physics , 2003, DOI: 10.1080/1055679021000034160
Abstract: In this work, we have constructed a relation between the surface brightness ($\Sigma$) and diameter (D) of Galactic C- and S-type supernova remnants (SNRs). In order to calibrate the $\Sigma$-D dependence, we have carefully examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of the ambient medium) properties of the remnants and, taking into account also the distance values given in the literature, we have adopted distances for some of the SNRs which have relatively more reliable distance values. These calibrator SNRs are all C- and S-type SNRs, i.e. F-type SNRs (and S-type SNR Cas A which has an exceptionally high surface brightness) are excluded. The Sigma-D relation has 2 slopes with a turning point at D=36.5 pc: $\Sigma$(at 1 GHz)=8.4$^{+19.5}_{-6.3}$$\times10^{-12}$ D$^{{-5.99}^{+0.38}_{-0.33}}$ Wm$^{-2}$Hz$^{-1}$ster$^{-1}$ (for $\Sigma$$\le3.7\times10^{-21}$ Wm$^{-2}$Hz$^{-1}$ster$^{-1}$ and D$\ge$36.5 pc) and $\Sigma$(at 1 GHz)=2.7$^{+2.1}_{-1.4}$$\times$ 10$^{-17}$ D$^{{-2.47}^{+0.20}_{-0.16}}$ Wm$^{-2}$Hz$^{-1}$ster$^{-1}$ (for $\Sigma$$>3.7\times10^{-21}$ Wm$^{-2}$Hz$^{-1}$ster$^{-1}$ and D$<$36.5 pc). We discussed the theoretical basis for the $\Sigma$-D dependence and particularly the reasons for the change in slope of the relation were stated. Added to this, we have shown the dependence between the radio luminosity and the diameter which seems to have a slope close to zero up to about D=36.5 pc. We have also adopted distance and diameter values for all of the observed Galactic SNRs by examining all the available distance values presented in the literature together with the distances found from our $\Sigma$-D relation.
Searching for Overionized Plasma in the Gamma-ray Emitting Supernova Remnant G349.7$+$0.2
Tülün Ergin,Aytap Sezer,Lab Saha,Pratik Majumdar,Fatma G?k,E. Nihal Ercan
Physics , 2015, DOI: 10.1088/0004-637X/804/2/124
Abstract: G349.7$+$0.2 is a supernova remnant (SNR) expanding in a dense medium of molecular clouds and interacting with clumps of molecular material emitting gamma rays. We analyzed the gamma-ray data of Large Area Telescope on board Fermi Gamma Ray Space Telescope and detected G349.7$+$0.2 in the energy range of 0.2$-$300 GeV with a significance of $\sim$13$\sigma$ showing no extended morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray emission dominantly originates from the decay of neutral pions, where the protons follow a broken power-law distribution with a spectral break at $\sim$12 GeV. To search for features of radiative recombination continua in the eastern and western regions of the remnant, we analyzed the Suzaku data of G349.7$+$0.2 and found no evidence for overionized plasma. In this paper we discuss possible scenarios to explain the hadronic gamma-ray emission in G349.7$+$0.2 and the mixed morphology nature of this SNR.
Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391
Tülün Ergin,Aytap Sezer,Lab Saha,Pratik Majumdar,Anshu Chatterjee,Arif Bay?rl?,E. Nihal Ercan
Physics , 2014, DOI: 10.1088/0004-637X/790/1/65
Abstract: A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MC) has been discovered as strong GeV gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MC. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3 $-$ 10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of $\sim$ 18 $\sigma$ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.
The effects of music on anger and psychological symptoms
International Journal of Human Sciences , 2011,
Abstract: In this study, individuals who prefer to listen to music in everyday life tried to determine whether the effects on anger and psychological states. The sample group consisted of total 288 individuals who 188 girl and 100 men. The data used in this study obtained from The State Trait Anger Scale and Anger Expression Scale and Brief Symptoms Inventory. Analysis of the data, mean and standard deviation values, and one-way analysis of variance (One Way ANOVA) were used. As a result of the findings of this study, individuals who prefer to listen to music in everyday life situations of anger and psychological symptoms revealed that over a significant effect.
Women employed in textile sector in Turkey and their problems: (Istanbul-Adana-Denizli-Sivas and Tekirda Province samples)
Sezer Ayan
International Journal of Human Sciences , 2011,
Abstract: Purpose of the study is to determine the problems of women working in textile factories as parallel to the characteristics of female labor in Turkey and the factors affecting these problems. With this purpose, 564 women working in textile factories in Istanbul, Adana, Denizli, Tekirda and Sivas provinces were included in the study. It was determined according to the results obtained that factors affecting the problems women encounter in working life in a statistically significant way (P>0,25) are monthly income of the family, form of the family, number of members of the household, quality of the intra-family relationships, daily working hours, job satisfaction, relationships of the employee with managers and way of making decisions inside the family, respectively.
Birinci Dünya Sava ’nda Hilal-i Ahmer Cemiyeti’nin Sa l k Alan ndaki Faaliyetleri/// The Medical Activities of the Red Crescent Society during World War I
History Studies : International Journal of History , 2012,
Abstract: This article covers the activities of the Red Crescent Society in the Ottoman Empire during World War I. The society opened hospitals and convalescent hospital to serve wounded and sick soldiers but they also served civilians in case of a need. The Red Crescent Society aimed to help the military and the civilians to prevent deaths caused by the spread of epidemics and famine and cure the injuries and ease pain and suffering. The activities displayed by the authorities of Red Crescent under the dire circumstances were very praiseworthy.
Surgical Management of Secondary Hyperparathyroidism in Patients with End-Stage Renal Disease: Surgical Approaches and Report of Cases
Atakan SEZER
Trakya Universitesi Tip Fakultesi Dergisi , 2009,
Abstract: Objectives: End-stage renal disease is a worldwide public health problem. While the survival time of the patients extends, additional pathologies such as secondary hyperparathyroidism occurs. The aim of the study is to review the surgical approaches to secondary hyperparathyroidism and present our experiences.Patients and Methods: This retrospective study included five male patients (mean age 38.6 years) who were operated on for chronic renal failure between 2004 and 2008. The data of patients were collected from hospital records.Results: The mean duration of hemodialysis was 106.8 months. All patients had ultrasonography and scintigraphy preoperatively. The mean value of preoperative and postoperative serum PTH was 2097 ng/ml and 36.5 ng/dl, Ca 11.48 mg/dl and 6.2 mg/dl, P 7.5 mg/dl and 4.4 mg/dl, ALP 527 IU/L and 89 IU/L. Total parathyroidectomy and sternocleidomastoid muscle autotransplantation was performed in all patients and one patient had right thyroidectomy in addition. Postoperatively, all patients received oral calcium carbonate and calcitriol. No serious postoperative complications occurred in any of these cases. The duration of hospitalization was 4.6 days on the average. Serum PTH was kept constantly below 300 ng/L in all cases in follow-up and no recurrent hyperparathyroidism was detected.Conclusion: Although there are many types of surgery techniques in treatment of secondary hyperparathyroidism, total parathyroidectomy with autografting is the most accepted procedure with low recurrent and complication rate in end-stage renal disease patients.
Examining of Teacher Burnout Level in Terms of Some Variables
Fahri Sezer
International Online Journal of Educational Sciences , 2012,
Abstract: In this study, the statuses of teachers’ burnout are discussed in terms of size emotional exhaustion, depersonalization and personal accomplishment. And tried to determine what are the factors affecting the burnout. In the study “Maslach Burnout Inventory" as measuring tools to determine the status of teachers’ burnout was used. Analysis of data was used t test and one-way ANOVA. The sample of research is consist of 192 teachers who 114 women and 78 men that working in different training positions. The findings revealed that gender, education level, profession, seniority, number of students taught in classrooms, teachers' levels of academic work (primary 1st stage, 2nd stage, and secondary education) and whether teachers have a child or not had an influence on burnout. 2012 IOJES. All rights reserved
Bounds for the Largest Laplacian Eigenvalue of Weighted Graphs
Sezer Sorgun
International Journal of Combinatorics , 2013, DOI: 10.1155/2013/520610
Abstract: Let be weighted graphs, as the graphs where the edge weights are positive definite matrices. The Laplacian eigenvalues of a graph are the eigenvalues of Laplacian matrix of a graph . We obtain two upper bounds for the largest Laplacian eigenvalue of weighted graphs and we compare these bounds with previously known bounds. 1. Introduction Let be simple graphs, as graphs which have no loops or parallel edges such that is a finite set of vertices and is a set of edges. A weighted graph is a graph each edge of which has been assigned to a square matrix called the weight of the edge. All the weight matrices are assumed to be of same order and to be positive matrix. In this paper, by “weighted graph” we mean “a weighted graph with each of its edges bearing a positive definite matrix as weight,” unless otherwise stated. The notations to be used in paper are given in the following. Let be a weighted graph on vertices. Denote by the positive definite weight matrix of order of the edge , and assume that . We write if vertices and are adjacent. Let . be the weight matrix of the vertex . The Laplacian matrix of a graph is defined as , where The zero denotes the zero matrix. Hence is square matrix of order . Let denote the largest eigenvalue of . In this paper we also use to avoid the confusion that is the spectral radius of matrix. If is the disjoint union of two nonempty sets and such that every vertex in has the same and every vertex in has the same , then is called a weight-semiregular graph. If in weight semiregular graph, then is called a weighted-regular graph. Upper and lower bounds for the largest Laplacian eigenvalue for unweighted graphs have been investigated to a great extent in the literature. Also there are some studies about the bounds for the largest Laplacian eigenvalue of weighted graphs [1–3]. The main result of this paper, contained in Section 2, gives two upper bounds on the largest Laplacian for weighted graphs, where the edge weights are positive definite matrices. These upper bounds are attained by the same methods in [1–3]. We also compare the upper bounds with the known upper bounds in [1–3]. We also characterize graphs which achieve the upper bound. The results clearly generalize some known results for weighted and unweighted graphs. 2. The Known Upper Bounds for the Largest Laplacian Eigenvalue of Weighted Graphs In this section, we present the upper bounds for the largest Laplacian eigenvalue of weighted graphs and very useful lemmas to prove theorems. Theorem 1 (Horn and Johnson [4]). Let be Hermitian, and let the eigenvalues of be
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