Dynamic phase transitions on the kagome Ising ferromagnet

We perform extensive Monte Carlo simulations to investigate the dynamic phase transition properties of the two-dimensional kinetic Ising model on the kagome lattice in the presence of square-wave oscillating magnetic field. Through detailed finite-size scaling analysis, we study universality aspects of the non-equilibrium phase transition. Obtained critical exponents indicate that the two-dimensional kagome-lattice kinetic Ising model belongs to the same universality class with the corresponding Ising model in equilibrium. Moreover, dynamic critical exponent of the local moves used in simulations is determined with high precision. Our numerical results are compatible with the previous ones on kinetic Ising models.Comment: 18 pages, 12 figures. Accepted for publication in Phys. Rev.

Monte Carlo study of the two-dimensional kinetic Blume-Capel model in a quenched random crystal field

We investigate by means of Monte Carlo simulations the dynamic phase transition of the two-dimensional kinetic Blume-Capel model under a periodically oscillating magnetic field in the presence of a quenched random crystal-field coupling. We analyze the universality principles of this dynamic transition for various values of the crystal-field coupling at the originally second-order regime of the corresponding equilibrium phase diagram of the model. A detailed finite-size scaling analysis indicates that the observed nonequilibrium phase transition belongs to the universality class of the equilibrium Ising ferromagnet with additional logarithmic corrections in the scaling behavior of the heat capacity. Our results are in agreement with earlier works on kinetic Ising models.Comment: 25 pages (APS preprint style), 13 figures, 1 tabl

Ising universality in the two-dimensional Blume-Capel model with quenched random crystal field

Using high-precision Monte-Carlo simulations based on a parallel version of the Wang-Landau algorithm and finite-size scaling techniques we study the effect of quenched disorder in the crystal-field coupling of the Blume-Capel model on the square lattice. We mainly focus on the part of the phase diagram where the pure model undergoes a continuous transition, known to fall into the universality class of the pure Ising ferromagnet. A dedicated scaling analysis reveals concrete evidence in favor of the strong universality hypothesis with the presence of additional logarithmic corrections in the scaling of the specific heat. Our results are in agreement with an early real-space renormalization-group study of the model as well as a very recent numerical work where quenched randomness was introduced in the energy exchange coupling. Finally, by properly fine tuning the control parameters of the randomness distribution we also qualitatively investigate the part of the phase diagram where the pure model undergoes a first-order phase transition. For this region, preliminary evidence indicate a smoothening of the transition to second-order with the presence of strong scaling corrections.Comment: 11 pages, 13 figures, minor correction to references appearing in Fig. 1, to be published in Phys. Rev.

Finite temperature magnetic phase transition features of the quenched disordered binary alloy cylindrical nanowire

Thermal and magnetic phase transition properties of a quenched disordered binary alloy cylindrical nanowire of the type A(p)B(1-p) have been elucidated by making use of Monte Carlo simulation based on a local spin update Metropolis algorithm. Magnetic components A with spin-1/2A and B with spin-1 are distributed randomly throughout the cylindrical nanowire with a probability of p and 1-p, respectively. The phase boundary lines, magnetization and also magnetic susceptibility profiles of the system in both presence and absence of a single-ion anisotropy term are investigated. Our Monte Carlo simulation results indicate that the critical behavior of the system sensitively depends on the concentration value of the type-A atoms, the spin-spin exchange interaction strength between unlike magnetic components as well as on the single-ion anisotropy interaction. Finally, a comparison of our observations with those of recently published studies for the clean cylindrical nanowire systems corresponding to p = 0.0 and p = 1.0 cases is presented and it is found that there exist satisfactory agreements. (C) 2017 Elsevier B.V. All rights reserved

Tunning exchange bias in inverted antiferromagnetic/ferromagnetic core/shell nanoparticles by binary alloy shells

A detailed investigation of exchange bias properties of an inverted nanoparticle with an antiferromagnetic core and a ferromagnetic binary alloy shell of the type BxCi, is presented by benefiting from Monte Carlo simulations. Exchange bias displays a non-monotonic behavior with the varying value of the concentration the type-B magnetic components, x. Coercivity exhibits a monotonic or a non-monotonic variation with x depending on the relative strength between unlike magnetic components in the shell. Particular attention has also been given to determine the effects of the cooling field process on the magnetic properties of the nanoparticle. Numerical results obtained in this work present a different physical mechanism and an alternative way for tuning the exchange bias and coercivity of bimagnetic core/shell nanoparticles. (C) 2018 Elsevier B.V. All rights reserved

Thermal and magnetic phase transition properties of a binary alloy spherical nanoparticle: A Monte Carlo simulation study

We have used the Monte Carlo (MC) simulation method with Metropolis algorithm to study the finite temperature phase transition properties of a binary alloy spherical nanoparticle with radius r of the type A(p)B(1)-p. The system consists of two different species of magnetic components, namely, A and B with spins sigma = 1/2 and S =1, respectively. A complete picture of phase diagrams, total magnetizations and susceptibilities in related planes have been presented, and the main roles of the radius of nanoparticle, active concentration value of type-A atoms as well as other system parameters on the thermal and magnetic phase transition features of the considered system have been discussed in detail. Our MC investigations clearly show that it is possible to control the critical characteristic behaviors of the system with the help of adjustable Hamiltonian parameters. (C) 2017 Elsevier B. V. All rights reserved

Numerical study of exchange bias in antiferromagnetic/ferromagnetic core/shell nanoparticles with non-magnetic defects

We perform Monte Carlo simulations for an antiferromagnetic/ferromagnetic core/shell nanoparticle with a doubly inverted structure. We investigate the dependence of the exchange bias field and coercivity on the magnetic dilution of the shell-interface and shell part. It is demonstrated that exchange bias and coercivity can exhibit monotonic or non-monotonic behavior depending on the location of the nonmagnetic components. Also, temperature dependence of the exchange bias and coercivity of the system are studied for a particular defect concentration value. Our results provide an alternative way for tunning the magnetic properties of doubly inverted nanoparticles. (C) 2018 Elsevier B.V. All rights reserved

Türk basınında latin harflerine geçiş ve gazete tasarımına etkileri

ÖZETCumhuriyet ve Vakit gazeteleri üzerinden, harf inkılâbı öncesi ve sonrası için bir sayfa tasarımı okuması yapılacak olan bu tez çalışması, üç bölümden oluşacaktır. Birinci bölümde, matbaanın icâdından harf inkılâbına ve sonrasına değin matbaa/baskı süreçleri ve burada önemli olan hurufata dair bazı malumatlar yer alacaktır. İkinci bölümde, sayfa tasarımı ilkeleri ve etkili haber sunumu için dikkat edilmesi gereken hususlar gibi daha teknik bilgilerle beraber son bölümde yer alacak olan görsellerin ve gazete verilerinin daha iyi yorumlanmasını sağlayacak bazı bilgiler yer alacaktır. Üçüncü bölümde ise, teze konu olan gazetelerin belirlenen tarih aralıklarındaki (İnkılâptan iki ay öncesi ve iki ay sonrası) sayfaları görsel olarak verilerek bu sayfalar üzerindeki incelemeler ve bazı bulgular(haber/görsel ebatları, başlık/spot/metin genişlikleri, puntoları, yazı stilleri vb.) da tablolar hâlinde verilecektir. Verilen bu bilgiler ışığında iki gazete de belirlenen başlıklar çerçevesinde öncelikle ayrı ayrı değerlendirilecektir. Sonuç kısmında ise, harf inkılâbının sayfalar üzerindeki etkileri ve meydana getirdiği tasarımsal değişimler genel olarak derlenecektir. Böylece tam geçiş sürecine, yani inkılâp tarihi etrafındaki o günlere ve gazetelere yakından, ayrıntılı bakılarak olumlu veya olumsuz değişiklikler görülerek, o sürecin tasarım anlayışına ait bir tablo ortaya çıkacaktır.Anahtar kelimeler: Harf inkılâbı, Hurufat, Sayfa tasarımı, Cumhuriyet Gazetesi,Vakit Gazetesi.ABSTRACTThis paper consists of three parts and compares page layouts in the periods before and after the alphabetic revolution by taking samples from Daily Cumhuriyet and Daily Vakit. The first section of the paper covers press/printing procedures from the period printing machines are launched up to the alphabetic revolution and thereafter, and some more information about the typeface used in that period. The second section grounds some more technical points such as page layout principles and matters to be taken into consideration for a more effective reporting along with some information that may help better interpretation of the newspaper data and images included in the last section. Section three visually presents the pages of the daily papers under focus in this study within the defined time period -two months before and after the revolution- and shows some tables to summarize the examination on those pages and findings thereof (sizes of articles/images, length, font size and typeface of headlines/spots/texts, etc.). In the light of the information provided, the two daily papers will first be separately examined within the framework of some titles prescribed and then a general assessment will be made in the conclusion part to cover both of the daily papers in order to compile the effects of the alphabetic revolution on newspaper page layouts and consequent changes in page layouts. A close and detailed look into the days and daily newspapers around the time of the history of revolution is achieved this way in order to capture positive and negative changes for the purpose of having an idea on newspaper layouts pertaining to the transition process. Key words: Alphabetic revolution, typeface, page layout, Daily Cumhuriyet, Daily Vakit

Hysteresis properties of a quenched disordered binary alloy cylindrical nanowire: A Monte Carlo simulation study

We have elucidated the hysteresis features of a quenched disordered binary alloy cylindrical nanowire of the type A(p)B(1-p) by means of Monte Carlo simulation technique. The nanowire system is composed of two types of magnetic components, A with spin-1/2 and B with spin-1, which are distributed randomly on the sites of the nanowire. The dependence of the remanence magnetization (M-r) and coercivity field (H-c) values on the active concentration of type-A magnetic components, p, and the strength of the spin-spin coupling between type-A and -B components have been investigated in a wide range of temperature values. Our Monte Carlo simulation findings suggest that, it is possible to enhance the magnetic properties (i.e., coercivity, remanence as well as hysteresis loops) of the system by changing the concentration of the magnetic components, and also the exchange coupling strength between unlike atoms. Finally, we compare our numerical findings with recent experimental results, and it is found that there exists a qualitatively agreement between them. (C) 2017 Elsevier B.V. All rights reserved