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Neotectonic Characteristics Of The İnönü-Eskişehir Fault System In The Kaymaz (Eskişehir) Region: Influence On The Development Of The Mahmudiye-Çifteler-Emirdağ Basin, Azad Selçuk, Yaşar Ergün Gökten
Neotectonic Characteristics Of The İnönü-Eskişehir Fault System In The Kaymaz (Eskişehir) Region: Influence On The Development Of The Mahmudiye-Çifteler-Emirdağ Basin, Azad Selçuk, Yaşar Ergün Gökten
Turkish Journal of Earth Sciences
The İnönü-Eskişehir Fault System (İEFS) is a NW- to WNW-trending zone of active deformation about 15-25 km wide, 400 km long and characterized predominatly by strike-slip faulting. In this study, the Yörükkaracaören (SE of Eskişehir)-Sivrihisar section of the İEFS was investigated. The system consists of three fault zones, namely the Alpu Fault Zone (AFZ), the Eskişehir Fault Zone (EFZ) and the Orhaniye Fault Zone (OFZ) in the study area. The EFZ is made up mostly of N30°W-trending right-lateral strike-slip fault segments with normal components. However, the AFZ and OFZ are composed of E-W-trending normal and NE- to NW-trending strike-slip fault …
Approximate Groups Iii: The Unitary Case, Emmanuel Breuillard, Ben Green
Approximate Groups Iii: The Unitary Case, Emmanuel Breuillard, Ben Green
Turkish Journal of Mathematics
By adapting the classical proof of Jordan's theorem on finite subgroups of linear groups, we show that every approximate subgroup of the unitary group U_n(C) is almost abelian.
Groupoids, Imaginaries And Internal Covers, Ehud Hrushovski
Groupoids, Imaginaries And Internal Covers, Ehud Hrushovski
Turkish Journal of Mathematics
Let T be a first-order theory. A correspondence is established between internal covers of models of T and definable groupoids within T. We also consider amalgamations of independent diagrams of algebraically closed substructures, and find strong relation between covers, uniqueness for 3-amalgamation, existence of 4-amalgamation, imaginaries of T^\si, and definable groupoids. As a corollary, we describe the imaginary elements of families of finite-dimensional vector spaces over pseudo-finite fields.
On Some New Inequalities For Convex Functions, Mevlüt Tunç
On Some New Inequalities For Convex Functions, Mevlüt Tunç
Turkish Journal of Mathematics
In the present paper we establish some new integral inequalities analogous to the well known Hadamard's inequality by using a fairly elementary analysis.
A Generalization Of Banach's Contraction Principle For Some Non-Obviously Contractive Operators In A Cone Metric Space, Yingxin Guo
Turkish Journal of Mathematics
This paper investigates the fixed points for self-maps of a closed set in a space of abstract continuous functions. Our main results essentially extend and generalize some fixed point theorems in cone metric spaces. An application to differential equations is given.
Geodesicity And Isoclinity Properties For The Tangent Bundle Of The Heisenberg Manifold With Sasaki Metric, Simona Luiza Druta, Paola Piu
Geodesicity And Isoclinity Properties For The Tangent Bundle Of The Heisenberg Manifold With Sasaki Metric, Simona Luiza Druta, Paola Piu
Turkish Journal of Mathematics
We prove that the horizontal and vertical distributions of the tangent bundle with the Sasaki metric are isocline, the distributions given by the kernels of the horizontal and vertical lifts of the contact form \omega on the Heisenberg manifold (H_3,g) to (TH_3,g^S) are not totally geodesic, and the distributions F^H=L(E_1^H,E_2^H) and F^V=L(E_1^V,E_2^V) are totally geodesic, but they are not isocline. We obtain that the horizontal and natural lifts of the curves from the Heisenberg manifold (H_3,g), are geodesics on the tangent bundle endowed with the Sasaki metric (TH_3,g^s), if and only if the curves considered on the base manifold are …
Ion Probe U-Pb Dating Of The Central Sakarya Basement: A Peri-Gondwana Terrane Intruded By Late Lower Carboniferous Subduction/Collision-Related Granitic Rocks, Petek Ayda Ustaömer, Ti̇mur Ustaömer, Alastair Robertson
Ion Probe U-Pb Dating Of The Central Sakarya Basement: A Peri-Gondwana Terrane Intruded By Late Lower Carboniferous Subduction/Collision-Related Granitic Rocks, Petek Ayda Ustaömer, Ti̇mur Ustaömer, Alastair Robertson
Turkish Journal of Earth Sciences
Ion probe dating is used to determine the relative ages of amphibolite-facies meta-clastic sedimentary rocks and crosscutting granitoid rocks within an important 'basement' outcrop in northwestern Turkey. U-Pb ages of 89 detrital zircon grains separated from sillimanite-garnet micaschist from the Central Sakarya basement terrane range from 551 Ma (Ediacaran) to 2738 Ma (Neoarchean). Eighty five percent of the ages are 90-110% concordant. Zircon populations cluster at ~550-750 Ma (28 grains), ~950-1050 Ma (27 grains) and ~2000 Ma (5 grains), with smaller groupings at ~800 Ma and ~1850 Ma. The first, prominent, population (late Neoproterozoic) reflects derivation from a source area …
Petrogenesis Of Late Cretaceous Adakitic Magmatism In The İstanbul Zone (Çavuşbaşı Granodiorite, Nw Turkey), Sabah Yilmaz Şahi̇n, Namik Aysal, Yildirim Güngör
Petrogenesis Of Late Cretaceous Adakitic Magmatism In The İstanbul Zone (Çavuşbaşı Granodiorite, Nw Turkey), Sabah Yilmaz Şahi̇n, Namik Aysal, Yildirim Güngör
Turkish Journal of Earth Sciences
The Çavuşbaşı granodiorite intrudes Ordovician sedimentary rocks in the western part of the İstanbul Zone (NW Turkey). The intrusion is made up mainly of granodiorite, and subordinate tonalite and quartz diorite, and has a granular texture and some special mixing textures such as antirapakivi, blade-shaped biotite, acicular apatite, spongy cellular dissolution/melting plagioclase textures. The main mafic minerals are hornblende and biotite. U-Pb in-situ dating of zircons from two samples via SHRIMP yielded weighted age values of ~68 Ma, suggesting emplacement during the Late Cretaceous. Geochemically the Çavuşbaşı granodiorite resembles adakites with high Sr/Y and La/Yb ratios, low Y and HREE …
The Palu-Uluova Strike-Slip Basin In The East Anatolian Fault System, Turkey: Its Transition From The Palaeotectonic To Neotectonic Stage, Serap Çolak, Ercan Aksoy, Ali̇ Koçyi̇ği̇t, Murat İnceöz
The Palu-Uluova Strike-Slip Basin In The East Anatolian Fault System, Turkey: Its Transition From The Palaeotectonic To Neotectonic Stage, Serap Çolak, Ercan Aksoy, Ali̇ Koçyi̇ği̇t, Murat İnceöz
Turkish Journal of Earth Sciences
The East Anatolian fault system (EAFS) is the 80-km-wide, 700-km-long, NE-trending sinistral strike-slip fault system forming a seismically very active intracontinental transfom fault boundary. It is located between Karlıova County in the northeast and Karataş-Samandağ counties in the southwest, and forms the southeastern boundary of the Anatolian platelet. The Palu-Uluova basin is one of several strike-slip basins located along the EAFS. It is surrounded by several push-ups such as the Karaömerdağı, Mastardağı and Askerdağı push-ups caused by the complexities peculiar to strike-slip faulting. The Palu-Uluova basin consists of three sub-sections: two are NE-trending strike-slip sub-basins, the Uluova and the Palu-Kumyazı …
Early Oligocene Continental Climate Of The Palaeogene Basin (Hungary And Slovenia) And The Surrounding Area, Boglarka Erdei, Torsten Utescher, Lilla Hably, Julia Tamás, Anita Roth-Nebelsick, Michaela Grein
Early Oligocene Continental Climate Of The Palaeogene Basin (Hungary And Slovenia) And The Surrounding Area, Boglarka Erdei, Torsten Utescher, Lilla Hably, Julia Tamás, Anita Roth-Nebelsick, Michaela Grein
Turkish Journal of Earth Sciences
This paper concentrates on the Early Oligocene palaeoclimate of the southern part of Eastern and Central Europe and gives a detailed climatological analysis, combined with leaf-morphological studies and modelling of the palaeoatmospheric CO_2 level using stomatal and \delta^1^3C data. Climate data are calculated using the Coexistence Approach for Kiscellian floras of the Palaeogene Basin (Hungary and Slovenia) and coeval assemblages from Central and Southeastern Europe. Potential microclimatic or habitat variations are considered using morphometric analysis of fossil leaves from Hungarian, Slovenian and Italian floras. Reconstruction of CO_2 is performed by applying a recently introduced mechanistic model. Results of climate analysis …
Palaeoclimate Estimates For Selected Leaf Floras From The Late Pliocene (Reuverian) Of Central Europe Based On Different Palaeobotanical Techniques, Christine Thiel, Stefan Klotz, Dieter Uhl
Palaeoclimate Estimates For Selected Leaf Floras From The Late Pliocene (Reuverian) Of Central Europe Based On Different Palaeobotanical Techniques, Christine Thiel, Stefan Klotz, Dieter Uhl
Turkish Journal of Earth Sciences
To provide quantitative palaeoclimate estimates based on different palaeobotanical techniques for three contemporaneous Pliocene leaf floras, we applied the Coexistence Approach (CoA), leaf margin analysis (LMA), the Climate Leaf Analysis Multivariate Program (CLAMP) and the European Leaf Physiognomic Approach (ELPA). Furthermore, we compared recently published estimates from an additional locality with our data. The leaf physiognomic techniques yield lower mean annual temperatures than the CoA, which is most likely caused by taphonomic biases. Due to these potential biases we are in favour of the CoA as the most reliable method, and its palaeotemperature estimates show similar temperatures for all localities. …
Palaeoclimate Evolution In Siberia And The Russian Far East From The Oligocene To Pliocene – Evidence From Fruit And Seed Floras, Svetlana Popova, Torsten Utescher, Dmitry Gromyko, Angela Bruch, Volker Mosbrugger
Palaeoclimate Evolution In Siberia And The Russian Far East From The Oligocene To Pliocene – Evidence From Fruit And Seed Floras, Svetlana Popova, Torsten Utescher, Dmitry Gromyko, Angela Bruch, Volker Mosbrugger
Turkish Journal of Earth Sciences
The Cenozoic continental deposits of Western Siberia, Eastern Siberia and the Russian Far East are best described on the basis of carpological records. The palaeoclimate evolution has been reconstructed quantitatively (Coexistence Approach) providing inferred data on temperature, precipitation and the mean annual range of these parameters. Climate curves document the transition from very warm and humid conditions in the Late Oligocene via the Middle Miocene Climatic Optimum to a cool temperate climate during the Pliocene. Compared with other time intervals the Miocene climate is the most comprehensively reconstructed. For the Middle Miocene the Siberian and Far Eastern data are combined …
Palaeoclimatic Estimates For The Late Pliocene Based On Leaf Physiognomy From Western Yunnan, China, Sanping Xie, Sun Bainian, Jinyu Wu, Zhicheng Lin, Defei Yan, Liang Xiao
Palaeoclimatic Estimates For The Late Pliocene Based On Leaf Physiognomy From Western Yunnan, China, Sanping Xie, Sun Bainian, Jinyu Wu, Zhicheng Lin, Defei Yan, Liang Xiao
Turkish Journal of Earth Sciences
Based on leaf physiognomy of the Late Pliocene Tuantian megaflora from the Mangbang Formation of Tengchong County in western Yunnan, a quantitative reconstruction of palaeoclimate was performed with Leaf Margin Analysis (LMA) methodology and the Climate-Leaf Analysis Multivariate Program (CLAMP). The latter produced the following parameters: mean annual temperature (MAT) from 17.2 to 17.7°C; warmest month mean temperature (WMMT) from 25 to 25.5°C; coldest month mean temperature (CMMT) from 9.5 to 10.8°C; length of growing season (GRS) from 9.5 to 9.7 months; growing season precipitation (GSP) from 1834.3 to 1901.2 mm; mean monthly growing season precipitation (MMGSP) from 222.4 to …
Silurian Graptolite, Conodont And Cryptospore Biostratigraphy Of The Gülüç Section In Ereğli, Zonguldak Terrane, Nw Anatolia, Turkey, Valeri Sachanski, Mehmet Cemal Göncüoğlu, Iskra Lakova, Ilina Boncheva, Gülnur Saydam-Demi̇ray
Silurian Graptolite, Conodont And Cryptospore Biostratigraphy Of The Gülüç Section In Ereğli, Zonguldak Terrane, Nw Anatolia, Turkey, Valeri Sachanski, Mehmet Cemal Göncüoğlu, Iskra Lakova, Ilina Boncheva, Gülnur Saydam-Demi̇ray
Turkish Journal of Earth Sciences
The studied Gülüç section of the Silurian Fındıklı Formation is situated on the western bank of Gülüç Creek in Ereğli, NW Anatolia, Turkey, in the eastern part of the Zonguldak Terrane. The Gülüç section consists of 3 sedimentary packages: greenish grey limy siltstones, 5-7 m thick (1), overlain by an irregular alternation of black shales and clayey limestones, about 15 m thick (2), and a 6-7 m thick succession of mainly siltstones and sandy limestones (3). A combined biostratigraphy based upon graptolites, cryptospores and conodonts indicates that Package 1 is of Llandovery (Rhuddanian, Aeronian and/or early Telychian) age, Package 2 …
A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş
A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş
Turkish Journal of Electrical Engineering and Computer Sciences
This paper introduces a modified particle swarm algorithm to handle multiobjective optimization problems. In multiobjective PSO algorithms, the determination of Pareto optimal solutions depends directly on the strategy of assigning a best local guide to each particle. In this work, the PSO algorithm is modified to assign a best local guide to each particle by using minimum angular distance information. This algorithm is implemented to determine field-effect transistor (FET) model elements subject to the Pareto domination between the scattering parameters and operation bandwidth. Furthermore, the results are compared with those obtained by the nondominated sorting genetic algorithm-II. FET models are …
Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar
Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar
Turkish Journal of Electrical Engineering and Computer Sciences
The fast changes and developments in the world's economy have substantially increased energy consumption. Consequently, energy planning has become more critical and important. Forecasting is one of the main tools utilized in energy planning. Recently developed computational techniques such as genetic algorithms have led to easily produced and accurate forecasts. In this paper, a natural gas consumption forecasting methodology is developed and implemented with state-of-the-art techniques. We show that our forecasts are quite close to real consumption values. Accurate forecasting of natural gas consumption is extremely critical as the majority of purchasing agreements made are based on predictions. As a …
A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan
A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel hybrid approach for detection of power quality (PQ) disturbances. The proposed hybrid algorithm is based on applications of principle component analysis, discrete wavelet transform, and fast Fourier transform on voltage and current waveforms. The proposed PQ monitoring (PQM) software uses 3-phase voltage and current signals in order to detect possible power disturbances such as voltage sag, flicker, harmonics, transients, DC component, and electromagnetic interference. The test results demonstrate the potential of the proposed hybrid technique for PQM andPQ assessment.
Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş
Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş
Turkish Journal of Electrical Engineering and Computer Sciences
Depending on the evolutions in electronics, wireless sensor networks (WSNs) have been very popular in many areas of human life such as health, industry, and military. This popularity has drawn the attention of many researchers toward WSNs. WSNs are especially favorable in conditions in which it is physically difficult and dangerous for human beings to gather information. Therefore, the lifetime of those networks must be as long as possible, since it would also be infeasible to replace the energy-depleted sensors with new ones, as they may be deployed in such geographical areas that are difficult and dangerous for human beings …
Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya
Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the implementation of broken rotor bar fault detection in an inverter-fed induction motor using motor current signal analysis (MCSA) and prognosis with fuzzy logic. Recently, inverter-fed induction motors have become very popular because of their adjustable speed drive. They have been used in many vital control applications such as rolling mills, variable speed compressors, pumps, and fans. The condition monitoring of these motors can significantly reduce the cost of maintenance in the early detection of faults. In this study, MCSA is applied to an inverter-fed induction motor to detect broken rotor bar faults. The diagnosis of a …
Adaptive Optimization Of Edca Parameters For Improved Qos In Multi-Media Applications, Alparslan Çi̇l, Mehmet Akar, Emi̇n Anarim
Adaptive Optimization Of Edca Parameters For Improved Qos In Multi-Media Applications, Alparslan Çi̇l, Mehmet Akar, Emi̇n Anarim
Turkish Journal of Electrical Engineering and Computer Sciences
IEEE 802.11e Enhanced Distributed Channel Access (EDCA) has been incorporated into the standard as an effective medium access mechanism in order to provide the desired QoS for multimedia applications such as VoIP and IPTV. This paper presents an adaptive optimization algorithm in EDCA which strives to provide improved QoS from both delay and throughput perspectives. As a first step towards this goal, a Markov model of the EDCA mechanism has been introduced, which is subsequently used to compute the estimates of throughput and delay. Based on the analytical model that is validated via real-time simulations in OPNET, a new algorithm …
Hybrid Mpi+Upc Parallel Programming Paradigm On An Smp Cluster, Zeki̇ Bozkuş
Hybrid Mpi+Upc Parallel Programming Paradigm On An Smp Cluster, Zeki̇ Bozkuş
Turkish Journal of Electrical Engineering and Computer Sciences
The symmetric multiprocessing (SMP) cluster system, which consists of shared memory nodes with several multicore central processing units connected to a high-speed network to form a distributed memory system, is the most widely available hardware architecture for the high-performance computing community. Today, the Message Passing Interface (MPI) is the most widely used parallel programming paradigm for SMP clusters, in which the MPI provides programming both for an SMP node and among nodes simultaneously. However, Unified Parallel C (UPC) is an emerging alternative that supports the partitioned global address space model that can be again employed within and across the nodes …
Symmetry And The Order Of Events In Time. The Asymmetrical Order Of Events In Time In A Reversible Energy Converter, Ben-Zion Ginzburg, Randy Wayne
Symmetry And The Order Of Events In Time. The Asymmetrical Order Of Events In Time In A Reversible Energy Converter, Ben-Zion Ginzburg, Randy Wayne
Turkish Journal of Physics
The positive increase of entropy that occurs in irreversible processes has always served as a criterion for distinguishing the past from the future. The unerring ability of the Second Law of Thermodynamics to predict the order of events in time based on a change of entropy in macroscopic systems has led to the concept of the thermodynamical arrow of time. In this paper we analyze a cyclical reversible energy converter, in which thermal energy is converted into useful work without any net change of entropy. While it is usually assumed that time is an outsider in the equations of reversible …
Symmetry And The Order Of Events In Time. A Proposed Identity Of Negative Mass With Antimatter, Randy Wayne
Symmetry And The Order Of Events In Time. A Proposed Identity Of Negative Mass With Antimatter, Randy Wayne
Turkish Journal of Physics
In another paper in this series, we developed a symmetrical theory of mass which describes how systems of positive mass and negative mass will respond to an input of thermal energy. A system composed of positive mass or negative mass will respond to an input of thermal energy in opposite ways. For example, if a system composed of positive mass expands in response to radiation from a hot body, a system composed of negative mass will contract. Likewise, if the system composed of positive mass contracts when brought in communication with a cold body, a system composed of negative mass …
Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani
Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani
Turkish Journal of Physics
Recently proposed model potential of Baria and Jani is used with the exchange and correlation effect of Sarkar et al. to calculate internal energy (Enthalpy), Entropy and Helmholtz free energy of liquid Na, K, Rb and Cs at various temperatures with the variational approach. The parameter of the potential is determined with the standard zero pressure condition. The structure factor derived by Percus-Yevick solution for hard sphere fluids which is characterized by hard sphere diameter \sigma is used. A good agreement between theoretical investigations and experimental findings has confirmed the ability of the model potential to the liquid alkali metals.
Exactly Solvable Potentials From Decemvirate Power Potential, Nilamoni Saikia
Exactly Solvable Potentials From Decemvirate Power Potential, Nilamoni Saikia
Turkish Journal of Physics
A transformation method is presented which consist of a coordinate transformation and a functional transformation that allow generation of exact analytic bound state solutions of the Schrodinger Green's function equation. The method proposed here, which involves the generation of an exact analytic solution from solvable decemvirate power potential within the framework of Green's functions technique, makes it possible to generate a number of solved quantum systems for original quantum systems with multi-term potentials. The generated quantum systems are in general energy dependent with a single normalized eigenstate. A method has been devised to convert a subset of the generated quantum …
The Influence Of Confinements On The Photon Flux Spectra In Amorphous Silicon Quantum Dots, Moafak Cadim Abdulrida, Nidhal Moosa Abdul-Ameer, Shatha Mohammad Abdul-Hakeem
The Influence Of Confinements On The Photon Flux Spectra In Amorphous Silicon Quantum Dots, Moafak Cadim Abdulrida, Nidhal Moosa Abdul-Ameer, Shatha Mohammad Abdul-Hakeem
Turkish Journal of Physics
We have theoretically calculated the photon flux of radiative recombination in amorphous silicon quantum dots (a-SiQDs) at room temperature. These quantum dots have been ranged in their diameter 1 to 4 nm. The convolution of probability density function of deepest energy states of conduction P_C(E) and valence P_V(E) bands within the capture volume was adopted. The behavior of this function can be classified into four regions according to the quantum dot size. The effect of spatial and quantum confinements on the peak value of photon flux must be taken into account. We found that a blue shift is classified by …
Te Surface Waves In Dielectric Slab Sandwiched Between Lhm Slabs, Ass'ad I. Ass'ad, Hassan S. Ashour
Te Surface Waves In Dielectric Slab Sandwiched Between Lhm Slabs, Ass'ad I. Ass'ad, Hassan S. Ashour
Turkish Journal of Physics
In this work, the dispersion relation for TE surface waves has been derived for a slab waveguide constructed from a dielectric material slab sandwiched between two thick layers of left-handed material (LHM). The dispersion relation and the power flow were numerically solved for a given set of parameters: the structural factor, dielectric slab thickness, and the operating frequency on the effective refractive index and power flow. We found that the wave effective refractive index decreases with thickness increase as well as increase in frequency. We found that the effective refractive index increases slightly with increase of structural factor. Also, the …
Dynamics And Noise Of Fiber-Grating Semiconductor Lasers Affected By The Line-Width Enhancement Factor, Salah Abdulrhmann
Dynamics And Noise Of Fiber-Grating Semiconductor Lasers Affected By The Line-Width Enhancement Factor, Salah Abdulrhmann
Turkish Journal of Physics
This paper numerically investigates the effect of the line-width enhancement factor on the dynamics and the intensity noise of InGaAs/InP lasers pumping in the wavelength of 980 nm at the strong optical feedback limit. The investigation is performed based on an improved time-delay rate equation model of a single-mode laser. The analyses are performed in terms of the temporal trajectory of the laser intensity, bifurcation diagram, relative intensity noise and injection current. The simulation results indicate that the laser, under strong optical feedback, mainly operates in CW, pulsation or chaos operation depending on the line-width enhancement factor and injection current …
Behavior Of Temperature Dependence Of Permeability Curves At Different Stages Of Crystallizations Of Nanocrystalline Fe_{70.5}Cr_3cu_1nb_3si_{13.5}B_9, Saadni Islam, Kazi Hanium Maria, Shamima Choudhury, Mohammad Abdul Hakim, Dilip Kumar Saha
Behavior Of Temperature Dependence Of Permeability Curves At Different Stages Of Crystallizations Of Nanocrystalline Fe_{70.5}Cr_3cu_1nb_3si_{13.5}B_9, Saadni Islam, Kazi Hanium Maria, Shamima Choudhury, Mohammad Abdul Hakim, Dilip Kumar Saha
Turkish Journal of Physics
Nanocrystalline amorphous ribbons of composition Fe_{70.5}Cr_3Cu_1Nb_3Si_{13.5}B_9 prepared by rapid solidification technique have been studied in the present work. Amorphicity of the ribbons has been confirmed by X-ray diffraction. Crystallization temperatures were identified by X-ray diffraction and crystallization products were analyzed by XRD. When annealed below the crystallization temperature, i.e. when the sample is in amorphous state, temperature dependence of permeability curves were characterized by sharp increase of permeability and subsequent fall to lower value near ferro-paramagnetic transition temperature, which is typical Hopkinson effect for soft ferromagnetic single phase material. Under devitrification, when the sample is in a two phase state, …
A Fresh Look At Thermal Field Emission From Tungsten Tip, Ahmed Abdurrahman Ahmed Al-Tabbakh
A Fresh Look At Thermal Field Emission From Tungsten Tip, Ahmed Abdurrahman Ahmed Al-Tabbakh
Turkish Journal of Physics
Electron emission from clean tungsten tips has been investigated at different temperatures and applied electric field. Emission mechanism is analyzed on the basis of the Fowler-Nordheim (FN) model and a parameter extraction model based on elimination of field enhancement factor. The suggested extraction model of the physical and geometrical parameters is found fairly adequate to resolving the apparently confusing behavior of these parameters and shedding light on the emission mechanism. The observed linear FN plots at low temperatures confirm the predominating effect of the applied field on the electron emission. At elevated temperatures, emission is found to fall in the …