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Articles 1 - 30 of 694
Full-Text Articles in Physical Sciences and Mathematics
Geochemical, Microthermometric, And Isotopic Constraints On The Origin Of Fluorite Deposits In Central Anatolia, Turkey, Peli̇n Coşanay, Ece Kirat, Ni̇hal Çevi̇k, Ceyda Kizilkanat, Hali̇m Mutlu, Şükrü Koç
Geochemical, Microthermometric, And Isotopic Constraints On The Origin Of Fluorite Deposits In Central Anatolia, Turkey, Peli̇n Coşanay, Ece Kirat, Ni̇hal Çevi̇k, Ceyda Kizilkanat, Hali̇m Mutlu, Şükrü Koç
Turkish Journal of Earth Sciences
We investigate rare earth element geochemistry, microthermometric characteristics, and radiogenic isotope systematics of fluorites and stable isotope compositions of gangue minerals from several fluorite deposits in central Turkey. In the deposits, fluorite is the main ore mineral and it is accompanied by quartz, calcite, and minor pyrite and barite. Veins are represented by three different fluorite types based on their color. Total REY contents of fluorites are highly variable, ranging from 24 to 693 ppm. LREE concentrations of fluorites of all colors are similar but medium and heavy REE abundances of green fluorites are nearly an order of magnitude greater …
Paleoenvironment Of The Late Oligocene From The Kağızman-Tuzluca Basin (Northeastern Anatolia) Based On The Micro- And Macrofloras, Mi̇ne Sezgül Kayseri̇ Özer, Recep Hayretti̇n Sancay, Şevket Şen, Koray Sözeri̇, Gregoire Métais, Turhan Ayyildiz, Baki̇ Erdoğan Varol
Paleoenvironment Of The Late Oligocene From The Kağızman-Tuzluca Basin (Northeastern Anatolia) Based On The Micro- And Macrofloras, Mi̇ne Sezgül Kayseri̇ Özer, Recep Hayretti̇n Sancay, Şevket Şen, Koray Sözeri̇, Gregoire Métais, Turhan Ayyildiz, Baki̇ Erdoğan Varol
Turkish Journal of Earth Sciences
The Kağızman-Tuzluca Basin in East Anatolia is still poorly documented for its stratigraphy and in particular its paleofloral assemblages. In this study, the microfloras from the Kağızman-Kötek and Kömürlü areas and the macroflora from the Tuzluca area in this basin have been defined to overcome this deficiency. Sedimentary sequences of the Kağızman-Kömürlü area have been deposited in terrestrial conditions different from the sequences of the Kağızman-Kötek and Tuzluca areas, which were deposited in brackish conditions near a shallow marine environment. Paleovegetation in eastern Anatolia is represented by mixed mesophytic and coniferous forests restricted to high and middle altitudes (e.g. Pinus, …
The Discovery Of A Low-Angle Normal Fault In The Taurus Mountains: The İvriz Detachment And Implications Concerning The Cenozoic Geology Of Southern Turkey, Gürol Seyi̇toğlu, Veysel Işik, Esra Gürbüz, Alper Gürbüz
The Discovery Of A Low-Angle Normal Fault In The Taurus Mountains: The İvriz Detachment And Implications Concerning The Cenozoic Geology Of Southern Turkey, Gürol Seyi̇toğlu, Veysel Işik, Esra Gürbüz, Alper Gürbüz
Turkish Journal of Earth Sciences
The İvriz detachment fault has been determined on the southern border of the Ulukışla basin separating the metamorphic Bolkar Group of the Taurus Mountains and the Paleocene-Lower Eocene Halkapınar formation of basin deposits. The fault dips towards the north and has kinematic indicators (asymmetric grain/grain aggregate porphyroclasts, oblique foliation, and S-C fabrics), suggesting a top-to-the-N-NE sense of shearing. The clastic material originating from the Bolkar Group in the sedimentary units of the Ulukışla basin demonstrates that the detachment fault could have been be active during Latest Cretaceous-Eocene times. The İvriz detachment may have initiated as part of a high-angle breakaway …
The Impact Of Eustasy, Tectonics, And Paleoclimate On The Dolomitization Of The Syn-Rift Neogene Carbonate Platforms In The Red Sea Coastal Area, Egypt, Abdallah Mohammed Hassan
The Impact Of Eustasy, Tectonics, And Paleoclimate On The Dolomitization Of The Syn-Rift Neogene Carbonate Platforms In The Red Sea Coastal Area, Egypt, Abdallah Mohammed Hassan
Turkish Journal of Earth Sciences
A very significant quantity of dolomites and dolomitic limestones of variable origins occurs in the syn-rift Neogene carbonate platforms of the NW Red Sea coast and the Gulf of Suez. These are more common in the Um Diheisi Member of the Ranga Formation (early Miocene), the Um Mahara Formation (middle Miocene), the Um Gheig Formation (late Miocene), and the Dashet El Dabaa Member of the Shagra Formation (Pliocene). Based on their stratigraphic distribution, petrography, and cathodoluminescent characteristics, as supported by geochemical data, syn-rift irregular morphotectonic relief, and the eustasy, four distinct types of dolomites have been identified and were interpreted …
Crustal S-Wave Structure Around The Lake Van Region (Eastern Turkey) From Interstation Rayleigh Wave Phase Velocity Analyses, Hakan Çinar, Hamdi̇ Alkan
Crustal S-Wave Structure Around The Lake Van Region (Eastern Turkey) From Interstation Rayleigh Wave Phase Velocity Analyses, Hakan Çinar, Hamdi̇ Alkan
Turkish Journal of Earth Sciences
This study focuses on the average crustal and the upper mantle structure throughout the Lake Van region of eastern Turkey. The study aimed to investigate the structure with the fundamental mode interstation Rayleigh wave phase velocities from the local and the regional earthquakes recorded by Kandilli Observatory and Earthquake Research Institute stations. Considering back azimuth differences of each source and station path, six different broadband station pairs and 27 earthquakes were selected to determine the 1-D shear-wave velocity structures throughout the region by using an interstation method (slant stacking technique). The linearized least squares algorithm was used to obtain the …
Marine Effects On Vertical Electrical Soundings Along Shorelines, Emi̇n Uğur Ulugergerli̇
Marine Effects On Vertical Electrical Soundings Along Shorelines, Emi̇n Uğur Ulugergerli̇
Turkish Journal of Earth Sciences
Onshore applications of direct current resistivity (DCR) along shorelines suffer a short-circuit-like phenomenon due to electrical current flowing through a more conductive body of water rather than ground. Our study of the numerical simulation of DCR data with a three-dimensional forward model demonstrated that the apparent resistivity was reduced as a function of the sea depth and the distance of measurement site to the shoreline. Furthermore, it was concluded that the "marine effects" on DCR data (i.e. reduction in apparent resistivity) become nonnegligible as the ratio of half-electrode expansion (AB/2) to the distance to the shoreline is larger than one. …
Active Faults In The Anatolian-Aegean Plate Boundary Region With Nubia, Ali̇ Değer Özbakir, Rob Govers, Rinus Wortel
Active Faults In The Anatolian-Aegean Plate Boundary Region With Nubia, Ali̇ Değer Özbakir, Rob Govers, Rinus Wortel
Turkish Journal of Earth Sciences
Convergence of the Africa, Arabia, and Eurasia plates and the westward escape of Anatolia have resulted in an evolving plate boundary zone in the Eastern Mediterranean. The current location and nature of the plate boundary between the Anatolian and the African plate is difficult to trace due to the scattered crustal earthquakes and the absence of deep ones. We examine various types and locations for the plate boundary as constrained by seismicity, seismic reflection studies, tomographic studies, and geodetic measurements and we use a spherical plane stress finite element model to test these possibilities. In our regional model, we impose …
Maastrichtian-Thanetian Planktonic Foraminiferal Biostratigraphy And Remarks On The K-Pg Boundary In The Southern Kocaeli Peninsula (Nw Turkey), Volkan Sarigül, Aynur Hakyemez, Okan Tüysüz, Şengül Can Genç, İsmai̇l Ömer Yilmaz, Ercan Özcan
Maastrichtian-Thanetian Planktonic Foraminiferal Biostratigraphy And Remarks On The K-Pg Boundary In The Southern Kocaeli Peninsula (Nw Turkey), Volkan Sarigül, Aynur Hakyemez, Okan Tüysüz, Şengül Can Genç, İsmai̇l Ömer Yilmaz, Ercan Özcan
Turkish Journal of Earth Sciences
The Kocaeli Peninsula (NW Turkey) provides one of the best exposed deep marine Upper Cretaceous-Palaeocene sections in north-western Anatolia. The biostratigraphic framework from three sections, namely Belen, Bulduk, and Toylar, in the southern part of the Kocaeli Peninsula is established by means of planktonic foraminifera. A very rich planktonic foraminiferal assemblage analysed both in thin sections and washed residues records a biozonation ranging from the Contusotruncana contusa (CF6) Zone (Maastrichtian) to the Globanomalina pseudomenardii (P4) Zone (Thanetian). Although a major part of the biozones in the studied interval is clearly defined, the upper three zones (CF1-3) of the latest Maastrichtian …
Sulfur Isotope Characteristics Of The Permian Vhms Deposits In Tasik Chini District, Central Belt Of Peninsular Malaysia, Mohd Basril Iswadi Basori, Khin Zaw, Robert Ross Large, Wan Fuad Wan Hassan
Sulfur Isotope Characteristics Of The Permian Vhms Deposits In Tasik Chini District, Central Belt Of Peninsular Malaysia, Mohd Basril Iswadi Basori, Khin Zaw, Robert Ross Large, Wan Fuad Wan Hassan
Turkish Journal of Earth Sciences
Sulfur isotope data from sulfide and sulfate minerals have been measured from the two typical examples of the Permian volcanic-hosted massive sulfide (VHMS) deposits at the Tasik Chini district in the Central Belt of Peninsular Malaysia. In this study, we present the sulfur isotope data for 33 sulfide minerals and 23 barite samples from two VHMS deposits in the Tasik Chini district. Sulfides show a narrow range of sulfur values from -2.9%o to +8.30%o, which can be interpreted to be derived from a mixed sulfur source of reduced seawater sulfate with the possible addition of magmatic sulfur. Sulfate sulfur in …
Robust Adaptive Fuzzy Control Of A Three-Phase Active Power Filter Based On Feedback Linearization, Shixi Hou, Juntao Fei
Robust Adaptive Fuzzy Control Of A Three-Phase Active Power Filter Based On Feedback Linearization, Shixi Hou, Juntao Fei
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a robust adaptive fuzzy control system using feedback linearization is proposed for a three-phase active power filter (APF). The APF system is divided into two separate loops: the current dynamic inner loop and the DC voltage dynamic outer loop. Adaptive fuzzy tracking control using feedback linearization is employed for the current dynamic inner loop to overcome the drawbacks of the conventional method. The proposed controller can ensure proper tracking of the reference current and impose desired dynamic behavior, giving robustness and insensitivity to parameter variations. Adaptive fuzzy proportional-integral control is applied to the DC voltage dynamics outer …
Gica: Imperialist Competitive Algorithm With Globalization Mechanism For Optimization Problems, Yousef Abdi, Mahmoud Lak, Yousef Seyfari
Gica: Imperialist Competitive Algorithm With Globalization Mechanism For Optimization Problems, Yousef Abdi, Mahmoud Lak, Yousef Seyfari
Turkish Journal of Electrical Engineering and Computer Sciences
The imperialist competitive algorithm (ICA) is a recent global search strategy developed based on human social evolutionary phenomena in the real world. However, the ICA has the drawback of trapping in local optimum solutions when used for high-dimensional or complex multimodal functions. In order to deal with this situation, in this paper an improved ICA, named GICA, is proposed that can enhance ICA performance by using a new assimilation method and establishing a relationship between countries inspired by the globalization concept in the real world. The proposed algorithm is evaluated using a set of well-known benchmark functions for global optimization. …
Adaptive Control Of Pure-Feedback Systems In The Presence Of Parametric Uncertainties, Mehrnoosh Asadi, Heydar Toossian Shandiz
Adaptive Control Of Pure-Feedback Systems In The Presence Of Parametric Uncertainties, Mehrnoosh Asadi, Heydar Toossian Shandiz
Turkish Journal of Electrical Engineering and Computer Sciences
The purpose of this study is to investigate an adaptive control approach for completely nonaffine pure-feedback systems with linear/nonlinear parameterization. In this approach, the parameter separation technique and the idea of the positive function of linearly connected parameters are coupled effectively with the combination of backstepping and time-scale separation. Subsequently, a fast dynamical equation is derived from the original subsystem, where the solution is sought to approximate the corresponding ideal virtual/actual control inputs. Furthermore, the adaptation law of unknown parameters can be derived based on Lyapunov theory in the backstepping technique and there is no need to design a state …
An Effective Empirical Approach To Voip Traffic Classification, Nazar Abbas Saqib, Yaqoot Shakeel, Moazzam Ali Khan, Hasan Mehmood, Muhammad Zia
An Effective Empirical Approach To Voip Traffic Classification, Nazar Abbas Saqib, Yaqoot Shakeel, Moazzam Ali Khan, Hasan Mehmood, Muhammad Zia
Turkish Journal of Electrical Engineering and Computer Sciences
It is beneficial for telecommunication authorities and Internet service providers (ISPs) to classify and detect voice traffic. It can help them to block unsubscribed users from using their services, which saves them huge revenues. Voice packets can be detected easily, but it becomes complicated when the application or port information in the packet header is hidden due to some secure mechanism such as encryption. This work provides effective voice packet classification and detection based on behavioral and statistical analysis, which is independent of any application, security protocol, or encryption mechanism. First we have made initial assessments through packet feature analysis …
Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken
Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a dual broadband antenna is proposed for WLAN communication modules supported by the IEEE 802.11 ac/b/g/n standard. The antenna design is based on two interspaced electrically small split-ring resonators, each of which is directly fed through the stepped impedance microstrip line with an optimized electromagnetic coupling distance in between. The proposed dual band antenna operates in the lower frequency band from 2.3 GHz up to 3 GHz with 2.65 GHz center frequency (26.4 % bandwidth) and in the higher frequency band from 4.7 GHz up to 6 GHz with 5.35 GHz center frequency (24.3% bandwidth). The radiating …
Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal
Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal
Turkish Journal of Electrical Engineering and Computer Sciences
An electroencephalogram (EEG) is an electrical signal in microvolts captured noninvasively from the brain, which provides important and unique information about the brain. The frequency of an EEG signal lies between 0 and 100 Hz. Decomposition of an EEG signal into various bands such as alpha, beta, delta, theta, and gamma is essential in seizure-related studies. EEGs play a key role in the diagnosis of epileptic seizures and neurological disorders. In this paper, multiple wavelet families for decomposition and reconstruction are explored and are compared based on risk functions and reconstruction measures. While dealing with the wavelets it is a …
Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe
Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a dynamic model is developed for high-voltage circuit breakers to extract fault features and causes. Lagrange's method is applied using geometric equations of mechanism components to write the model. Unlike previous approaches, the proposed method reveals and analyzes all types of circuit breaker operating mechanism faults. Early fault detection, which is a vital requirement of the fault diagnosis system, becomes feasible by keeping track of changes in the contact travel curve in the proposed model. Resulting faults in the travel curve are analyzed mathematically in order to find out the exact origin of the fault. Field test …
Analysis Of Feature Detector And Descriptor Combinations With A Localization Experiment For Various Performance Metrics, Ertuğrul Bayraktar, Pinar Boyraz
Analysis Of Feature Detector And Descriptor Combinations With A Localization Experiment For Various Performance Metrics, Ertuğrul Bayraktar, Pinar Boyraz
Turkish Journal of Electrical Engineering and Computer Sciences
The purpose of this study is to provide a detailed performance comparison of feature detector/descriptor methods, particularly when their various combinations are used for image-matching. The localization experiments of a mobile robot in an indoor environment are presented as a case study. In these experiments, 3090 query images and 127 dataset images were used. This study includes five methods for feature detectors (features from accelerated segment test (FAST), oriented FAST and rotated binary robust independent elementary features (BRIEF) (ORB), speeded-up robust features (SURF), scale invariant feature transform (SIFT), and binary robust invariant scalable keypoints (BRISK)) and five other methods for …
Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications, Emre Avci, Mehmet Uçar
Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications, Emre Avci, Mehmet Uçar
Turkish Journal of Electrical Engineering and Computer Sciences
The 3-level T-type neutral point clamped (T-NPC) inverter has become the most popular multilevel inverter used in low-voltage applications. However, the realization of a bidirectional switch located at the midpoint leg of the T-NPC inverter is achieved using two insulated gate bipolar transistors (IGBTs) with two antiparallel diodes. Power dissipation in these switches is high since there are two semiconductors (an IGBT and a diode) in the current path at the midpoint leg. Switch losses can be reduced and thus the highest conversion efficiency can be achieved if the bidirectional switches in the T-NPC inverter are replaced by highly efficient …
Extraction Of Geometric And Prosodic Features From Human-Gait-Speech Data For Behavioral Pattern Detection: Part I, Raj Kumar Patra, Tilendra Shishir Sinha, Ravi Prakash Dubey
Extraction Of Geometric And Prosodic Features From Human-Gait-Speech Data For Behavioral Pattern Detection: Part I, Raj Kumar Patra, Tilendra Shishir Sinha, Ravi Prakash Dubey
Turkish Journal of Electrical Engineering and Computer Sciences
In this work, we extract prosodic features from subjects while they are talking while walking using human-gait-speech data. These human-gait-speech data are separated into 1D data (human-speech) and 2D data (human-gait) using the adaptive-lifting scheme of wavelet transform. We carry out extraction of prosodic features from human-speech data, such as speech duration, pitch, speaking rate, and speech momentum, using five different natural languages (Hindi, Bengali, Oriya, Chhattisgarhi, and English) for the detection of behavioral patterns. These behavioral patterns form real-valued measured parameters, stored in a knowledge-based model called the human-gait-speech model. Extraction of geometrical features from human-gait data, such as …
Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes, Obada Abdallah, Ammar Abu Hudrouss
Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes, Obada Abdallah, Ammar Abu Hudrouss
Turkish Journal of Electrical Engineering and Computer Sciences
Space-time code can be implemented in wireless relay networks when all relays cooperate to generate the code at the receiver. In this case, it is called distributed space-time code. If the channel response changes very quickly, the idea of differential space-time coding is needed to overcome the difficulty of updating the channel state information at the receiver. As a result, the transmitted signal can be demodulated without any knowledge of the channel state information at the relays or the receiver. In this paper, development of new low decoding complexity distributed differential space-time codes is considered. The developed codes are designed …
Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh
Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh
Turkish Journal of Electrical Engineering and Computer Sciences
A flexible (2 $\times $ 1) multiple-input, multiple-output (MIMO) antenna with an electromagnetic band gap (EBG) unit cell is designed and measured. The proposed MIMO antenna is based on a circular slotted patch antenna to work at 3.5 GHz. An EBG unit cell is used to reduce the effect of the inherent mutual coupling produced between the closely spaced MIMO elements. The results show that the measured mutual coupling has been reduced by -11.6 dB (from -10 dB to -21.6 dB), and the measured realized gain has been increased by 1.074 dBi (from 1.59 dBi to 2.66 dBi). An improvement …
Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden
Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden
Turkish Journal of Electrical Engineering and Computer Sciences
A new class of scheduling algorithms is proposed for disk drive scheduling. As opposed to choosing the request with the shortest access time in conventional shortest access time first (SATF) algorithms, we choose an ordered sequence of pending I/O requests at the scheduling instant with the shortest cumulative access time. Additionally, we introduce flexibility for forthcoming requests to alter the chosen sequence. Simulation results are provided to validate the effectiveness of the proposed disk scheduler. Throughput gains of 3% and above are shown to be attainable, although this occurs at the expense of increased computational complexity.
Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör
Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör
Turkish Journal of Electrical Engineering and Computer Sciences
Nowadays, smart meters, sensors, and advanced electricity tariff mechanisms such as time-of-use (ToU), critical peak pricing tariff, and real time tariff enable electricity consumption optimization for residential consumers. The main scope of such mechanisms is to promote peak shaving, which leads to minimization of technical losses and avoidance (or delay) of grid onerous investments. This paper proposes a method to determine the optimum capacity of a storage device (SD) that significantly contributes to peak shaving of electricity consumption for residential consumers. Detailed modelling of diverse electric appliances' behavior and consumers' necessities is addressed in order to determine the optimum capacity …
Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani
Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani
Turkish Journal of Electrical Engineering and Computer Sciences
Reactive power optimization (RPO) in a power system is a rudimentary necessity for the reduction of the loss of power. For the requirement of a unity power factor in the RPO system, the reduction of the system losses is ensured. The pivotal requirements of a power system are inclusive of a perfect compensation technique and methodology for stable reactive power compensation. The proposed concept in this paper utilizes the different reactive power optimization algorithms and performs a comparison. The process is accomplished by the use of IEEE 6-bus, 14-bus, and 30-bus systems to test the optimization technique. The conclusive information …
Study Of The Energetic Field Characteristics Of The Te-Modalwaves In Waveguides, Fati̇h Erden
Study Of The Energetic Field Characteristics Of The Te-Modalwaves In Waveguides, Fati̇h Erden
Turkish Journal of Physics
The energetic characteristics of cylindrical medium-free time-domain waveguide fields are solved within the framework of the evolutionary approach to electromagnetics. Solving the boundary-eigenvalue problem for transverse Laplacian yields a configurational basis in the waveguide cross section. Elements of the basis depend on transverse coordinates, whereas the modal amplitudes depend on the longitudinal coordinate, $z,$ and time, $t$. Solving the resulted Klein-Gordon equation yields a basis for analysis of the modal amplitudes. Exact solutions for the amplitudes of TE-modes are obtained, and the energetic field characteristics are derived in accordance with the causality principle.
Determination Of Height Profile From A Two-Dimensional Fringe Signal Using A Two-Dimensional Continuous Wavelet Transform, Özlem Kocahan Yilmaz
Determination Of Height Profile From A Two-Dimensional Fringe Signal Using A Two-Dimensional Continuous Wavelet Transform, Özlem Kocahan Yilmaz
Turkish Journal of Physics
The main objective of this study was 3-dimensional (3D) profile measurements with standard fringe projection, consisting of a CCD and a projector. For obtaining height information of objects pixel by pixel, phases have to be calculated from the images taken by the fringe projection technique. In this study, the 2-dimensional continuous wavelet transform (2D CWT) phase method was used for phase extraction. 1D and 2D CWT analyses of noisy images were compared in simulations performed for a 2-dimensional fringe signal by introducing the carrier frequencies in two spatial directions, $x $ and $y$. Profile measurement of an object was made …
Influence Of Silicon Dioxide Medium On The Structural And Electrical Properties Of Nickel Zinc Ferrite, Jacob George, Abraham Kutticheril Eapen
Influence Of Silicon Dioxide Medium On The Structural And Electrical Properties Of Nickel Zinc Ferrite, Jacob George, Abraham Kutticheril Eapen
Turkish Journal of Physics
Nickel zinc ferrite [(Ni$_{0.65}$Zn$_{0.35}$Fe$_{2}$O$_{4}) _{x}$ / (SiO$_{2}) _{1-x}$ where, x = 1.0, 0.85, 0.65, 0.50, 0.35, and 0.15] is synthesized using the glyoxylate precursor method. The synthesis, characterization, and electrical study of nickel zinc ferrites/SiO$_{2}$ powder with low dielectric constant, very low conductivity, and loss tangent with low frequency dispersion, suitable for good insulators, is reported here. X-ray diffraction, TGA, and FT-IR studies are employed for identifying crystalline phases and structure. Crystallite size is calculated by the Scherrer formula and Williamson--Hall equation and found to fall in the range of 4.9--25 nm. TEM of the samples shows spherical particles of …
Monte Carlo Simulation Of A Medical Linear Accelerator For Filtered And Fff Systems, Çağri Yazğan, Yi̇ği̇t Çeçen
Monte Carlo Simulation Of A Medical Linear Accelerator For Filtered And Fff Systems, Çağri Yazğan, Yi̇ği̇t Çeçen
Turkish Journal of Physics
In order to simulate radiation transport, various algorithms, codes, and programs have been developed. In this study Monte Carlo N-particle code is used to simulate a medical electron linear accelerator gantry for research purposes. Detailed geometry of the LINAC head and water phantom are modeled and simulated for calculations. Analyses are made for filtered and flattening filter-free (FFF) systems. Percent depth dose and dose profile measurements are calculated with Monte Carlo simulations and compared with experimental and theoretical values for quality assurance of the model. Flux, dose, and spectrum analyses are performed for filtered and FFF systems separately. In this …
Applying A Self-Feedback Method To Control Chaos In The Buck Converter, Mei Mei Jia
Applying A Self-Feedback Method To Control Chaos In The Buck Converter, Mei Mei Jia
Turkish Journal of Physics
Chaos exists in the Buck converter due to the switching action of the controlled switch and this nonlinear phenomenon results in unreliable working performances. Hence, this paper uses a self-feedback control method with two adjustable parameters to suppress the chaotic behavior in the Buck converter. First, the self-feedback control method is presented by introducing a generic second-order chaotic system. Then, from the perspective of transfer functions obtained in terms of the piecewise linear model of the controlled Buck converter, effects of controller's parameters on system performances are discussed. On the basis of the Jacobian matrix of the discrete iterative mapping …
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Turkish Journal of Chemistry
For the first time the synthesis of poly($N$-vinyl-2-pyrrolidone)-stabilized cobalt-palladium nanoparticles by an easy method, their characterization, and their use as active catalysts for hydrogen release from hydrolysis of ammonia borane and hydrazine borane is reported here. The catalyst is prepared by simultaneous reduction of suitable cobalt and palladium ions by sodium borohydride in the presence of poly($N$-vinyl-2-pyrrolidone) as a stabilizer. They are characterized by UV-Vis spectroscopy, TEM analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. They provide average turnover frequencies of 30 min$^{-1}$ and 45 min$^{-1}$ in the hydrolysis of ammonia borane and hydrazine borane. They also provide activation energies of …