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Implications Of Mexican Hat-Like Band Structure On Thermoelectric Properties, Muhammad Hilal, Oğuz Gülseren

Turkish Journal of Physics

Electronic band structure of low dimensional materials significantly impacts their thermoelectric performance. A Mexican hat-like band structure, characterized by a ring-shaped extremum in momentum space, offers distinct advantages due to its singularity in the density of states at the band edge and its ability to enhance energy-dependent transport. This work investigates a two-dimensional tight-binding model hamiltonian that incorporates both nearest-neighbor (t1) and next-nearest-neighbor (t2) hopping. The ratio of the hopping amplitudes, ξ = t2/t1, serves as a tunable parameter that modulates the shape and depth of the Mexican hat dispersion. We use an analytical expression for the energy band of …

Optomechanical Dynamics: Exploring Membrane Effects On Cavity Mode Frequencies, Mahmut Can Özuygur

Turkish Journal of Physics

Optomechanics is an emerging research topic that explores the mechanical effects of light. In this paper, we present an analytical study of the mode frequency perturbation in a three-dimensional Fabry Pérot cavity containing a partially transparent membrane. Our analysis reveals that the maximum effect of the membrane occurs when it is placed at an antinode, where the field is at its maximum. The effect is minimized when the membrane is placed at a node, where the field is at a minimum, corroborating earlier one dimensional ”dielectric bump model” calculations. In contrast to previous models, we consider the membrane’s f inite …

Electricity Production From The Temperature Difference Between The Front And Back Surfaces Of A Solar Panel, Bi̇ldane Çamuka, İkram Orak

Turkish Journal of Physics

In this study, the generation of additional electrical energy through the temperature gradient across photovoltaic (PV) panel surfaces was investigated using thermoelectric (Peltier) modules. The experimental setup was conducted in three stages, each focusing on voltage output and thermal behavior under varying configurations. The results showed that Peltier modules can successfully convert thermal differences into electrical energy, and that output voltage increases with greater temperature differentials and active cooling. Among all configurations, the system with a 12 V fan demonstrated the highest voltage generation. This study highlights the potential of integrating thermoelectric elements into PV systems for improved energy efficiency, …

Chelidonium Majus L.-Containing Gel May Improve Diabetic Wound Healing By Modulating Mmp-2, Mmp-9, And Collagen Levels, Kaan Kaltalioğlu, Eli̇f Naz Gürsoy, Barbaros Balabanli, Zeki̇ Aytaç, Şule Coşkun Cevher

Turkish Journal of Biology

Background/aim: Delayed wound healing in diabetic patients is a significant complication that reduces quality of life, prompting the continuous investigation of new therapeutic agents. This study designed to explore the dose-dependent effects of different parts of Chelidonium majus L. (CM), a medicinal plant traditionally used for skin disorders, on diabetic skin wounds.

Materials and methods: In diabetic rats, full-thickness excisional wounds were formed. CM-containing gels (aerial parts at 3%, 6%, 9% and root at 0.5%, 1%, 1.5%) were developed and applied to the wounds. After the treatment period, the rats were sacrificed, and wound healing activity was assessed macroscopically, histopathologically, …

Optimization And Model Averaging Of Histogram-Based Place Cell Firing Rate Maps Using The Point Process Framework, Murat Okatan

Turkish Journal of Electrical Engineering and Computer Sciences

The firing rate of hippocampal place cells depends on the spatial position of the organism in an environment. This position dependence is often quantified by constructing spike-in-location and time-in-location histograms, the ratio of which yields a firing rate map. The purpose of this study is to present a new method for optimizing the spatial resolution of histogram-based firing rate maps. It is pointed out that histogram-based firing rate maps are conditional intensity functions of inhomogeneous Poisson process models of neural spike trains, and, as such, they can be optimized through model selection within the point process framework. The point process …

Isar Imaging Of Drone Swarms At 77 Ghz, Remzi̇ye Büşra Çoruk, Ali̇ Kara, Eli̇f Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

The proliferation of easily available, internet-purchased drones, coupled with the emergence of coordinated drone swarms, poses a significant security threat for airspace. Detecting these swarms is crucial to prevent potential accidents, criminal misuse, and airspace disruptions. This paper proposes a novel inverse synthetic aperture radar (ISAR) imaging technique for high-resolution reconstruction of drone swarms at 77 GHz millimeter wave (mmWave) frequency, offering a valuable tool for military and defense anti-drone systems. The key parameters affecting down-range and cross-range resolution (0.05 m), ultimately enabling the generation of detailed ISAR images are discussed. Here, we create diverse scenarios encompassing various swarm formations, …

Adaptive Backstepping Control With Real-Time Fuzzy Logic Parameter Selection Of A Field- Oriented Control-Based Permanent Magnet Synchronous Motor Driver, Fati̇h Bayir, Erkan Zergeroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes an adaptive backstepping control approach integrated with a real-time fuzzy logic parameter selection algorithm to enhance the robustness and stability of a permanent magnet synchronous motor (PMSM) controller under parametric uncertainties and external disturbances. Although backstepping control performs well under varying disturbances, it must be supported by an adaptive control algorithm to effectively handle both variable disturbances and parameter uncertainties. Moreover, because the fixed parameters of the adaptive backstepping controller limit the dynamic performance of the velocity tracking loop, this study incorporates fuzzy logic control—a soft computing algorithm capable of real-time parameter adjustment—to achieve more robust outcomes. …

Excitation Of Synchronous Machine By Contactless Power Transfer - Review From The Perspective Of Electric Vehicles, Erhan Tuncel, Emi̇n Yildiriz

Turkish Journal of Electrical Engineering and Computer Sciences

Electrically excited synchronous machines (EESMs) are one of the best choices for propulsion motor appli cation in electric vehicles (EVs) due to their wide torque-speed characteristics. Moreover, the air gap flux density can be easily controlled by varying the excitation current. Despite these advantages, it is difficult to transfer the current required by the rotating excitation winding into the motor under conventional methods, so it is not widely used in EVs. In this study, the emerging literature on contactless power transfer methods is reviewed for applicability to an EESM that can operate as an EV propulsion motor. Design criteria such …

Rescon: Residual Consistency For Real-World Super-Resolution, Erdi̇ Saritaş, Hazim Kemal Ekenel

Turkish Journal of Electrical Engineering and Computer Sciences

Real-world super-resolution is a highly challenging problem in the field of computer vision. Besides enhancing image resolution and improving visual details, information loss due to complex real-world degradations is desired to be restored. One of the primary hardness of this problem is finding sufficiently large paired datasets for training. Researchers have developed techniques that generate synthetic low-resolution pairs using high-resolution images with a generative adversarial network-based degradation generator to address this issue. In these approaches, the degradation generator is trained by utilizing real-world low-resolution images as the target domain, generating a degraded low-resolution counterpart of the high-resolution input. However, in …

Magnetic Macro Pendulum Design And Real-Time Control Application: Simulation And Experiment, Hüseyi̇n Yildiz, Serdar Yilmaz, Yasemi̇n Poyraz Koçak, Erol Uzal

Turkish Journal of Electrical Engineering and Computer Sciences

Over the last decade, the number of studies in the field of magnetic micro robots has significantly increased due to expectations of performing microsurgery, drug delivery, and similar medical procedures. Magnetic micro robots have advantages over other types of micro robots in terms of having independent designs for rotor and stator structures. Magnetic micro robots can be controlled by magnetic fields and can be programmed to move in certain directions and to perform various functions. This paper implements the computer-aided real-time control of a single-arm micro-pendulum structure to (eventually) perform cell manipulation tasks. The mechanical structure, mathematical model, control circuit …

Some Properties Of Rescaled Sasaki Type Metric On The Coframe Bundle, Habil Fattayev, Arif Salimov

Turkish Journal of Mathematics

In this paper we introduce the rescaled Sasaki type metric on the coframe bundle of a Riemannian manifold and investigate the Levi-Civita connection, curvature tensor, paracomplex structures of coframe bundle with this metric

Janowski Close-To-Convexity Harmonic Mappings, Bushra Arif, Jacek Dziok, Wasim Ul Haq, Mohsan Raza

Turkish Journal of Mathematics

In the present work we introduce harmonic univalent functions related to Janowski close-to-convexity and we provide their necessary and sufficient criteria. The extreme points and topological features of such harmonic mappings will also be investigated. By applying extreme points theory, we obtain integral mean inequalities, distortion theorems, and coefficient estimates for families of harmonic functions.

Approximate Controllability Of Fractional Backward Stochastic Differential Inclusions With Order 1/2 < P < 1, Müberaa Selah

Turkish Journal of Mathematics

In this paper, fractional backward stochastic differential equations are extended to multivalued forms. Since the problem of approximate controllability of the obtained fractional backward stochastic differential inclusions has not yet been addressed in the literature, we focus on the approximate controllability of these systems. The study’s main results, such as existence of the mild solution and approximate controllability for fractional backward stochastic differential inclusions, have been proven through fractional calculus, Bohnenblust-Karlin Theorem, and appropriate conditions.

The Circular Sum Of Points Of An Affine Segment, Mircea Crasmareanu, Marius Munteanu

Turkish Journal of Mathematics

This note introduces a sum for two interior points of an affine segment [AB] based on a trigonometric approach. Some properties of this operation, along with general examples (including squares of endpoints, the midpoint, and the centroid), are discussed. A main result is that the midpoint of a segment is the circular sum of the points dividing the segment with the ratios 4 and 9. In addition, we completely solve a Diophantine equation associated with the circular sum in order to identify all points with integer ratio whose circular sum is a point with integer ratio.

Weighted Inequalities For Discrete Bilinear Hardy-Type Operator With A Matrix, Nazerke Zhangabergenova, Ainur Temirkhanova

Turkish Journal of Mathematics

In this paper, we consider a new discrete bilinear inequality of Hardy-type involving a matrix operator. We establish weight characterizations of this inequality under some conditions on the matrix entries.

New Characterizations Of Weights In Dynamic Inequalities Of Hardy's Type On Time Scales, Mario Krnic, Mahmoud M. Osman, Samir H. Saker

Turkish Journal of Mathematics

The main aim of this paper is to establish some new characterizations of the weights in Hardy-type dynamic inequality, dual Hardy-type inequality, andreverse Hardy-type dynamic inequality on time scales. Some integral and discrete inequalities due to Copson, Leindler, and Hyun and Kim will bededuced as special cases. Moreover, new dynamic inequalities via convexity are proved.

Analytical Solution And Stability Of Ψ-Prabhakar Delayed Systems: Application To Antibiotic Production, Mustafa Aydin

Turkish Journal of Mathematics

The analytical solution of the linear ψ -Prabhakar delay differential equations is explored using the method of variation of parameters, in which a ψ -general delayed exponential matrix function is introduced. The ψ -Prabhakar calculus is enhanced in terms of the semi-group property, inversion results, and several simplified calculations and relations. The system's stability is analyzed within the framework of Ulam-Hyers stability. Finally, the theoretical findings are validated through an application to antibiotic production.

Integral Extensions On Growth And Higher Derivatives Of A Polynomial, Nirmal Kumar Singha, Fahreddi̇n G. Abdullayev, Barchad Chanam

Turkish Journal of Mathematics

A well-known theorem due to Ankeny and Rivlin states that if p(z) is a polynomial of degree n such that p(z) has no zero in |z| < 1, then
max_|z|=R≥1 |p(z)| ≤ (R^{n + 1} / 2) max_|z|=1 |p(z)|.
This research examines the polynomial p(z), ensuring that it has no zero in the disk |z| < k, where k ≥ 1. At the same time, we investigate the s^th derivative of this polynomial, where 0 ≤ s < n. In our effort to establish integral formulations of the inequalities related to the derivatives of this class of polynomials, we have successfully extended and generalized Ankeny and Rivlin’s inequality to integral settings. Additionally, part of our findings provides integral analogs of results by Mir [J. Anal., 27 (2019), 851−857]. Moreover, another aspect of our work leads to an improvement in the result of Jain [Turk. J. Math., 31 (2007), 89−94], which we have also verified using an example. We have also compared our results with a previously known result using this numerical example, where the bounds that are in terms of integral means are estimated numerically by numerical integration using Simpson’s 1/3^rd rule and illustrate graphically the obtained inequalities as regards sharpness.

On The Solutions Of Difference Equations Of The Volterra Type, Hakan Adigüzel

Turkish Journal of Mathematics

In this paper, we conduct a thorough analysis of the qualitative behavior of solutions to three different types of difference equations of the Volterra type. Utilizing the principles of discrete calculus and various well-known inequalities, we have presented our findings. To conclude our theoretical findings, we provide several examples that illustrate full alignment with the findings.

Morphotectonic And Active Tectonic Properties Of The Yenicekent Travertines With Chibanian–Meghalayan Ages In The Denizli Graben (Türkiye), Ömer Eki̇zoğlu, B. Levent Mesci̇

Turkish Journal of Earth Sciences

Travertine deposits that crop out in the Yenicekent travertine field within the Denizli graben in western Türkiye are described and illustrated. Three morphologies of travertine are identified in this field, comprising fissure-ridge type, range-front, and eroded-sheet type, with each type resulting from deposition by geothermal waters driven by ongoing tectonism. The fissures in the Yenicekent travertine field extend parallel to active normal faults bounding the Denizli basin from the NE-directed Tripolis and Pamukkale faults, and were formed by waters released under tensile stress in the footwall blocks of normal faults. This study aimed to link the chronological development of travertine …

U-Pb Calcite Geochronology, Epr, Geochemistry, And C-O-Sr Isotopes Of Ancient Marbles In The İznik Region (Bursa-Türkiye), Namik Aysal, Özge Karslioğlu, Emre Erdem, Marcel Guillong, Si̇nan Öngen, İbrahi̇m Tonguç Uysal, Ersi̇n Kaygisiz, İpek Deni̇z Yildirim

Turkish Journal of Earth Sciences

The İznik city (ancient Nicaea), located east of Lake İznik (known as -“Bithynia” in ancient times), has been an important political and cultural centre of Asia Minor since the Hellenistic period. Marbles produced in the quarries in the vicinity (Ömerli and İnikli villages, Deliktaş-Sarıtaş hills) were used both in the construction of the walls and in many ancient works in the city. Approximately eighteen ancient marble quarries producing grey and white marbles were investigated in the region. Petrography, EPR, XRD, C-O-Sr isotope and whole rock geochemistry analyses were performed for characterization of the samples collected from the quarries for the …

Tectonic Setting Analysis Of The Early Tortonian Lacustrine Basins In Nw Iran Based On Sedimentological, Paleontological, And Structural Studies, Enayat Haghfarshi, Seyyed Reza Moussavi̇ Harami̇, Mohammad Faridi, Peyman Rezaee

Turkish Journal of Earth Sciences

The Lignite Beds of Tabriz are among the Neogene formations in the northwest region of Iran that were formed as individual basins in the margin of the Tabriz fault and the suburbs of Tabriz City during the Late Miocene. These beds have many similarities in terms of facies and lithology. In this study, two stratigraphic sections of the main Lignite Beds unit, with a total thickness of 203 m, were measured and sampled. Fine- and medium-grained siliciclastics, limestones, lignite, tuff, and calcrete sedimentary facies were identified. The new fossils identified in this study include gastropods (Borysthenia naticina, Hydrobia sp., Lymnaea …

Editorial Note To The Article “Tectonic Geomorphology Of The South-Eastern Section Of The Burdur-Fethiye Shear Zone, Western Taurides: Morphotectonic Framework Of The Eşen Basin” [Turkish Journal Of Earth Sciences 33 (5) 2024 503-529 ], Orhan Tatar

Turkish Journal of Earth Sciences

As part of the journal’s commitment to open scientific dialogue, we are publishing a Letter to the Editor regarding the article “Tectonic geomorphology of the south-eastern section of the Burdur-Fethiye Shear Zone, Western Taurides: morphotectonic framework of the Eşen Basin” along with a reply from the authors, who have provided a clarification in response to the concerns raised. We consider such exchanges to be a normal and healthy part of the scientific process, and we are presenting both perspectives to allow readers to form their own conclusions.The views expressed in the letter and the reply are those of the respective …

A Model Study On Enhancing The Horizontal Gradient Of Potential Fields With The Vertical Derivative, Luan Thanh Pham, Saulo P. Oliveira, Erdi̇nç Öksüm, Jeferson De Souza

Turkish Journal of Earth Sciences

The total horizontal gradient (THG) and its derivatives are commonly used in interpreting potential fields. Because THG is a nonharmonic function, its vertical derivative (VD) can be consistently computed using, e.g., a finite-difference approximation. The calculation of VD in the wavenumber domain is physically meaningful for harmonic functions, but it provides a pseudovertical derivative (PVD) when applied to nonharmonic fields that can be used in some edge detectors, such as THG. Through experiments with synthetic and field datasets, we evaluated the performance of the PVD of THG in the tilt angle of THG (TAHG) and fast sigmoid-based edge detector (FSED). …

On Reference Accuracy: Clarification Of The Original Data, İrem Eli̇tez, Cenk Yaltirak

Turkish Journal of Earth Sciences

Although it is claimed that the same data was correctly attributed to Alçiçek (2007) in Elitez and Yaltırak (2023), no age data from Alçiçek (2007) were actually used in that study. In fact, the stratigraphic interpretation proposed by Alçiçek (2007) exhibits notable discrepancies with the conclusions presented by Elitez and Yaltırak (2023). Alçiçek (2007) defines the geological units overlying the basement as the Eşen Formation (comprising the Çetilidüz, Çaykenarı, and Kocaçay members) and Quaternary units. Based on the fossil Palaeotragus rouenii, the author suggests that the Neogene succession begins with Late Miocene alluvial-fan conglomerates, sandstones, and mudstones, whereas lacustrine sedimentation …

Citing The Citer: A Way To Claim Original Data, Mehmet Ci̇hat Alçi̇çek

Turkish Journal of Earth Sciences

In Elitez and Yaltırak (2024, p. 3), the “Upper Miocene” age data for the Eşen Basin fill is cited from Elitez and Yaltırak (2023). However, in that work, the same data was correctly attributed to Alçiçek (2007), which is the original source. Citing a secondary source instead of the original one is avoided in scientific writing. This letter aims to correct this citation practice.

The First Documented Case Of Melanism In Sciurus Anomalus, Recorded In Türkiye, Burak Akdağ, Balkan Mega

Turkish Journal of Zoology

This study reports the first documented case of melanism in the Caucasian squirrel (Sciurus anomalus) from Türkiye. While melanism has been documented in 12 other species within the Sciurus genus, it has not previously been recorded in S. anomalus. The observation was made during a herpetological field survey in Erzincan Province, Türkiye, where a melanistic specimen was photographed in a mixed habitat comprising natural vegetation and cultivated land. In mammals, melanism is widely regarded as an adaptive trait, potentially conferring advantages such as improved thermoregulation in colder climates and enhanced crypsis in shaded forest environments. This novel observation not only …

Insights Into Therapeutic Discovery Through The Kelch Domain Structure Of Keap1 At Ambient Temperature, Merve Yilmaz, Belgi̇n Sever, Yi̇ği̇t Kutlu, Mehmet Gül, Ceren Okuducu, Serra Tavli, Masami Otsuka, Mikako Fujita, Turkan Hali̇loğlu, Hali̇li̇brahi̇m Çi̇ftçi̇, Hasan Demi̇rci̇

Turkish Journal of Biology

Background/aim: The Kelch-like-ECH associated protein 1 (Keap1) is an integral component of the E3-ubiquitin ligase complex, which binds to Nuclear factor erythroid 2-related factor 2 (Nrf2) and facilitates its degradation by the 26S proteasome. The Kelch domain of Keap1, composed of six repeated structural motifs, plays a key role in this interaction. This study aims to investigate the dimeric structure of the Keap1 Kelch domain at ambient temperature and to examine its implications for conformational dynamics, particularly in relation to the DMF and Nrf2 binding sites.Materials and methods: The dimeric crystal structure of the Keap1 Kelch domain was determined at …

Discovery And Characterization Of Selective Lipase-Inhibiting Polyheterocyclic Derivatives: A Combined In Silico And In Vitro Study, Madjda Benguechoua, Mebarka Imane Benguechoua, Khedidja Benarous, Houssem Boulebd, Ibtissem Kadi, Ari̇f Mermer, Yakup Şi̇ri̇n, Alaeddine Kaouka, Mohamed Yousfi

Turkish Journal of Biology

Background/aim: Obesity has become a global health crisis with an increasing prevalence, necessitating the search for effective therapies. Schiff base derivatives, known for their broad pharmacological activities, have gained attention as potential antiobesity agents. This study aimed to investigate the lipase inhibitory potential of novel Schiff base derivatives and assess their drug-like properties through in vitro assays and in silico methods. Materials and methods: The lipase inhibitory activity of synthesized Schiff base derivatives was evaluated using in vitro assays, with IC50 values determined for each compound. Additionally, in silico ADMET predictions (absorption, distribution, metabolism, excretion, and toxicity), molecular docking studies, …

The Effects Of Hsa-Mir-26a-5p On Cell Proliferation, Migration, And Pi3k Inhibitor Sensitivity In Metformin-Resistant Triple Negative Breast Cancer Cells, Şahi̇ka Cingir Köker, Senem Noyan, Banu Yalçin, İrem Doğan Turaçli

Turkish Journal of Biology

Background/aim: Metformin is commonly used to manage type 2 diabetes (T2D) and is being investigated for its potential antiproliferative effects in cancer, particularly in patients with both T2D and malignancies. Drug resistance can develop with any therapeutic agent, and metformin is no exception. As we showed in our previous study, metformin-resistant MDA-MB-468 (MET-R) cells exhibited an EMT-like phenotype. Many transcription factors, as well as miRNAs, can contribute to this altered phenotype. Our current study identifies the contribution of hsa-miR-26a-5p expression to the previously observed phenotype. Materials and methods: By utilizing bioinformatic tools, we identified hsa-miR-26a-5p, whose expression was significantly altered …