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Hyers-Ulam And Hyers-Ulam Rassias Stability Of Caputo Fractional Hahn Difference Equations, Karima Mohamed Oraby, Alaa E. Hamza, Afrah Al-Bossly

Turkish Journal of Mathematics

​In this paper, we investigate Hyers–Ulam and Hyers–Ulam–Rassias stability for fractional linear Hahn difference equations of Caputo Type. To the best of our knowledge, this is the first work concerning Hyers–Ulam type stability in the framework of Caputo fractional Hahn difference equations, thereby filling a significant gap in the literature on fractional stability theory. Our approach is based on establishing an equivalence between the fractional Hahn difference initial value problem and a corresponding fractional integral equation, via the Caputo–Hahn inversion formula. These results lay a strong groundwork for analyzing the stability of Hahn fractional systems, which could be useful in …

Stochastic Control Of Inventory And Scheduling Decisions In An Open Network Of Repairables, Erhun Özkan

Turkish Journal of Mathematics

We study maintenance operations for capital goods with repairable components. Because the downtime of a capital good is costly, the maintenance provider keeps an inventory of spare parts to quickly replace broken parts of the capital goods. After the replacement, the broken part is added to the repair facility’s repair queue. Upon a part breakdown, if there is no spare part in the inventory, then the maintenance provider has two options: (i) it can backorder the spare part demand, (ii) it can execute an emergency repair, which is done immediately and quickly, and is followed by a quick installation of …

A Full-Scale Watertight Workflow Numerical Study For A Triangular Fin And Tube Heat Exchanger, Hamdi̇ Selçuk Çeli̇k, Bahadir Doğan, Lati̇fe Berri̇n Erbay

Turkish Journal of Mathematics

In this study, the thermo-hydraulic characteristics of an air-cooled triangular finned tube heat exchanger were analyzed numerically. The full-scale heat exchanger was modeled using Ansys Fluent watertight workflow, considering water as the primer fluid to precisely investigate the effects of geometrical factors. The effects of fin height, fin width, and fin spacing of the triangular fins on the performance of the heat exchanger were examined using k-ω turbulence model. A basic finned-tube heat exchanger model, which was manufactured as a monolithic structure without tube-fin contact resistance by milling from aluminum 5083 material, was tested in an air tunnel to verify …

Acetylcholinesterase Immobilization On A Natural Thin Membrane For Stable Biocatalyst Design, Si̇nem Öztürk, Ceyhun Işik, Mustafa Teke

Turkish Journal of Chemistry

This study involved the immobilization of acetylcholinesterase (AChE) onto a natural thin membrane extracted from the inner epidermal layer of Allium cepa, with the aim of enhancing the enzyme’s stability, activity, and reusability for potential biotechnological applications. The membrane, composed of biocompatible polymers and naturally occurring functional groups, was used as a sustainable support in a combined strategy involving adsorption followed by glutaraldehyde-mediated cross-linking. Immobilization conditions were optimized by evaluating key factors such as enzyme concentration, membrane quantity, cross-linker dosage, and contact time to achieve maximal catalytic efficiency. Structural and morphological changes on the membrane surface were assessed via scanning …

Folic Acid-Targeted Polymeric Complex Imprinted With Doxorubicin And Quercetin For Controlled Drug Delivery In Cancer Therapy, Ceren Türkcan, Emi̇rhan İşeri̇

Turkish Journal of Chemistry

​Cancer therapy is often limited by the systemic toxicity and dose-dependent adverse effects of conventional chemotherapeutic agents such as doxorubicin (DOX). In this study, a folic acid-functionalized molecularly imprinted polymeric complex based on poly(HEMA) crosslinked with ethylene glycol dimethacrylate was synthesized for the controlled release of DOX in combination with quercetin (QUE), a flavonoid known for its antioxidant and chemosensitizing properties. The aim of this work was to develop and physicochemically characterize a preliminary targeted drug delivery platform at a material-design level. The polymeric complex was synthesized via free-radical polymerization following a DOX–QUE precomplex formation step. Structural characterization was performed …

Antifungal Activity Of Isolated Compounds From Centaurea Salicifolia Var. Salicifolia Against Candida Species, Including Multidrug-Resistant C. Auris, C. Inconspicua, And C. Dubliniensis, Seli̇n Tufan, Di̇lek Şatana, Nur Tan

Turkish Journal of Chemistry

Natural compounds obtained from plants have always held great potential for drug discovery and, as such, have drawn the attention of researchers as novel antifungal molecules that can be effective against fungal resistance. The antifungal activity of sesquiterpene lactones has been extensively investigated against various fungal strains, but there is limited data on their antifungal activity against Candida species. Sesquiterpene lactones are abundant in the Asteraceae family, and 90% of identified sesquiterpene lactones have been isolated from members of this family. Three extracts obtained from the aerial parts of Centaurea salicifolia var. salicifolia, which had not been investigated prior to …

Electrochemical Determination Of Terbutaline Using A Sno2 Nanoparticle-Modified Carbon Paste Electrode, Rauf Gulamov, Şenol Alpat, Si̇bel Kilinç Alpat

Turkish Journal of Chemistry

Terbutaline hemisulfate (THS), a selective beta-2 agonist, is preferred as a bronchodilator for the treatment of asthma and bronchitis, as well as a tocolytic agent to delay labor in acute situations during premature birth. The use of beta-2 agonists above a certain dose is considered doping in sports competitions. Therefore, it is important that they be determined with high sensitivity and selectivity within a short analysis time. In this study, a SnO2 nanoparticle-modified carbon paste electrode was developed for the determination of THS. Cyclic voltammetry and differential pulse voltammetry were employed as electrochemical methods. The operating conditions of the developed …

Sensitive Electrochemical Sensor For Simultaneous Determination Of Epinephrine And Norepinephrine By Sio2np@Mwcnt-Cooh Nanoparticle-Modified Spces​, Merve Yilmaz Çilçar, Meli̇ke Bi̇lgi̇ Kamaç, Ayşenur Yilmaz Kabaca, Şahi̇n Toparli, Faruk Terzi̇oğlu, Emi̇r Ateş

Turkish Journal of Chemistry

Epinephrine (EP) and norepinephrine (NEP), both neurotransmitters, are two important biomolecules that play critical roles in the body, from the central nervous system to metabolic processes. They are also important biomarkers for clinical diagnosis and monitoring. In this study, a novel, fast, practical, and high-performance electrochemical sensor based on a SiO2NP@MWCNT-COOH nanocomposite was developed for the simultaneous determination of EP and NEP. The nanocomposite was modified onto the surface of screen-printed electrodes (SPCEs) and its characterization was performed (SEM-EDX, XRD, FTIR, CV, DPV, and EIS). The individual and simultaneous determinations of EP and NEP were performed using square-wave voltammetry, yielding …

Chitosan Microparticle-Based Antibacterial Nasal Barrier Formulation And In Vivo Evaluations, Güli̇z Ak, Ayça Erek, Tuğba Karakayali, Şadi̇ye Çeti̇n, Şenay Şanlier

Turkish Journal of Chemistry

Microorganisms remain a major cause of infectious diseases, emphasizing the need for alternative and complementary antimicrobial strategies. In this context, plant-derived materials have attracted increasing attention for their antimicrobial and protective properties. Chitosan, a biocompatible and cationic biopolymer, has emerged as an effective carrier system for encapsulating such plant-derived components. In this study, chitosan microparticles were prepared through ionic gelation followed by spray drying and loaded with thyme oil and olive leaf extract. The resulting microparticles exhibited an average size of approximately 1.8 μm and a total phenolic content of 23 mg GAE/g. These microparticles were incorporated into a glycerin–starch …

A Poly-L-Lysine-Functionalized Electrochemical Immunosensor Enables Highly Sensitive Detection Of Tumor Necrosis Factor Receptor-Associated Protein 1, Berfi̇n Vural, Mustafa Kemal Sezgi̇ntürk

Turkish Journal of Chemistry

Tumor necrosis factor receptor-associated protein 1 (TRAP-1), a member of the mitochondrial heat shock protein family (HSP90), is essential for protein homeostasis, stress response, and cell cycle. TRAP-1 not only optimizes cellular energy production but also prevents cell death, thereby supporting the survival and proliferation of tumor cells. In addition to cancer, TRAP-1 has been associated with Parkinson’s disease, certain autoimmune disorders, and abnormalities in the kidney and urinary tract. In this study, a unique and useful indium tin oxide-polyethylene terephthalate (ITO–PET)-based electrochemical biosensor is described for detecting the biomarker TRAP-1. The ITO–PET electrode, selected as the working electrode, is …

Aptamer–Gold Nanoparticle-Based Lab-In-A-Tube Colorimetric Detection Of Malathion: Evaluation With Classical And Digital Readout Techniques, Emi̇ne Güler Çeli̇k

Turkish Journal of Chemistry

Colorimetric biosensing devices represent an important class of point-of-care (POC) diagnostics due to their ability to provide visible test outputs, their ease of integration with smartphone-based sensing, and their portability for field testing. In the context of agrifood safety, there is a growing need for portable, robust, and cost-effective detection devices. Pesticide residues can be present in a wide range of environmental and food samples, from water resources to fruits and vegetables, resulting in an increasing global demand for on-site testing. Colorimetric assays, when combined with smartphone-based sensing, can effectively address these needs. In this work, the aggregation-induced color change …

A Comparative Analysis Of Clinical Quality And Readability Of Neuropathic Pain Patient Information Leaflets: Türkiye Versus The United States, Gonul Sari, Argun Pire

Turkish Journal of Medical Sciences

Background/aim: Neuropathic pain management requires high patient adherence and complex dose-titration regimens, making the readability of patient information leaflets (PILs) a critical patient safety factor. This study aimed to compare the clinical content quality and linguistic readability of PILs for neuropathic pain medications between Türkiye (TİTCK) and the United States (DailyMed).

Materials and methods: A total of 11 pairs of innovator medications were analyzed. Clinical content was assessed using the 15-item Keystone Clinical Content Checklist (KCCC). Readability was assessed using the Ateşman index for Turkish texts and the Flesch Reading Ease Score (FRES) for English texts. Information quality and reliability …

Beyond Individual Willingness: Family Veto, Legal Knowledge, And The Dynamics Of Organ Donation In Türkiye ​, Hasan Gi̇ray Ankara, Hakan Değerli̇, Semi̇h Baş

Turkish Journal of Medical Sciences

Background/aim: The aim was to understand the factors underlying the dynamics of organ donation behavior by focusing on three different aspects. Three models were tested in this regard, namely (i) individual willingness for the donation of one’s own organs, (ii) willingness to approve organ donation for close relatives, and (iii) a family veto gap.

Materials and methods: A national-level adult sample from the Eurobarometer 72.3 survey (collected in 2009) conducted in Türkiye was utilized. Standard and penalized logistic regression models were employed to conduct the analyses.

Results: The results show that discussing organ donation with family members and being aware …

Robust Soil Moisture Content Detection Based On Data Augmentation Under Different Testing Conditions, Yang Li, Chenghao Liu, Jing Nie, Jingbin Li

Turkish Journal of Agriculture and Forestry

Accurate and cost-effective monitoring of soil moisture content is essential for the development of precision agriculture and the optimization of water resource management. While low-frequency acoustic signals are used to detect soil moisture content, models trained with controlled laboratory acoustic data often exhibit significant performance degradation with field data due to their sensitivity to environmental noise, soil heterogeneity, and structural variations. This study proposes a novel framework to enhance model robustness and generalization by integrating a WGAN-GP network data augmentation strategy into the soil moisture content workflow. This framework is designed to generate high-quality and diverse data on different soil …

Genetic Diversity And Population Structure Of Carob Germplasm From Lebanon, Morocco, And Spain Reveal Potential For Innovative Breeding Programs, Mohamad Ali El Chami, Guillermo Palacios-Rodriguez, Rafael Maria Navarro-Cerrillo, Lamis Chalak, Maria Dolores-Rey

Turkish Journal of Agriculture and Forestry

The carob tree (Ceratonia siliqua L.) is a drought-tolerant species native to the Mediterranean Basin. It has been cultivated for centuries for its highly nutritious, edible pods. Genetic diversity is one of the key requirements for the effective management and utilization of plant genetic resources. In this study, we evaluated the genetic diversity and population structure of 169 seminatural carob individuals from Lebanon, Spain, and Morocco using nine expressed sequence tag-simple sequence repeat (EST-SSR) markers. A total of eight polymorphic EST-SSR loci produced 43 alleles, with Cesi_187 and Cesi_1187 identified as the most informative markers. Results of AMOVA and SAMOVA …

Trace Elements In Complete Feeds Used In Intensive Rearing Of Cattle, Poultry, And Pigs: Occurrence And Predicted Transferred Concentrations In Animal-Derived Food, Elizabeta Dimitrieska Stojkovikj, Vangelica Enimiteva, Aleksandra Angjeleska, Risto Uzunov

Turkish Journal of Veterinary & Animal Sciences

This study investigated the concentrations of essential (Zn, Cu, Mn, Co, and Mo) and toxic (Pb, Cd, As, and Hg) trace elements in complete feeds used for the intensive rearing of cattle, poultry, and pigs in North Macedonia and predicted their transfer into animal-derived foods. A total of 107 feed samples were collected from 40 farms between May 2023 and April 2024 and analyzed using inductively coupled plasma mass spectrometry. The results revealed that while most essential elements were within the regulatory limits, Co exceeded the maximum level in two cattle feed samples. Zn, Cu, and Mn levels were generally …

The Effect Of Spin Polarization On Ion-Acoustic Solitary Waves In Quantum Plasmas, Amirhosein Rezvani, Sedigheh Miraboutalebi, Leila Rajaei, Mahmoodreza Sharifian

Turkish Journal of Physics

The exchange interaction, a fundamentally quantum-mechanical phenomenon, can significantly modify the classical description of cold, overdense plasmas. These quantum effects can be systematically analyzed within the framework of quantum magnetohydrodynamic (QMHD) theory, which enables the use of separate momentum equations for spin-up and spin-down electron populations. In this study, we adopt this approach to incorporate exchange interactions for both spin species and investigate the excitation of ion-acoustic wave (IAW) solitons in the plasma system. Using a perturbative expansion method, the governing equations are reduced to a nonlinear Schrödinger equation (NLSE), which admits solitonic wave solutions. The stability of these solitons …

On Cosmological Equation Of State From The First Law Of Thermodynamics, Ch'ng Han Siong

Turkish Journal of Physics

We derive several equations of state for different types of energy from the first law of thermodynamics. We derive the equation of state of a Machian universe from the well-known energy formulaE=mc2. This equation of state is consistent with previously reported results. We then propose hypothetical forms of energy that lead to the equations of state of the Chaplygin gas, generalized Chaplygin gas, and modified Chaplygin gas. We also obtain the energy density of the Chaplygin gas by dividing the hypothetical energy by the volume of the universe, and find that it is consistent with previously reported results. Finally, we …

Design And Fabrication Of Petri Dish Optimized For High-Frequency Acoustic Microscopy Using 3d Printing, Tuna Pesen, Beyza Ceren Eren, Arda İnanç, Bora Akgün

Turkish Journal of Physics

High-frequency imaging in acoustic microscopy requires the use of Petri dishes with thin and acoustically transparent bottoms to minimize signal attenuation and distortion. Commercially available options suitable for this purpose are often expensive or limited in compatibility with custom setups. Here, we present a cost-effective and easily customizable alternative developed in our laboratory, consisting of a 3D-printed frame combined with commercially available stretch film. The stretch film serves as an ultrathin (8 µm thickness) base that supports efficient high-frequency acoustic transmission, enabling clear and reliable imaging. Beyond acoustic microscopy, the adaptable design is also compatible with other modalities such as …

Cover And Contents

Turkish Journal of Physics

No abstract provided.

Toroidal Plasmonic Nanodimers For Enhanced Near-Infrared Emission In Heterostructured Inp Quantum Dots, Arda Gülücü, Emre Ozan Polat

Turkish Journal of Physics

Near-infrared (NIR) emitters operating in the 650--900 nm spectral range are highly attractive for imaging and sensing in turbid media. However, cadmium-free InP-based quantum dots (QDs) often exhibit limited brightness owing to nonradiative recombination pathways and inefficient photon outcoupling. In particular, heterostructured InP QDs may possess band alignments that induce partial spatial separation of charge carriers, thereby reducing the electron-hole wavefunction overlap. This characteristic modifies the intrinsic recombination dynamics and increases the sensitivity of their emission to the surrounding photonic environment. Here, we investigate silver toroidal plasmonic nanoantenna dimers (Ag TPNDs) using finite-difference time-domain (FDTD) simulations as a geometry-tunable platform …

Radiation Pressure And Membrane Dynamics In Cavity Optomechanics: Interaction Hamiltonian And Quantization, Mahmut Can Özuygur

Turkish Journal of Physics

Cavity optomechanics explores the interaction between light confined in optical cavities and mechanical oscillators, primarily driven by radiation pressure forces. These interactions enable significant advances in precision measurements, quantum information processing, and tests of fundamental quantum mechanics. This paper presents a detailed analysis of membrane vibration and radiation pressure force within a cavity optomechanical system. The membrane's equation of motion is derived, the radiation pressure force is evaluated within the Lorentz force formalism, and the corresponding interaction Hamiltonian is formulated. Quantization of the resulting Hamiltonian enables the investigation of quantum phenomena, including entanglement generation and quantum state transfer, and provides …

Observational Constraints On The Structure-Induced Dark Energy Model, Ali̇ Kazim Çamlibel

Turkish Journal of Physics

A new phenomenological dark energy model, originally associated with large-scale structure formation and proposed as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the framework of General Relativity in a Friedmann-Robertson-Walker spacetime and its model parameters were estimated using cosmic chronometers and recent DESI data. It turns out that the proposed model can serve as an alternative evolving dark energy model with a novel equation of state function. Given the form of this phenomenological energy density ansatz, which rises with the nonlinear structure growth in the universe and declines as cosmic voids …

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.

Generalized Splines Over ℤ-Modules On Arbitrary Graphs, Gökçen Di̇laver, Selma Altinok

Turkish Journal of Mathematics

Let [[EQUATION]] be a commutative ring with identity and [[EQUATION]] a graph.  Fix an [[EQUATION]]-module [[EQUATION]] for each vertex [[EQUATION]] of [[EQUATION]], an extending generalized spline on [[EQUATION]] is a vertex labeling [[EQUATION]], where for each edge [[EQUATION]] there exists an [[EQUATION]]-module [[EQUATION]] together with homomorphisms [[EQUATION]] and  [[EQUATION]] such that [[EQUATION]]. Extending generalized splines are further generalizations for generalized splines. They can also be considered as generalized splines over modules.In this paper, we prove that some of the results for splines can be extended to extending generalized splines when [[EQUATION]] for each vertex [[EQUATION]], and we define a method …

On Construction Of Mannheim Curves With Myller Configuration, Zehra İşbi̇li̇r, Bahar Doğan Yazici, Murat Tosun

Turkish Journal of Mathematics

In this study, our aim is to strengthen the results of the existing literature on the concept of Mannheim curves by using the natural and idiosyncratic structure of Myller configuration. For this purpose, we examine Mannheim curves with Frenet-type frame in Myller configuration for Euclidean 3-space E₃ and Euclidean 4-space E₄. Since the classical Frenet frames in E₃ and E₄ are special cases of Frenet-type frames with Myller configuration in E₃ and E₄, and because of the special and natural structure of the Myller configuration, the Mannheim curves with Frenet frames in …

Biquandle Virtual Brackets And Virtual Knotoids, Nesli̇han Gügümcü, Hamdi̇ Kayaslan

Turkish Journal of Mathematics

In this paper, we introduce invariants of virtual knotoids based on biquandles and biquandle virtual brackets. We show that one of these invariants, namely biquandle virtual bracket matrix, is a proper enhancement of the other invariants introduced in this paper.

Disjoint Supercyclic Pseudo-Shifts, Nurhan Çolakoğlu

Turkish Journal of Mathematics

We  give a characterization for disjoint supercyclicity of a finite number of unilateral pseudo-shift operators on [[EQUATION]]. We also characterize unilateral pseudo-shifts that satisfy the Disjoint Supercyclicity Criterion.

A New Characterization Of Globally Conformal Kenmotsu Manifolds And Lagrangian Submersions, Beran Pi̇ri̇nççi̇, Çağrihan Çi̇men, Deni̇z Ulusoy, Hakan Mete Taştan

Turkish Journal of Mathematics

We give a characterization theorem for a globally conformal Kenmotsu manifold with an illustrative example. Then we study Riemannian, antiinvariant and Lagrangian submersions from globally conformal Kenmotsu manifolds. Initially, we show that the gradient vector field of the conformal transformation and the Lee vector field of the total manifold of a Riemannian submersion is horizontal when the characteristic vector field is a horizontal vector field. We give necessary and sufficient conditions for the integrability and totally geodesicness of vertical and horizontal distributions of antiinvariant and Lagrangian submersions whose total manifolds are globally conformal Kenmotsu. We also give a necessary and …

Biharmonic Curves In Warped Product Manifolds I ×FMN(C), Şaban Güvenç, Ci̇han Özgür

Turkish Journal of Mathematics

We explore the geometric properties of biharmonic curves in warped product manifolds of the form I ×_f Mⁿ(c), where I is an open interval and Mⁿ(c) is a space of constant curvature. By establishing a main theorem, we analyze four distinct cases to reveal deeper curvature-related characteristics of these curves, including situations where they are slant. Finally, we construct three examples in I ×_f S²(1).