Digital Commons Network^™

Grey Wolf Optimization Of Pi Controller For Power Management In Wind Farms: A Novel Approach, Anis Feddaoui, Lotfi Farah, Abdelouahab Benretem, Mohammed Abdeldjalil Djehaf

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes a novel power management strategy for wind farms using a grey wolf optimization (GWO)-based PI controller. The method aims to enhance active and reactive power control in systems employing dou bly fed induction generators. Three control strategies are evaluated—namely, a classical frequency-domain PI controller, an Artificial Neural Network (ANN)-based controller, and the proposed GWO-based PI controller—the last of which represents the main contribution. The classical PI and ANN controllers are included strictly for comparative bench marking. MATLAB simulations demonstrate that the GWO-beased PI controller offers superior dynamic performance, particularly in settling time and overshoot reduction. A power …

Performance Analysis Of Ris-Empowered Ofdm-Im Communications Under Weibull Fading And Joint Tx/Rx I/Q Imbalance, Büşra Ceni̇kli̇oğlu, İbrahi̇m Develi̇, Ayşe Eli̇f Canbi̇len

Turkish Journal of Electrical Engineering and Computer Sciences

A modernist technique, reconfigurable intelligent surface (RIS) provides outstanding signal reflection and amplification, making it highly valuable for upcoming communication systems. Besides, a major contributor is index modulation (IM), attaining superior spectral and energy efficiency, and achieving hardware sufficiency. The primary and novel contribution of this work is the derivation of a highly accurate, closed-form approximate expression for the average bit error rate (ABER) of an orthogonal frequency division multiplexing (OFDM)-IM system operating in the complex and challenging environment characterized by joint transmitter/receiver (Tx/Rx) in-phase and quadrature phase imbalance (IQI) and Weibull fading. This essential analytical achievement is facilitated by …

A Comprehensive Analysis Of Türkiye’S Beaches: Spatial Distribution, Morphometry, And Human Impacts, Muhammed Zeynel Öztürk, Berkay Yilmaz, Abdullah Soykan

Turkish Journal of Earth Sciences

The classification and morphometric characteristics of beaches is crucial for understanding coastal dynamics, evaluating natural and anthropogenic pressures, and supporting effective coastal management and conservation strategies. This is particularly important for countries like Türkiye, where extensive and diverse coastlines play a key role in tourism, the economy, and ecological sustainability. This study presents the first comprehensive, nationwide inventory and characterisation of Türkiye’s beaches, encompassing its 8483 km coastline. Using satellite imagery, 6110 beaches were identified and classified according to environmental conditions, with analyses conducted on their morphological characteristics, sea boundaries, and provincial distributions. The results show that rocky coast and …

Fpga-Based Takagi-Sugeno Fuzzy Controller For Quadrotor Uav Stabilization And Trajectory Tracking, Hocine Khati, Mohamed Amine Nehmar, Arezki Fekik, Mohand Achour Touat, Hand Talem, Rabah Mellah

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents the implementation of a fuzzy logic–based control system on a field-programmable gate array (FPGA) for a quadrotor autonomous aerial vehicle (UAV). The objective is to design and integrate six Takagi–Sugeno fuzzy controllers to regulate roll, pitch, and yaw angles, along with longitudinal, latitudinal, and altitude movements, thereby stabilizing the UAV and enabling it to follow a desired trajectory. Due to the computational complexity of the six controllers, achieving the desired performance requires considerable processing time, which can adversely affect the quadrotor’s mission. Owing to their high processing power and operating frequency, FPGAs enable the control algorithm to …

On The Existence Of Solutions For Nonlinear Third-Order Q-Difference Equations With Boundary Conditions Involving Q-Integrals, İlker Gençtürk

Turkish Journal of Mathematics

In this research, we focus on investigating the existence of solutions for a q-integral boundary value problem associated with third-order nonlinear q-difference equations. To achieve this, we employ two fundamental mathematical tools: the Banach contraction principle and Krasnoselskii’s fixed point theorem, which provide the theoretical framework for our analysis. Furthermore, to illustrate the applicability and robustness of our results, we present and discuss several concrete examples that highlight the practical implications of the proposed methods.

Classifications Of Gradient Almost Ricci Solitons Within The Framework Of Closed Conformal Vector Fields, Akram Ali, Fatemah Mofarreh, Jae Won Lee

Turkish Journal of Mathematics

In this paper, we consider gradient almost Ricci solitons with nonparallel closed conformal vector fields. We classify gradient almost Ricci solitons and show that a complete, noncompact gradient almost Ricci soliton admitting a nonparallel closed conformal vector field, is locally a warped product with Einstein fibers, while in the second case, under additional hypothesis, gradient almost Ricci soliton is totally umbilical if and only if it has constant scalar curvature.

On Trinomial Units Of The Group Ring RcN, César A. Hernandez Melo, Fernanda Diniz De Melo Hernandez, Patricia Massae Kitani

Turkish Journal of Mathematics

Let R be an associative ring with identity, C_n be the cyclic group of order n, and g be a generator of C_n. In this manuscript, for i ∈ N such that 1 ≤ i < n and gcd(i, n) = 1, the algebraic properties of the trinomial elements h_i = -1 + g + g^-i in the group ring RC_n are investigated. More precisely, necessary and sufficient conditions are given for an element h_i to be a unit in RC_n. When h_i is a unit, explicit formulas for computing …

End-Regular Flower Graphs CR,S, Joerg Koppitz, Suparat Phantukang, Phurinut Srisawad, Somnuek Worawiset

Turkish Journal of Mathematics

In the present paper, we study the regularity of the endomorphism monoid of a class of graphs, which generalizes the cycle graph. We give a complete list of all end-regular r × s flower graphs. In particular, for an odd integer s ≥ 3, the s × s flower graph Cs,s has a regular endomorphism monoid, i.e., Cs,s is end-regular. For Cs,s, s ≥ 3 odd, we determine the cardinality and the rank of its endomorphism monoid (including a generating set of minimal size).

Generalized Szász–Mirakyan Operators In The Variation Seminorm, Sare Yumruçali, Harun Karsli, Fatma Taşdelen Yeşi̇ldal

Turkish Journal of Mathematics

The aim of the present paper is to introduce generalized Szász–Mirakyan operators. This article studies the property of variation seminorm and some approximation properties of generalized Szász–Mirakyan operators not only in normed spaces but also in variation seminorm. We obtain convergence properties of our operators using of Korovkin’s theorem and the order of convergence by using a classical approach, the second modulus of continuity and Peetre’s K functional. We also give asymptotic formula and the convergence of the derivatives for these operators. We investigate the variation detracting property of generalized Szász–Mirakyan operators. We show the convergence of generalized Szász–Mirakyan operators …

Some Properties Of Nabla Laplace Transform On Isolated Time Scales, Müfi̇t Şan, Huri̇ye Dağ, Manuel D. Ortigueira

Turkish Journal of Mathematics

This study presents the properties of the bilateral and unilateral nabla Laplace transform, defined on isolated time scales. Furthermore, it explores the nabla Laplace transforms of several elementary functions, employing various proof techniques from real and complex analysis. The findings are illustrated with examples, demonstrating the applicability of these definitions.

From Rough Categories To Rough Groupoids, Mehmet Mustafa Beydaği, Abdullah Fati̇h Özcan, İlhan İçen

Turkish Journal of Mathematics

In this study, we introduce the concepts of rough category and rough groupoid by combining the concepts of category theory and groupoid with rough set theory. We present some properties and examples of these concepts, which are discussed for the first time. Additionally, by defining a rough functor among the rough categories, the category of rough categories were created. Moreover, rough groupoid homomorphism, rough action groupoid, and category of the rough groupoids have been examined algebraically and introduced to the literature.

An Investigation Of New Associated Curves Of A Frenet Curve In Euclidean N-Space, Bedi̇a Meri̇h Özçeti̇n

Turkish Journal of Mathematics

In this study, we introduce the V2-direction curve, Vn−1-direction curve and Vn-direction curve of a Frenet curve in n-dimensional Euclidean space. We provide characterizations and investigate the relationships between the Frenet apparatus of the principal curve and the corresponding apparatus of the direction curves. We also present an application for all direction curves with the results shown using computer code implemented in MATLAB.

New Structures Of Golden Type On The Tangent Bundle, Simona-Luiza Druta-Romaniuc, Cristina-Elena Hretcanu, Aydin Gezer

Turkish Journal of Mathematics

The aim of our paper is to prove the existence of some types of almost (α, p)–golden structures, obtained as general natural lifts of the Riemannian metric from the base manifold M to the total space TM of the tangent bundle. We show that TM, endowed with a general natural almost (α, p)–golden structure (which is a generalisation of the golden structure) and with a general natural metric, is an almost (α, p)–golden Riemannian manifold if and only if the function coefficients of the almost (α, p)–golden structure are related to …

Corrigendum To “ Improved Berezin Radius Inequalities For Functional Hilbert Space Operators” [Turkish Journal Of Mathematics 49 (5) 2025 545-561], Mojtaba Bakherad, Ulaş Yamanci, Mohammad W. Alomari

Turkish Journal of Mathematics

In the article entitled Improved Berezin radius inequalities for functional Hilbert space operators, published in the Turkish Journal of Mathematics, [49 (5): 545-561. https://doi.org/10.55730/1300-0098.3607], the affiliation of the author MOHAMMAD W. ALOMARI was published incorrectly due to an error at the submission stage. The incorrect affiliation was Department of Mathematics, Faculty of Science and Information Technology, Irbid National University, Irbid, Jordan T he correct affiliation is Department of Mathematics, Faculty of Science, Jadara University, Irbid, Jordan T he authors apologize for any inconvenience caused.

The original article can be accessed at: https://doi.org/10.55730/1300-0098.3607

Monotone Positive Solutions Of Impulsive Differential Equations Asymptotic To Nonprincipal Solutions, Si̇bel Doğru Akgöl, Ağacik Zafer

Turkish Journal of Mathematics

This study investigates the asymptotic behavior of monotone positive solutions for a general class of nonlinear second-order impulsive differential equations. By employing the principal and nonprincipal solutions of the associated homogeneous equation, we establish the existence of a monotone positive solution asymptotic to a nonprincipal solution at infinity. To achieve this, we also prove a compactness criterion for an effective use of Schauder’s fixed-point theorem. Under suitable conditions, similarly to the classical case, it is demonstrated that a monotone positive solution asymptotic to a nonprincipal solution exists. A concrete example is given to illustrate the results.

Microplastic Pollution In Marine Ecosystems: Sources, Impacts, Andstakeholder-Based Solutions, Seren Acarer Arat

Turkish Journal of Biology

Microplastics (MPs) are plastic particles of anthropogenic origin with a size range of 1–5000 μm. Marine MP pollution is increasingly recognized as a significant global environmental challenge. MPs, which enter marine ecosystems from land- and marine-based sources, pose physical, chemical, and biological risks due to the adsorption of various pollutants and the formation of biofilm layers. MPs are found in various organisms from lower to higher trophic levels of the marine food web. The negative effects of MPs on marine organisms depend on their abundance, their characteristics, and the exposure time of organisms to MPs. MPs can adversely affect various …

Application Of Biological And Green Nanomaterials In Wastewater Treatment: Techniques For The Effective Removal Of Dyes, Heavy Metals, And Organic Pollutants, Emi̇ne Sena Kazan Kaya, Zeynep Ci̇ğeroğlu, Tansel Kemerli̇ Kalbaran, Başak Temur Ergan, Zeynep Mi̇ne Şenol, Meral Yildirim Yalçin

Turkish Journal of Biology

Background/aim: Wastewater from industrial, agricultural, and residential sources poses significant environmental and public health risks due to the presence of dyes, heavy metals, and organic pollutants. Conventional treatment methods are often inadequate for the complete removal of these pollutants. Therefore, the development of sustainable, environmentally friendly, and highly efficient treatment techniques has become increasingly important. The aim of this review is to evaluate the application of biological and green nanomaterials in wastewater treatment and to compare their effectiveness against different types of pollutants (dyes, heavy metals, and organics).

Materials and methods: This review provides detailed information on the removal of …

Green Carbon Dots In The Era Of Ai: Sustainable Synthesis, Intelligent Drug Delivery, Advanced Diagnostics, And Bioimaging, Emi̇ne Sezer, Fulden Ulucan Karnak, Si̇nan Akgöl

Turkish Journal of Biology

Background/aim: Green carbon dots (GCDs) are a rapidly developing class of nanomaterials that are revolutionizing various scientific disciplines due to their unique optical properties, low toxicity, and sustainable synthesis. This review offers a comprehensive roadmap for the field, emphasizing the synergy between GCDs and artificial intelligence (AI).

Materials and methods: We begin by detailing the sustainable synthesis of GCDs, highlighting green chemistry principles and the transformative role of AI in optimizing their production. Subsequently, we explore the critical characterization of GCDs, including their structural, optical, and biocompatibility assessment. The core of this study explores the diverse biomedical applications of GCDs, …

Principles Of Environmentally Sustainable Agriculture For Building Resilient And Resource-Efficient Food Systems, Ramazan Çakmakçi, Songül Çakmakçi, Muhammet Fati̇h Çakmakçi

Turkish Journal of Biology

As the demand for greater quantities of higher-quality food grows with population expansion, climate change, urbanization, and unsustainable agricultural practices accelerate the loss of arable land, ultimately threatening agricultural sustainability. Population growth necessitates a transition to nutritious, safe, and healthy food production systems that ensure higher yields, less reduced waste, improved social outcomes, and the integration of economic, social, and environmental sustainability principles. Urgent global challenges such as resource depletion, biodiversity loss, and climate change necessitate the protection of ecosystems and the sustainable use of natural resources. Agricultural systems must enhance food production and supply productivity, strengthen system resilience, and …

Artificial Intelligence In Medical And Biological Research: Promise And Perils Of Chatgpt And Deepseek In Advancing Healthcare, Mahmut Enes Kayaalp, Onur Gülteki̇n, Serhat Akçaalan, Hami̇t Çağlayan Kahraman, Hüseyi̇n Nevzat Topçu, Gülşah Kavrul Kayaalp

Turkish Journal of Biology

Background/aim: Artificial intelligence (AI), particularly large language models (LLMs) such as ChatGPT and DeepSeek, is being increasingly applied in clinical care, research, and education. The aim of this review is to examine how these tools may transform the conduct of medical and biological research and to define their limitations.

Materials and methods: A narrative synthesis of the literature was performed, encompassing studies published between 2020 and 2025. Peer-reviewed journals, systematic reviews, and high-impact original research articles were included to ensure an evidence-based overview. The principle applications, validation metrics, and clinical implications across orthopedics, oncology, cardiology, internal medicine, and the biological …

A Systematic Review Of Machine Learning In Heart Disease Prediction, Tathagat Banerjee, İshak Paçal

Turkish Journal of Biology

Background/aim: Cardiovascular diseases (CVDs) are a leading cause of global mortality, prompting the need for advanced predictive tools. While machine learning (ML) offers a powerful solution, there are significant challenges to clinical translation. This systematic review synthesizes the current state of ML in heart disease prediction, evaluating algorithmic performance, data utilization, and key translational challenges.

Materials and methods: Following PRISMA guidelines, a systematic search of literature published up to 2025 was conducted. From an initial pool of over 2500 records, a rigorous screening process yielded 65 studies for in-depth qualitative synthesis.

Results: Analysis showed that ensemble learning models dominate prediction …

Flavonoids And Phenolic Compounds: A Promising Avenue For Neurodegenerative Disease Therapy, Tesli̇me Özge Şahi̇n, Özge Cemali̇, Merve Özdemi̇r, Şeri̇fe Ayten, Duygu Ağagündüz

Turkish Journal of Biology

Background/aim: Neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and ALS are characterized by a progressive loss of nerve cells, for which no definitive cure currently exists. These conditions share common pathological mechanisms, including chronic neuroinflammation, oxidative stress, protein aggregation, and mitochondrial dysfunction. Flavonoids and other plant-derived phenolic compounds have recently attracted attention for the treatment of such conditions due to their antiinflammatory and antioxidant properties. This review explores the neuroprotective mechanisms of flavonoids and evaluates their potential for the prevention and treatment of neurodegenerative diseases.

Materials and methods: A literature search of the Web of Science, PubMed, and ScienceDirect databases …

Tumor-Specific Cytotoxicity Of Pyrazole-Based Chalcone Derivatives In Human Oral Squamous Cell Carcinoma Cell Lines, Mehtap Tuğrak Sakarya, Hali̇se İnci̇ Gül, Hiroshi Sakagami, Junko Nagai, Yoshihiro Uesawa, Kenjiro Bandow

Turkish Journal of Biology

Background/aim: Pyrazole-based chalcone hybrids are notable in medicinal chemistry for their potential biological activity, although their tumor-specific cytotoxicity and mechanisms remain unknown in OSCC cells. This first study of pyrazole-chalcone hybrids in OSCC cells explores the tumor-selective cytotoxic effects and underlying cell death mechanisms triggered by a series of 10 newly synthesized pyrazole-based compounds (MS1MS10) in OSCC cell lines. Material and methods: The cytotoxic effects of the compounds were assessed using the MTT assay on four human OSCC cell lines and three types of normal human oral cells. The tumor-selectivity index (TS) and potency-selectivity expression (PSE) were calculated, and active …

The Effects Of The Combined Use Of Carbon Quantum Dots And Antibacterial Agents On Pathogenic Bacteria, Derya Doğanay, İbrahi̇m Serkan Avşar, Şevval Maral Özcan Aykol, Gamze Çamlik, Besa Bi̇lakaya, İsmai̇l Tuncer Deği̇m

Turkish Journal of Biology

Background/aim: This study evaluates the challenges associated with overcoming antimicrobial resistance and innovative approaches to combat multidrug-resistant (MDR) bacterial infections.

Materials and methods: Novel codoped carbon quantum dots (CCQDs) were synthesized using citric acid as the carbon source and L-cysteine as the nitrogen codoping atom. The formulation in which citric acid was retained was designated as CCQDs-1, whereas the purified version, from which citric acid was removed, was termed CCQDs-2. The antibacterial properties of CCQDs-1 and CCQDs-2 were compared using the agar well diffusion method. This study comprehensively characterizes these nanomaterials and evaluates their antibacterial potential, both alone and in …

Effect Of Three Different Crop Rotations On Seed Productivity And Soil Properties In Organic Tomato Seed Production: A Comprehensive 13-Year Field Study With Three Cycles, Gülay Beşi̇rli̇, İbrahi̇m Sönmez, Bariş Albayrak, Mehmet Şi̇mşek, Zühtü Polat, Nesri̇n Uzunoğullari, Nesri̇n Tunali̇, Gürsel Çeti̇n, Razi̇ye Kul

Turkish Journal of Agriculture and Forestry

This study was carried out to investigate the effects of three different crop rotation practices and three cycle periods on tomato seed yield and quality and some soil characteristics in organic farming conditions. The crop rotations included tomato as the primary crop along two intercrops (CR-1: tomato-leek-okra crop rotation, CR-2: tomato-head cabbage-lettuce crop rotation, CR-3: tomato-watermelon-onion crop rotation). At the end of the study, seed yield and quality of other vegetable species (leek, okra, head cabbage, lettuce, watermelon, and onion) included in the trial along with tomato, seed-borne pathogens, and some soil properties of the trial area were determined. The …

Changes In Phenolics And Organic Acid Contents Of Postharvest Eggplants In Response To Preharvest Fertilizer Applications And Postharvest Edible Coatings, Nuretti̇n Yilmaz, Şeyda Çavuşoğlu

Turkish Journal of Agriculture and Forestry

Pre- and postharvest techniques play a key role in improving the quality and shelf life of fresh horticultural products. The aim of this 2-year study was to evaluate the postharvest phenolic and organic acid content in eggplants under different fertilizers and postharvest treatments. Before planting, all plots were treated with 2000 cc da−1 of humic acid through a drip irrigation system. Plots treated only with humic acid were considered the control group. Fifteen days after planting, the other plots were treated with 2000 cc da−1 of liquid vermicompost fertilizer or 2000 cc da−1 of organomineral fertilizer via drip irrigation. Postharvest, …

Development Of Functional Cottage Cheese Enriched With Elderberry Pomace Powder: Nutritional And Antioxidant Enhancement, Roxana Nicoleta Ratu, Florina Stoica, Ioana Cristina Crivei, Ionut Dumitru Velescu, Florin Daniel Lipsa, Andreea Bianca Balint, Romina Alina Marc, Petru Marian Cârlescu, Marius Giorgi Usturoi, Emi̇ne Maci̇t

Turkish Journal of Agriculture and Forestry

The increasing demand for sustainable and functional foods has driven interest in utilising agro-industrial by-products, such as elderberry pomace, to enhance the nutritional and antioxidant properties of food products. This study aimed to develop a functional cottage cheese enriched with elderberry pomace powder (EPP) and evaluate its nutritional composition, antioxidant potential, sensory acceptability, and textural properties. Cottage cheese samples were formulated with EPP at concentrations of 3% and 5%, alongside a control sample devoid of EPP. The results showed that the inclusion of EPP significantly increased the levels of anthocyanins, flavonoids, and polyphenols, along with enhanced antioxidant activity, compared to …

Determinants Of Job Performance In Forestry Organizations: A Structural Equation Modeling Approach On Technical Staff In The Mediterranean Region, Mehmet Pak, Ari̇f Okumuş

Turkish Journal of Agriculture and Forestry

This study aimed to explore the individual, institutional, and job-related factors influencing the job performance of technical staff in the Regional Forestry Directorates located in the Mediterranean Region of Türkiye. Data were collected through a mixed-method approach, including mostly face-to-face interviews, complemented by partially online questionnaires. Data were obtained from 650 technical staff, including regional directors, enterprise managers, section chiefs, and forest engineers. Structural equation modeling was applied, and variables were validated using confirmatory factor analysis. Model fit indices were within acceptable limits (e.g., RMSEA = 0.069, CFI = 0.838, GFI = 0.809). The results indicate that institutional factors had …

Nitrogen Management In Enhancing Raspberry (Rubus Idaeus L.) Productivity And Sustainable Development In Fruit Cultivation, Aleksandar Leposavić, Žaklina Karaklajić-Stajić, Sezai̇ Erci̇şli̇, Darko Jevremović, Ivana S. Glišić, Branko Popović, Olga Mitrović

Turkish Journal of Agriculture and Forestry

This study investigated the effect of reduced nitrogen (N) fertilizer dosage on the vegetative and generative potential, physical and chemical characteristics, and fruit yield of raspberry (Rubus idaeus L.). Two raspberry cultivars (Willamette and Meeker) were treated with low and high doses of calcium ammonium nitrate and urea over 3 consecutive years (2021–2023) in Western Serbia. Basic floricane traits and fruit quality parameters were analyzed using widely accepted methodologies. The results showed significant variations in primocane growth, floricane traits, and berry quality in response to different N fertilizer doses, whereas soluble solid content (SSC) was more stable. Lower N fertilizer …

The Impact Of Endogenous And Exogenous Fungi In Saline-Alkali Soil On The Growth And Root System Of Pine Trees, Chunfeng Shi, Zhixin Ju, Kan Gao, Wenzhong Fan, Bo Yang

Turkish Journal of Agriculture and Forestry

The objective is to explore planting methods that enhance the ability of black pine to cope with salt stress environments, improve its growth under such conditions, and observe its growth and physiological characteristics under various experimental conditions. For this purpose, endophytic mycorrhizal Indian pear-shaped fungus and ectomycorrhizal two-colored wax mushrooms were selected and inoculated onto potted black pine seedlings, and a control group was set up. After inoculation, the mycorrhizal infection rate, salt damage symptoms, growth rate, root parameters, and various physiological indicators under different salt stress durations were evaluated. Results showed that as the salt concentration was raised to …