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Article Citation - WoS: 11Citation - Scopus: 11Experimental and Modeling Studies of a High-Temperature Electrochemical Hydrogen Compressor(Pergamon-elsevier Science Ltd, 2024) Durmus, Gizem Nur Bulanik; Kuzu, Cemil; Devrim, Yilser; Colpan, C. Ozgur; Bulanık Durmuş, Gizem NurSome non-technical factors such as economics and logistics prevent hydrogen (H2) tech-nologies from becoming more widespread in daily life. Today, the prevalence of H2 tech-nologies requires new technological developments. Electrochemical hydrogen compressors (ECHC) are of great interest due to their ability to pressurize and purify in one step. In this study, the electrochemical H2 compression performance of high phosphoric acid (PA) doped poly 2,2-m-phenylene-5,5-benzimidazole (PBI) membrane-based HT-ECHC under high temperature and non-humid conditions was investigated through both an experimental and a numerical approach. The H2 compression capacity of HT-ECHC at different operating voltages was examined by performance tests at 160 degrees C, and it was determined that the electrochemical compression performance increased with increasing operating voltage. It was observed that the current density values also increased with increasing voltage, and it was determined that a current density of 61.2 A was obtained at 1 V. As a result of the tests, H2 was successfully compressed from atmospheric pressure to 60 bar by HT-ECHC without any gas leakage. The results of the developed model were compared with the experimental performance test data, and the variation of molar flow, cell voltage, and cell efficiency over time was examined. It has been determined that the back diffusion from the cathode to the anode in the cell increases with the increasing operating voltage of HT-ECHC and therefore the cell efficiency decreases. It has been evaluated that the developed model and experimental results are in good agreement. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Role of Latissimus Dorsi-Thoracolumbar Fascia Complex Stretching on Pain and Pain-Related Parameters in Patients With Chronic Low Back Pain: A Randomised Clinical Trial(Wiley, 2025) Ulug, Naime; Kodak, Seyde Busra; Kodak, Muhammed Ihsan; Aslan, Sema NurBackground Fascial stretching is gaining interest as a potential intervention for pain management. However, evidence regarding the effect of latissimus dorsi-thoracolumbar fascia (LD-TLF) complex stretching in patients with chronic low back pain (CLBP) remains limited. Therefore, this study aimed to investigate the effects of LD-TLF complex stretching on pain-related factors and disability in patients with CLBP. Methods Thirty patients with CLBP were randomly assigned to a study group (n = 15; 7 men, 8 women) and a control group (n = 15; 7 men, 8 women). The study group received 4 weeks of LD-TLF complex stretching in combination with conventional physiotherapy, while the control group received conventional physiotherapy only. Outcomes were assessed before and after the interventions, including primary measures of pain pressure thresholds (PPT) at thoracolumbar fascia levels (L1, L3 and 12th costa), and secondary measures included the Pain Sensitivity Questionnaire (PSQ), the effects of pain on daily activities measured by the Brief Pain Inventory (BPI), and disability assessed by the Oswestry Disability Questionnaire (ODQ). Results Pre- and post-treatment PPTs, at the L1, L3 vertebrae and 12th costa levels, demonstrated significant differences between the study group and control groups. Post-treatment thresholds were significantly higher compared to pre-treatment thresholds (p < 0.001, eta p(2) = 0.67; p < 0.001, eta p(2) = 0.61; p < 0.001, eta p(2) = 0.74). Additionally, significant improvements were found in PSC, BPI and ODQ scores in the study group compared to the control group (p < 0.05). Conclusion The results of this study suggest that stretching the LD-TLF complex may be a beneficial addition to the conventional physiotherapy approach for patients with CLBP. Specifically, LD-TLF complex stretching, when used in combination with conventional physiotherapy, appears to provide improved pain thresholds, decreased pain sensitivity and pain during activity, as well as reduced disability compared to conventional physiotherapy alone in patients with CLBP.Article Citation - WoS: 2Citation - Scopus: 2The Detailed Transseptal Puncture Technique for Optimal Closure in Patients With a Patent Foramen Ovale(Frontiers Media Sa, 2024) Ilkay, Erdogan; Saricam, Ersin; Kacmaz, Fehmi; Yakici, Aysel; Koca, Cigdem; Ozeke, Ozcan; Onal, Mehmet ZulkufBackground The closure of a patent foramen ovale (PFO) using transseptal puncture has particular advantages and disadvantages. Thus, transseptal puncture should be re-evaluated in detail. Aims We aimed to assess the effectiveness of the detailed transseptal puncture technique in patients who underwent PFO closure due to cryptogenic stroke or transient ischemic attack in terms of residual shunts and atrial fibrillation. Methods We prospectively analyzed 144 consecutive patients who underwent PFO closure by the detailed transseptal puncture technique between February 2013 and April 2023 in two centers. All of the patients had a >10 mm long-tunnel PFO. Results The procedural success rate was 100%. However, after the procedure, moderate pericardial effusion developed in one patient (0.7%) and an acute pulmonary embolism related to femoral vein thrombosis was observed in one patient (0.7%) during the first month. Complications related to the procedure were noted in two patients (1.4%) during the first month of follow-up. Residual shunts were observed in 1.4% of cases after PFO closure. Conclusion We demonstrated that the detailed transseptal technique is safe and effective for PFO closure. The detailed transseptal PFO closure technique significantly reduced the risk of atrial fibrillation, and the occurrence of residual shunts was significantly low following the closure.Article Makroekonomik ve Sosyo-Politik Endeks Nitelikli Çalışan başına Reel GSYH’yi Nasıl Etkiler? Türk Cumhuriyetleri’nden Kanıtlar(Ahmet Yesevi Univ, 2023) Kucuker, Mustafa Can; Omay, Tolga; Celik, Esref Ugur; Erdal, Fehmi BuğraBu çalışmada, nitelikli çalışan başına reel GSYH düzeyini etkileyen sosyoe- konomik faktörler üzerinde durulmuştur. Bu amaçla Türk Cumhuriyetleri için makroekonomik ve sosyo-politik performans endeksleri oluşturulmuştur. Yeni oluşturulan bu endeksler kullanılarak, nitelikli çalışan başına düşen reel GSYH düzeyinin belirleyicileri literatürde ilk kez analiz edilmektedir. Ampi- rik sonuçlar, belirli eşik düzeylerinin nitelikli çalışan başına reel GSYH düze- yini önemli ölçüde etkilediğini göstermektedir. Sonuç olarak, çalışmada yer verilen ülkelerin politika yapıcıları, ülkelerinin refahı açısından iyi organize edilmiş politikalar yürütmek için makroekonomik ve sosyo-politik perfor- mans endekslerin eşik değerlerini ciddi şekilde göz önünde bulundurmalıdır.Article Citation - Scopus: 1Patient Safety in Healthcare: A Proposal for Ensuring the Use of Regulation-Compliant Safety Devices(Springer Heidelberg, 2025) Bayrak, TuncayMedical devices used in health care should fulfill the requirements of the technical regulations to protect patient health. Difficulties in enforcing stricter rules in the new medical device regulations may negatively affect the continuity of care. This study examines the status of manufacturers' compliance with medical device regulations, based on predefined criteria, and proposes a collaborative action plan and an approach to verify regulatory compliance. We conducted a nationwide survey comprising questions grouped by criteria to understand the status of the manufacturers in terms of compliance with the Medical Device Regulation. Four hundred sixty-seven manufacturers participated in the survey. We achieved a Cronbach's alpha of 0.77, which indicates that the survey is statistically reliable. We applied the independent samples t-test to the responses to determine significant features per question and employed factor analysis to investigate the relationships of the questions. The results of independent samples t-tests showed statistically significant differences across groups in replies to several survey items (p < 0.05), indicating that participants' opinions varied based on their demographic characteristics. We applied Exploratory Factor Analysis to introduce the relationships between the questions. The analysis revealed that manufacturers continue to face substantial challenges in acquiring sufficient knowledge and operational capability to meet MDR requirements. In light of these findings, we focused on the person responsible for regulatory compliance, who plays a central role in maintaining regulatory compliance within manufacturing organizations. We proposed an action plan at the macro level to introduce more effective action plans in cooperation with other stakeholders, including healthcare providers, and a verification approach for regulatory compliance to enhance the Person Responsible for Regulatory Compliance's competence. Manufacturers should implement effective postmarketing clinical follow-up plans involving device-oriented parameters for monitoring in the healthcare system, especially in collaboration with health professionals.Article Epistemic Extraction Zones in Migration Studies: Rethinking Over-Research and Research Fatigue Among Syrian Refugees in Turkey(Wiley, 2025) Ozdemir, ZelalThis paper explores the phenomenon of over-research among Syrian refugees in Turkey, highlighting how sustained and repetitive research attention has created research saturation zones that shape both refugee experiences and knowledge production. Drawing on unstructured conversations with six Syrian refugees in Ankara, the study examines how research fatigue manifests not only as reluctance to participate but also as strategic responses through which refugees navigate frequent encounters with researchers. While existing literature has addressed research fatigue and ethics in refugee studies, less attention has been given to how academic incentives, humanitarian logics, and policy imperatives intersect to produce systematic inequalities in knowledge production. To address this gap, the paper advances the concept of epistemic extraction zones, referring to contexts where knowledge is persistently mined from marginalized communities to satisfy institutional demands with limited reciprocity or epistemic agency. This conceptual lens shifts the debate from individual withdrawal to the structural political economy of knowledge production. The analysis identifies three key dynamics. First, the emergence of research saturation zones in contexts of protracted displacement, where the same communities are repeatedly targeted for study; second, refugees' strategic yet ambivalent engagement with research, combining pragmatic hope with critical awareness of its limited effects; and third, the paradoxical consequences of over-research, where intensified attention produces epistemic extraction that narrows the circulation of knowledge and reinforces hierarchies. The article also reflects critically on the researcher's own position within these dynamics. By theorizing epistemic extraction zones, the paper contributes not only to refugee studies but also to broader sociological debates on power, inequality, and the ethics of knowledge production, highlighting the need for more reflexive and politically accountable research practices.Article Citation - WoS: 1Citation - Scopus: 2Existence of Solutions for Odd-Order Multi-Point Impulsive Boundary Value Problems on Time Scales(Walter de Gruyter Gmbh, 2022) Georgiev, Svetlin G.; Akgol, Sibel Dogru; Kus, Murat Eymen; Doǧru Akgöl, Sibel; Eymen Kuş, MuratUsing a fixed point theorem due to Schaefer, the existence of solutions for an odd-order m-point impulsive boundary value problem on time scales is obtained. The problem considered is of general form, where both the differential equation and the impulse effects are nonlinear. Illustrative examples are provided.Article Citation - WoS: 21Citation - Scopus: 22Sensitivity Analysis of the Effect of Current Mood States on the Thermal Sensation in Educational Buildings(Wiley-hindawi, 2022) Ozbey, Mehmet Furkan; Ceter, Aydin Ege; Orfioglu, Sevval; Alkan, Nese; Turhan, CihanAdaptive thermal comfort is a model which considers behavioral and psychological adjustments apart from Fanger's Predicted Mean Vote (PMV)/Percentage of Dissatisfied (PPD) method. In the literature, the differences between the PMV/PPD method and adaptive thermal comfort were mainly considered in aspects of behavioral adjustments in an environment. Conversely, limited studies related to psychological adjustments were considered in detail for thermal comfort. This study purposes to investigate the effects of current mood state subscales on thermal sensation of the occupants for the first time in the literature. To this aim, the Profile of Mood States (POMS) questionnaire is used to determine the mood state of the occupants with six different subscales: Anger, Confusion, Vigor, Tension, Depression, and Fatigue. The experiments were conducted in a university study hall in Ankara, Turkey, which is in warm-summer Mediterranean climate (Csb) according to Koppen-Geiger Climate Classification. The distributions of each subscale were examined via Anderson Darling and Shapiro-Wilk tests accordingly given responses from the occupants. The sensitivity analysis was applied to the six subscales of the POMS with Monte Carlo simulation method by considering the distributions of each subscale. The results revealed that the current mood state has a crucial effect on the thermal sensation of the occupants. The subscales of the Depression and Vigor were found as the most vital ones among the six subscales. Only the pure effects of the Vigor and Depression would change the thermal sensation of the occupants 0.31 and 0.30, respectively. The Confusion was determined as the least effective subscale to the thermal sensation of the occupants. Moreover, with the combination of all the six subscales, the thermal sensation might change up to 1.32. Findings in this study would help researchers to develop the personalized thermal comfort systems.Article Robust Divergence-Based Tests of Hypotheses for Simple Step-Stress Accelerated Life-Testing Under Gamma Lifetime Distributions(Elsevier, 2026) Balakrishnan, Narayanaswamy; Jaenada, Maria; Pardo, LeandroMany modern devices are highly reliable, with long lifetimes before their failure. Conducting reliability tests under actual use conditions may require therefore impractically long experimental times to gather sufficient data for developing accurate inference. To address this, Accelerated Life Tests (ALTs) are often used in industrial experiments to induce product degradation and eventual failure more quickly by increasing certain environmental stress factors. Data collected under such increased stress conditions are analyzed, and results are then extrapolated to normal operating conditions. These tests typically involve a small number of devices and so pose significant challenges, such as interval-censoring. As a result, the outcomes are particularly sensitive to outliers in the data. Additionally, a comprehensive analysis requires more than just point estimation; inferential methods such as confidence intervals and hypothesis testing are essential to fully assess the reliability behaviour of the product. This paper presents robust statistical methods based on minimum divergence estimators for analyzing ALT data of highly reliable devices under step-stress conditions and Gamma lifetime distributions. Robust test statistics generalizing the Rao test and divergence-based tests for testing linear null hypothesis are then developed. These hypotheses include in particular tests for the significance of the identified stress factors and for the validity of the assumption of exponential lifetimes.Article Citation - WoS: 11Citation - Scopus: 20Reinforcement Learning Using Fully Connected, Attention, and Transformer Models in Knapsack Problem Solving(Wiley, 2022) Yildiz, Beytullah; Yıldız, Beytullah; Yıldız, BeytullahKnapsack is a combinatorial optimization problem that involves a variety of resource allocation challenges. It is defined as non-deterministic polynomial time (NP) hard and has a wide range of applications. Knapsack problem (KP) has been studied in applied mathematics and computer science for decades. Many algorithms that can be classified as exact or approximate solutions have been proposed. Under the category of exact solutions, algorithms such as branch-and-bound and dynamic programming and the approaches obtained by combining these algorithms can be classified. Due to the fact that exact solutions require a long processing time, many approximate methods have been introduced for knapsack solution. In this research, deep Q-learning using models containing fully connected layers, attention, and transformer as function estimators were used to provide the solution for KP. We observed that deep Q-networks, which continued their training by observing the reward signals provided by the knapsack environment we developed, optimized the total reward gained over time. The results showed that our approaches give near-optimum solutions and work about 40 times faster than an exact algorithm using dynamic programming.
