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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14411/18
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Article Global De-Democratization and Women’s Political Empowerment in the 2000s(Pergamon-Elsevier Science Ltd, 2026-07) Ertan, Senem; Keysan, Asuman ÖzgürSince 2000, democratic backsliding led to changes in the gender regime, a deterioration in gender equality, and a decline of women's empowerment demonstrated in many country studies and small-N comparisons. Given the lack of large-N cross-national analyses, this paper seeks to close the gap by examining the impact of dedemocratization on women's political empowerment by comparing 162 countries. The findings highlight that lower levels of democracy are associated with lower levels of women's political empowerment. Indeed, not only cross-national, but also within-country changes in democracy levels have substantial short-term and long-term effects on women's political empowerment. Although securing representative democracy with free political parties, free and fair elections, or an effective parliament is important to politically empower women, this study demonstrates that women's political empowerment is sustained in countries where the rule of law and participatory democratic rule are strongly consolidated.Article Perceived Health Inequalities in OECD Countries: A Macro-Level Cluster Analysis(Pergamon-Elsevier Science Ltd, 2026-06) Bulut, TevfikAlthough perceived health inequalities remain a persistent problem across the OECD, the interaction of socioeconomic factors with sex and their structural differences have not yet been sufficiently investigated. Existing one-dimensional analyses are inadequate in explaining the complex nature of these inequalities at the macro level. This study examines perceived health inequalities in terms of socioeconomic status and sex and develops a novel typology that groups countries according to their inequality profiles. The analysis uses aggregated data from 39 countries covering the period 2003-2024. Linear Mixed Effects Models were used for regression analyses, and the K-means clustering algorithm was used to construct the country typology. The results show that at the macro level, higher income is strongly associated with better perceived health (beta = 20.60, p < 0.001). Remarkably, the positive relationship between education and health is significantly stronger in females compared to males. The negative interaction coefficient obtained (beta(interaction) = -10.79, p < 0.001) indicates that the sex-based health gap narrows at higher education levels. Cluster analysis identified two distinct groups of countries: High Inequality Profile and Low Inequality Profile. These findings highlight the potential equalizing role of education and reveal that health inequalities are not homogeneous. Consequently, policy interventions should target disadvantaged groups intersectionally and be designed according to the specific structural characteristics of each country.Article Performance Assessment of a Solar-Geothermal Based Organic Rankine Cycle System Producing Green Hydrogen(Pergamon-Elsevier Science Ltd, 2026-02) Atak, Yagmur Nalbant; Nalbant Atak, YagmurThis study presents a comprehensive thermodynamic (energy and exergy) analysis of a solar-geothermal-based Organic Rankine Cycle (ORC) system integrated with a proton exchange membrane (PEM) electrolyzer for green hydrogen production. The system simultaneously harnesses the continuous heat of a geothermal source and the intermittent solar thermal input to ensure stable hydrogen generation. The effects of key operating parameters (solar radiation intensity, production well temperature, inlet temperature of the PTSC fluid, and ORC and PTSC working fluid types were investigated. The results reveal that higher solar radiation intensities significantly enhance both power generation and hydrogen yield, increasing the hydrogen production rate from 22.9 to 24.3 kg/h and the net electrical output from 4.17 to 4.41 MW. Similarly, increasing the geothermal well temperature from 400 K to 600 K significantly enhances hydrogen production, rising from 15.9 to 45.5 kg/h, and increases the net power output by approximately 185 %. However, the exergy efficiency decreases slightly from 0.26 to 0.17 due to increased irreversibilities at higher temperatures. The optimal working pair was determined to be R134a for the ORC and Therminol VP1 for the PTSC, achieving an electrical efficiency of 9.27 %, exergy efficiency of 25.13 %, and hydrogen production rate of 29.02 kg/h. In addition, the exergy analysis showed that the PTSC (similar to 35 %) and condenser (similar to 24.6 %) are the dominant sources of irreversibility. Finally, the Taguchi optimization identified the optimal configuration (Gb = 3.50 x 10(-4) MW/m(2), T-a = 500 K, T-11 = 600 K, and ORC fluid = R134a) yielding the highest overall efficiency and robust performance under variable operating conditions.Article Legalizing Anti-Gender Ideology and Civil Society Resistance in Turkey(Pergamon-Elsevier Science Ltd, 2026-05) Keysan, Asuman Ozgur; Özgür Keysan, AsumanThis study investigates how feminist, LGBTQI+, labour, and human rights organisations in Turkey frame and negotiate the legal institutionalisation of anti-gender ideology and how these processes generate strategic yet fragile cross-movement alliances. Drawing on Benford and Snow's framing theory and Yuval-Davis's transversal politics, the analysis is based on semi-structured interviews conducted with activists from ten organisations between April and June 2025 and organisational documents. The study conceptualises anti-gender politics in Turkey not as a societal backlash but as a state-driven, multi-layered project of "masculinist entrenchment (Yetis, & O<spacing diaeresis>zd & uuml;zen, 2024)" that restructures legal, ideological, and affective arenas. The findings demonstrate that activists increasingly reframe anti-gender assaults as systemic attacks on democracy, rights, and equality, producing a shift from issue-based coordination to what this article terms "strategic coexistence", a hybrid alliance formed across previously distant ideological and organisational positions. Diagnostic framing identifies anti-gender reforms as an existential threat, prognostic framing centres on alliance-building, movement memory, and inclusive organisational practices and motivational framing foregrounds shared destiny, solidarity, and the symbolic significance of LGBTQI+ rights. The analysis reveals that while this recontextualisation widens the basis for coalition, the resulting alliance remains structurally unbalanced and fragile. Hierarchical power relations, uneven exposure to political risk, and selective silence, particularly regarding LGBTQI+ concerns, limit the depth and durability of alliances. In this context, LGBTQI+ rights serve both as a catalyst for broad-based mobilisation and as a litmus test for democratic commitment, disclosing the limitations of transversal solidarity under authoritarian regimes.Article A Computationally Efficient Approximation for Fractional Differencing: First-Order Operators(Pergamon-Elsevier Science Ltd, 2026-04) Omay, Tolga; Baleanu, DumitruThis paper introduces the First-Order Fractional Differencing (FOFD) operator that substantially reduces the computational burden of fractional differencing for large-scale applications. While the standard Gr & uuml;nwald-Letnikov (GL) operator requires O(T2) operations for a series of length T, and recent FFT-based methods achieve O(T log T), our FOFD operator requires only O(T) operations through a simple two-point recursion. We develop an optimal weight calibration framework that ensures this computational efficiency does not compromise statistical accuracy, deriving a general formula wopt = d & sdot; (1-0.9 rho)beta(p) that adapts to the persistence structure of autoregressive processes. Empirical applications demonstrate substantial improvements: for the Chicago Fed National Financial Conditions Index with extreme persistence (rho= 0.992), optimal weight calibration reduces approximation error by 93% while preserving the autocorrelation structure of the GL operator. For a series of 10,000 observations, our method requires 20,000 operations compared to 530,000 for FFT-based methods and 50 million for standard implementations-enabling fractional differencing in real-time and high-frequency contexts previously infeasible due to computational constraints. The method's simplicity, requiring no specialized libraries and providing direct implementation through our calibration formula, makes it immediately accessible to practitioners while maintaining the long-memory properties essential for financial time series modeling.Article Prevalence of Toxoplasma Gondii in Patients with Schizophrenia and Its Association with Clinical Symptoms(Pergamon-Elsevier Science Ltd, 2025-10) Kurkcu, Muhammed Furkan; Korkut, Gizem; Varli, Mehmet Ridvan; Yilmaz, Gulsum; Usluca, Selma; Bakir, AyferBackground: Schizophrenia is a multifactorial neuropsychiatric disorder influenced by both genetic predisposition and environmental factors. Recent evidence suggests a possible link between latent Toxoplasma gondii infection and schizophrenia, though the underlying mechanisms remain unclear. Objective: To compare the seroprevalence of T. gondii in patients with schizophrenia and healthy individuals, and to evaluate the relationship between seropositivity and clinical parameters. Methods: A total of 265 participants (155 schizophrenia patients and 110 healthy controls) were enrolled. IgG and IgM antibodies were detected using electrochemiluminescence immunoassay (ECLIA), avidity was assessed using ELISA, and DNA presence was tested with real-time PCR. Clinical symptoms were evaluated using the Brief Psychiatric Rating Scale (BPRS). Statistical analysis included logistic regression and non-parametric tests (p < 0.05). Results: T. gondii IgG seropositivity was significantly higher in schizophrenia patients (29 %) than in controls (18.2 %) (p = 0.044, OR = 1.84; 95 % CI: 1.01-3.34). IgM positivity and DNA detection did not differ significantly. All seropositive participants showed high IgG avidity, indicating latent infection. BPRS scores and illness duration were higher in IgG-positive individuals, but the differences were not significant. Conclusion: Latent T. gondii infection may be associated with schizophrenia. However, further multicenter studies integrating molecular and serological approaches are needed to clarify its role in disease pathogenesis.Article First-Principles Investigation of Kaolinite/YSZ Heterostructure for Solar-Driven Photocatalytic Hydrogen Production(Pergamon-Elsevier Science Ltd, 2025-09) Park, Jongee; Yu, Eunmi; Fatima, Syeda AfrinishThis work employs density functional theory (DFT) to elucidate the structural, electronic, and photocatalytic properties of a kaolinite/yttria-stabilized zirconia (Kaol/YSZ) heterostructure tailored for solar-driven hydrogen generation. The lattice mismatch between Kaol(001) and YSZ(111) was determined to be 4.4 % along the a-axis and 2.2 % along the b-axis. Two interface terminations were modeled: an O-terminated Si-O surface and an OH-terminated Al-OH surface. The OH-terminated interface demonstrated a stronger interfacial binding energy (-9.32 eV per cell) and enhanced thermodynamic stability, indicating its suitability for photocatalytic water splitting. Electronic structure analysis reveals that the Kaol/YSZ heterostructure exhibits a narrowed band gap of 1.46 eV relative to the isolated components, which promotes enhanced visible-light absorption. A type-II band alignment is observed, facilitating photoinduced electron transfer from the conduction band of YSZ to the conduction band of Kaol and promoting efficient charge separation. Hirshfeld charge analysis confirms the existence of a built-in electric field at the interface that further drives charge migration. Calculated optical absorption spectra shows a red shift in the heterostructure's absorption edge, extending its photoresponse into the visible region. Under simulated solar irradiation, photogenerated electrons preferentially migrate to Kaol for proton reduction, while holes remain on the YSZ surface to oxidize water, enabling simultaneous H2 evolution and O2 evolution pathways. These findings highlight the promise of the Kaol/YSZ heterostructure as a robust visible-light photocatalyst for sustainable hydrogen production and environmental remediation.Article Citation - WoS: 15Citation - Scopus: 13A Review on Membranes for Anion Exchange Membrane Water Electrolyzers(Pergamon-Elsevier Science Ltd, 2026-01) Altinisik, Hasan; Celebi, Ceren; Ozden, Adnan; Devrim, Yilser; Colpan, C. Ozgur; Ozgur Colpan, C.Anion exchange membrane water electrolyzers (AEMWEs) - using water and renewable electricity as the input - provide a sustainable pathway to hydrogen production. AEMWEs perform the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) with modest overpotentials at practical current densities (>1 A cm(-2)). The recent catalysis, component, and system-level breakthroughs have enabled significant improvements in current densities and energetic efficiencies. The challenge, however, is to maintain these impressive activities and efficiencies through long-term operation at scale. High-performance, efficient, stable, and economically viable AEMWEs require high-performance, low-cost, and scalable anion exchange membranes (AEMs). This Review provides an overview of physical, chemical, and transport properties of commercial and non-commercial AEMs. The article discusses the operating principles, structures, characteristics, strengths, and weaknesses of conventional and emerging AEMs, along with their performance and stability implications in AEMWEs. The article highlights the characteristics that have intricate implications on performance, stability, and cost. It discusses recent advances and best practices to combine high-performance, efficiency, stability, and low-cost in a single AEM structure. The Review highlights the trade-offs between AEM characteristics, with an overview of emerging approaches that would overcome performance, stability, and cost challenges. The Review concludes by highlighting the research gaps and providing research directions with the potential to take the technology a step closer to wide-scale deployment.Article Citation - WoS: 5Citation - Scopus: 5The Design and Techno-Economic Evaluation of Wind Energy Integrated On-Site Hydrogen Fueling Stations for Different Electrolyzer Technologies(Pergamon-Elsevier Science Ltd, 2025-08) Devrim, Yilser; Ozturk, Reyhan AtabayHydrogen refueling stations (HRS) integrated with renewable energy sources present a pivotal solution for achieving sustainable transportation systems. This study focuses on the design and techno-economic analysis of a grid-connected, on-site hydrogen production HRS powered by wind energy, incorporating various electrolyzer technologies. The selected location for the HRS installation is & Ccedil;anakkale, Turkey, where daily wind speed data has been utilized for performance calculations. The proposed HRS system integrates a wind turbine (WT) with three different electrolyzer technologies: alkaline electrolyzer (AEL), proton exchange membrane electrolyzer (PEMEL), and anion exchange membrane electrolyzer (AEMEL). A comprehensive techno-economic analysis was conducted to evaluate the system's performance, considering factors such as initial capital investment, installation, operation, and replacement costs. The results of the analysis reveal that the levelized cost of hydrogen (LCOH) varies between 9.0 and 18.7 <euro>/kg H2, depending on the type of electrolyzer technology used and the daily hydrogen refueling capacity. Notably, increasing the hydrogen refueling capacity significantly reduces production costs. The minimum LCOH of 9.0 <euro>/kg H2, achieved under a 20-year investment scenario, corresponds to a refueling capacity of 250 kg H2/day when utilizing the AEL-integrated HRS system. The findings underscore the economic feasibility of on-site hydrogen refueling stations powered by wind energy and utilizing AEL, AEMEL, and PEMEL systems. Among the systems analyzed, the AEL-based HRS system demonstrated the highest return on investment (ROI) of 13.02 % and the shortest payback period (PBP) of 7.7 years, highlighting its economic performance. This study provides valuable insights into the integration of renewable energy with hydrogen production infrastructure, emphasizing the potential of wind-powered HRS systems to advance the sustainability and economic viability of hydrogen-based transportation solutions.Article Potential Localization Strategies and Strategic Instruments in Nuclear Power Generation(Pergamon-Elsevier Science Ltd, 2026-01) Ege, AhmetDeploying the right strategies is of paramount importance and plays a key role in technology transfer to achieve localization. Today, around 30 countries are considering or embarking on nuclear power programs. What are the potential strategies for nuclear power technology localization? This study attempts to identify localization strategies in nuclear technology and also to unfold tested approaches, business models, strategic legal and technical instruments. The methodology of the study treats the nuclear industry in a state as a "unit" in which a variation of PEST analysis is implemented to reveal macro-environmental factors followed by SWOT analysis to identify strengths, weaknesses, opportunities and threats of available approaches, business models, legal and technical instruments. Four principal strategies emerge: (1) learning by doing; (2) transfer, adopt, assimilate, develop and export; (3) own or operate with limited transfer; and (4) wait and see. The first two strategies are proposed for the countries willing to launch an ambitious nuclear power program. Own or operate with limited transfer strategy can be deployed in those countries prioritizing security of supply, source of reliable base load generation, general economic development, technological and qualified human resources development. Wait and see strategy is convenient for those countries awaiting progress of new technologies or phased out nuclear power but planning to reintroduce it in the future. Regardless of the strategy selected, wise guiding policies and coherent set of actions must be deployed for a successful assimilation and acquisition of the design,