Browsing by Scopus Q Quality "Q3"

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    Does Pulmonary Function Testing Affect Autonomic Nervous System Activity?
    (GALENOS PUBL HOUSE, 2026-03) Yalçın, Gülay; Erdoğmuş Gülcan, Server; Kavlak, Erdoğan; 308202; 392815
    Objective: The autonomic nervous system (ANS) regulates vital functions such as heart rate (HR) and respiration. Pulmonary function tests (PFTs), which require forced breathing maneuvers, may influence ANS activity, potentially affecting the accuracy of autonomic measurements. This study aimed to investigate the effects of PFT on ANS activity and to assess the reliability of the test order. Material and methods: Forty-eight healthy university students (32 women, 16 men; mean age 19±0.92 years) participated. ANS activity was assessed by heart rate variability (HRV) analysis using the Elite HRV Corsense device. HRV was recorded at rest in a seated position (first measurement), was repeated after a 5-minute rest (second measurement), and was recorded again following PFT performed with a Medwelt SP10 spirometer (third measurement). Results: Comparison of the first and second measurements showed a statistically significant increase only in the root mean square of successive differences (RMSSD) parameter, with no significant changes in other indices. Comparison of the second and third measurements revealed no significant differences in RMSSD or average HR; however, significant changes were observed in the low-frequency (LF) and high-frequency (HF) components and in the LF/HF ratio. Conclusion: Respiratory maneuvers during PFT may temporarily alter ANS activity, particularly affecting parasympathetic-sympathetic balance. The differences between the first and second measurements emphasize the importance of adequate rest periods before HRV assessment. Measurements taken prior to PFT appear to be more reliable for the accurate evaluation of autonomic function.
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    Evaluation of uniform diffraction behavior from circular apertures on opaque and perfectly conductive surfaces using BDW theories
    (Emerald, 2026-02) Altınel, Mustafa; Yalçın, Uğur; 414019
    This study presents a unified and comparative analysis of uniform diffraction fields generated by circular apertures on three canonical surface types: opaque, perfectly electric conductive (PEC) and perfectly magnetic conductive (PMC). This study aims to explore how these boundaries influence field uniformity and angular behavior under identical conditions.Design/methodology/approachThe classical boundary diffraction wave (BDW) theory is applied to the opaque case, and an extended BDW formulation is developed for PEC and PMC surfaces to account for reflective effects. Analytical expressions are derived, and numerical simulations are conducted to examine the impact of aperture size and observation distance.FindingsThe results reveal that PEC and PMC surfaces introduce significant modifications to the angular distribution of the diffracted field, including phase reversals and amplitude oscillations. The extended BDW model successfully predicts these behaviors, particularly near shadow boundaries and axial zones.Research limitations/implicationsThe study is limited to idealized geometries and monochromatic wave excitation. It does not yet consider material losses or complex aperture shapes. Future work may expand this framework to more realistic electromagnetic structures.Practical implicationsThe findings can help electromagnetic engineers optimize antenna design, stealth surfaces and metastructures by offering better control over field uniformity and diffraction behavior across different surface types.Social implicationsWhile the work is theoretical, it supports technological development in sectors like communication, defense and sensing, contributing indirectly to infrastructure reliability and performance.Originality/valueTo the best of the authors' knowledge, this is the first unified parametric study that simultaneously evaluates opaque, PEC and PMC surfaces using classical and extended BDW approaches. It introduces a novel high-frequency framework for comparing uniform diffraction field behavior across distinct boundary conditions.
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    Hungarian Foreign Policy towards the Turkic States: A Motivation for a More Authoritarian‑Leaning Political Model or a Pragmatic Will for Economic Gain?
    (Metropolitan University Prague Press, 2025-04) Hasan, Barış; Topuz, Ali Kılıçarslan; 416023
    This study examines the relationship between the recent discussions that Hungary has moved away from fundamental democratic values and turned into an illiberal democracy and the transformation of Hungarian foreign policy by taking Hungary’s relations with the Turkic states as a case. The dynamics of Hungarian foreign policy towards the Turkic states as part of Hungary’s post-2010 strategy of Eastern Opening are taken as a case study and the influences of these dynamics on perception differences about Hungarian democracy are analysed. It is discussed whether Hungary’s developing political and economic relations with the Turkic states since 2010 involve an emulation of the political models of these states and whether this has an impact on the so-called transformation of Hungarian democracy into an illiberal democracy. It attempts to reveal the extent to which foreign policy developments are decisive for Hungarian domestic politics and, in particular, to identify the triggering factors for Hungary’s rapprochement with the Turkic states. It seeks to answer the question of whether Hungary’s motivation to adapt a more authoritarian -leaning political model or pragmatic economic intentions are more hegemonic in the relationship between Hungary and the Turkic states.
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    Principles of environmentally sustainable agriculture for building resilient and resource-efficient food systems
    (Tübitak, 2025-10) Çakmakçı, Ramazan; Çakmakçı, Songül; Çakmakçı, Muhammet Fatih; 410449
    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 improve resource efficiency and sustainability. The sustainable development of agricultural systems based on resilience and productivity is important to ensure food security. The aim of this review is to compile, describe, and propose future strategies for promising food systems—including transformative innovations and alternative farming techniques—to facilitate the transition toward resilient, resource-efficient, and sustainable agriculture, and to mitigate long-term challenges. It also provides recommendations for future research, sustainability, resilience, and emerging food trends aimed at promoting sustainable food systems and green technologies, protecting ecosystems, resources, and biodiversity, and optimizing waste management and natural resource use. This article focuses on future sustainable food production and security, environmental protection, alternative protein sources, and innovative agricultural techniques; it highlights scientific and technological advancements, emerging research directions, and offers a comprehensive perspective on resilient, resource-efficient, and sustainable food production systems.