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Resonant tunneling properties of inverse parabolic multibarrier structures: a non-equilibrium green’s function approach
No full textWe present a theoretical investigation aimed at understanding how external electric fields influence resonant tunneling and quantum transport in inverse parabolic multibarrier semiconductor heterostructures. The main problem addressed is the lack of comprehensive studies describing field-induced localization and miniband modulation in smoothly varying potential profiles. The analysis is carried out using the non-equilibrium Green’s function formalism with the finite element method, which allows accurate determination of transmission spectra, resonant energy levels, and current density-voltage characteristics. Our results highlight the strong dependence of resonant tunneling features on the structural parameters of the system, including the number of barriers, as well as the width of wells and height of barriers. It is found that increasing the number of barriers enhances the complexity of the transmission spectrum, leading to sharper resonant peaks and modified miniband formation. Furthermore, the application of an external electric field introduces a substantial shift in the resonant energy levels and significantly alters the transmission probability. Numerical results indicate that for a field-free structure, unity transmission occurs at specific resonance energies (E 20–250 meV for NB = 2 and 5), while under a high electric field (F = 50 kV/cm), the transmission significantly decreases and resonance peaks vanish due to wave localization. The calculated current–voltage characteristics reveal a pronounced negative differential resistance behavior. As the barrier height increases from 250 meV to 500 meV, the NDR region broadens while the peak-to-valley current ratio decreases. These findings emphasize the tunability of inverse parabolic multibarrier structures and their potential applications in high-frequency nanoelectronic and quantum device technologies
Architectural design and active vibration suppression of sandwich plates using deep neural network-based validation
No full textThis research explores the architectural design and active vibration suppression of three-layer rectangular sandwich plates through a deep neural network (DNN)-based verification framework. The proposed structure has been designed as a sandwich plate subjected to a time-dependent external force and consists of the piezoelectric actuator and sensor face sheets bonded to a zinc oxide-graphene oxide (ZnO-GO) hybrid nanocomposite-reinforced polymer core. The structural mechanics are modeled by the Carrera unified formulation (CUF), allowing a systematic hierarchical representation of displacement fields. The unified formulation produces the governing equations for dynamic response and control via an appropriate discretization strategy and a mixed-interpolation finite element technique. These equations are switched to the Laplace domain for computational efficiency, and the corresponding time-domain solutions are retrieved through the modified Dubner-Abate (MDA) inversion method. A wide range of control schemes has been applied to achieve active vibration suppression, including simple linear damping (SLD) controllers, adaptive band-limited derivative (ABL-D) controllers, hysteresis-based nonlinear (HBN) controllers, fuzzy logic supervisory (FLS) controllers, and hybrid predictive sliding mode (HPSM) controllers. Comparative studies show that the HPSM controller is more robust, has better performance in terms of vibration reduction, and is more stable under different loading and material conditions. In order to ensure the reliability of the control strategies in a more certain way, a DNN-based verification framework is developed to compare the predicted vibration responses with the finite-element-derived control outputs. The outcomes from the deep neural networks (DNNs) show a significant relationship with the predicted structural responses that, in turn, support the credibility of the CUF method and the management system
Silent witness as civic theology: zurab kiknadze and the ethics of public religion in post-soviet Georgia
No full textIn post-Soviet Georgia, the renewed visibility of religion in the public sphere has generated ambivalent effects, fostering both social cohesion and identity-based exclusion. This article focuses on the work I Am the Way by Georgian Orthodox thinker Zurab Kiknadze to explore how a non-instrumental, ethics-based conception of public religion can be sociologically conceptualized. Drawing on a qualitative, hermeneutic-narrative method, the analysis identifies two core motifs in Kiknadze’s thought—“spiritual journey” and “silent witness”—and interprets them through the lenses of public religion theory (Casanova), lived religion paradigms (McGuire, Ammerman), and post-secular debates (Habermas). The findings indicate that Kiknadze understands faith not as a marker of dogmatic or ethno-political belonging but as a practice contributing to ethical continuity and the reconstruction of social trust. Within this framework, “silent witness” is defined as a form of faith grounded in consistency, humility, and action-oriented conviction; it is proposed as a transferable sociological mechanism that supports trust, reconciliation, and inclusive citizenship in transitional societies. Centering on the Georgian case, this article offers a conceptual contribution to rethinking the public role of religion in post-authoritarian contexts within an ethical framework
Morphological structuring of Atlantic bonito (Scombridae: Sarda sarda) stocks in the southern Black Sea revealed by integrative phenotypic analyses
No full textAtlantic bonito ( Sarda sarda ), a commercially important and highly migratory species, has long been managed as a single stock in the Black Sea and adjacent waters. This approach has historically been supported by genetic studies indicating widespread homogeneity. The present study provides an integrative phenotypic assessment of this assumption from a morphological perspective, incorporating: geometric morphometric analysis of body shape, traditional otolith shape indices, elliptical Fourier-based otolith shape analysis, and von Bertalanffy growth modelling. Specimens collected from the Eastern, Middle, and Western Black Sea (∼41–42°N) exhibited consistent morphological structuring, supporting the presence of at least two phenotypically differentiated stocks: one comprising the Eastern–Middle region and the other comprising the Western region. Traditional otolith shape indices failed to detect this structure, whereas elliptical Fourier analysis discriminated the Eastern–Middle phenotypic stock from the Western phenotypic stock. Growth modelling further supported phenotype-based stock differentiation, revealing significant differences in growth trajectories between the Western and Eastern–Middle phenotypic stocks, with no significant separation between the Eastern and Middle regions. This study also provides the first evidence of directional asymmetry in Atlantic bonito otoliths, a potential indicator of environmental stress. These findings advocate for a reassessment of single-stock management strategies and highlight the need for further investigation across broader regions, emphasising the value of integrative phenotypic assessment in identifying and refining management approaches for phenotypically differentiated stocks
Perceptions of the term ‘cancer survivor’ among women with breast cancer: An interpretative phenomenological analysis
No full textPurpose The study aimed to explore the perceptions, feelings, thoughts, and meanings attributed to the term “survivor” by women with breast cancer. Method This qualitative study employed Interpretative Phenomenological Analysis (IPA). Semi-structured interviews were conducted with 23 women with breast cancer who had completed active cancer treatment (surgery, chemotherapy, and/or radiotherapy). Data were transcribed verbatim and analyzed inductively using the IPA approach. Results Three main themes were identified: “the meaning of survivor for me,” “I feel uncomfortable being defined this way,” and “I am more than a survivor.” Most participants reported that the term “survivor” evoked memories of difficult times and ongoing uncertainty regarding the future. Some participants, however, perceived the term positively, associating it with struggle and success. Overall, the term was unfamiliar to participants and was experienced as a labeling expression that overshadowed their sense of self-identity. The women preferred to be referred to by their names or a more positive and respectful term instead of a predefined label. Conclusion The term “cancer survivor” was perceived as negative and uncomfortable by most women in this study. Findings highlight the importance of culturally sensitive language in oncology care. Nurses and other healthcare professionals should consider individualized preferences and avoid imposing labels that may cause emotional discomfort or identity distress
Role of HVAC in building energy consumption: a critical review
No full textThis review critically evaluates the energy performance of diverse HVAC systems, with a focus on their quantified consumption profiles and operational efficiencies across varying climatic zones and building types. Conventional split air conditioning units were observed to have the highest energy demand, reaching up to 18,549.6 kWh month−1 in university buildings, with air conditioning accounting for over 80% of total electricity use. In contrast, variable refrigerant flow (VRF) systems demonstrated superior part-load efficiency, with monthly consumption reduced to 9626.9 kWh and energy performance indices (ENPI) improved by 36.6%. Ground source heat pumps (GSHPs) operating under stable subsurface conditions achieved thermal outputs of 7.0–16.0 kW with COP values ranging from 1.34 to 4.7, while hybrid systems integrating desiccant wheels and evaporative cooling reported cooling capacities between 0.84 and 16.9 kW, and COPs reaching up to 35.2 under optimised conditions. Photovoltaic-assisted systems were capable of offsetting up to 80% of cooling energy demand, equating to approximately 3.5–4.0 kWh/day savings in residential settings. Control strategies such as night purge and adaptive setpoint scheduling yielded energy reductions of 17–26%, and the integration of economisers led to a 25.5% drop in total HVAC consumption. Advanced predictive models incorporating artificial intelligence achieved accuracy levels exceeding R2 = 0.98 across simulations of over 250,000 scenarios. These findings collectively underline the critical importance of selecting context-appropriate HVAC technologies and implementing intelligent, climate-responsive control to achieve substantial reductions in system loads, power input, and operational energy demand, thereby supporting global efforts towards sustainable and low-carbon buildings
Clustering-Fundamental Concepts and Primary Methods
No full textData Mining 13. Hafta Ders Notu Konusu : Clustering-Fundamental Concepts and Primary
Method
The thrombopoietic signature of preeclampsia: diagnostic and monitoring insights from the immature platelet fraction
No full textBackground: Preeclampsia is a major obstetric disorder characterized by platelet activation and dysregulated thrombopoiesis. While conventional platelet indices reflect platelet morphology, the immature platelet fraction (IPF) provides insight into thrombopoietic activity. This study assessed IPF discrimination at presentation and its early post-treatment change in preeclampsia while controlling for potential confounding factors. Methods: In a prospective design, demographic and laboratory parameters—particularly platelet indices—were evaluated in women with preeclampsia and normotensive pregnant controls. Measurements were obtained at diagnosis and repeated 24–48 h after treatment, including initiation of medical treatment or delivery. Logistic regression and ROC analyses were performed, adjusting for age and gestational age. Results: Sixty-four women with preeclampsia and 25 normotensive controls were included; the preeclampsia group was older (31.3 ± 5 vs. 28.4 ± 4 years), and delivery occurred in 73.4%. At diagnosis, IPF, MPV, and PDW were higher, and platelet counts were lower compared with controls. After treatment, IPF decreased markedly (ΔIPF = 3.4; p < 0.001), accompanied by reductions in MPV and PDW, while platelet counts remained unchanged in the preeclampsia group. ΔIPF showed subtype-related differences, being higher in late-onset preeclampsia. Only IPF retained an independent association with preeclampsia (OR = 27.29; p = 0.006), whereas age, platelet count, MPV, PDW, BUN, and CRP were not significant. On ROC analysis, IPF demonstrated strong diagnostic performance (AUC = 0.992; cut-off ≥4%), with 98.4% sensitivity and 100% specificity. Conclusions: Easily measurable as part of a routine complete blood count, IPF may support diagnostic evaluation and clinical monitoring, consistent with its early post-treatment decline and subtype-related patterns
Determining the optimal irrigation activation or agitation techniques for postoperative pain control: A network meta-regression of clinical trials
No full textPostoperative pain after root canal treatment remains a frequent clinical problem despite advances in instruments and irrigants. This Bayesian systematic review and network meta-regression compared seven irrigation activation/agitation techniques-positive pressure, manual dynamic, sonic, ultrasonic, multisonic, negativepressure and laser-activated irrigation-with respect to Day-1 postoperative pain. Electronic searches of PubMed, Cochrane Library, Scopus and Web of Science were conducted up to 10 December 2024; 57 trials (2595 patients) were included qualitatively and 31 contributed to the quantitative network. Pain scores were rescaled to a 0-10 scale and analysed as mean differences, with symptomatic status modelled as an ordinal covariate and treatment rankings summarised using SUCRA values. Laser-activated irrigation (LAI) produced the lowest Day-1 pain and showed a clinically important advantage over manual dynamic irrigation (MDI) exceeding the 1.0-point minimal clinically important difference, while also outperforming positive pressure and ultrasonic irrigation with smaller, statistically but not clinically important effects. Multisonic and negative-pressure irrigation also ranked favourably, whereas MDI consistently showed the highest pain scores and the lowest SUCRA values. Baseline symptomatic status was a strong effect modifier, with symptomatic teeth experiencing substantially higher pain irrespective of technique. Overall CINeMA confidence was low to very low for most contrasts, indicating that these findings should be interpreted cautiously and highlighting the need for larger, better-designed trials with standardised pain-assessment protocols
Numerical analysis of tensile-shear performance in welded plate structures
No full textThe automotive industry extensively uses advanced high-strength steels for structural applications, raising challenges related to the mechanical performance of resistance spot-welded joints. This study numerically investigates the tensile-shear behavior of spot-welded steel plates made of TRIP800, DP450, and DP980 using a three-dimensional finite element approach. The objective is to evaluate the influence of material type and applied load on stress distribution, mechanical response, and safety factors. The results show significant stress concentration near the weld nugget, with a symmetrical distribution in the transverse direction and an asymmetrical pattern along the loading direction. DP450 and TRIP800 exhibit earlier loss of elastic behavior compared to DP980, although all materials maintain adequate safety margins at maximum load levels. These findings underscore the significance of material selection in ensuring the structural integrity of spot-welded automotive components