Recep Tayyip Erdoğan Üniversitesi Kurumsal Akademik Arşivi
DSpace@RTEÜ, Recep Tayyip Erdoğan Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve yayınların etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Comment on “Current status and comparative risk assessment of microplastic pollution in surface water and sediment from the Black Sea coastline using geospatial analysis” by Özpolatet al.(2026)
(Elsevier, 2026) Gündoğdu, Sedat; Gedik, Kenan; Terzi, Yahya; Öztürk, Rafet Çağrı
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Comparison of transobturator tape and functional electrical stimulation methods in pure stress urinary incontinence
(Elsevier, 2026) Doğan, Osman; Ural, Ülkü Mete; Tekin, Yeşim Bayoğlu; Şentürk, Şenol; Balık, Gülşah; Güven, Seda Güvendağ
Objective: The aim of the current study was to compare the effectiveness of the functional electrical stimulation (FES) and transobturator tape (TOT) methods in the management of pure stress urinary incontinence (SUI). Materials and methods: This clinical study was performed on 58 pure SUI patients. FES and TOT groups were compared in terms of intensity of complaints and changes in quality of life before and after the therapy. The ICIQ-SF and EORTC QLQ-30 questionnaires were applied via interview method. The objective cure rate was evaluated by cough and pad tests. Results: ICIQ-SF scores before and after the treatment and EORTC QLQ-30 scores before the treatment were similar in FES and TOT groups. After treatment, functional and symptomatic outcomes were similar in FES and TOT groups (p = 0.05 and p = 0.115), while general health status outcomes were better in FES group (p = 0.007). There was no significant difference between two groups regarding the objective cure rate. Conclusion: Our results have shown that FES and TOT are similar in their effect on the alleviation of urine leakage. However, FES seems to be superior to TOT for improvement of quality of life. Further studies are needed to compare the efficacy of these two treatment modalities.
Piezoelectrically actuated control of nonlinear vibrations and resonant instabilities in rotating cylindrical structures
(Elsevier, 2026) Owida, Hamza Abu; Mohammad, Suleiman Ibrahim; Vasudevan, Asokan; Mohammad, Anber Abraheem Shlash; Velavan, Geetha; Mabrouk, Abdelkader; Yaylacı, Murat
This research examines how to control axial vibrations using piezoelectric elements and their associated nonlinear vibrational behaviours with regard to rotating cylindrical shells. This will require the use of axial thermal loads in the design model, which utilises the following criteria: (1) As a thin-walled sandwich beam, it consists of a porous functional grading (FG) core and piezoelectric sensor and actuator layers. (2) A thin-walled Rayleigh beam formulation that incorporates geometric nonlinear effects of the von Kármán type to predict varying amplitude of vibration and impact of the piezoelectric elements. (3) The constitutive model of each piezoelectric element, which allows for active control through negative proportional displacement feedback, provides a method for controlling axial vibrations. (4) The governing equations of motion take into account the gyroscopic effects of the rotation and the influence of an interior fluid. The governing equations are derived using Hamilton's principle by retaining all terms up to cubic order and dropping all higher than cubic order terms for the purposes of being analytic. To accomplish this, the Galerkin method is used to convert the resulting partial differential equations (PDEs) into a series of ordinary differential equations (ODEs), and as a group of ODEs, allows the evaluation of a steady state or resonant response using a harmonic trial solution. Investigations into piezoelectric actuation as a means of reducing nonlinear resonant vibrations and preventing dynamic instability from occurring under combined loading conditions that produce thermal, rotational, and fluid loads have been thoroughly conducted. Several parametric analyses reveal how critical rotational speed, thermal gradients, feedback gains, and material gradation are to the conditions that result in the onset of resonant instability and amplitude modulation. The results obtained from these investigations indicate that properly tuned negative displacement proportional feedback can produce a considerable increase in dynamic stability, a reduction in the amplitude of vibration, and a delay of resonance when subjected to multiple types of loading. The results will therefore serve as a useful guideline for designing active vibration control systems for advanced rotating cylindrical systems utilizing multifunctional engineered material architectures.
Flexural strength of bulk-fill resin composites: A Bayesian hierarchical network meta-analysis
(Elsevier, 2026) Hatipoğlu, Ömer; Dinç, Havva Nur; Par, Matej; Pertek Hatipoğlu, Fatma
Objectives: This study aimed to systematically synthesize existing in‑vitro data on clinical variability and mechanical performance differences of bulk‑fill materials. Methods: PubMed, Scopus, and Web of Science were searched up to January 1, 2025. Inclusion criteria was restricted to peer-reviewed in-vitro studies evaluating direct resin composites intended for posterior use. Primary outcome was flexural strength (MPa). Treatment arms were hierarchically specified as composite classes (bulk-fill flowable, bulk-fill sculptable, fiber-reinforced, sonic/heat-activated, chemically activated/alkasite bulk-fill, and conventional sculptable) and their respective sub-brands. Results were synthesized through Bayesian hierarchical model. Results: In total 44 studies (187 arms; 2134 specimens) were analyzed, with specimen numbers per arm ranging from 10 to 140. At class level, conventional sculptables ranked highest, followed by fiber-reinforced and sonic/heat-activated bulk-fills. Bulk-fill flowable and chemically activated/alkasite occupied the lowest ranks. Conventional sculptable demonstrated significant superiority to bulk-fill flowable and exhibited higher flexural strength relative to chemically/alkasite. At brand level; among conventional microhybrids, Grandio and Filtek Z250, among sculptable bulk-fills, Filtek One Bulk Fill Restorative and SonicFill, showed higher mean flexural-strength estimates. In contrast, flowable bulk‑fills such as Surefil SDR Flow and Tetric EvoFlow Bulk Fill tended to show lower values. Filtek One Bulk Fill Restorative demonstrated significantly higher flexural strength compared to SDR Flow and Tetric EvoFlow Bulk Fill. However, confidence in most class- and brand-level comparisons was rated as low or very low, primarily due to heterogeneity, indirectness, and imprecision. Conclusion: While conventional composites generally outperformed bulk-fill composites, some sculptable bulk‑fills exhibited comparable strength. Due to high heterogeneity, current testing and reporting practices provide limited support for clinically meaningful differentiation among bulk-fill composite classes. Significance: Flexural strength data in isolation are insufficient for product selection among bulk-fills; clinical decisions should rely on comprehensive evidence, including multiple in vitro properties and clinical performance data rather than single laboratory rankings.
Volatile constituents of Achillea coarctata and A. maritima
(Elsevier, 2026) Çırak, Cüneyt; Seyis, Fatih; Yayla, Fatih; Kayıkçı, Samim
The phytochemical analyses on the flowering aerial parts resulted in identification of 31 and 34 volatile constituents (VCs) which represent 100% of volatile constituents under the applied analytical conditions and data-processing parameters in Achillea coarctata and Achillea maritima (Asteraceae), respectively. Among the compounds, camphor (43.58%), 1,8-cineole (15.99%) and caryophyllene oxide (14.18%) for A. coarctata and docosane (24.41%), trans-para-2-menthen-1-ol (23.31%) and (Z)-3-hexen-1-yl isobutyrate (22.89%) for A. maritima were detected as major volatile ingredients. The contribution of the present findings to current data on Achillea chemistry and the possible taxonomic significance of the tested volatiles as chemical markers were discussed.
