Aksaray Üniversitesi Kurumsal Akademik Arşivi
DSpace@Aksaray, Aksaray 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 telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
A novel poly(vinyl N-furfuryl-N-benzoylthiourea) and its metal complexes: synthesis, properties, and food packaging applications
(Springer Verlag, 2025) Kurt, Gülşah; Erdem, Nuran; Ünlü, Burhan
4-vinyl-N-furfuryl-N-benzoylthiourea monomer (4VBT1) was successfully polymerized using free radical polymerization conditions with high yields and molecular weights, Mn = 674 kDa with 2.0 molecular weight distribution (PDI). Ag(I), Zn(II) and Cu(II) complexes of this polymer have also been successfully synthesized and characterized. The films of polymer (P4VBT1) and its silver complex (P4VBT1-Ag) were evaluated to determine their food preservation properties. Physicochemical and microbiological analyses of the packaged beef with P4VBT1 and P4VBT1-Ag films were carried out on the 1st, 5th, 10th, and 14th days of the storage process. Moisture levels in P4VBT1 and P4VBT1-Ag stayed stable, and no significant pH difference was detected between the groups at the end of the storage period. The beef’s peroxide in P4VBT1-Ag packaging was lower than others at storage end. During storage, insignificant changes were observed in a* values for group B and b* values for groups A (P4VBT1) and B (P4VBT1-Ag). Throughout the storage period, group B demonstrated the lowest levels of total mesophilic aerobic bacteria (TMAB) and total psychrotrophic aerobic bacteria (TPAB). On day 14, it also had the fewest Escherichia coli, but samples showed no statistical difference. By day ten, P4VBT1 and P4VBT1-Ag packaging showed reduced effectiveness in suppressing Coliform bacteria. Utilizing P4VBT1 and P4VBT1-Ag materials for packaging has led to a slowdown in microbial expansion.
PSO based TCN hybrid optimization for turbulent heat transfer prediction of multiple synthetic jets in crossflow
(Springer Nature, 2025) Akçay, Selma; Buyrukoğlu, Selim; Akdağ, Ünal; Güngör, Bekir
The development of artificial intelligence (AI) models offers significant advantages in laborious, expensive, and long-term experimental and numerical studies. Therefore, AI methods have recently attracted considerable attention in different engineering applications. In the present work, the heat transfer performance of multiple synthetic jets immersed in crossflow on a flat target surface was researched experimentally and estimated with different deep learning models (LSTM, BiLSTM, CNN, GRU, and TCN) and particle swarm optimization (PSO). In the experiments, the effects of the main flow Reynolds number (6000 ≤ Re ≤ 40,000), oscillation amplitude (0.22 ≤ Ao ≤ 0.88), and Womersley number (11 ≤ Wo ≤ 27) on the cooling performance were analyzed. The Nusselt number (Nu), friction factor (f), and thermohydraulic performance (THP) were calculated for different flow and jet parameters. The results showed that for Re = 6000, Wo = 27, and Ao = 0.88, the synthetic jet improved the heat transfer by 2.74 times compared with the steady flow. The THP values increase with increasing synthetic jet parameters, and the highest THP is found 2.06 for Re = 6000, Wo = 27 and Ao = 0.88. Among the deep learning models based on experimental data, the TCN algorithm performed the best when optimized with PSO on data processed by COPULA. Compared with the other deep learning models, the hybrid TCN-PSO model achieves lower MAEs for Nu (5.68561), f (0.00725), and THP (0.0356). This research indicates that integrating deep learning with optimization methods is highly effective for designing models of dynamic thermal systems.
Investigating the effects of carvacrol in isoproterenol-induced myocardial injury: Role of H-FABP and Gal-3/TLR4/MYD88/NF-κB signaling pathway modulation
(Springer International Publishing, 2025) Küçükler, Sefa; Çomaklı, Selim; Özdemir, Selçuk; Değirmençay, Şükrü; Kandemir, Fatih Mehmet; Genç, Aydın; Dalkılınç, Elif; Aydın, Şeyma
This study aimed to investigate the protective effects of carvacrol (CRV) on isoproterenol (ISO)-induced myocardial injury, focusing on its modulation of the Gal-3/TLR4/MYD88/NF-κB pathway. Thirty-five male Sprague Dawley rats were divided into five groups: control, CRV-treated, ISO-induced, and CRV pre-treated with two different doses (ISO + CRV 25 mg/kg and ISO + CRV 50 mg/kg). Cardiac markers, inflammatory cytokines, oxidative stress parameters, antioxidant enzymes, apoptosis, oxidative DNA damage, and endoplasmic reticulum (ER) stress were assessed. The study explored the impact of CRV on galectin-3 and the TLR4/MYD88/NF-κB pathway. ISO-induced myocardial injury was associated with elevated cardiac marker enzymes, inflammatory cytokines, oxidative stress, ERS, and activation of the Gal-3/TLR4/MYD88/NF-κB pathway. CRV treatment significantly attenuated these effects, showcasing its cardioprotective potential. Histopathological examination revealed reduced inflammatory cell infiltration with CRV pre-treatment. Furthermore, CRV significantly reduced oxidative stress parameters, including malondialdehyde (MDA) levels, and increased antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). The study highlighted the protective role of CRV against oxidative DNA damage, as indicated by decreased 8-OHdG levels. Additionally, CRV mitigated ERS by reducing ATF6 and GRP78 expression levels. It was also determined that CRV reduces apoptosis by regulating the expression levels of Bax (Bcl-2-associated X protein) and Bcl-2 (B-cell lymphoma 2), as well as AKT (Protein kinase B) protein levels. This comprehensive understanding underscores CRV's potential as a promising therapeutic agent for managing myocardial injury, providing valuable insights into its broader effects on cardiovascular health.
Assessment of p-wave dispersion and atrial electromechanical delay in patients with non-obstructive coronary artery myocardial ınfarction
(Springer International Publishing, 2025) Keleşoğlu, Şaban; Yılmaz, Yücel; Elçik, Deniz; İnci, Sinan; Gül, Murat; Kalay, Nihat
We investigated p-wave dispersion (Pd) and atrial electromechanical delay (EMD) in patients diagnosed with non-obstructive coronary artery disease and myocardial infarction (MINOCA). Background: The clinical importance and recognition of MINOCA are increasing. However, there is a gap in knowledge regarding the risk of atrial fibrillation in patients with MINOCA. Methods: Forty-three patients with MINOCA (average age 48.69 ± 5.83 years) and thirty-four patients with non-obstructed coronary artery disease (INOCA) (average age 49.82 ± 10.22 years) were enrolled in the study. Echocardiographic studies were conducted in the MINOCA and INOCA groups in the left lateral decubitus position using a medical ultrasound device. Atrial electromechanical coupling (PA) and intra-atrial and interatrial EMD were measured using tissue Doppler echocardiography. Pd was measured using 12-lead electrocardiography. Results: Clinical and demographic characteristics were similar between groups. The maximum P-wave (Pmax) time and Pd values of patients diagnosed with MINOCA were significantly longer than those of patients diagnosed with INOCA (Pmax times: 109.72 ± 7.09 ms and 95.17 ± 7.50 ms, respectively, p < 0.01; Pd: 47.30 ± 8.99 ms and 34.14 ± 11.31 ms, respectively, p < 0.01). Tissue Doppler Imaging (TDI) revealed significantly longer atrial EMD parameters (PA lateral and PA septum) in patients diagnosed with MINOCA than in those diagnosed with INOCA (69.60 ± 8.79 ms and 57.08 ± 11.54 ms, respectively, p < 0.01; 54.83 ± 6.45 ms and 45.35 ± 8.50 ms, respectively, p < 0.01). Conclusion: This study showed that the duration of atrial EMD and Pd was prolonged in patients with MINOCA, suggesting a potential susceptibility to atrial conduction abnormalities.
Pedogenic evidence sheds light on the post-Roman pedo-sedimentological and human history of Tarsus, the Roman capital of CE 60, Cilicia, Mersin, Türkiye
(Elsevier B.V., 2025) Kapur, Selim; Akça, Erhan; Kadir, Selahattin; Previtali, Franco; Billor, Zeki; Zucca, Claudio; Casati, Enrico; Eren, Muhsin; Karagöz, Alptekin
The ancient city of Tarsus is underlying a sediment of 400 cm where the contemporary Tarsus grew. The diffusely stratified layers of the deposited sediment from the Kydnos (Tarsus) river overlying the Roman Road excavation site located in the heart of the modern city. The sediment is laden with technogenic materials. The profile of the stratigraphic layers represents a Pedocomplex (PDC) and its horizons are the Pedomembers (PDMs). All the PDMs were described and sampled for physical, chemical, mineralogical, micromorphological, and thermoluminescense analyses seeking pedogenic evidences. The origin of PDC materials is a fluvial and/or lagoon environment (archaeologically predicted date, about 60 CE, and they are calcareous, high in available P and some are high in total phosphorus contents). They have been partially modified by human activity in a settlement area, thus bringing some historical evidence suggesting that the site was part of the growing city after its abandonment. Thin sections show a vigorous biological degradation of the organic residues in the PDMs along with occasional evidence of soil-forming processes. The preliminary conclusions were extracted from the results obtained through the newly formed hydroxyapatite (Hap) determined by micromorphology, therefore proposing the new suffix π for the WRB soil naming system. Primary, high temperature and clay minerals together with TL analyses of the layers, were conducted to reveal the provenance and weathering phases of the horizons. The seeds recovered from an inhabited layer helped to interpret the food and medicinal habits of the local society and the contemporary presence of the lagoon.
