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
Advancing the thermodynamic approach with the predictive model for the freeze-drying of meat
(Frontiers Media SA, 2025) Öztuna Taner, Öznur
The establishment of innovative engineering techniques for meat products is required because of the significant energy requirements associated with freeze-drying of food products. This study is innovative application research on the freeze-drying of meat process and analyses energy efficiency by employing predictive statistical methods. Thermodynamic laws play a crucial role in the thermodynamic analysis of frozen food processes by regulating the essential operations involved in food production. The thermodynamic evaluation of the freeze-drying of meat process was carried out over a total of 40 scenarios covering 24 h (20 scenarios) and 30 h (20 scenarios). The energy efficiency in the 24 h process fluctuated between 38.7 and 43.1% over the 20 scenarios, whereas in the 30 h process, it varied from 36.9 to 41.1% throughout the 20 scenarios. The analysis revealed that the energy efficiency of the 24 h scenarios exceeded that of the 30 h scenarios, suggesting that 24 h is the optimum period for meat drying. This comparative assessment indicates that shortening the drying duration can deliver substantial energy savings without compromising process effectiveness. Future research will look at the application of this technology to enhance food quality and shelf life by applying a comparable freeze-drying technique to meat in various food industries.
Pb2CoMoO6 as a promising energy material: a first-principles perspective
(Springer New York, 2025) Caid, M.; Deligöz, Engin; Rached, D.; Rached, H.; Mansour, H.; Özışık, H.; Rached, Y.
This study presents a detailed first-principles investigation of the structural, elastic, electronic, optical, and thermoelectric properties of the double perovskite Pb2CoMoO6 compound. The calculations were carried out the full-potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT). We evaluated the energetic stability, the Goldschmidt tolerance factor (tG), octahedral factor (µ), and modified tolerance factor (τ), formation energy (ΔHf), cohesive energy (Ecoh), phonon dispersion and mechanical characteristics. The findings confirm that Pb2CoMoO6 crystallizes in a perfectly cubic structure belonging to the Fm-3 m space group. Mechanical analysis indicates high elasticity and strength as evidenced by high mass and Young’s moduli, which indicative the stability of the material. The electronic structure calculations reveal half-metallic ferromagnetic (HMF) behavior, with a spin-up band gap of 1.558 eV along the L-Γ direction under the GGA + U approach. Additionally, the compound exhibits an integer magnetic moment of 3.0 µB per formula unit. Moreover, Pb2CoMoO6 exhibits strong optical absorption in the ultraviolet (UV) spectrum and displays promising thermoelectric behavior, with favorable Seebeck coefficients and a high figure of merit (ZTmax≈1) at room temperature, suggesting potential for applications in spintronic and thermoelectric devices.
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.
