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
Synthesis and characterization of a novel membrane based on poly (2-ethyl oxazoline) and poly (propylene) graft copolymer for potential food packaging and medical applications
(American Chemical Society, 2025) Hazer, Baki; Karahaliloğlu, Zeynep; Keleş, Özgür
Cost-effective olefin polymers have been producing several hundred million tons of olefins each year. They have material properties suitable for packaging and biomedical applications. Among them, chlorinated polypropylene (PP-Cl) was functionalized with poly(2-ethyl oxazoline) (PP-polyEtOx) to obtain a biomimetic PP-polyEtOx conjugate polymer material. Poly(2-ethyl oxazoline) is a water-soluble antibacterial and anticancer polymer. The combination of this bioactive polymer with the elastic properties of polypropylene via graft copolymerization provided a potential active food packaging material. Here, the obtained PP-polyEtOx graft copolymer was characterized structurally using 1H NMR, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The water vapor transmission rates of the obtained membranes are better than those of polyethylene terephthalate membrane. Biologic active characterization of the block copolymer was carried out in view of the antibacterial and anticancer properties. The PP-polyEtOx graft copolymers caused a reduction in colony counts for both S. aureus and E. coli compared to the control. The as-synthesized PP-polyEtOx graft copolymers exhibited an inhibition of viability in HT-29 human colon adenocarcinoma cells. © 2025 The Authors. Published by American Chemical Society
Flatness-based finite-horizon multi-UAV formation trajectory planning and directionally aware collision avoidance tracking
(Elsevier Ltd, 2025) Jond, Hossein B.; Beaver, Logan E.; Jiroušek, Martin; Ahmadlou, Naiemeh; Bakırcıoğlu, Veli; Saska, Martin
Optimal collision-free formation control of the unmanned aerial vehicle (UAV) is a challenge. The state-of-the-art optimal control approaches often rely on numerical methods sensitive to initial guesses. This paper presents an innovative collision-free finite-time formation control scheme for multiple UAVs leveraging the differential flatness of the UAV dynamics, eliminating the need for numerical methods. We formulate a finite-time optimal control problem to plan a formation trajectory for feasible initial states. This optimal control problem in formation trajectory planning involves a collective performance index to meet the formation requirements to achieve relative positions and velocity consensus. It is solved by applying Pontryagin's principle. Subsequently, a collision-constrained regulating problem is addressed to ensure collision-free tracking of the planned formation trajectory. The tracking problem incorporates a directionally aware collision avoidance strategy that prioritizes avoiding UAVs in the forward path and relative approach. It assigns lower priority to those on the sides with an oblique relative approach, disregarding UAVs behind and not in the relative approach. The high-fidelity simulation results validate the effectiveness of the proposed control scheme.
Effects of reducing long-term groundwater overdraft in uluova micro-basin
(Springer Science and Business Media Deutschland GmbH, 2025) Şekerci, Kürşat; Tuna, M. Cihat; Doğan, Mustafa Şahin
Recently, groundwater use has increased significantly in response to limited surface water availability in arid and semi-arid regions. This trend has led to increasing concerns about declining groundwater levels and the risk of overdraft. For the above reasons, a hydroeconomic model was developed in this study to evaluate various management scenarios aimed at mitigating the negative impacts of groundwater overdraft. The Uluhem hydroeconomic model focuses on a total of six different water management operations with different physical constraints. The first scenario is a baseline water operation with groundwater pumping (with overdraft), while the next four scenarios cover four different water management operations where groundwater pumping is restricted at different rates (without overdraft). The sixth and final scenario investigates the installation of a solar-powered system to pump water from a nearby surface water reservoir. This last scenario seeks a potential solution to completely eliminate the agricultural water scarcity and associated scarcity costs arising from the first five scenarios. With the Uluhem model, the water deliveries, water scarcity and economic impacts of these six different management scenarios are analyzed. The findings show that the four different scenarios in which groundwater pumping is restricted contribute positively to the groundwater reservoir but increase water scarcity. The solar power plant installation scenario, on the other hand, offers a promising and sustainable solution that not only effectively addresses water scarcity but also eliminates the associated costs. The study investigates the factors contributing to groundwater overdraft and seeks a sustainable solution to current groundwater utilization. The results emphasize the urgent need for effective and sustainable water management strategies to prevent groundwater overdraft. Overall, the study provides valuable insights into groundwater overdraft problems in the Uluova micro-basin and emphasizes the importance of adopting long-term, sustainable groundwater management practices.
Application of Fenton and UV–Fenton Reaction for Resin Wastewater Treatment Detection of Residual H2O2
(Wiley-VCH Verlag, 2025) Özcan, Zeynep; Sönmez, Gamze; Işık, Mustafa
The Fenton and UV–Fenton procedures were utilized in this study to eliminate total organic carbon (TOC) from wastewater generated during actual resin manufacturing. Optimal operating parameter values influencing removal efficiency were identified, including initial H2O2 and Fe2+ concentrations and total reaction time (t). The residual H2O2 concentration was measured using the metavanadate method in all processes. The results indicated that the Fenton process achieved a TOC removal rate of 32.0% at concentrations of 500 mg L−1 for H2O2 and 100 mg L−1 for Fe2+, with a constant pH of 3.78 and a reaction time of 6 h. In the UV–Fenton process, H2O2 concentrations of 500 and 1000 mg L−1 were examined, resulting in 14% and 15% TOC removal efficiencies, respectively. The effect of gradually adding H2O2 on the removal efficiency was also investigated in this study. To do this, the Fenton process started with an initial H2O2 concentration of 250 mg L−1. Once approximately 80% of this amount was consumed, 250 mg L−1 H2O2 was added, and the process continued. A maximum TOC removal of about 71% was achieved by gradually adding H2O2 at a 4000 mg L−1 concentration. On the basis of these findings, the gradual addition of H2O2, as opposed to an initial dose, proved to be a significant and practical method for removing organic matter from wastewater in the Fenton process. © 2025 Wiley-VCH GmbH.
Sustainable utilization of corn waste and their role toward the circular economy
(Elsevier B.V., 2025) Maqsood, Sammra; Navaf, Muhammed; Kumar, Prashant; Yücetepe, Aysun; Trang Thuy, Nguyen Ngoc; Özkan, Gülay; Moreno, Andres; Çapanoğlu, Esra; Khalid, Waseem; Esatbeyoğlu, Tuba
Corn is one of the most widely cultivated cereal crops globally. Its processing generates enormous amounts of agricultural residues, such as corn husk, corn cob, and corn silk. These by-products exhibit immense potential for value addition in the circular economy. However, these are often discarded or underutilized. This review deals with sustainable and innovative approaches for the effective utilization of different corn waste materials, emphasizing their constituents and applications. The advancement in technology, enables the transformation and value addition of corn waste residues into sustainable eco-friendly biomaterials, such as bioplastics, bioethanol, activated carbons, fiber, and bioactive compounds, contributing to the goal of the circular economy. The challenges, policy framework, and future perspectives of the sustainable utilization of corn waste materials are also discussed. This review aims to provide a comprehensive understanding of corn waste valorization strategies and their transformative role in promoting a circular bioeconomy.
