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Yayın Investigation of ultrasonic vibration assisted orthogonal turning under dry and minimum quantity lubrication conditions and performing sustainability analyses(Elsevier Sci Ltd, 2024) Duman, Erkin; Yapan, Yusuf Furkan; Salvi, Harsh; Sofuoglu, Mehmet Alper; Khanna, Navneet; Uysal, AlperRecently, increasing pressure on industries to innovate and adopt sustainable techniques has sparked investigations into machining strategies that have minimal carbon emissions, minimal energy consumption by machine tools, and low machining costs. The primary aim of this paper is to identify the machining conditions that can fulfill the criteria of clean production and sustainable chip forming for low-alloy steel which is extensively used in the many industrial field. To achieve this goal, experiments were done under both dry and Minimum Quantity Lubrication (MQL) conditions, aided by ultrasonic vibration assisted hybrid machining conditions at various cutting speeds (100 and 140 m/min) and uncut chip thicknesses (0.1, 0.14, and 0.18 mm). The study was conducted in two stages. In the first part, machining experiments were performed afterward, cutting forces, cutting temperature, chip morphology, surface roughness, and texture were examined. The second part of this study evaluates the sustainability of various machining parameters and cutting environments. The analysis of economic feasibility or rather the total machining costs were estimated by evaluating the costs incurred due to investment of machine tools, lubricant/coolant delivery systems and ultrasonic vibration system costs, waste processing and management costs, cutting tool and labor costs, cost of cutting fluid and energy consumed. On the other hand, environmental viability was evaluated by estimating the carbon emissions (CE) due to the power consumed, material utilization (i.e., the cutting tool and cutting fluid), and the waste processing and management (i.e., disposal of cutting tool, cutting fluid and chip recycling). Results indicate that both dry and MQL ultrasonic-assisted machining processes resulted in improved chip breakability, and produced shortcomma chips. Additionally, it reduced cutting force by 28% and the cutting temperature was lowered by 30 %. Besides, Minimum Quantity Lubrication + Ultrasonic Vibration Assisted Machining (MQL + UVAM) hybrid method prevented surface defects and reduced average surface roughness by 24%-35% compared to dry conditions. While utilizing the MQL + UVAM method, the overall machining cost decreased in the range of about 20-30 % as compared to dry and dry + UVAM conditions. From an environmental standpoint, the MQL + UVAM hybrid machining process was found to be a significant contribution to the overall CE due to use of cutting fluids and increased machine tool utilization. This paper contributed to the understanding of sustainability and cleaner production to mitigate CO2 emissions by using the MQL + UVAM hybrid method.Yayın Synergistic effects of ultrasonic vibration and nanofluid-MQL on surface integrity in sustainable machining of Ti-6Al-7Nb alloy(Elsevier Ltd, 2025) Duman, Erkin; Yapan, Yusuf Furkan; Uysal, AlperRecent trends in the biomedical industry emphasize improving the surface properties of materials for better biocompatibility. Consequently, various surface modification techniques, including machining, are used on titanium bioimplants. This study investigates the impact of sustainable machining on the surface integrity of the Ti-6Al-7Nb biomedical alloy under various cutting conditions including conventional dry cutting, minimum quantity lubrication (MQL), graphene nanofluid-based MQL (N-MQL), and ultrasonic vibration-assisted machining (UVA), encompassing UVA-DRY, UVA-MQL, and UVA-N-MQL. The focus is to analyze the relationship between machining performance and surface integrity. Machining experiments first evaluated cutting forces, cutting temperatures, and chip morphology. Then, surface roughness, texture, microstructural changes, microhardness, and phase transformation were examined to assess surface integrity. The findings reveal that the UVA-N-MQL significantly reduces cutting forces (by up to 6 % for main cutting force and 10.4 % for thrust force) and cutting temperatures (by up to 29 % compared to dry cutting), while enhancing chip breakability. These outcomes stem from the synergistic interaction between the ultrasonic softening effect induced by high-frequency tool oscillations and the enhanced coolant/lubricant penetration enabled by N-MQL lubrication. Additionally, surface roughness was minimized by up to 57 % with UVA-MQL, resulting in the smoothest surface finish. Microstructure analysis also indicated that dry cutting produced the deepest deformation layer (29.5 µm), while UVA-N-MQL achieved the shallowest affected zone (9.5 µm). Subsurface hardness exhibited a notable increase within a depth range of 60–80 µm, with dry cutting demonstrating the most significant work hardening (a 12 % increase), in contrast to UVA-MQL, which experienced the least. Phase transformation analysis revealed a significant increase in the β phase ratio due to machining, with conventional turning exhibiting higher transformation than UVA machining. The UVA-N-MQL method resulted in 10.4 % less phase transformation compared to conventional dry cutting.Yayın The effect of a students led caregiving support program on depression, sleep quality and quality of life of the caregivers and patients with stroke(Taylor & Francis Ltd, 2025) Doğru Hüzmeli, Esra; Güntel, Murat; Tambağ, Hatice; Kutlu, Yakup; Lekesiz, Eren; Dağlı, Okan; Baytak, Sevgi; Gökçek, Özden; Demetgül, Özcan; Duman, Taşkın; Uysal, Alper; Auais, MohammadPurposeWe aimed to provide care support to stroke patients and their caregivers and investigate this support's impact on the psychosocial characteristics of patients', caregivers', and volunteer students' depression, quality of life, and sleep quality.Material/MethodsVolunteer students received caregiving training and provided support to caregivers at patients' homes. Caregivers received care support through the project for four sessions, once a week. Depression levels were assessed using the Beck Depression Scale, quality of life with RAND-36, sleep quality with the Pittsburgh Sleep Quality Index.ResultsThe study included 15 patients after stroke, 15 caregivers, and a total of 30 students participated in delivering the intervention. We observed that physical function (d = 0.52) and social function (d = 0.67) showed significant improvements with moderate effect sizes in caregivers. In patients, Energy/Vitality (d = 0.86) showed a significant and large effect size, and pain reduction (d = 0.78) demonstrated a significant, moderate effect size. For students, Emotional Role Difficulty had a significant improvement with a moderate effect size.ConclusionsOverall, the findings suggest that the project led to meaningful benefits for all involved, particularly in enhancing quality of life parameters. It was found that all participants were extremely satisfied with the study and thought that it should be expanded.Yayın Ultrasonic vibration-assisted machining with minimum quantity lubrication for aerospace materials(Springer Nature, 2024) Duman, Erkin; Yapan, Yusuf Furkan; Uysal, Alper; Sofuoğlu, Mehmet AlperThis chapter offers an insightful examination of the advancements in machining aerospace materials, focusing on ultrasonic vibration-assisted (UVA) machining and minimum quantity lubrication (MQL) techniques. It begins with an introduction to the unique challenges associated with machining these advanced materials and how UVA machining and MQL have emerged as innovative solutions to address these challenges. The chapter then systematically explores the effects of these techniques on various aspects of the machining process. It discusses how UVA machining and MQL influence cutting forces, leading to potential reductions in tool wear and energy consumption. The impact on surface quality is also examined, highlighting improvements in terms of both physical appearance and structural integrity. The chapter further discusses the changes in chip morphologies that result from employing UVA machining and MQL, which are crucial for understanding the material removal mechanisms and overall machining efficiency. Finally, it addresses the implications of these techniques on tool wear, emphasizing their potential to extend tool life and maintain machining accuracy. This chapter not only synthesizes current research but also provides practical insights for industry professionals seeking to optimize machining processes for aerospace materials.
