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Minimum quantity lubrication (MQL) is a sustainable method that has been efficiently applied to achieve machinability improvements with various materials in recent years, such as hardened steels, superalloys, soft metals, and composites. This study is the first to focus on the performance evaluation of MQL and dry milling environments with AISI 1040 steel. The tool wear, cutting temperature, and power consumption were considered as the quality responses while cutting speed, feed rate and machining environment are taken as input parameters. The effects of the influential factors are analyzed using analysis of variance (ANOVA) and bar charts. Additionally, Taguchi signal-to-noise (S/N) ratios are utilized in order to determine the optimum parameters for the best quality responses. The results show that the MQL system provides better performance compared to dry milling by reducing the tool wear, cutting temperature, and power consumption. According to the ANOVA results, the cutting environment affects the cutting temperature (37%) and power consumption (94%), while cutting speed has importance effects on the tool wear (74%). A lower cutting speed (100 m/min) and feed rate (0.10 mm/rev) should be selected under MQL conditions to ensure minimum tool wear and power consumption, however, a higher feed rate (0.15 mm/rev) needs to be selected along with a low cutting speed and MQL conditions to ensure better temperatures. A comparative evaluation is carried out on the tool wear, cutting temperature, and power consumption under MQL and dry environments. This investigation is expected to contribute to the current literature, highlighting the superiority of sustainable methods in the milling of industrially important materials.

Drug Delivery Systems (DDS) are frequently operating in a surrounding liquid environment, such as blood in the case of drug-eluting stents or perilymph in the case of cochlear implants. However, there is also a demand for systems with sustained drug release in predominantly dry environments, mostly consisting of ambient air. Examples are the treatment of diseases located in the middle ear or the paranasal sinuses. On the one hand, due to the lack of transportation media, the functionality of a polymer/drug combination for delayed release would be limited in such environments. On the other hand, these environments are generally equipped with mucus membranes. Hence, a somewhat humid surrounding is ensured. In this study, a concept of a hydrogel equipped DDS for drug delivery through the round window membrane is presented, addressing two objectives. First objective is to ensure the drug transport by serving as a diffusion channel. For instance the route to the drug target destination, the round window membrane, can be provided by a hydrogel. The second objective is to ensure the adhesion to the membrane. Two promising approaches are presented in this study: The photo induced immobilisation of PEGDA700, as well as the immobilisation of chitosan on poly(l-lactid) (PLLA). For both approaches PLLA specimen had to be modified with oxygen plasma followed by activation for crosslinking with subsequent immobilisation of the hydrogel. With these methods a layer thickness of at least 5 μm was achieved. All steps were characterized with contact angle measurements. After the immobilization of the hydrogel, the swelling factor, as well as the layer thickness was examined.

This paper investigates the effect of cutting parameters on the surface roughness and cutting force of titanium alloy Ti-6Al-4V ELI when turning using PVD TiAlN coated tool in dry environment. Taguchi L9 orthogonal array design of experiment was used for the turning experiment 2 factors and 3 levels. Turning parameters studied were cutting speed (50, 65, 80 m/min), feed rate (0.08, 0.15, 0.2 mm/rev) and depth of cut 0.5 mm constant. Linear and second order model of the surface roughness and cutting force has been developed in terms of cutting speed and feed. The results show that the feed rate was the most impact factor controlling the cutting force and surface roughness produced. MINITAB 17software was used to develop a linear and second order model of surface roughness and cutting force. Optimum condition was at 66.97 m/min of cutting speed, 0.08 mm/rev of feed rate. Surface roughness 0.57μm and cutting force 54.02 N were obtained at the optimum condition. A good agreement between the experimental and predicted surface roughness and cutting force were observed.