Study on Tool Life of Surface Textured Tool in Dry Cutting of Ti-6Al-4V Alloys

Abstract. Surface textured tools were fabricated by laser beam machining. Dry cutting of Ti-6Al-4V alloys was carried out with these surface textured tools and conventional tools for comparison. The cutting temperature, tool flank wear and surface roughness of processed workpiece were measured. The experimental formulas of tool life based on DOT method were developed. Results show that the surface textured tool can reduce the surface roughness of workpiece, and the tool life of surface textured tool is improved by 15 % or so compared with the conventional one

Development and assessment of a water pressure reduction system for lining invert of underwater tunnels

To efficiently reduce the secondary lining external water pressure on underwater tunnels, the feasibility of a novel bottom-up drainage and water pressure reduction system for reducing has been validated by conducting laboratory evaluations. Critical factors of underwater tunnels, including the surrounding environment, lining, bottom drainage system, and other supplementary components have been represented by such system to investigate the drainage mechanism and efficiency of the designed system. The drainage system has been further optimized by analyzing the measured water pressure and flow rate. Experimental results indicate that the designed draining system is feasible for reducing the secondary lining external water pressure in the bottom of tunnels and the water pressure has been reduced significantly with high efficiency. The capacity of the proposed system to control the rapid water inflow in tunnel construction regions can be guaranteed. The factors affecting the performance of the system such as the diameter of the drainage pipe and the inlet water pressure are also discussed

Targeting Oxidative Stress Using Tri-Needle Electrospray Engineered Ganoderma Lucidum Polysaccharide-loaded Porous Yolk-Shell Particles

Chronic lung diseases (e.g. chronic obstructive pulmonary disease and asthma) are associated with oxidative stress and common treatments include various types of inhalation therapies. In this work ganoderma lucidum polysaccharide (GLP), a naturally occurring antioxidant is loaded into porous Poly (ε-caprolactone) (PCL) particles using a single step tri-needle coaxial electrospray process (Tri-needle CES); with a view to develop therapies to combat oxidative stress. Based on the core-shell structure of porous yolk shell particles (YSPs), GLP-loaded YSPs displayed a bi-phasic release pattern. In vitro cell studies indicate GLP-loaded porous YSPs display good biocompatibility and positive attributes towards H2O2-induced oxidative stress in MRC-5 cells and dramatically attenuate intracellular reactive oxygen species (ROS) levels as well as significantly increase cell viability. In vivo inhalation studies indicate that GLP-loaded porous YSPs can be delivered to deep lung tissue and remain deposited for over 48 h and are subsequently removed by natural clearance mechanisms. Based on current findings GLP-loaded porous YSPs are suitable for pulmonary delivery and display good inhalation therapy potential to treat chronic lung diseases