Precise, economical and sustainable cutting operations are highly desirable in the advanced manufacturing environment. For this aim, the present study investigated the influence of cutting parameters (i.e., the cutting speed (c), feed rate (f), depth of cut (d) and positive rake angle (p)) and sustainable cutting conditions (dry and minimum quantity lubricant (MQL)) on cutting forces (i.e., feed force (Ff), tangential forces (Ft), radial force (Fr) and resultant cutting forces (Fc) and shape deviations (i.e., circularity and cylindricity) of a 6026-T9 aluminum alloy. The type of lubricant and insert used are virgin olive oil and uncoated tungsten carbide tool. Turning experiments were performed on a TAKISAWA TC-1 CNC lathe machine and cutting forces were measured with the help of a Kistler 9257B dynamometer. Shape deviations were evaluated by means of a Tesa Micro-Hite 3D DCC 474 coordinate measuring machine (CMM). Experimental runs were planned based on Taguchi mixture orthogonal array design L16. Analysis of variance (ANOVA) was performed to study the statistical significance of cutting parameters. Taguchi based signal to noise (S/N) ratios are applied for optimization of single response, while for optimization of multiple responses Taguchi based signal to noise (S/N) ratios coupled with multi-objective optimization on the basis of ratio analysis (MOORA) and criteria importance through inter-criteria correlation (CRITIC) are employed. ANOVA results revealed that feed rate, followed by a depth of cut, are the most influencing and contributing factors for all components of cutting forces (Ff, Ft, Fr, and Fc) and shape deviations (circularity and cylindricity). The optimized cutting parameters obtained for multi responses are c = 600 m/min, f = 0.1 mm/rev, d = 1 mm and p = 25°, while for cutting conditions, MQL is optimal.
1 October 2019 in Mehran University Research Journal of Engineering and Technology
EMRS (Emergency Medical Response Service) is the public safety system that is responsible for the initial first aid and transportation of the patient to the hospital. Providing a timely response to any emergency situation is of critical nature and needs to be addressed in the shortest possible time. Decreasing the response to an emergency site and timely pre-hospitalization care location identification and number of emergency response personnel and vehicles are some of the critical elements of EMRS. In this research, a probabilistic model is developed which incorporates the probabilistic response to any emergency situation. The developed model was applied to an actual scenario of the EMRS in the city of Peshawar, Pakistan. The EMRS has 7 locations covering 7 different regions of the city covering more than 1200 square kilometers area. The main purpose of the study is to measure the quality of EMRS on the basis of response time and queue. The study has identified that station 1 and 2 have the highest utilization; 58% each, while station 7 has the lowest utilization at 13.7%. Since the emergency care at the site of incidence is one of the primary responsibilities of the public safety organizations so this study also discusses the average instantaneous utilization of EMRS resources for that region.