Investigation of heat assisted high speed end milling of soda lime glass for surface generation

Brittle materials like soda lime glass can be machined in ductile mode under controlled machining conditions (feed rate, depth of cut, small tool edge radius) using high speed to generate a desired surface finish. The heat generated in high speed machining tends to promote ductile machining. In this paper, heat assisted high speed end milling is investigated to explore machinability of the soda lime glass. The heat assisted machining thus generates low surface finish on the machined workpiece. The heat assisted high speed end milling of soda lime was carried out using uncoated 2 flute carbide end mill at a constant depth of cut 25 μm, while the spindle speed and feed rate were varied from 30,000 to 50,000 rpm and 45 to 75 mm/min, respectively. The applied temperature was varied from 200 °C to 300 °C. The observations of machined surface were done on Surf-test (SV-514) and Scanning Electron microscope (SEM). A quadratic model for roughness (Ra) was developed using Central Composite Design of experiment. The optimum Ra, 0.10 μm was achieved at 49,570 rpm, 58 mm/min feed rate and heating temperature at 238°C. It is found that cutting speed has the greatest influence on the surface roughness value, followed by feed rate and heating temperature

Success Factors for Community Health Workers in Implementing an Integrated Group-Based Child Development Intervention in Rural Bangladesh.

Community Health Workers (CHWs) can effectively implement maternal and child health interventions, but there is paucity of evidence on how to integrate child stimulation into these interventions, and their delivery at scale. In rural Bangladesh, CHWs implemented an intervention integrating psychosocial stimulation, nutrition, maternal mental health, water, sanitation, hygiene (WASH) and lead exposure prevention. In each of 16 intervention villages, one CHW worked with 20 households. CHWs bi-weekly held group meetings or alternated group meetings and home visits with pregnant women and lactating mothers. We assessed the intervention through five focus groups, four interviews and one group discussion with CHWs and their supervisors to explore success factors of implementation. CHWs' training, one-on-one supervision and introduction by staff to their own community, and adoption of tablet computers as job aids, enabled successful session delivery to convey behavioral recommendations. CHWs reported difficulties delivering session due to the complexity of behavioral recommendations and struggled with age-specific intervention material. Young children's attendance in group sessions generated distractions that undermined content delivery. We identified ways to minimize the difficulties to strengthen intervention-delivery during implementation, and scale-up. Iterative revisions of similarly integrated interventions based on qualitative evaluation findings could be delivered feasibly by CHWs and allow for implementation at scale

Comparative Assessment and Merit Appraisal of Thermally Assisted Machining Techniques for Improving Machinability of Titanium Alloys

Computer vision is presently a very relevant and important tool in both industrial manufacturing and mobile robots. As human vision is the most relevant sense to feed the brain with environmental information for decision making, computer-vision is nowadays becoming the main artificial sensor in the domains of industrial quality assurance and trajectory control of mobile robots

Numerical studies of frictional responses when cutting hybrid CFRP/Ti composite

In manufacturing sectors, machining hybrid CFRP/Ti is usually an extremely challenging task due to the disparate natures of each stacked constituent involved and their respectively poor machinability. The current research focus of hybrid CFRP/Ti cutting was primarily made via the experimental studies, which exhibited high cost and time consuming. In this paper, a new contribution was provided to study the key frictional responses dominating the bi-material machining via the numerical approach. To this aim, a multi-physical model was developed by implementing different constitutive laws and damage criteria to construct the anisotropic machinability of the stacked composite. The interrelated effects of the multi-toolwork frictional behavior on hybrid CFRP/Ti cutting were precisely investigated with respect to the specific cutting energy consumption, machined surface morphology, and affected subsurface damage. A special focus was made to clarify the cutting sequence’s influences on the hybrid cutting operation. The numerical results highlighted the reasonable CFRP→Ti cutting sequence for hybrid composite machining and the pivotal role of multi-tool-work interaction in affecting the frictional responses induced by cutting