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A brief history of Western medicine and healthcare
Published in Emmanuel Tsekleves, Rachel Cooper, Design for Health, 2017
Archaeologists have established that the surgical procedure of trepanning, drilling a hole in the skull to relieve pressure on the brain, was practiced 10,000 years ago when the only tools available were made of sharpened stone. It is fascinating to speculate on the events and ideas that led people to fashion a tool to invade a skull in this way. Whatever the genesis of the practice it is notable that people still undertake it outside mainstream medicine and claim great benefits from a spiritual and wellbeing perspective (Dobson, 2000) as well as an approach to specific illness.
Micro-machining through electrochemical discharge processes: a review
Published in Materials and Manufacturing Processes, 2020
Nitesh Kumar, Niladri Mandal, A. K. Das
Chak and Rao[162] adopted the trepanning method to drill a larger hole having large diameter with a diamond embedded abrasive tool at rotary motion of 20 rpm. They reported that due to insulated nature of the abrasive tool, the interaction between electrolyte and tool was constricted. Hence, generation of side sparks was negligible, which, in turn, enhanced dimensional accuracy. In addition, abrasive electrode enabled to drill deeper hole in comparison to the conventional copper electrode. In another investigation, rotary abrasive electrode showed better machining performance than stationary hollow brass electrode.[188] Moreover, rotary abrasive tool was found to remove the recast layer, formed during the machining. This also contributed to augment the material removal.
A review on strengthening, delamination formation and suppression techniques during drilling of CFRP composites
Published in Cogent Engineering, 2021
Dhruv Rathod, Mihir Rathod, Ronak Patel, S.M. Shahabaz, S. Divakara Shetty, Nagaraja Shetty
Double cone tool geometry gives superior machining of the hole in comparison to twist, brad, and spur drill in CFRP laminates (Zitoune et al., 2013). Stub tool geometry produces a more significant thrust force than the brad-spur tool. A trepanning or U-shape geometry provides the smoothest machining characteristics as they have the lowest extrusion area, which in turn produces the smallest thrust (Mathew et al., 1999). From, Figure 6. thrust force of trepanning drill was 50% lower as in comparison with twist drill. The authors declare that trepanning tool cuts the last fibers without any abrupt, with the momentary increase in feed rate and produced good and acceptable quality of holes.
Analysis of drilling behavior of flax/PP composites
Published in Materials and Manufacturing Processes, 2023
Deepak Kaushik, Inderdeep Singh
Chegdani and Mansori[28] conducted experiments on flax/PP composites to determine how drill tool coatings (Diamond and TiB2 coating) affect the tribology behavior of the composites. In a different investigation, it was claimed that while drilling sisal/PP composites, the employment of a trepanning tool resulted in lower TF than a twist drill, moreover a rise in TF coincided with a rise in FR.[29] Rakesh et al.[30] stated that U-shaped drill bit was more effective to minimize the TF while drilling glass/epoxy composites as compared to trepanning and solid drill bits.