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The disposal of oily wastewater is a severe environmental problem faced by the metalworking and automobile industries. When released into the environment, oil-contained wastewater severely threatens plant, animal, and human life. Adsorption has emerged as a unique technique, and using natural adsorbents makes it further cheap and more eco-friendly. Removal of both free and emulsified oil from wastewater by using biosorbents was looked upon as an alternative. The present research aims to develop a novel biosorbent from teak (Tectona grandis) leaves suitable for removing oil from wastewater. Batch Sorption studies were carried out by varying pH, sorbent dosage, contact period, mixing speed, and initial oil concentration. The optimum conditions for maximum adsorption efficiency were determined. The results showed that the adsorption of oil onto teak leaf (Tectona grandis) adsorbent follows Freundlich isotherm with a maximum sorption capacity of 10.115 mg/g and a pseudo-second-order kinetic model. The thermodynamic parameter (ΔH = 5033.75 KJ/mol) suggested oil adsorption's spontaneous and endothermic nature onto the teak leaf (Tectona grandis) adsorbent. The best regeneration efficiency was achieved with 0.01 M HCl. [ABSTRACT FROM AUTHOR]

This article questions the cross-cultural ethnographic insight of metalworking as a male craft, commonly performed in male spaces (workshops) away from female members of society, through the analysis of archaeological evidence for the household-based metal production within multi-gendered and multi-generational households and corresponding but rare ethnographic examples. [ABSTRACT FROM AUTHOR]

Difficult-to-cut material, i.e., AISI D2 tool steel, has been widely adopted in metalworking industries to manufacture dies for piercing, blanking, drawing and thread rolling due to its excellent wear resistance and non-deforming properties. This article attempts an experimental study to determine the effect of cryogenic coolant (liquid nitrogen) on the grindability of AISI D2 tool steel as work material and its results are compared with the conventional dry and wet grinding methods. The effects of the cryogenic coolant on force components (i.e., tangential force, Ft and normal force, Fn), specific grinding energy (u), force ratio, surface roughness parameters (Ra and Rz) and microstructure were observed. The comparison results indicate a significant reduction in grindability indices such as 64% and 44% in Ft, 54% and 34% in Fn, 46% and 30% in Ra and 40% and 34% in Rz, respectively under cryogenic grinding at higher downfeed as followed to dry and wet grinding. The grinding performance in Ft, Fn, u and Ra was also improved with an increased delivery pressure of the liquid nitrogen (LN2). From the results, it is concluded that cryogenic coolant offers an influential method to improve grinding performance and surface integrity of AISI D2 tool steel. [ABSTRACT FROM AUTHOR]