An environmentally benign, fast and convenient protocol has been developed for the Michael addition of 1,3-dicarbonyl compounds to β-nitroalkenes in good to excellent yields by a grinding method under catalyst- and solvent-free conditions.

The grinding force is a key parameter in the grinding process, which is closely associated with the grinding mechanism of engineering ceramics, microstructure and properties of ceramic materials, and the selection of grinding parameters. Meanwhile, it is also a key indicator to assess the grindability of a material. The grinding force is a crucial parameter to reflect the grinding process, whic...

This article discusses the recent developments in grinding of advanced materials. Eighty-four journal papers published recently are briefly introduced. The topics are advances in grinding of brittle materials, grinding of silicon, dressing/truing of grinding wheels, grinding fluids, grinding of mirrors and vibration-assisted grinding, measuring/ monitoring of grinding, optimization of grinding,...

A highly efficient, chemoselective synthesis of a library of polysubstituted pyrroles and tetrahydropyridines has been achieved through the one-pot, multicomponent reactions of ethyl (E)-3-(aryl/alkyl amino) acrylates, 2,2-dihydroxy-1-arylethan-1-ones, and malononitrile under solvent- and catalyst-free grinding conditions. The selective formation of pyrrole or tetrahydropyridines relied on subs...

This paper investigates the grinding performance of epoxy matrix composites reinforced by unidirectional carbon fibres, using an alumina grinding wheel. Emphasis was placed on understanding the effect of fibre orientations and grinding depths on the grinding force and surface integrity, and on understanding the grinding mechanisms, with a comparison to orthogonal cutting. It was found that grea...

Off-round grinding performed on CNC cylindrical grinding is a relatively new process. This paper takes a systems approach and discusses the various inputs and outputs and highlights the potential problems that production engineers face in implementing this new process. The effect of the inputs to the off-round grinding process such as the grinding machine, wheel, grinding fluid and the workpiec...

This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (LavaTM and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was con...

Automation of grinding of metalcastings is desirable for many reasons. The major reasons are dangerous working conditions, low productivity, and inconsistency in human operations. As an approach to the automating grinding process, a gantrydriven grinding machine is proposed to manipulate an industrial hand grinder and control the grinding force applied to the work piece. To increase the materia...

This paper presents results obtained from the grinding of aluminium-based metal matrix composites reinforced with either aluminium oxide (Al2O3) or silicon carbide (SiC) particles using grinding wheels made of SiC in a vitrified matrix or diamond in a resin-bonded matrix. The study used grinding speeds of 1100–2200 m min , a grinding depth of 15 m for rough grinding and 0.1–1 m for fine grindin...

Study on ambient and cryogenic grinding was performed to test the novelty of cryogenic grinding and pin point the drawbacks of ambient grinding. Comparative study had shown that ambient grinding need more power (8.92%) and specific energy (14.5%) than cryogenic grinding. Particle size analysis had shown that cryogenic grinding produced coarser particles. Comparative study of energy law constant...