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...

Usually, the concentration of minerals is carried out with a set flotation and grinding units. Most modeling strategies for stages have followed separate developmental paths. This paper presents strategy based on using studies to model via an integrated approach. The methodology, which approximate method that allows one study effects circuits, applied copper sulfide mineral appropriate results....

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...

Sicklepod (Cassia obtusifolia) is a weed species that has contaminated soybean and other crops. Although sicklepod continues to be a problem weed, the advent of herbicide-resistant soybeans has reduced the problem somewhat in the last few years. Sicklepod seed contains a gum of commercial interest in addition to protein and fat. An inexpensive process to enrich gum and protein contents of sickl...

This study investigates the grinding of sintered silicon nitride using a SiC wheel with a fine abrasive grit size and dense vitreous bond. The difference of hardness between the green SiC abrasive and sintered Si3N4 workpiece (25.5 vs. 13.7 GPa) is small. Large grinding forces, particularly the specific tangential grinding forces, are observed in SiC grinding of Si3N4. The measured specific gri...

Introduction When the grinding wheel specifications are properly chosen, a SiC grinding wheel performs remarkably well for grinding partially stabilized MgO-ZrO2 ceramics (MgO-PSZ). Rather surprisingly, the highest Gratios are obtained at higher grinding rates for the SiC wheel. This, and the fact that SiC grinding wheels can be readily shaped for use in precision cylindrical form grinding, has...

In the dating of sediments by luminescence methods, to obtain a sample the purest possible as to its mineralogy determines the rest of the analytical procedures. The isolation of the sample minerals is a critical stage due to the impossibility of quantifying the relative contributions to the dose from the different minerals. In this paper we propose a non chemical method to isolate quartz from ...

In the current investigation, we used direct and indirect methods to assess and treat several topographies of aggression that were hypothesized to have separate operant functions in a young boy with severe mental ratardation and pervasive developmental disorder. First, a functional analysis of aggression, using the methods described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994), was...