This paper investigates the mechanisms of material removal in dynamic friction polishing of polycrystalline diamond composites through the analysis of polishing-produced debris. The specimens used were PCD compacts composed of diamond and silicon carbide. In order to uncover the debris’ structure, high-resolution transmission electron microscopy (HRTEM), electron diffraction and electron energy...

Non-planarity arising from the chemical mechanical polishing of Cu-oxide damascene results in the exposure field (die-size) being partially out of focus in the subsequent lithography process. The corresponding mechanisms for non-uniformity must be determined and minimized to increase the process yield. In this chapter, contact mechanics models are developed to explain the role of pattern geomet...

The growth of GaN bulk crystals via the HVPE process and the manufacturing of orientation controlled substrates from the GaN crystals are presented. An HVPE process has been produced for growth of bulk GaN on sapphire with an AlN interfacial seed layer. This process has allowed for the production of GaN substrates up to 2 inches in diameter. Due to the stress associated with the growth of GaN o...

This paper investigates the interface temperature rise in polishing a polycrystalline diamond (PCD) surface. First, the Greenwood– Williamson’s statistical asperity model is applied to characterise the surface roughness of a PCD specimen. The result is then used to estimate the contact area and total number of contact asperities under an applied polishing load. The heat generated is taken as th...

OBJECTIVE This study compared the color changes of five novel resin composites polished with two one-step polishing systems when exposed to coffee solution. METHODS The resin composites tested were Filtek Supreme XT, Grandio, CeramX, Premise and Tetric EvoCeram. A total of 150 discs (30/resin composites, 10 x 2 mm) were fabricated. Ten specimens/resin composites cured under Mylar strips serve...

This study sought to assess the effect of different surface finishing and polishing protocols on the surface roughness and bacterial adhesion (S. sanguinis) to polymethyl methacrylates (PMMA). Fifty specimens were divided into 5 groups (n = 10) according to their fabrication method and surface finishing protocol: LP (3 : 1 ratio and laboratory polishing), NF (Nealon technique and finishing), NP...

PURPOSE The aim of this study was to evaluate the efficiency of manual polishing over autoglazed and overglazed porcelain and their effect on plaque accumulation. MATERIALS AND METHODS Thirty-six porcelain discs were fabricated out of which 18 each was subjected for autoglazing and overglazing. Half surface of the discs was left intact; the remaining half was roughened with medium grit diamon...

The effect of different polishing materials on the surface texture and the color change of indirect prosthetic resin composite materials exposed to a staining agent was studied. Six different resin composites were polished using the same procedures and were measured for the gloss. After exposed to a coffee solution, the changes were measured on the color properties. The six different types of r...

2.1 Fiber Endface Conditions Required for PC Connection Figure 1 shows the structure of an 8-fiber MPO connector. To decrease reflection, fiber endfaces in this kind of connector are polished at a gradient of 8° to the fiber cross section. The connector endfaces are held together by the engagement of the guide pins in guide-pin holes. To achieve PC connection in such a connector, it is necessar...

Imperfections in data can arise from many sources. The quality of the data is of prime concern to any task that involves data analysis. It is crucial that we have a good understanding of data imperfections and the effects of various noise handling techniques. We study here a number of noise handling approaches, namely, robust algorithms that are tolerant of some amount of noise in the data, fil...