objective: in this study, the effect of bur cutting efficacy was evaluated on microleakage of class v composite restorations with two adhesive systems. materials and methods: class v cavities were produced on sound extracted human teeth, which had been assigned randomly to one of six groups (n=15) as follows: groups 1 and 6 were prepared using used rough diamond bur; group 2 and 5 were prepared...

This report presents a simplified surface reaction mechanism for the Chemical Vapor Deposition (CVD) of diamond thin films. The mechanism also accounts for formation of point defects in the diamond lattice, an alternate, undesirable reaction pathway. Both methyl radicals and atomic carbon are considered as growth precursors. While not rigorous in all its mechanistic details, the mechanism is us...

A computably enumerable (c.e.) Turing degree is a diamond base if and only if it is the bottom of a diamond of c.e. degrees with top 0′. Cooper and Li [3] showed that no low2 c.e. degree can bound a diamond bases. In the present paper, we show that there exists a nonlow2 c.e. degree which does not bound a diamond base. Thus, we refute an attractive natural attempt to define the jump class low2.

Diamond was discovered to be carbon in 1796, and it took more than 150 years from that time until a method of diamond synthesis was invented. The secret was pursued by many scientists but not unlocked until the 1950s, when diamond was synthesized almost simultaneously by Swedish and American researchers. Pressures of over 55,000 atmospheres and 1400C, plus molten iron to facilitate the change f...

BACKGROUND This study compared different diamond burs and different water flow rates on the cutting efficiency of sectioning through lithium disilicate glass ceramic. METHODS The authors used a standardized cutting regimen with 4 brands of diamond burs to section through lithium disilicate glass ceramic blocks. Twelve diamonds of each brand cut through the blocks in randomized order. In the f...

A formal implementation of the Fowler-Nodheim equation to emission characteristics of diamond coated cold cathodes gives values of the work function which depend on surface curvature of the coating, thus making it incorrect. Experiments with diamond coated Si tips having different coating radii have shown, that their emissivity depends on the radius of the Si tip rather than on the radius of th...

The scheme of motion estimation is introduced to exploit the redundancy between continuous frames of 3D medical image sets in this paper. The proposed scheme is based on inter-frame motion estimation of inverse diamond search algorithm. The residual images are encoded by the Huffman encoder. The test images include five sets of the heart and two sets of the brain MRI images. The average compres...

High-quality single crystal diamond has been used to demonstrate the RF performance of hydrogenterminated diamond field effect transistors of varying gate lengths; this includes the first data on a sub100nm diamond transistor. The RF performance for 220nm, 120nm and 50nm gate length transistors was extracted and a cut-off frequency of 55 GHz was measured for the 50nm device. This is the highest...

As a step towards resolving the genesis of inclusions in diamonds, a new technique is presented. This technique combines cathodoluminescence (CL) and electron backscatter diffraction (EBSD) using a focused ion beam– scanning electron microscope (FIB–SEM) instrument with the aim of determining, in detail, the three-dimensional diamond zonation adjacent to a diamond inclusion. EBSD reveals that m...

A closed system hot filament chemical vapor deposition (CVD) reactor has been used to deposit diamond films on silicon substrates. A fixed charge of hydrogen gas is fed into the deposition system until the desired deposition pressure level is reached. A solid graphite cylindrical rod held above the tungsten filament was the carbon source. System parameters for diamond film growth have been dete...