Performance prediction of circular diamond saws from mechanical rock properties in cutting carbonate rocks

Possibility of estimating the sawability of carbonate rocks from some mechanical rock property was evaluated using simple and multiple regression analysis. Hourly Production of circular saws was firstly correlated with rock properties and then, multiple regression analysis was performed. Rock blocks were collected from the factories for laboratory tests, and attempt was made to collect rock samples that were large enough to obtain all of the test specimens of a given rock type from the same piece. Linear, logarithmic, exponential and power curve fitting approximations with the highest correlation coefficient was determined for each regression. Results showed that sawability of carbonate rocks can reliably be predicted from compressive strength, tensile strength using simple regression equations

Analysis of the standard deviation of surface potential fluctuations in MOS interface from DLTS spectra

The surface potential fluctuations can have significant effects on both the magnitude and shape of the measured small-pulse DLTS spectrum. An increase in the dispersion parameter sigma(S) of the surface potential distribution, which is assumed to have a Gaussian form, leads to a reduction in the DLTS signal size, a shift of the peak position and a broadening of the peak shape. A computer program including the exponential temperature dependence of hole capture cross section, sigma(P) = sigma(0) exp(-Delta E-sigma/kT), was developed to analyse temperature-scan DLTS spectra of a MOS structure; in the evaluation procedure sigma(S), sigma(0) and Delta E-sigma are taken as fitting parameters. A bias dependence of sigma(S) has been found and an interpretation of this behaviour has been attempted in the light of random point charges (Brews) and patchwork (Nicollian-Goetzberger) models

Effects of surface potential fluctuations on DLTS of MOS structure

Although the conventional large signal deep-level transient spectroscopy (DLTS) technique is immune to surface potential fluctuations resulting from interface charge inhomogeneities in a MOS structure, in energy resolved, small signal DLTS, the eventual surface potential fluctuation should be considered. In this paper, the effect of the potential fluctuation on the temperature-scan DLTS signal for a given gate bias has been carried out. In fact, this effect shifts the DLTS peak position to lower temperatures and decreases the peak amplitude, leading to an apparent energy position and lower Di, values, respectively

Influence of Annealing Temperature on the Electrical and Optical Properties of CdS Thin Films

CdS thin films were grown onto glass substrates at the substrate temperature of 573 ± 5 K by ultrasonic spray pyrolysis technique. The electrical and optical properties of the films were characterized before and after thermal annealing by using electrical resistivity measurements and UV/VIS spectrophotometer, respectively. Thermal annealing of CdS films was carried out in air ambient at various annealing temperatures from 473 to 673 K. The variation in electrical conductivity and optical parameters such as transmittance, absorbance and energy band gap of the films with thermal annealing temperature was investigated

Admittance analysis of an MIS structure made with PECVD deposited a-SiNx : H thin films

a-SiNx:H thin films, prepared by the PECVD technique, were optically and electrically characterized. The frequency dependent trap admittance derived for the MIS structure in the accumulation gate voltage regime was revised. Based on these results an omitted multiplying factor was included into the derivation. An extension of the tunnelling model in the depletion bias regime was used in comparison with the widely accepted statistical model and finally, the more general feature of the tunnelling-based approaches was discussed

Dielectric studies of tetraethylene glycol-bis(3-methylimidazolium) dichloride (TEGDC) exhibiting large negative dielectric anisotropy

WOS: 000234259900020PubMed ID: 16375433A dielectric anisotropy property of a TEGDC (tetraethylene glycol-bis(3-methylimidazolium) dichloride) is investigated as a function of frequency. TEGDC showed an extremely large negative dielectric anisotropy (-10.95 to -4753.73). Variation of dielectric anisotropy (Delta is an element of) with respect to the spot frequencies reveals that liquid crystal (LC) orientation has an n-type property at low frequencies and as the frequency increases dielectric anisotropy character shifts from negative dielectric anisotropy type (n-type) to positive dielectric anisotropy type (p-type). Consequently, the TEGDC is a liquid crystal with large negative dielectric anisotropy

Report of a case with polymicrobial endocarditis related to multiresistant strains

We present a patient with polymicrobial endocarditis who had been operated on previously for a mycotic aneurysm and was seen at the cardiology clinic because of palpitations related to effort. A transesophageal echocardiogram revealed a 15-mm vegetation on his aortic valve. Staphylococcus epidermidis and Corynebacterium striatum were isolated from the blood cultures. Both strains were multiresistant (susceptible to 3 antibiotics at most) against chemotherapy in vitro. Microbiological eradication was not achieved from blood cultures even after applying antimicrobial therapy with effective antibiotics as determined with an antibiotic susceptibility test. For this reason, the patient underwent valve replacement. He was discharged from hospital in fairly good health. Copyright (C) 2002 S. Karger AG, Basel