Kilroe-Smith and Breyer (1963) reported that in the early stages of silicosis in guinea-pigs exposed to the inhalation of quartz dust, before the formation of collagen, there were increases in the specific activities of the complete succinate oxidase system and succinate dehydrogenase. The effects on these enzymes of quartz dust have now been compared with the effects of the fibrogenically 'ine...

Carbon nanotubes (CNTs) were deposited on various substrates namely untreated silicon and quartz, Fe-deposited silicon and quartz, HF-treated silicon, silicon nitride-deposited silicon, copper foil, and stainless steel mesh using thermal chemical vapor deposition technique. The optimum parameters for the growth and the microstructure of the synthesized CNTs on these substrates are described. Th...

In the configuration of an electrode-separated piezoelectric sensor (ESPS), the quartz crystal surface is in a direct contact with the liquid phase. The quartz surface can be hydrated to form silanol groups, which can adsorb nonionic surfactant Triton X-100 through hydrogen-bonding interaction between the silanol OH group and the ether oxygen atoms. The adsorption process of Triton X-100 on qua...

The variability associated with Sibudu's Howiesons Poort Industry highlights the unpredictable trajectory of technology in the Middle Stone Age. We reach this conclusion through a study of the technology on quartz from one of the Howiesons Poort layers (Grey Sand) from Sibudu rock shelter. Quartz bifacial technology has previously been described at the site, but this new in-depth study of the q...

A b s t r a c t A n X-ray diffraction method for determining quartz in sediments is described which is both rapid and precise, with a coefficient of variation of 1.9 per cent. Samples are ignited at 950~ prior to X-ray analysis. This removes the interference of clay peaks, increases the relative intensity of the quartz peaks and reduces the initial matrix variation of samples. The peak area rat...

OpenGL is getting used more in window system as a way of improving performance and enabling new functionality. Examples of two systems using different approaches of how OpenGL is being used are Quartz Extreme and Fresco. Quartz Extreme uses window composition which assures fast redisplay and Fresco on the other hand uses a structured graphics approach which utilises OpenGL on a much lower level...

The available shock-wave data for solid .a quartz in the stishovite pressure regime are reduced to a 25øC isotherm and an adiabat, centered at standard conditions, using recent standard density, enthalpy, and coefficient of thermal expansion data. The calculated isothermal bulk modulus, 3 Mb, as determined from the Bireh-Murnaghan equation, depends critically on the value of (dK/dP)•, at zero p...

Two biodegradable quaternary ammonium salts were synthesized and used as cationic collectors in processing iron ores by froth flotation. The flotation behaviors of iron minerals with the new biodegradable quaternary ammonium collectors were investigated by micro-flotation tests of quartz (SiO2) and magnetite (Fe3O4). It was observed that the new biodegradable collectors were effective in separa...

In the preceding paper of this series (1) it was shown that carbon particles are ingested by rat leucocytes three or four times as readily as quartz particles of approximately the same size. Variations were found, however, in this ratio between the rates of ingestion of carbon and quartz during the course of a single experiment which suggested that significant variations might be produced by va...

The signature scheme Quartz is based on a trapdoor function G belonging to a family called HFEv-. It has two independent security parameters, and we claim that if d is big enough, no better method to compute an inverse of G than the exhaustive search is known. Such a (quite strong) assumption, allows to view Quartz as a general construction, that transforms a trapdoor function into a short sign...