A sequence of sixteen photomicrographs of thin sections of unaltered quartz diorite through a zone of deformation to myrmekite-bearing granite near Temecula, California, shows the textural and mineralogical changes that occurred in a quartz diorite as (1) K-metasomatism altered the primary plagioclase crystals to form microcline, myrmekite, quartz-bleb clusters, and recrystallized sodic plagioc...

Two analytical methods, atomic force microscopy and quartz crystal microbalance, were applied to the study of the reaction kinetics occurring between concanavalin A and carboxypeptidase Y, presenting the specific lectin–carbohydrate recognition. The dissociation rate constants for concanavalin A–carboxypeptidase Y complex obtained using both atomic force microscopy and quartz crystal microbalan...

Persistent inflammation and associated excessive oxidative stress have been crucially implicated in quartz-induced pulmonary diseases, including fibrosis and cancer. We have investigated the significance of the particle surface reactivity of respirable quartz dust in relation to the in vivo generation of reactive oxygen and nitrogen species (ROS/RNS) and the associated induction of oxidative st...

The accuracy, reliability and best practises of Tiin-quartz thermobarometry (TitaniQ) in greenschist facies rocks have not been established. To address these issues, we measured Ti concentrations in rutile-bearing samples of moderately deformed, partially recrystallized quartzite and vein quartz from the Hsüehshan range, Taiwan. The spread of Ti concentrations of recrystallized grains in quartz...

During the penultimate glaciation vast areas of the Alps were glaciated, with piedmont glaciers protruding into the foreland. In the easternmost part of the northward draining valleys of the Alps, the glaciers did not reach the foreland, but formed valley glaciers confined by the mountainous terrain. This also applies to the Ybbs valley, where samples for luminescence dating out of glaciofluvia...

The solubilities of the assemblages albite + paragonite + quartz and jadeite + paragonite + quartz in H2O were determined at 500 and 600 !C, 1.0–2.25 GPa, using hydrothermal piston-cylinder methods. The three minerals are isobarically and isothermally invariant in the presence of H2O, so fluid composition is uniquely determined at each pressure and temperature. A phase-bracketing approach was u...

This project was initiated in response to two regulatory developments: (1) an International Agency for Research on Cancer (IARC) ruling to upgrade quartz from a Group 2A to a Group 1 human carcinogen (IARC 1997) and (2) an EPA requirement that communities monitor PM10 (EPA 1986) and a possible modification of EPA guidelines to include PM2.5 (EPA 1996). To determine whether inhalation of large a...

AIM AND OBJECTIVES Use of posts improves the physical properties of endodontically-treated teeth. Different post types are developed such as metal, custom-made, carbon, and quartz. The present study was conducted to evaluate the fracture resistance of glass fiber-reinforced, carbon, and quartz post in endodontically-treated teeth. MATERIALS AND METHODS Forty extracted human maxillary incisor ...

We present a detailed and quantitative examination of the thermodynamics and phase change mechanisms (including amorphization) that occur upon shock wave loading and unloading of silica. We apply DebyeGrüneisen theory to calculate both the Hugoniot of quartz and isentropic release paths. Quartz converts to stishovite between 15 and 46 GPa without undergoing pressure-induced amorphization and pe...

The analysis of an acid-soluble and acid-insoluble fraction of one systematically sampled, partially dolomitized limestone bed is reported. The original lime sediment, composed principally of skeletal remains, pellets, occasional intraclasts, detrital quartz, illite, and muscovite has been modified by the addition of calcite, dolomite, and dickite cements and has been patchily replaced by dolom...