Diatoms are microscopic algae with a skeleton called frustule, formed chiefly of silica, and found in almost all aquatic environments climatic conditions. Diatomaceous soils (DSs) originate from frustule sedimentation. In civil works (design construction), the uncommon values obtained DSs not completely understood. There needs to be more knowledge about strength compressibility DSs. The stabili...

The classical penetration theory was corrected and then applied for the semi-theoretical prediction of mass transfer coefficients kLa in a slurry bubble column operated in the homogeneous regime. The gas-liquid contact time was expressed as a ratio of bubble surface to the rate of surface formation. These terms were defined for the case of oblate ellipsoidal bubbles formed under homogeneous flo...

“Silica,” is a term which refers broadly to the mineral compound silicon dioxide (SiO2). Silica can be crystalline or amorphous. Crystalline silica is significantly more hazardous to employees than amorphous silica. In addition to causing the disabling and irreversible lung disease known as silicosis, crystalline silica has been classified as a human carcinogen by the International Agency for R...

Heteroand homopolymers prepared from α-amino acid-N-carboxyanhydrides (NCAs) monomers are widely useful products. The preparation of pure NCA monomers has been extensively studied in the past. Purification methods including repeated crystallizations, extraction, and flash column chromatography have been devised. However, these methods are not easily amendable to large-scale NCA preparations. Th...

A rapid assay procedure was developed for mycotoxin citrinin in corn using liquid-liquid extraction (LLE) cartridges. Ground corn was extracted with methylene chloride and 0.5 N phosphoric acid. The extract was added to an LLE cartridge containing a diatomaceous-earth adsorbant, previously impregnated with sodium bicarbonate solution. After aspiration to dryness, the cartridge was eluted with m...

BACKGROUND Diatomaceous earth (DE) is mined globally and is potentially of occupational respiratory health concern due to the high crystalline silica content in processed material. DE toxicity, in terms of variability related to global source and processing technique, is poorly understood. This study addresses this variability using physicochemical characterisation and in vitro toxicology assay...

This work was a study of the chemical modification of diatomaceous earth (DE) using hydrofluoric acid (HF) solution. Under the experimental conditions investigated, it was found that HF under controlled conditions significantly etched inward into the interior of the existing pore structure in the clay mineral due to its high content of silica, leaving a framework possessing a larger BET surface...

Eight vegetables were pre-treated with and without sa­ ponification, and chromatographed by reversed-phase HPLC. Carote11Oid peaks were identified using seven reference standards. Samples extracts were also chromatographed llsing a mixed magnesia and diatomaceous earth column. Fractions were eluted using stepwise increases in the proportion of acetone in hexane, studied by UV-VIS ab­ sorption s...

Standard activated clotting time (ACT) tests have a poor correlation to bivalirudin levels, leading to uncertainty regarding adequate anticoagulation in percutaneous coronary intervention patients. We tested a Thrombelastograph (TEG) ecarin clotting time (ECT) assay for sensitivity to bivalirudin using blood from 80 patients undergoing interventional cardiology procedures with bivalirudin antic...