For any type of combustible dust, several important explosive parameters must be taken into account when designing and using protection systems: namely the ease with which dust clouds ignite their burning rate, maximum explosion pressure, pressure rise speed. explosion. The accuracy results obtained necessary for design use systems depends on a number factors but also application test method (s...

background: agate is a hard silica stone with bands of various colors, which is used in jewelry. the agate grinding workers are exposed to silica dust. objective: to determine the prevalence of respiratory diseases in agate grinding workers and the associated factors. methods: in this cross-sectional study, 170 agate grinding workers from mashhad, northeastern iran, were examined. medical and o...

As a result of irradiation by slow hydrogen and argon ions of saccharose, humic films having a fractal nature were produced. The use of hydrogen ions simulated roughly the interaction of lowenergy solar wind protons with interplanetary dust grains which, in addition to organic and mineral dust, may include clumps of viable bacteria. The type of film generated by this experimental procedure coul...

Venting devices are commonly used to try to reduce the damage caused by any dust explosion that may occur in silo systems. In North America and Europe the sizing of these vent areas is governed by standards NFPA 68 and EN 14491 respectively, both of which have recently come into force. The aim of the present work was to compare these standards in terms of the cost of protecting against dust exp...

This study investigated occupational exposure to silica dust of 48 workers in stone cutting, glass making, ceramic, and sand blasting plants in the north of Iran. Samples were collected from the breathing zone using a personal sampling pump and a size-selective cyclone. Sample filters and blanks were analysed using infrared spectroscopy. The mean sampling period was 4.83 h. Mean exposure of wor...

A multicompartmental model for the kinetics of dust retention in the pulmonary region of the lung and in the tracheobronchial lymph nodes has been developed. The model reflects the following ideas concerning the basic features of this process: (1) penetration into the pulmonary interstitium and translocation to the lymph nodes are possible for non-phagocytized particles only; (2) these processe...

background: composition of dust in the air due to contact with human via inhalation, ingestion and skin absorption will have a large impact on public health. in the learning environments such as universities, many people spend most of their day in contact with the dust. the purpose of this study was to evaluate the concentration of heavy metals lead, chromium and copper in the training space of...