To date, different kinds of biosensing elements have been used effectively for environmental monitoring. Microbial cells seem to be well-suited for this task: they are cheap, adaptable to variable field conditions and give a measurable response to a broad number of chemicals. Among different pollutants, heavy metals are still a major problem for the environment. A reasonable starting point for ...

For the years 1987-1990 160 individual samples of manual metal arc stainless steel (MMA/SS) welding fumes from the breathing zone of welders in four industrial plants were collected. Concentrations of soluble and insoluble chromium (Cr) III and Cr VI compounds as well as of some other welding fume elements (Fe, Mn, Ni, F) were determined. Concentration of welding fumes in the breathing zone ran...

The purpose of this study is to evaluate inter- and intrafractional dose variations resulting from head position deviations for patients treated with the Extend relocatable frame system utilized in hypofractionated Gamma Knife radiosurgery (GKRS). While previous reports characterized the residual setup and intrafraction uncertainties of the system, the dosimetric consequences have not been inve...

abstract to optimal use of available water, irrigation scheduling is important to over scarcity of water resources in arid and semi-arid area. in this research to estimate of maximum allowable deficit (or: management allowed depletion) and irrigation scheduling of fodder mays based on canopy-air temperature difference, a field study was conducted in agricultural faculty of karaj. the lower limi...

background: welding emits harmful rays to the eyes. we evaluate and compare the uv, blue light and ir transmittance characteristics of some currently available welding safety protectors with ansi z87.1 criteria. materials and methods: three type of welding safety protectors (three of each type) have been evaluated for spectral transmittance. one-sample t-test was performed to establish is there...

A design algorithm is derived, for a calculating minimum allowable electrical clearances in alternating and direct current “permissible” equipments, which are authorized to operate in gassy mines and tunnels under Part 18 of Title 30, Code of Federal Regulations [1]. The calculated clearances apply to operations at altitudes ranging up to 12 000 ft (3658 m) above sea level. The minimum allowabl...

DriviNG eGaN® FETs When considering gate drive requirements, the three most important parameters for eGaN FETs are (1) the maximum allowable gate voltage, (2) the gate threshold voltage, and (3) the “body diode” voltage drop. The maximum allowable gate-source voltage for an eGaN FET of 6 V is low in comparison with traditional silicon. Secondly, the gate threshold is also low compared to most p...

DRIVING eGaN® FETS When considering gate drive requirements, the three most important parameters for eGaN FETs are (1) the maximum allowable gate voltage, (2) the gate threshold voltage, and (3) the “body diode” voltage drop. The maximum allowable gate-source voltage for an eGaN FET of 6 V is low in comparison with traditional silicon. Secondly, the gate threshold is also low compared to most p...

Airborne dust bioaerosols, ammonia and formaldehyde levels were determined inside two different (ventilated and unventilated) wood working shops. Airborne dust was found at mean values of 4.3 and 3.01 mg m(-3). These levels were higher than that recommended by Egyptian environmental law [1 mg m(-3) indoor maximum allowable concentration (MAC) for hard wood]. The highest frequency of aerodynamic...

The stability of a high 3 tokamak with a superimposed single helicity stellarator field is investigated in the context of the sharp boundary surface current model. The analysis treats external ideal magnetohydrodynamic modes including both pressure-driven ballooning effects and current-driven kink instabilities. The results show that the addition of an i = 2 field is unfavorable, lowering the a...