sawdust of the most inexpensive and abundant most engrossing read and the ability to absorb heavy metals from water and wastewater types. on the other hand increased metal hexavalent chromium (cr6 +) in drinking water cause toxicity, and complications from it can be. so the purpose of this research, effects of the dosage absorbent sawduste, equilibrium time, the efficiency of absorption and cal...

background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

abstract major of hydrological systems are very complicated and it is not possible to understand them completely, therefore simplification is necessary to understand or control of a part of the system behavior such as water balance relationships. hydrological models are simple structure of complicated systems in water cycle in the nature. the first goal of a hydrological model is function predi...

A study is presented of the factors affecting the calibration of the mass scale in time-of-flight secondary ion mass spectrometry (TOF-SIMS). At the present time, TOF-SIMS analysts using local calibration procedures achieve a rather poor relative mass accuracy of only 150 ppm for large molecules (647 u) whereas for smaller fragments of <200 u this figure only improves to 60 ppm. The instrumenta...