Background & Aims of the Study: A high nitrate and arsenic concentration in water resources represent a potential risk to the environment and public health. The present work improved a chemo-physically modified activated carbon derived from walnut shells as an adsorbent to improve nitrate and arsenic removal ability from water. Materials & ...

Recently, a mixed integer data envelopment analysis (DEA) model has been proposed to find the most BCC-efficient (or the best) decision making unit (DMU) by Toloo (2012). This paper shows that the model may be infeasible in some cases, and when the model is feasible, it may fail to identify the most efficient DMU, correctly. We develop an improved model to find the most BCC-efficient DMU that r...

In this work the effect of electrolytes on hydrate formation was investigated. To do so, a new model was used in predicting the hydrate formation conditions in presence of both single and mixed electrolyte solutions. The new model is based on the van der Waals - Platteeuw hydrate equation of state. In order to evaluate the values for the activity of water in electrolyte solutions t...

The Competencies of High School Principals in District Four of Mashhad H. Ekrami, M.A. V. Hoshyar, Ph.D. The present study was conducted to identify the competencies of high school principals, propose a competency model, and validate the model. The research was carried out in district four of Mashhad in 2015 and examined two questions: 1.What are the dimensions and components o...