from the perspective of new growth models and new international trade theories, both exports and imports play an important role in a dynamic economy. economically, we cannot merely emphasize on a positive trade balance and we ignore the benefits of imports, and also we cannot advise negative trade balance. but the main concern of policy makers about international trade should be making stabilit...

the first purpose of this study is to present an alternative robust model in order to describe ruminal degradation kinetics of forages and to minimize the fitting problems. for this purpose, the korkmaz-uckardes (ku) model, which has a logarithmic structure, was developed. the second purpose of this study is to estimate, by using the korkmaz-uckardes (ku)model, the parameters tp (the time to pr...

backgrounds and aims: the tehran province was subject to the second highest incidence of fatalities due to traffic accidents in 1390. most studies in this field examine rural traffic accidents, but this study is based on the use of logit models and artificial neural networks to evaluate the factors that affect the severity of accidents within the city of tehran. materials and methods: among the...

regarding the importance of competitive advantages among the transportation systems, improving the costumer’s satisfaction is an important factor in attracting them to these systems. in this research, we focus on the effects of constructing new stations on users and a new mathematical model is proposed for this problem. in the proposed model, two simultaneous effects on customers by constructin...

optimal use of water resources is essential to decrease cost and maximize available water resources. subsurface drip irrigation can increase irrigation and water use efficiency. this irrigation method distributes water into the soil, leaving the surface of the soil dry and decreasing evaporation. in the design of subsurface drip irrigation (sdi) systems, the dimensions of the wetted onion deter...

for non-darcy flow in submerged porous media a one- dimensional mathematical model has been developed. rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. in this research the focus was on the rockfill detention dams in submerged condition. the existence of overtopping rock...

introduction: many organizations, especially service oriented ones, relative to their goals and mission, have a special view towards quality phenomena and its management. methods: this paper analyzes medical service quality in one case the internal section of shaheed rahnemoon hospital based on the basis of gap analysis model and servqual technique. a questionnaire was designed and applied to m...

the steel slag is the main by-product of steel industry. the aim of this study using the steel slag as a low-cost absorbent in order to remove cadmium pollutant from industrial wastewater. some factors that affect the process of cadmium removal by steel slag such as ph, contact time, absorbent dosage and cadmium initial concentration has been studied. standard solution of synthetic wastewater i...

background: previous studies indicate a high incidence of digestive cancers along southern parts of caspian sea including ma­zandaran province. the present study was conducted to further investigate time to occurrence, age distribution and pos­sible risks associated with the incidence time of digestive cancers in the above regions. methods: for this purpose the data of digestive cancer incidenc...

background: the goal was to upgrade and/or uprate the traditional non-contact array by producing few modifications in the configuration of this model in order to maximize light receiving of water from the uv lamp and a better disinfection.  methods: an innovative non-contact model was made with a design based on irradiation of water, which was flowing as two thin waterfalls around a uv lamp in ...