Hysteresis has been widely recognized in the soil water relationship. In this paper, a detailed review of hysteresis was performed in relation to its models. So far, different models have been suggested to describe hysteresis in the water retention curve (WRC) that could be categorized into two main groups: conceptual and empirical models. The models in the first group are based on the domain t...

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...