Long-Term Quantification of Stream-Aquifer Exchange in a Variably-Saturated Heterogeneous Environment

the effects of keyword and context methods on pronunciation and receptive/ productive vocabulary of low-intermediate iranian efl learners: short-term and long-term memory in focus

از گذشته تا کنون، تحقیقات بسیاری صورت گرفته است که همگی به گونه ای بر مثمر ثمر بودن استفاده از استراتژی های یادگیری لغت در یک زبان بیگانه اذعان داشته اند. این تحقیق به بررسی تاثیر دو روش مختلف آموزش واژگان انگلیسی (کلیدی و بافتی) بر تلفظ و دانش لغوی فراگیران ایرانی زیر متوسط زبان انگلیسی و بر ماندگاری آن در حافظه می پردازد. به این منظور، تعداد شصت نفر از زبان آموزان ایرانی هشت تا چهارده ساله با...

Streamline-based simulation of virus transport resulting from long term artificial recharge in a heterogeneous aquifer

The likelihood for viruses, protozoan oocysts, and other human pathogens to enter groundwater, and in particular, sensitive or vulnerable water supplies, has increased as the numbers of anthropogenic sources such as septic systems, leaking sewers, animal farming operations, and artificial recharge of treated wastewater have proliferated. In this paper, we utilize a detailed numerical model of g...

Applications of Sensitivity Analysis to Uncertainty Quantification in Variably Saturated Flow

Nonstationary stochastic analysis of steady state flow through variably saturated, heterogeneous media

In this study we develop a first-order, nonstationary stochastic model for steady state, unsaturated flow in randomly heterogeneous media. The model is applicable to the entire domain of a bounded vadose zone, unlike most of the existing stochastic models. Because of its nonstationarity, we solve it by the numerical technique of finite differences, which renders the flexibility in handling diff...

Newton-Krylov-Multigrid Solvers for Large-Scale, Highly Heterogeneous, Variably Saturated Flow Problems

In this paper, we present a class of solvers developed for the parallel solution of Richards' equation, a model used in variably saturated ow simulations. These solvers take advantage of the fast, robust convergence of globalized Newton methods as well as the parallel scalability of multigrid preconditioners. We compare two multigrid methods. The methods di er primarily in their handling of dis...