Sharif Digital Repository

The practice of river restoration has grown exponentially over the last several decades. There has been little empirical evaluation of whether restoration projects individually or cumulatively achieve the legally mandated goals of improving the structure and function of rivers. Nutrient reduction through simple methods is the most critical factor. The simplest method, which has minimal financial burden as well as preventing, and reducing the entrance of pollutants into the Chalus River (Mazandaran, in north of Iran), has been selected. The origins of rivers start at a high point and move with a steep. ... 

Vulnerability of water and sewage infrastructure in Kish Island survey versus natural and unnatural threats. It is important to know what to do when crisis or unpredicted event occurs in the Island. Decision makers and master managers of the Island, as the main custodians make suitable and effective reactions and decisions so that the impact of threats is reduced to minimum. According to the threats, there are short term and long term solutions. These solutions can be applied when the Island is encountered with crisis  

A major environmental challenge for wastewater treatment in Iran and other countries is the disposal of excess sludge produced during the biological process. This project has been developing and testing a technology that will help to overcome this challenge in Kish Island wastewater plant. Results demonstrate it can perform highly effective treatment of municipal wastewater while producing low levels of sludge.Applicationofvermifiltrationfor treatment of wastewater sludge using the Eiseniafetida earthworm species. The earthworms’ gut acted as a biofilter whereby there was reduction in the sewage wastewater’s solid and liquid organic and inorganic wastes through ingestion and expelling these... 

From the main factors causing an unpleasant odor can refer to indoles, askatels, mercaptans, some volatile organic compounds, sulfide hydrogen, ammonia, and the number of odor-causing compounds, which are also found in the wastewater facilities and sometimes produce unpleasant odors. Meanwhile, ammonia (Pungent and irritating odor) and sulfide hydrogen (colorless poisonous gas with the odor of rotten eggs) can be presented as major factors in sewage odor.
Several factors are involved in the foul-smelling hydrogen sulfide gas collection system and wastewater treatment. A few of them include numerous sewage pumping stations, selected the appropriate gradient in the collection system,... 

It is well known that the most rigorous method to assess the performance and to predict the seismic demands of a structure subjected to earthquake is nonlinear time history analysis. However, this technique is accompanied by complexities and difficulties in evaluating the seismic demands of structures and requires superior knowledge and skill. As a result, in recent years, nonlinear static analysis has been proposed in performance based design procedures. One of the primary assumptions of nonlinear static procedures is that the behavior of a structure with multiple degrees of freedom (MDOF) subjected to seismic ground motion can be estimated from the response of an oscillator with a single... 

In this study, we will examine persistence of various kinds of seasonally forced epidemiological models and seasonally varying predator-prey models. The results of our study regarding persistence of the models will be shown via basic reproduction number. We will show that, in the framework of our study and under some conditions, persistence is obtained as long as the basic reproduction number is bigger than one. We will also prove that, in the framework of our study and under sufficient conditions, if the basic reproduction number is smaller than one, the species under discussion won’t survive in the predator-prey models, and the disease(s) would go extinct in the epidemiological...