هاجر طاهری

Human activities in the fields of agriculture, municipal and industry introduce significant amounts of nutrients and organic materials into the rivers and streams resulting in their contamination. Computer models such as Qual2kw are used extensively for water quality management of rivers and streams. The Qual2kw model is a one dimensional, non-uniform, steady water quality model, which has been used by the United State Environmental Protection Bureau and was developed based on the Qual2e model. A water quality model provides a feasible framework by simulating the important physical, chemical and biological processes. Qual2kw is able to simulate a number of components including temperature, pH, carbonaceous biochemical demand, sediment oxygen demand, dissolved oxygen, organic nitrogen, ammonia nitrogen, nitrite and nitrate nitrogen, organic phosphorus, inorganic phosphorus, total nitrogen, total phosphorus, phytoplankton and bottom algae. The main equation which the aforementioned model attempts to solve is the one-dimensional convection-diffusion equation which is applied for each constituent, except for variables related to river-bottom algae. Applications of Qual2kw are found in numerous cited literature. In this paper, based on the model manual, the equations used in the modelling process are described. Also a practical guide for users who want to use this model has been presented.

Demand for water resources in different parts of the world, necessitate the use of wastewater. In using wastewater the soil health must be considered. This study was carried out at Green Space Zob Ahan in the years 1382 to 1385. In this study, the effects of urban and industrial wastewater irrigation on some chemical properties of soil for three years by using five different irrigation treatments were examined. The treatments were as follows: surface irrigation (FI), surface drip irrigation (SDI), subsurface drip irrigation in 30 cm depth (SDI30), Sub surface drip irrigation in 60 cm depth (SDI60) and irrigation procedures babbler (BI). At the end of the experiments, solid samples were taken of the soil of zero to 30, 30 to 60 and 60 to 90 cm depth in order to measure the heavy metal. Lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn) and manganese (Mn) were measured by using atomic absorption in soil samples. Results showed that the density of heavy metals in urban and industrial wastewater is in an allowable range and heavy elements of soil are not limiting factor. And also concentration of heavy metals was higher in the zone of wastewater injection and as whole treatments SDI60 and BI respectively had the highest and least amounts of heavy metals.

• Evidence based practice is an approach to clinical practice which emphasizes the use of best clinical researches as a component of clinical decision making. The aim of this study was to determine the percentage of current clinical decision making and disease management which is based and supported by high-level evidence in an educational hospital located in Isfahan, Iran. A cross-sectional study was carried on 103 patients who were admitted during one month to seven Internal medicine wards in Alzahra hospital. For each patient, the primary diagnosis and primary treatment were recorded. Evidence based resources were then searched for randomized controlled trials (RCT’s), systematic reviews and clinical practice guidelines to find the best research evidence that the treatments were effective. The main outcome measure was the level of evidence which supports the primary intervention for the primary diagnosis of each patient. Level I evidence (at least one randomized trial) supported the primary intervention used in 68.9% of internal admissions and level II evidence (convincing non-experimental evidence) supported the primary intervention in 31.1% of admissions. None of patients received intervention with level III supporting evidence. Most patients had received high level supported interventions. It seems that we should repeat this study in other wards. Also it may be recommended to design some educational evidence based practice for non academic physicians.