فهرست مطالب زهرا مولائی

Yarrow is a member of the Asteraceae family, utilized extensively in the field of medical sciences. Among the medicinal plants, one may encounter few specimens like the aforementioned plant, which enjoys widespread distribution across various regions of the globe and boasts a diverse array of uses that contribute to its renown. The aim of the present study was the synthesis of Yarrow extract evaluation of its antibacterial effects on a group of intestinal bacteria and comparing its antibacterial properties with phenol.

In this experimental study, Yarrow plant extract was extracted with the hydroalcoholic method. The aerial parts of Achillea ageratum plant with herbarium number 1753 were prepared from the slopes of Ardabil mountains and after determining the identity, the extract of this plant was extracted by hydroalcoholic method. In this method, after preparing the plant and drying the aerial parts of the plant, 10 g of it was crushed in a sterile mortar, then it was poured into an Erlenmeyer flask, and 50 mL of 100% ethanol was added to it. After 24 hours of mixing in a magnetic stirrer using a Buchner funnel with Whatman filter paper and a vacuum pump, the remaining components of the plant were separated. Then, a certain amount of distilled water (20 ml) was added to the desired solution and placed again in the magnetic stirrer whose temperature was set at 80 degrees Celsius, so that the alcohol was completely removed from the reactor. The Antibacterial effect of yarrow extract was performed by disc diffusion method and micro broth dilution on standard species of Enterobacteriaceae families including the standard bacterial strains of Klebsiella pneumoniae (ATCC:10031), Escherichia coli (ATCC:23591), Shigella dysentery (ATCC:25922) and Enterobacter aerogenes (ATCC:13048). All experiments were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

In the present study, the growth rate of bacteria decreased by increasing the concentration of yarrow extract. The MIC of Yarrow plant extract for Klebsiella pneumonia and Enterobacter aerogenes was obtained in %6.25 and for Shigella dysentery and Escherichia coli was obtained in %12.5 and %25, respectively. Also, the MBC of extract for Shigella dysentery, Klebsiella pneumonia, and Enterobacter aerogenes bacteria was obtained in 25%, and for Escherichia coli it was obtained in 50%. The results of MIC and MBC show that the most sensitive bacteria to yarrow extract among the studied bacteria is Enterobacter aerogenes and the most resistant is Escherichia coli. The diameter of the inhibition zone for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria was obtained at 19, 18, 20, and 23 mm, respectively. In this experiment, Enterobacter aerogenes bacteria were the most sensitive and Escherichia coli was the most resistant among the investigated bacteria. Comparative investigation of the antibacterial properties of yarrow extract with phenol, showed that yarrow extract had a lower killing effect than phenol at 5, 10, and 15-minute contact time. In this test, the most resistant bacteria are Shigella dysentery and the most sensitive bacteria are Escherichia coli and Enterobacter aerogenes. The reason that the type of resistant and sensitive bacteria was slightly different in the method of comparing the antibacterial effect of yarrow extract with phenol with the results of MIC, MBC, and non-growth halo diameter is related to the reduction of contact time of the extract with bacteria.

The results of the present research show that the hydroalcoholic extract of the yarrow plant is very effective in the removal of gram-negative intestinal bacteria. Also, the hydroalcoholic extract of the yarrow plant is more effective in removing gram-negative bacteria than phenol

Highway construction projects, due to the frequent repetition of many of the activities and buildings during the execution process, are known as linear-repetitive projects. In this projects work Interruptions and resources unemployment is causing time and cost waste. So scheduling as result to reduce time and cost waste, is extremely important. The proposed method in this study to scheduling optimization of highway construction projects is based on one of the principles of lean thinking in removal of the wastes (Muda). And Genetic Algorithm and NSGAII approach has been used to solve scheduling problems. Given that in many cases because of uncertainties in terms of project, time and cost of the activity can not determine conclusively, thus it is seen based on fuzzy approach to this problem too. The main advantage of this method is the special attention the continuity of work between units, so that work interruptions and the resources unemployment reduced to the lowest possible. Thus reducing of wastes, project will be closer to lean construction.

Biomass is a key factor in dynamics evaluation of ecosystems, biodiversity level and their stability. Biomass measurement is performed every year to evaluate range ecosystems (investigating the trend of changes), range management (suitable browsing systems) and cover assessment in rangelands. As direct biomass measurement is time-consuming, has costs and destroy rangelands non-destructive methods by modeling can be taken into consideration. On the other hand, introduction of a suitable non-destructive method for biomass estimation that has high speed and precision and low sampling costs has been of importance according to wide areas of range ecosystems in dry parts of Iran, low vegetation cover and sensitivity to destruction. This study was aimed to estimate the biomass of three range species of Polygonum salicornioides, Astragalus ebenoides Boiss, and Astragalus coluteopsis Parsa by an ecological model using a non-destructive method in Sepidan, Iran. The studied species were perennial. Parameters of mean diameter of canopy cover, perimeter and height were used to determine the ecological equations to estimate biomass. About 30 samples of each species were selected for this purpose and measurements were performed in their blooming season. After the measurement of these parameters for each species in the range, their biomass was determined by cut-and-weight method and the ecological equations were constructed. The results showed that the obtained equations were precise enough to estimate biomass due to their correlation coefficient. Between the parameters of mean diameter of canopy cover, perimeter and height mean diameter of canopy cover had the highest correlation with biomass. In all three species, perimeter had the highest correlation after diameter. In general, the results showed that biomass of each species can be estimated by measuring its mean diameter of canopy cover and using the obtained equations for the studied species.

Management plays a major strategic and determining role as the main factor of productivity in every small and large scale social systems. This makes developed countries to invest heavily on development and enhancement of managerial capabilities and skills. This research aimed to survey the present status of middle level managers of RIPI considering managerial training components in order to provide a suitable context needed for designing a managerial development program. 150 of senior, middle and subordinate managers of RIPI/Tehran participated in this study. After reviewing literature on abilities and capabilities needed for managerial development, six elements including "managerial role, managerial skills, managerial abilities, managerial capabilities, managerial knowledge and philosophical minding" were considered as the managerial capabilities in the way to develop managers. Questionnaires (selected in Lickert scale) were used as the means for collecting data to evaluate present managerial status of RIPI mangers, and were filled by senior, middle and subordinate managers. The findings show that the present status of RIPI/Tehran middle level managers is in a relatively acceptable and optimum situation considering the merits and managerial training capabilities. In addition based on the survey and the results of Kruskal-Wallis test, there is a significant difference among the opinions of the three groups (senior, middle and subordinate managers) with regard to present status of middle level mangers in all six components except for managerial knowledge and philosophical minding.