According to the agency problems, the auditing fees can be changed in companies with Free Cash Flow (FCF). This research investigated the hypotheses of how the relationship between FCF and growth opportunities of the company causes higher auditing fees. This research is aimed to determine whether or not there is any significant relation between Free Cash Flow and Auditing fees. To this end, the data required were collected through 50 companies as the members of Tehran stock Exchange during 2003-2008 by using Rahavard Novin software and TSE site. Multivariate regression was used to test the hypotheses. The research included 3 hypotheses investigating the relationship between Free Cash Flow, Debt, divided interest of the company and auditing fees. The results showed that the companies by higher Free Cash Flow paid more auditing fess and also the companies with lower debt and divided interest paid lower auditing fees.

The neoclassical growth model is tested by use of panel data procedure in this research. In the econometric test, simoultanously time series and cross detection will be compared on the basis of panel data method through which their observed points increase and consequently the estimation efficiency will be increased. The examination of neoclassical growth theory has been done with reference to external & internal factors of 52 selected countries from 1960 to 2000. The independent variable of model has been selected on the basis of the result of previous research which explains the result in three separate models: developed countries, developing countries, and whole countries. These factors are such as: Gross National Products with lag of period, work force age, growth rate, education level, the change of capital accumulation and economic trade volum. The consequences of this research is that: neoclassical growth model can explain the major part of economic growth of the countries with use of internal variables. Also with the use of panel procedure of fixed effect, we can see the fundamental differences and structure of the growth process for different countries; and show how the economic, and social conditions affect on the growth.

This study was conducted to assess the removal efficiency of fast green FCF (a dye) from aqueous medium using the photo-Fenton process. Fenton's reagent, a mixture of hydrogen peroxide (H2O2) and ferric ions (Fe3+), used to generate hydroxyl radicals (·OH), was used to attack the target contaminant and degrade it. A visible light source was used to provide the radiation needed in the photo-Fenton method (i.e. H2O2/Fe3+). The effects of varying the parameters of ferric ion, fast green FCF and hydrogen peroxide concentrations, as well as pH, and light intensity on the reaction rate were determined. More effective and faster than Fenton's reagent in removing fast green FCF, the results show that the photo-Fenton method completely oxidizes and degrades fast green FCF into CO2 and H2O. A tentative mechanism for photobleaching of the dye is proposed.

The electrochemical oxidation of a food dye, fast green FCF has been investigated at a glassy carbon electrode using voltammetric techniques. The dependence of current on pH, concentration, scan rate and excipients was investigated to optimize the experimental conditions. According to the linear relation between peak current and the fast green concentration, differential pulse voltammetric method for the quantitative determination in spiked urine was developed. The linear response was obtained in the range of 30 μ M to 0. 2 mM with a detection limit of 0. 8 μ M. The proposed method was applied for the detection of fast green in food and urine as a real sample.

Non uniform flow Transverse velocity distribution in the main channel’s interface zone with floodplain in compound channels cause uncertainty to estimate in following parameters: the water surface profile, flood routing and sediment and pollution transport. The correction coefficients, (α) and (ß) were used respectively, to employ the impact of this uniformity on the kinetic energy and momentum values. In this study, via FCF data for compound channels, the influence of floodplain width (4.1, 2.25 and 0.75 m) on α and ß coefficient was investigated in symmetric and asymmetric compound channels. According to the results, the maximum value of α and ß was increased, due to increasing the width of the floodplain. Finally, the flow discharge was determined, with α and ß calculating values via CES software. Afterward, these values were compared with FCF laboratory data. The normalized root mean square error (NRMSE) was estimated in appropriate range, it equal to %15.6. This investigation showed that the high performance of the CES in determining the hydraulic parameters of flow such as discharge, in symmetric and asymmetric compound channels. But in general, this software overestimated the value of discharge.

Todays gamma knife radiosurgery is used widely for treatment of very small brain tumors. In order to investigate accuracy of dosimetry and treatment planning calculations, using Monte Carlo simulation with dedicated code named as beamnrc including non-CT data and CT data options is necessary. The aim of this study is choosing the best options in order to have an accurate tools based on their advantages and disadvantages. In this study, gamma knife unit 4C along with standard water equivalent phantom and EBT3 films were used to obtain dose distributions. Monte Carlo simulation was done with non-CT data and CT data options of the code and their resulting dose were compared. Comparison the calculated and measured dose distributions at X, Y and Z axis showed gamma value below 1 which verified Monte Carlo simulations. Also comparing the dose distributions from both non-CT data and CT data with each other implies that there is no significant difference between two methods. Based on the obtained results using non-CT data and CT data results in the same dose distribution. So for simplicity, using non CT data for regular phantom shapes is preferred.

The highly cross-linked PDMA star polymer (PDMA-b-PEGDMA) was successfully synthesized by group transfer polymerization (GTP) using 2-(N, N-dimethylamino)ethyl methacrylate (DMA) and cross-linking agent ethylene glycol dimethacrylate (EGDMA) monomers. Highly cross-linked polymer as a huge molecule has many functional groups. Thanks to these properties, dye adsorption performance of this kind of polymer was investigated. Sunset yellow FCF (SY) dye was used to determine whether the polymer showed adsorption properties. The effect of solution pH, dye concentration change and adsorbent amount on adsorption were investigated and the most effective adsorption conditions were determined for polymer. According to these parameters, the reaction rate constants in the dye adsorption of highly cross-linked polymer and the thermodynamic parameters (Δ, H°, , Δ, G°,and Δ, S°, ) of the adsorption were calculated. The reaction was spontaneous (Δ, G°,  , < , 0) at all temperatures (20 °, C, 35 °, C, and 50 °, C). Kinetic of adsorption of SY dye onto polymer was studied, as well as its adsorption isotherm. At the last stage of the study, recovery of the polymer was carried out. The polymer was recovered using the dissolution–, precipitation method. Adsorption studies were performed using UV–, Vis spectrophotometer. The characterizations of the synthesized highly cross-linked star polymer and the recovered polymer were carried out using proton NMR (1H NMR) spectroscopy and gel permeation chromatography (GPC).

Audit fees in relation to the agency problems can charge in companies with excess Free Cash Flow (FCF). This Research tests, several hypotheses about how the relation between FCF and company growth opportunities causes higher Audit Fees. In This study we try to find any direct and positive relation between Free Cash Flow and Audit fees. Variables which are used in this study are: Free cash flow, debt and dividends.The population is 430 companies listed in Tehran stock exchange. We selected 300 companies from the population for a period of 1382-1387.For literature review purpose we conducted a survey library method. For testing hypotheses we use the data from financial statements, Rahavard Novin, TadbirPardaz, Sahra soft wares, Bourse library and Tehran Bourse archives.Pearson coefficient of correlation and regression model are also used.The present study consists of three hypotheses, the results suggest that firms with high Free Cash Flow (FCF) bear, higher audit fees and firm high (FCF), levels of debt, dividends also bear, higher audit fees.