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Aluminum nano-films are one of the functional elements that have various applications in different fields such as strengthening cement base materials, improving the performance and efficiency of concrete, and enhancing the mechanical and volumetric properties of clay. In this study, the mechanical responses of aluminum nano-film are investigated under uniaxial tensile and compressive tests using the molecular dynamics (MD) method. The initial configuration of the nano-film is constructed based on a 3D aluminum core—alumina shell model that provides a suitable description of surface oxidation in the nano-film. This model is useful to determine the influence of surface oxidation on the mechanical behavior of nan-film. Because of the accuracy and competency, the inter-atomic interactions are evaluated using the EAM+CTI potential, which is a hybrid potential consisting of two components, i.e., EAM and CTI potential, such that it can also take into account the electrostatic interactions between the atoms. After establishing the initial configuration, the energy minimization process is performed on the nano-film, and then its temperature and pressure are adapted to the environmental conditions through the relaxation process. The MD analysis is accomplished by the open-source LAMMPS software, and the visualization of outputs is performed by the open-source OVITO software. The periodic boundary condition is imposed on the lateral sides of the nano-film to eliminate the free surface effect of the atomistic analysis. The tensile and compressive tests are applied to the nano-film in accordance with the experimental tests, and the stress—strain curves are determined. The concept of Virial stress is employed to calculate the stress of the atomic model, which is equivalent to the conventional Cauchy stress in classical mechanics. In order to diminish the dynamic effects, deformation is incrementally applied to the nano-film, such that at each increment, a small strain is gently imposed, then the nano-film is relaxed under the deformed conditions, and finally the stress and strains are evaluated. The numerical simulations are verified by comparing them with experimental data, which demonstrates the acceptable accuracy of the obtained numerical results. The influence of various parameters such as the thickness and the percentages of oxide layers are investigated on the mechanical response and stress-strain curve of aluminum nano-film under the uniaxial tests. It is demonstrated that the thickness of the oxide layer significantly impacts the mechanical behavior, such that the hardness and energy absorption capacity of the nano-film is increased considerably by increasing the percentage of the oxide layer thickness. However, increasing the total thickness of the nano-film leads to a decrease in the Young’s modulus and elastic limit of the specimen. It is because of the decrease in the percentage of oxide layer thickness by increasing the total thickness of the nano-film. Point defects are one of the important imperfections in the crystal structures of atomic configuration that have a significant effect on the mechanical behavior of materials. In order to investigate the influence of point defects, different percentages of voids are generated by randomly omitting some atoms in the nano-film domain. The generated specimens are analyzed under the uniaxial tests, and their mechanical characteristics are evaluated. The numerical simulations demonstrate that the hardness of the nano-film is significantly reduced by increasing the point defects.
 

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Today, with the increase of population and the uncontrolled growth of cities and the advancement of technology and the consequent destruction of the environment, the living conditions of many living beings have become difficult, which has caused man to move away from nature and lack comfort and tranquility; Biophilic design by facilitating and improving the quality of human communication with nature around it, using global sustainable design strategies tries to control environmental degradation to environments with improved social and cultural conditions, along with creating the ability to understand and process and benefit from past experiences. Create to ultimately improve the quality of urban life. In his extensive research, Professor Beatle has identified Oslo as an ideal city for biophilic urban planning. For this purpose, in this research, by considering this city as a model and adapting this city with Moallem Boulevard in Ramsar city in order to improve the condition of the boulevard in terms of biophilic urban planning, the present article tries based on descriptive-analytical method and To evaluate the measurements qualitatively and by describing, analyzing and interpreting the contents, to provide effective solutions on improving the quality of the environment with the approach of environmental perception in biophilic urban design.The results show that Moallem Boulevard in Ramsar has the potential to achieve biophilic urban design based on a comparative study with the city of Oslo, and by using the components of environmental perception and biophilic design, proposes plans to improve the quality of citizenschr('39') environment And created visitors.

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Performing duties and offering decent services to citizens by municipalities, calls for supply of credit and financial resources. During the last two decades, revenues generated by purchasing surplus density or in other words, revenue from granting rent licenses to urban lands has played a central role in providing income for the metropolis municipalities of the country. Financial dependence of municipalities on this source of income and lack of reliable and sustainable sources of revenue at least to meet the permanent costs, disrupt the medium and long term financial budgeting and planning of municipalities. Considering inefficient and less rational methods and illogical density sales, necessitates more efforts to be made to study income structure of municipalities and demands effective help to be provided to this pervasive and public institution by investigating the roots of rent seeking in this structure. A basic assumption in this study is that some income codes including sales densities influence the formation of the municipality rent in a large extent. Therefore, by using the statistical data in Isfahan Municipality, the share of different sources of income in total municipality revenues during the years 1983 to 2005 is investigated and the research hypotheses are analyzed. The results indicate that the income structure of Isfahan municipality is rather based on rent seeking than relying on economic potentials and structures.

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During recent decades, decentralization has been regarded in various societies as an instrument for making public sector policies more efficient, and its numerous advantages and disadvantages have been discussed. Each decentralization policy has three dimensions including Political decentralization, Administrative decentralization and Fiscal decentralization. This paper evaluates the impact of fiscal decentralization on the interaction between economic growth and regional equity in the distribution of fiscal resources in provinces of Iran by using panel data method. The results verify a nonlinear relation between fiscal decentralization and economic growth, so that economic growth rises with fiscal decentralization increase to a specific level and then it decreases because of disadvantages of decentralization. There is a relationship between fiscal decentralization and equitable distribution of fiscal resources too. Growth and equitable distribution variables change in the opposite direction between two levels of decentralization, and move in the same direction out of this interval. There is also a tradeoff between growth and equitable distribution of fiscal resources.  

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Tax reform as a part of financial system’s reforms constitutes the core of fiscal policies and economic adjustment process. The widening tax base and rationalizing tax rates are main priorities in this regard. This paper aims to calculate optimal commodity tax rates and marginal cost of social welfare resulting from indirect taxes in Iran. The calculation of marginal cost of social welfare requires determining the own and cross price elasticities of demand and optimal tax rates for goods and services. These parameters are obtained by estimating demand function of ten good and service groups in a linear expenditure system. This system is estimated through seemingly unrelated regression method using data of ten expenditure deciles of urban households in Iran during 1996-2010. The optimal tax rates are calculated using Ramsey method in a multi-person world and Bergson-Samuelson's social welfare function. In this model, a social welfare function is maximized with respect to given tax revenue of government using Lagrange method. Results show that when social inequality aversion parameter is zero, optimal tax rates almost are equal. By increasing this parameter, which fairness rather than efficiency is considered, these rates are diverged, in a way that some commodity groups are entitled to get subsidy. In addition, as social inequality evasion parameter increases, the marginal cost of social welfare resulting from change in commodity tax rates decreases, and welfare loss gets very small in the highest social inequality evasion rate. So, decreasing subsidy among all good and service groups receiving subsidy, and increasing tax on other groups lead to decrease in social welfare.  

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Introduction:
According to the models of growth, renewable and non-renewable energy  affect economic growth, but the consumption of renewable energy due to less pollution, contributes to sustainable growth. So, countries strive to create the conditions for the use of renewable energy, such as electricity. By balancing competition in market such as the electricity market, on the micro level surplus of consumer and producer welfare is maximized without government intervention, and the incentive for the private sector to enter the market increases. On the macro level, due to lower prices and increased production, electricity consumption as renewable energy increases and reduces environmental degradation and increases sustainable growth. Over the past decades, in the electricity industry, natural monopoly conditions have been established in the sectors of production, transmission and distribution, and the surplus of consumer and producer welfare has not been maximized, so government intervention was justified. In recent years, due to technological advances and the elimination of natural monopolies, the incentive for the private sector to enter the electricity sector has been strengthened. The purpose of this article is to measure the degree of competition in 9 electricity companies in Iran during the period 2011-2019.

Methodology: 

In order to measure the degree of competition in Iran's electricity industry, two structural approaches, i.e., Entropy coefficient and non-structural Panzar-Rosse were used. 

The entropy measure is used as an alternative to variance, in fact entropy is the inverse measure of concentration, when entropy increases, concentration decreases:
E=i=1nSi.log1Si    ,    0≤E≤log⁡(n)                                                         (1)
Si  is the market share and the value of this index is equal to zero for the monopoly market and increases nonlinearly as the market becomes more competitive.
Measurement of degree of competition by Panzar-Ross method, using the GMM method is as fallows:
LnTRit=α0+α1LnQit+βLLnWLit+βKLnWKit+βELnWEit    (2)  

WLit
  is the labor input price, WKit
  is the capital input price, WEit
  is the energy input price of the power generation company i in the time period t. TRit
  is total revenue, Qit
  is production of the i-th power generation company at time t. In the dynamic specification, the Panzar-Rosse criterion for evaluating the market structure is defined as follows:

PRH=i=13βi1-α1                                                                                                       (3)
If i=13βi=1 , the market is competitive and a decrease (increase) in the price of inputs causes the same decrease (increase) in marginal cost and marginal revenue. If 0<i=13βi<1 , the market has monopolistic competition and is between competition and monopoly.

Results and Discussion:

The calculation of entropy coefficient, which is one of the structural methods in measuring competitiveness, obtained a number equal to 0.215 for the Iranian electricity industry during 2011-2019. Considering that the mentioned number is between zero and one, it shows that the concentration in Iran's electricity industry has decreased during the period under review and this industry has been placed in a state between competitive and monopoly. In other words, the conditions of the electricity industry have moved out of the traditional state and full monopoly, although it still needs to establish arrangements to become more competitive and close to full competition. On the other hand, Panzar-Rosse non-structural method was also estimated and its index was calculated, which obtained a value of 0.253. This amount of Panzar-Rosse non-structural index also confirms the results of the non-structural approach in Iran's electricity industry. Due to the fact that the results of both structural and non-structural approaches in calculating the level of competitiveness in Iran's electricity industry confirm each other, more confidence is created regarding the obtained result.

Conclusion: 

Considering the important and effective role of electricity in other industries of the country, the existence of more competition that leads to a decrease in the price and increase in the production of electricity, from a micro point of view, it has led to an increase in consumer and producer surplus, and from a macro point of view, it has also led to a reduction in environmental pollution. Reducing the exploitation of non-renewable energies and as a result of intergenerational justice and ultimately the realization of sustainable growth and development. Although the results of the calculation of competitiveness indicators indicate that the electricity industry is moving away from the monopoly state and moving towards the competitive state, more efforts should be made in order to increase the degree of competition and achieve complete competition in the country.

 In this way, the country's economic managers and policy makers should increase the number of power plants in Iran's electricity network while removing the existing legal obstacles on the path of restructuring from monopoly to full competition in the country's electricity industry in order to reduce the level of concentration and monopoly in Iran's electricity market. On the other hand, creating a suitable environment for the correct and healthy competition of electricity companies, improving the productivity of production inputs and using the optimal combination of inputs through research and development, as well as short-term and long-term planning to improve the level of production and improve the cost structure, and encouraging and supporting elites and inventors in line with the development of new electricity production plans and technologies such as solar electricity technology can help to make the structure of the electricity industry more competitive.

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Introduction: 

The return of the stock market is affected by several factors; although some of which are not economic, they strongly affect the financial markets. The Covid-19 epidemic is also among these factors that has severely affected the global economy, empathetically the financial markets. Therefore, considering the importance of this epidemic in the stock market, the current study evaluates the effects of the Covid-19 epidemic crisis on the stock return index of the financial markets of China, America, and France; besides, it examines its spillover effects on Iran. To investigate the contagion of turbulence and the direction of spillover from the mentioned countries to Iran, the weekly data of the stock return index available on the websites of the Iranian Stock Exchange have been used. Moreover, the stock exchange of foreign countries during two periods: before the outbreak of the Covid-19 epidemic (January 2018 to December 2019) and the time of the outbreak of the Covid-19 epidemic (January 2020 to December 2021) have been examined. Then Oxmetrics software was used to check the conditional correlation, and SPSS software was used to measure the stationarity and unconditional correlation.
Methodology:
The present research evaluates the spillover effects of the covid-19 epidemic on the stock return index of the financial markets of China, America, and France and examines the mutual relationship between the aforementioned countries and Iran using the weekly stock return data of Iran and foreign countries. It has been analyzed using (DCC-GARCH) and (CCC-GARCH) models.
Results and Discussion:

In this article, αii represents the effects of arch in each of the variables' past period turbulences, and αij represents the effects of the shock of variable i on the current shock of variable j. This spillover effect is calculated as the square of the residuals arising from the forecasted yield patterns. Garch effects are considered as βii. In other words, βii shows the stability of the shock in each of the series.

 ρij also expresses the conditional correlation between two variables, which provides a representation of their simultaneous movement. Of course, both terms αij and β can indicate the overflow between indicators, because the shock overflow effect is determined by non-diagonal values. In the constant conditional correlation model, coefficients αii and βii are significant. In other words, they represent the amount of shock transmission in the conditional shocks of countries' returns.

Conclusion:

The results indicate that in the post-epidemic period, the Iranian stock market experienced a decrease in stock returns, which can be caused by factors such as the imposition of sanctions and the stagnation of economic activities in addition to the spread of Covid-19. Also, the collapse of the Iranian stock market, which occurred in August 2019, led to the confusion and pessimism of more and more investors and finally led to the withdrawal of capital from the stock market. In such an uncertain and chaotic atmosphere, the spread of Covid-19 also aggravated the existing conditions due to the restrictions and also the implementation of government quarantines. Also, the results show that at the moment of the outbreak of the Covid-19 virus, all the sample countries have faced a decrease in stock returns. During the covid-19 epidemic, the impact of the Iranian stock market on China has been greater than that of other studied countries, which is important because China and Iran are each other's trading partners. It should be mentioned that during this period due to restrictions on the borders, the relationship between Iran and China became prominent. Also, Iran's stock market is not strong enough to influence global financial markets including China, America and France.

 The growth of the stock return index has been increasing during the four-year period (2018-2021) in China, America and France, however the stock return index of Iran has been decreasing. The growth of China's stock returns during this period has been higher than that in the other studied countries. Also, the stock return index of all sample countries has faced a decrease in the stock returns during the outbreak of Covid-19.