فهرست مطالب mahdi nejati

Water scarcity is a global and regional concern and requires a global and regional perspective. The water shortage crisis that the world and consequently Iran is experiencing shows the importance of water resources and the optimal use of those resources. Therefore, water supply is of special importance for the people of the world and different economic sectors, and any disruption in its process can lead to social and economic problems. Most policymakers and researchers believe that water scarcity and its effects on developing and developed countries as a global threat. It is clear that the issue of water has become an area of international cooperation. Concerns about water scarcity and water management problems in different parts of the world have made water issues the focus of many international and non-governmental organizations (NGO). According to studies, the formation of regional water markets is one of the methods of water resources management. To reach regional water markets, one of the effective tools is to create a suitable platform for economic convergence. Convergence is generally centered on gravity models. In the structure of these models, the basic condition for achieving economic convergence is convergence in production and productivity. This study has dealt with the most important variables affecting economic convergence through the productivity channel. Because distance is important in the formation of regional water markets, Iran has been selected and studied for convergence analysis with neighboring countries (Pakistan, Turkey, Russia, Kazakhstan, UAE, Armenia, Azerbaijan, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia). Also, in order to see the effect of productivity shocks in the best possible way, a dynamic computable general equilibrium model has been used. The data required to simulate the scenario presented in this study are taken from the ninth version of the GTAP database. This version includes the world with 140 regions or countries, including Iran and 57 economic sectors. 57 parts of the model have been changed to 13 parts and 5 production factors to 8 production factors, which are as follows. Sectors include: Agriculture, Other Agriculture, Livestock, Forestry, Fisheries, Coal, Oil, Gas, Industry, Petrochemicals, Electricity, Water and Services. Production factors include: water, land, rain fed land, pasture land, skilled labor, unskilled labor, capital and natural resources. The characteristic of computable general equilibrium models is that it different scenarios can be evaluated and examined in the context of general equilibrium. For the productivity variable, the concept of total productivity of production factors is used, which is one of the factors affecting production and convergence. The results showed that positive productivity shocks have led to the expansion of foreign trade between Iran and neighboring countries. In practice, the expansion of trade can be considered as a factor for economic convergence between Iran and neighboring countries. Also, the productivity shock, in addition to slowly increasing economic prosperity, has also led to a kind of stability and stability in economic growth. Therefore, if productivity is an inevitable movement in the economic use of water resources, it can lead to economic convergence with an emphasis on water trade. Also, the result of the dynamic model shows a positive outlook for Iran and neighboring countries. Since economic convergence is a precondition for reaching regional water markets, Therefore, convergence with border countries is a suitable strategy for the Iranian economy to form regional water markets. It is natural that the formation of regional water markets can provide a good opportunity to deal with the crisis in water resources and also increase prosperity and stability in economic growth. So that the effect of the welfare change scenario shows that this index in Iran will increase from 31952.9 in 2023 to 2793848 in 2030 and this shows the positive effect of the regional water market on welfare. So that the effect of the welfare change scenario shows that this index in Iran will increase from 31952.9 in 2023 to 2793848 in 2030 and this shows the positive effect of the regional water market on welfare. According to the literature on gravity models, total value added, which constitutes GDP, is the most important variable affecting the convergence. Therefore, the effect of productivity shock on GDP indicates the necessary potential for economic convergence. The result of the dynamic model showed that the effect of positive productivity momentum on the change in the value of GDP is positive. It should be noted that, in the long run, by 2030, Iran and neighboring countries will reach a relative stability in terms of GDP value. Thus, the flow of productivity in the long run can provide stable conditions for GDP. Accordingly, the appropriate strategy for the Iranian economy in the formation of regional water markets can be considered as convergence with neighboring countries, which will also provide a good opportunity to deal with the crisis in water resources.

The purpose of this article is to understand the effect of the outbreak of infectious diseases on the economy and also to analysis the role of government under pandemic crisis conditions. For this purpose, a dynamic stochastic general equilibrium model is used. After calibrating the parameters based on the quarterly information of Iran's economy during the period of 1991-2016, in the baseline scenario, it is assumed that the government has no involvement in the economy; In other words, the government pursues a state of fiscal passivity and shows no fiscal reaction to the change in endogenous variables after the outbreak of pandemic disease. Subsequently, in other scenarios, the government reacts fiscally to the outbreak of the pandemic, given the different conditions of production and public liability. The results of the study of fiscally active scenarios compared to the state of fiscal passivity indicate that the effect of government expenditures shock as a standard deviation on macroeconomic variables under pandemic disease conditions, has led to much less feedback.

The nonlinear dynamic response, Limit Cycle Oscillations (LCOs), of high aspect ratio wings using a novel indicial aerodynamics in subsonic flow is investigated. Using the nonlinear beam theory, the structural model is derived including the in-plane and out-of-plane bending and torsion motions, all nonlinearities up to cubic order arising from large deformation, mass distribution, and cross-sectional mass imbalance. Based on new approximations of the indicial functions, a comprehensive unsteady aerodynamic model is used. Such an indicial aerodynamics while being coupled to nonlinear structural equations can result in a unified nonlinear aeroelastic formulation in both the incompressible and subsonic compressible flow. The effect of flight conditions, wing tip initial disturbances, stiffness ratio between bending modes, and nonlinearity due to inertia and cross-sectional mass imbalance on the characteristics of LCO are discussed. The results show that the compressibility can affect the LCO boundary up to 12 percent which implies that an appropriate Mach-dependent aerodynamics is required to achieve a more reasonable and realistic description of dynamic behavior of the system. It is shown that the presence of LCO before the linear flutter speed depends on initial disturbances as well as wing characteristics.

According to studies, a financial market based on the power law as According to the literature, a financial market based on the power law as a dynamic system can reach a critical point (i.e., a financial crisis) and even go up to the infinity. In this study, four stock exchanges in Tehran, Moscow, Abu Dhabi, and New York were selected based on the availability of credible statistics and the observation of important economic areas in the global geography. Two questions were then formulated as follows. Firstly, did the four markets face crisis and how much was the magnitude of each one? Secondly, if the crisis affected the markets in 2007- 2009, how much was the value-at-risk and the expected shortfall in the crisis? The results indicated that financial crises occurred in the four markets based on the power law and Wakeby distributions and the magnitude of each one was also determined. It was also found that the financial crisis in 2007- 2009 affected all four stock exchanges. The crises that occurred in the Tehran Stock Exchange, respectively included: the first privatization impact of the stock exchange in 2003, the United Nations Security Council's sanctions in 2010, the devaluation of the national currency in 2012, the global financial crisis in 2007, the implementation of the nuclear deal between Iran and the Group 5+1 in 2016, the decline in oil prices in 2014, the nuclear negotiations in 2015, the first nuclear negotiations in 2013, the beginning of the Second Gulf War in 2003, the Russia conflict in 2013 and the Lausanne nuclear deal in 2015. The four crashes in the Russia’s market, respectively were: the global financial crisis in 2007-2009, the economic crisis in Asia in 1997, the Russian financial crisis in 1998 and the Russian Ruble collapse in 2014-2016. Two financial earthquakes occurred in the United Arab Emirates’ market, respectively included: the global financial crisis in 2007-2009 and the effects of the decline in oil prices in 2014. In turn, the crises affected the United States’ stock market were the global financial crisis in 2007, the crash in 1987, the stock markets fall in 2011, the stock market downturn in 2002, the economic crisis in Asia in 1997, the Russian financial crisis in 1998, the September 11 attacks in 2001, the spring in 2001, the flash crash in 2010, the technology bubble collapse in 2000, the stock market selloff in 2015-2016, respectively. Moreover, the worst losses in each market were determined by the value-at-risk and the expected shortfall in the recent global crisis based on the duration. The value-at-risk and the expected shortfall represented the worst possible loss at the end of the next trading day at 95% and 99% confidence levels. The goodness-of-fit statistic (KS) showed that GPD fitted well with the returns up to the given thresholds. Besides, the results of the estimation of value at risk during the period of financial crisis in 2009-2009 showed that the worst daily loss will not exceed 1.1%, 16.1%, 4.2% and 9.1% in the next trading day in 95% of the time in the Iran’s, Russia’s, United Arab Emirates’ and United States’ markets, respectively. Further, it will not exceed 2.5%, 26.3%, 6.9% and 11% in the next trading day in 99% of the time in the markets. Based on the estimation of the expected shortfall, the worst daily expected loss will not exceed 2.3%, 22.8%, 5.9% and 10.2% in the next trading day in 95% of the time. In addition, the worst daily expected loss will not exceed 5.1%, 35.7%, 8.9% and 11% in the next trading day in 99% of the time in the four markets, respectively. It was also found that in the 2007-2009 Russia’s and United States’ stock markets experienced the greatest loss compared to the crash in 1998. Indeed, the financial shocks can lead to relatively great values of the worst expected loss; however their severity is different in each market studied. The results also revealed that the financial crisis with the highest magnitude in 2007- 2009 created a large potential loss and damage in all markets.

In this paper, a novel model based on the indicial functions concept is presented to calculate the unsteady aerodynamic loads in the incompressible and subsonic compressible flow. Indicial functions represent the two-dimensional airfoil response to a unit step change in the angle of attack or the pitch rate about the reference axis. In contrast to the incompressible flow where the aerodynamic loads can be determined in terms of a single indicial function, four indicial aerodynamic functions are required to find them in the compressible one. If the indicial functions are known, the unsteady loads can then be obtained through the superposition of indicial responses using Duhamel’s integral for any arbitrary motion. For the purpose of combination the aerodynamic loads for the entire subsonic flow speed range, i.e. 0≤M≤0.8, a new, efficient and Mach dependent approximations of the indicial functions are presented by using the analytical as well as numerical data. Using four instead of seven Mach dependent coefficients in the common indicial functions, the required coefficient are decreased from 28 to 16 to fully describe the aerodynamic loads. Utilizing the indicial functions, then a novel and convenient form of unsteady aerodynamic loads and the corresponding state-space representation is presented; having a unified formulation in incompressible and subsonic compressible flight speed regimes. Based on the strip theory as well as the modified lift curve slope, the finite span effect of 3D wings is also included. The generated indicial functions is validated against available results, which shows a good agreement.

Productivity of any country contact with share of that country of world trade directly. Also oil and gas have always been considered the most important commodity in the world. Given that Iran is among the main countries in the global energy business, it is important to be able to consider the influence of productivity of major trading partners of Iran in the energy sector. In this study the effect of productivity shocks of Shanghai group countries, as major energy-demanding groups, on the oil and gas sector is taken into consideration. On this basis, the original question of the paper is whether productivity shocks in the industry of Shanghai group countries have any effect on Iran's oil and gas sectors. To respond this question the computable general equilibrium approach for four economical sections (industry, oil and gas, agriculture, and services) and the social accounting matrix in 2004 and GTAP8 database have been adopted. The results indicate that if the trade of Iran with Shanghai group counties increases while productivity in the industry of Shanghai group countries increases 5%, it will cause an increase of investment and employment in the oil and gas sector in Iran.

One of the most important aspects in recombinant biologic production, based on GMP rules, is the accuracy of final product quality control, especially assessment of host cell macromolecules contamination rate in final product. The purification requirement can be eliminated when the yeast cell containing the recombinant protein is used as a host cell. It is possibile that the final product contaminated to the host cell protein during purification stages of HBsAg (HBV vaccine). The protein purification costs depend on the purification procedures required. Nowadays several companies produce commercial kits for identification and assessment of host cell protein contamination based on ELISA and Western blotting methods. But high prices, difference in sensitivity and lack of easy access to these kits sometimes create problems. So, in this study, two methods of Ammonium sulphate and caprilic acid precipitation technique were used separately for IgG purification. The results showed that IgG purification increased by 97% in caprylic acid method, compared with only a 77% increase in ammonium sulphate method. There were also significant differences in specificity and sensitivity between our standardized ELISA technique and using commercial kit (Cygnus CHO HCP).

Brucellosis is one of the five common bacterial zoonoses caused by a gram negative, non-spore forming, and facultative intracellular bacterial organism belonging to the genus Brucella. Although brucellosis is considered as a health problem for both men and domestic animals in many countries, any licensed human vaccine has not been designed and produced for it yet. To overcome the problem, currently, antigenic determinants of Brucella cell wall e.g. outer membrane proteins [OMPs] and lipopolysaccharide [LPS] are considered as potential candidates to develop subunit vaccines. Brucella abortus S99 used in the present study is obtained from the standard bacterial collection of Institute Pasteur of Iran. OMPs were extracted by deoxycholate extraction technique and further purification performed by sequential centrifugation and ultracentrifugation. Protein concentration was determined using the Nanodrop ND–10000 spectrophotometery. SDS-polyacrylamied gel electrophoresis (SDS–PAGE) was performed to determine the electerophoretic pattern and the molecular weight of the extracted OMP samples. OMPs concentration of B.abortus S99 has been measured and reported as 6.27 mg/ml. SDS-PAGE analysis indicated one protein band in the range of 36-38 kDa which would be classified as the porins of B.abortus S99. Extraction of B.abortus S99 OMPs with the applied method in the present study produced a satisfactory yield of OMPs. These proteins belonging to the second group of OMPs, called porins.

Fluoroquinolones, in particular ciprofloxacin have recently become the drug of choice for antibiotic therapy of invasive Salmonella infections in many countries. however, several treatment failures due to Salmonella strains with decreased susceptibility to ciprofloxacin have been reported. These isolates are still considered to be susceptible to ciprofloxacin according to CLSI interpretive criteria (MIC≤1 μg/ml) while they can not be detected by disk diffusion test. CLSI has recommended nalidixic acid disk diffusion as an indicator test for screening of Salmonella isolates with decreased susceptibility to ciprofloxacin.In this study the value of nalidixic acid susceptibility testing for screening of clinical strains of Salmonella with decreased susceptibility to ciprofloxacin was evaluated. Salmonella spp. strains have been isolated from several provinces in Iran during 2007-2008. The strains were identified by standard biochemical tests and serology. The susceptibility of the isolates to nalidixic acid and ciprofloxacin was determined by disk diffusion method. MIC assay for ciprofloxacin was determined by E. test. 28 out of 53 Salmonella strains (52.8%) were resistant to nalidixic acid. Disk diffusion testing showed that all isolates were susceptible to ciprofloxacin however 8 (15%) resistant nalidixic acid isolates showed decreased susceptibility to ciprofloxacin (MIC= 0.125 μg/ml) when tested by E.test. The results showed that nalidixic acid disk diffusion test can be considered as a reliable and costeffective method for screening of Salmonella strains with low level resistance to ciprofloxacin.