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Computable general equilibrium (CGE) models have become a standard tool of empirical economic analysis and were extensively used to assess the impact of trade liberalization by policy analysts. In this study, the effects of imports tariff reduction as a trade liberalization index are investigated on key economic variables using computable general equilibrium approach. The data used in this study are obtained from the social accounting matrix of year 2001 in which parameters of model are calibrated accordingly. Results of simulations show that if the imports tariff rate is cut by 50% and 100% across all sectors, total supply and investment will reduce while total exports, total imports, household income and consumption will increase.

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Aims: COVID-19 has affected a worldwide population, causing more than a million deaths from the end of 2019 until now; so the aim of this study was to determine the symptoms of COVID-19 in the Iranian population through a teleconsultation-based service to better deal with it.
Instrument & Methods: This study was a cross-sectional study that included 12125 individuals calling for COVID-19 screening and consultation from 2 March 2020 to 19 April 2020 with the census method. A telephone number was assigned for consultation with more than 70 nurses responding to first-level questions and more than 30 medical doctors responding to second-level questions. For statistical analysis, a chi-squared test and univariate logistic regression with SPSS 25 were used.
Finding: Cough was the most common complaint (41.3%), followed by shortness of breath (32.8%), and fever (31.5%). Confusion was the least common complaint (1.6%). Binary logistic regression revealed that men were at a higher risk of COVID-19 compared to women (OR:1.31, 95% CI 1.10-1.55, p=0.002). In addition, older age was a risk factor for COVID-19 (OR:1.02, 95% CI 1.02-1.03, p<0.001). Also, significant positive correlations were found between fever, chills, sore throat, shortness of breath, cough, body ache, and gastrointestinal symptoms with COVID-19 even after adjustment for gender and age.
Conclusion: Fever, cough, and shortness of breath were the most common complaints in individuals calling for COVID-19 teleconsultation. It’s suggested that in times of crisis, such as the Covid-19 pandemic, remote sensing can be done to raise public awareness and break the transmission chain.

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Regarding the importance of writing performance in mastering English language and considering writing as the most challenging language learning skill, the present study examined the relationship between personality traits with motivation and written performance in learners. The main purpose of this study was to examine the model fitness of the relationship between the personality traits and writing performance of learners with motivation mediation. To this end, one hundred twenty participants were selected from intermediate EFL (teaching, literature, translation) learners. Data were collected through Big Five Personality Traits questionnaire (John and Srivastava, 1999), Attitude/Motivation Test Battery (AMTB) (Gardner, 2004) and a timed writing Test. The results of the path analysis indicated a relationship between personality trait dimensions with motivation and EFL writing performance. Also extroversion, consciousness, and agreeableness indirectly had a positive and significant effect on writing performance. Learners’ motivation relatively intercedes the relationship between personality traits and writing. Finally, the findings of the study are discussed in relation to effective attitudinal variables and non-cognitive variables of personality traits for educational planners, writing courses teachers, and EFL learners’ motivation in language classrooms.
 
 

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In this study, at first the combined steam and organic Rankine cycles, have been stimulated with high-temperature wasted hot gases recovery, from the energy and exergoeconomic points of view. In the configuration of the combined cycles, the high-temperature wasted gases acts as the source of steam cycle evaporator, then the decreased temperature exhaust gas of the steam cycle evaporator, is used as the low temperature source of organic cycle evaporator. Afterward the effects of changing different parameters such as temperature of the evaporator and condenser of steam cycle and pinch temperature difference, on the amount of total output work, total irreversibility, energy efficiency, exergy efficiency and exergoeconomic variables have been checked. The results in base state show that, energy and exergy efficiency of combined cycles are 0.2782 and 0.5279 respectively and the amount of output work and total irreversibility are 71401kW and 43616kW respectively. Total exergoeconomic factor for the combined cycles is 12.47 percent, which represents a high exergy destruction in components and recommends raising the initial cost of components in order to improve the performance of system. The evaporator, turbine and condenser of steam cycle, are the components that should be considered from the perspective of the exergoeconomic, because they contains the maximum amount of total initial costs and the cost of exergy destruction.

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In this research, ammonia-water regenerative Rankine cycle driven by solar energy and LNG as it’s heat sink in condenser, is simulated from the energy, exergy and exergoeconomic point of view. A relatively new method is used to implement pinch temperature difference in heat exchangers which causes improving of the thermodynamic performance and output power of the system. Also heat exchangers are simulated by using heat transfer correlations of shell and tube heat exchanger in details. The results of based condition showed the suitable performance of natural gas cycle from the thermodynamic and exergoeconomic point of view and notifies the importance of using the natural gas cycle. Solar collector and condenser of ammonia-water cycle because of their high cost value, are introducing as the components that shoud be more concidered from the exergoeconomic viewpoint. The parametric analysis results show that in high inlet pressure of ammonia-water turbine, the exergy efficiency and the total cost of the system heve more suitable values while the net output power of the system decreases. Also by changing the ammonia mass fraction, changing of output parameters has a complicated patern. Finally by increasing the pinch temperature difference in heat exchangers, the decreased amount of system’s thermodynamic performance is more than the amount of system’s economical performance improvement.

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Considering the daily increase of consumption and expense of nonrenewable energies such as natural gas and electricity, application of clean and renewable energies such as solar thermal energy nowadays has been highly taken into consideration. In this research, at first, simple steam Rankine cycle and two different configurations of combined steam and organic Rankine cycles with parabolic trough solar collector as heat source are simulated from energetic and exergetic point of view. First configuration was basic steam rankine cycle with parabolic trough solar collector (PTSC) as heat source, and other configurations of the combined cycle worked as follows: In the second configuration (combined cycle with intermediate heat exchanger), with the increase of steam condenser pressure, heat dissipation in condenser is used as heat source for bottoming organic Rankine cycle and in the third configuration (combined cycle without intermediate heat exchanger), reduced-temperature solar fluid moving output of steam rankine cycle acted as the organic Rankine cycle heat source. Simulation results in the basic input state show that third configuration has the maximum amount of work and irreversibility and second configuration has the minimum amount of work and irreversibility which in this case, increase in the steam cycle condenser pressure leads to the reduction of work of combined cycle with intermediate heat exchanger, even lower than the simple steam cycle. On the other hand, second configuration has the maximum solar energy and exergy efficiency among three configurations which is due to the reduction of collector area required in this configuration.

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In recent years, the use of Gas Turbine-Modular Helium Reactor (GT-MHR) which operates in accordance with closed Brayton cycle with helium fluid as working fluid has attracted researchers’ attention because of its high efficiency, high reactor safety, being economical, and low maintenance costs. In the present study, a combined system, including GT-MHR cycle, Kalina cycle and Ammonia-water absorption cycle is investigated with respect to energy, exergy, and exergoeconomic. As the bottoming cycle, Kalina cycle and absorption cycle are used in order to avoid energy wasted by gas turbine cycle and to increase efficiency of energy conversion. The results of the simulated model show that, in the basic input mode, the overall work is 304462 kW, the overall exergy destruction is 289766kW and the overall exergy efficeincy of cogeneration cycle is 0.689kW. Also reactor, turbine and compressor in helium cycle are the component to which more attention should be paid with respect to exergoeconomic because the highest amount of cost rate is related to these components. At the end, parametric analysis is carried out in order to evaluate the effect of the changing pressure ratio of helium compressor, input temperature of helium compressor, input pressure and temperature of turbine and mass fraction of the base mode of the Kalina cycle on the output parameters.

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Agriculture is one of the responsible sectors for adequate food production and contribution to food security. However, due to the rapid population growth and increasing demand for food, this responsibility is becoming more and more challenging. The consequence of this challenge is the excessive exploitation of natural resources and destruction of the environment. This study aimed to investigate the cost structure, economies of scale, and inputs elasticities for the major farm crops of the Qorveh-Dehgolan Plain, in Kurdistan Province, through a translog cost function. The needed data were collected through a multi-stage cluster sampling survey in the 2017-2018 cropping year. The results showed that the average share of water input in the total production cost of the studied products was 12%. Results also showed that all ordinary own-price elasticities of demand for inputs were negative and smaller than one. However, the results of Allen-Uzawa's own price elasticities showed that demands for inputs could be elastic. Ordinary and Allen-Uzawa own price elasticity of water input were -0.76 and -6.7, respectively. The results also showed that wheat, tomato, barley, and alfalfa farms in the area under study were facing economies of scale, on average, while potato, cucumbers, and sugar-beet farms were facing diseconomies of scale.

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As for the buy-out clause, if the player pays the buy-out fee, he/she can terminate the contract prematurely without specifying any cause. The current research principally aims to analyze the legal nature of the buy-out clause and what are its legality conditions in FIFA regulations and Iranian law. Regarding the nature of the buy-out clause, different perspectives have been raised. From a perspective, the buy-out clause can be classified as a liquidated damage clause and is subject to prohibition of exorbitant and unfair liquidation damage provision. According to another perspective, the nature of the buy-out clause is a contractual right. The buy-out fee is in consideration for the exercise of contractual rights. Currently, the latter opinion is preferred by FIFA. Under Iranian law, basically, the nature of buy-out is valid and acceptable, but according to the Iranian Football League’s new charter of registration of employment contracts for the season 2023-2024, the use buy-out clause in the contract of Iranian players is prohibited. The findings of the present study with the analytical-descriptive approach indicate that the nature of the buy-out clause is a conditional opt-out right. Termination by this method should be deemed to be based on the parties’ (prior) consent. The player can trigger the buy-out clause and terminate his/her contractual relationship unilaterally and prematurely upon the unconditional and complete payment of the buy-out fee.