Fossil fuel consumption problems and water crisis are serious dangers. Using renewable energy is a solution to reduce fossil fuel consumption. Photovoltaic is a renewable energy generation method which is abundantly used all over the world. By installation of solar panels on the surface of water, the efficiency of panels increases and in addition, the surface evaporation of water will be reduced. Dams are one of the main sources of water. In the present study, installation of solar panel on surface of the Tanguie dam is studied from technical point of view. The generation PV power is used to produce hydrogen by electrolysis process and consume it in PEM Fuel cell to decreases the peak load. Results show 2.6% increase in panel efficiency when they are installed on water. And this increase in efficiency causes that 360780 installed panels generate 4 million kWh additional electricity power in the year. As well as, covering 678628 m2 of dam with these panels prevent from 1.97 million m3 water evaporation in the year. Also, the generated PV power could supply about 99% of load which is above 90MW.
Considering increasing population growth in recent decades, and consequently, the increase in waste production in the world, waste management and efforts to reduce their harm to the environment has become an important issue. One of the appropriate ways to manage municipal waste is to generate energy from waste, especially by RDF production method. On the other hand, in order to reduce the consumption of fossil fuels in various industries that cause environmental pollution, alternative fuels have become one of the key issues among environmental researchers, for instance providing new fuels with less pollution to cement production plants which use coal as main fuel is increasing. In the present study, the feasibility of producing RDF as an energy supplier in cement factories has been evaluated. For this purpose, in 6 consecutive days, the wastes were collected from Qazvin city and physical and chemical analysis were performed on them. By using the proposed equations, the heating value of the existing waste is calculated. The results show that the heating value of RDF products from wastes is about 9100 Kj/Kg in summer and 9500 Kj/Kg in autumn, about thirty percent of coal heating value. Also by removing food wastes and using the five main RDFs material including paper, cardboard, plastics, PET, textiles, and wood, there will be a significant increase of heating value about 110% compared to the presence of food wastes.
Recently, in most of the condensate tank production projects, two main activities of welding and painting are done in manual and automatic ways. The purpose of this study is green supply chain management of these activities in order to select the best production method. For this purpose, by literature reviews and using Delphi and DEMATEL techniques, the indicators and sub-indicators of green supply chain of condensate storage tanks and their internal relations were identified. The indicators were weighted and ranked by ANP method. Ultimately, the best way to build condensate storage tanks was determined. Among the 8 main indicators and 35 sub-indicators, âfinancial riskâ was recognized as the most influential indicator and categorized in the cause group. The âreverse logisticsâ was found to be the most effective indicator and classified in the effect group. The âenvironmental managementâ was the indicator engaged in most interaction with the other factors. Overall, the environmental management indicator, with a weight of 0.35172, ranked first and âsupply riskâ indicator, with a weight of 0.00357, was recognized as the least important indicator. The strategy of âautomatic painting and welding of large tanksâ, with a weight of 0.21537, was selected as the best construction method of the tanks. The results showed that, by the integrated use of DEMATEL and ANP methods, more accurate ranking of options would be achieved.
The portfolio optimization is one of the fundamental problems in asset management that aims to reduce the risk of an investment by diversifying it into assets expected to fluctuate independently. A portfolio is a grouping of financial assets such as stocks, bonds, commodities, currencies and cash equivalents, as well as their funds counterparts, including mutual, exchange- traded and closed funds. A portfolio can also consist of non-publicly tradable securities, like real estate, art, and private investment. This paper aims to study stock portfolio investment problem with pythagorean fuzzy numbers. After converting the problem into the corresponding crisp based on the score function, a solution procedure is suggested to give the decision of the portfolio investment combined with investors in savings and securities. The advantages of this study are: The investor is freely to choose the risk coefficients enable him/ her to maximize the expected returns; also he may determine his/ her strategies under consideration of his/ her own conditions. An example is introduce to clarify the practically and the efficiency of the technique.
Companies are faced with serious challenges in environmental and economic crisis. It may become a threat to their ï¬nancial performance and viability. Thus, there is an urgent need for being resilient in the event of any disruption. The present study aims to assess the performance of companies listed in Tehran Stock Exchange in terms of resilience factors. A standardized questionnaire containing resilience factors is designed to collect data from managers and staff. The effect of resilience factors on performance in the crisis period is examined by data envelopment analysis (DEA) method. It is observed that performance is greatly affected by management commitment, awareness, self-organization, and competitiveness and an improvement in them enables the companies to be more resilient during environmental and economic crisis period. An integrated approach to the performance optimization of companies is first developed. It may be a useful framework for any type of company to identify the most important resilience factors in economic crisis.
The purpose of the present study is to identify the effective factors in citizen participation in waste generation and waste separation and their scientific analysis. In order to accomplish this goal, using descriptive-inferential research method, information was collected by documentary method. The statistical population of the study consisted of the citizens of two districts of Tehran 8 and 12, which had the highest and the lowest participation in separation of waste source, respectively. Data were analyzed using relative frequency tables, Likert verbal scale, Kruskal-Wallis non-parametric test and correlation test and regression method. The results of hypotheses test indicated significant relationship between variables of age, level of education, occupations, average monthly income, number of households, citizen education and awareness, and participation rates. Also the results of Kruskal-Wallis statistical test showed that there is a significant relationship between gender and participation, but the relationship between housing ownership and participation is not significant.