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Background and Objective: In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production. Materials and Methods: Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA. Results: The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl2 of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl2 (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester. Conclusion: The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of‌ biogas.

The main objective of this study is to design and construct the new, spouted bed dryer, for food drying sensitive foods specially. For this purpose, firstly a new design of dryer was planned to achieve the maximum efficiency and flexibility for liquids and solids drying. After constructing and initial setup of spouted bed, basic experiments such as investigation of an inert particles motion, pressure drop, energy consumption were conducted and optimal system requirements for two particle size (5.8 & 7.8 mm) were determined. The results indicated that changes in pressure drop in the dryer chamber containing inert particles are followed from the Ergun equation. Energy consumption in this system is variable in the range of 3-8 kW per hour. Also results reveals that the energy consumption of the new design of spouted bed dryer is less than the spray dryer for liquid foods drying.

According to the importance of expanding the use of clean energy, especially solar energy, in this study a solar cooker was designed, built and its performance in terms of the angle of the side mirrors at the same time and working time on the amount of energy absorbed was investigated by response surface methodology (RSM). The total amount of solar radiation as a measure of energy intake and increased water temperature inside the container was taken as an indicator of the amount of energy absorbed. The model on the basis of response surface methodology was used to validate the test and had a good validation (R2=0.89, R2adjusted=0.74 and lack of fit: no significant). Analyzing the results of a mathematical model was obtained for investigation of the effect of the side mirrors angle and time on the performance of the system. The amount of absorbed energy by theory and laboratory has been also compared and the average of error at all tests was 2.75%. Based on this model in the optimal condition, energy absorption was increased by 22.56%. This study was done at Institute of Food Science and Technology located in Mashhad with latitude 54 and 36 degrees and a height of 985 meters above sea level.

Thunder and storm fluctuations as consequences of climate change were studied in the Caspian region over the last half century. In this study, whole forest areas in southern part of Caspian sea were monitored by study on vegetation map and field visit. Three points representing the major part of the Hyrcanian forests were selected from wet part in the west to drier part in the east. Four meteorological stations data used for investigation. Most of climatic factors including maximum, minimum and mean annual temperature; daily, monthly and annual precipitations were investigated. Numbers of days with thunder and storm as well as wind speed were used for conclusion. During last half century, as consequence of climate change by means of increasing temperature and changing precipitation trends, number of Days With Thunder and Storms (DWTS) increased in forest area in the Caspian region. In Rasht and Gorgan stations, the number of days with thunder and storm in last half century, especially in last 25 years showed a sharp increase. This is in the same line of increasing mean annual temperature about 1.28°C and minimum temperature about 2.45°C in Rasht station. In addition, it is against the decrease of precipitation for the period of last 53 years in Gorgan station which is about 55.6 mm. Anzali and Baboulsar stations which are under coastal climate condition have a fluctuating trend of DWTS but also showed a mild increase in the trend of DWTS during last fifty years. This is in favor of increasing the mean annual temperature in Baboulsar station in last 54 years, about 1.44°C and its minimum temperature about 1.80°C. Also again, it is against the decrease of annual precipitation in Anzali station during last 54 years of records, which is about 409.4 mm and amount of the decreas of precipitation for the period of last 53 years in Gorgan station is about 55.6 mm.

Caspian Sea is one of the most low-lying areas of the region which is located between latitudes 36.34 and 47.13 degrees north. Its considerable vast area and depth have provided an opportunity to gain renewable energy by different methods. This paper analyzes the performance and mechanism of a floating wave energy converter known as WaveStar, in the above-mentioned sea. Different parts of mechanism are examined under hydrodynamic forces of waves with certain periods and amplitudes. By using the frequency parameters, profile and velocity of the waves; and solving the governing dynamic equations for the model, the vibration response of system has been derived. The main part of this study is the investigation of the effect of changing the arm length, float diameter, wave period and wave amplitude on the structure using regular wave with Froude-Krylov force.

Background and aims: Fossil fuels Emission and their limited resources make to use renewable energy with more sustainable energy sources and less minimal environmental impacts. One of the most appropriate renewable energies considered lots of advantages including being renewable and environmentally friendly and containing social and economical interests, is Biomass. “Biomass” means a power source that is comprised of, but not limited to, combustible residues or gases from forest products manufacturing, waste, byproducts, or products from agricultural and orchard crops, waste or co-products products from livestock and poultry operations, waste or byproducts from and food processing, urban wood waste, municipal solid waste, municipal liquid waste treatment operations, and landfill gas. Due to the wide availability of biomass worldwide, mainly because it can be obtained as a by-product of many industrial and agricultural processes, biomass represents a growing renewable energy source with high growth potential. Biomass helps reduce the amount of GHG that give more impact to global warming and climate change. The biomass emissions level is far smaller compared to fossil fuels. The basic difference between biomass and fossil fuels when it comes to amount of carbon emissions is: all the CO2 which has been absorbed by plant for its growth is going back in the atmosphere during its burning for the production of biomass energy. While the CO2 produced from fossil fuels is going to atmosphere where it increases greenhouse effect. Another great advantage of biomass energy is that it is an indigenous fuel. The fuels from biomass materials can be produced locally and no high technology is required. Producing fuel from biomass materials reduces the dependence of a country on foreign resources for their fuel requirements. Moreover, since this indigenous fuel is labor intensive, it can contribute to the generation of new jobs, particularly in rural and farming communities. The number of employed workers required is 3-6 times greater than the fossil energy production in the associated processes. This study was aimed to identification and green grading of environmental management in that’s jobs. Some other socio-economic benefits can be counted such as slowing down the migration from the rural areas to cities, decreasing the issues associated with rapid urbanization, and developing a biodiesel production industry. Among its great benefits is the forest use of the territory, which would also serve to clean the forest and thus prevent forest fires, and the ability to generate jobs. Biomass generates continuous employment such as the extraction of raw materials from the countryside and the bush. This study was aimed to identification and green grading of environmental management in that’s jobs. The research questions are: 1. What are green job indicators? and 2. has renewable energy biomass business indicators of green jobs? Methods: This study was qualitative – quantitative, first according to the grounded theory qualitative method semi-deep interviewed with 50 environmental experts in the Environmental Protection Agency, the municipality, faculty members of the universities, the natural resources and watershed management, agriculture ministry and NGOs active in the environment conducted a with purposeful sampling (snowball). Regarding qualitative data validation were used constant data comparison, reviewing the observers and handwriting by participants and use of foreign and expert researchers familiar with qualitative research as an observer. Then, data was analyzed using the grounded theory of open, axial and selective coding analyzed in MAXQDA software. Once coding categories emerge, the next step is to link them together in theoretical models around a central category that hold everything together. In order to explain the grounded theory, green jobs are considered as the central variable, and the main line of research is defined using reminders and diagrams around it, and finally the green indicators derived from it are developed. Based on them, researcher-made questionnaire was designed in a combination, closed response with 5-rate likert scale. In order to determine the validity of the questionnaire, the content validity was used with the lawshe model and with reviewing previous studies was determined, the scope of the questionnaire in greenness of the job, and the reliability of the questionnaire was obtained using Cronbachchr('39')s alpha coefficient for internal consistency. Cronbachchr('39')s alpha value for each research question was more than 0.7, the reliability of the questionnaire was approved. Also, the Cronbachchr('39')s alpha coefficient of the questionnaire was 0.890. In order to estimate the repeatability, the retest method and the ICC index were used that index was 0.996 (p <0.001), indicating its high repeatability. For estimating the results of greenness and its degree in the jobs of renewable energy biomass, were used statistical analysis of Kolmogrov-Smirnov test, single-sample t-test and Friedman test in SPSS software. Result: Findings of the qualitative research on the structure of green job identification and prioritization were discussed in six categories including establishment in accordance with the legal and technological infrastructure of the green job as context, green job as a phenomenon, environmental pollution elimination and the health risks reduction of the community as causal conditions, green management as operational strategies, environmental empowerment of jobs as an intermediary conditions and economic and environmental benefits as a consequence. The results of quantitative to showed that jobs studied are considered green jobs and their green grading are as follows: 1. Maintenance (mean=5/61), 2. System Design (mean=4/83), 3. Training (mean=4/22), 4. Quality Monitoring and Quality (mean=4/03), 5. Collection (mean=3/64), 6. Manufacturer (mean=3/61) and 7. Worker and System Administrator (mean=2/06). According to the results, components of green jobs are defined including: (1. explaining Green Jobs, Productivity of Occupations, 2. environmental Protection and Health, 3. Green potentials and incentives, 4. environmental Standards and Indices of Health and Green Management, 5. environmental and health challenges and solving energy crisis with the help of green jobs, 6. environmental education and green culture, 7.environmental empowerment through a variety of environmental and health education, informing and accompanying NGOs, 8. economic-ecological profitability and the optimistic approach to economic interests (green economy) and impact of economic issues, profitability, financial support, market regulation, and return on investment in the process of greening and green expanding businesses). Results show that green indices of occupations are 1- environmental and health of profile occupational, 2- strengths and weaknesses, threats and opportunities green jobs, 3- green supply chain management of businesses, 4- impact of green jobs on sustainable development and community health, 5- effect of environmental education on the green performance of occupations, the impact of environmental advertising on green performance and 6- reduce employee costs and increase business profits through environmental management. These green jobs literature extols the virtues of generating energy using “wood waste and other byproducts, including agricultural byproducts, ethanol, paper pellets, used railroad ties, sludge wood, solid byproducts, and old utility poles. Several waste products are also used in biomass, including landfill gas, digester gas, municipal solid waste, and methane. Conclusion: The green features of the biomass business are included solving the problem of fossil fuels, caused by fossil energy and renewable energy sources. identification and green grading jobs diversifying energy sources, sustainable development, securing energy, removing environmental and health problems would help to managers and policy makers for identifying and providing executive solutions and identifying multifaceted priorities for green management. Despite the high potential of bio-economy in renewable energy (biomass) and high amounts of raw materials in the agricultural waste and sewage has not been fully realized. To achieve of developing a competitive economy, low-carbon resources with efficient resources, global economic markets have shifted strategy towards renewable energies, so as to create green jobs in order to reduce environmental problems (waste and climate change). For performance of macroeconomic policy in notification Supreme Leader on the restructuring of the countrychr('39')s economic structure has proposed policies to change reducing dependencies on fossil fuels and external resources towards the creation and development of green jobs in the field of renewable energy, especially biomass, because there are a lot of raw materials in the country, especially in the villages and without necessary to high technologies. Biomass development increase energy efficiency, the use of renewable energy resources and the creation of a favourable environment for investment in energy efficiency measures and the generation of ‘green’ jobs. The rural development prospects for green job growth are mixed. Rural areas contain biomass feedstocks which will be increasingly relied upon to offset fossil fuel dependencies. The distribution of those feedstocks, however, is not uniform across rural areas. Furthermore, the technologies to convert those feedstocks into fuels and other uses are yet to be demonstrated at commercially successful scales. Both policy development and research activities should be focused on the efficient utilization of rural natural resources, human capital, and rural infrastructure in achieving national green policies. The green economy appears to be fertile ground for unbiased, academic research to examine some of the regional consequences of green jobs growth and green jobs policies, to include an examination of rural opportunities, but going well beyond that dimension to include the integration of statewide and multi-state regional development opportunities as well as consequences. This study was not about raw materials (waste and sewage) to produce renewable energy biomass, and it is possible that this section may also be effective in the creation and development of green jobs, then there may be restrictions on the generalized findings, interpretations, and attributes of the causation of variables. Therefore, it is suggested that future research into this part of the process of producing renewable energy biomass should be considered.

Background and aims: Providing the adequate flow and water pressure in the firefighting network of the power plants requires the proper design and analysis of the firefighting system. This study aimed to model and hydraulic analysis the fire network in a combined cycle power plant to determine the network efficiency in the extinguishing of the possible fire. Methods: In the present study, the amount of water needed for firefighting network was estimated for different sections of the power plant according to NFPA standard. Then, based on general piping maps, isometric, and technical specifications of the site, network modeling was done using WaterGEMS software. Finally, the network efficiency was analyzed to provide flow and water pressure in three possible scenarios. Results: The results of this study showed that the network and pumping station could provide pressure and water flow for cooling and foam production to extinguish the small and medium-sized fire. In special circumstances and with the occurrence of extensive fire, such as the advent of fire in all fuel tanks, the pressure in the network is reduced to 3.6 bar and the pressure to extinguish, spray water, and the foam is not supplied. In other words, the system will not have acceptable performance in large fire extinguishing. Conclusion: Hydraulic modeling of the fire network using WaterGEMS software, in addition to identifying the defects of the fire extinguishing system, it can provide the ability to analyze and design the network to deal with the consequences of fire in industrial environments during crisis situations properly.

The energy management of ships to improve the efficiency of ships and reduce greenhouse gas emissions is among the most important issues that have been considered as a milestone in designing and constructing of vessels in recent years. The study of energy trends and attention to technological changes and the importance of more stringent environmental standards in recent years have led to a major challenge in relation to air pollution, energy management, and exposure to end-of-life sources of fossil fuels. In recent years, focus on current fuels and technologies in vehicles has led to a major challenge regarding air pollution, greenhouse gas emissions, energy security, and also exposure to exhausting sources of fossil fuels. Now days, Hybrid propulsion systems are one of the solutions that are being followed in many countries to solve this problem. In this paper, after introducing the hybrid system; conceptual design and determination of a suitable hybrid system for vessels have been investigated. Then the calculations and relations dominating the hybrid parallel system of vessel are presented. The modeling is also done using the ADVISOR software run in the Simulink platform of the MATLAB for both conventional and hybrid systems. The results show that parallel hybrid vessel has improved by 7% in total efficiency and 7.1% for consumption. In addition, HC and CO emissions have been decreased by 0.44% and 0.39%, respectively.

Introduction: Identification of degrading microorganisms of toxic materials is regarded as an important step to complete air treatment systems. Effective microorganisms in treatment and elimination of pollutants seems to be different depending on the type of pollutants as well as environmental conditions. Identification of these microorganisms can determine optimum conditions for the system performance and the maximum efficiency can be reached. Moreover, biotechnological methods can strengthen the microorganisms to treat the pollutants. This study aimed to identify the predominant microorganisms at two biotrickiling filters that formaldehyde was used in one and ethanol in another as the sole carbon source. Methods: In this study, two biotrickling filter pilots were made at the laboratory scale. These microorganisms were inoculated and adapted within three months. Then biotrickling filters were studies for a long time. At the end of experiments, biofilm samples were taken from biotrickling filters and predominant microorganisms were identified via microbiology studies. Results: The results of the present study managed to identify such microorganisms as Salmonella Bongori, Pneumonia, Subspecies Pneumonia, Klebsiella Terrigena, etc. at different parts of both biotrickling filters. Conclusion: Microbial species can be widely changed with operating of biotrickling filters at different conditions. Identifying active microorganisms in each biotrickling filter can lead to detecting optimum conditions as well as the risks caused by transfer of the filters' available microorganisms to the human body .

The marine and ocean energies are part of renewable energy that Wave energy converters (WECs) are used to extract them. Experimental modeling will be useful in evaluating their performance. In this research, the experimental model of an attenuator WEC is built in the Sea-Based Energy Research Group of the Babol Noshirvani University of Technology, and its performance is studied and evaluated in the wave tank of the university by applying the sea waves conditions. In this evaluation, the effects of wave amplitude and wave period on the average and maximum net power of the Wavestar system are investigated. According to the results, it was observed that in larger wave amplitudes (13 to 15), at 35 and 25 rpm, the maximum net power was close to each other and was 36.7 (Watts) and 31(Watts), respectively. Due to the irregular wave and possible damage to the system at 35 rpm, the wave amplitude of 15 and the speed of 25 rpm are chosen as the optimal mode for better performance of the system.