mohsen soleymani

In order to investigate the effect of soil moisture and air transfer tube lenth on the performance indicators of a geothermal system, two factorial experiments were conducted based on a complete randomized block design in three replications in a greenhouse equipped with Earth–Air Heat Exchanger(EAHE)system located in the city of Arak in early August and September 2022. Two soil moisture levels, a1=10% and a2=25%, were considered as the first factor and three pipe lengths of b1=17, b2=34, and b3=51 m, were considered as the second factor in both experiments. The air was circulated by a fan through two PVC pipes with a diameter of 200 mm, which were buried at three meters deep from the ground surface. An irrigation tape with a diameter of 16 mm was used to increase the soil moisture around the pipe. The results showed that with the increase of soil moisture from 10% to 25%, the temperature of the outlet air decreases from 25.5°C to 23.5°C. The average efficiency at soil moistures of 25% and 10%, was 0.82 and 0.69 respectively. The produced cooling power was 2.7 kW and 2.2 kW, at two levels of soil moisture respectively. The best treatment from the point of performance indicators was obtained with a tube length of 34 meters and soil moisture of 25%. The outlet air temperature, system efficiency , cooling power and coefficient of performance for this treatment were 23.7°C, 0.90, 2.8 kW and 3.7 respectively.

Hur al-Azim wetland in the southwest of Iran has become one of the major sources of air pollution in Khuzestan province in recent years due to widespread fires. Sustainable harvesting of this huge source of biomass and controlled combustion, in addition to reducing current pollution, can play an effective role in sustainable renewable energy production. Therefore, in this study, it is tried to estimate the amount of sustainable harvestable biomass from this wetland. In order to identify and estimate biomass amount, NDVI index was used in satellite images. Also, by visiting 30 points with different NDVI index, and harvesting biomass, yield per hectare was estimated. Also, the thermal characteristics of the reed plant were investigated for use in a biomass burning power plant. Based on the results of the estimation, approximately 3,500,000 tons of reeds can be harvested annually from the total of 33,712 hectares of reeds in the Iranian part of Hur al-Azim wetland, and according to the average biomass moisture (65%), the amount of dry biomass that can be harvested annually will be about 300 thousand tons, which is a very significant number. Also, according to the results, the calorific value of the reed plant (about 20 MJ/kg), the amount of ash, the composition of the ash, as well as the composition of the elements of the reed plant organs are comparable with reference energy plants, which makes it possible to use as a fuel in biomass power plants.

Anaerobic digestion, in addition to producing biogas, can minimize the environmental problems of animal manure and produce high-quality fertilizer. Finding suitable places for the construction of anaerobic digestion reactors is essential for the sustainable development of these types of power plants. Locating the biogas production site is a complex process with different and sometimes contradictory criteria including environmental, economic and technical criteria from which the location-related factors play the main role. The integration of geographic information systems (GIS) with multi-criteria decision making (MCDM) provides a powerful tool that can be useful in locating biogas power plants.

In this study, spatial and non-spatial data were integrated with geographic information system in order to determine the optimal places for installing anaerobic digesters of livestock and poultry waste in the southeast of Khuzestan province. Data related to the type and number of livestock and poultry were collected separately from the Ministry of Agriculture. The location of livestock farms and chicken farms was determined using the GPS system. Livestock and poultry raised in the traditional way in the villages were not taking into account due to the problems of collecting manure and lack of economic justification. In order to determine the evaluation criteria and score them, similar studies, rules and guidelines, as well as the Delphi technique were used. 14 sub-criteria were evaluated in three main environmental, social-safety and topographical groups. Land suitability layers for the construction of anaerobic digestion reactors were prepared from the perspective of all sub-criteria in the GIS environment. In order to simplify calculations and easier weighting of criteria and sub-criteria to obtain the final result, some layers of criteria were combined. In this way, 14 layers were combined and overlapped until 7 layers of final criteria were formed. Since the spatial potential layer of biogas production is the main criterion and has the main effect on the suitability of land for the construction of a power plant, and on the other hand, it has no essential relationship with other criteria, it was valued separately. Roads and residential areas were also valued separately due to the greater importance of lower transport costs, accessibility, reducing transport time and losses, as well as environmental, health and safety impacts. The overall layer of surface water was obtained by multiplying the four layers of land suitability considering the sea, river, wetland and flood prone areas. Sensitive areas including forest, agriculture and protected areas were also considered in an exclusive layer. The other two layers were the combination layer of slope, height and fault, and the combination of railway lines and high voltage power lines. These layers were weighted using pairwise comparisons and hierarchical analysis method. The final layer of land suitability for the construction of anaerobic digesters and power plant was created by overlapping all the criteria layers based on the obtained weight.

The findings showed that anaerobic digestion of livestock and poultry wastes in the region has a potential to produce 7.25 million m3/year of biogas. Cow and chicken excrement have the largest share with 51.32 and 29.34 percent, respectively. The restriction layer showed that 73.28% of the area is unusable due to one or more restrictions. The results also showed that "regional biogas production potential" and "access to roads and energy consumption centers" are respectively the most effective factors in determining the appropriate location for the power plant. Finally, using spatial analysis in ArcGIS environment, the studied area was classified into five suitability levels: "unsuitable", "weak", "moderate", "suitable" and "very suitable". Based on this, 73.28% of the studied area was completely unsuitable and only 1.68% of the studied area was very suitable for the construction of a power plant.  But in almost all the studied areas, there was enough land with suitable or very suitable conditions to build a biogas plant.

In the studied area, lands with suitable conditions for the construction of a power plant from animal waste using anaerobic digestion technology were identified. There is a suitable distribution of "suitable" or "very suitable" levels in the study area for the construction of a biogas power plant. The findings of this study can be a guide for those in charge to make a decision for the construction of a power plant.

The spread of the corona virus has caused the closure of face-to-face education and the forced transition of the country's education system to virtual education. After two years, when virtual education has gradually ended and face-to-face education has been established, it is necessary to study the challenges and problems of virtual education from the perspective of teachers as the main pillar of education. This research has been done with the aim of studying the challenges of virtual education and evaluating teachers of this style of education. This study was conducted in the framework of a qualitative approach and with the phenomenological method, in which data was collected using a semi-structured interview. The interviewees were 12 elementary school teachers in Tehran who were selected through purposive sampling and the interviews were continued until theoretical saturation was reached. The findings of the research showed that teachers' perception of the challenges of virtual education includes 4 main themes and 19 sub-themes, which main themes include material and technological challenges, challenges of education governance, challenges of the hidden elements of education, and challenges of the teacher training system.

The effect of biodiesel percentage in biodiesel-diesel blends on the engine under different engine operation conditions must be predicted to achieve high performance. The goal of the present paper was to model brake power, brake torque, thermal efficiency, and specific fuel consumption of a diesel engine fueled by algal biodiesel-diesel blends. The response surface methodology was successfully applied to model the performance indicators of biodiesel-diesel fueled OM 314 diesel engine at various engine loads and rotational speeds. Brake power, torque, and thermal efficiency increased by increasing engine load. Increasing engine rotational speed caused increase in brake power whereas highest brake torque and thermal efficiency was obtained in medium engine rotational speed. Increase of biodiesel percentage caused decrease in. Biodiesel had negative effects, but it had lower effects than engine load and rotational speed on the change of the engine performance indicators. Brake specific fuel consumption decreased by increasing load but it was lowest in medium rotational speeds. A quadratic model was suitably fitted to predict the effects of input-output variables with statistical significance of 1% probability level. The coefficient of determinations for prediction of the engine brake power, brake torque, thermal efficiency, and brake specific fuel consumption were 97.63, 99.74, 97.41, and 95.72%, respectively. The result of the present work is useful to find optimum biodiesel percentage and engine load and rotational speed to achieve high performance fuel blends.

In recent years, due to its availability and low environmental pollution, the use of Earth-Air Heat Exchanger (EAHE) has been developed as an efficient energy system in heating and cooling residential buildings and agricultural greenhouses. In this system, air is circulated by a fan through a pipe buried deep in the ground. Depending on the geographical location and soil type, the soil temperature at a depth of 2-3 meters remains unchanged throughout the season. Of course, this depth varies throughout the year and according to climatic changes. The heat exchange between the soil and the air inside the pipe depends on the type of soil and its moisture content, the length and diameter of the air transmission pipe, the depth of burial and the velocity of the air flow (air velocity). Air circulation can be done in an open-loop or closed-loop circuit.

A factorial experiment was conducted in the form of a completely randomized block design with two factors (pipe length at three levels (34, 17 and 52 meters) and air velocity at two levels (5 and 10 m/s)) in three replications, to investigate the effect of these factors on the coefficient of performance (COP), system efficiency and outlet air temperature. The experiment was conducted in a greenhouse in Arak city, Iran, in Joune 2022. This 150 square meter greenhouse was equipped with geothermal equipment. Air was circulated through a 200 mm diameter PVC pipe buried three meters deep in the ground. Air was circulating through an open loop circuit. Dependent variables were measured during the hot hours of the day (from 12:00 to 18:00) for one week at the end of July. The air temperature at the fan inlet and at 17, 34 and 52 meters along the pipe was measured by a single-channel data logger. Hourly changes in outlet air temperature, COP and efficiency were measured in a 24-hour period and plotted using Excel software.

The outlet air temperature for the pipe length of 34 and 52 m did not change when the air velocity decreased from 10 m/s to 5 m/s. But for the pipe length of 17 m, the maximum temperature, COP and efficiency were observed at an air velocity of 5 m/s. Regardless the air velocity, the average temperature of the outlet air for the three levels of the pipe length was 28.5, 25.5 and 25.3°C, respectively. The outlet air temperature was almost the same for the 34 and 52 m pipe lengths. In other words, the optimal length of the pipe is about 34 meters. The mean efficiencies for these two pipe length levels were 0.69 and 0.66, but the COP depended on the air velocity. The average COP for air velocity of 5 and 10 m/s was obtained 1.4 and 2.5, respectively. Based on these results, the best performance of the system in terms of output temperature reduction, cooling efficiency and COP is obtained in situation that the length of the pipe is 34 m and the air velocity is 10 m/s. when the length of the pipe is 17 meters, the temperature of the air outlet at two velocities of 10 and 5 m/s was 29.9 and 27 °C, respectively. The cooling efficiency and COP at two velocity of 10 and 5 m/s, were 0.34, 0.54; and 2.1, 1.7 respectively. If the desired temperature is 28-30 °C, pipe length of 17 m and the air velocity of 5 m/s is recommended. The results of hourly performance analysis showed that the highest difference between inlet and outlet air temperatures, is obtained at middle hours of the day. The higher the ambient temperature, the higher the efficiency of the EAHE system.

This system successfully met the cooling needs of a model greenhouse in the weather conditions of Markazi Province in June. Based on the results, the optimal pipe length and air velocity were obtained as 34 m and 10 m/s, respectively. The average air outlet temperature and cooling efficiency were 25.5, 0.66 and 2.5 respectively. The higher the ambient temperature, the higher the EAHE efficiency. This is mainly due to the higher temperature difference between the outgoing and incoming air during the hottest hours of the day. As a result, system efficiency and COP increase at the hottest hours of the day.

Rice is one of the most important summer crops that is harvested in recent years by combine harvesters with different mechanisms. In this study, the amount of quantitative and qualitative losses of Champa cultivar in Ramhormoz city was evaluated by different combines. This research was conducted in a randomized complete block design with the method of split plots. The main plots were the crop moisture at harvest time included three levels: 19-21 percent (M1), 21-23 percent (M2) and 23-53 percent (M3) and the secondary plots were the combine types included four levels: cereal combine, with raspbar thresher (C1), cereal combine, with spike type thresher (C2), rice combine, World model, with spike type thresher (C3) and rice combine, Chery model, with spike type thresher (C4).The results showed that quantitative and qualitative losses related to moisture were significant. In terms of moisture the lowest and highest total quantitative losses obtained in M2 with 3.60 percent and in M1 with 3.87 percent, respectively; and the lowest and highest total qualitative losses obtained in M3 with 1.37 percent, and in M1 with 3.01 percent, respectively. Also, all the different components of quantitative losses, except for the head section, as well as the various components of qualitative losses related to the type of combine were significant. In terms of total quantitative losses, the lowest and highest values were belonged to C3 with 2.97 percent and C1 with 4.83 percent, respectively, and in terms of qualitative total losses, the lowest and highest values were belonged to C4 with 1.32 percent and C1 with 3.99 percent, respectively.

Desertification is currently a problem in many countries of the world, including developing countries. The result of this phenomenon is the loss of renewable resources in each of these countries. One of the most important renewable sources is water, which is polluted in various ways today. Nitrate and phosphate are two important pollutants that are created by chemical fertilizers and pollute the environment, including water sources, and have harmful effects on human health. Sulfates are also another major ion found in natural waters and wastewater. There are common physical, chemical and biological methods in removing these pollutants from water sources. Due to the high cost and limited efficiency of physical and chemical methods, in recent years, suitable and inexpensive natural treatment methods such as Phytoremediation has been studied. The phytoremediation process is a natural way to purify contaminants that is very effective and inexpensive and can be performed for a long time. Due to the limited quantity and quality of water and soil resources and the need to provide food for the growing population of the country, today special attention has been paid to the production of agricultural products in soilless cultivation systems. Therefore, due to the fact that plants have different abilities in monitoring pollution, suitable plants should be used to clean polluted environments. Eucalyptus camaldulensis Dehnh. and Elaeagnus angustifolia L. plants are among the common and well-known species in Iran for planting along waterways with the aim of purifying crop water to prevent them from entering surface flows.However, as far as the comprehensive studies of the researcher in internal and international sources show, no study has been done on the removal of nitrate, phosphate and sulfate by Elm and Eucalyptus., this research can be the first research in this field to purify polluted resources in Iran. The present study was conducted in the greenhouse of Isfahan University of Technology at a temperature of 40 degrees. In First, to study and compare phytoremediation of nitrate, phosphate and water sulfate using Eucalyptus camaldulensis Dehnh. and Elaeagnus angustifolia L. tree species. seedlings of these trees were planted in plastic pots with a cover of washed pebbles. Overall, The pots were 54 and had a volume of about 10 liters and a diameter of 12 cm. Thus, in 27 pots of Eucalyptus and 27 other species of Elaeagnus were planted. At the beginning of planting, the seedlings were impregnated with hydroponic solution (with a volume of 2 liters) and about 2 times a week, hydroponic solution was added to each pot. after establishment of plants, solutions containing nitrate, phosphate and sulfate prepared in the laboratory was added to the culture in three replications with concentrations (0,30,60 mg /l) for phosphate and sulfate and concentrations (0,50, 100 mg /l) for nitrate. Three chemicals, potassium nitrate KNO3, monosodium phosphate NaH2PO and sodium sulfate Na2SO4 , were used to prepare nitrate, phosphate and sulfate contaminants, respectively. This experiment was performed for four months in the natural resources greenhouse of Isfahan University of Technology in March 2017. The experiment was performed factorially and in the form of a completely randomized design. In order to measure the nitrate, phosphate and sulfate of the samples and evaluate the effect of phytoremediation on the uptake of these contaminants, samples of the culture medium were transferred to the laboratory every month with contaminated water. Data were collected and recorded for at least 3 months and the uptake of nitrate and phosphate in the leaves of the plant was examined by sampling and analysis in the laboratory during each month. Plant parameters were harvested every week. In this regard, the effect of different concentrations of nitrate and phosphate contaminants on some physiological factors of the plant (stem diameter, plant height, stomatal exchange and chlorophyll content) were measured. also all data were measured by statistical analysis using SAS statistical software with version 25. Finally, analysis of variance was performed by ANOVA test and mean data were compared by LSD test. The results of the analysis of variance, for nitrate, phosphate and sulfate removal showed a significant difference at 99% level. The results of analysis of variance showed the highest percentage of removal was to Eucalyptus species with 86.26% nitrate, 95.34% phosphate and 86.8% sulfate and to Elaeagnus species with 83.72% nitrate, 88.55% phosphate and 90.73% sulfate. As a result, Eucalyptus specimens showed a higher ability to remove nitrate and phosphate pollutants and Elaeagnus species a higher ability to remove sulfate. The results also showed that the correlation and interaction of species on physiological traits (stem diameter, plant height, Chlorophyll content and stomatal exchange) was very significant due to differences in species and different concentrations of pollutants. Also, the results of mean comparison showed that no significant differences were observed between the traits of Eucalyptus and Elaeagnus species.

The aim of this study was to compare the fertilizer properties of anaerobic digestion residues (digestate) of chicken manure and fresh chicken manure with the aim of benefiting from the produced biogas and alleviating the environmental problems of fresh chicken manure. The study was conducted in a completely randomized design. In addition to the control treatment, experimental treatment groups were Fresh Chicken Manure (FCM), Chicken Manure Digestate (CMD) and Enriched Chicken manure (ECM), each at three levels and with 3 replications. A total of 30 experimental pots were used for soil treatments and wheat planting. At the end of the growing season, soil variables including nitrogen, organic carbon, absorbable phosphorus, and pH, and physical properties of wheat including dry weight of shoots, seeds and roots were measured. The results were analyzed using SPSS statistical software. CMD application relatively increased soil nitrogen, organic carbon and phosphorus, kept the soil pH neutral, and improved wheat yield components. Compared to FCM, not only has the quality of CMD as biofertilizer not decreased, but it has also improved in some respects. CMD is superior to ECM in all studied indicators. The results are also better or at least equal in comparison with FCM. Due to the environmental benefits of anaerobic digestion of chicken manure and also the production of biogas as a valuable product and proving that the quality of the resulting fertilizer is not reduced, the use of CMD as organic fertilizer has more advantages than the use of FCM and even ECM.

In this study, technical and economical potential of using solar energy for heating cucumber greenhouses in Jiroft region were studied. For this purpose, the climatic suitability of the region was determined. According to the data and thermal requirement of greenhouse, capacity of a flat panel solar water heater was calculated and was compared with the conventional system, gasoil heater. The results of paired t-test showed that there was no significant difference between the two greenhouses in terms of CO2 content, average temperature and relative humidity, but there were significant differences in terms of chlorophyll content and yield between the two greenhouses, at the probability level of one and five percent, respectively. There was a significant difference, with a higher average of conventional system. The results of data analysis in Kamfar software showed that in terms of economic indicators, the use of solar water heaters for heating greenhouses in this area is justifiable in the fifth year and the return on investment is 5.32 years.

In this study, the application of a solar system for heating a greenhouse of twin type with arched structure and single layer polyethylene coating was investigated. For this purpose, initially, the heating needs of the greenhouse were determined. Then, according to the obtained results, a flat-panel solar water heater with a collector of 6 square meters and a tank volume of 500 liters was selected and installed next to the greenhouse cucumber production unit to heat the air inside the greenhouse with 4 unit of 10-blade aluminum radiators. Then, using paired t-test, the results obtained in this greenhouse were compared with the conventional type in the area that had a diesel heater. The results showed that in terms of carbon dioxide, average temperature and relative humidity, there was no significant difference between the two greenhouses, but in terms of chlorophyll index and crop yield, there was a significant difference between the two greenhouses, at a probability level of 1 and 5 percent, respectively. Diesel had a higher average in these factors. Also, managing the four factors of minimum temperature, average temperature, chlorophyll content and maximum relative humidity in the greenhouse equipped with solar water heater and controlling the two factors of minimum temperature and chlorophyll content in the greenhouse equipped with diesel heater can improve photosynthesis and increase yield.

Sugarcane is one of the most important industrial plants in Khuzestan province. With the rising costs of purchasing, maintaining, agricultural machinery, sugarcane agribusinesses have been adopting outsourcing strategies in various sectors, especially in agricultural operations, over the last few years. Considering the importance of three criteria: cost, timely performance and quality in agricultural operations, these three criteria were evaluated in the work of contractor and company labor force in preparation in Amirkabir and Debal Khazaei agribusinesses. To investigate costs, cost information was obtained from the companies studied. The quality of operations was evaluated by field data collection and measurement of qualitative indices. Also, to check the timing of operations, the agricultural operations calendar was compared with actual days of work. Finally, the indices tested (in outsourced and non-outsourced farms) were compared using t-test for independent samples. The most important criterion for land acquisition operations in the agribusiness companies studied is the quality of operations. The results of the comparisons also showed that there is no significant difference between the cost and time of the contractor and corporate force operations but in terms of quality, which is the most important criterion for agribusinesses, contractor workforce outweighs corporate workforce. Therefore, outsourcing operations are for the benefit of the studied companies.

Biogas, a product of anaerobic digestion of biomass resources, is one of the major renewable energies with the potential to replace fossil fuels. Anaerobic digestion is performed under specific conditions and according to a specific chemical process. Sugar cane is one of the most common sources of sugar and bioethanol production in the world. In the ethanol distillation process, large quantities of vinasse are produced. The direct consumption of vinasse as fertilizer has many environmental problems. Anaerobic digestion of vinasse is a potential solution to such environmental problems. Factors affecting the performance of an anaerobic digester can be classified into three main categories: (1) raw material characteristics, (2) reactor design, and (3) operating conditions. Among the operating conditions, temperature and pH are the most important parameters, so in this study, these two parameters were investigated.

The main raw material was vinasse. Some other additives were used to alter its chemical properties. To have a proper substrate composition, the ingredients before loading into the digesters were evaluated for their chemical and physical properties, including pH, concentration and C/N ratio. The bovine rumen contents of 10% of the final volume of input material were added to supply methanogenesis bacteria as well as to modulate the (C/N) ratio. The Total Solid Content (TS), Volatile Solid (VS) and Chemical Oxygen Demand (COD), were evaluated before and after digestion. A series of batch reactor were used to perform the experiment. The experiment was carried out in a split plot design in a completely randomized design. The main and sub-factor was respectively temperature (at four levels of 30, 35, 40 and 45 ° C) and pH (at four levels of 6.8, 7, 7.2 and 7.4), and the experiment was performed in three replication. To measure the volume of gas produced, a 50 ml water tank connected to the digester outlet as a U-tube was used. The amount of water movement in the U-shaped tube is an indicator of the volume of biogas produced. For better detection of water displacement, some color was dissolved in water. Passing the gas produced from the three-molar NaOH solution, its impurities (mainly carbon dioxide) were absorbed, and the resulting pure gas was re-measured using a U-shaped tube. Using the law of complete gases, the biogas volumetric index was converted to the standard gas volume and finally converted to values based on (ml/gVS) and the new values were analyzed by analysis of variance and mean comparison.

Almost all main and interaction effects on all the factors studied were significant at the 1% probability level. The amount of gas produced increased with increasing temperature but with increasing pH, it first increased and then decreased. The amount of gas produced at 35, 40 and 45 °C was not significantly different. So because of economic and energy constraints, an operating temperature of 35 °C is recommended for anaerobic digestion of vinasse. The graph of the interaction of temperature and pH shows that at higher temperatures the rate of gas production increases with increasing pH. Although the highest gas volume was obtained at pH of 6.8 and 7.4, but the gas produced in the pH range of 7–7.2 was more pure. Therefore, the best combination of pH and temperature to produce the highest and purest gas is 7 and 35 °C, respectively. But since the vinasse produced in the alcohol factories has high temperature and therefore higher temperatures are possible, so 40 °C is also recommended. It was also clearly observed that the smaller the volume of gas produced, the greater its purity. The VS-R factor is also more sensitive to temperature changes than to pH changes. Thus, in anaerobic digestion of vinasse, pH control is more important than temperature control. VS-R performs best at pH 7. This factor was not significantly different at 35, 40 and 45 °C. Therefore, considering the cost of providing more heat at temperatures of 40 and 45 °C compared to 35 °C, 35 °C is the best temperature for manure production with the highest volatile organic matter removal. The COD-R process was similar at all pHs. COD-R at pH 7 was higher at all temperatures than at other pHs. It was also significantly higher at 40 and 45 °C, compared to other temperatures. So like other factors, the best pH and temperature based on this factor are 7 and 40 °C, respectively. Conclusion According to all factors studied, the best pH and operating temperature of anaerobic digestion of sugar cane vinasse is 7 and 35 ° C, respectively. Another important conclusion to be drawn from this study is that changes in all parameters studied are affected by pH changes rather than temperature changes. Therefore, sufficient care must be taken to ensure that pH variations in the anaerobic digestion medium be very low and around the range proposed (about 7).

In this study, batch series of laboratory-scale anaerobic digesters at 35 and 55 ° C were used to investigate the production of biogas from dairy effluents and reduce its pollution. Dairy effluent sludge with ratios of zero, 10, 20, 30, 40 and 100% was used for inoculation. The interaction effect of sludge percentage and temperature at the level of one percent on the volumetric indices of biogas production was significant for the amount of initial volatile solids, volatile solids removed and chemical oxygen demand removed at the level of one percent. With increasing sludge percentage, the amount of biogas produced per initial volume increased for the removed COD but decreased for the initial volatile solids. The highest biogas production efficiency was obtained based on the removed volatile solids at thermophilic temperature and 40% sludge ratio, with the removal of 47.7% volatile solids and 266.5 ml per gram of removed volatile solids. According to the results, the amount of biogas production at mesophilic temperature, in lower proportions of added sludge, is more than the amount of gas produced at thermophilic temperature, and due to the low volume of sludge production in the dairy industry and higher energy consumption under thermophilic conditions, anaerobic digestion and biogas production are more favorable at 35 ° C. The results also showed that by anaerobic digestion of each m3 of dairy effluent, 20.83 MJ of heat energy can be produced.

Production and use of biogas, as an alternative renewable fuel, along with increasing energy security, can reduce the use of fossil fuels and thus reduce the environmental impact of these fossil fuels. Biogas production is subject to certain conditions and is influenced by some parameters such as pH, Hydraulic Retention Time (HRT), Solid Retention Time (SRT), temperature, agitation and so on. The existence of a laboratory digester to control and identify the best conditions of these effective parameters is of great importance. Therefore, three types of anaerobic digester, were built to digest liquid wastes, considering the advantages and disadvantages of various digesters, factors affecting biogas production and also considering the cost issues. In these digesters, it was possible to control the parameters affecting biogas production (temperature, pH, concentration and retention time) and were also equipped with a system to measure the amount of gas produced. These digests were batch type and the feasibility of experimental designs to study the effect of parameters affecting biogas production was predicted. Batch digests are more suitable than continuous ones to study raw materials that require longer retention time, such as lignocellulosic biomass. Due to the transparent body of these digesters, it was also possible to study optical treatments. The most important and difficult part of the construction was the possibility of sealing the joints. Glass digester, if properly sealed, is the best one and meets almost all requirements for testing the factors affecting biogas production. Its main problem is the possibility of air leakage and liquid penetration into the mixer electromotor. Due to the flexibility of polyethylene digesters, it is easy to extract air and provide an anaerobic environment. The disadvantage was the requirement of manual or magnetic mixing and a possible error in measuring the volume of gas produced. Use of the Erlen vacuum, rubber cap, needle and heparin locker were appropriately meet the requirements of an anaerobic digester, but steel mixing in the digester is done manually or by magnetic stirring.

Such thermal methods as MicroWave (MW) radiations are considered as fast and efficient approaches in removal of organic pollutants from aquatic and terrestrial environments. This study was carried out to find the optimum conditions for oil removal from contaminated soils treated by MW irradiation. Following soil sampling from Tehran Refinery surroundings, the samples were treated under various conditions for including MW power intensity (770, 1100 and 1250 w) and frequency of 2.45 GHz, time of irradiation (5, 10 and 15 min), soil moisture (1, 10 and 15 % w/w) and added activated carbon (0, 2.5 and 5 % w/w). The optimum conditions of oil removal were obtained from results of Taguchi L9 orthogonal array. Besides, the effect of MW irradiation on some chemical and biological properties of soil was also investigated. Results indicated that the optimum conditions of the investigated parameter ranges were as follows: MW power (1100 w), irradiation time (15 min), soil moisture (1 % w/w) and added activated carbon (5 % w/w). About 70 % of petroleum hydrocarbons were dissipated within optimum conditions. Although the method exhibited some negative effects on respiration and population and respiration of soil microorganisms, still it can be used as an effective and fast approach for remediation of highly polluted soils considering the economic feasibility.

Petroleum compounds are pollutants that most commonly occur in soils around oil refineries and that often find their ways into groundwater resources. Phytoremediation is a cost-effective alternative to physicochemical methods for oil-contaminated soil remediation, where feasible. In this study, a greenhouse experiment was conducted to evaluate the phytoremediation of oil-contaminated soils around Isfahan Oil Refinery. Four different plants (namely, sorghum, barley, agropyron, and festuca) were initially evaluated in terms of their germinability in both contaminated and control (non-contaminated) soils. Sorghum and barley (recording the highest germinability values) were chosen as the species for use in the phytoremediation experiments. Shoot and root dry weights, total and oil-degrading bacteria counts, microbial activity, and total concentrations of petroleum hydrocarbons (TPHs) were determined at harvest 120 days after planting. A significant difference was observed in the bacterial counts (total and oil-degrading bacteria) between the planted soils and the control. In contaminated soils, a higher microbial activity was observed in the rhizosphere of the sorghum soil than in that of barley. TPHs concentration decreased by 52%‒64% after 120 days in contaminated soil in which sorghum and barley had been cultivated. This represented an improvement of 30% compared to the contaminated soil without plants. Based on the results obtained, sorghum and barley may be recommended for the removal of petro-contaminants in areas close to Isfahan Oil Refinery. Nevertheless, caution must be taken as such cultivated lands may need to be protected against grazing animals.

Gastrointestinal motility disorders are considered one of the most common digestive problems in the intensive care units that mainly appear as decreased gastrointestinal motility and constipation. The current study is to evaluate theincidence of constipation in the intensive care unit and effect of medications to treat it. 31 patients were studied. Inclusion criteria were age≥ 18 years، hospitalization in the intensive care unit for more than three days، receiving enteral nutrition and non-malignant gastro intestinal or stomach surgery. Evaluation criteria forconstipation was lack of gastrointestinal excretion for three consecutive days. Constipation occurred in 61. 3% (n=19) of the patients. There was no difference between constipated and not constipated in terms of sex، age، Acute Physiology and Chronic Health Evaluation II، mechanical ventilation، sedation and opiate use. Incidence of constipation with increased length of stay in the intensive care unit were significantlycorrelated (11. 5±5 days vs. 6. 5±5 days). There was no difference between patient using laxative and other patients in the incidence of constipation. Despite medical treatment، constipation in ICU، had a high incidence that increased duration of hospitalization. Several factors influencing the incidence of constipation and lack ofatreatment protocol from doctors and nurses is the most important reason for the high prevalence of constipation.

Health sector and its infrastructure needs in both software and hardware sector has always been emphasized. Among importance of the medical equipment and items in the health system of the country is not covered on any one. Organizations and companies active in this sector should be able to take correct decisions with regard to information in the volatile business environment today on time. Thus, estimating demand in future periods seems vital. There are various methods and tools for forecasting demand that each have advantages and disadvantage its own special. In this paper, using a multilayer neural network with two hidden layers that has been learned with genetic algorithm as the learning algorithm, the comparative system with Common method used in the prediction (Box - Jenkins Method) with model ARIMA (2,1,1) has been presented for the forecasting demand CT-Scan set, that According to the measure of the accuracy of models, the mean squared error (MSE), the neural network model shown of the more effectiveness and efficiency as compared to ARIMA method according to the data and information in forecasting demand CT-Scan set.