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In this research, biodiesel was initially produced from waste vegetable oil by transesterification reaction. The main properties of this fuel were compared with the ASTM D-6751 standard.then, performance of MF-399 tractor engine was tested and evaluated by using 5 to 25 percent biodiesel and diesel blends. Test results showed that, the power and torque of MF-399 tractor engine were increased, using biodiesel and diesel blends. This is because of good combustion of biodiesel due to high oxygen content of this fuel. There was also a slight increase in the fuel consumption and specific fuel consumption of biodiesel and diesel blends due to low calorific value of biodiesel. Results show that the B5D95 blend has the best performance and the lowest increase in specific fuel consumption among the other blends. The fuel consumption and specific fuel consumption of B25D75 was lower than the B20D80 blend. Therefore, if the goal is using high amount of biodiesel, B25D75 blend is recommended for use in MF-399 tractor engine.

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Biofuels are the main substitute to fossil fuels. These fuels are less polluting in compari-son to fossil fuels and can be produced from agricultural material residues for use in die-sel engines. In this research work bioethanol was produced from potato waste. It was de-hydrated in a vapor phase using 3A zeolite and was used in combination with sunflower methyl ester oil and diesel fuel blending which was evaluated thereafter. The sunflower methyl ester was also produced using a transesterification method. Considering the labo-ratory conditions and fuel stability limits to be used, the suitable blending proportion of bioethanol and diesel fuel was determined to be 12 to 88 and then, for maintaining fuel stability at temperatures lower than 15oC, the sunflower methyl ester was added to the mixture. The pour point of the fuel and different fuel blends, the viscosity, cetane number, flash point, amount of fuel ash, sulfur content and copper corrosion were determined in the laboratory. Experiments show that ethanol plays an important role on the flash point of the blends. With the addition of 3% bioethanol to diesel and sunflower methyl ester, the flash point was reduced to 16oC. The viscosity of the blends was reduced with the in-crease in the amount of ethanol. The sulfur content of bioethanol and sunflower methyl ester is very low compared with that of diesel fuel. The sulfur content of diesel is 500 ppm whereas that for ethanol and sunflower methyl ester is 0 and 15 ppm, respectively. The lower amount of sulfur content facilitates the use of fuel blends in diesel engines. For the ethanol and sunflower methyl ester combination, this amount is less than 20 ppm.

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Sour orange juice has found application in various foods as alternative of lime juice, due to its desirable taste. Different thermal processes could be performed to improve safety and shelf life of this product. In this study, the sour orange juice was processed at four microwave power levels (170, 340, 510 & 680 W) in a various periods of time to reach the product temperature to 72^˚C. The aim of this study was to investigate the effect of heating processes on the some physicochemical properties of sour orange juice during come up time. Based on the results, different power levels of microwave have no significant effects on viscosity. The thermal destruction of Ascorbic acid and Pectin methyl esterase were found to follow first order kinetics. Destruction rate of these two compounds were also increased by increasing microwave power. Because of the effect of microwave power on chemicals especially ascorbic acid, the colorimetric parameters of the product changed as a result of changing in microwave power. By considering the high regression (R²> 0.97) between two measuring methods (spectroscopy and image processing), the image processing method is suggested as browning index during thermal processing.

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The content of phytochemicals of medicinal plants including total phenols, flavonoids, fatty acid compounds, etc. are mainly affected by drought stress.  In this study, the effects of different levels of water stress (Full irrigation at field capacity, irrigation at 70% of field capacity and irrigation at 40% of field capacity) on the phytochemicals of the medicinal plant of Milk thistle were evaluated. Soil moisture was measured by weight method and drought stress was applied to plants during the flowering stage for 8 days. Then, the seeds were oiled by Soxhlet and methanol extracted. Next, the phytochemicals of the extract were analyzed using GC-MS. GC-MS peak analysis indicated that 20 compounds were present in methanolic extract of Milk thistle. Oleic acid was the most abundant compound in irrigation treatments of Field Capacity (F.C) (75.8%) and 40%F.C. (73.7%), while methyl linoleate (22.5%) was highest in 70%F.C. Except of oleic acid, which had the highest amount in F.C and 40%F.C, the other compounds had the highest amount in 70%F.C compared to the other two treatments. According to the results, mild stress increased most of the plant's phytochemical compounds, possibly due to the osmotic regulation of the plant in dehydration. However, under extreme stress, these compounds were reduced, and these metabolites may have been used to provide energy for plant growth and survival. According to the results of this study, since the seeds of this plant have important phytochemical compounds such as fatty acids, phytosterols, methyl esters, flavonoids, etc. Therefore, the above compounds can be used in the food, pharmaceutical, health and other industries after extraction and purification.

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Fruits of two apricot (Prunus armeniaca L.) cultivars ‘Bagheri’ and ‘Asgarabadi’ were treated with 1 or 3% of Calcium Chloride (CaCl₂) or Calcium propionate (Ca pro) and stored at 1°C, 90% RH for 21 days (d). Fruits were sampled weekly and stored for 2 days at 20°C for shelf life study. Chilling Injury (CI), firmness, color, Titratable Acidity (TA), Soluble Solid Content (SSC), fruit calcium concentrations, Pectin MethylEsterase (PME) enzyme activity and pectin content were monitored during the storage period. CI was first detected in the control fruit after 7 days, and incidence and severity of CI in control fruit was higher than in calcium treated fruit after 14 days. Calcium treatments increased fruit calcium concentrations and delayed ethylene production, as well as softening and color changes. PME activity and water-insoluble pectin decreased while water-soluble pectin increased during fruit storage. Higher calcium concentrations may help to maintain fruit quality by alleviating CI incidence and inhibiting ripening in fruit stored at low temperature.