فهرست مطالب حسن پوروثوقی گرگری

The influences of different diesel/biodiesel blends and EGR rate on brake specific fuel consumption (BSFC), exhaust gas temperature, NO, HC, CO emissions, are studied and demonstrated. In this paper a four stroke direct injection, water cooled, diesel engine was used. Biodiesel either in neat form or as a blend with diesel fuel is extensively investigated to solve the twin problem of reduction of fossil fuels and ecological degradation. Exhaust gas recirculation (EGR) is an impressive technique for decreasing NO emissions. When EGR is utilized in engine, NO emission is decreased. If the engine was fueled with biodiesel-diesel blends, the BSFC would increase due to the lower brake power produced and It was found that BSFC increased with increase in EGR rates. Engine power and torque decreases through the use of biodiesel fuel blends. The results showed that B0 stands on the top level of power and B50 is at the lowest level. Reduction in exhaust gas temperature was observed but emissions of HC and CO were found to be increased with usage of EGR.

Vehicle Emission is one of the main causes of environmental damage. Vehicle engines produce carbon dioxide (CO2), hydrocarbon (HC), Nitrogen oxides (NOx) and many other harmful substances. An investigation was conducted using a compression-ignition engine fuelled with different ratios of blends of diesel and biodiesel at different EGR rates. The effects of different ratios of fuel blends and EGR rate on the emission characteristics (unburned hydrocarbon (HC), nitric oxide (NO), carbon dioxide (CO2) and oxygen (O2) were examined. The air-fuel equivalence ratio (λ), oil temperature and intake gas temperature were also analyzed. Results show that the different ratios of blends of diesel and biodiesel decrease HC emissions compared to those of the diesel fuel. The addition of biodiesel can increase NO, CO2 and O2 emissions compared with that of the diesel. EGR can reduce NO emissions in a compression-ignition engine fueled with diesel and biodiesel blends. The results also indicate that fuel consumption and air-fuel equivalence ratio were decreased by 19.2% and 72.9%, respectively, for 20% biodiesel blend with 20% EGR compared to diesel fuel without EGR. Intake gas temperature and oil temperature were also observed to increase by 87.5% and 6.2%, respectively, for 20% biodiesel blend with 20% EGR compared to diesel fuel without EGR.

The necessity to use pesticides in agriculture, provides environmental pollution at the same time, and significant part of the agri-economy is allocated to this reseon. Therefore, it is important issues to use of pesticides, with the highest degree of effectiveness and minimal loss. In this study, electrostatic spraying and its functional factors were evaluated. The applied experimental design was completely randomized factorial test with three replications. Investigated Factors include the distance electrostatic head to the target (three levels), the engine rotational speed sprayer (at three levels) and the discharge of soluble from the nozzle outlet (at three levels). As well as to determine the amount of drift for charged toxin particles, factors factorial experiment with the electric charging factor (two levels), the wind speed (two levels) and the distance from the head (at three levels) was performed. Assessment of pesticides particle images effects on water sensitive paper, was conducted using image processing toolbox of MATLAB and coding an image processing algorithm. The results showed that significance of examined factors were different depend on the upper and rear surfaces of leaves, in some cases. Also in surface coverage percent factor, electric charging of particles statistically significant with a probability of 99%.