Journal of Researches in Mechanics of Agricultural Machinery

Abstract The present research was conducted to evaluate the energy-economic and environmental indexes in two methods of rainfed fodder production (vetch pure cultivation and vetch-barley mixed cultivation) on a farmer's farm in Khorramabad county in the 2021-2022 cropping year. Planting vetch in a pure form with a density of 250 seeds/m2 and vetch-barley mixed cultivation with a ratio of vetch:3 and barley:1 was considered. According to the results, the average yield of wet and dry fodder in vetch pure cultivation was 8482 and 2800 kg/ha, respectively, and for vetch-barley mixed cultivation, it was 17950 and 6000 kg/ha. Comparison of the average yield using Student's t-test showed that the difference between wet and dry fodder yield mixed cultivation of vetch-barley with pure vetch cultivation was statistically significant. The total average of input and output energies in pure vetch cultivation and vetch-barley mixed cultivation (8675.25 and 48244 MJ/ha) and (8795.08 and 98880 MJ/ha) respectively, and the values of energy ratio and energy productivity in two methods of fodder production were calculated as (5.56 and 0.322 kg/MJ) and (11.12 and 0.682 kg/MJ), respectively. The global warming potential was obtained in the vetch pure cultivation and the vetch-barley mixed cultivation, respectively, 566.5 and 578.9 (kg eq. CO2)/ha. Also, the average net return and the benefit-cost ratio of rainfed fodder production in vetch pure cultivation and vetch-barley mixed cultivation were estimated as (40793000 Rial/ha and 1.51) and (173473000 Rial/ha and 3.05), respectively. According to the results of the evaluation of energy-economic and environmental indexes in two methods of rainfed fodder production, vetch-barley mixed cultivation is recommended as the superior treatment in the region.

Abstract Dryers play a very important role in the processing of food, chemical and pharmaceutical products. The drying performance depends on various factors such as the type of dryer, the temperature and speed of the air entering the dryer, the size and amount of input, the remaining time of the material in the chamber. For this reason, it is necessary to carry out specific studies in the field of drying products. On the other hand, designing, manufacturing and equipping dryers with sensors to measure various parameters is a costly process, and numerical and simulation methods have been used in recent researches to analyze dryers. Therefore, in this article, the parameters affecting the drying process in a cross-flow fluidized bed dryer with a tray were investigated by CFD method. For this purpose, the effect of material mass flow in 3 levels is 2.76, 5.76 and 1.8 degrees per hour, the speed of incoming hot air in 4 levels is 2.5, 3, 4 and 5 meters per second and the temperature of hot air in 4 The levels of 50, 60, 70 and 80°C on the speed and pressure inside the chamber were evaluated by ANSYS fluent 18 software. The results showed that an increase in temperature led to an increase in air pressure and speed inside the chamber and in the bed. Increasing the flow led to a decrease in pressure and speed.

Abstract The interaction of wheel and soil has received much attention from the researchers of this department due to its effects on energy consumption and soil characteristics, especially in the field of agriculture. In this research, the amount of wheel indentation in the soil and the traction force required by the moving wheel, which are the determining parameters in the wheel-soil interaction, were measured using a wheel tester in the laboratory soil storage environment. Tests in 2 different levels of speed (0.386 and 0.879 km/hour), 3 different levels of tire pressure (18, 25 and 32 pounds per square inch) and 3 different levels of load Vertical loading on wheels (150, 300 and 450 kg) was carried out in the form of a randomized complete block design in 3 repetitions and a total of 54 surveys. Then, using adaptive neuro-fuzzy inference system (Anfis) and multivariable regression model, the amount of indentation and required tensile force were predicted. In order to evaluate these models, correlation coefficient (R2) and mean square error (MSE) were used. The results showed that tire air pressure, vertical force and moving speed of the moving wheel have a significant effect on the depth of the wheel indentation in the soil (P<0.01). They do not have correlation coefficient in predicting the amount of indentation and tensile force by Enfis models was equal to 0.9901 and 0.6911, respectively, which was much higher than the correlation coefficient in regression models, which was equal to 0.8743 and 0.4061, respectively. Also, the mean square error in Enfis models regarding the indentation and traction force of the wheel is 0.0231 and 0.0101, respectively, which is much lower than the mean square error in the regression models, which is equivalent to 0.864 and 0.918, respectively. Be Therefore, Anfis models have higher accuracy and less error than regression models.

Abstract This study investigates the application of random forest algorithm in relation to spectroscopic techniques, especially Vis-NIR (Vis-NIR) spectroscopy, to predict key quality characteristics of cherries. The aim of this article is to provide a reliable and efficient method for non-destructive evaluation of sugar content, acidity and hardness which are important factors determining cherry quality and consumer acceptance. In this study, 200 random samples of cherry products were prepared. Spectral data were obtained. The spectral data obtained from Vis-NIR spectroscopy were evaluated by the Relief method, and five effective wavelengths were selected separately for each of the values of the dependent variables of sugar, acidity, and hardness values. The selected effective wavelengths were then used as input features for a random forest model, which was trained on a dataset containing samples with known sugar content, acidity levels, and hardness measurements. The performance of the model was evaluated in terms of prediction accuracy and robustness through cross-validation and independent testing using root mean square error (RMSE) and correlation coefficient (CC). The results showed that the effectiveness of the random forest algorithm in accurately predicting the sugar content, acidity and hardness of cherries based on spectral information. The proposed approach provides a rapid, non-destructive and cost-effective solution for quality assessment in the cherry industry and enables producers and stakeholders to make informed decisions about harvesting, sorting and post-harvest processes.

Abstract The correct method of spraying herbicides is an important factor affecting weed control. In this regard, three types of herbicide sprayers including tractor mounted boom sprayer, knapsack atomizer and knapsack boom micronair were investigated to control weeds in the corn fields of Safiabad Agricultural Research Center, in Dezful, Iran. In order to compare the performance of these three sprayers, a randomized complete block design with five treatments and three replications was implemented. The treatments of this experiment included spraying by a mounted tractor boom sprayer, knapsack atomizer, knapsack boom micronair, and weeding by a human (first control), as well as no weeding and spraying (second control). After identifying the types of weeds in the field, nicosulfuron herbicide was applied. The results showed that the lowest means of weeds dry weight including Cleome viscosa, Corchorus olitorius, Cyperus rotundus, Physalis alkekengi and Convolvulus arvensis belonged to the micronair sprayer treatment with the values of 2.53, 2.92, 2.94, 1.43 and 1.92 g.m-2 respectively. The study of corn yield and yield components showed that among the spraying treatments, the highest mean of biological yield, number of corn plants per unit area, corn ear weight per unit area, number of seeds in a row of an ear, wood weight of an ear, thousand-seed weight, corn plant height, a corn ear weight and seed weight of an ear of corn belonged to micronair sprayer treatment with the values of 30 t.ha-1, 74000 plants per hectare, 12.93 t.ha-1, 36.3 seeds per row, 46 g, 415 g, 299 cm, 260 g and 216 g respectively.

Abstract In developing countries, traditional transplanting is one of the conventional methods at the farm level. In this method, the environmental pollution from plastic trays destroys the structure and soil texture. For this reason, nowadays, they use an alternative method, degradable pots. This research investigated the characteristics of two types of renewable pots using a pressure test device with three humidity levels in three repetitions. The general goal is to introduce the best pot for planting seedlings in a smart device to develop technical knowledge and increase planting productivity with the least waste in Iranian farms. The results showed that the type of pot, for parameters density, ultimate stress, displacement in ultimate stress, yield stress, and displacement in yield stress at the level of 5% and water absorption time, for parameters density, humidity, ultimate stress, displacement in ultimate stress, yield stress, displacement in yield stress and pot thickness is significant at 1% level. Also, the simulation test result of incomplete conical cylinder and square pyramid renewable pot using Ansys software with laboratory data showed a coefficient of determination of 88 and 91%, respectively. According to the present research, the best option for planting in the smart planter is to sample the incomplete conical cylinder pot with the initial moisture content and the duration of 30 minutes of water absorption.

Abstract Urban air pollution is primarily attributed to using gasoline-fueled cars with internal combustion engines, leading to a depletion of fossil fuel reserves, increased pollution from combustion, and respiratory illnesses. One approach to mitigate combustion-related pollutants is the incorporation of biofuel-based additives. Glycerin, a byproduct of biodiesel production, plays a crucial role in synthesizing these additives. This study focuses on converting glycerin derived from sunflower oil into Solketal-acetin, a novel biofuel blend with gasoline. This unique fuel blend exhibited favorable characteristics at specific composition ratios. The performance of the Solketal-acetin additive blend with gasoline was evaluated in a 150 cc motorcycle under various loads (1/2, 6/2, 11/2 Nm) and speeds (570, 850, 1044, 1269, 1427rpm) to assess fuel exergy efficiency and net-work exergy input. At a load of 11/2 Nm and a speed of 1427-1269 rpm, engine shutdown occurred across all fuel injections due to excessive load and inadequate thermal capacity of the fuel. The findings indicated that adding triple compounds to gasoline fuel enhanced the braking power exergy due to the high density of these compounds.

Abstract Today, the consumption of fossil fuels is known to be unsustainable due to the rapid destruction of valuable resources and the production of environmental pollutants, and it has prompted researchers to find a good alternative to this by using renewable energies and expanding them with the help of appropriate processes. Biodiesel is one of the best-suggested sources. Oscillatory baffled reactors with high stirring intensity in less time and more volume has attracted the attention of many researchers in recent years. This study aims to evaluate the two-chamber oscillatory baffled reactor in the continuous production of biodiesel. The ultrasonic system has been used as a suitable pre-mixer, and waste oil has been used to reduce production costs. The molar ratio of methanol to oil (1:6, 1:9, and 1:12), time (1, 3, and 5 minutes), oscillation frequency (2.4, 3.7, and 4.9 Hz), and temperature (40, 50 and 60 °C) are the four factors that were investigated in this research. The physical and chemical characteristics of the biodiesel produced follow ASTM standard D6751. The response surface method was used to optimize the content of methyl ester produced, and The results indicated that the highest performance of biodiesel is 95.28%, along with the lowest energy consumption of 58.80 in the molar ratio of 8.01, time of 2.55 minutes, oscillation frequency of 3.64 Hz and temperature 49.05 degrees Celsius. The production of biodiesel with a high conversion percentage and in a larger volume by the fluctuating flow reactor, which was associated with a shorter reaction time, was another result of this research.