نشریه تحقیقات سامانه ها و مکانیزاسیون کشاورزی
پیاپی 68 (بهار و تابستان 1396)

Composting livestock manure and municipal solid waste is an appropriate method for waste management in order to stabilize organic wastes. The low specific mass of compost causes problems in transportion and storage activities and increases the costs. In this study some parameters affecting the pellets production was investigated. Parameters considered were: particle size (1 and 2 millimeter), pellet moisture content (25, 35 and 45 percent) and kneading length (1, 2 and 3 meter). Results showed that the specific density of pellets produced under both levels of particle size, increased with increasing the Length of kneading at all levels. Interaction effect of moisture content and kneading length on the rate of fractured pellets showed that, the maximum amount of force was (556.32N) which belonged to treatment with (moisture content of 35% and length of kneading of 3 m). Also the interaction effect of particle density and length of kneading showed that maximum toughness value was (1.03 MJ/m3) which belonged to particle density of 1mm and kneading length 3 m.

Machine vision technology can be used to detect the location of weeds around the main crop in a field as the machine moves, in order to decrease the losses of using herbicides. The purpose of this research is to determine the accuracy of image processing method in discriminating weeds from potato crop according to color features. Therefore, by performing a research which conducted in university of Mohaghegh Ardabili research field, three factors including: environmental light condition, type of weed (Shalambig, Pichack and Wheat), and level of crop growth, were investigated on discrimination accuracy. The results of this research were showed that there are no significant differences between two types of environmental light conditions. However, the main and interactive effects of two factors of type of weeds and level of crop growth was significant on discriminating system performance. According to this study, the first stage of crop growth is the best time for the visual tests (middle of the June) and among the three types of popular weed in the region, it is possible to discriminate the wheat from potato leaves with a reasonable accuracy according to RGB color model. By this method, it is possible to determine the location of weeds around the main crop by maximum accuracy of 95% dependent to different condition of treatments.

In this research suitability of dimension and size, location of some control equipment’s and driver surroundings with dimension, sizes and abilities of tractor drivers in Fars province was evaluated. Anthropometric data was essential requirement for adjustment of machine equipments with potentiality and competence of human. In this project the first necessary anthropometric data, for about 250 tractor drivers that were in age range of 20–60 year was measured randomly. The next some of prevalent tractors specifications in Fars province with anthropometric data of fifth and ninety and fifth percentiles of drivers was compared and evaluated. The results showed that stair space of evaluated tractors from the ground was more than optimum range. Chair depth of New Holland and Valtra tractors for fifth percentile drivers was great and for elimination of this difficulty proper seat back with adjustable thickness was recommended. The surveys showed that chair depth of model 285 and 399 of massey furgousen tractors was shorter than thigh length of ninety and fifth percentile drivers, which caused the driver’s discomfort. In massey furgousen tractor model 285 and Valtra tractors distance of steering wheel from seat reference point was more than hand length of fifth percentile drivers. Therefore the length of drivers hand was considered to be short for proper grip on steering wheel. The surveys showed that the drivers of massey furgousen tractors (Model 399) faced difficulty in for accessing the gear lever.

A three-phase Delphi study was conducted to identify factors affecting efficiency of tea factories in Gilan Province of, Iran. In this context, 20 experts from the Iranian Tea Organization (ITO) and agricultural offices of Roudsar, Amlash, Langaroud, Lahijan, and Siahkal of Gilan Province were selected as the members of the research panel. According to the consensus of Gilan’s tea processing experts provision of suitable tea leaves, benefitting from skilled tea and acquisition of well-established and organized factorywill result in 97.17%, 92.44% and 90.37% efficacy in management of tea processing factories respectively.. Further paying attention to cultural practices, particularly pruning and providing adequate fertilization as well as implementation of mechanized irrigation should be regarded and practiced by tea growers as well as Iranian Tea Organization (ITO). Moreover, training and educating the tea processors in tea factories through conduction of educational courses by using experienced educators as well as coordination of supply of tea leaves by producers according to the processing capacity of factories in each region are considered as important factors and are recommended.

Parboiling is a hydrothermal treatment and it consists of 3 steps: soaking, steaming and drying of paddy. In this research RSM and central composite design was used for optimization of parboiling indicators (soaking temperature and steaming time). After soaking temperature of (55, 60, 65, 70 and 75 oC) and steaming time of (2, 4, 6, 8 and 10 min), the samples were dried for three days in the shade to a final moisture content of 11±1% (w.b.). Using multiple regression analysis a quadratic polynomial equation was developed for each response. Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The results showed that the effects of soaking temperature and steaming time were found to be significant (p

Traction efficiency and fuel consumption hgave close affinity and are considered to be important unit operations, especially during primary tillage operations. Therefore, analyzing factors that affect the amount of Traction efficiency and fuel consumption is considered important. Amongst these factors, forward speed of tractor and tillage depth are of prime importance. Experiments were conducted for comparison of draft force and fuel consumption using, three types of cultivator blades (flat Duckfoot, Duckfoot with curve shank and Chisel plow), under sandy loam soil condition by using a factorial experiment based on randomized complete block design (RCBD). The effect of forward speed (3, 6.5 and 9 km/h) and tillage depth (10 and 20 cm) was the experimental conditions. Within each experimental plot, draft force of cultivators, fuel consumption, soil cone index, soil dispersion and percent of soil moisture content were measured.Analysis of variance showed that the effects of the blade type, forward speed and depth on the draft force and fuel consumption was significant at 1%. Comparing the draft force and fuel consumption of blades in different forward speeds and also considering the relatively light texture of the soil, it was found that duckfoot blade with curve shank with forward speed of 3 km/h was more appropriate.

One of the main problems of crops dryers is their high cost, high energy consumption, and the associated higher cost of operation. The solution proposed for this problem is use of the free and clean solar energy. In this study, a solar dryer was developed, which consisted of a solar collector that innovatively is made of discarded waste materials such as cold drinks metal cans. Also Phase change materials (PCM), was included in the dryer chamber for energy storage, and was tested under laboratory conditions, and air flow rate, temperatureand radiation intensity were measured. According to the results, the temperature of the absorber plate of the innovatively solar collector increased up to 111 ºC and the temperature of the exhust air had a difference of 50 to 60 ºC compaed to the ambient temperature. Highest tempratur increase was obtained with air velocity of 0.5 m/s at 2- 3 PM in test days. The phase change temperature of the materials occurred at 51 to 53 ºC. When the chamber temperature exceeded 53 ºC, the material’s phase changed and the stored heat was directed to dryer in order to compensate for the tempratuer drop in the plenum. . As result, the temperature loss of the drying chamber occurred less severly under the phase change material conditions, because it slightly prevented temperature loss. Finally, mintdrying test was carried out. The mint with an initial miostuer content of 86 percent, lost 86g of its moisture and reached final moister content of 12 percent during the product test in 273 minutes, under mean chamber temperature of 44.3 ºC and air velocity of 0.5 m/s.

The aim of this study was to design, Constructand evaluate an electronic system for control of the forward speed control in 7000 series sugarcane harvesters. The conventional method of control for the forward speed of sugarcane harvester in 7000 series is mechanical. The new electronic control system was developed to replace the traditional mechanical control system. MotorStepper, drivers, micro-controller, joystick and potentiometer were used to program microcontrollers as well as C programming in code-vision. The new control system was evaluated during two series of tests. To determine the strength of the maneuverability of the harvesting machine, the first test was conducted using a factorial experiment based on completely randomized design. The maneuverability was compared for mechanical and electronic control systems under different engine rpm. The location error at stoppage time in respect to the baseline was measured as basis for maneuverability. In the second test the response time was compared with a completely randomized design in two systems. The statistical analysis showed a statistically significant difference between the control systems in 1% probability level. The maneuverability of harvester equipped with electronic control system increased significantly and it was not affected by the changes in engine rpm (forward speed). In the second test the statistical analysis showed a statistically significant difference between the control systems in 5% probability level. Electronic forward speed control system resulted in reaction speed, and device maneuverability, ease of maintenance and use, a reduction in mechanical parts usage and finally the proper functioning of the system.

In order to achieve a conservation agriculture, a new strip tillage implement was designed that could be pulled with a drill by tree point hitch attachment in order to make possible tillage and planting practices simultaneously. The developed drilling machine was then used and compared with other tillage methods. An experiment was designed using Randomized Complete Block (RCB) with three replications. Main plots were: The four tillage and planting methods namely: moldboard plow 2 passes of disc leveler drill (T1), 2 passes of disc leveler drill (T2), chisel packer drill (T3) and strip-till-drill (T4 or STD), and the subplots namely: seed density of 160 (S1), 200 (S2) and 240 (S3) kg.ha-1 were the experimental conditions.. Evaluated indices were fuel consumption rate, operation time, field capacity and residue pulverization rate. The results showed that T4 treatment had the lowest fuel consumption and time with 8.6 lit.ha-1 and 1.62 h.ha-1 rates, respectively. T1 and T4 treatments with 0.2 and 0.62 ha.h-1 had the highest and the least rates of field capacity. Residue pulverization was 46.47% in T4 treatment and was not significantly difference with T2. Crop yield in T4 treatment was 11% higher than average of other treatments. Finally it was found that tractors with medium power such as MF285 (with 53 kW engine power) could pull this implement.

The present paper investigated the feasibility of using texture-based features of laser backscattering images in monitoring and modeling of apple slices shrinkage during hot air drying. The backscattering imaging was performed at three wavelengths (650, 780 and 880 nm) in the visible and near-infrared regions. The acquired images were subjected to four texture analysis methods including first-order statistics of image histogram, co-occurrence matrix, gray level run-length matrix and wavelet transform. Stepwise multiple linear regressions was used to develop models and determine the most effective features by using individual types of feature sets and their combinations as inputs of calibration models. The results showed the capability of the texture features extracted from the laser backscattering images in the near-infrared wavelength range for prediction of apple slices shrinkage; by using homogeneity feature of co-occurrence matrix-90˚ at 880 nm (with Rp2=0.95, RMSEp=5.15) and fusion of the four feature sets extracted from different texture analysis methods at 780nm (with Rp2=0.94, RMSEp=5.61), could make models with high accuracy. This study showed that Laser backscattering imaging technique can be used as a non-destructive, rapid and low-cost method for prediction of the shrinkage in the process of hot air drying of apple slices.