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One of the most important factors involved with soil-engaging agricultural field operations is soil adhesion. Reducing soil adhesion has significant effects on the operation and energy consumption of agricultural machines. In this study, a laboratory method has been carried out to study the effects of ultrasonic waves on soil adhesion. Normal adhesion tests were performed on two types of soil using three plates with different contact areas. The plates consisted of an iron ring as the main body covered by a stainless steel sheet on the top and an aluminum sheet at the bottom. The internal space of the plates was filled with a fluid that was capable of transmitting the waves produced by piezoelectric crystals attached under the top sheet. When ultrasonic waves reached the metal surface which was in contact with the soil, soil adhesion force was measured while the plate was separating from the soil. Experimental results revealed that ultrasonic waves have a significant effect on soil adhesion in different moisture contents. The results of the analysis of variance (ANOVA) indicated that all the test parameters had significant effects on reducing the soil adhesion to the metal plates. However, multiple effects of frequency and other parameters on the soil adhesion were not significant. An increase in ultrasonic frequency from 0 to 1800 kHz had a significant effect on soil adhesion to metal plates at a 5% level. Results showed that the most effective application time that causes more reduction in soil adhesion is 60 s. The soil adhesion decreases with increasing frequency Ultrasonic waves significantly affect soil adhesion in different moisture contents; The effects of ultrasonic waves on soil adhesion were similar in different soil types, moisture contents, and test plate sizes. [ABSTRACT FROM AUTHOR]

The information of the impact cutting behavior of plants stalk, play an important role in the design and fabrication of plants cutting equipment. It is difficult to investigate a theoretical method to define cutting properties of plants stalks because the cutting process is complex. Thus, it is necessary to set up an experimental approach to determine cutting parameters for a single stalk. To measure the shear force, shear energy and shear strength of plant stalk, a special impact cutting tester was fabricated. The apparatus included four strain gages and a digital indicator to show the real-time cutting force and requirement cutting energy of plant stalk. To test the apparatus, a series of laboratory tests were conducted to measure the shear force, shear consumption energy and shear strength of stem internodes of two plants stalk like boxwood or box with a scientific name of Buxus (Buxus Sp) and privet with a scientific name of Ligustrum Ovalifolium (Oleaceae Sp) under impact cutting at four loading rates (1, 2, 3 and 4 m/s) and three internodes of stalk (fifth, tenth and fifteenth). At boxwood cutting analysis: the minimum and maximum values of shear consumption energy were obtained as 3.19 J at fifth internode and loading rate: 4 m/s and 19.6 J at fifteenth internode and loading rate: 1 m/s, respectively. The minimum and maximum values of shear strength were obtained as 0.06 MPa at fifth internode and loading rate: 4 m/s and 1.55 MPa at fifteenth internode and loading rate: 1 m/s, respectively. At privet cutting analysis: the minimum and maximum values of shear consumption energy were obtained as 3.95 J at fifth internode and loading rate: 4 m/s and 28.56 J at fifteenth internode and loading rate: 1 m/s, respectively. The minimum and maximum values of shear strength were obtained as 0.2 MPa at fifth internode and loading rate: 4 m/s and 2.50 MPa at fifteenth internode and loading rate: 1 m/s, respectively. [ABSTRACT FROM AUTHOR]

Threshing wheat (Triticum aestivum LO at high speeds is the main reason behind abnormal seedlings and vigor reduction of the seeds. This problem is expected to be severe in headstripper combines with successive impact Ioaclings of stripping and threshing units. The airo of this study was to simulate the effects of impact velocities (IV), number of impact loadings (NL), and seed moisture content (MC) on percentage of physical damage (PPD) and percentage of Ioss in germination (PLG) to wheat seeds. Modeling the correlation between dependent ancI independent variables was performed using mathematical and artificial neural networks (ANN). The result showed that all the three independent variables significantly influenced PPD and PLG (P = 0.01). Increasing the IV from 5 to 30 m [s.sup.-1] caused an increase in PPD and PLG from 0.17 to 35.8% and from 0.37 to 19.9%, respectively. It was found that the seeds with higher MC could better withstand physical and physiological damage than those with Iower MC. With an increase in NL from 1 to 3 times, the mean values of PPD and PLG were increased by 2.9 and 2.6 times, respectively. An ANN model with two hidden layers, trained with a back-propagation algorithm, successfully learned the relationship between the input and output variables. In comparison with regression models, ANN performecI better when predicting PPD and PLG to wheat seeds.

Several methods have been developed to measure the friction coefficient of grains and seeds as well as their angle of repose, independently. However, it seems that one single method capable of simultaneous measurement of these two important parameters of grain products is of importance. In this study, simultaneous measurement of brown rice grain friction coefficient and angle of repose is performed by using rotating cylinders method. The effects of rotational speed, cylinder diameter and filling degree on rice grains, also lower and higher angle of repose along with their friction properties were considered. Results showed that proper speed for reaching slumping and rolling motions depends on cylinder diameter and filling degree varying from 0.5 to 9.7 rpm and 2 to 34.6 rpm, respectively. An insignificant difference in the range of 1° to 4° was observed between lower and upper angles of repose which indicates the reliability of the proposed method to determine the dynamic angle of repose. Results also revealed that rotational speed of cylinders did not significantly affect the lower and upper angles of repose; however, they were not affected by filling degree. Finally, the friction coefficient of rice grains was affected by cylinder diameter and filling degree. The findings of this study may be applied in the design and mathematical modeling of grains' motions in rotary dryers, mixers, and silos. [ABSTRACT FROM AUTHOR]

Some of agricultural operations such as privet stem pruning are slow, repetitive and occasionally dangerous for operators. Almost operators of privet trimmers are exposed to the unpleasant and dangerous arm and body vibrations and sound of pruning machines. The knowing of the shearing behaviors of privet stem have an important role in the design and fabricate of suitable pruning machine. So a series of experimental tests were performed to measure the shear force, shear consumption energy and shear strength of stem internodes of privet stalk under quasi-static and impact cutting at different loading rate, different internode position and moisture level 58% wet base. In the quasi-static cutting test, the stalk specimens were cut in the quasi-static process at four loading rates: 5, 10, 15 and 20 mm min-1 and three internode positions: fifth, tenth and fifteenth. In impact cutting test, the stalk specimens were served in impact process at four loading rates: 1, 2, 3 and 4 m s-1 and three internode positions: fifth, tenth and fifteenth. In quasi-static cutting, the variance analysis of the data indicated that the loading rate created significant effect on shear strength and shear consumption energy in probability level of 5%. Also the internode position and the interaction effect of loading rate and internode position, created significant effects on shear strength and shear consumption energy in probability level of 1%. Based on the statistical analysis, the average values of shear consumption energy and shear strength were obtained as 556.70 J from 95.35 to 1567.95 J and 29.12 MPa from 19.63 to 37.04 MPa respectively. In impact cutting, the variance analysis of the data results showed that the effects of loading rate, internode position and interaction effect of loading rate on internode position, created significant effect on shear consumption energy and shear strength in probability level of 1%. The data statistical analysis showed the average values of shear consumption energy and shear strength were obtained as 17.16 J from 3.19 to 28.60 J and 1.01 MPa from 0.21 to 2.53 MPa respectively. [ABSTRACT FROM AUTHOR]

The information of the shearing properties of buxus stalk plays an important role in the design and fabrication of buxus pruning machine. A series of laboratory tests were conducted to measure the shear force, shear consumption energy and shear strength of stem internodes of buxus stalk under impact cutting at four loading rates (1, 2, 3 and 4 m s-1), three internodes (fifth, tenth and fifteenth), and moisture content level 72% w.b. In this test, the stalk specimens were served in impact cutting process by using a special cutting test apparatus that was designed, fabricated, and calibrated. To define the impact cutting force of buxus stem, the apparatus was attached with beam type load cell and shear blade. The variance analysis of the data results showed that the effect of loading rate and internode position on shear consumption energy and shear strength were significant (P<0.01). Also, the interaction of loading rate and internode position effect on mentioned parameters were significant (P<0.01). The results showed shear strength and shear consumption energy decreased with an increase in loading rate and upward from fifteenth to fifth internode position. The minimum and maximum values of shear consumption energy were obtained as 3.19 J at fifth internode and loading rate: 4 m s-1 and 19.6 J at fifteenth internode and loading rate: 1 m s-1, respectively. The minimum and maximum values of shear strength were obtained as 0.06 MPa at fifth internode and loading rate: 4 m s-1 and 1.55 MPa at fifteenth internode and loading rate: 1 m s-1, respectively. Based on the statistical analysis, the average values of shear strength and shear consumption energy were obtained as 13.8 J from 3.19 to 19.60 J, and 0.66 MPa from o.71 to 1.03 MPa, respectively. [ABSTRACT FROM AUTHOR]

Increasing the resolution of recent satellite images has become one of the problems for image classification in scientific studies. One way to overcome this problem is to characterize the pixel being classified by parameters measuring the spatial organization of the pixels in its neighborhood. In this study, textural parameters of one-step and two-step encoded images were calculated in the form of a vector. These parameters were subject to the support vector machine classifier to decide which class image is belonging to. Results showed that the encoding method is a proper way to compress an image without losing textural information. It reduces the size of data and thereby reducing the computation time characteristics. [ABSTRACT FROM AUTHOR]

Nowadays, artificial intelligence solutions such as digital image processing and artificial neural networks (ANN) have become important applicable techniques in phytomonitoring and plant health detection systems. In this research, an autonomous device was designed and developed for detecting two types of fungi (Pseudoperonospora cubensis,Sphaerotheca fuliginea) that infect the cucumber (Cucumis sativusL.) plant leaves. This device was able to recognise the fungal diseases of plants by detecting their symptoms on plant leaves (downy mildew and powdery mildew). For leaves of cucumber inoculated with different spores of the fungi, it was possible to estimate the amount of hour post inoculation (HPI) by extracting leaves’ image parameters. Device included a dark chamber, a CCD digital camera, a thermal camera, a light dependent resistor lightening module and a personal computer. The proposed programme for precise disease detection was based on an image processing algorithm and ANN. Three textural features and two thermal parameters from the obtained images were measured and normalised. Performance of ANN model was tested successfully for disease recognition and detecting HPI in images using back-propagation supervised learning method and inspection data. Such this machine vision system can be used in robotic intelligent systems to achieve a modern farmer’s assistant in agricultural crop fields. [ABSTRACT FROM PUBLISHER]

The first stage of any vision system is the image acquisition stage. If the image has not been acquired satisfactorily, then the intended tasks for image processing and image classification may not be properly achievable. In this study, a machine vision system was developed to evaluate the performance of CCD and CMOS cameras for real-time monitoring of cucumber growth in a greenhouse by extracting image textural features. The leaf samples of cucumber crops were brought to the laboratory from the greenhouses to measure the textural features. Laboratory was consisted of a digital camera for taking the images, a LDR array for providing a uniform lightening and a computer for measuring the textural parameters from the obtained images. The objective of the current study was to select which type of camera is ideal for real-time plant health and growth monitoring systems. The effect of distance between camera and leaves for three values (30, 40 and 50cm) and the type of camera (CMOS and CCD) on the uniformity of resulted data were considered in this article. Results showed that data for 40cm distance between camera and leaves with a CCD camera had an acceptable trend for extracting image textural features. [ABSTRACT FROM AUTHOR]

An impingement jet method was employed for extracting of sunflower seeds from sunflower heads (SHs). The method was based on holding SHs with a rotating plate and extracting the sunflower seeds with the help of pressurized air-jets. Artificial neural networks (ANNs) and response surface methodology (RSM) were used to model the effects of operational parameters of impingement air-jet on performance of preliminary model of the remover machine. The operational parameters were diameter of nozzle (ND), angle of impingement (AI), distance between nozzle outlet and sunflower head (DBNS), air pressure (AP) and rotational velocity of sunflower head (RV). The final ANN model, 3-5-1, successfully modeled the relationship between three operational parameters, ND, AI and RV with removing performance of machine (RPAJSSR) with R2of 0.98 and T value of 0.96. The RSM method was applied for three different locations of SHs at the optimum AP of 7 bar. The maximum value of RPAJSSR, (57%) was obtained for ND of 8 mm, AI of 30°, DBNS of 20 mm and RV of 10 rpm at side region of SH (SRSH). Also, the minimum value (4.49%) belonged to ND of 4 mm, AI of 30°, DBNS of 20 mm and RV of 15 rpm for central region of SH (CRSH). [ABSTRACT FROM AUTHOR]

In order to eliminate some problems of traditional and mechanical methods of separating sunflower seeds from the receptacles, a new method based on impingement jets was innovated. The effect of the seeds' location, reservoir pressure, nozzle diameter, and the distance between the two nozzles on the separating area of sunflower receptacle, in three different states including, static, linear movement of sunflower receptacle, and rotational movement of nozzles were examined. Also theoretical areas of covered region by the two nozzles in the three different states were calculated. The regions separated by impingement of the air-jet were photographed and the area of the separated regions was calculated based on image processing technique. Also, for the three states, power consumption of compressor was calculated. Moreover, in each state, response surface methodology was used to find the five best optimized points. In the static state, maximum and minimum values of area of separated regions in the central, middle, and side region of sunflower receptacle were equal to 2.63 and 1.39, 3.83 and 1.96, and 4.02 and 2.12 cm2, respectively. In the linear movement state, maximum and minimum values of area of separated regions in the central, middle, and side region of sunflower receptacle were equal to 9.78 and 5.72, 16.19 and 10.02, and 17.43 and 11.15 cm2, respectively. The corresponding values for rotational movement state were 9.33 and 5.14, 128.98 and 86.12, and 241.89 and 157.65 cm2, respectively. Obtained results by variance analyzing showed that in all three states and in each region, effects of independent input factors were significant at probability level of 1%. Also in all tests, no seed was observed to be damaged due to air-jet impinging. [ABSTRACT FROM AUTHOR]

Due to the success of air-jet application in food and agricultural sciences, a new method was invented based on the impingement jets to eliminate some problems presented in mechanical methods of removing sunflower seeds from the head. When the sunflower head had linear velocity and the nozzle was fixed, the effects of the seeds’ location on the sunflower head, reservoir pressure, nozzle diameter, linear velocity of the sunflower head, and the distance between the nozzle outlet and the surface of the sunflower head on its removed area were examined. The regions removed by the impingement of the air-jet were photographed, and the area of the removed regions was calculated based on the image processing technique. The results showed that the area of the removed region increased with increasing the nozzle diameter, reservoir pressure, and distance between the nozzle outlet and sunflower head; also, the area of the removed region increased with decreasing the linear velocity of the sunflower head. The maximum value of the area of the removed region in all regions was obtained when the linear velocity, nozzle diameter, reservoir pressure, and distance between nozzle outlet and sunflower head were equal to 1 cm sec-1, 8 mm, 800 kPa, and 30 mm, respectively. The minimum value of the area of the removed region in all regions was obtained when the linear velocity, nozzle diameter, reservoir pressure, and distance between nozzle outlet and sunflower head were equal to 3 cm sec-1, 4 mm, 600 kPa, and 10 mm, respectively. [ABSTRACT FROM AUTHOR]

Two main steps in object recognition systems involve feature representation and classification. In this study, the combination of principal components analysis (PCA), linear discriminant analysis (LDA) and support vector machine (SVM) approaches were used to develop a cultivar classification system for Anthurium flower, which PCA, LDA, and SVM were applied for data reduction, feature extraction, and classification, respectively. The algorithm was tested on a database of Anthurium flower images, which included the images of 20 cultivars of the flower with different sizes, and little variations in angles of rotation (from -π/12 to π/12) that flowers are placed under the camera, and lighting conditions. Results were evaluated from the two points of view of classification accuracy and computation time, and the algorithm had remarkable results when trained using suitable multi-class SVM classifier features, as it is possible to increase the classification accuracy up to 99.5% using an RBF kernel function and Sparse random multi-class codding method. Cultivar recognition of flowers is an important step for subsequent flower real-time grading tasks and such algorithms could be used for these procedures. [ABSTRACT FROM AUTHOR]

Some physical and mechanical properties of sunflower seeds were studied. The measured parameters were linear dimensions, thousand grain mass, geometric mean diameter, sphericity, surface and projected area, volume, shape parameters (such as flakiness ratio and elongation ratio), true and bulk densities, porosity, angle of repose and static coefficient of friction of the Shamshiri variety in the moisture range from 6.3 to 20% (w.b.) using standard methods. Average rupture force, deformation and absorbed energy at rupture point of the sunflower seeds under compression as well as the extent of physical damage to seeds due to impact were also determined over a range of moisture contents between 1.8% and 20.3% (w.b). The results showed a variation of 14.32 to 31.00 mm for length, 4.73 to 9.82 mm for width and 2.36 to 6.67 mm for thickness of sunflower seeds. The values of the thousand grain mass, seed volume, true density, bulk density and porosity of sunflower seeds were between l49.81-167.77g, 99.05-628.9 mm3, 444.39-521.78 kg/m3, 269.06-275.57 kg/m3 and 39.09-17.18% respectively. The rupture force, deformation, and absorbed energy increased with increase in moisture content from 1.8 to 14.5%, while decreased with further increasing of moisture content from 14.5 to 20.3%. The mean value of percentage of physically damaged seeds increased from 2.75 to 10.81% with increasing the impact velocity from 40.8 to 62.3 m/s. In both impact orientations, the total damaged seeds increased with increase in impact velocity for all moisture contents of seeds. [ABSTRACT FROM AUTHOR]

To design a sunflower machine for removing seeds from sunflower head (SH) based on air-jet impingement, preliminarily model of such machine was designed, constructed and evaluated. Effects of the seed location, angle of impingement, distance between nozzle outlet and sunflower head, and rotational velocity of sunflower head on percentage of extracted seeds were examined. In order to examine the effects of air-jet parameters on percentage of removed seeds in different locations of seed on sunflower head, sunflower heads were divided into three regions, namely central region, middle region and side region. Results indicated that in all three regions, with increasing rotational velocity from 10 to 30 rev/min, percentages of removed seeds from the SH decreased. Results also indicated that in all three regions, with increasing distance between nozzle outlet and SH surface from 10 to 20 mm and decreasing distance between nozzle outlet and SH surface from 40 to 20 mm, percentage of removed seeds from the SH by air-jet increased. Results indicated that in side region, with decreasing angle of impingement from 90% to 30%, of removed seeds from the SH by air-jet increased and in middle and central regions, with increasing angle of impingement from 30° to 60° and decreasing angle of impingement from 90° to 60°, percentages of removed seeds from the SH by air-jet increased. Also in all tests, no seed damaged due to air-jet impinging was observed. [ABSTRACT FROM AUTHOR]