Design and Construction
M. Teimorzadeh; J. Baradaran Motie; A. Rohani; Y. Selahvarzi
Abstract
IntroductionNeglecting the water requirements of trees can result in inefficient irrigation practices, leading to either water wastage or drought stress. Effective irrigation management necessitates precise information on the quantity and pattern of water consumption by trees. To achieve optimal irrigation, ...
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IntroductionNeglecting the water requirements of trees can result in inefficient irrigation practices, leading to either water wastage or drought stress. Effective irrigation management necessitates precise information on the quantity and pattern of water consumption by trees. To achieve optimal irrigation, a reliable method for quantifying plant water needs is crucial, ensuring that trees avoid drought stress. Current methods for assessing tree water requirements often focus on specific components, such as stems or leaves. These techniques typically require manual intervention, which is time-consuming and resource-intensive, thereby restricting their application mainly to research environments.Materials and MethodsA sap-flow meter device was developed to generate a heat pulse in a tree trunk at 15-minute intervals. The device comprises measuring probes, a processing unit, and a data logger. For a comprehensive evaluation, device probes were positioned on the trunk of a Ficus benjamina tree within a controlled environment at two distinct heights. The resulting sap flow through the vascular tissue was then compared to data obtained using the lysimetric method. The Ficus benjamina tree, with a trunk diameter of 3.5 cm and a height of 196 cm, was prepared during the summer of 2022. By measuring the rate of heat pulse dissipation and applying heat transfer principles, sap flow is estimated under the assumption that heat transfer occurs primarily through the sap flow within the vascular tissue. This estimation was achieved using the heat ratio method (HRM).The trunk was triple drilled with holes of 1.5 mm in diameter and 25 mm in depth. Following drilling, the probes were inserted into these holes (Figure 1). To prevent heat transfer from the probes to the surrounding environment, the trunk was wrapped with glass wool insulation. To assess the reliability of the device, the lysimetric method was employed to measure tree transpiration. For this purpose, the soil surface of the pot was covered with cellophane to ensure that evaporation and weight loss of the pot occurred exclusively through the tree's leaves. Hourly measurements of the pot's weight were taken using a digital scale. Changes in the pot's weight indicate the amount of water evaporated, which corresponds to the water transpired by the tree through its vascular tissue.Results and DiscussionThe results showed that the sap-flow meter device slightly overestimates the tree's water consumption compared to the values obtained using the lysimetric method. Sap flow and transpiration follow a similar trend, both escalating throughout the day and reaching their highest levels in the early afternoon. This value reached 17.98 ml h-1 for sap flow and 16 ml h-1 for transpiration (by lysimetric method), followed by a rapid decrease in the late afternoon as the air cooled down. In addition, the results of device measurements showed that spraying water on the leaves lowers both the rate and volume of sap flow. When the canopy becomes wet, the evaporation of water from the leaf surface leads to a drop in the temperature, which in turn significantly slows down the flow of sap.The v1/v2 ratio is not constant over time, making it crucial to choose the right starting point for measurements to ensure effective data acquisition during the device's operational cycle. It is essential to measure (by the device) the difference between temperature probes 40 seconds after heat pulse generation. The sap flow and transpiration followed a similar trend during the experiments. The sap flow and transpiration increased throughout the day, peaking in the early afternoon. On the first day, sap flow reached 17.98 ml h-1, while the second day recorded an even higher rate of 19.75 ml h-1. Correspondingly, the transpiration measured using the lysimetric method peaked at 16 ml h-1, followed by a rapid decline in the late afternoon.ConclusionThe results obtained from the developed device indicate several key findings. Sap flow and transpiration exhibit a similar trend during the test period, with the estimated sap flow value being approximately 30% higher than that obtained using the lysimetric method. The device effectively demonstrated the impact of surface irrigation; spray irrigation influences the sap flow rate such that when the canopy becomes wet, the sap flow rate decreases significantly. Additionally, sap flow and transpiration are positively correlated with air and canopy temperatures, and negatively correlated with relative humidity. Following calibration, the results show that the heat pulse method can accurately and effectively measure sap flow in the vascular tissue of trees.
Design and Construction
E. Vahedi Tekmehdash; H. Navid; H. Ghasemzadeh; H. Karimi; M. Javani Holan
Abstract
IntroductionThe livestock sector excels in the production of dairy and meat products. These products, serving as vital sources of animal protein, hold a significant position in household diets. The significance of these two products in the food basket has heightened awareness around animal health. Regularly ...
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IntroductionThe livestock sector excels in the production of dairy and meat products. These products, serving as vital sources of animal protein, hold a significant position in household diets. The significance of these two products in the food basket has heightened awareness around animal health. Regularly tracking rumination time serves as a vital and insightful measure to obtain information about the rest and overall health of an animal. This information enables prompt intervention for health or nutritional issues, allowing for earlier management adjustments and veterinary care to effectively combat the onset of disease. In the past, rumination was usually monitored through visual observation by on-site staff or through videos recorded by cameras installed on the livestock. Nowadays, the growing scale of livestock farms makes it impractical to effectively monitor the animals individually. The traditional method of visual observation demands the continuous presence of livestock professionals and is extremely time-consuming. Currently, sensors and digital technologies have become important tools for accurate animal husbandry, enabling real-time monitoring of rumination. A review of the research in the field of precision animal husbandry shows that many efforts are being made to develop precision monitoring sensors to overcome the mentioned problems. Continuous and automatic monitoring of animal behavior through sensors can offer valuable insights into nutrition, reproduction, health, and overall well-being of dairy cows.Materials and MethodsIn this research, an accelerometer-based sensor was developed and used in the precision agriculture laboratory of Tabriz University, Iran. The sensor was installed in three different positions on the cow's body to collect data. Important factors were calculated from the raw data, and the modeling was done using the logistic regression method. The logistic regression model was trained to distinguish rumination from the other cow's behaviors. The developed model was evaluated using the receiver operating characteristic (ROC) curve, and three other evaluation criteria: precision, sensitivity, and F-score. Finally, the performance of the final model and sensor was evaluated in the field for a few days.Results and DiscussionAfter calculating the evaluation criteria for different calculation factors, four optimal factors were finally selected from the 50 arrays. Muzzle mode was found to be the best place to install the sensor. Logistic regression was the best modeling method for binary classification between rumination and other behaviors. The evaluation criteria of the model in the proposed sensor are the highest, and the values of sensitivity 88%, accuracy 94%, and F-score 91% were obtained through logistic regression analysis. The final test results of the model revealed that the sensor demonstrated an impressive detection capability of 89.47%. Furthermore, the developed system exhibited strong alignment with the actual field observations, highlighting its effectiveness and reliability. Finally, the results of the current study were compared with other studies in the literature.ConclusionThis study investigated recording and monitoring rumination behavior using an accelerometer, which can help prevent financial losses in cattle farms. After examining different mounting locations of the sensor, it was found that the muzzle position provided more accurate detections than the other mounting locations. The final model was created using the statistical factors and the calculation of the evaluation criteria. The results showed that the proposed model provided more correct diagnoses and achieved the optimal solution.AcknowledgmentWe would like to express our gratitude to the Khalat Poushan Cattle Farming Complex of the University of Tabriz, Iran, its professors and staff for supporting this project, and for their commitment to promote animal husbandry science.
Design and Construction
N. Loveimi; A. Azizi; A. Kaab; A. Neisi
Abstract
IntroductionSubsoiling is a critical tillage operation for many crops, particularly sugarcane, due to the impact of agricultural machinery traffic and its significance in managing heavy-textured and compacted soils. Given the extensive size of sugarcane fields and the time-intensive nature of subsoiling ...
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IntroductionSubsoiling is a critical tillage operation for many crops, particularly sugarcane, due to the impact of agricultural machinery traffic and its significance in managing heavy-textured and compacted soils. Given the extensive size of sugarcane fields and the time-intensive nature of subsoiling operations, the application of intelligent control techniques for monitoring and managing these processes is of considerable importance. Currently, subsoiling operations are monitored using manual gauges. This approach involves collecting a limited number of samples per hectare, typically after the operation is completed, which makes it nearly impossible to implement real-time corrections. To address this limitation, the development and implementation of a depth measurement system offer a promising solution. Such a system enables real-time observation of working depth by both the operator, via an on-screen display, and by a remote observer through an online platform. This capability allows for immediate adjustments during the operation, ensuring greater precision and efficiency. Furthermore, by integrating recorded depth data with geospatial information, it becomes possible to generate detailed maps illustrating depth variations across the field. These maps can serve as valuable tools for further evaluations, such as performance monitoring in areas where subsoiling depth deviates from the desired range, either being too shallow or excessively deep. This technological advancement has the potential to significantly enhance the accuracy and effectiveness of subsoiling operations in modern agricultural practices.Materials and MethodsThis study focused on the design, development, and evaluation of a depth measurement system for a subsoiler attached to a track-type tractor, specifically tailored for sugarcane fields. The system not only provided real-time depth display but also recorded the location and transmitted it online. The research employed three distinct depth measurement techniques and was conducted using a randomized complete block design with split plots. The main plots are the three depth measurement techniques: based on the angles of the driving profiles of the subsoiler shanks (T1), the laser distance measurement method (T2), and the ultrasonic distance measurement method (T3), and sub-plots are depth ranges at three levels: 0-30 cm (R1: surface range), 30-60 cm (R2: mid-range), and 60-90 cm (R3: deep range). Initially, we calculated the absolute difference between the depths recorded by the system and those measured manually with a rod at each location. Following this, we analyzed key statistical indicators, including the average, standard deviation, and the minimum and maximum of errors, for comparison.Results and DiscussionThe results showed that the depth measurement error was significantly influenced by the technique employed. The angle technique yielded the lowest average error of 1.91 cm, while the ultrasonic technique resulted in the highest average error of 3.83 cm. Across all depth ranges, statistical indicators for depth error were significant. Specifically, within these ranges, the deep range exhibited an average depth error of 2.33 cm, and the surface range had an average error of 3.65 cm. Statistical analysis revealed that only indices related to minimum and maximum errors for interactions between factors were significant. The lowest minimum error value (0.05 cm) was observed with the angle technique at deeper depths, whereas the highest minimum error (0.34 cm) occurred with ultrasonic measurements at shallower depths on surfaces. Similarly, maximum errors followed this trend: The lowest maximum error (3.21 cm) was associated with angle measurements at deeper depths, while ultrasonic measurements on surfaces yielded a higher maximum error (8.63 cm). Both laser and ultrasonic techniques consistently demonstrated greater errors across all three depth ranges compared to angle-based methods. This discrepancy may be attributed to inaccuracies inherent in rangefinders when their beams encounter obstacles like clods or pits during field operations. Notably, as working depths increased across all measurement techniques, errors in depth measurement decreased significantly due to reduced vibrations from subsoiler devices at greater depths, thereby minimizing vibration-related inaccuracies.ConclusionThe results indicate that the depth measurement technique based on the angles of the driving profiles of subsoiler shanks exhibits superior accuracy in determining the working depth of subsoilers mounted on tractors, particularly during sugarcane field operations. The laser distance meter technique ranked second in terms of accuracy, while the ultrasonic distance meter method demonstrated the least precision. Notably, as working depths increased, reduced vibrations during operation were observed, leading to enhanced accuracy in depth calculations across all techniques. This improvement is attributed to decreased mechanical disturbances at greater depths. Overall, measurements within deeper ranges achieved higher levels of accuracy compared to those at shallower surface ranges. This trend suggests that operational conditions and device stability play significant roles in optimizing measurement accuracy.
Design and Construction
A. Sadin; M. H. Aghkhani; M. A. Ebrahimi-Nik; J. Baradaran Motie
Abstract
IntroductionPlanting rice seedlings in the main field followed by periodic or intermittent irrigation is often considered a form of dry farming. Research suggests that flood irrigation in rice cultivation is primarily favored by farmers for its ability to control weeds and ensure a reliable water supply, ...
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IntroductionPlanting rice seedlings in the main field followed by periodic or intermittent irrigation is often considered a form of dry farming. Research suggests that flood irrigation in rice cultivation is primarily favored by farmers for its ability to control weeds and ensure a reliable water supply, rather than necessarily enhancing rice quality or yield. Depending on the rice variety, intermittent irrigation can sometimes improve both the quality and yield per unit area. The transplanting process in this method can be carried out manually without machinery or through mechanized methods using a planter.Materials and MethodsConventional rice transplanters designed for use in flooded land are not suitable for transplanting in dry land farming due to technical constraints. Therefore, it is necessary to develop a specialized rice transplanter tailored for such soil condition. This transplanter encompasses essential components, including a furrow opener, coverer, seedling storage tank or tray, seedling mechanism (distributor), seedling transfer mechanism (seedling transport piston), end separator for seedlings in the soil, power transmission system, depth adjustment shoe, and main and sub chassis. To evaluate the planter's performance, various parameters were assessed, including the percentage of lost plants, the average vertical angle of plant orientation, the average spacing between plants in the crop row, and the average number of seedlings per plant. Moreover, a factorial randomized block design was employed, with three replications for each level of the independent variables. The independent variables were forward speed (X1) at three levels of 0.25, 0.5, and 1 m s-1, planting depth (X2) at three levels of 4, 8, and 12 cm, and the size of the outlet opening of the seedling tray (X3) in three levels of 10, 15, and 20 mm.Results and DiscussionThe developed single-row planter features key specifications, including a working width of 250 mm, a power requirement of 0.57 kW, a theoretical field capacity of 0.06 ha h-1, and a field efficiency of 66.67%. The research findings revealed that forward speed, planting depth, and outlet opening size, along with their interactions, significantly impact the percentage of lost plants at the 99% confidence level. Among the three levels of forward speed (X1), the best speed level is 0.25 m s-1, as it results in the lowest percentage of lost seedlings. As the forward speed increases, the percentage of lost seedlings increases. The lowest percentage of lost plants (Y1) occurs at the planting depth of 8 cm and an outlet opening size of 20 mm. Furthermore, forward speed, planting depth, and their interaction have a noteworthy influence on the vertical angle of plants are established, at the 99% confidence level. With the increase of forward speed and planting depth, the average vertical angle of seedling establishment deviates from the vertical position. The forward speed of 0.25 meters per second and the planting depth of 8 cm show the best results for the establishment of seedlings. The sole factor affecting the spacing between plants in the row is the forward speed. The size of seedling tray’s outlet opening significantly affects the number of seedlings per plant at the 99% confidence level, while planting depth affects it at the 95% confidence level.ConclusionGiven the recent water crisis, adopting the dry rice farming method and using transplanters offers a viable solution for managing and conserving water in agriculture. Implementing dry planting with a custom-made transplanter yields several benefits, including reduced water consumption, lower cultivation costs, improved soil aeration, increased efficiency, and simplified planting processes. Utilizing this transplanter is an effective strategy to decrease both the time and expenses related to transplanting, while also mechanizing rice planting in dry fields.
Design and Construction
M. Safari; P. Ghiasi; A. Rohani
Abstract
In Iran, more than 50,000 hectares of sunflowers (oil and nuts) are cultivated annually. Conventional grain combine harvesters are not compatible with the unique characteristics of sunflowers, leading to significant grain losses during harvesting. Therefore, it is currently being harvested manually. ...
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In Iran, more than 50,000 hectares of sunflowers (oil and nuts) are cultivated annually. Conventional grain combine harvesters are not compatible with the unique characteristics of sunflowers, leading to significant grain losses during harvesting. Therefore, it is currently being harvested manually. Manual harvesting increases labor hardships, energy and time consumption, and production costs. In this research, to harvest sunflower seeds, modifications were made on conventional head of a combine harvester (John deer 1055) to allow simultaneous harvesting, threshing, and cleaning of the sunflower seeds. After designing and fabricating the accessory, the improved head in field conditions was evaluated and compared with conventional harvesting methods. The field evaluation of the improved head was based on a randomized complete block design with three replications. The treatments involved three different harvesting methods: 1) using a modified combine head, 2) employing a combine equipped with pan attachment, and 3) manual harvesting. In each of the machine treatments, beating and cleaning units were set up for sunflower harvest. The results showed that there was a significant difference between the treatments concerning machine losses, field capacity, and harvesting costs, all at the 5% significance level. In the modified combine, combine with pans attachment, and manual method, combine losses were 0.72, 4.85, and 6%, and field capacity was 1.2, 1.13, and 0.12 ha h-1, respectively. The profit-to-cost ratio was 13.97, 13.3, and 3.01, respectively. The grain breakage percentage was 3, 3.3, and 0.56, respectively. According to the results, due to lower losses, appropriate field capacity, and lower harvesting costs, the use of John deer 1055 combine with the modified head is recommended for harvesting of the sunflower.
Design and Construction
B. Abbasian; M. E. Khorasani Ferdavani; H. Zaki Dizaji
Abstract
IntroductionThis study investigated the development and evaluation of an automatic feeder control system for sugarcane planters. The primary objective was to address limitations in existing machines and enhance their performance by introducing precise control of cane feeding.Materials and MethodsThe ...
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IntroductionThis study investigated the development and evaluation of an automatic feeder control system for sugarcane planters. The primary objective was to address limitations in existing machines and enhance their performance by introducing precise control of cane feeding.Materials and MethodsThe automatic feeder control system was equipped with three types of sensors, including a Load Cell Sensor that directly measures the weight of sugarcane on the feeder table. This feature provides a real-time assessment of cane availability. The Hydraulic Oil Pressure Sensor monitored the pressure within the hydraulic system that drives the feeder mechanism. Variations in pressure served as an indirect measure of the force applied to the cane during the feeding process. The Ultrasonic Distance Sensor employed ultrasonic waves to estimate the distance between the sensor and the sugarcane pile. Nevertheless, some limitations concerning accuracy and response time were identified. A microcontroller served as the central processing unit, receiving sensor data and generating control signals to regulate the feeder mechanism. This allowed for automation and eliminated the need for a manual operator. The performance of the automatic feeder control system was evaluated against a manual control method operated by a human.Results and DiscussionThe evaluation focused on three key aspects: cane spillage, planting quality, and control stability. Cane Spillage: the amount of sugarcane inadvertently dropped during the planting process. Automatic control methods using a load cell and hydraulic oil pressure sensor reduced spillage similarly to manual control, averaging approximately 8.8 t ha-1. The ultrasonic sensor resulted in significantly lower spillage, achieving 7.4 t ha-1. However, its limited accuracy and responsiveness led to undesirable gaps between the planted canes. Planting Quality: The implementation of automatic control techniques utilizing load cells and hydraulic oil pressure sensors successfully ensured uniform spacing between planted canes, achieving results comparable to traditional manual methods. Due to its shortcomings, the ultrasonic sensor created gaps between the planted canes, undermining the overall quality of the planting process. Control Stability: The method utilizing hydraulic oil pressure sensors exhibited limitations in maintaining consistent control under varying operational conditions. This stemmed from temperature-dependent changes in oil viscosity, which affected the pressure readings and ultimately the control signal. Based on the evaluation results, the load cell control method emerged as the most favorable option for automatic feeder control. It delivered performance that matches manual control in terms of cane spillage reduction and planting quality, all while eliminating the need for an operator. The hydraulic oil pressure sensor method, although effective in some aspects, presented challenges due to oil viscosity variations. The ultrasonic sensor showed promise for reducing spillage; however, it ultimately fell short due to its inability to accurately and swiftly detect the availability of cane, resulting in gaps between planted canes. A separate assessment was carried out to compare manual cultivation with an automatic control method based on weight measurements using a load cell. This evaluation revealed significant differences (p < 0.01) in billet weight, the number of billets utilized, and one-sided gaps between the two methods. However, no significant difference was observed in terms of two-sided gaps.ConclusionThis study successfully designed and implemented an automatic feeder control system for sugarcane planters. The load cell control method emerged as the most effective solution, successfully eliminating the need for operators while ensuring high standards of planting quality and efficiency. Additional research could explore advancements in sensor technology and control algorithms to further enhance the performance of automatic feeder control systems.AcknowledgmentThe authors would like to express their gratitude to the Managing Director of Farabi Agro-Industrial Company and its staff, as well as the technical staff of Poya Sazan Sabz Avane Company, who cooperated in the preparation and evaluation stages of the system. Vice Chancellor for Research and Technology of Shahid Chamran University of Ahvaz, Iran: financial support under the special research grant number SCU.AA98.505.
Design and Construction
M. Rezaei; J. Khodaei; B. Astinchap
Abstract
IntroductionDue to the increasing need for agricultural products, protection of products against pathogens and preventing them from being wasted is important. Studies on droplet charging systems result in the reduction of chemical usage and an increase in the deposition of droplets on the target. Conventional ...
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IntroductionDue to the increasing need for agricultural products, protection of products against pathogens and preventing them from being wasted is important. Studies on droplet charging systems result in the reduction of chemical usage and an increase in the deposition of droplets on the target. Conventional sprayers used in Iran have numerous disadvantages such as drift, environmental pollution, lack of complete and homogeneous coverage of the spraying surface, phytotoxicity, and crop losses. Therefore, evaluation of new spraying methods and using a variety of electrical sprayers as alternatives to conventional spraying is essential. This study aims to design, construct, and optimize the performance of the electrodynamic head of an atomizer motorized knapsack sprayer, and study the effects of the angle of the target position, spraying distance, and wind speed on the performance of the electrodynamic sprayer.Materials and MethodsExperiments were performed in an agricultural machinery workshop at The Department of Biosystems Engineering, the University of Kurdistan, Iran, with an atomizer motorized knapsack sprayer equipped with an electrodynamic head. The effect of some factors including wind speed, spraying angle, and spraying distance on deposition, coverage percentage, and uniformity of spraying were investigated. These effects were investigated to determine the uniformity coefficient of total spraying. Design Expert 8.0.6 Trial software was used to design the experiments based on central composite design and to analyze the data. The investigated factors and levels were: the distance of nozzles from the target (at three levels of 2, 4, and 6 m), the angle of the target position (at three levels of 0, 45, and 90 degrees), and wind speed (at three levels of 2.5, 3, and 3.5 m s-1). Water-sensitive paper cards were used to evaluate the quality of the spraying. The cards were scanned and magnified with an Olympus SZX12 Stereo Microscope equipped with an objective lens of X1 and a total magnification of 7X. The characteristics of droplet size were determined using Mountains Map Trial and Deposit Scan software.Results and DiscussionThe maximum value of the total spraying uniformity coefficient was equal to 1.95 for the spraying angle of 0 degrees, the distance of 6 meters, and the speed of 3.5 meters per second. Meanwhile, the lowest value of the spray uniformity coefficient of 1.18 was obtained for the test conditions of 90 degrees, distance of 2 m, and speed of 2.5 m s-1, respectively. Based on analysis of variance for the two-factor interactions model (P-value less than 0.0001, explanation coefficient 0.9383, absolute explanation coefficient 0.910, standard deviation 0.0590, and coefficient of variation 3.790%). It can be stated that this model is highly accurate in predicting the uniformity of the total spraying, and the linear components of spraying angle and spraying distance, as well as the interaction of spraying angle × spraying distance and spraying distance × wind speed, significantly affect the uniformity of the total spraying (p<0.05). Nevertheless, the linear component of wind speed and the interaction between wind speed and spraying angle had no significant effect on the changes in the uniformity coefficient of the total spray. According to the variance analysis table (F-values), spraying distance has a far greater effect on the spraying uniformity coefficient than the spraying angle.It has been observed that the spraying uniformity coefficient will increase by increasing the spraying distance and decreasing the spraying angle. It can also be stated that the linear components of spraying angle and spraying distance, the interaction component of spraying angle × spraying distance, and the square power of the components of spraying distance and wind speed have a significant effect on surface coverage. The values of R2, Adj-R2, CV, and PRESS for the model adapted to the test data of leaf surface coverage percentage were obtained as 0.9929, 0.9865, 4.87%, and 188.61, respectively.Among the three input variables, the spraying distance has the greatest effect on the coverage of water-sensitive papers. At larger spraying angles, especially 90 degrees, the coverage decreased with the increasing distance. At spray angle of 90 degrees, by increasing the distance from 2 to 4 m, the spray uniformity coefficient increased from 1.18 at a wind speed of 2.5 m s-1 to 1.84 at a wind speed of 3.5 m s-1. However, at smaller spraying angles (for example zero-degree angle), at first, the spraying coverage increases with the increase of the spraying distance from 2 to 3 m and then sharply decreases afterward. According to the contours of spray coverage, in the spray distance range of 4 to 6 m and regardless of wind speed, the spray coverage does not vary with the increase of the spraying angle (p< 0.05). Meanwhile, in the spray distance range of 2 to 4 m, with the increase of the spraying angle, the spraying coverage increases significantly (p<0.05). Overall, increasing the distance between the sprayer and the target decreased the surface coverage on the target, and in electrodynamic spraying, the uniformity of particle deposition on the underside of the target was relatively the same as on the upper side.ConclusionTo improve the performance of the atomizer motorized knapsack sprayer, an electrodynamic spraying head was designed and built, and its performance was optimized using the response surface method (RSM) with a central composite design. During the research process, the influence of the independent parameters such as the distance between the nozzle and the target, the angle of the target position, and the wind speed on the variables including spraying uniformity, the percentage of the spraying coverage, and the percentage of changes in the total spraying coefficient were discussed and investigated. The results of the research led to the determination of the 3.5 m s-1 wind speed, 2.5 m sprayer distance, and 90 degrees spraying angle with 0.792 desirability, which were considered as the optimal performance conditions of the electrodynamic spraying head. The results of laboratory validation for optimal conditions show that the uniformity of total spraying indicated by the total relative span factor (RSFT) and the percentage of spraying coverage (Cov) are equal to 1.65 and 28.27%, respectively.
Design and Construction
P. Ghiasi; M. Salatin; R. Soon; S. M. Mir Esmaeili; K. Pirvandi; Gh. Najafi
Abstract
IntroductionThe world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural ...
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IntroductionThe world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural sector. In Iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. The costs and time required for manual harvesting are additional obstacles. Given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process.Material and MethodsIn designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. The advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. One of the goals of designing this machine is to perform harvesting operations for two row spacing’s - 80 and 160 cm. To achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. Moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. Therefore, a transfer mechanism was designed and built to move the cut products to the trailer. Independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. Dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity.Results and DiscussionThe results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. The difference in harvest efficiency is significant at a 1% probability level. A star cutting blade provides higher efficiency than a 40-teeth cutting blade. The rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. However, the inner parts of the rods reel are empty, and the plant can fall to the ground. Additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. Another essential parameter when identifying and evaluating a harvesting machine is crop damage. Some plants get crushed and torn due to the impact on metal components. This situation reduces the quality of the harvested product, leading to a decline in the final product's price. The star-cutting blade causes more leaf rupture. In contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. However, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut.ConclusionBased on tests conducted for eight different positions of the harvester, it was observed that the G test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h-1, and only 1.34% peppermint leaf damage. Therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. However, new tests should be conducted on other products like lavender and those with strong stems.
Design and Construction
S. Naderi Parizi; R. Alimardani; M. Soleimani; H. Mousazadeh
Abstract
IntroductionActivated carbon has a wide range of applications as a porous material in the liquid or gas phase adsorption process. The physical process of activated carbon production is divided into two stages thermal decomposition and activation. In this study, only the activation stage has been studied ...
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IntroductionActivated carbon has a wide range of applications as a porous material in the liquid or gas phase adsorption process. The physical process of activated carbon production is divided into two stages thermal decomposition and activation. In this study, only the activation stage has been studied because it is very important in the properties of activated carbon being produced.The production of activated carbon from horticultural waste not only leads to cheap production and supply of many industrial and environmental necessities but also reduces the amount of the produced solid waste. Iran produces about 94,000 tons of pistachio husk annually, which is a good raw material for the production of activated carbon. The profitability index of activated carbon production in Iran is equal to 3.63, which in the case of export, the profitability index will be tripled.Studies have shown that temperature, period, and activation gas flow are the key factors affecting burn-off and iodine number during activated carbon production. Among the various activators tested, steam was found to be the most efficient, with the fastest activation time. For pistachio crops, the minimum iodine number required for economic efficiency is 600 mg g-1, while the highest specific surface area according to the BET test is 1062.2 m2 g-1.Materials and MethodsA Mannesmann tube made of 10 mm thick steel was used to construct the rotating reactor. To minimize heat loss during operation, the kiln body was insulated with a ceramic blanket capable of withstanding temperatures up to 1400°C. The kiln had a length and diameter of 190 cm and 48 cm, respectively, and operated at a temperature of 600°C, requiring approximately 25 kWh of energy for heating. CATIA V5 R21 software was employed to design the device, while ANSYS R20 software was used for thermal and mechanical analysis. The rotary reactor was identified as a critical component due to the high levels of thermal and mechanical stress it experiences. To address these issues, a thermal and fluid analysis was conducted, followed by a mechanical analysis using the results from the prior step. Subsequently, experimental tests were performed on the actual model, and the results were analyzed using statistical methods, including the T-student test in IBM SPSS software.The central heating unit and its surroundings were modeled using ANSYS CFX to obtain valuable information on fluid velocity, radiant properties, and heat transfer within the kiln and surrounding area at an operating temperature of 650°C. The analysis revealed uniform steam flow velocity between the kiln and the heating unit. To accommodate longitudinal expansion resulting from heat stress, taller rollers were employed to allow freedom of movement in that direction, while the lateral movement was unrestricted. This arrangement allows the reactor length to increase under varying temperatures. The reactor's end was designed with grooves and pressure plates, incorporating abrasion and compression plates made from refractory fibers to effectively seal the device. Furthermore, telescopic movement of the parts compensates for expansion effects.Results and DiscussionThe operating temperature of the system was gradually increased to reduce thermal stresses in the reactor shell. This led to a maximum increment in a longitudinal increase of 11.75 mm. Results from five sets of experimental tests and five software analyses demonstrated no significant differences between the experimental and analytical results at a significance level of 5%. Based on the thermal contour analysis, the thickness of the insulation layer was determined to be 5 cm. To control the operating temperature of the device, two methods were employed: adjusting the flame length of the burner and using different types of exhaust outlets. These measures effectively reduced thermal stress on the device.ConclusionThermal and mechanical analysis were useful methods for predicting heat distribution, thermal stresses, and potential dimensional changes in the activated carbon reactor. To compensate for possible alterations in the reactor's length and diameter, abrasive plates and friction washers were implemented. Careful control of fuel input to the burner and regulation of exhaust gas flow helped effectively reduce thermal stresses on the device.
Design and Construction
A. Mohammadi; K. Kheiralipour; B. Ghamari; A. Jahanbakhshi; R. Shahidi
Abstract
IntroductionThe permissible exposure time to vibration for the operator is one of the key factors in maintaining the operator's health while optimizing machinery and equipment. The tractor studied was the ITM475, manufactured in Iran. The purpose of this study was to calculate the operator's permissible ...
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IntroductionThe permissible exposure time to vibration for the operator is one of the key factors in maintaining the operator's health while optimizing machinery and equipment. The tractor studied was the ITM475, manufactured in Iran. The purpose of this study was to calculate the operator's permissible vibration exposure time while using the tractor to ensure the driver can maintain good bodily health.Materials and MethodsIn this study, experiments were conducted using a 3-axis vibration meter based on the ISO 2631 standard. The obtained data were analyzed through a factorial experiment using 18 treatments and 3 replications. The factors studied were engine rotation speed (at three levels of 1000, 1500, and 2000 rpm), road type (dirt and asphalt), and gear position (at three levels of 1, 2, and 3).Results and DiscussionVarious total vibration models were obtained for the tractor, and their determination coefficient varied from 90.11% for gear No. 3 on an asphalt road to 100% for gear No. 1 on an asphalt road and gear No. 2 on a dirt road. The maximum whole-body vibration, and consequently the minimum permissible exposure time, was observed for gear No. 3 at an engine rotation speed of 2000 rpm on a dirt road, which was 1.49 and 1.16 hours, respectively.ConclusionThe maximum whole-body vibration experienced during an 8-hour tractor-driving session was measured at 0.85 m s-2. It is important to note that the permissible exposure time decreases as vibration levels increase, and it reaches a limit of 1.16 hours. To ensure drivers adhere to these permissible exposure times across various driving conditions, measures must be implemented to reduce tractor vibration and minimize its transmission to the driver. By reducing overall tractor vibration and minimizing its impact on the driver, it becomes possible to increase the permissible exposure time for drivers.
Design and Construction
M. Tahmasebi; M. Gohari; A. Sharifi; A. Hedayatipour
Abstract
Soil compaction can be naturally occurred or can be machinery-induced. Subsoiling is often applied to loosen soil compaction and decrease soil strength to levels that allow for root development and growth. Variable-depth subsoiling which modifies the physical properties of soil only where the tillage ...
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Soil compaction can be naturally occurred or can be machinery-induced. Subsoiling is often applied to loosen soil compaction and decrease soil strength to levels that allow for root development and growth. Variable-depth subsoiling which modifies the physical properties of soil only where the tillage is required for crop growth has the potential to reduce labor, costs and fuel, and energy requirements. Since this study aimed to perform subsoiling operations with variable depth, the variable-depth tillage (VDT) tool was developed. A pneumatic multi-nozzles sensor has been used to simultaneously predict the depth of a soil layer in three depths (15, 30, and 45 cm), and send a signal to control the depth of the VDT tool. Evaluation of the VDT tool system was performed by two methods namely static and dynamic tests. In static evaluation, the system response time was measured to reach 95% of the proposed depths. The dynamic evaluation of the tool was accomplished in two steps in the field. The amount of fuel consumption and the travel distance of the tool tine to reach the desired operation depth were measured and compared with the common subsoiler (when the depth control was OFF). The average fuel consumption by using the variable-depth tillage tool decreased by 17.36% compared to the constant depth. Furthermore, the pneumatic sensor tine penetrated into the soil perfectly and sent the control signal to the control unit of the VDT tool in real-time, and the VDT tool loosened the soil at the exact depths sent by the sensor.
Design and Construction
I. Ahmadi; M. Golabadi; A. R. Eghtedari
Abstract
IntroductionAccording to FAO, gherkin and cucumber have been cultivated in about 2.23 million hectares of farmlands around the globe, and about 78000 hectares of Iran agricultural fields have been devoted to gherkin and cucumber cultivation. However, large amounts of the cucumber seeds required in Iran ...
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IntroductionAccording to FAO, gherkin and cucumber have been cultivated in about 2.23 million hectares of farmlands around the globe, and about 78000 hectares of Iran agricultural fields have been devoted to gherkin and cucumber cultivation. However, large amounts of the cucumber seeds required in Iran have been imported from abroad. Fortunately, some Iranian agricultural companies have been focused on seed production recently. Therefore, there is an opportunity to develop seed production equipment such as seed extracting machines.There are two types of cucumber seed extractors: bulk seed extractor and single fruit extractor. The bulk seed extractor is suitable for extraction of large amounts of seed on the farm, while the single fruit extractor is suitable where seed production is limited to greenhouse seed-producing facilities which are mostly used for controlled pollination of the crop.Due to the high price of imported seed extractors, especially after increasing the price of foreign currencies, production of these machines within the country is economically rational; therefore, the aim of this research is to develop and evaluate a single fruit cucumber seed extractor for small and medium-size seed-producing greenhouses.Materials and MethodsThe cucumber seed extractor was designed semi-automatically. The criteria for designing the machine were as follows: 1- usage of the single fruit seed extraction method, 2- the possibility of simultaneous usage of two operators, 3- automatic discharge of the extracted seeds, 4- the possibility of the height variation of the machine, 5- the possibility of the emergency shutdown of the machine, 6- the possibility of the angular velocity variation of the machine helix.The working element of the machine was the rotating helix that can extract the fruit seeds and leave the fruit's outer skin mostly intact for easy disposal of fruit remains from the greenhouse. A 1 hp, 3 phase electric motor was used to drive the machine via the belt and pulley transmission system. For the smooth start and stop of the machine, and the possibility of angular velocity variation of the machine helixes, an electronic driver was used for the motor.To design the machine helix, the dimensions of the examined cucumber were measured first (i.e., cucumber length and diameter); then, according to the physical and mechanical properties of the fruit, the prime mover and transmission system of the machine was designed. Finally, the fabricated machine was evaluated using some mechanization criteria.Results and DiscussionSome of the results are as follows:The total torque required to drive the machine was 3.394Nm.The electric motor power should be higher than 0.284hp; furthermore, in order to have a wider angular velocity span for the rotating shaft, a 1hp electric motor was installed on the machine.The diameter of the rotating shaft was calculated to be 15mm.The seed extracting machine could be used instead of 15 workers of the manual seed extraction method.The rate of seed extraction using the machine was 30781 kg ha-1.The efficiency of seed extraction using the machine was similar to that of the manual method.The emergence percentage of seeds obtained by the machine was similar to that of the manual method.The amount of crop calculated from the concept of economical break-even point was 7 tons.ConclusionIn this study, an apparatus for mechanized extraction of cucumber seed was designed, fabricated and evaluated. The working element of the machine is the extractor helix that is rotated via the belt and pulley transmission system, which is activated using a 1 hp, 3 phase electric motor. For smooth start and stop of the motor, as well as the possibility of angular velocity variation of the machine helix, the motor was equipped with an electronic driver. Utilizing an emergency shutdown switch, the machine can be protected from unforeseen emergency situations. After using the machine for 6 months, it was recognized that strengthening the extractor helixes was necessary. According to the results of this study, using the machine led to 15 person reduction in the labor needs of the manual cucumber seed extraction method. Moreover, the amount of crop calculated from the economical break-even point was 7.7 tons.
Design and Construction
A. Khalo ahmadi; O. R. Roustapour; A. M. Borghaee
Abstract
IntroductionProviding new solutions to control wet waste is one of the most important issues in maintaining public health. Drying will reduce the harmful effects on the environment by reducing moisture and the smell of wastes as well as easy transportation and disposal costs. The purpose of the design ...
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IntroductionProviding new solutions to control wet waste is one of the most important issues in maintaining public health. Drying will reduce the harmful effects on the environment by reducing moisture and the smell of wastes as well as easy transportation and disposal costs. The purpose of the design and development of the household dryer is to dry food waste in order to reduce its volume and prevent the spread of its pollution in the air, water, and soil. To study the drying behavior of food waste, an experimental cabinet dryer was designed, fabricated, and evaluated for drying food waste.Materials and MethodsThe dryer consisted mainly of the drying chamber, electric heater, fan, air inlet channel, mesh tray, air distribution plates, temperature sensor, and control panel. Different parts of the dryer were made of a stainless galvanized sheet. The dryer was modeled using Catia 2019 software and its various parts were designed. The heating power was calculated as 2.7 kW. A centrifugal fan with an air volume of 310 m3h-1, 2800 rpm, and 110 Pa was used to supply airflow in the dryer. In the drying process, a tray with medium and lateral air passage was fabricated and applied. Food waste was obtained from fruit and vegetable waste, homemade food, and fruit shops. And nonfood items such as glass, paper, plastics, and metals were separated from the waste and crushed with a shredder, and reduced to sizes less than 20 mm. First, the product was placed in the environment for one hour and then pressed with a mechanical press with the same pressure to eliminate part of the water. An anemometer UT363 model made in China was used to measure the air velocity. The temperature was measured and controlled by a temperature thermostat of G-sense model made in Iran. The effect of three temperatures of 50, 60, and 70 °C and three inlet velocities of 1, 1.5, and 2 m s-1 on the kinetics and intensity of drying of food waste and energy consumption of food waste with a thickness of 3 cm was investigated. Moisture ratio and drying intensity diagrams were extracted. Diffusion, activation energy, and energy consumption were determined.Results and DiscussionDrying kinetics diagrams showed that temperature had a significant effect on moisture variation of food waste during drying. Drying period decreased with increasing temperature. The slope of the drying intensity diagrams increased with the increase of the dryer temperature. Drying rate was decreased at the temperature of 70 °c and it had a steeper slope that indicates the more intensity of the drying process in this condition. The drying process of all three samples occurred in the falling rate stage. The air duct on the side and in the middle of the tray caused hot air conducted above the tray and increased energy consumption. Effective moisture diffusivity of food waste during the drying process was in the range of 3.65×10-9-4.56×10-9 (m2 s-1). The effective moisture diffusivity at temperatures of 50 °C and 60 °C was less than 70 °C. Because at the temperature of 70 °C, the membrane resistance of the cell destroyed by high heat and increased the diffusion coefficient in the material.ConclusionIncreasing temperature caused the drying period decreased and the drying occurred in the falling rate stage. Temperature and the interaction of velocity and temperature had a significant effect on the drying process. The highest drying intensity and the lowest drying time were observed at the temperature of 70 °C and a velocity of 2 m s-1. Energy consumption had the maximum value at the temperature of 70 °C and a velocity of 2 m s-1 and a minimum value at the temperature of 50 °C and a velocity of 1 ms-1. The amount of activation energy for the food waste mass at three velocities was equal to 10417.44 J mol-1.
Design and Construction
M. Hasannia Samakoush; S. R. Mousavi Seyedi; A. Mahdavian
Abstract
IntrodutionNowadays, supplying the needed food for people is one of the main global issues. Among foods, rice as the second vital crop has an important role in the world. The amount of global rice losses is about 21 percent and in Iran is reported between 16 to 30 percent that the most amount of it belongs ...
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IntrodutionNowadays, supplying the needed food for people is one of the main global issues. Among foods, rice as the second vital crop has an important role in the world. The amount of global rice losses is about 21 percent and in Iran is reported between 16 to 30 percent that the most amount of it belongs to harvest (mowers and crushers) part. The measuring device for rice picker combine losses at lab scale is a tool which could report the losses of separating and cleaning units. One of the advantages of this device is choosing maximum speed by the operator with considering the acceptable amount of seed losses. Therefore, research about detecting and decreasing this type of losses is important. In this research, only the losses of the harvesting step, especially at the end of a combine harvester machine was addressed. Different methods included piezoelectric and acoustic sensors, load cell, and FIS controller were used as the measuring device of rice picker combine seed losses. In this research, on the contrary with other studies, the slope of meshed plate and humidity of product was measured using a piezoelectric sensor at lab scale under different conditions of the rotational speed of meshed plate. Therefore, the general purpose of this research was design, construction, and evaluation of the measuring device for rice picker combine losses based on the piezoelectric sensor at lab scale to measure the seed losses in the straws at the end of the machine at rice picking.Materials and MethodsA meshed plate with the 100 × 60 cm2 dimension was one of the main parts of the measuring device of seed losses. The diameter of its meshes was 7 mm based on the rice seed size. It separates the rice seeds from straws. Separated seeds from this part were fallen on the other plate which is mounted under the meshed plate. The seeds through four separated routes were fallen on the sensors and output pulses from sensors were sent to the operator plus shown at a monitor. The used seeds at tests were selected from Fajr rice cultivar with a high yield and short height. The used piezoelectric sensor had the ability to convert imposed force and pressure to voltage and vice versa. After the seed falling on the sensor and its vibration, the piezoelectric sensor worked as a beam fixed at one end. The used Integrated Circuit (IC) was ATMEGA328, which receives the needed data through the sensor as a processing and action system. An electric motor was used to create the rotational speed of meshed plate. The LCD indicator was used for monitoring the obtained data from the test. The amount of seed losses at the end of rice picker combine machine was studied using the piezoelectric sensor with high sensitivity for detecting seeds to separate the seeds from straws. The tested sample in this research was 1 kg straw plus 52 g seed which was equal to 3 percent loss at the end of the harvest combine machine. The experimental design was a simple randomized complete design with three replications. The used treatments included the rotational speed of meshed plate at 3 levels (50, 75, and 100 rpm), the slope of meshed plate at 3 levels (25, 37, and 45 deg) plus humidity at 3 levels (12, 18, and 24 percent). Then the data analysis was done using the conducted test design. The GenStat software was used for data analysis.Results and DiscussionThe analysis of variance table showed that all treatments have a significant difference in the number of rice lost seeds at 1% probability level. The interaction between the rotational speed of meshed plate and seed humidity had a significant difference at the 1% level. On this base, the best separation of seed from straw recorded at 100 rpm and 12% humidity. The reason was the higher vibration of the meshed plate at high rotational speed and better separation of seeds at low humidity. Increasing the slope of meshed plate and humidity of seeds caused decreasing in the device efficiency. Because the motion speed of the sample on the meshed plate increased with increasing the slope of the meshed plate, a lower period was needed for separating the seeds from straws, and this separation at higher humidity was done hardly. The highest efficiency at this condition was obtained with 12% humidity and 25º slope. Increment of the rotational speed of meshed plate and decrement of meshed plate slope caused the best separation by the device. Its reason was high vibration at the high rotational speed and having enough time for separating the seeds from straws at a low slope of the meshed plate. The best angle for separating was 37º. Increment of the rotational speed of meshed plate, decrement of meshed plate slope, and sample humidity caused increasing the device efficiency. The reasons were high vibration at high rotational speed, having enough time for separating seeds from straws, and decreasing the compression at low humidity amounts. The results showed that the best device efficiency with 95.51% was obtained at 100 rpm rotational speed, humidity of 12%, and 25º slope of the meshed plate.ConclusionIn this research, a measuring device for detecting the amount of seed losses combined by straws at the end of a rice picker combine machine was designed and constructed, and then was assessed. The results of lab tests showed that increment of the rotational speed of meshed plate plus decrement of meshed plate slope and sample humidity causes an increment of device efficiency. With installation and evaluation of this device on the rice picker combine machine, the needed correction at the farm will be done and the amount of losses will be decreased.
Design and Construction
A. Rezaei; H. Masoudi; H. Zaki Dizaji; M. E. Khorasani
Abstract
Introduction The cereal combine harvester is one of the agricultural machines that works in difficult conditions and its parts are constantly under various static and dynamic loads. For the optimal design of vehicle parts, types and values of loads applied to them must be determined correctly. The purpose ...
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Introduction The cereal combine harvester is one of the agricultural machines that works in difficult conditions and its parts are constantly under various static and dynamic loads. For the optimal design of vehicle parts, types and values of loads applied to them must be determined correctly. The purpose of this study was to design and fabricate an electronic system that could instantly measure and store the amount of vertical load exerted on the rear axle of grain combine harvester in various conditions to be used in the design and optimization of the axle.Materials and Methods Main components of the designed system included a steel coupling, a disc loadcell (H2F-C2-10t ZEMIC model), an electronic board for amplifying loadcell output voltage, a data logger (AdvanTech DAQ Navi model), a 12-volt battery, and a laptop. A special steel coupling was designed in CATIA software for connecting the loadcell to the axle. The loadcell was placed between the coupling plates and then the coupling was installed on the center point of the rear axle of a JD 955 combine harvester. A standard tensile-compression testing machine (Cantam STM-150) was used to calibrate the loadcell. The relationship between the input load and the loadcell output voltage was linear and had a high coefficient of determination (R2 = 0.9991). In the static test, the vertical load exerted on the axle was recorded by the electronic system while the combine was stopped and the combine engine was in ON/OFF modes. In the dynamic test, the combine was driven in three positions including asphalt road, dirt road, and wheat field at three different forward speeds, and loads on the rear axle were recorded by the electronic system. Finally, the data obtained from the tests were analyzed as a factorial experiment in a completely randomized design with five replications in Excel and SPSS software.Results and Discussion The average static loads on the combine rear axle in ON and OFF modes were 14.908 and 14.905 kN, respectively. The results of the Student's t-test of paired samples to compare the values of axle vertical loads in two modes of static load measurement showed that there is no significant difference between the axle loads in ON and OFF mode of the engine at 1% probability level. The average vertical loads on the rear axle of the combine were equal to 15.20, 15.27, and 15.28 kN, while driving on asphalt roads at speeds of 10, 15, and 20 km h-1 respectively. These values were equal to 17.57, 17.99, and 18.15 kN, while driving on the dirt road at speeds of 2, 4, and 6 km h-1 respectively, and they were equal to 16.47, 18.01, and 17.78 kN when harvesting wheat in the field at speeds of 3, 4, and 5 km h-1 respectively. The average load applied on the axle in the turning path was more than the load applied in the straight path, which indicates load transfer to the rear axle during turning. The effect of forward speed and path type on the amount of axle load was significant at a 1% probability level, but their interaction was not significant. Therefore, the critical conditions for applying load on the rear axle of combine harvester are occurred while combine turns with high forward speed, and the design of the axle should be based on these conditions. The maximum load on the axle was obtained equal to 50 kN on the dirt road, which was due to the combine movement on a steep uphill at the end of the path.Conclusion Evaluation of the system in different conditions showed that the performance and accuracy of the system are acceptable and the data of this system can be trusted and used to measure the vertical load on the rear axle of the combine. The current rear axle of the JD955 combine harvester looks relatively safe, but at some very rugged elevations, especially steep uphills, it suffers from a lot of stress that may cause damage. So, optimizing the axle such as increasing the thickness of the triangular piece in the middle of axis and using a stronger alloy for the middle areas of the axle are recommended.
Design and Construction
O. Esmand; S. R. Mousavi Seyedi; D. Kalantari
Abstract
Introduction The use of new technology in planters is one of the most important factors in the advancement of agricultural science. In the present study, an electronic warning system has been designed and implemented to prevent large seeds from falling from the fall pipe into the ground groove. In this ...
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Introduction The use of new technology in planters is one of the most important factors in the advancement of agricultural science. In the present study, an electronic warning system has been designed and implemented to prevent large seeds from falling from the fall pipe into the ground groove. In this study, three types of corn, bean and soybean seeds have been used, using two laser and microwave sensors. Viewing and comparison of the two sensors and their performance in two conditions of medium and high sensitivity in both laboratory and field conditions were conducted. In this case, the differences between the two sensors in different sensitivities have been evaluated and compared. The performance of the sensors in seed count has also been studied and compared. According to the results obtained in both cases, the sensors performance was acceptable, and especially in the maximum sensitivity of the sensors, they were able to handle well the clogs created in different situations (clogging down or above the fall pipe or emptying the seed tank). Detect and alert in a timely manner. Also, the count of seeds in all three seed types was recorded with high accuracy compared to the actual number. Materials and Methods Three types of coarse seeds (corn, beans and soybeans) as well as two types of sensors (laser and microwave) with two levels of medium sensitivity and high sensitivity were used for the experiments. Laser sensors are one of the most precise instrumentation and industrial automation tools that use laser light to detect objects or even precise distances. The function of the microwave sensor is that the high frequency waves are transmitted when the power supply is connected. These waves are reflected back to the module receiver if they hit objects. The open waves in the module are multiplied by the frequency of transmission by the mixer and a low-output (IF) signal is generated. The output frequency is equal to the difference between the frequency of the transmitted and reflected waves caused by the Doppler effect. Based on this frequency, the presence of a moving object and its speed are detected. Experiments were carried out at both laboratory and field levels and in both moderate and high sensitivity modes using variable resistance mounted on the controller. The equivalent distance for each seed test is 100 meters, so twice for each seed in the laboratory and field level for each of the laser and microwave sensors in both high and medium sensitivity modes. In this system, in case of falling pipe clogging due to seed accumulation or mud under the falling pipe or other factors, an alert system (warning beep), along with the corresponding LED light, indicates a problem in the seed fall system and the operator alerts paying attention to the LED light (green or red) will detect the problem. Results and Discussion The results indicated that by installing a variable resistance inside the circuit, different sensors can be created in the sensors. Increasing the sensitivity of the sensor as much as possible can cause higher the efficiency of the sensor. In the two cases of medium and high resistance, sensors work with medium and high sensitivity. It works since both modes have been tested and the results have been satisfactory. The accuracy of counting and seed detection accuracy between two laser sensors and microwave sensors in two medium and high sensitivity modes were calculated and evaluated. The experiments in the laboratory showed that the difference in the number of seed count by laser sensor compared to the actual number in maize seed at medium and high sensitivity were 87.4% and 94.3%, respectively, in bean seeds 89.1% and 94.2%, respectively. And in soybean seed were 89.4% and 92.3%, respectively. Conclusion The developed embedded system can successfully check and announce the instantaneous state of three types of grain tested (corn, beans and soybeans) in the seed delivery tube of a hand single-row planter with visual cues (on or off LED lights) and audible signals (on or off the alarm), whenever there is a grain flow or no grain flow. Likewise, the developed system can show the blockage at the end of the seed delivery tube with visual indications of the green and red lights on or off and the alarm sound described in detail. These warnings are indications of a fall pipe failure or lack of grain flow in the grain measuring mechanism toward the opening groove and then into the ground. This type of detection alerts the operator in a timely manner by monitoring the status of the grains in the measuring system and ensuring that the grains are located in the ground.
Design and Construction
P. Pashaee; H. R. Ghasemzadeh; H. Behfar
Abstract
Introduction According to reports on trends in the agricultural industry, demand for more precise and affordable machinery is rising and precision farming methods used by farmers are expanding. Damping vibration of the boom sprayer is one of the challenges for researchers when crossing the surface roughness. ...
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Introduction According to reports on trends in the agricultural industry, demand for more precise and affordable machinery is rising and precision farming methods used by farmers are expanding. Damping vibration of the boom sprayer is one of the challenges for researchers when crossing the surface roughness. The lack of uniformity of the nozzle spray pattern and the reduction of the precision and quality is the result of an uncontrolled vibration of the boom sprayer. So far, many efforts have been made to decrease the vibration of the long sprayer boom. Using active and passive methods, researchers have achieved great success in reducing the spray boom vibration. Many of these methods are based on the use of external force as a controlling force. Expensive equipment, the use of tractor hydraulic power, and high energy costs are the main disadvantages of these methods. In the present work, a new system called "variable support" was designed and built. The boom rests on a round bar at its midpoint; as the boom tends to oscillate, a minute amount of rotation of the bar activated by a servomotor in an appropriate direction, alters the position of the resting point of the boom on the supporting bar, bringing the boom back to its initial balanced position as a result.Materials and Methods To carry out experiments, the universal tractor U650 and a mounted tractor sprayer model tms500 with 8 m boom and a 500-liter tank, was used in this research by making changes to the design of the simple tractor sprayer a new active sprayer designed and built with intelligent online balancing system that in addition to balancing the boom angle, it reduced the fluctuations that occur during work. Electronic control was used to control the position of the boom. The microcontroller programming codes were developed and uploaded in the microprocessor to execute instantaneous commands to the mounted activator due to the need for boom positional data for analyzing experiments, a data logger was also designed in conjunction with the controller circuit and the algorithm was loaded after coding with C++. To compare the new sprayer with the conventional, a field test was conducted. Tests were carried out according to manufacturer's instructions at three-speed levels of 3 (low), 5 (medium), and 8 km h-1 (high), with three bumps heights of 10, 15, and 20 cm with three replications. For the acquisition of vertical acceleration as well as axial rotation data in the conventional sprayer, a data logger with an accelerometer and gyroscope was used. The data logging rate and the accuracy of the accelerometer and gyroscope measurement were set to 50 Hz, 0.1 m s-2 and 0.1°, respectively.Results and Discussion To compare the behavior of the active and the conventional spray booms in terms of vibrations, the univariate analysis was used. The results showed that there was a significant difference between the performances of two sprayers at 5% probability level with the sig. number of 0.000.To compare the behavior of the active and the conventional spray booms in terms of axial rotation, also the Univariate analysis was used. The results showed that there was significant difference between the performances of two sprayers at 5% probability level with the sig. number of 0.000. Also, comparing the marginal mean values of the data obtained from the data logger showed that the active boom compared with the conventional boom had less axial rotation and less vertical acceleration.Conclusion Results of experiments showed that the new sprayer with variable support system, relative to the conventional sprayer in terms of controlling boom acceleration and the angular balance of the boom with a significant difference had relative superiority and can be considered as an appropriate alternative to increase the accuracy of spraying, although more research on large scale booms are necessary before coming to final conclusion.
Design and Construction
V. Neisari fam; R. Tabatabaei koloor; A. Motevali
Abstract
IntroductionAlmonds (Prunus amygdalus) belongs to the family of Rosaceae and the subspecies of Pronoideae. Its kernel contains a lot of energy, amino acids, sugars and mineral elements. Iran is ranked fifth in terms of producing almonds after United States, Australia, Spain, and Morocco, but at the same ...
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IntroductionAlmonds (Prunus amygdalus) belongs to the family of Rosaceae and the subspecies of Pronoideae. Its kernel contains a lot of energy, amino acids, sugars and mineral elements. Iran is ranked fifth in terms of producing almonds after United States, Australia, Spain, and Morocco, but at the same time, Iran's position is not very suitable in the world export market. The processing of this product involves three stages of shell breaking, kernel separation, and packaging. One of the important methods of separation of the kernel from the wooden crust is the use of pneumatic separation and this method can be used to grade, clean, and separate the seeds of different materials.Materials and MethodsAlmond samples of the Shokofeh variety (A.H.3) were obtained from Maragheh gardens in East Azarbaijan province. The moisture content of the shell, the kernel, and mixture of them was determined using the oven drying method. Also, some physical and mechanical properties were measured. In order to design the almond separator system, it is important to determine aerodynamic properties. The most important aerodynamic properties such as terminal velocity and drag force were determined. The first step in designing and manufacturing a device is to select the cross-sectional shape and dimension. The cross-section of the machine is selected based on parameters such as simplicity and construction costs. With the assumption of a machine with a separation capacity of 2 kg (mixed product) per minute, the length and the width of the machine were obtained to be 18 cm and 15 cm. Using the terminal velocity and dimensional data, the blower distance to the outlet, the tunnel length, the power and flow rate of the blower were calculated and then the design and construction were done. To evaluate the separation and evaluation of the apparatus, parameters such as blower speed, shell size, and moisture content of the mixture were investigated for each parameter at three levels. Airflow rates of the wind tunnel were 3, 5, and 7 m s-1, moisture content (7%, 13%, and 19%), shell size in three groups: small, medium, and large.Results and DiscussionThe average geometric properties including length, width, thickness, geometric mean diameter, and spherical coefficient for almonds were 20.64, 13.25, 7.4, 12.64 mm, and 0.612, respectively, as well as properties for large shells (25.17, 16.5, 11.15, 16.66 mm, and 0.66), for average size (17.36, 13.5, 6.4, 11.44 mm, and 0.65) and fine size (13, 9.9, 3.5, 7.66 mm, and 0.59), respectively. The mechanical properties of the samples (shell and almond kernel) were measured at three levels of moisture content of 7%, 13%, and 19%. The results showed that by increasing the moisture content, the fracture force for both shell and kernel increases. Almond shell had the highest angle of rotation at all levels of moisture. This was due to its heterogeneous shape, broken edges and rough surface. On the other hand, almonds had the lowest degree of rotation, due to the greater weight of the kernel and the more homogeneous and spherical shape than the shell. The results obtained from measuring the terminal velocity of the samples selected from the kernel and shell in terms of their weight indicated that the velocity limit for the almonds was 10.2-12.2 m s-1 and for the shell, the range was 1.8-6 m s-1. The variance analysis of the effect of particle size, velocity, and moisture parameters on the level of separation of shell in almond mixture showed that all major effects and interactions of factors were significant at 1% probability level. Particle size and moisture content did not affect the separation rate at 7 m s-1. With decreasing velocity, the separation rate in the particle size was reduced, which was due to the higher speed of the separation rate. At low velocity, the best separation was related to the fine particle size, which was due to the harmonization of the fine particle velocity and the separation rate.ConclusionPneumatic separation of almond kernel and shell was affected by air velocity, particle size and moisture content. As the flow rate increases, the amount of shell separation from the kernel increases. Particle size and moisture content did not affect the separation rate at 7 m s-1. The results at medium moisture content indicated that in addition to the acceptable separation level (relative to other moisture levels) at this level (13%), the harvesting time of this product can be managed and the use of additional energy in the processing of this product is prevented.
Design and Construction
J. Soleimani; M. H. Kianmehr; S. R. Hassan Beigi Bidgoli; S. M. Shariatmadari; K. Rezapoor
Abstract
Introduction The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet manure is the profound method for decreasing the manure volume which reduces the cost ...
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Introduction The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet manure is the profound method for decreasing the manure volume which reduces the cost of handling and storage. Besides, the particle size is one of the important factors in the pellet production. Ball mills, vibratory mills, hammer mills, knife mills, two roll mills, colloid mills, attrition mills, or extruders can be used for size reduction of biomass. Specific energy consumption for size reduction of biomass highly depends on moisture content, bulk and particle densities, feed rate of the material, particle size distribution (initial/final particle size) and machine variables. The present study is conducted for wet cattle manure size reduction machine. Furthermore, the relationship between moisture content (35, 40 and 45 %w.b) and drum of special size reduction machine in rotational speed (150, 200 and 250 rpm) considering geometric mean diameter of particle and size distribution of wet cattle manure were investigated. A factorial experiment under randomized complete design method was employed with three replications. Materials and Methods The main parts of machine include drum, concave, spring and adjusting screw. The main function of this thresher machine is to combine crushing and cutting in order to conduct the size reduction methods, i.e., to apply compressive and shear forces to the cattle manure particles. The drum is also equipped with several rows of sharp-edged milling segments. The spring constants were determined by evaluating the slope of the force vs. deflection curves. The rotational speed of drum was changed in the range of 100-700 rpm during these experiments. In the test of the machine physical properties of grinds such as geometric mean diameter of grind particles and particle size distribution were determined. One kg of cattle manure was grinded in each test and the particle size distribution of grinded cattle manure was determined according to ASAE standard S319.3. The moisture content of cattle manure was obtained according to ASAE standard S358.3. Results and Discussion The initial and final particle size of the materials are 20 millimeters and less than 5 millimeters, respectively and the angle of nip is 30 degrees (according to the installation space limitations), the diameter of the drum is 310 millimeters. The spring constant was equal to 24.371 N mm-1 and on the basis of the experiments a drum speed in the range of 150–250 rpm is considered to be optimal settings for the milling for cattle manure disintegration. The results of Table 4 show that for wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P > 0.05; Skewness = 0.095; Kurtosis = -1.72), in grinds that would potentially produce better compacts. The geometric mean particle size and standard deviation for each test are shown in Table 2. According to Table 2, the lowest geometric mean of particle size is related to rotational speed of 200 rpm and a moisture content of 45% (w.b), and the highest at rotational speed of 250 rpm and a moisture content of 45% (w.b) can be observed. Conclusion The use of cattle manure of thresher machine reduces the specific energy consumption of cattle manure by 92% compared to the conventional method (using drying and hammer mill) in the pellet production. The lowest geometric mean diameter of wet cattle manure was 1.02 millimeter for drum rotational speed of 200 rpm at 45% (w.b) moisture content and the highest was 1.38 at rotational speed of 250 rpm and a moisture content of 45% (w.b%). The best particle size distribution was observed for milling of wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P> 0.05; Skewness = 0.095; Kurtosis = -1.72)
Design and Construction
S. Rezaei; M. Dowlati; R. Abbaszadeh
Abstract
Non-chemical treatments are an approach for improving seed germination. In order to evaluate the effects of the magnetic field application on onion seed germination and seedling growth indices, a quadrupole magnetic field system was designed and fabricated. It was also compared with a dipole magnetic ...
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Non-chemical treatments are an approach for improving seed germination. In order to evaluate the effects of the magnetic field application on onion seed germination and seedling growth indices, a quadrupole magnetic field system was designed and fabricated. It was also compared with a dipole magnetic field system. In the quadrupole system, each coil consisted of three layers and the cores were moved inside the coils. These arrangements make it possible to change the magnetic field intensity in addition to input current setting. The experiments were conducted based on factors including the type of system (bipolar and quadrupole), magnetic flux density (75, 150, 300 and 600 μT) and duration of the field application (15, 30, 60 and 120 min). Germination percentage, germination rate, mean germination time, seedling vigor index, shoot length, root length, fresh weight of shoot and root, fresh weight of seedling, dry weight of shoot and root were measured. The results showed significant effects on seed germination and seedling growth of onion. In most germination characteristics, the quadrupole system had a better impact than the bipolar system. For many traits (except for weights), the increase in field intensity degraded the traits. Quadrupole system that applied the magnetic field of 600 μT for 15 minutes, yielded 63% increase in the total seedling weight. Most of the germination traits were not affected by exposure time. Further investigations are required for shorter exposure times compared to used durations in this study.
Design and Construction
H. Dehghan-Hesar; D. Kalantari
Abstract
Introduction Optimizing the energy consumption in mechanized agriculture is becoming more important due to the limited energy sources in the world. In this regard, optimization of the cutting blades is presented in this study by modifying the geometric form of the blade to reduce the forage cutting energy. ...
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Introduction Optimizing the energy consumption in mechanized agriculture is becoming more important due to the limited energy sources in the world. In this regard, optimization of the cutting blades is presented in this study by modifying the geometric form of the blade to reduce the forage cutting energy. Hence, two new blades, inspired by the geometric profiles of front claws of mole crickets and teeth of grasshoppers were designed and built using the biomimetic method (the method for transferring biological solutions to the engineering ones). Finally, the new biomimetic blades were tested and compared with two other conventional blades (flat and bent blades) by cutting 8 different types of crops and weeds. Materials and Methods The main idea of building one of the blades was inspired by the geometric forms of mole crickets' scissors-like front legs and lower teeth of grasshoppers. Therefore, five adult mole crickets and five grasshoppers were collected from a farm in Kalat-e Naderi, Khorasan Razavi Province. In the next step, different images were captured from the front leg of mole cricket and tooth of grasshopper using the stereomicroscope (Nikon, SMZ-U, Japan). In the next step, the images were transferred to the image analysis software (Image J) and the boundary lines of images were selected. Then, the selected boundary lines were imported to SolidWorks software and the points on the selected curve were extracted. The obtained points were drawn in Matlab software and several fitting curves for the points were examined, e.g., Fourier function, Gaussian function, and polynomial function. According to the obtained results, the Gaussian profile was selected to design the blade with the highest correlation coefficient (R2=0.99), see Fig. 1d. To design the desired blade, a section of the Gaussian curve between points A and B were used. Finally, the biomimetic blade of the mole cricket and grasshopper were drawn in SolidWorks software (Fig. 1e). After designing the blades in the SolidWorks software, the biomimetic blades were built by a CNC machine. Results and Discussion In all the treatments, a significant difference was observed between the biomimetic blades and the conventional flat and bent blades according to the results of Tukey's test at the level of 5%. The obtained results showed that there was no significant difference between the mole cricket and grasshopper blades at the level of 5% for cutting. According to the results obtained in this study, there was a significant difference at the level of 5% between the grasshopper and flat blades for cutting alfalfa, clover, amaranth, orach, and poaceae; as well as between the grasshopper and bent blades for cutting alfalfa, clover, nutsedge, and amaranth, also between mole cricket and flat blades for cutting alfalfa, clover, purslane, amaranth, orach, paddy, and poaceae and finally between mole cricket and flat blades in cutting alfalfa, clover, nutsedge, amaranthus, and paddy. In this regard, no significant difference at the level of 5% was observed between the flat and bent blades for all cutting treatment. The batches containing 6 stems were used for cutting the soft stems with low shear stress and the batches containing 4 stems were used for cutting thick stems with high shear stress. Conclusion The results obtained in this study indicated that the geometrical form of the blade has a significant influence on the amount of required shear energy. The mole cricket biomimetic blade reduced the cutting energy compared to the flat blade by 23.37% to 52.51% (with the mean of 39.11%) and compared to the bent blade by 10.46% to 52.46% (with the mean of 32.8%). The grasshopper biomimetic blade also reduced the cutting energy compared to the flat blade by 15.78% to 53.82% (with the mean of 33.59%) and compared to the bent blade by 2% to 46.29% (with the mean of 27.87%). According to the results of this study, the mole cricket biomimetic blade showed better performance in comparison with the grasshopper biomimetic blade for cutting the plants and as a final result could be recommended to build the plant cutting blades.
Design and Construction
H. Biabi; S. Abdanan Mehdizadeh; M. Nadafzadeh; M. Salehi Salmi
Abstract
Introduction Leaf color is usually used as a guide for assessments of nutrient status and plant health. Most of the existing methods that examined relationships between chlorophyll status and carotenoid of leaf color were developed for particular species. Different methods have been developed to measure ...
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Introduction Leaf color is usually used as a guide for assessments of nutrient status and plant health. Most of the existing methods that examined relationships between chlorophyll status and carotenoid of leaf color were developed for particular species. Different methods have been developed to measure chlorophyll status and carotenoid. However, the high cost and difficulty to use have restricted their application, whereas the handheld chlorophyll meters such as the SPAD has become popular in the last decade for non-destructive measurement of chlorophyll content. SPAD meter readings have found to be related to the plant’s nutrition status, seed protein content, types of nodulation, and photosynthetic rates of leaves. Digital color (RGB) image analysis, another nondestructive technique is becoming increasingly popular with its potential in phenotyping various parameters of plant health status. The development of low-cost digital cameras that use charged-couple device (CCD) arrays to capture images offers an advantage of low-cost real-time monitoring process over optical sensor based SPAD meter. Gupta et al. (2012) estimated chlorophyll content, using simple leaf digital analysis procedure in parallel to a SPAD chlorophyll content meter. The chlorophyll content as determined by the SPAD meter was significantly correlated to the RGB values of leaf image analysis (RMSE = 3.97). The aim of this research is developing a new inexpensive, hand-held and easy-to-use technique for detection of chlorophyll and carotenoid content in plants based on leaf color. This method provides rapid analysis and data storage at minimal cost and does not require any technical or laboratory skills. Materials and Methods Sample collection In this research, 15 leaves were randomly selected from six types of plants (Shoeblackplant, Vitex, Spiderwort, Sacred fig, Vine and Lotus). Afterwards, the chlorophyll content of the leaf was measured in 3 different ways: 1) using a SPAD instrument; 2) using machine vision system (non-destructive method), and 3) laboratory test using a spectrophotometer. Chlorophyll and carotenoid content The chlorophyll content of the leaf was measured and recorded using SPAD chlorophyll meter (Hansatech, model CL-01, Japan) and spectrometer as explained by Dey et al. (2016). Furthermore, to measure the carotenoid content method described by Gitelson et al. (2006) was utilized. Image processing For estimation of chlorophyll using the image processing algorithm, sample images were taken using CCD (CASIO, model Exilim EX-ZR700, Japan) and transferred to the computer. The camera was mounted perpendicular to the horizontal plane at a fixed distance of 25 cm from the samples. In a consequence histogram of leaf, images were equalized and the average of each color channels from RGB, Lab, HSV, and I1I2I3 were extracted using Matlab 2016. Decision tree regression (DTR) algorithm To develop a regression model to predict chlorophyll and carotenoid content, two decision tree were constructed. The average of each color channels from RGB, Lab, HSV, and I1I2I3 become the predictor variables or feature vector and the real known chlorophyll and carotenoid content become the target variable or the target vector of each regression tree. To develop the regression models, dataset (90 observations) was split into training (60 observations) and test (30 observations) data. Results and Discussion According to the obtained results, a high correlation of 0.92 for chlorophyll and 0.85 for carotenoid was achieved, respectively, between the image processing method and the values measured by the spectrometer. Therefore, it can be said that the proposed image processing method has a desirable and acceptable performance for prediction of both chlorophyll content and carotenoid. The review points out a need for fast and precise leaf chlorophyll measurement technique. With this in mind, Dey et al. (2016) used image processing techniques to measure chlorophyll content. For the purpose of analysis of the proposed model, the model outcome was compared with the LEAF+ chlorophyll meter reading. Regression analysis proofed that there was a strong correlation between the proposed image processing technique and chlorophyll meter reading. Thus, it appears that the proposed image processing technique of leaf chlorophyll measurement will be a good alternative for measuring leaf chlorophyll rapidly and with ease. Conclusion In this research, collections of images from six divers plants (Shoeblackplant, Vitex, Spiderwort, Sacred fig, Vine and Lotus) were analyzed to predict chlorophyll and carotenoid content at different color spaces (RGB, Lab, HSV, and I1I2I3). Based on the results, it was shown that there were high correlations of 0.92 for chlorophyll content as well as 0.85 for carotenoid between the image processing method and the values measured by the spectrometer. Therefore, in general, it can be concluded that the proposed image processing method has a desirable and acceptable performance for prediction of chlorophyll content as well carotenoid.
Design and Construction
A. Rezahosseini; K. Jafari Naeimi; H. Mortezapour
Abstract
Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran ...
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Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran in 2015. Development of cabbage harvesting industry is necessary, because of the large cultivation area and the short available harvesting time. So far, a few studies have been done on cabbage mechanized harvesting in Iran. The harvesting machines can reduce harvesting time to one-eighth in comparison with manual harvesting. Design and manufacturing of a harvester unit suitable for small cabbage farms in Iran were conducted in the present study. So the paper was aimed to investigate the performance of the harvester at the different forward velocities, attack angles and distances between the plants. Materials and Methods The proposed machine consists of two major units; the soil looser and the unit for pulling out, crops from the soil. In this machine, the blades loose the soil around the cabbage root after penetrating into the soil. Next, cabbage is pulled out from the soil by puller belts. The belts move contrary to forward speed direction and take crop to the backward of the machine. Mechanical and physical properties of the cabbages should be measured, because the harvester is directly in touch with the crop. These properties are firstly measured and then selection of the different components and machine manufacturing are done. Two narrow legs (tillage tools) equipped with one-side blade with attack angles of 20 and 25 degrees are used for losing the soil around the cabbage’s root. The force exerted on the blade was 5.47 kN. Finally, the harvesting force is estimated to be 164.8 N by using mechanical and physical properties of the cabbages. Experiments were conducted at the different forward velocity levels (2, 3.5 and 5 km h-1), attack angle of the blades at three levels (20, 25 and 30 degree) and the distance between the crops in two levels (40 and 60 cm) in a completely randomized design with three replications. Results and Discussion The analysis of variance of the effect of different parameters on the harvested crop numbers showed, that the effects of forward velocity and attack angle on the number of harvested crops were significant in 5 percent probability. But distance between crops did not have significant effect on the number of harvested crops. Also the effects of interaction between forward velocity and attack angle, forward velocity and distance between crops, attack angle and distance between crops on the number of harvested crops were significant in 5 percent probability. According to the results, the number of harvested crops and machine performance were decreased by increasing forward velocity. Moreover, designed machine had the best performance (80 percent) at an attack angle of 25 degrees and forward velocity of 2 km h-1. Conclusion The results showed, with increasing the forward speed from 2 to 5 km h-1 the harvest success decreased by 20 to 25 percent. Also, the harvesting quality did not change at the different distances between the plants. The highest machine capacity was more than 5300 plants per hour, which was observed at the forward velocity of 3.5 km h-1 and the attack angle of 25 degrees.
Design and Construction
S. Hasantabar; S. R. Mousavi Seyedi; D. Kalantari
Abstract
Introduction Nowadays, due to growth and development of the husbandry and its worthiness in providing human basic needs, affecting parameters such as costs, efficiency and fuel consumption is significantly important. So, increasing the efficiency of threshing machine could lead us to huge savings in ...
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Introduction Nowadays, due to growth and development of the husbandry and its worthiness in providing human basic needs, affecting parameters such as costs, efficiency and fuel consumption is significantly important. So, increasing the efficiency of threshing machine could lead us to huge savings in energy. However using the conventional drums and concaves have some problems such as damaging seeds due to impact, complicated manufacturing technology and spending a lot of energy in separating process. Therefore in order to overcome above mentioned problems especially energy consumption, a new seed pod husker based on rubbing was designed, fabricated and tested in this research. Materials and Methods Practical tests of this device were carried out on soybean which was harvested in a farm of Babolsar city. The experimental design was simple randomized complete design with three replications. The rotational speed of rollers and distance between rollers varied in three levels of 110, 170, and 210 rpm and 7, 8, and 9 mm for soybean. The measured parameters consisted of efficiency, separation and loss. For designing the seed pod husker, the required electric motor power and the torque for separating seeds from its pods were calculated. After reviewing the physical and mechanical characteristic of some seed pod crops specially, soybean, a seed pod husker was designed in SOLIDWORKS 2013 software. In order to facilitate seeds separation from the pod, it was preferred to use the right-round and left-round Archimedes screw on the rollers. According to the preliminary evaluations, it was considered to use a speed range of 110 to 210 rpm; it was because of that the speed lower than 110 rpm was not able to open pods and the speed higher than 210 rpm caused hyper movements of pods. Analysis of variance (ANOVA) and mean comparisons and interaction between the parameters were performed using the SPSS 22 software. Results and Discussion The results indicated that the rollers were acceptable and sticking of pods were not seen. Results indicated that the efficiency of this device was increased with increasing the rotational speed and then was decreased. Increasing the rotational speed was led to increase separation. It is because of this fact that the performance of the husker’s component will be more powerful and crops suffer bigger impacts. The chart of device loss had a relatively upward slope. It could be due to a tougher collision between the seeds and the rollers. Increasing the roller distance, first decreased the efficiency of soybean and then increased that. The results indicated that separation efficiency decreased by increasing the distance. The reason for that was due to unavailable necessary force to separate the seed and pod. As the roller distance increased, the total losses of the device also increased. The reason for this was likely increasing in the movement of the seeds. Conclusion The results of practical tests and qualitative observations showed that the device had sufficient resistance against the maximum torque produced by the crop. Influence of rotational speed of rollers and rollers clearance on the efficiency, separation and loss were significant for new fabricated seed pod husker (p < 0.01). The capacity of the machine for soybean was 28.506 (kg hr-1). To achieve maximum efficiency, maximum separation and minimum loss for soybean, authors suggest using (9mm-170rpm), (7mm-210rpm) and (9mm-110rpm) compounds, respectively. Eventually, it is suggested to evaluate this machine for other seed pod crops and for other parameters such as germination percentage, electric conductivity and ergonomic issues such as noise and machine vibration. Of course, it is recommended to survey the impact of length of husking roller, shaft rotation method and thread types on measurement parameters.
Agricultural waste management
M. A. Ebrahimi-Nik; A. Rohani
Abstract
Introduction More than 40 percent of the world population is now dependent on biomass as their main source of energy for cooking. In Iran, the lack of access roads and inefficient transportation structure have made some societies to adopt biomass as the main energy source for cooking. In such societies, ...
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Introduction More than 40 percent of the world population is now dependent on biomass as their main source of energy for cooking. In Iran, the lack of access roads and inefficient transportation structure have made some societies to adopt biomass as the main energy source for cooking. In such societies, inefficient traditional three-wall cook stoves (TCS) are the sole method of cooking with biomass, which corresponds to the large fuel consumption and smoke emission. Biomass gasifier cook stoves have been on the focus of many studies as a solution for such regions. In these stoves, biomass is pyrolized with the supply of primary air. The pyrolysis vapors are then mixed with secondary air in a combustion chamber where a clean flame forms. In this study, a biomass cook stove was manufactured and its performance was evaluated feeding with three kind of biomass wastes (e.g. almond shell, wood chips, and corn cob). Materials and Methods A natural draft semi-gasifier stove was manufactured based on the stove proposed by (Anderson et al., 2007). It had two concentric metal cylinders with two sets of primary and secondary air inlet holes. It had 305 mm height and 200 mm diameter. The stove was fed by wood chips, almond shell, and corn cob. Thermal performance of the stove was evaluated based on the standard for water boiling test. It consisted of three phases of cold start, hot start, and simmering. Time to boil, burning rate, and fire power was measured in minute. A “K” type thermocouple was used to measure the water temperature. Emission of carbon monoxide from the stove was measured in three situations (e.g. open area, kitchen without hood, and kitchen under hood) using CO meter (CO110, Thaiwan). Results and Discussion Neither particulate matter nor smoke was visually observed during the stove operation except at the final seconds when the stove was going to run out of fuel. The flame color was yellow and partly blue. The average time to boil was 15 min; not significantly longer than that of the LPG stove (13 min). Time to boil in hot phase was almost the same for all fuels which is not in line with the studies reported by (Kshirsagar and Kalamkar, 2014; Ochieng et al., 2013; Parmigiani et al., 2014). This is probably due to the stove body material. In fact, the hot phase test, aims to show the effect of the stove body temperature on the performance. In contrast with the most of the stoves, the one was used in the present study was made of a thin (0.3 mm) iron sheet which has a high heat transfer and low heat capacity. This results in a rapid increase in the stove body temperature up to its highest possible. The longest flaming duration (51 min) was observed by 350 g almond shell. Thermal efficiency on the other hand, was different in using different biomass fuels. The average thermal efficiency of 40.8 was achieved by the stove which is almost three times of open fire. The results from emission test showed that the average of carbon monoxide surrounding the operator in the case of open area, kitchen without hood, kitchen under hood, and traditional open fire were 4.7, 7.5, 5.2, and 430 ppm, respectively. Conclusion The amount of carbon monoxide emitted to the room is in accordance with the US National ambient air quality standards (NAAQS) hence, compared with traditional methods of cooking in deprived regions, the stove burns cleaner with higher efficiency. In order to prohibit respiratory decreases in housekeeping women, this stove could be disseminated in some deprived regions of Iran.
