Precision Farming
B. Besharati; A. Jafari; H. Mousazadeh; H. Navid
Abstract
IntroductionVarious methods have been performed to control weeds in the world and the use of herbicides is one of them, but public concerns about human health have changed interest in alternative methods. Thermal methods based on flame-weeder, hot air, steam, and hot water have the potential to control ...
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IntroductionVarious methods have been performed to control weeds in the world and the use of herbicides is one of them, but public concerns about human health have changed interest in alternative methods. Thermal methods based on flame-weeder, hot air, steam, and hot water have the potential to control weeds, but due to the high cost are not economical. Electromagnetic waves transfer energy into weeds and finally destroy them. The effect of radiation on plant mutation, high consumption of energy, and human health are problems for this approach. Unlike other methods, electrical energy is an ideal and non-chemical method for weeds. This method applies high voltage to weeds, their roots, and soil so that electric currents pass through them, and the vaporization of the liquid content of weeds kills the weeds. To increase the severity of damage to weeds, the development of a feedback mechanism is required. The ultrasonic sensor measuring physical parameters like plant height is a simple method. Some complex sensing systems include optical sensors such as infrared, and machine vision that require high-speed processors and expensive equipment. In this project, as a simple method, the monitoring of the electrical current passing through weeds was used for developing the feedback mechanism and increasing electric damage to weeds.Materials and MethodsIn this study, the system consisted of a high-voltage device that generated a 15 kV AC voltage to kill weeds, as well as a feedback mechanism that included a sensor to measure the electric current on the input of the weed killer and identify the presence of weeds and their annihilation. All parts were installed on a robotic platform, and an application on a laptop was connected to it via an access point for navigation and data reception. The system was tested in a greenhouse lab with various weeds. Initially, a test was performed to investigate the effect of high voltage on the weeds and establish relationships between the electric currents passing through weeds and their presence (before and after annihilation). During the test, the system was guided along a path and applied high voltage to kill the weeds. The feedback mechanism was then calibrated based on the extracted data on electric current relations. This allowed the system to detect weeds and their annihilation, enabling it to move to the next target once a weed had been eliminated. After calibration, a comparative test was conducted to evaluate the weed-killing efficiency of the two methods (with and without the feedback mechanism), and the results were analyzed using a t-test with p ≤ 0.01.Results and DiscussionThe observations indicated that the input electric current on the weed killer was dependent on the electric current passing through weeds. When the high-voltage electrode touched a weed, the electric current passed through it increased, and simultaneously, the high electrical energy destroyed the weed. After the removal of the weed, the electric current rapidly decreased. The average energy consumption per weed plant was estimated to be 250 joules, which can be compared with other methods. The final test comparing the use and non-use of the feedback mechanism revealed significant differences (P < 0.01) between the results obtained with and without the mechanism, demonstrating that the feedback mechanism increased the efficiency of weed annihilation. The sensing system used in the developed feedback mechanism is a simple method that is affected by the electrical resistivity of weeds. As such, it did not mistakenly detect other objects as weeds, unlike an ultrasonic mechanism. Based on these results, monitoring the electrical current passing through weeds proved to be a suitable method for developing a feedback mechanism for the weed killer to identify the presence of weeds and their annihilation.ConclusionThe use of high voltage as a non-chemical and alternative method for weed control has shown promising results. The study revealed that measuring the electric current applied to the weed killer was an effective and straightforward approach to developing a feedback mechanism. This mechanism aids in identifying the presence of weeds and ensuring their elimination by intensifying the damage inflicted on them through the application of high electrical energy. To further enhance the efficiency and speed of weed control, future research should consider integrating an automatic guidance mechanism with the weed killer.
Post-harvest technologies
A. Ramezani Boukat; H. Navid; M. J. Musevi Niya; S. Ranjbar
Abstract
Introduction Transportation of fresh fruit and vegetables is complicated because it can be affected by various factors. Truck vibration is one of the most prevalent causes of mechanical damage to fresh fruit during transportation. Poor driving performance, road features, package features, truck features, ...
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Introduction Transportation of fresh fruit and vegetables is complicated because it can be affected by various factors. Truck vibration is one of the most prevalent causes of mechanical damage to fresh fruit during transportation. Poor driving performance, road features, package features, truck features, package location, and fruit features are the main factors that affect truck vibration. After the harvest, the crop's quality can be maintained and cannot be improved. Thus, the globalization of fresh produce trade needs better long-distance transportation systems to deliver high-quality products to the consumer. Fruit packaging is an essential factor in reducing the mechanical damages caused by transportation. A wide-ranging of distribution environments could affect designing packages. Accurate information about the traffic and transportation status of any region helps packaging designers to produce a more precise simulation of the existing conditions. Thus, this research was conducted to analyze the vibration levels for truck transport on highway roads using multi-sensor-based computing on packaged fruit in Iran.Materials and Methods Towards this goal, a wireless sensor network (WSN) made of three sensor nodes with tri-axial accelerometers was designed to measure the vibration levels of a truck equipped with leaf-spring suspension on highway roads. This WSN solution enabled the sensors to be easily mounted at different locations and provided real-time data monitoring. A GPS receiver and a laptop were used to determine the location of the truck, and data analysis, receptively. To analyze the vibration data a, power spectral density function (PSD) levels were applied. A PSD function shows the strength of the variations (energy) as a function of frequency. Broadly, it shows at which frequencies variations are strong and weak. The vibration levels measurement was carried out on three trucks with leaf-spring suspension. The three selected routes represent different roads type in Iran. The reason for sampling the data acquired in the long route was to obtain information from different geographical locations on the country's roads.Results and Discussion The acquired data can be used in laboratory vibration tests if it is independent of the fruit type. Because the acceleration of the truck bed, unlike the one in top rows, does not depend on the fruit type and the acceleration at the end of the truck is higher than at the front, the current study focused on the vibration at the end of the truck bed. Compared to the ASTM 4728 standard, the PSD levels of the truck on highway roads were higher from 1 to 35 Hz and lower from 35 to 200 Hz. The average RMSG values calculated for lateral, longitudinal and vertical directions of heavy trucks were 0.406, 0.236, and 0.654 G, respectively. For trucks with spring suspension, the highest PSD values occurred at frequencies below 6 Hz, and the frequency range of 3-4 Hz was determined as the dominant frequency. Comparing the average RMSG (0.654 G) found with the ones mentioned in previous studies showed that the vertical vibration levels of the truck in Iran are higher than in most countries. Apart from driving quality, these results can be explained by the type of suspension system, amount of load, and road quality.Conclusion In sum, the results can be used to simulate the truck transport conditions by programmable vibration simulators to reproduce the vibration conditions for package testing on Iran roads. The findings are highly interested in improving packaging design, reducing fruit damage, maintaining shelf life, smart transportation, and related industries. Thus, potential future works are lab simulations, optimizations of packages, and the development of a real-time vibration monitoring system.
Kh. Mohammadi; H. R. Ghasemzadeh; H. Navid; M. Moghaddam; H. Ghaffari
Abstract
In this research the quality of walnut kernels under impact loading were studied. Due to unavailability of specific varieties of walnut in Iran, the tests were carried out on the available genotypes. Three different genotypes from walnut orchards of Azarshar region were selected and were collected in ...
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In this research the quality of walnut kernels under impact loading were studied. Due to unavailability of specific varieties of walnut in Iran, the tests were carried out on the available genotypes. Three different genotypes from walnut orchards of Azarshar region were selected and were collected in 2009. A drop test device was designed and constructed to perform the experiments. The impact tests were performed considering five factors in a factorial experiment using completely randomized design with five replications. The factors were genotype, moisture content, geometrical mean diameter, load direction with three levels and the hammer drop height (five levels). The effect of these factors on kernel quality was examined. Walnut cracking assessments and kernel quality were evaluated by well-defined criteria. Generally, by increasing the moisture content, the percentage of broken kernels decreased while the number of unbroken kernels increased and the quality grade of the kernels improved. The percentage of broken kernels increased as hammer drop height increased. Soaking the walnuts in water for 3 hours, with transverse loading (in Y direction) and hammer drop height of 35cm were formed the best set of walnut cracking parameters for obtaining quality kernels.
