Original Article
Javad Ashrafi Varkani; Shiva Gorjian; Barat Ghobadian
Abstract
Concentrators have many functions, one of which is their use in the evaporation of liquids. Since a high level of heat is present in concentrator absorbers, it is possible to develop a heat exchanger system that enables the vaporization of salt water. One of the main components of these systems is the ...
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Concentrators have many functions, one of which is their use in the evaporation of liquids. Since a high level of heat is present in concentrator absorbers, it is possible to develop a heat exchanger system that enables the vaporization of salt water. One of the main components of these systems is the heat absorber, which is located at the focal point. In this study, an attempt was made to investigate two geometries of annular and hollow absorbers using the computational fluid dynamics (CFD) method. For this purpose, the working fluid was defined based on the properties of seawater in the Fluent Ansys software, and the creation of the geometry and thermal analysis was considered based on the initial and boundary conditions of the system. The results of the validation of the grid quality showed that the use of a tetrahedral grid with square grid order is suitable for the cylindrical geometry. Due to the dimensional symmetry of the geometry of the ring converter, the use of the simplest grid method leads to a high accuracy of the solver. The thermal analysis of the absorber has shown that with the cavity geometry, the heat distribution at the bottom of the geometry is greater than at the top. The results of the Nusselt number change analysis showed the concentration of thermal stress in the area of the liquid outlet. This stress concentration leads to a shift of the evaporation process from the inside of the chamber to the transfer tubes.
Original Article
Roohollah Yousefi; mohamad younesi
Abstract
Investigating the indices of mechanization in paddy fields in each area is important and also is necessary to select correct rice machines and to use them properly. A study has been conducted in Guilan province to determine the current status of mechanization in paddy fields and to provide solutions ...
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Investigating the indices of mechanization in paddy fields in each area is important and also is necessary to select correct rice machines and to use them properly. A study has been conducted in Guilan province to determine the current status of mechanization in paddy fields and to provide solutions for the problems the farmers are facing with. The indices determining the status of mechanization of rice farming were calculated from information and data in questionnaires, statistical sources, and field surveys. The results showed that the degree of mechanization of tillage, planting with transplanter, spraying, weeding and harvesting (reaper and combine) were 100%, 72.55%, 23.57%, 4.62% and 84.83% respectively. The highest level of mechanization was found in Rudbar with 9.12 hp/ha and the lowest level of mechanization was found in Shaft city with 1.75 hp/ha. The lowest economic efficiency found in Rudbar city with a value of 0.22 ton/hp and the highest economic efficiency found in Shaft city with 1.51 ton/hp. The average of rice mechanization capacity in Guilan province was 404.5 hp.hr/ha. On the average, in the province of Guilan there is one tractor for every 27 hectares of paddy land, one tiller for every 4 hectares of paddy land, one transplanter for every 30 hectares of paddy land, and one harvester for every 60 hectares of paddy land. Low number of self-propelled machines in the province of Guilan comparing to the number of farmers, caused decision-making at the right time for farmers becomes difficult.
Original Article
Jalil Taghizadeh-Tameh; Hossein Mousazadeh; Shahin Rafiee; Nazilla Tarabi
Abstract
Magnetic induction tomography (MIT) is one of the new imaging techniques, and due to its characteristic such as non-intrusive and non-destructive, it has potential for use in many industries, including biological industries, multiphase flows, medical imaging, agriculture and food industries. Main parts ...
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Magnetic induction tomography (MIT) is one of the new imaging techniques, and due to its characteristic such as non-intrusive and non-destructive, it has potential for use in many industries, including biological industries, multiphase flows, medical imaging, agriculture and food industries. Main parts of the MIT system are transmitter and receiver sensors, data acquisition system and image reconstruction algorithm. In this research, performance comparison of four image reconstruction algorithms in applied current magnetic induction tomography (AC-MIT) system was investigated. This system has two innovative annular electrodes as transmitter sensors and 648 coils as a receiver sensor. In order to evaluate the system performance, 12 combinations of target objects were used and image reconstruction was performed using linear back projection algorithm, Landweber iterative algorithm, Tikhonov regularization method and iterative Gauss-Newton algorithm. Size error (SE) and Relative image error (IE) parameters were used to evaluate the quality of the reconstructed images. The results showed that in all combinations of target objects, the IE values of iterative Gauss-Newton algorithm are lower than other algorithms. The results of size error parameter showed that in all four image reconstruction algorithms; increasing number of target objects increases SE parameter. As a general conclusion, it can be stated that iterative Gauss-Newton algorithm has a better performance compared to other algorithms.
Original Article
Ali Farahmandi; Mojtaba Naderi-Boldaji; Maral Ajamian; Mahdi Ghasemi-Varnamkhasti; Saman Abdanan
Abstract
Sugarcane, an important crop in sugar production in the country, is widely produced in Khuzestan province. After harvesting the sugarcane and when delivered to the sugar factory, the cane is shredded. In this study, for measurement of sucrose concentration in shredded cane, the dielectric spectroscopy ...
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Sugarcane, an important crop in sugar production in the country, is widely produced in Khuzestan province. After harvesting the sugarcane and when delivered to the sugar factory, the cane is shredded. In this study, for measurement of sucrose concentration in shredded cane, the dielectric spectroscopy technique in the frequency range of 0-100 MHz was evaluated using a cylindrical parallel-plate sensor with compaction of the shredded cane. 55 samples of shredded cane were taken from the sugar production line of Salman Farsi factory during the harvesting season of 2021-2022 and their reference properties including sugar concentration with three indicators of Brix using refractometry method, Pol using simple polarimetry method and the sucrose measured using double polarimetry were measured. The samples were subjected to dielectric spectroscopy using the capacitance sensor and the dielectric spectra were analyzed for sugar concentration prediction. Multivariate regression analyses of partial least-sugare regresseion (PLSR), principal component regression (PCR) and support vector regression (SVR) were applied for development of prediction models of sugar concentration variables. Validation of the prediction model of PLSR showed a stronger prediction of sucrose (R2= 0.79, RMSE= 0.89, RPD= 2.22) measured using the double-polarimetry as compared to Pol (R2= 0.76, RMSE= 0.8, RPD= 2.07) and Brix (R2= 0.77, RMSE= 0.89, RPD= 2). This result was explained with higher number of OH groups of sucrose molecule as compared to the other sugars existing in the sugarcane juice and the dominant effect of sucrose on the dielectric characteristics of the juice. With optimization and improvement of the accuracy of this method, a simple and cost-effective instrument can be developed for use in sugar industries.
Original Article
Mohammad-Ali Behaeen
Abstract
External and internal damages to seed, due to mechanical forces from processing machines, lead to a decrease in the percentage of germination of seeds. With the aim of increasing the efficiency of saw gin machine in separating the fibers from the seeds in the cotton lint, a factorial experiment was conducted ...
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External and internal damages to seed, due to mechanical forces from processing machines, lead to a decrease in the percentage of germination of seeds. With the aim of increasing the efficiency of saw gin machine in separating the fibers from the seeds in the cotton lint, a factorial experiment was conducted in the form of a completely randomized design (CRD) with three replications. Levels of experiment factors were rotational speed of saws in gin machine at three levels; 300 rpm (S1), 350 rpm (S2) and 400 rpm (S3), seed moisture content at three levels; 3-5% (M1), 6-8 % (M2) and 8-10% (M3), and the cotton seed variety at two levels of Hekmat (V1) and Golestan (V2). Cotton seeds length, width, thickness, geometric mean, and sphericity coefficient were measured. Also, the seed skin thickness index, the amount of visible trash on the seed and fibers, the material capacity of saw gin machine, the seed germination, seed emergence rate, seed vigor index, and relative ion leakage were determined after processing the cotton lint in the gin machine. After data analysis of variance, treatments means were compared with Duncan's multiple range tests and regression equation between test treatments (independent variables) and measured parameters (dependent variables) were done. The results showed that S1M2V2 and S1M1V1 treatments produced the highest and lowest material capacity with 2.40 kg h-1and 1.90 kg h-1, respectively. Considering the same rotational speed and moisture content, the material capacity of the machine in Golestan variety was 12.22% higher than that in Hekmat variety. The regression equations showed that in Hekmat variety, with the increase in the rotational speed of saws in gin machine, the percentage of seed germination increased and the seed vigor index decreased. In the Golestan variety, the regression equations also showed that increase in the rotational speed of saws in gin machine, decrease in the percentage of seed germination and increase in the moisture content, caused an increase in seed emergence rate. Rotational speed of 350 rpm, moisture content of 6-8% and Golestan cotton variety produced the maximum germination percentage and seed germination rate with 93.67% and 24.56 seeds per day, respectively, and it is recommended.
Original Article
Mohammad Shaker; Akbar Jokar
Abstract
In this research, a machine vision system was used and evaluated for seeds of sorghum, cotton and barley. For each type of seed, the performance of the suction device, with three seed plates (with hole diameters of 1, 1.5 and 2 mm) and four suction values (-80, -100, -120 and -130 mmHg) was evaluated. ...
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In this research, a machine vision system was used and evaluated for seeds of sorghum, cotton and barley. For each type of seed, the performance of the suction device, with three seed plates (with hole diameters of 1, 1.5 and 2 mm) and four suction values (-80, -100, -120 and -130 mmHg) was evaluated. In each f suction value, the total number of seeds sticked to the seed plate, the number of singled seeds and the number of sticked seeds on each hole were counted and their percentage was calculated. After that, for the three types of seeds tested, the algorithm for determining the percentage of breakage and the number of seed coding and validation of the algorithm was evaluated in 30 repetitions. The results showed that for sorghum seed, treatment No.1 (seed plate with 1 mm holes and suction value of -80 mm Hg), for cotton seed, treatment No. 5 (seed plate with 1.5 mm holes and suction value of -80 mm Hg), and for barley seed, treatment No. 2 (seed plate with 1 mm holes and suction value of -100 mm Hg), were the most suitable treatments. The validation results of the algorithm for determining the percentage of breakage and the number of seeds for the three types of seeds tested showed that the average accuracy of the algorithm was equal to 100%.
