O. Omidi-Arjenaki; D. Ghanbarian; M. Naderi-Boldaji; K. Mollazadeh
Abstract
Introduction The texture of fresh fruit is determined by the structural and mechanical properties of tissue. It depends on climate, maturity, variety and postharvest condition. During ripening, due to loss of turgor, degradation of starch and cell walls, the flesh of apple softens. The relationship between ...
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Introduction The texture of fresh fruit is determined by the structural and mechanical properties of tissue. It depends on climate, maturity, variety and postharvest condition. During ripening, due to loss of turgor, degradation of starch and cell walls, the flesh of apple softens. The relationship between fruit quality and its physiological changes has been widely investigated. Using techniques according to the principles of force-deformation, impact, and vibration tests, texture of fruit and its mechanical properties can be associated, conventionally. In analyzing the vitality of biomaterials; a non-invasive technique based on the optical phenomenon is the Biospeckle method which occurs when the surface of the sample is illuminated by laser light. It seems that because of the fact that the laser light can penetrate tissue, it is possible to obtain information about the texture and cell condition from tissue under the skin. This means that, there would be a chance to detect and monitor the variation of cells and try to make a model to predict mechanical properties. Therefore, the overall objective of this study was to develop prediction models based on biospeckle imaging to predict mechanical properties of ripe Golden Delicious apples. Materials and Methods The 400 fresh and intact 'Golden Delicious' apples were harvested and were prepared for mechanical tests and biospeckle imaging. Biospeckle imaging was carried out first, followed by compression and creep test and then penetration test. During imaging, to avoid environmental reflections, the process was carried out in a dark and closed chamber. Biospeckle activity was saved as a video (AVI format) in a computer for analyzing. The THSP method was used to analyze biospeckle activity in samples. The indices which have been used for analyzing biospeckle images are divided into 3 statistical features and 4 textural features. Apples were cut in half. One of the halves was used for cylindrical sample extraction for uniaxial compression and creep tests and another was used for penetration test. From compression tests the tangent modulus of elasticity, stress and strain of bio-yield and failure energy for toughness calculation were determined. The creep behavior was obtained by fitting the Burger's model to the experimental data. In penetration test, a stainless steel probe with a hemispherical tip was used for peeled and unpeeled samples. For each sample maximum penetration force and energy were obtained. Prediction of mechanical property was carried out using adaptive neuro-fuzzy inference system (ANFIS). To reduce the dimension of the input vector the PCA was used. Four significant adjustments were made in the structure of ANFIS in order to find the best models. The models were evaluated using RMSECV, RMSEP, MBEC, MBEP, RC, and RP. Results and Discussion Models for modulus of elasticity prediction have Rp=0.821, 0778, 0.791, 0.880, and 0.843 for 4 compression rate and secant modulus, respectively. Clearly, the results from this research are encouraging, indicating the potential of using speckle imaging system for predicting apple fruit mechanical properties. Comparing to the all texture analysis techniques, Wavelet and GLRLM provided good results for most properties leading to select them as the best techniques for analysis of biospeckle images because of their consistency in prediction performance. Prediction model for break strain has the highest Rp (Rp=0.920) followed by the retarded time (Rp=0.890), retarded viscosity (Rp=0.886) and maximum penetration force in unpeeled case (Rp=0.883). A lower correlation (Rp = 0.728) was observed for initial viscosity. Conclusion The described optical method based on biospeckle represents an innovative and reliable method for rapid and non-invasive detection of mechanical properties. The results of the evaluation showed that, as time passes, fresh apples due to the loss of water in both the elasticity and the biospeckle activity were dropped. Biospeckle imaging can accurately predict mechanical properties. The average accuracy of best prediction of mechanical properties models was R2=0.899. The present results can provide the basis of future development of in-line quality monitoring during apple quality control.
Design and Construction
M. Tohri; D. Ghanbarian; O. Taki; M. Ghasemi-Varnamkhasti
Abstract
IntroductionIn recent years due to lack of water resources in our country, planting of bare root seedlings of onion has been welcomed by farmers. Considering the desired high dense planting of Iranian farmers, lack of proper transplanting machine has appeared as the main problem. To overcome this problem, ...
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IntroductionIn recent years due to lack of water resources in our country, planting of bare root seedlings of onion has been welcomed by farmers. Considering the desired high dense planting of Iranian farmers, lack of proper transplanting machine has appeared as the main problem. To overcome this problem, some researchers tested a few methods, but none of them reached to complete successfully. As the one of last efforts, Taki and Asadi (2012) developed a semi-automatic transplanting machine with 9 planting units. This machine requires to 9 men to separate and single out a bunch of seedlings. Usage of this machine is very time-consuming and labor intensive. In Iran, transplanting of bare root seedlings is practically performed by hand with a density of 700-800 thousand plants at hectare. The main purpose of this study was designed, manufacture, and evaluation of an automatic metering device that with the separation and singulars of bare root seedlings of onion could get a high density planting.Materials and MethodsFig. 1 shows the main employed idea of this research for separation and single out a bunch of seedlings.As shown in Fig. 1, the metering device consisted of two carrying and separating belts with different teeth forms. Placing seedling bunches between the two belts, the belts move at different speeds in opposite directions and separate seedlings from their bunch.For proper design of metering device system, measurement of some physical properties were necessary. The obtained information was used to select two belts form. A belt with flexible plastic teethes with a height of 6 mm and the distance of 4mm was selected as separator while for carrier, two types of belts were selected: the first was the same as a separator and the second was made of metal teethes. Based on the average thickness of seedling bunch and some pre-tests, the horizontal angle of separator belt determined as α=20 degrees. Theoretical calculations were done to computatingof the needed force of the system. In this section, seedlings were modeled as some solid cylinders with a length of 200 and a diameter of 10 mm. In the mentioned system, it was necessary that the speed of separator belt is more than the speed of carrier belt. Thus, ratio of two linear velocities ( ) of 1.67 and 2.32 were considered for evaluation of the system. For evaluation of manufactured metering device, the effects of three factors, i.e., carrier belt type, ratio of linear velocities of the belts, and number of seedlings in a bunch (n = 30 and n =60), on qualitative planting parameters were studied in a factorial experiment based on completely randomized design with three replications. The studied qualitative planting parameters were miss index, consumed seedlings, miss length, quality of feed index, multiple index, mean, and damaged seedlings.Results and DiscussionThe results of analysis of variance showed that, except of belt type, effects of the two studied factors and all interactions are statistically non-significant on consumed seedlings and miss length indexes. The results indicated significant differences between miss index (P<0.01), multiple index (P<0.05), and mean (P<0.05) as affected by belt type. None of the studied variable had a significant effect on damaged seedlings. Interactions of belt type and ratio of linear velocities significantly affected the quality of feed index (P < 0.01). An increase in ratio of linear velocities in plastic toothed belt lead to decrease of mean and miss indexes, whereas in case of metal toothed belt there is no significant effect on this two indexes. The results also showed that increase of linear velocities for the two types of carrier belt lead to increase of consumed seedlings and decrease of miss length. At the two ratios of linear velocities, miss length in metal toothed is less than plastic toothed belt. ConclusionsCommercial transplanting machines are not suitable for dense planting of onion. In this research an automatic metering device for separation and singularize of bare root seedlings of onion was manufactured and evaluated. The results indicated that the carrier belt with long and rigid teeth, having an angle of attack, could separate seedlings more efficiently. The results also showed a 80 percent increased in uniformity of plant seedlings distances is reachable using the metering system.
Design and Construction
D. Ghanbarian; A. Ghorbani-marghmaleki; M. A. Ghazavi; Sh. Besharati
Abstract
Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011), Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort ...
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Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011), Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort their products by hand which is very time-consuming and labor-intensive. So, there is an essential need for suitable grading and packaging machines especially for the export of almond kernels.Grading, which is sometimes called sorting, is basically separating the material in different homogenous groups according to its specific characteristics like size, shape, color and on the basis of quality. Weighing is one of the best methods for grading agricultural products based on size, but due to its high cost and complexity of operations, usage of weigh size sorting machines is practically limited. So, sizing of most agricultural products is accomplished based on their dimensional attributes such as diameter, length, thickness or a combination of them. Field study shows that recently vibrating sizing machines are used for grading almond kernels. This type of sizing machine is huge, expensive, noisy and it consumes a lot of energy. Thus, the main objective of the present study was the design, development and evaluation of a new prototype of an almond kernel sizing machine. Materials and methods: It is important that the machine could resolve defects of existing vibrating machines. It should provide efficient and cost effective sizing for a wide range of kernel sizes and shapes. Furthermore, it should be of simple construction and be able to accept manual feeding. Previously conducted experiments showed that the thickness of the kernel is the most appropriate dimension for its sizing. Among the different types of dimensional sizing machines, the divergent roller grader which grades the products based on their thickness is considered to be one of the simplest options. So, a divergent roller grader was developed and built in this research. The prototype consisted of two diverging rotating rollers which were made of mild steel with an outside diameter of 95 mm and a length of 700 mm. They were mounted to provide an adjustable slope towards the wide opening end. These roller beds were fixed on a box shaped frame of size 500×1000×1200 mm. The slope and counter-rotating action of the rollers encouraged the kernels to continue moving toward the end where the gap between the rollers was the widest. A tray was fixed at the feeding end of the machine for feeding the kernels. A provision was given to adjust the gap from a minimum to a maximum level. Based on the required activate torques of the rollers, an electric 74 W motor was selected to drive the machine. The power transmission mechanism consists of two pulleys 150 and 250 mm diameters and a V belt type A with a length of 1448 mm. The center distance of the pulleys is calculated to be 410 mm. Standard criterions of weighted sorting error index (C ̅_R), weighted sorting efficiencies index (EW) and operation capacity (Q) were used to evaluate the machine. Practical analysis showed that the machine’s performance is influenced mainly by the slope of the rollers, the rotation speed of the rollers, and the feeding rate of the product. In order to evaluate the performance of the prototype, a factorial experiment in a completely randomized design with three replications for each test was done. The performance evaluation was carried out for three levels of feeding rates (600, 1000, and 1400 kg 8h-1, three levels of slopes (2, 7, and 12 degree), and three rotation speeds of rollers (50, 80, and 110 rpm). Spreadsheet software MSTATC and SPSS were used to analyze the data and the Duncan's multiple range tests were used to compare the means.Results and discussion: Analysis of variance showed that all three studied factors have significant effects on evaluating standard criterions of C ̅_R, EW, and Q at the 1% level of confidence. In this work, an increase in the slope of rollers led to a decrease in C ̅_R, whereas at the same time an increase in EW and Q was observed. It may be because at a higher level of slope the almond kernels slip more effectively on rollers surface. This condition restrains the aggregation of kernels on the first part of the gap between the rollers. So, they have enough time to drop through all of the gap. Experimental results show that as the feeding rate increases, C ̅_R and Q increase, whereas EW decreases. Based on the results of the experiments, with an increase of rotation speed of rollers from 50 to 110 rpm, the C ̅_R decreases up to %6.5, and EW decreases about %6. Study of interactions showed effects among which only the interaction of slope and rotation speed of rollers significantly affects all standard criterions. The results also showed that the operation capacity (Q) was significantly affected (P≤0.01) by the interaction effects between the feeding rate and the slope of rollers, and the feeding rate and the rotation speed of the rollers. The mechanical damage to almond kernels in the form of external damage such as cracks and scuffing was almost zero, which is a very important advantage of this machine in comparison with the other sizing machines. Conclusions: In this research, a divergent roller sizer was designed, developed and evaluated for almond kernels.The results showed that the best machine operation is obtainedat a feeding rate of 1000 kg 8h-1, slope of 9 degrees and rotation speed of 110 rpm. In this situation, the prototype could reach weighted sorting efficiencies index of 80% and operation capacity of 830 kg in an 8 hour work shift with weighed sorting error index of 23%.
D. Ghanbarian; M. Shirvani; M. Ghasemi-Varnamkhasti; H. Golestanian
Abstract
Unfortunately despite the great ranking of Iran for apple production around the world, the export potential is not suitable. It seems that one of the major causes of poor quality for Iranian apple varieties is bruising damage of this product. Therefore, in this study, some factors affecting the apple ...
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Unfortunately despite the great ranking of Iran for apple production around the world, the export potential is not suitable. It seems that one of the major causes of poor quality for Iranian apple varieties is bruising damage of this product. Therefore, in this study, some factors affecting the apple bruising were addressed. For this purpose, factorial experiment in a completely randomized design with 72 treatments, including variety factor in three levels (Golden Delicious, Red Delicious and Granny Smith), type of padding surface in four levels (Cardboard on plastic, wood, Rubber on steel and apple) and the drop height in six levels (5, 15, 25, 35, 45 and 55 cm) with four replications were considered. Moreover, the maximum allowable drop heights of apples along with bruising volume estimation models were studied. Analysis of variance (ANOVA) showed that bruising area and volume were significantly affected by all experimental parameters at the 1% level. The comparison test revealed that Granny Smith has tougher tissues and is less prone to vulnerability. Based on the results of this study, the maximum allowable drop heights for the Red Delicious, Golden Delicious and Granny Smith varieties were found to be 12, 15 and 20 cm, respectively. In addition, the effect of apple variety on the dependent parameters was significant. Based on the findings of this study, the bruising due to the impact of apple and apple was lower for the moving apples compared with the stationary apples.
