Iranian Journal of Biosystems Engineering
Year:2020 | Volume:50 | Issue:4 |Papers Count:23

Aging tractors is one of the biggest challenges facing the Iranian agricultural sector which reduces the level of mechanization level. In this regard, the aging status of tractor fleet and repair power of Khuzestan province was investigated. For this purpose, existing tractors were zoned in two categories less and more than 13 years old, using ArcGIS software. Due to the high number of active tractors with more than 20 years of life, these tractors were zoned across the province. Aging factor of tractors was calculated for each individual county and the reasons for using old tractors were investigated using AHP method. A combined index entitled repair power was designed using information entropy and the counties of Khuzestan province were ranked based on that. Results showed that the largest number of tractors with over 13 years of age belonged to Ahwaz and Hendijan counties. Highest aging factor belonged to Bagh-e Malek County. Low financial ability of farmers was identified as the most important reason for using tractors over 13 years of age. The value of calculated repair power index indicates weak repair power in Khuzestan province. There is no correlation between aging factor and repair power, but aging factor had negative correlation with the number of repairman, a criterion of repair power index.

In this paper, the simulation of green peas drying process in a hot air-Infrared dryer was carried out using two-dimensional finite element method. For this purpose, the mass transfer governing equation with initial and boundary conditions were derived. The system of first order differential equations were developed by using finite element method with Galerkin approach. To simulate drying process and solve the differential equations, a Matlab program code was developed. The drying simulation process was performed with combinations of four infrared power densities (0, 2000, 4000, and 6000 W. m-2), three levels of drying air temperatures (30, 40, and 50 ℃ ) and three levels of drying air flow rate (0. 5, 1. 0, and 1. 5 m. s-1). Finally, in order to validate the developed model, the simulation results were compared with experimental data resulted by a hot air-Infrared dryer. The minimum, maximum and average relative errors between experimental and predicted data by finite element method simulation were 2. 21%, 3. 77%, and 2. 50%, respectively. The model has reasonable accuracy and high efficiency for predicting the moisture content variation of green peas during drying process and can provide more information on the moisture transfer without running any experiments, so that it can be useful for designing dryers.

The present study analyzed the energy flow of this product by the cumulative energy demand (CED) and cumulative exergy demand (CExD) method by providing a life cycle inventory of greenhouse Primrose production. The required data through interviews and questionnaires were collected from greenhouse owners in Savojbolagh. Based on the results, the total CED and CExD values for one bush of Primrose were calculated as 8. 45 and 8. 24 MJ eq., respectively. Among the impact categories of the CED method, non-renewable-fossil had the largest share with 8. 43 MJ eq. that 66% of it was related to direct energy consumption in the greenhouse. Also, 8. 20 MJ eq. CExD was related to the non-renewable-fossil impact category that direct energy consumption in the greenhouse had the most important role in it. The energy consumption for the production of one bush of Primrose resulted in the emission of 0. 20576 kg of carbon dioxide equivalent.

The present study investigated the depletion of natural and fossil resources in rice production process in three Northern provinces (Mazandaran, Guilan and Golestan) in two types of regular cultivating systems (conventional and mechanized) and two types of rice (low and high yield). Also distributed pollutants and social costs were estimated in different rice and straw management. The highest final index was obtained to 6. 56 (low yield varieties, mechanized cultivation, Golestan province) and the lowest level was 4. 02 (high yield varieties, conventional cultivation, Guilan province). Results of emission of pollutants showed that in first scenario (straw burning in the field) pollutant emissions were much higher than the second scenario (straw packing for animal feed). Also, the highest social cost for burning per hectare of straw was 182. 76 $ (high yield varieties, traditional cultivation, Guilan province) and the lowest value was 105. 34 $ (low yield varieties, traditional cultivation, Mazandaran province).

Efficient use of energy inputs in crop production is an important goal in sustainable agriculture. The purpose of this study was to investigate energy consumption in two irrigation systems (flood and sprinkler irrigation system) for agricultural production including wheat, barley and alfalfa. Required information including total inputs, machinery and human labor, were collected from a 100 hectare farm placed in central region of Hamadan province. The data belonged to the 2017-218 production period. The results revealed that the energy ratio in the sprinkler irrigation system was higher than flood irrigation system for all crops. The results also showed that use of sprinkler irrigation system led to decrease water consumption in all investigated crops. The inputs investigation indicated that electricity input (about 60%) in flood irrigation system and diesel fuel and electricity inputs (about 40 & 33%) in sprinkler irrigation system have the highest energy consumption. The energy forms results showed that crops production depends mainly on non-renewable energy resources (electricity, diesel fuel and chemical fertilizers) in the studied field. According to the results, it was found that although the use of sprinkler irrigation systems increases water productivity, it also increases energy consumption in crop production.

Process control and monitoring in operation of biogas production require various parameters to be measured. Therefore, the methods that express the effect of combination of parameters via robust and inexpensive equipment for fast and accurate measurement have high value. In this research, the relationship between the indicator of daily production of biogas and the signals of the gas sensor array in an electronic nose system designated for biogas has been investigated to analyze and predict the condition of biogas digester in laboratory scale. To produce biogas, 1 liter batch digesters were fed by different combinations of two substrates at mesophilic condition. The Sensor array signals of each digester were divided into two groups of 1 and 2 by the clustering analysis (CA) method, which correspond to the balanced and imbalanced groups, respectively. By analyzing score plot and also correlation loading in the PCA, MQ-4 and MQ-136 sensors were determined as main indicators for detecting the two groups and rest of sensors also contribute to interpret conditions of digesters. At final, to predict the conditions, a pattern recognition was defined by sensor array signals of all digesters in linear discriminant analysis (LDA) that the classification accuracy and resubstitution error were 100% and 0. 0476 respectively, also the accuracy of the prediction pattern was 81. 25%.

No study has been reported about magnetic fields effects on properties of agricultural products in the postharvest stage. In this research a static and dynamic magnetic fields apparatus was fabricated and then the field effects with magnetic flux densities of 2784 and 8240 G and magnetic time of 1 and 12 h on total soluble solids, pH, total antioxidant capacity and total phenolic compounds of pomegranate arils were investigated. Between chemical indicators, the effect of magnetic field on the total antioxidant capacity of pomegranate arils was significant. Dynamic magnetic field with flux density of 8240 G and time of 1 h caused %13/32 increase in antioxidant capacity. But magnetic time of 12 h caused %11/08 decrease in antioxidant capacity. Finally the effect of dynamic magnetic field was more than static magnetic field and magnetic flux density of 8240 G was more than 2784 G.

Seed and grain separation is one of the most important steps in the post-harvest process of agriculture crops. The electrostatic method is applicable for the separation of seed from impurities when conventional methods cannot be used. In this study, a rotating electrostatic separating system with a corona electrode using a high-voltage electric field was designed and evaluated to separate grain from straw particles. The wheat and straw particles vent on belt conveyor and passed through the corona zone under the wired electrode. Each particle gained a certain amount of charge based on its electrical properties. The charged particles passed through the electric field generated by the static electrode as they moved along the ground and rotating cylinder. The resultant force due to the difference in the charge of the particles and the difference in their volume mass caused the difference in the direction of movement of the particles and poured them down into four groups of different boxes. Experiments were carried out at four levels of voltage and three levels of rotational speed of cylinder. Results showed that increasing the voltage from 10 to 25 kV and increasing the speed up to 70 rpm achieved the highest recovery and purity of grain and straw in the specified boxes embedded under the machine.

Production of high purity humic acid with desirable quality properties for different uses is dependent on extraction and purification methods in its production process. The research literature showed that, in order to achieve this, separation of fulvate compounds and inorganic elements from alkaline humate extracted from raw materials is paramount significant. The main purpose of this study was the separation of alkaline humates from fulvates and inorganic elements by membrane separation technology. Spent mushroom compost (SMC) was used as organic waste for extraction of humic compounds including humates and fulvates with alkaline treatment method. Then, a membrane separation process with a mini-pilot system equipped with frame and plate module and polysulfone membrane with molecular weight cut-off 5 kDa was tested. The effect of transmembrane pressure (TMP) with four levels of 50, 150, 250 and 350 kPa on separation performance including permeate flux of fulvates, predominant fouling mechanism, fouling index (i) and fouling resistances as well as chemical and spectral properties and purity percentage of the resulting humic acid ultrafiltered from humate retentates were investigated. The results of this study showed that by increasing of pressure, permeate flux of fulvate compounds increased by 41. 8%. Based on the Hermia model, the predominant fouling mechanism in all pressure levels were cake layer formation. The results of the fouling index (i) showed that all of the fouling mechanisms occurred in the membrane system, and by increasing pressure, complete pores blocking and cake layer formation were occurred faster and earlier respectively. Scanning electron microscopy (SEM) analysis in order to confirm of experimental data of fouling phenomenon showed that by increasing pressure from 50 to 350 kPa, layer thickness accumulated on the membrane surface was increased 3-fold. Evaluation of ultrafiltered humic acid characteristics showed that membrane separation technology played an effective role on chemical and spectral properties of humic acid compared to other purification methods, and increased final purity of humic acid to 87. 8%.

In this study, loquat leaf from Gilan province was analyzed in terms of fatty acids profile, total phenol content, total flavonoids, total tannin, antioxidant activity, type and amount of polyphenol content. Results showed the maximum amounts of unsaturated fatty acids of loquat leaf belonged to linolenic acid (25. 3 ± 0. 15%), oleic acid (18 ± 0. 01%) and linolenic acid (9. 7 ± 0. 15%), respectively. Total phenol content and total tannin of leaf extract of loquat were, respectively, obtained 171. 45 ± 0. 55, 3. 41 ± 0. 22 mg gallic acid/ g dry matter. Total flavonoid content was obtained 790. 4 ± 0. 86 mg quercetin per g dry matter and antioxidant activity was 92. 11 ± 1. 10%. According to high-pressure liquid chromatography (HPLC), caffeic acid had the highest amount of polyphenol compound detected in loquat leaf. Loquat leaf can be consumed as a rich source of antioxidant (such as herbal drink).

In the current research, physico-chemical properties of whey protein isolate (WPI) and its resulting compounds including denatured whey protein isolate (DWPI), cross-linked whey protein isolate (CWPI), whey protein hydrolysate (WPH) and cross-linked whey protein hydrolysate (CWPH) were analyzed. Enzymatic hydrolysis and cross-linking were performed by pepsin (at 37° C for 30 min) and transglutaminase (at 50° C for 20 h), respectively. The obtained results stated that, by moderate heat, DWPI had smaller average size (44 nm) and more zeta-potential rather than native WPI. Intensity of the number of molecules with higher average particle size has been reduced by cross-linking of both DWPI and WPH using transglutaminase. Also, the antioxidant activity of WPH was increased from 0. 398 to 0. 519 through cross-linking and making larger peptide chain. The result of fourier-transform infrared spectroscopy (FTIR) indicated the enzymatic cross-linking owing to the formation of new C− N bonds between the α-carbon of lysine and the primary amine group of glutamine displaced the corresponding band at both CWPI and CWPH samples.

The physicochemical and antimicrobial properties of kefiran-waterborne polyurethane blend film incorporated with Rosmarinus officinalis essential oil with concentrations of 2, 4, 6, 8 and 10 %v/v were investigated. By increasing the concentration of the essential oil, the scanning electron microscopy images showed inhomogeneous and pores in the films structures, while thickness of the resulting films did not show a significant difference (p > 0. 05), but significant decrease and increase were obtained for tensile strength and elongation at break, respectively (p < 0. 05). The water vapor permeability of films was increased up to 6% of essential oil but with further increase, it was significantly decreased (p < 0. 05). The results of inhibition zone test showed that the antimicrobial inhibitory properties of Rosmarinus officinalis essential oil against Staphylococcus aureus were greater than Escherichia coli. Decrease of 2, 1. 7 and 1. 85 logarithmic units was respectively observed in total count of microorganisms, E. coli and S. aureus on ostrich meat during 12 days of storage in the refrigerator. The produced antimicrobial film has the potential to be applied in the packaging of different food.

In this research, some methods such as chitosan coating, nanocomposite film and modified atmosphere packaging were used to preserve button mushroom quality during storage time. Harvested mushrooms were divided in 2 groups, with and without coating (1% chitosan coating), then packed in 3 types of packages (common, Nano and Nano+MAP packages). Nano+MAP packages were contain 10% O2, 10% CO2 and 80% N2. All samples were placed at 4 ° C for 10 days. Physical (moisture and color indecies), chemical (pH and TSS) and mechanical properties (Emod and Fmax) were measured and calculated every other days. In the other hand, O2 and CO2 changes were also measured during storage time. The results showed that chitosan coating, type of packaging, storage time and their mutual effects had significant effects on measured and calculated parameters. Application of nanofilm due to low permeability to O2 and CO2, and also MAP condition had positive effect on control of respiration and preservation of physical, mechanical and chemical properties of mushroom.

The purpose of this study was to evaluate the effect of storage temperature on aroma compounds of probiotic UF cheese containing different concentrations of probiotic Bifidobacterium lactis. For this purpose, UF cheeses with B. lactis cells at two levels (108 and 109 cfu/g) were prepared. The produced cheeses were ripened at 4, 10 and 25° C for 32 days and bacteria viable counts, pH, protein (%), dry matter (%), aroma compounds (μ g/g) and sensory properties were measured. The results showed that an increase in inoculation level and storage temperatures lead to increase in the number of probiotic bacteria. During storage, the number of B. lactis was decreased. pH of all cheese samples was decreased, while acidity and dry matter amounts significantly were increased during storage (p > 0. 05). By increasing the storage time, the amounts of acetaldehyde and acetoin were decreased, while acetic acid at first was increased and then was decreased. Temperature of storage didn’ t have a constant effect on diacetyl and ethanol amounts of probiotic cheese. Sensory evaluation exhibited cheese flavor and texture had no significant differences during storage time and it can be concluded that the probiotic inoculation level of 109 cfu /g and storage temperature (25 º C) were the best conditions for the production of probiotic ultrafiltration cheese.

On one hand, the delicate physics and high sensitivity in the process of paddy conversion to white rice and on the another hand, the importance of quality and its role in the value added of the final product indicate the importance of managing three indicators including quality, cost and time in the rice production. Therefore, the purpose of this study was to achieve optimal layout of different methods with the lowest cost, minimum time and highest quality in the conversion process. For this purpose, all possible methods for each stage of the conversion process in the modern milling units were expressed and a series of fuzzy numbers was considered for them. Risk management was also done by applying fuzzy cutes from zero to one to investigate uncertainty. In the next step, the project management was adopted using the non-dominated sorting genetic algorithm (NSGA-II) and non-dominated ranked genetic algorithm (NRGA-II). Based on the results, the genetics algorithm (NSGA-II) showed better performance in comparison with genetic algorithm (NRGA-II) in solving this problem and finally, the lowest time, minimum cost and the highest quality in the specified conditions (α = 1) were founded 22. 22 hours, 8088170 Rial and 62%, respectively.

The effect of no tillage, minimum and conventional tillage were investigated on some characteristics of soil and machine on alternation of sugar beet, barley, maize, wheat in cold regions of Khorasan Razavi province. This study was conducted in split plot design based on randomized complete block design with three replications. The treatments consisted of soil tillage methods in three levels: conventional tillage, minimum tillage and no tillage in the main plots and amount of plant residues in three levels including: no residues, retaining 30 percent and 60 percent of residues in the subplots. The results showed that no tillage and minimum tillage reduced fuel consumption, operating time, mechanical power consumed in land preparation and planting operations and amount of plant residues returned compared to the conventional tillage. The conventional tillage compared to minimum tillage and no tillage reduced the diameter of the soil clods significantly. Soil tillage methods and amount of plant residues did not have a significant effect on soil penetration resistance.

Raisin is one of the most important agricultural products. In this study, by using the machine vision approach, the quality of bulk raisin was evaluated in two different conditions. In the first case, six classes of good and bad raisins mixture, and in the latter case, 15 classes of good, bad and woody raisins have been studied. Classification results with Linear Discriminate Analysis (LDA) and Support Vector Machine (SVM) showed that the best classification accuracy of 6 classes was obtained by linear SVM method with an accuracy of 85. 55%. The results for classifying 15 classes including good, bad and wood showed that the best result was obtained by linear SVM method but with a lower accuracy of 63. 55%. The results showed that the GLCM method was able to detect the class of raisin bulk product and could replace the expert in raisin processing plants.

Nowadays due to the problems caused by the consumption of high fat products, the use of fat substitutes in foods such as yogurt has increased. In this study, the effect of inulin in 0, 1. 5 and 3% levels and Quince seed gum in 0, 0. 25 and 0. 5% levels was investigated on the qualitative properties of low fat yogurt at 4° C during 14 days of storage. The results showed that addition of inulin significantly decreased syneresis (p<0. 05), at higher levels of Quince seed gum (at 0. 5% level), increasing the amount of syneresis was prevented during storage. Water holding capacity and viscosity increased significantly with increasing inulin and Quince seed gum (p<0. 01), while maximum water holding capacity was 64% and the highest viscosity was 5500 cpoise in a sample containing 3% inulin and 0. 5% Quince seed gum powder. Hardness was increased significantly from 14N to 28N by adding inulin (p<0. 01), at higher levels of Quince seed gum increasing of hardness was prevented over time. The highest color change was in the sample contained the highest amount of inulin and the lowest amount of Quince seed gum on the first day of storage. Optimum content of inulin and Quince seed gum was determined 2. 5% and 0. 4% respectively, in low fat yogurt. In overall acceptance, the optimized low-fat yogurt obtained a higher score than control yogurt (3% fat). The results of this study showed that it is possible to use inulin and Quince seed gum at optimal levels in the preparation of low-fat yogurt.

Rough rice is one of the most important agricultural products and it plays an important role in ensuring food security. The objective of this study was to investigate the effect of high power ultrasound in tempering duration on the drying kinetics of rough rice in a combined far-infrared radiation (FIR) dryer. Tests were conducted in a factorial design at four levels of ultrasound power density (Zero, 0. 5, 0. 75 and 1 kW/kg), four levels of frequency (20, 25, 28, and 30kHz) and three levels of drying air temperature (30, 40, and 50oC). Results showed that mechanical characteristics of rough rice were affected significantly at all ultrasound power and frequency levels at different inlet air temperatures at tempering duration and led to reduction of both drying time and specific energy consumption. So that at power of 0. 5 kW / kg, low ultrasonic frequencies of 20 and 25 kHz and input temperature of 30 ° C while reducing the percentage of cracks in rough rice kernels, they also increase the energy required for healthy seed breakage on average.

Active monitoring of beehive using sensor network that can record all of the hive conditions for recognition of living status of beehives, could help beekeepers to make a proper decision while attacking foreign enemies, and prevent the collapse of the hive. To this end, in this study, an expert system for detection of Merops apiaster attack was developed which is including: temperature, sound, humidity and ethanol sensors. The data was collected for two conditions (i. e. normal and apiaster attack conditions) and different features in two time and frequency domains were extracted. After that, the most significant features were selected and classified using GA (Genetic Algorithm) and K-NN, respectively. According to results, among 19 selected features, 5 features namely spectral entropy, sound energy, sound maximum, alcohol minimum, and natural frequency were selected as the most effective features with 8967, 6018, 1321, 1287, and 809 occurrence, respectively. K-NN classification had 100% accuracy, precision, recall, Fscore, specificity, and Gmean and zero false positive rate which indicates proper performance of expert system for detection of apiaster attack to the beehives.