Research Article
Design and Construction
S. Mollapour; D. Kalantari; M. Rajabi Vandechali
Abstract
Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction ...
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Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction force to the operator. On the other hand, a three-point hitch hole-digger has problems such as the lack of maneuverability in confined spaces and high prices. Meanwhile, preparation of these hole-diggers by most farmers and gardeners has no economic justification. Thus, in this research it has been aimed to handle the mentioned problems and to optimize the working quality of hole-diggers via designing and manufacturing a new hydraulic hole-digger. Materials and Methods To start design the machine, displacement volume and power requirement of the hydro-motor and consequently displacement volume requirement of a hydro-pump were calculated using the appropriate formulas (70.83 cm3, 2.3 kW & 7.5 cm3, respectively). According to available hydro-motors and hydro-pumps in the market and using obtained values of displacement volume, an orbital hydro-motor, BMR-80 model with the maximum torque of 220 N.m and an external gear pump REXPORT-2APF8 with displacement volume of 8 cm3 and flow rate of 12 L.min-1 were chosen. In the following, hydro-pump’s parameters were used to select the internal combustion engine. The engine power requirement was 2.875 kW (3.85 hp); thus according to the available engines in the market, a single cylinder gasoline engine, WX168F-1 model that made in Kato company of China with 6.5 hp power and maximum speed of 3600 rpm was chosen. To transmit the power from the engine to the hydro-pump, a coupling DK-42 model was used. Also, two pressure gauges, LB-250 model with maximum pressure of 250 bars were used in the entrance and the exit of the hydro-motor. An hydraulic oil tank with total volume of 24 liters was made from a sheet metal with thickness of 3 mm. The helical auger used in this research, was made in china by LIONS Company with cone tip, total diameter of 200 mm and pitch of 180 mm. The fabricated digger has a working depth and diameter of 30 cm & 20 cm, respectively; rotational speed between 100-160 rpm and maximum power equal to 6.5 hp. In order to evaluate the stress distribution in the auger set, the static analysis based on maximum dynamic torque exerting on auger’s axle and maximum dynamic force exerting on auger’s blades, was used in SOLIDWORKS 2013 software. The maximum force 214.07 kgf (2100 N) proportional to the maximum exerting torque (210 N.m) from soil to the edge of the auger’s blade were considered in the modelling. Farm experiments were carried out in two citrus gardens with silty-clay and sandy-loam texture based on factorial test in Completely Randomized Design with three replications. Soil moisture content as high and low humidity levels (24.85% and 16.12% in sandy-loam and 25.95% and 16.48% in silty-clay) as the first factor and soil depth as the second factor varied in three levels of low, medium, and high (10, 20 and 30 cm), respectively. The measured parameters consisted of specific fuel consumption, machine efficiency, auger torque, auger power and used energy. To determine the auger’s torque, the oil pressure measurement method with two manometers was used in the entrance and the exit of the hydro-motor. After measuring the time and power needed to dig pits, for determining the used energy, the area under the power-time graph was calculated in Excel software. Also, to determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analysis including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 22 software. Results and Discussion The numerical stress analysis results of the auger showed that the maximum von - Mises stress is occurred in the position of the blade-auger axis connections, with a magnitude of 86 MPa. The obtained experimental results in this study indicated that influence of soil depth and moisture content on the measured parameters were significant. in both soil textures and the influence of soil moisture on machine efficiency was non-significant in the silty-clay texture. With increasing soil depth, measured parameters excluding machine efficiency were increased in both soil textures. In high depth and also in low moisture, regarding to the increasing soil bulk density and shear strength, more torque was needed for the rotating auger in the soil that this has led to an increasing in specific fuel consumption of the device. Regarding the results obtained in this study, minimum specific fuel consumption value of the device (0.0014 liter pit-1) was obtained at the low working depth (10 cm) and the high soil moisture (25.95%) in the silty-clay soil. The hole-digger working capacity at 30 cm working depth and soil moisture content as high and low humidity levels in silty- clay obtained equal to90 and 88 pits per hour and in sandy-loam obtained equal to 101 and 95 pits per hour, respectively. Also, the maximum device’s power (2.548 kW) occurred in deep soil (30 cm) and low soil moisture in silty-clay texture. Conclusion Stress analysis and field qualitative observations results indicated that the fabricated device has sufficient resistance and strength against maximum torque from tested soils. Field evaluation of the fabricated machine showed that pit digging operations in soil is not appropriate in low moisture content because of the high fuel consumption and environmental pollution issues.
Research Article
Design and Construction
M. A. Zamani Dehyaghoubi; K. Jafari Naeimi; M. Shamsi; H. Maghsoudi
Abstract
Introduction It is common to use rod weeders for onion harvesting according to their prevention of root blocking in front of the machine and separation of onion bulbs from soil by shaking. Chesson et al., (1977), used a rod weeder for manufacturing an onion harvester. This machine had a rectangular rotor ...
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Introduction It is common to use rod weeders for onion harvesting according to their prevention of root blocking in front of the machine and separation of onion bulbs from soil by shaking. Chesson et al., (1977), used a rod weeder for manufacturing an onion harvester. This machine had a rectangular rotor axis with 25mm×25mm cross section. The rotor power was provided by a hydro-motor. An investigation into onion losses during the harvesting operation showed that the majority of crop damages have been occurred due to the collision of rods with onion bulbs. Therefore, the objective of this study is to design and evaluate an onion harvester based on rod weeders with the capability of crop harvesting with minimum damage. Materials and Methods The main components of the examined onion harvester are chassis, furrower, and power transmission system and excrescence axes. Rectangular 100mm×100mm and 40mm×80mm profiles with 4mm profile thickness are used to fabricate the chassis. The furrowers were installed on each side of the chassis as the first parts of the harvester that comes into contact with the soil. Power transmission system provided rotation of two axes from both sides of the machine due to the lack of space for working of two chains on the one side. Therefore, a gearbox having one input shaft and two output shafts was selected for the machine. The gearbox output shafts turn the rotors with a reduction ratio of 1 to 3.5. The rotary motion of the excrescence axes cuts and moves the soil located under the onions bulbs upward and finally the onion bulbs are placed on the soil surface. Therefore, excrescence axes can be considered as the main part of the onion harvester. The excrescence shape of the axes were created by star wheels. Star wheels had a hole with a square section in center (30mm×30mm), for installing them on their shaft. Choosing this kind of the connection, dose not let star wheels to move freely. Also to limit the lateral movement of the star wheels on axis, metallic spacers were used between the adjacent pairs of them. To evaluate the machine performance three variable factors were defined: working depth (20 and 26 cm), forward speed (3, 4.5 and 6 km h-1) and rotational speed of the excrescence axes (150, 220 and 290 rpm). The conducted experiments were analyzed in a complete randomized design with three replications. Results and Discussion The analysis of variance showed that the working depth and forward velocity of axis had significant effect (in 5% level) on the success rate of onion harvester. Also the interaction between depth and forward velocity and the interaction between rotational speed of axes and forward speed were significant. The interaction between depth and rotational speed of axes and the interaction between depth, rotational speed of axes and forward speed were not significant. Evaluation of the interaction between depth and forward velocity showed that the most success rate of onion harvesting was in 20 cm depth and forward velocity equal to 3 and 4.5 km h-1. The least success was gained in 26 cm depth with 4.5 and 6 km h-1 forward speed. Evaluation of the interaction between rotational speed of axes and forward speed showed that the most success in the onion harvesting was occurred with a machine having 3 km h-1 forward velocity and 150 rpm rotational speed and also 4.5 km h-1 forward velocity and 220 rpm rotational speed. Conclusion The success rate of the onion harvesting decreased by increasing the working depth of the machine and axes distance to the onion bulbs. Also with excessive forward velocity the success rate of onion harvesting decreased because of difficulties in controlling the tractor guidance in straight line. The best performance of this onion harvesting machine was in 20 cm depth, 4.5 km h-1 forward velocity and 220 rpm axes rotational speed. Adjusting the machine working parameters according to these values, the ratio of the linear speed of the star wheel tips to the forward velocity of the machine (kinematic index) was equal to 0.82.
Research Article
M. Feyzi; A. Jafari; H. Ahmadi
Abstract
Introduction Tree felling is an important part of forest exploitation. According to the condition of Iranian forests, mechanization in these forests has not been grown as it should be. Therefore, a main part of tree felling operations are performed by chainsaw. This machine can cause high level hand-arm ...
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Introduction Tree felling is an important part of forest exploitation. According to the condition of Iranian forests, mechanization in these forests has not been grown as it should be. Therefore, a main part of tree felling operations are performed by chainsaw. This machine can cause high level hand-arm vibration which is one of the main reasons of white finger syndrome. This syndrome affects the nerves, blood vessels, muscles, and joints of the hand, wrist, and arm. Reducing and controlling chainsaw vibrations are unlikely to be achievable without awareness of effective factors of it. So, the effects of various factors should be studied. It seems that, single cylinder engine and the interaction of the chain with wood can be the main reasons of chainsaw vibration. Therefore, in the current study the effects of engine rotary speed and wood type on the vibration acceleration of a common chainsaw have been investigated. In contrast to the previous studies, no-cutting condition as a control sample was added to experiments and the effects of cutting itself were evaluated. Experiments were also conducted in three different engine speeds to investigate the effects of interaction between wood species and engine speed. Materials and Methods The vibration acceleration was measured on three orthogonal axes on the front handle of Stihl-070 chainsaw. The measurements were conducted at three levels of engine speed (6000, 7720, and 8630 RPM) during four operations. The operations include cutting three types of Iranian woods (Beech, Hornbeam, and Alder) and no-cutting as a control sample. The experiments were conducted in split-factorial design where the operation was taken as main plot and different speeds and directions as factors. A single-axis piezoelectric accelerometer (VMI-192) was used to sense the vibration. Vibration signals were received and analyzed by a portable data acquisition system (Easy Viber). The RMS vibration acceleration at one-third octave frequency bands in the center frequency range between 6.3Hz to 1250Hz were calculated from acceleration-frequency vibration spectra. Then, the amounts of frequency-weighted vibration acceleration (ahw) were computed based on international standards. SAS software was used to analyze the data statistically. Results and Discussion The results of ANOVA showed that the effect of operation on frequency-weighted acceleration was insignificant, but the effects of engine speed and vibration axis were significant at the 1% level. When the chainsaw was free of cutting, the vibration acceleration values were lower in lower frequencies and higher in higher frequencies compared to cutting wood operations. There was a significant difference between the vibration acceleration in 6000 RPM engine speed and other two speeds, but the differences between 7720 RPM and 8630 RPM engine speeds was insignificant. However, an increase in engine rotary speed increased the value of frequency-weighted vibration acceleration. The acceleration-frequency vibration spectra had peaks at frequencies in accordance with the engine combustion frequencies (100 Hz in 6000, 125 Hz in 7720, and 160 Hz in 8630). Maximum value of unweighted vibration acceleration was observed during no-cutting operations in 6000, 7720, and 8630 RPM engine speeds to be 77.2, 138.6, and 139.0 m s-2, respectively. Vibration acceleration was highest along the Xh (perpendicular to the palm area) equal to 12.05 m.s-2 followed by Yh axis (along the third metacarpal bone) with the value of 9.12 m s-2. Altogether, the results of these tests indicated that the vibration level of employed chainsaw in this study is very higher than other machines has been investigated by other researchers. Conclusion The effects of wood species and engine speed on the hand-transmitted vibration of chainsaw were evaluated. The operation has not significantly affected the frequency-weighted vibration acceleration. However, cutting operations, increase and decrease the vibration acceleration values in lower and higher frequencies, respectively. The frequency-weighted vibration acceleration had higher values in higher engine speeds. Also, it is concluded that the risk of white finger syndrome among the operators of this type of chainsaw is very high.
Research Article
Design and Construction
S. I. Saedi; R. Alimardani; H. Mousazadeh; R. Salehi
Abstract
Introduction Global increase in the food demand and challenges regarding the water, energy and fertile soil has made it clear that current strategies are no longer efficient for maintaining food safety. Therefore, attention to novel, science-based, seasonal and climate-independent farming methods which ...
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Introduction Global increase in the food demand and challenges regarding the water, energy and fertile soil has made it clear that current strategies are no longer efficient for maintaining food safety. Therefore, attention to novel, science-based, seasonal and climate-independent farming methods which could result in the higher crop quality and quantity is an inescapable decision. Among all agricultural practices and technologies, intensive culture and hydroponic methods in controlled environments play an important role. Materials and Methods To address these challenges, an indoor solar-powered auto-irrigate rotary cropping system (SARCS) was designed and implemented. Arrangement of plants in the surface area of an open-ended drum makes it possible to use space rather than area to maximize the acreage. An embedded fuzzy control system managed the irrigation process based on the plant water requirement predictions, and photovoltaic panels (PVs) was responsible for system electrical energy provision. The drum rotates around its horizontal axis where LED lamps are positioned to provide light to plants. This structure causes the plants gain the light illumination efficiently while getting access to water accumulated in the secondary tank positioned beneath the drum. Fertigation fuzzy control was based on plant evapotranspiration (ET) estimations with temperature, humidity, and light as its inputs. The instantaneous estimated ETs which were measures for root substrate moisture were summed until reaching its critical value which is equivalent to plant readily available water (RAW). This tends to trigger a pump submerged in a primary tank to fill the secondary one up to a predefined height ruled by a level sensor. The solar energy system consisted of PVs, MPPT, inverter, and battery bank. The SARCS evaluation procedure included two valid lettuce cultivation in grow bags filled with the same proportions of perlite and coco peat as a root substrate. The first cultivation used water level sensors to rule the irrigation process (non-fuzzy) while the second one (fuzzy) were governed by fertigation cycle fuzzy control. Results and Discussion The results showed that employing these two modes increased lettuce planting density to about 12 times in the field culture and 4 times in the greenhouse. The energy consumption evaluation revealed that in fuzzy and non-fuzzy approaches the same amounts of energy were needed. But in fuzzy mode the amount of energy consumed per kilogram of marketable lettuce was 74.33% less than in non-fuzzy mode. Fuzzy and non-fuzzy modes utilized 58.81% and 48.41% of the total energy requirements from PVs, respectively. It was calculated that the solar system is able to supply 51.16 % of SARCS total annual energy requirements in Karaj Province. The results of water consumption evaluations revealed that the fuzzy approach could cut the needed water to 24%, and improved the marketable product to 74.47%. For producing one kilogram dry and fresh biomass, fuzzy mode used 50.41% and 55.53% less water than non-fuzzy, respectively. Furthermore, one kilogram marketable product in fuzzy approach needed 56.46% less water than in non-fuzzy. The averaged water needed for growing one lettuce plant in non-fuzzy and fuzzy modes were 15 times less than in field lettuce. The comparison of growth parameters of harvested lettuce in the two studied approaches revealed that fuzzy mode would have significantly higher results in all parameters. Conclusion The results suggested that the development of intensive culture strategies would play an important role in the sustainable agricultural production and food safety. Also, the solar energy utilization in farming practices could save fossil resources and decrease air pollutions. Finally, purposeful irrigation approaches which are based on plant water requirement predictions can significantly reduce the total water consumption and improve products quality. This strategy, therefore can be introduced to other farming practices such as field and greenhouse methods.
Research Article
S. Sadeghzade Namavar; J. Amiri Parian; R. Amiri Chayjan
Abstract
Introduction The artichoke is part of the foods from the vegetable group that provide important nutrients like vitamin A and C, potassium and fiber which used as a food and medicine. In the pharmaceutical sector, dried extracts are used in the preparation of pills and capsules. Dried extracts can be ...
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Introduction The artichoke is part of the foods from the vegetable group that provide important nutrients like vitamin A and C, potassium and fiber which used as a food and medicine. In the pharmaceutical sector, dried extracts are used in the preparation of pills and capsules. Dried extracts can be prepared from the dehydration of a concentrated extractive solution from herbal materials (leaves, roots, seeds, etc.), resulting in a dried powder. The spray drying is widely used in the preparation of dried powders from extracts of medicinal plants, fruit pulps. One of the newly developed spray drying techniques is an ultrasonic vacuum method, which strengths of spray drying by incorporation of ultrasonic atomizer and vacuum chamber. Nowadays, image processing has been applied to food images, as acquired by different microscopic systems, to obtain numerical data about the morphology and microstructure of the analyzed foods. For this purpose, microscopy and image processing techniques could be considered as proper tools to evaluate qualitatively and quantitatively the food microstructure, making possible to carry out numerical correlations between microstructure data, as obtained from the images, and the textural properties of food powders. The textural characteristics of the obtained dried powders are determined by means of a perfect detection by scanning electron microscopy (SEM) pictures, and analyzed with a statistical approach for image texture studies, which calls the gray level co-occurrence matrix (GLCM) technique. The object of this study was to illustrate the application of image processing to the study of texture properties from extract powder using GLCM texture analysis and some vacuum spray dryer conditions effect on the texture features of mass particles and single particle SEM images. Materials and Methods After preparing water extract solution from artichoke leaves, extracts were dried under four conditions of vacuum spray drying (according to Table 1). To study the texture of the obtained dried extract powders, different representative features are extracted from the GLCM matrix. The angular second moment (ASM), which is defined as a measure of the homogeneity of the image, the contrast parameter (CT), which represents the amount of local variations given by differences in the gray values in the image. The correlation value (CR), which is a measure of gray tone linear dependencies in the image depending on the direction of the measure (different θs). The inverse difference moment value (IDM), which, similar to ASM, quantifies the homogeneity of the image, however, using a different equation, the entropy parameter (ET), which is a measure that is inversely related to the order given by the gray tones in the image. Rangefilt and stdfilt calculates the local range and local standard deviation of an image respectively. Entropyfilt calculates the local entropy of a grayscale image also. Parameters (ASM, CT, CR and IDM were analyzed in four directions (0º, 45º, 90º, and 135º). Results and Discussion The results of analysis of variance showed that, the difference between the textural features of a single particle and mass particles in four different conditions vacuum spray dryer was significant statistically. Texture analysis was demonstrated that larger ASM, CR, and IDM values indicate less roughness, whereas larger CT and ET values indicate more roughness. At lower inlet temperature and higher vacuum pressure, water diffusion in the material to be slower and allowing the deformation process in the particles to be more pronounced. Consequently, it was possible to observe that generated smaller particles are rougher and less spherical. When the concentration is increased, due to the constant concentration of the additive, the ratio of excipient (lactose) to extraction decreased, as a result were formed a greater number of particles with rougher surfaces. According to these conditions, the values of CT, ET, rangefilt and stdfilt were larger while ASM, CR, and IDM values were smaller. By analyzing the effect of the angle on the oriented textural characteristics, the contrast and correlation parameter were maximum at the angles of 45 and 135 degrees and 0 and 90 degrees respectively. Conclusion Image processing could be auxiliary tools for understanding and characterizing complex systems such as food and biological materials. In this study imaging-based technique was developed to evaluate the texture properties of artichoke leaf extract powder at different conditions of vacuum spray drying. The use of higher temperatures and lower vacuum pressures contributed to faster evaporation rate and production of smoother and larger particles, thereby increasing ASM, CR, and IDM values and reducing CT, ET, Rangefilt and stdfilt. Furthermore, the contrast and entropy parameters showed inverse trends in comparison with correlation, energy and homogeneity. Decrease of solution concentration resulted in the more presence of lactose in the composition of extract/excipient improves the textural properties of powders. The direction parameter had also affected on GLCM textural features. Two oriented textural characteristics (contrast and correlation) also showed significant differences with respect to the nature of particle texture in different directions of measurement. The obtained data extracted from image analysis may provide valuable information to understand the role of structure with respect to product functionality.
Research Article
A. A. Jafari; E. Tatar
Abstract
Introduction Science of rheology has numerous applications in various fields of the food industry such as process assessment, acceptance of products and sales. Fluid behavior changes during processing due to an adverse change in the consistency and due to the combined operations such as mixing, heating, ...
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Introduction Science of rheology has numerous applications in various fields of the food industry such as process assessment, acceptance of products and sales. Fluid behavior changes during processing due to an adverse change in the consistency and due to the combined operations such as mixing, heating, cooling, etc. In this regard, viscosity is an important factor for quality assessment in most of the materials. To measure the viscosity, Viscometer devices are used which are directly in contact with the material. Working with these devices is time consuming, costly, under the influence of human factors and in some cases periodic calibration is required. Materials and Methods Date syrup was used as a viscous material in this study because it industrially is produced. An apparatus including a reservoir with an outlet orifice at the bottom was made to provide free flow of the liquid. Two sets of circular and rectangular orifices with different dimensions were used to investigate the effect of the orifice characteristics on the shape of the flow. Firstly, date syrup viscosity was measured by a conventional viscometer at 5 temperature levels and 6 concentration levels and behavior of the syrup were studied. Free flow of date syrup was photographed in the aforementioned temperatures and concentrations. On the other hand extracted features from the images were used as inputs to the neural network to give outputs as a fluid flow behavior index and consistency index. Measurement data were divided to three sets including training, validation and test sets whereas 70% of the data were used for training the neural networks, 15% as the validation set and 15% for testing the networks. Results and Discussion Results showed that similar to most of the liquids, viscosity of date syrup decreases when temperature increases. The experiments also revealed that the date syrup behavior is expressible with power law and can be determined using power equation. Date syrup has different behavior at different concentration levels. It changes from a pseudoplastic liquid to a Newtonian and then a dilatant liquid when concentration increases. Flow behavior index and consistency index corresponding to all three behavior of the fluid were determined. Results showed that the neural networks were able to accurately estimate the behavior and consistency indices with coefficient of correlations up to 0.99. Networks with three hidden layers were completely suitable for the estimation of the indices. These results revealed that in spite of different behavior of the liquid ranged from pseudoplastic to dilatant, the method was still able to determine the apparent viscosity of the fluid. Although the circular orifices were more efficient in determination of the indices than the rectangular orifices, there was not a significant difference between the uses of circular or rectangular orifices as well as no significant different between the orifices with different dimensions. The correlation between the actual and estimated values for fluid flow behavior index and consistency index was 0.98 whereas the mean square error of the validation sets was about 0.0138 which showed the accuracy of the method. Conclusion In this study a new method of viscosity determination was proposed. Machine vision was employed to estimate the viscosity based on the visual characteristics of the fluid free flow. Date syrup as a liquid with different rheological behaviors was used to assess the performance of the method. The strong correlation between the extracted features and fluid flow behavior index as well as a consistency index proved the reliability and accuracy of the method for viscosity estimation.
Research Article
H. Mohamadi-Monavar
Abstract
Introduction Field management is a part of precision agriculture (PA) which has positive environmental and economic effects on quality of plant productions. Nitrogen needs of plant, depends on climate conditions and growing pattern. The optimum of nitrogen fertilizer is varied from fields to fields. ...
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Introduction Field management is a part of precision agriculture (PA) which has positive environmental and economic effects on quality of plant productions. Nitrogen needs of plant, depends on climate conditions and growing pattern. The optimum of nitrogen fertilizer is varied from fields to fields. Nitrogen management causes uniform shape and size of potatoes, on the other hand decreases the inward and outward damages (Stark and Brown, 2003). Between different herbal indices, NDVI is the most common for monitoring greenness of plants. NDVI was calculated from reflectance in red and NIR bands (equation 1). Greenseeker (GS) is a suitable optical sensor because it is not affected by light and temperature variation or wind intensity. (1) In addition to GS, satellite image was used to evaluate the NDVI of studied potato field. Landsat 8 is the last satellite of this family with new sensors (operational land imager (OLI) and thermal infrared sensor (TIRs)) and additional spectral bands (deep blue invisible (430-450 nm) and shortwave infrared (1360-1390 nm). At the end, support vector regression (SVR) and principal component regression (PCR) or multi-linear regression (MLR) was applied to estimate RMSE and R2. The input of models was synoptic data, and NDVI extracted from GS or OLI. Materials and Methods The study was performed on marfona cultivar of potato field which located in Bahar city, Hamadan. The potato was planted early March and experiments were started after growing the first leaves. The soil texture in the experimented field was sandy loam soil to 75 cm depth. The territory (the southwest corner of the field) was fertigated by poultry manure with content 4.5% of N in order to put shortage of nitrogen down. Metrology station of Bahar city reported the maximum, minimum and average temperature, relative humidity, precipitation and wind velocity which were effective on NDVI variation. The GS was put at a height of 60 cm above the plant and the average of NDVI was obtained by three times measurement. This sensor has red and NIR diodes which reflect and absorb the spectra in 660±15nm and 770±15nm regions, respectively. GS and OLI were applied for measurement every 8 and 16 days, respectively. Satellite images were analyzed two times (30cm height of plant and hilling stage) during the growing. Although, climate changing were effective on NDVI then some image corrections were necessary. Geometric and atmospheric corrections were applied for removing the absorption and distribution error with dark object subtraction and FLAASH algorithm in ENVI 5.3 Software. In addition, GS is a nondestructive and contactless optic sensor which helps farmers to manage nitrogen because using laboratory method is not easy way for them. As well as, OLI provided accurate NDVI which support the accuracy of GS. Results and Discussion In order to correlate NDVI-GS and NDVI-OLI, the third parameter (INSEY) was explained. In season estimation of yield (INSEY) was estimated by dividing NDVI by days after planting (DAP). INSEY index is suitable to predict product potential performance. PCR and SVR methods in Matlab 2011b was used to calculated the relationship of INSEY and NDVI. Also, Red and NIR bands extracted from spectrometer (AvaSpec-ULS 2048- UV-VIS) in the 300-1100 nm region were used in order to support comparison of those sensors. Results showed that the reflectance spectra changed through the growing stage, which is logic because the size and number of leaves were increased and as a result the greenness was enhanced. NDVI calculated with spectra showed more accurate R2 for NDVI-GS (0.94) than NDVI-OLI (0.81). In addition, correlation coefficients of the SVR model between INSEY and NDVI were predicted 0.947 and 0.947 for the GS and OLI, respectively. Conclusion The result of the study confirmed the useful Greanseeker as an accurate and fast technology for prediction of NDVI. Among different regression methods, SVR showed the perfect results. Since the farm is a commercial one and not belong to the university, it would not possible to test different nitrogen fertilizer treatments. It is obvious that evaluation of field in different consecutive years helps us to codify manual fertilization.
Research Article
S. Mollazehi; H. Sadrnia; M. R. Bayati
Abstract
Introduction In recent decays, the microwave heating treatment is one of the best ways for the pest control. It is difficult to determine temperature in different parts of materials by Thermometer, but we can solve this problem by Comsol Multiphysics Software. In a research, results of a farm test were ...
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Introduction In recent decays, the microwave heating treatment is one of the best ways for the pest control. It is difficult to determine temperature in different parts of materials by Thermometer, but we can solve this problem by Comsol Multiphysics Software. In a research, results of a farm test were consistent with laboratory data and high temperature area was belonged to the outer part of wooden piece (Massa et al., 2015). The numerical simulation of Microwave heating was successfully done for fruits and compared with experimental measurement in two cylindrically and spherically states by Zhao et al. (2011). The results indicated that, the temperature prediction in a wooden piece under heating of a Microwave system was in conformity with experimental infra-red rays data (Rattanadecho, 2006). The outer part of the piece was impressed by inspired heating and the inner part by transmission of heating (Massa et al., 2011). A high frequency structure simulator software, a radiant trumpet shaped antenna with 2.45GHz frequencies, 100 watt electric power were the tools that were used to predict the temperature at a Date Palm Wooden piece at 10, 12, 14 and 16 centimeters (Al Shwear and Remili, 2016). Microwave pretreatment was studied with two factors of Microwave radiation (170, 450, and 850 W) and Microwave duration (2, 6, and 10 min). It can be concluded that the Ozonolysis is the most effective pretreatment regarding to saccharification percentage of sugarcane bagasse (Eqra et al., 2015). This study has been done with the aim of fighting with Rhynchophorus ferrugineus blight by microwave and removing toxins in crops. Materials and Methods Samples features such as physical, mechanical and magnetic once were established in both Tehrans Material and Energy lab and Polymer and Petrochemical Research Center, Then it was simulated by Time_ Temperature profile software. For simulating research by Comsol Multiphysics software, at first sample and chamber sizes were determined and the type of material, meshing, 2.45GHz frequencies and the time duration of heating were measured, respectively. Finally the research was analyzed and Time_Temperature profile which was one of the outcomes of Multiphysics software was determined. A cubic piece of wood (103×86×78 mm) (Fig. 1), a Digital Thermometer and a Microwave are the tools which the researcher used in this sample. The temperature was measured at three different parts of cub diagonal by Thermometer. At first, the wooden sample was divided in two equal parts and a sensor was placed in the middle of it and then it was placed in the Microwave. The primary temperature of sample and Microwaves was 27°C. We turn the Microwave on for a period of 10 minutes, after that we check the wooden piece temperature by Thermometer at 20 seconds intervals. Results and Discussion T-test was used to compare statistical results achieved by simulated and experimental temperature of cubic diagonal. According to T mark at 5 percent level, we can say that there is a significant difference between simulated and experimental temperature at point1, however, there is no such a significant difference at 2 and 3 points. In the following phase, the temperature was compared at two simulated and experimental states by variance analysis test. There was significant difference at 1, 2 and 3 points according to data are shown at figure 4. Moreover, Duncan Post hoc test is shown at figures 5 and 7 that experimental temperature shows no difference at 1 and 3 points but it makes difference at 1, 2 and 2, 3 points. Conclusion Results show that the simulation model can predict the temperature in different parts of a wooden sample. The temperature will be higher as much as the points will be closer to the wave producer resource. In order to control pests in the trunk of a tree, we should use several wave generator systems, instead of ones. It is recommended that cylindrical microwave should be simulated and designed instead cubic ones, because it is better adjusted with tree stock and the wave generator system is placed on this surface so that the temperature will be distributed symmetrically along the diagonal.
Research Article
S. Youneji; E. Ahmadi; A. Alavi Nia
Abstract
Introduction The mechanical impacts occur mainly during harvesting and post-harvesting operations, lead to the breaking of cell membranes in cellular structure that dependS on impact intensity. Furthermore, turgor pressure of potato tissue is influenced by the micromechanical and the physiological changes ...
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Introduction The mechanical impacts occur mainly during harvesting and post-harvesting operations, lead to the breaking of cell membranes in cellular structure that dependS on impact intensity. Furthermore, turgor pressure of potato tissue is influenced by the micromechanical and the physiological changes in the storage duration. Micromechanical changes of potato tissue due to the mechanical impact need to be monitored by microscopic images during storage. Scanning electron microscopy (SEM) is a high-resolution technique used to investigate the micromechanical behavior of potato tissue. Materials and Methods Potato samples (‘Sante’ cultivar), were stored at 5 ± 0.5°C and 85% relative humidity for 16 weeks. By 2-week intervals, potatoes were removed from the storage and then the impact test was done. Experimental factors were impacted energy at three levels of control (no impact was done), impact energy 1 (0.031 ± 0.002 J) and impact energy 2 (0.320± 0.020 J) and the radius of curvature at two levels of (35 and 45 mm). Water content was measured by drying thin slab samples in an oven at 70°C to a constant weight. The cell turgor pressure of potato tissue at 2-week intervals was estimated from the linear regression between turgor values of each mannitol solution (0–0.6 M) and relative volume change. The microstructural changes of impact location on the potato tubers were analyzed by SEM images at 2-week intervals during storage period. The surface and depth sections cutting from the impact location were immediately immersed in 2.5% glutaraldehyde in 0.1 M sodium phosphate buffer (2 h) at 4± 0.5°C. The specimens were then rinsed 3 × 10 min in 0.1 M sodium phosphate buffer (pH 7.2), and dehydrated through an ethanol series, 25, 50, 70, 90 and 100% dry, 15 min each step, 2 × 100%. In this study the HMDS as a high-quality chemical drying was investigated. The sample preparation for SEM observation then followed by chemical drying via HMDS, under a laboratory hood overnight. Analysis of variance test based on completely randomized design (CRD) was considered for all of the data using SPSS 23. Results and Discussion Superior preservation of potato microstructure was obtained by hexamethyldisilazane (HMDS) drying during sample preparation for SEM observation. The MIP software was used for quantitative analysis of SEM images and the microstructural features of potato tissue at the impact location were determined. So that each cell outline was manually separated by drawing the lines along the visible contours of cell walls. Measurement of the impact damage dimensions was done by MIP software for the surface section (major and minor width, w1 and w2) and the depth section (depth, d and major width, w1). The results indicated the significant differences between water content, cell turgor pressure, cell area and cell perimeter over 16 weeks storage. Generally, by increasing impact intensity the water content, cell turgor pressure, cell area and cell perimeter significantly decreased. Also interaction effect of storage time, impact level and radius of curvature for impact damage of potato tissue was significant. Conclusion The cell turgor pressure at the impact location on the potato tubers had the similar trend with the water content. SEM investigation showed that potato parenchyma, which was high preserved by HMDS drying, had consisted of the pentagon and hexagonal thin-wall cells with the average cell area of 23.14 × 103 ± 0.178 μm2, the average cell perimeter of 564.98 ± 2.008 μm at week 0. The higher impact damage was at week 16 of storage, impact level 2 and the radius of curvature of 35 mm compared to the other treatment.
Research Article
H. Kargarpour; T. Tavakoli Hashjin; A. Hemmat; B. Ghobadian
Abstract
Introduction The olive fruit (Olea europaea L.) is so sensitive to impact like many other crops that would lead to mechanical damage and bruising which reduce the quality of it. The olive fruit damage includes a brownish bruise at the bruised location. Most mechanical impact damage occurs during harvesting, ...
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Introduction The olive fruit (Olea europaea L.) is so sensitive to impact like many other crops that would lead to mechanical damage and bruising which reduce the quality of it. The olive fruit damage includes a brownish bruise at the bruised location. Most mechanical impact damage occurs during harvesting, handling and transportation. Bruise sensitivity of two common olive cultivars in Iran (cv. Roghani and cv. Conservolea) was studied by free fall method because of development of the area under olive cultivation in Iran, and necessity to mechanical harvest in near future. Materials and Methods Two cultivar of olive fruit named Conservolea and Roghani were collected from Research Orchard of Horticultural Department of Isfahan University of Technology. A free-fall device was designed and built to accomplish an impact experiment which included a load cell monitoring system to measure impact force. The effect of cultivar, height and mass were studied in a factorial experiment. The factors consisted of two cultivar, height at five levels, and mass at three levels with 10 replications. The experiments were performed according to completely randomized design. The effect of impact force and absorbed energy was also studied for the two cultivars. The dimensions of bruising was measured 24 hours after the tests by a caliper with an accuracy of 0.01 mm. The bruising area and volume was calculated assuming the elliptical model for the bruised region. Experimental data were subjected to analysis of variance (ANOVA). Mean comparison was performed based on least significant difference (LSD) test with. Results and Discussion For both cultivars the bruising occurred under the skin and near to the stone. This could show the effect of stone at bruising. The shape of bruised region was elliptical in cv. Roghani and spherical in cv. Conservolea. The bigger stone index and the lower flesh width of cv. Roghani might be one of the reasons of more volume of bruising in this cultivar. This variety could be due to less sphericity in cv. Roghani than cv. Conservolea. The distribution of bruising was more in Roghani cultivar since it had more oil and less water content that might led to more bruising distributed under impact condition so the volume of bruising was more than Conservolea cultivar. The effects of cultivar, height and mass were significant on area and volume of bruising. Increasing height and mass significantly resulted to increase the area and volume of bruising for both cultivars. The bruise area and volume were significantly higher in cv. Roghani. This could be due to differences in physical properties of the cultivars. Roghani cultivar had a higher pit/flesh ratio in comparison with Conservolea cultivars that could contribute to more area of bruising in this cultivar. Increasing the force and energy led to increase in bruise volume for both cultivars. In cv. Roghani, despite the lower levels of force and energy, the bruise volume was more than cv. Conservolea. The reason of lower energy and force in cv. Roghani might be as a result of lower mass than cv. Conservolea. Conclusion The results showed that the effects of independent variables were significant on the volume and area of bruising so that, increasing height and mass increased the volume and area of bruising. The Roghani cv. was significantly more sensitive to bruising compared to Conservolea cv. The energy and force levels were higher in cv. Conservolea since it was heavier than cv. Roghani while the volume of the bruise was more in cv. Roghani. This might be due to the lower sphericity and flesh/pit ratio in cv. Roghani. The shape of mechanical damage which was appeared with a brownish bruising on olive tissue was related to the geometric shape of the fruit i.e. for cv. Roghani and cv. Conservolea the bruising was elliptical in and spherical just like the geometric shape of the cultivars.
Research Article
M. Baghani; M. H. Aghkhani
Abstract
IntroductionIran as one of the largest producers of poultry in Asia and plays major role in feeding the world's population, particularly in the poultry industry. Research about this industry will help to improve the quality and the quantity of products. Increasing of the concentration of toxic gases ...
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IntroductionIran as one of the largest producers of poultry in Asia and plays major role in feeding the world's population, particularly in the poultry industry. Research about this industry will help to improve the quality and the quantity of products. Increasing of the concentration of toxic gases such as NH3 (ammonia), CO2 (carbon dioxide), SH2 and CH4 in poultry houses comes from bird activity inside the barn is one of the basic problems of the farming. Increasing the amount of these gases more than standard level would cause heavy mortality and reductions in the production. Ammonia is one of the most toxic gases in poultry houses, which must be controlled. Different studies have been carried out on measurement of ammonia emissions from poultry houses to reduce energy consumption and reduce emissions of ammonia. But no specific study has been found on ammonia emissions in Iran and there is no reliable documents of ammonia emissions from poultry in this country.Materials and MethodsIn this study a poultry house with 18 thousand chickens was used to measure the emission rate of ammonia, the effect of temperature, moisture and age of chickens on emissions of ammonia in Sabzevar city. The barn was equipped with semi-automatic mechanical ventilation. At the first step of this research all sensors was installed for data collection, i.e., air velocity, temperature, humidity and ammonia concentration. Recorded data information were stored in a central computer. Five digital sensors, model AM2303, have been used to measure the temperature and humidity of the ambient air quality. The concentration of ammonia in the air inputs and outputs of the farm was measured using an ammonia sensor model TGS2444 every 10 seconds throughout the study and recorded in the central system. The average speed of the exhaust air was measured using the hot wire anemometer probe for every fan. The outputs of all sensors was converted to digital data and transferred to the central computer using RS485 cable in each module. Converting of the sensors output to digital data reduces changing the data and probable errors. Ammonia emission rates was found by calculating the concentration of ammonia and measuring the rate of input air and fans exhaust air by ammonia gas equilibrium equation. Relation of the ammonia emission rate was achieved using affective factors such as age of the birds and inside air humidity and temperature by regression method.Results and DiscussionThe average rate of ammonia emission during broiler growing were measured 89 mg per day for each bird. Ammonia emission rates increased until the age of 37 days and then decreased after the age of 37 days. Age of birds has the highest impact coefficient and temperature and relative humidity of the barn have the least impact coefficients on the ammonia emission rate. The ammonia emission rate has also increased by increasing the age of the bird, temperature and relative humidity of the air. Comparing of the ammonia emission rate derived from regression equation with real conditions showed that the regression equation method has a high precision for estimating the ammonia emission rate.ConclusionIt is showed that the results of this research can predict the ammonia emission rate in the poultry houses and predict the required ventilation rates to minimize the amount of ammonia concentration. The results of this study can be used for automatic control system to minimize energy consumption in the poultry houses. According to the results, the reduction of temperature and humidity in poultry house can be used to reduce the ammonia level.
Research Article
S. Haroni; M. J. Sheikhdavoodi; M. Kiani Deh Kiani
Abstract
Introduction One of the most important sources of the sugar production is sugarcane.Sugar is one of the eight human food sources (wheat, rice, corn, sugar, cattle, sorghum, millet and cassava). Also sugarcane is mainly used for livestock feed, electricity generation, fiber and fertilizer and in many ...
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Introduction One of the most important sources of the sugar production is sugarcane.Sugar is one of the eight human food sources (wheat, rice, corn, sugar, cattle, sorghum, millet and cassava). Also sugarcane is mainly used for livestock feed, electricity generation, fiber and fertilizer and in many countries sugarcane is a renewable source for the biofuel. The efficient use of inputs in agriculture lead to the sustainable production and help to reduce the fossil fuel consumption and greenhouse gases emission and save financial resources. Furthermore, detecting relationship between the energy consumption and the yield is necessary to approach the sustainable agriculture. It is generally accepted that many countries try to reduce their dependence to agricultural crop productions of other countries. The being Independent on agricultural productions lead to take more attention to modern methods and the objective of all these methods is increasing the performance with the efficient use of inputs or optimizing energy consumptions in agricultural systems. Energy modeling is a modern method for farm management that this model can predict yield with using the different amount of inputs. The objective of this study was to predict sugarcane production yield and (greenhouse gas) GHG emissions on the basis of energy inputs. Materials and Methods This study was carried out in Khouzestan province of Iran. Data were collected from 55 plant farms in Debel khazai Agro-Industry using face to face questionnaire method. In this study, the energy used in the sugarcane production has considered for the energy analysis without taking into account the environmental sources of the energy such as radiation, wind, rain, etc. Energy consumption in sugarcane production was calculated based on direct and indirect energy sources including human, diesel fuel, chemical fertilizers, pesticides, machinery, irrigation water, electricity and sugarcane stalk. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents. Input energy in agricultural systems includes both direct and indirect energy and renewable and non-renewable forms. Direct energies include human labor, diesel fuel, water for irrigation and electricity and indirect energies consisted of machinery, seed (cultivation of sugarcane has been done with cutting of sugarcane instead of seed), chemical fertilizer. Renewable energies include machinery, sugarcane stalk, chemical fertilizer while non-renewable energy consisted of machinery, chemical fertilizer, electricity and diesel fuel. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents. The amounts of GHG emissions from inputs in sugarcane production per hectare were calculated by CO2 emissions coefficient of agricultural inputs. Energy modeling is an attractive subject for engineers and scientists who are concerned about the energy management. In the energy area, many different of models have been applied for modeling future energy. An artificial neural network (ANN) is an artificial intelligence that it can applied as a predictive tool for nonlinear multi parametric. Artificial neural network has been applied successfully in structural engineering modeling ANNs are inspired by biological neural networks. Results and Discussion The total energy used in the farm operations during the sugarcane production and the energy output was 1742883.769 and 111000 MJha_1, respectively. Electricity (52%) and chemical fertilizers (16%) were the most influential factors in the energy consumption. The electricity contribution was the highest due to the low efficiency of energy conversion in electric motors which were used for irrigation in the study area. In some areas, inefficient surface irrigation wastes a lot of water and energy (in forms of electricity). Another reason is that electricity energy equivalent for Iranian electricity production is higher than developed countries because Iran’s electricity grid is highly dependent on fossil fuels, so that 95% of the electrical energy in Iran is generated in thermal power plants using fossil fuels sources. In addition, the electricity transmission system is too old. GHG emissions data analysis indicated that the total GHG emissions was 415337.62 kg ha-1 (CO2eq) kgCO2eq ha-1 in which burning trash with the share of 62% had the highest GHG emission and followed by electricity (32%), respectively. The ANN model with 7-5-15-1 and 5-5-1 structure were the best model for predicting the sugarcane yield and GHG emissions, respectively. The coefficients of determination (R2) of the best topology were 0.98 and 0.99 for the sugarcane yield and GHG emissions, respectively. The values of RMSE for sugarcane production and GHG emission were found to be 0.0037 and 4.52×10-6, respectively. Conclusion The statistical parameters of R2 and RMSE demonstrated that the proposed artificial neural networks results have best accuracy and can predict the yield and GHG emission. It is generally showed that artificial neural networks have good potential to predict the yield of the sugarcane production.
Research Article
H. Zaki Dizaji; N. Monjezi
Abstract
Introduction Mechanized harvesting of sugarcane by harvesters and the lack of proper management of harvesting, increase the cost of production and eventually become unprofitable. In the case of sugarcane harvester, because the systems are used to be repaired, increasing in system consumption will reduce ...
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Introduction Mechanized harvesting of sugarcane by harvesters and the lack of proper management of harvesting, increase the cost of production and eventually become unprofitable. In the case of sugarcane harvester, because the systems are used to be repaired, increasing in system consumption will reduce machine reliability (Failure rate will increase). So, timely annual overhaul has effective role in enhancing the reliability of sugarcane harvesting machines. Because of time importance indicator for reducing timeliness cost and work breakdown, project scheduling techniques and work study especially network models are used. In this study, because of the ability of GERT networks capabilities in planning and scheduling, GERT networks were used and overhaul scheduling of sugarcane harvester in Amir Kabir Agro-Industry of Khuzestan province, Iran as a case study was analyzed. Materials and Methods The study was carried out in Khuzestan province of Iran in 2016. Data were collected from variety sources such as opinions and comments of experts and reports and statistics of Sugarcane Agro-Industry. All activity times are given in hour. At first, the project activities are determined and the work breakdown structure was drawn. Finally, GERT network was plotted and analyzed. GERT is a procedure, which combines the disciplines of the flow graph theory, Moment Generating Function (MGF) and Project Evaluation and Review Technique (PERT) for analyzing stochastic networks having logical nodes and directed branches. Each branch has a probability that the activity associated with it will be performed. Therefore, GERT provides a visual picture of the system by means of the corresponding graph and makes it possible to analyze the given system in a less inductive manner. The following steps are employed, when applying GERT: 1. Convert a qualitative description of a system or problem to a model in a stochastic network form. 2. Collect the necessary data to describe the transmittances of the network. 3. Apply Mason’s rule to determine the equivalent function or functions of the network. 4. Convert the equivalent function into the following two performance measures of the network: (a) The probability that a specific node is realized. (b) The moment generating function of the time associated with a node, if it is realized. 5. Make inferences concerning the system under study from the information obtained in the Step 4. Results and Discussion In this paper the GERT method has been presented for operations modeling in overhaul sugarcane harvester. Correct scheduling of the agricultural mechanization project (overhaul) is the required condition for the project success therefore the GERT network of overhaul sugarcane harvester was plotted. A network is a powerful tool for scheduling and simulating a project. The project network is defined as a set of activities performed according to the precedence constraint of the activities. The advantage of the GERT network in the present context is two-fold. Firstly, this procedure gives the visual picture of the inspection system and secondly, it enables a thorough characterization of overhaul sugarcane harvester. In this project, after defining activities, we estimate for each activity as a time. Then we solved the network with the GERT method. According to the materials and methods, the probability and mean of the completion time of overhaul sugarcane harvester obtained. The worth of different parts of the network is calculated. For each node, to conclude about the probability and mean can use the above procedure and predict various events during operations. So with due attention to certain events that are occurring in the tracks of operation, good decisions can be adopted. Time completion of overhaul scheduling of the sugarcane harvester is equal to 1164.64 man-hours. Results showed that the network model is increasingly powerful tool to help project manager who could able to make optimum decision. Conclusion Optimized overhaul planning is a fundamental activity in business profitability because it can increase the returns from an operation with low additional costs. In this paper, a specific scheduling model for an overhaul operations scheduling is developed along with an optimal solution GERT method. The purpose of this paper is studying the application of project scheduling in agriculture, for overhaul scheduling of sugarcane harvester using GERT method in Khuzestan province of Iran. Time completion of overhaul scheduling of sugarcane harvester is equal to 1164.64 man-hours.
Research Article
H. Rezaei; A. Shanaghi
Abstract
Introduction Nowadays, enhancing the impact-resistant and wear-resistant properties of the parts and devices used in the agriculture is necessary to increase the efficiency and lifetime. Among of metals, mild steels due to their properties and low economic cost widely used in the manufacturing of agricultural ...
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Introduction Nowadays, enhancing the impact-resistant and wear-resistant properties of the parts and devices used in the agriculture is necessary to increase the efficiency and lifetime. Among of metals, mild steels due to their properties and low economic cost widely used in the manufacturing of agricultural equipment, but one of their problems is the low wear resistance. So, some methods such as carbon surface hardening, induction hardening, etc., were used to improve the tribological properties. Among of these methods, the nitriding process is an appropriate surface hardening process. In this process, liquid or gaseous of nitrogen atom is provided and then using the appropriate conditions such as heat treatment led to nitrogen atoms penetrate into the matrix structure. Materials and Methods Nine rebar samples of CK45 mild steel with a diameter of 20 mm and a height of 10 mm were prepared with a standard number 1.1191DIN. Firstly, the samples were grinded and polished by alumina powder with particle size of 1 to 3 microns. After cleaning the plasma chamber, samples were placed in the chamber, and the vacuum was created, then plasma nitriding treatment conditions were selected as shown in Table 1. Then phase properties, coating composition, structure and abrasion coating, investigated by using XRD, AFM, FESEM and pin on disc, respectively. Pin on disk wear tests were done according to the standard ASTM G99-90 by pins abrasive tungsten-cobalt with the spherical head (a radius of 5 mm) and under a load of 10 N in the slurry containing soft soil with 10% sand (silicon dioxide), a temperature of 31 °C, humidity 38% and linear velocity of 0.1 mm per seconds. Results and Discussion The curve of XRD, FESEM and AFM images clearly shows the formation of a completely homogenous layer nitride on the surface of the CK45 carbon steel, with a hardness of 810 Vickers and friction coefficient of 0.38. The X-ray diffraction curve indicate the formation of mixed phases ỳ + ε and ε at the surface, and also the presence of α- Fe is due to the passage of X-rays and reaching the CK45 carbon steel substrate. The presence of an unknown peak that was not detected by standard cards, can be related to the presence of nitride in the diffusion layer. According to the AFM, FESEM images and Debye Scherrer relationship, the average particle sizes are in the range of 40 to 70 nm, which formed highly uniform structure. The surface hardness profile shows that the highest hardness of compound layer ỳ + ε may be due the influence of nitrogen in the surface layer to create a complex between surface and Fe4N and Fe3N, which respectively contain more than 7.9% nitrogen, ε-phase and phase ỳ contain about 6% nitrogen. It is noteworthy that the low flexibility, hard and brittle properties of ε-phase leads to higher hardness and thickness of the compound layer that is about 10 microns. Then, increasing distance from the surface cause to present a diffusion layer, which can include nitrides alloy with iron nitride, the thickness of this layer is about 70 microns. It could be notable that the change in the slope of the graph was shown from 40 to 60 microns, it would due to the emergence of fine-grained alloy nitride in this area, which deposit at grain boundary and can be reduced mobility of slip systems and prevent their movement. Fracture energy of the mild steel and plasma nitriding treated mild steel are 57.5 and 57.3 J.cm-2, respectively, which reflects that the softness or flexibility behaviors of samples are similar. However, the abrasive wear mechanism of the silica-based minerals is the main cause of the degradation and the wear of parts and agricultural implements. According to the coefficient of friction behavior, the compound layer of composition as well as its supporting layer, diffusion layer, both resulting in improved abrasion resistance are as follows: • Increasing hardness, reducing the coefficient of friction and also preventing scratches on parts of the silica minerals. • Increasing adhesion of the coating by the diffusion layer leads to increase the tolerance, as well as tapering hard coating layer and substrate combination is resulting in increased longevity. Conclusion Plasma nitriding treated of CK45 mild steel at 450 °C cause to the formation of compound layer (ỳ+ ε) with a thickness of 10 micron and diffusion layer with a thickness of 70 microns. The quite smooth, homogeneous and fine grain structure of surface and also formation of compound layer and diffusion layer led to reduce the friction coefficient of the mild steel by nearly 52% along with the stagnation offracture energy of about 57.3 J.cm-2. In fact, the increasing hardness of the surface led to reduce its coefficient of friction and improve wear performance of parts.
Research Article
G. Khoobbakht
Abstract
Introduction Diesterol is a new specific term which denotes a mixture of fossil diesel fuel (D), vegetable oil methyl ester called biodiesel (B) and plant derived ethanol (E). Recently, much attention has been paid to the development of alternative fuels in order to meet the emission standards and to ...
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Introduction Diesterol is a new specific term which denotes a mixture of fossil diesel fuel (D), vegetable oil methyl ester called biodiesel (B) and plant derived ethanol (E). Recently, much attention has been paid to the development of alternative fuels in order to meet the emission standards and to reduce the dependency on fossil fuel. Biodiesel and ethanol have been considered as major alternative fuels, as they are derived from renewable sources. These fuels are well oxygenated and therefore have a great potential to reduce emissions. Biodiesel is an oxygenated diesel fuel made from vegetable and animal fats by conversion of the triglyceride fats into esters via transesterification. Materials and Methods The engine test bed consisted of a diesel engine, a dynamometer, a gas analyzer and a fuel tank. The control bench also consisted of control units, data logger and a PC. Engine was loaded by a ferromagnetism dynamometer of 400 kW capacity and load was measured with spring balance. The experiments were designed using a statistical tool known as Design of Experiments (DoE) based on central composite rotatable design (CCRD) of response surface methodology (RSM) and the optimum points were found using RSM. Four experimental variables in the present study including the operating parameters, load and speed and the added volume of biodiesel and ethanol in one liter of diesel fuel were considered to be effective factors on the brake power and torque. Designs that can fit as a model must have at least three different levels in each variable. This is satisfied by central composite rotatable designs (CCRD), which have five levels per variable. The most successful and best among the designs is the central composite design which is accomplished by adding two experimental points along each coordinate axis at opposite sides of the origin and at a distance equal to the semi diagonal of the hyper cube of the factorial design and new extreme values (low and high) for each factor added in this design. In the present work, the response surface methodology based on desirability approach is used for the optimization of experiment parameters (load, speed, biodiesel and ethanol volume) for the measured properties of response (brake power and torque). The optimization analysis was carried out using SAS 9.2 software, where each response is transformed into a dimensionless desirability value (d) and it ranges between d = 0, which suggests that the response is completely unacceptable, and d = 1, which suggests that the response is more desirable. Results and Discussion The resultant quadratic models of the response surface methodology were helpful to predict the response parameters including the performance characteristics of engine and further to identify the significant interactions between the input factors on the responses. By increasing the amount of biodiesel, the brake power is reduced compared to diesel fuel. This is due to two factors: the first is concerned with the percentage of biodiesel in the fuel mix because of the low calorific value of biodiesel compared to diesel fuel, calorific value fuel mixture is reduced. On the other hand, due to the high viscosity of biodiesel than diesel fuel combined with an increase in these enhanced features and fuel atomization when spraying will be difficult. It is generally desirable outcome of these two factors have prevented the ignition and brake power somewhat reduced. Increasing the volume percent biodiesel fuel mixture to the engine braking torque is reduced diesel fuel engines in all working conditions. The reason for this decline is the low calorific value of biodiesel compared to diesel fuel. Also, by increasing the concentration of ethanol in the fuel mix engine braking torque is reduced. The reason for this decline in addition to the low calorific value of ethanol compared to diesel fuel may be related to cetane number and low latent heat of vaporization of ethanol. Conclusion The results depicted that low percentages of biodiesel and bioethanol into synthetic fuel also somewhat have same power and torque but increasing biodiesel and ethanol contents into synthetic fuel reduced power and torque. The maximum brake power (79 kW) occurred for the pure diesel fuel (equivalent to D100B0E0) at 2800 rpm and full load (100%) and the most brake power (325 N.m) occurred for the pure diesel fuel (equivalent to D100B0E0) at 1630 rpm and full load (100%).
Research Article
Z. Ramedani; R. Abdi; M. Omid; M. A. Maysami
Abstract
Introduction Life cycle assessment of food products is an appropriate method to understand the energy consumption and production of environmental burdens. Dairy production process has considerable effect on climate change in various ways, and the scale of these effects depends on the practices of dairy ...
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Introduction Life cycle assessment of food products is an appropriate method to understand the energy consumption and production of environmental burdens. Dairy production process has considerable effect on climate change in various ways, and the scale of these effects depends on the practices of dairy industry, dairy farmers and feed growers. This study examined the life cycle of production of dairy products in Kermanshah city. For this purpose, the whole life was divided in two sections: production of raw milk in dairy farm and dairy products in dairy industry. In each section the energy consumption patterns and environmental burdens were evaluated. Based on the results, the consumed energy in dairy farm was 6286.29 MJ for amount of produced milk in month. Also animal feed was the greatest energy consumer with the value of 45.12% that the maximum amount of this value was for concentrate. The minimum consumption of energy was for the machinery with 0.92 MJ in a month. Results of life cycle assessment of dairy products showed that in dairy industry raw milk input causes most of impact categories especially land use, carcinogens and acidification. In dairy farms, concentrate was effective more than 90% in production of impact categories included: land use and carcinogens. Using digesters for production biogas and solar water heaters in dairy farm can decrease fossil recourses. Materials and Methods Based on ISO 14044, standards provide an overview of the steps of an LCA: (1) Goal and Scope Definition; (2) Life Cycle Inventory Analysis; (3) Life Cycle Impact Assessment; and (4) Interpretation (ISO, 2006). In this study there were two sub-systems in the production line: dairy farm sub-system (1) and dairy factory sub-system (2). In the sub-system related to the dairy farm, the main product was milk. Determination of inputs and outputs in each sub-system, energy consumption, transportation and emissions to air and water as well as waste treatment are the requirements of LCI. However each of them has several components. These components are different in both sub-systems. All the detailed data about energy equivalent in dairy farm is shown in Table 1. More detailed data about inventories description of two sub-systems are shown in Tables 3 and 4. The SimaPro 7.3.2 was used for analyzing the collected data for calculating environmental burdens (Pré Consultants, 2012). Results and Discussion Based on the developed models with SimaPro software for dairy products in the factory, various emissions were generated including emissions into the air, soil and water. The most prevalent emissions are summarized in Table 7. In warm season about half of the milk is processed into drinking yoghurt. Since water is one half of the component of this product so more amount of drinking yoghurt can be achieved with lower energy consumption (about 50%). Furthermore, these results indicated that the magnitude of fossil fuels was much greater than all others. It was followed by land use and respiratory inorganics. The most amount of the consumption of the fossil fuels was the production of energy requirements for heating systems at boilers and tractors in dairy factory and farm, respectively. Also the transportation of raw milk to the dairy industry was another source of the pollution. Also the energy consumption pattern in the dairy farm revealed that the concentrate have high contribution in energy consumption. Conclusion Results of the energy consumption pattern showed that the animal feed was the greatest energy consumer with value of 45.12% and followed by electricity (36%). Energy consumption index for the fossil fuel was calculated about 3.8 that is higher than the global index. Production of raw milk in dairy farm is responsible in the production of impact categories especially land use, carcinogenic and acidification with contribution of 97.6%, 78%, and 63%, respectively. Also the amount of CO2-eq was estimated 2.71 kg for the production of 1kg ECM in cold seasons.
Research Article
F. Keyhani Nasab; T. Mesri Gundoshmian; Sh. Zargar Ershadi
Abstract
Introduction Considering the low cost of the wind power production and its relatively good compatibility with the environment, wind farms have shown extensive growth in the past few years. Considering the importance of using the wind power and its advantages, the careful planning is needed to identify ...
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Introduction Considering the low cost of the wind power production and its relatively good compatibility with the environment, wind farms have shown extensive growth in the past few years. Considering the importance of using the wind power and its advantages, the careful planning is needed to identify the available generation potentials in a region or a country to facilitate its increased use. By the end of 2009, the capacity of wind turbines installed in the wind farms of Iran was 92 MW, which demonstrates the significant potential for additional wind farms in the country and suggests investments in the wind power industry are likely cost effective. The main purpose of this research is to assess the potential of wind power for the city of Pars Abad in northwestern Iran. Materials and Methods In order to measure wind power density and wind energy potential, wind speed data collected every 3 hours at a height of 30 m above the ground for 11 consecutive years are analyzed; the data are provided by the Iranian Meteorological Organization and are used in the assessment of electricity production potential in the area chosen for the wind turbines installation. To determine the wind energy potential at a site and estimate the energy output from this site, statistical functions like probability functions are used. There are many probability functions but the Weibull distribution function is usually considered the most useful function for wind speed data analysis due to its simplicity and good accuracy. The Weibull probability density function is defined with two parameters of k and c as follows: (1) f (v) = k/(c ) 〖( v/c )〗^(k-1) exp (- 〖( v/c )〗^k ) After calculating the Weibull function parameters, status of a location for wind energy potential can be assessed. A good way to assess the available wind resources is by calculation of the wind power density. This parameter indicates how much energy can be converted to electricity at a site and can be calculated as follows: (2) P/A=1/2 ρc^3 Г ( (k+3)/k) Wind energy density expresses the wind power density for a given time period T.The wind energy density for a definite site and in a given time period (one month or one year) (T) can be calculated as: (3) E/A=1/2 ρc^3 Г ((k+3)/k) T Results and Discussion In this study, wind speed data collected in Parsabad, Iran, over a ten-year period (2005-2015) are analyzed, and the Weibull distribution parameters c and k, average wind speed, and average wind power and wind energy densities are determined. According to Table 1, the minimum and maximum standard deviations of the average monthly indicators during 11 years in November and July are 0.63 and 2.51, respectively, and the minimum and maximum wind speeds of the average monthly indicators during 11 years in November and June are 2.09 ms-1 and 4.87 ms-1, respectively. The average annual Weibull scale parameter (c) is 3.84 while the average annual Weibull shape parameter (k) is 2.61. The average annual wind power density (P/A) during 11 years is 45 Wm-2, while the average annual wind energy density (E/A) during 11 years is 389 kWhm-2/year. Pars Abad in terms of generation potential of wind energy and based on quantitative classification for wind resource is located in weak to average region. Conclusion Pars Abad with an average wind power density of 45 Wm-2 and average wind speed of 3.41 ms-1 is not a good candidate for wind power plants and it is just suitable for off-grid electrical and mechanical applications such as charging batteries and pumping water for agricultural and livestock uses.
Short Paper
Design and Construction
R. Hadipour Rokni; A. Rezaei Asl; R. Tabatabaei koloor
Abstract
Introduction In most small and medium-size traditional animal farms, silage corn is chopped manually. In order to prepare appropriate chopper for small animal production firms, a small electrical powered chopper was designed and developed. Materials and Methods The machine consisted of different parts, ...
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Introduction In most small and medium-size traditional animal farms, silage corn is chopped manually. In order to prepare appropriate chopper for small animal production firms, a small electrical powered chopper was designed and developed. Materials and Methods The machine consisted of different parts, including chassis, driveline, power transmission, feeding and cutting unit. To provide the power for cutting cylinder and feeding rollers, 3.7 kW and 1.5 kW electro-motors were selected and used, respectively. Power was transferred from electro-motors to the cutting cylinder and feeding rollers by pulley and belts. Feeding entrance area was 62.5 cm2with theoretical capacity of 1.13 kgs-1 and feeding unit power consumption of 0.97 kW. The main parts of feeding and cutting units were analyzed by ANSYS Software. Silage corn was provided at harvest time from the Dashte-Naz, Sari province, and transported to laboratory, immediately. The effect of cutting blades speed (400, 550 and 700 RPM) and feed rollers speed (350, 400 and 450 RPM) on the chopper performance (cutting and feeding energy consumption, chopped corn length and machine capacity) were investigated. The results then analyzed using completely randomized design in triplicates. Results and Discussion Analysis of variance showed that the speed of cutting blades, speed of feeding rollers and their interactions had significant effect on the energy consumption of cutting blades and machine capacity. The effect of speed of feeding rollers was significant on the energy consumption of feeding rollers at 1% level of significance. Also, The effect of speed of chopping blades, speed of feeding rollers and their interactions were significant on the length of chopped corn. Machine capacity increased by increasing in speed of chopping blades from 400 to 550 RPM and decreased by increasing from 550 to 700 RPM. Increasing in the speed of the blades at the moment of impact, caused to effectively cut the stem fibers before being compressed or bent. Increasing the speed beyond 550 RPM provided insufficient time for stem movement toward the blades and therefore, machine capacity decreased. By increasing the speed of feeding rollers, the consumed energy by cutting blades decreased and the energy consumption of feeding rollers, the length of chopped corn and the machine capacity increased. Since the machine capacity is depending on time, increasing in feeding rollers speed, decreased the time for chopping the feed stems resulted decreasing in machine capacity. Also, results depicted that the interaction between speed of cutting blades and feeding rollers had meaningful effect on the consumed energy by cutting blades. The maximum energy consumption was at the blade speed of 700 RPM and the feeding rollers speed of 350 RPM, and the minimum energy consumption was at the blade speed of 400 RPM and feeding rollers speed of 450 RPM. The maximum and minimum length of chopped corns was obtained at the blade speed of 400 RPM and 700 RPM, respectively and correspondingly at the rollers speed of 450 RPM and 350 RPM, respectively. The maximum capacity of the machine was obtained at the blade speed of 550 RPM and rollers speed of 450 RPM. Conclusion Since the length of the chopped corn for animal feeding is 20-30 mm, the optimum speed of cutting blades, minimum energy consumption and maximum machine capacity was obtained as 550 RPM and the optimum speed of feeding rollers was at 400 RPM. For feeding high yielding dairy cows, goats and sheeps that need smaller sized forage, it recommended that feeding rollers speed to be adjusted at 350 RPM. At the same speed, the mean length of chopped corn was 8-19 mm.
