mohammad hossein abbaspour-fard

Development of new greenhouses based on new cultivation methods is one of the most important practical solutions to increase food production in the world. But despite the higher production efficiency of the product, their energy consumption is very high. To solve the energy problem in these greenhouses, the use of renewable energy as a permanent energy source has been suggested by scientists in recent years. Meanwhile, photovoltaics has been investigated by many researchers as a permanent and efficient energy source due to its obvious features, suitability and very good compatibility with agricultural environments and also with greenhouse structures. The results have shown that for the development of photovoltaic covers for greenhouses, in addition to proper photovoltaic efficiency, it is necessary to provide transparency required for the growth of plant in the visible range. One of the technologies that, while having transparency, can be used as a transparent photovoltaic cover for greenhouses, is luminescent solar concentrator (LSC). This photovoltaic device has several components, among which the waveguide is one of the most important components, and its optimization through physical parameters such as geometric factor and refractive index can improve LSC performance. Based on this, in this research, taking into account the parameters of a greenhouse cover and a photovoltaic module, two waveguides made of glass and PMMA were investigated in the construction of LSCs to investigate the effect of the geometric factor and the optical refractive index and their effect on the optical efficiency and the PCE of LSCs was investigated. The results showed that by increasing the thickness of the waveguide from 4 to 6 mm, which reduces the amount of its geometric factor, and also the use of PMMA waveguide in comparison with glass, which in addition to having strength and transparency in the visible region, has a higher refractive index (1.46), can increase the PCE and optical efficiency of LSC from 0.33% to 1% and 0.98% to 4.27%, respectively.

Tillers (2WTs) are among the types of small tractors that are usually used in greenhouses, orchards, and  paddy fields; they are most useful  in places where it is difficult to move tractors. The existing tillers have only one clutch for power transmission to the gearbox, and they do not have a clutch to guide and steer. For this reason, they have many problems for turning and steering, especially under the trees and changing the movement direction during work. Therefore, in this research, an attempt was made to solve this problem. Two types of plate (disc) and cone friction clutches, which are the most used in agricultural machines, were thought about.The torque generated on the rotors of a 9-hp tiller was calculated while the tiller was running at gear ratio one. The applied forces from the operator (driver) to the clutch plate (disc) for engaging the clutch was calculated. Having the amount of transmission force, torque and available space to the design of the cone clutch, which can be used on the rotary axles of the tiller, was performed using 3D design software (CATIA). To ensure the resistance of parts against failure and their correct operation, static analysis of selected clutch parts that are exposed to maximum stress was performed in ANSYS software. The results indicated that the clutch parts had appropriate strength and hence, would operate safely. Therefore, it can be concluded that it is possible to use the cone clutch on such tillers.Two types of plate (disc) and cone friction clutches, which are the most used in agricultural machines, were considered.The torque generated on the rotors of a 9-hp tiller was calculated while the tiller was running at gear ratio one. The applied forces from the user (driver) to the clutch plate (disc) for engaging the clutch was calculated. Having the amount of transmission force, torque and available space to the design of the cone clutch, which can be used on the rotary axles of the tiller, was performed using 3D design software (CATIA). To ensure the resistance of parts against failure and their correct operation, static analysis of selected clutch parts that are exposed to maximum stress was performed in ANSYS software. The results indicates that the clutch parts have appropriate strength and hence, would operate safely. Therefore, it can be concluded that it is possible to use the cone clutch on such tillers.

The movement of the tractor on the side or lateral slopes causes overturning and, consequently, its damage and, in most cases, may also the driver’s death. More than 50% of accidents are related to overturning. In general, tractor overturning can be in the form of lateral and backward overturning, caused by various factors, one of which is the Sharp and uneven side slopes. In this paper, two controllers are designed as a hybrid unit, the first controller is a fuzzy controller, and the second controller is a Proportional Integral Derivative controller (PID). Simultaneously employing these two controllers, the necessary force for the stability and balance of the tractor on side slopes is determined. The performance of the integrated controller was investigated using the Simulink MATLAB environment. Combining these two controllers creates a combinatory control system that can monitor the tractor’s balance on the go on the side slope to prevent overturning phenomena. The fuzzy controller determines the required force for the tractor’s stability, and the PID controller corrects the amount of this force by considering the existing errors. The information obtained from these controllers, which is in the form of determining the force required for the tractor’s stability, is transferred to a hydraulic actuator to apply this force to the tractor body during overturning conditions on side slopes.

One way of improving the thermal performance of greenhouses is using thermal insulators (thermal shading). In this study, the behavior of a novel dynamic shading system made of two-layer polycarbonate plates containing fluid was investigated by numerical method. In this system, according to the cooling and heating requirements also to control the incoming or outgoing radiation from the greenhouse, the appropriate fluid was pumped into the ducts between the polycarbonate plates by a hydraulic pump. Studying the hydraulic parameters, including intra-duct pressure and fluid velocity between plates, can be very useful for the proper design of the shading to minimize the energy required and run the system. The computational fluid dynamics (CFD) method and standard k-ε turbulence model simulated turbulent flow inside the shading ducts. Validation between experimental and numerical data showed an average difference of less than 5 percent between the experimental and numerical pressure drop data. The maximum velocity value of 0.96 ms-1 was obtained for the ducts inside. In comparison, the system pressure drops in single (series) and triple modes (parallel) it was 3793 Pa for the latter and 3439 Pa for the former, which indicates 9.3% decrease in pressure drop for the innovative and proposed design.

In this research, a combined photovoltaic / thermal solar dryer containing phase change materials (PCM) was designed and fabricated for drying mint leaves. The performance of this dryer was evaluated under the climatic conditions of Mashhad city with a longitude of 59.62 and a latitude of 36.26. The components of this dryer mainly include: photovoltaic panel, solar collector, blowers, phase change material chamber containing paraffin wax and drying chamber. Solar dryer and natural drying in shade as two different drying types were used to perform experiments on mint leaves. The initial moisture content of the mint leaves was 80% which reduced to 12%. The required drying time for the combined solar drying and natural drying was 290 minutes and 1560 minutes, respectively. Eight thin layer drying models available in the literature were fitted to the experimental data in which the Two-term model and the Wang and Singh model were the best fit models for natural and combined solar drying respectively. These models have the highest correlation (highest coefficient of determination and least root mean square error and Chi-square) with the experimental moisture ratio among the other models.

In urban environments, root growth is limited because of limitation of soil and some problems the plants are faced with, for example soil compaction. The aim of this study was to build and evaluate a device that could improve the existing deficiencies for tree roots by increasing soil porosity and permeability through air injection. After construction of the machine, weighing 240 kg, equipped with a 7.5 HP engine and maximum injection pressure of 12 bar, the effects of machine operation and some important physical properties of soil such as porosity and infiltration were investigated. Multiple linear regression was used to investigate the relationship between the independent variables of the device including air pressure at 3 levels (4, 8 and 12 bars) and depth at 2 levels (30 and 60 cm) and the dependent variable of porosity. The results showed a significant regression model among the variables. Also, the regression model estimation error was 1.75%. Based on the results, the system can be reliably designed and manufactured to inject air into the soil to increase porosity.

Precision agriculture is rapidly growing worldwide, which is mainly based on positioning. While with the evolution of technology the accuracy of GPS data is continuously improved, the use of these sensors in the less developed countries is still challenging. The direct price link with the accuracy of the GPSs has led to attempts to use low-cost GPSs. The use of low-cost GPSs comes with various sources of error. In this study, a new method has been proposed to overcome the challenge of improving the accuracy of positioning while reducing equipment prices. The proposed method is based on the nature of the GPS error (random noise and bias) and is divided into two parts. First, the random noise was eliminated by employing the simple classic filter. In this regard, a comparison was made between the Kalman filter, Low-pass filter and the Moving Average filter. The settings of the filters were made in such a way that in addition to reducing the power of random error, it reaches the desired error range in the shortest possible time. The results showed that the Kalman filter was more efficient than the other filters. Bias removal is not possible except by using a DGPS receiver that can receive corrections sent from base stations. To solve this problem, a base station was designed that could send the corrections needed by low-cost receivers. The proposed low-cost differential positioning method leads to a 89% reduction in the horizontal error index, which is the accuracy obtained is suitable for various operations in precision agriculture. Second, the bias was removed by inspiring from DGPS technique, via providing a base station, incorporating three low-cost GPSs. in noise reduction and the proposed low-cost differential positioning at best resulted in 89% reduction in the error index. Such an enhanced accuracy can be used for many applications in precision agriculture.

One of the main issues in internal combustion engines is the reduction of the flow of air into the cylinder and, consequently, the reduction of engine efficiency. To solve this problem, the turbocharger can be used as a proper device in diesel engines to increase the efficiency and performance of the engine. The turbocharger is located in the direction of the exhaust gases to compress the air during the process and direct it into the cylinders to increase the volumetric efficiency as well as more complete combustion to reduce the exhaust emissions. The simultaneous use of turbochargers and intercooler in diesel engines reduces the temperature of the intake air into the cylinder and increases the volumetric efficiency. In order to investigate the effect of turbocharger and intercooler on the operation of the Ferguson 285 engine, a turbocharger with intercooler was used and installed on the engine, and then required tests carried out by hydraulic dynamometer in different speeds of 1000, 1500, 2000 and 2500 RPM at full load. The results showed that the engine torque at different speeds in the presence of turbocharger and intercooler increases by 27.22%. The results also indicated that the installation of turbocharger and Intercooler on a diesel tractor is meaningful in %1 level at speeds of 1500 until 2500 RPM in this engine, so that the presence of a turbocharger and intercooler in the range above 1500 increase the engine performance. Also, the difference in temperature between the intercooler input and output shows that during higher speeds, the temperature difference is higher than the lower speeds, which contributes to the increase and improvement of engine volumetric efficiency. Also, the difference in temperature between the intercooler input and output shows that during higher speeds, the temperature difference is higher than the lower speeds, which contributes to the increase and improvement of engine volumetric efficiency.

Fuel supply for cooking among Iranian nomads have always been problematic job. The use of wood as a source of energy is very common in nomads. Traditional method of firing releases a huge amount of smoke, which may lead to respiratory problems in women. Moreover, collection of wood corresponds to destroy of natural resources. The aim of this study is to assess the feasibility of using ship dung (as the most available biomass in nomadic life), as a cleaner cooking fuel in an improved biogas stove. In this research a micro gasifier biomass cook stove as an improved biomass cook stove was evaluated based on Emission & Performance Test Protocol. Sheep dung pellets of 38 mm length and 13.6 mm diameter was used as biofuel. In addition to measurement of descriptive characteristics, the heating value of fuel was estimated based on elemental analyzing results and the models presented in previous researches. Emission of Carbon monoxide was monitored throughout the test. No smoke was observed during the stove operation. The thermal power of the stove was measured to be 3.4 kW. With the efficiency of 28 percent, 3 L of water got to boiling point in 16 min consuming 440 g of pellet. The average amount of emitted CO was recorded to be acceptable range. The results of micro gasifier biomass cook stove evaluation with sheep dung pellet as fuel showed that, this devise has a good technical and emission performance with this fuel and it can be used for nomad’s household. Further on field research is needed to adjust the stove size and design to the common life style of nomads.

In this study, a software model was developed for the spreader unit of a centrifugal fertilizer and its spread performance was studied with different blade designs to recommend the best suitable blade for spreading of the pellet fertilizer. The blade designs include trapezoid, angled trapezoid, channel (U shape) and angle (L shape) that were compared with the control blade. In order to validate the software's results, a laboratory spreader device was fabricated based on a commercial centrifugal fertilizer machine. The spread pattern of the designed blades was investigated experimentally in a completely randomized design with three replications. The influence of blade design as the dependent variable, on Total Transverse Spreading Pattern (TTSP) and Coefficient of Variation (CV) as the dependent variables, was investigated to achieve the best design for blade in the experimental mode. Results showed that the trapezoid blade, among other blades, had the best spread performance with in the effective swath width during pellet spreading (CV=0.18). Other blades were ranked as angle blade (CV=0.29), channel blade (CV=0.38), angled trapezoid blade (CV= 0.57) and control blade (CV= 0.64) respectively. This ranking observed for both numerical software and the experimental results. Investigation on adaptation and compatibility between the software model and experimental results showed that, for all blades designs, there were acceptable agreements between software model and experimental (R2 ≥ 0.90).

 The basic limitation of biopolymers compared to the petroleum-based polymers is their weak physical and mechanical properties. In recent years, efforts have been made to properly incorporate nanoparticles into the polymer to reduce the limitation of their use in the packaging industry by partially improving the physical and mechanical properties of these films. This study aimed to incorporate zinc oxide nanoparticles into gelatin-biopolymer-based nanocomposite films, in order to improve their physical, mechanical and thermal properties.

Gelatin-based nanocomposite films were prepared by adding different amounts of zinc oxide nanoparticles (0, 0.5, 1.5 and 3%) using the so-called casting method. By performing several tests, different properties of the manufactured nanocomposite films including thickness, density, water vapor permeability, mechanical properties, degree of transparency, color properties and finally, their biodegradability were investigated.

the results showed that increasing the concentration of zinc oxide nanoparticles increased the tensile strength and decreased the elongation-at-break of this biofilm. The results of physical tests showed that increase in nanoparticles concentration reduced the permeability to water vapor from 0.76 to 0.48. Incorporating zinc oxide nanoparticles affected the transparency of the biofilms i.e. their transparency reduced by increasing nanoparticles concentration. By adding nanoparticles to gelatin-based films, thermal properties including glass transition temperature and melting temperature increased. Also, the thermal stability of the biofilms increased from 533.38°C (0.5% nanoparticles) to 559.53°C (1.5% nanoparticles). The results of biodegradability in soil and light showed that with increasing the concentration of nanoparticles, the biodegradability was reduced. This is mainly due to the addition of nanoparticles, which results in a greater bond strength between the components, and consequently the delay in biodegradation.

Considering the present business competitive scenario, the automotive industry is under pressure to achieve higher productivity. A high level of performance and quality standard could be achieved through improving the Overall Equipment Effectiveness (OEE) of the equipment in an automotive industry. Thus, the aim of this study is to investigate the performance measurement through OEE theory in an Iranian automotive industry. Data and basic information collected from the Computerized Maintenance Management System (CMMS) of the production assembly lines. In this case study, two different assembly lines such Peugeot and Sports Utility Vehicle (SUV) were studied. The results indicated that the indices such availability rate, performance and quality for Peugeot assembly line obtained an OEE value of 0.99, 0.70 and 0.38, respectively, and, these indices for SUV assembly line obtained as 0.99, 0.39 and 0.53, respectively. Statistical analysis results of net operating time parameter for two assembly lines revealed that there is significant difference in the confidence level of 5% (P-value < 0.05). In addition, the OEE index for Peugeot and SUV assembly lines gained 0.27 and 0.21 over a period of one year. Consequently, to improve the OEE in the automotive assembly lines, managing the time losses by systematic planning of manufacturing and the implementation of Total Productive Maintenance (TPM) are suggested.

Agriculture is an occupation in which the workers are prone to health problems, particularly musculoskeletal disorders. This job is one of the most strenous and most dangerous work activities with approximately 40% of the engaged population living in the developing countries. Iran is the world's largest producer of saffron (about 94% of the world production). Labour has the highest impact on the production of this crop. In this research, a kind of trolley is introduced in order to reduce the mechanical damages on the body of labors during saffron harvesting, and then the results are compared with traditional harvesting methods. In the experiments, the force and strength percent capability of 20 workers as saffron harvesters is evaluated using the 3DSSPP software. Two methods of saffron harvesting namely the traditional method with two common postures (half sitting and bowing) and harvesting while sitting on the trolley are considered. The different postures for the traditional harvesting methods and harvesting with the trolley were simulated and imported to the software. It was found that the most harm on the farmers occurs in their knees with half sitting. Evaluation of harvesting saffron with trolley showed that it results in the exertion of the least damage to farmers. However, harvesting with trolley exserts the most pressure on the back. However, the pressure is very little compared to half sitting and bowing postures. Hence this simple device is recommended for harvesting saffron.

Plastic debris remaining in the field after harvest is one of the difficulties in farming under plastic mulch. In this study, the performance parameters of a domestic plastic remover machine in collecting plastic mulches were evaluated. The dependent factors were fuel consumption, plastic tearing frequency during collecting and the total collecting time. The independent factors included film thickness (two levels: 20 and 30 μm), ground speed (three levels: 2.7, 3.8 and 5.4 km/h) and the time interval between harvesting and plastic collecting (two levels: 5 and 10 days). The tests were performed in triplicate in a full factorial experimental design. Experiments were carried out in some farms of Fars province employing a two-wheel drive MF399 tractor. The results showed that using thick plastic (30 μm) reduces the plastic tearing frequency and hence with a lower number of stops, reduces the fuel consumption and increases the efficiency of the machine during plastic collection. To increase the efficiency of plastic collection, when using 30 μm plastic, the ground speed of 5.4 km/h is recommended. The best plastic collecting time with the minimum tearing frequency of are recommended as 5 and 10 days after harvesting for 20 and 30 μm plastics, respectively. According to the results the least fuel consumption was observed for collection of 30 μm plastic and with ground speed of 5.4 km/h. Also the simultaneous collection of drip irrigation tapes and plastic mulch tapes reduce costs and increase the efficiency of the plastic mulch remover.

Nowadays, the world is facing to increasing loss of fossil resources, energy crisis and environmental problems. On the other hand, diesel engines due to wide application in various sectors such as transport, agriculture, industry, etc., are the main sources of emissions and fuel consumption. Accurate measurement of fuel consumption and engine pollution is time-consuming and costly. Hence, the main objective of this study was to develop proper linear regression models of some important performance parameters of ITM285 tractor engine based on engine torque and engine speed. Experiments were carried out in 11 levels of primary engine speed (1063, 1204, 1346, 1488, 1629, 1771, 1818, 1913 and 2054 rpm) by 10 N.m steps of torque from zero (no load) to full load. The measured parameters include fuel consumption mass flow, exhaust temperature, instantaneous engine speed, maximum and mean exhaust opacities. Four different linear regression models were used to estimate the parameters. The results of regression models performance evaluation showed that quadratic model had the highest efficiency and the lowest RMSE for all parameters. The maximum and minimum effects of engine torque were on exhaust temperature and instantaneous engine speed, respectively; while, this result was completely reverse for primary engine speed. The results of regression models evaluation showed a high adaptation between the output of each model and the desired output. Also, the fuel mass flow and exhaust temperature were highly correlated to the maximum and mean exhaust opacity with correlation coefficients of 0.96 and 0.99, respectively.

With advanced equipment and development of software in the field of audio signals, it is now possible to record and register the sounds of tiny insects. Subsequently the acoustic features of the insects’ sounds can be extracted and then can be used for insect detection within the storage of bulk materials. One of the big challenge in receiving the audio signals emitted from the tiny insects is their low sound level. The designed audio system utilizes a piezoelectric acoustic sensor for receiving audio signals of the pest which is rice Sawtoothed (Oryzaephilus surinamensis) (Col. Silvanidae) along with a temperature control system. Two audio signals (walking and feeding) of Sawtoothed were captured by the sound system. The audio frequency of Sawtoothed for feeding and walking were 2.1 kHz and 2.8 kHz, respectively. By changing the ambient temperature, it is found that the best temperature range for the pest activity ranged between 25 °C to 27 °C. It was also observed that the pest activity is stopped at temperature below 10 °C. Such a system may be installed within the storages of bulk rice for early detection and other management decision making of the rice Sawtoothed.

Finite element method was used in order to model the simultaneous heat and mass transfer in cylindrical banana samples. The thermophysical properties of banana were considered as the function of moisture content and temperature. The simulation was carried out in the form of axisymmetric model. The Arbitrary Lagrangian-Eulerian (ALE) approach was used in order to incorporate the radial shrinkage effect in the model. The validation of the model was checked by comparing the predicted results with experimental data in various drying conditions. Results showed the mean relative error percent (E%) for estimating the moisture content and core temperature of banana samples in different drying conditions were in the range of 4.23-8.83% and 1.12-1.82% respectively. Therefore, the presented model was able to predict the average moisture content and core temperature satisfactorily. With considering the importance of estimating the moisture content and temperature, the model can be used as a confident tool in order to optimize drying process of banana from the quality and efficiency view. It is expected the presented model can be easily extended for drying of similar products with cylindrical shape.

In this study، ZnO nanoparicles and polymer nanocomposite were synthesized for film preparing of food packaging. The structural، physical and anti-microbial properties were then studied. ZnO nanoparticles were synthesized by sol- gel method. The Structural analysis by XRD verified the formation of zinc oxide phase. TEM images showed that the nanoparticles are spherical shape and their average size between 20 to 25nm. To prepare nanofilm، Zno nanoparticles were added at three concentration levels of 1،3 and 5%wt to the PVA matrix which prepared by solution processing method. SEM images of the film showed that in all samples the nanoparticles were distributed well in the polymer matrix. With using the Fourier Transmission Infrared (FTIR) at a wave length of 558cm- 1 Zn-0 band at all of nanoparticle concentrations were establish. The effect of inserting ZnO on the mechanical and antibacterial properties and moisture content of the PVA were also investigated. The increase of ZnO concentration in PVA from one to three percents causes the increase of tensile strength by 11%. The moisture content reduced up to 20%، when nanoparticles concentration increases from zero to five percents. Furthermore، by adding ZnO on PVA the antibacterial activity of the composite film was further improved.

Due to variation in economic value of different rice varieties, reports indicate the possibility of mixing different varieties on the market. Applying machine vision techniques to classify rice varieties is a method which can increase the accuracy of classification process in real world applications. In this study, several textural feature groups of rice grains’ images were examined to evaluate their efficacy in identification of three Iranian rice varieties (Tarom, Fajr, Shiroodi) in the mixed samples of these three varieties. On the whole, 666 images of rice grains (222 images of each variety) were acquired at a stable illumination condition and totally, 41 textural features were extracted from different matrices of grain images. Fisher's coefficient method, Principal Component Analysis method and a combination of these two methods were employed to rank and select the most significant features for the classification. The so called LVQ4 neural network classifier was employed for classification using top selected features. The classification accuracy of 97.96, 100 and 97.83 percent by using gray level matrix, 96.23, 100 and 100 percent by using co-occurrence matrix, 100, 97.50 and 100 percent by using local binary pattern matrix, and 100, 97.67 and 100 percent by using the whole textural features were obtained for Fajr, Tarom and Shiroodi, respectively. These results indicate that image processing can be a suitable tool for identification of different rice varieties. Although using the features of all matrices leads to less classification error, the features of each matrix also provides reasonable accuracy.