فهرست مطالب علی محمد برقعی

Drying is one of the most common methods of preserving agricultural products. It is very important to maintain the final quality of the product in the drying process. Changing the temperature parameter and humidity level of dryer air has a great impact on drying time and energy consumption. In this research, to compare the drying speed at different temperatures, a thermal dryer equipped with nano absorbent plates and closed air circulation and energy recovery was evaluated. So that the drying parts included: the product drying chamber, air communication pipes, air blowers, the chamber containing MOF nano absorbent materials, electric air heater and measurement and control systems. Experiments on mint leaves were compared at three temperature levels (40, 50 and 60 ºC) and in two open and closed air circulation methods. The results of the research showed that the drying time decreased with the increase in temperature and the drying time decreased by 50% under the conditions of using nano absorbent plates. Also, the lowest energy consumption was obtained in the conditions of using nano-absorbers at the rate of 161.92 W/h equal to 49% in reducing energy consumption. The changes in the total color index (ΔE) did not change much with the increase in temperature from 40 to 50 ºC, but from 50 to 60 ºC, the total color From 9.22 to 12.86 index increased, but there was not an obvious difference in the total color index between the two methods of using and not using nano absorbents.

This study evaluated the performance of a thermal dryer with a closed air circulation system equipped with a metal-organic framework (MOF) system. Dryer sections included: product drying chamber, the MOF containing chamber nano-absorbents, measurement and control systems. Dryer yield on mint was compared at three temperature levels (40, 50, and 60 °C). Finally, the energy consumption and drying mint leaves was evaluated. The results showed that the closed air circulation system reduces the dry time by 27% to 50%, the penetration coefficient of mint leaves increased with increasing temperature. Its values in cases of not using and using nano-absorbent plates were determined respectively (4.05690×10-11) and (2.8215×10-10) m2/s. The activation energy in two methods of not using and using the nano-absorbents was 45.72 and 51.96 kJ/mol, respectively, which is consistent with the researchers' results. Also, the coefficient of performance, the rate of moisture evaporation, and the rate of specific moisture evaporation showed the effectiveness of using nano-absorbent in the dryer system and reducing energy consumption. The total color index (ΔE) did not change much with increasing temperature from 40 to 50 °C, but from 50 to 60 °C, the increased total color index. There wasn't a clear difference in total color index between the two methods of using and not using nano-adsorbent.

In this research , The kinetics of drying , The Determining The effective Moisture Diffusivity, Activation Energy, And also the prediction of the moisture ratio of red onion during the dry process with dryer-hot air drying were carried out with the help of mathematical models and fuzzy neural inference system (ANFIS). The experiments were performed at four levels of temperature at 50, 60, 70 and 80 0C and a constant air flow rate of 1 m/s . To select a suitable drying model, twelve thin layer drying models were used, as well as using fuzzy neural inference system R Software version 3.6.2. The results showed that among the mathematical models, The binomial model with the highest coefficient of explanation and the lowest root mean square error was the most suitable. The results of the correlation coefficient value (R2 = 0.999 and error) RMSE = ( 0.002) the lowest root mean square error It predicted the humidity ratio better than mathematical models. Effective Moisture Diffusivity for four temperatures, Respectively (0.03136255,0 0211698,00193770.001847669 0) M2/ S and The amount of activation energy was 1890.4 (kJ /(kg.K).

Providing new solutions to control wet waste is one of the most important issues in maintaining public health. Drying will reduce the harmful effects on the environment by reducing moisture and the smell of wastes as well as easy transportation and disposal costs. The purpose of the design and development of the household dryer is to dry food waste in order to reduce its volume and prevent the spread of its pollution in the air, water, and soil. To study the drying behavior of food waste, an experimental cabinet dryer was designed, fabricated, and evaluated for drying food waste.

The dryer consisted mainly of the drying chamber, electric heater, fan, air inlet channel, mesh tray, air distribution plates, temperature sensor, and control panel. Different parts of the dryer were made of a stainless galvanized sheet. The dryer was modeled using Catia 2019 software and its various parts were designed. The heating power was calculated as 2.7 kW. A centrifugal fan with an air volume of 310 m3h-1, 2800 rpm, and 110 Pa was used to supply airflow in the dryer. In the drying process, a tray with medium and lateral air passage was fabricated and applied. Food waste was obtained from fruit and vegetable waste, homemade food, and fruit shops. And nonfood items such as glass, paper, plastics, and metals were separated from the waste and crushed with a shredder, and reduced to sizes less than 20 mm. First, the product was placed in the environment for one hour and then pressed with a mechanical press with the same pressure to eliminate part of the water. An anemometer UT363 model made in China was used to measure the air velocity. The temperature was measured and controlled by a temperature thermostat of G-sense model made in Iran. The effect of three temperatures of 50, 60, and 70 °C and three inlet velocities of 1, 1.5, and 2 m s-1 on the kinetics and intensity of drying of food waste and energy consumption of food waste with a thickness of 3 cm was investigated. Moisture ratio and drying intensity diagrams were extracted. Diffusion, activation energy, and energy consumption were determined.

Drying kinetics diagrams showed that temperature had a significant effect on moisture variation of food waste during drying. Drying period decreased with increasing temperature. The slope of the drying intensity diagrams increased with the increase of the dryer temperature. Drying rate was decreased at the temperature of 70 °c and it had a steeper slope that indicates the more intensity of the drying process in this condition. The drying process of all three samples occurred in the falling rate stage. The air duct on the side and in the middle of the tray caused hot air conducted above the tray and increased energy consumption. Effective moisture diffusivity of food waste during the drying process was in the range of 3.65×10-9-4.56×10-9 (m2 s-1). The effective moisture diffusivity at temperatures of 50 °C and 60 °C was less than 70 °C. Because at the temperature of 70 °C, the membrane resistance of the cell destroyed by high heat and increased the diffusion coefficient in the material.

Increasing temperature caused the drying period decreased and the drying occurred in the falling rate stage. Temperature and the interaction of velocity and temperature had a significant effect on the drying process. The highest drying intensity and the lowest drying time were observed at the temperature of 70 °C and a velocity of 2 m s-1. Energy consumption had the maximum value at the temperature of 70 °C and a velocity of 2 m s-1 and a minimum value at the temperature of 50 °C and a velocity of 1 ms-1. The amount of activation energy for the food waste mass at three velocities was equal to 10417.44 J mol-1.

The use of machines in the process of agricultural production is aimed at to reduce the production costs, timely performing the agricultural operations, reducing the labor costs, managing inputs, which ultimately resulted in productivity improvements and a quantitative and qualitative increase in production. The purpose of this study was to investigate the mechanization status of agricultural and horticultural products in Iran which by studying different systems of utilization of agricultural machines, studying the problems in agricultural mechanization of Iran can provide suggestions for promotion of agricultural mechanization in Iran with emphasizing sustainable agriculture and pay attention to the environmental impacts of agricultural mechanization. In order to measure the mechanization indices, the distribution of crop cultivars were extracted from the data between 2014-2015. Also, in order to measure the mechanization index in different sectors between 2013-2017, data were collected from Ministry of Agriculture Jihad. The results of the study showed that the status of mechanization coefficient as an indicator for showing the mechanization status in the country's manufacturing cooperatives is not suitable. The role of mechanization in increasing the production of agricultural and horticultural products was about 35% due to the presence of machinery in the production process. The results showed that the sustainable agriculture can be achieved with mechanization in such a way that the least harmful impact on the environment is reached. Energy indicators are one of the most important tools for assessing energy consumption in this sector.

Robots are suitable for doing things that are tedious, difficult or dangerous to humans. One of the recent applications of robots is to perform various operations in the agricultural sector. The limitations in human resources and the demand for higher efficiency per unit area has made it necessary to use robots in agriculture. In the study, a robot spraying manipulator based on the Stewart mechanism was designed and constructed to perform spraying operations inside the greenhouse with the help of a manual end effector (mechanical robotic arm). In general, manually applied spraying does not spread evenly on all plants, resulting in increased toxic waste, there are also spraying labor costs in this method, so it is not economically viable. Hand spraying is a problem caused by direct contact with the toxin, which puts people in direct contact with chemicals at greater risk for a variety of diseases. Therefore, most of the toxic chemicals used to overcome weeds are a threat to humans and the environment. By poisoning the skin, mouth or breathing can be highly toxic. The end effector sprayer is based on Stewart's mechanism and by using six degrees of freedom, allowing nozzles to spray at different angles on plants. For this purpose, six step motors were used to provide the rotational force of the operator's end effectors, which was launched with the Arduino system. In order to supply electrical energy, operator's end effectors and Arduino devices utilized a 500-watt computer power supply, calculating the dynamics and reverse kinematics of the Stewart platform, we specified unique codes for its rotation. In this study, inverse kinematics was used to obtain the position of the joints by knowing the position of the center the moving platform and connecting the connectors to the moving platform by the hinge joints, and to the actuators arm by the spherical joint. The dynamics of the actuator, the movement of the moving platform by the actuators was calculated. In this method, the direction of the moving platform the step motors are driven a time by the microcontroller in pairwise manner. Using arms and linkers, stepper motors could move the platform in three different angles. Due to the angle and radius of the arm's, the moving platform has an angle of 18 degrees to the horizon, which makes it able to spray directly into the target plant and make a same coating. Also the velocity and acceleration of the moving platform movement were calculated according to the rotational speed of the stepper motors the maximum velocity and linear acceleration of the moving platform are calculated 141 mm / s and 244mm/s2 respectively. In order to accurately evaluate the performance of the sprayer, laboratory experiments were carried out to verify the performance of the control system and determine the height of spraying at different intervals. The end effector nozzle height was 117 cm above the ground, and the moving platform end effector with zero degree angle, and 18 degree spraying. It was determined that at a distance of 0.5 m 1 m and 1.5 m from the nozzle, the spraying heights were 100 cm, 57.7 cm and 12 cm accordingly. Based on this evaluation, spraying operation which was carried out at a distance of 0.5 m from the nozzle could reach highest level of spraying height. Finally, after modeling the end effector with solidworks software, it was simulated in the Adams software environment and by transferring the model to Adams, the force applied to the moving platform by the actuators, the velocity and acceleration of the moving platform were investigated. In the simulation, the applied force was evaluated by a pair of actuators on the moving platform, with the software output predicting the applied force correctly. In examining the linear velocity of the moving platform, the software output was about 5 cm/s more than the actual value and also in the simulation of linear platform moving acceleration, the software output was equal to the calculated value. According to studies, this is the first time that the platform has been used in robotic sprinklers, and could be a reference for further research in the field due to its innovation. This end effector had no singularity at an angle of 0 to 18 degrees and in both directions, spraying had a 10% difference in spraying. According to the simulation results performed with Adams software, the amount of force applied by the propellers was linear on the moving platform. Moreover, according to the simulation results with the aforementioned software, the acceleration changes of the moving platform were also linear.

Three electrode system simulates the human tongue taste system and can be used to assess the quality of food. The sense of taste is one of the five senses and tongue recognizes certain molecules. In recent years, three electrode system with an array of electrodes has been used to identify various molecules. In this research, a three electrode system is used based on voltammetric methods with three graphite electrodes (Pencil Graphite (PG)), Screen Printed (SP) and Glassy Carbon (GC) to identify heavy metals (cadmium , Lead, tin and nickel) in olive oil. Heavy metals are added to the edible oil in three concentrations of 0.05, 0.1 and 0.25 ppm and then the output of the device is classified by chemometric method. According to PCA results, the PG electrode contains 96% of the variance between the data in olive edible oils. Also, SP electrode contains 91% and GC contains 100% of the variance between the data in olive oil. The SVM method showed a high ability to classify heavy metals in edible oils. Also, The PLS method was also able to predict 99% of the data in olive oil for all electrodes. Finally, according to the results, it can be said that the built-in three electrode system has a high accuracy in identifying heavy metals in edible oils.

One of the main factors affecting plant growth is soil compaction. More attention should be paid to soil compaction than the past. Soil compaction not only destroys the soil structure, but also leads to a heavier soil structure with natural cavities. The rolling resistance reduces energy and occurs when the tire moves on a soft soil and rolling resistance of the tire is brought about by two processes of soil deformation and wheel change. This force is influenced by the design of the tire, the parameters of the tire, and the characteristics of the soil. The apparent electrical conductivity (ECa) indicates the direct conductivity of direct current in the soil. The electrical conductivity is effective on chemical and physical properties, including the amount of soluble salts in the soil, salinity, cation exchange capacity, soil texture, organic matter content, moisture content and water holding capacity, and compression. The purpose of this study was to investigate the effect of soil compaction and soil moisture on the soil electrical conductivity and rolling resistance of the Messy Ferguson 285 tractor rear tire. This study showed the density and soil moisture were associated with soil electrical conductivity and rolling resistance.

This test had independent and dependent variables. The dependent variables including rolling resistance and electrical conductivity, whose values were measured by a torque meter and a portable EC meter. Independent variable comprised of soil compaction and soil moisture measured by Penetrologger and soil moisture measurement tools including soil harvesting cylinder, scale and oven device. Experiments were carried out in the soil bin Laboratory with a 1.7 m wide, 24 m long and 1 m deep with soil texture of clay loamy in Agricultural Engineering Research Institute (Karaj). The soil was prepared layer by layer and up to a depth of 20 cm by the soil preparation unit. In all experiments, the vertical load was fixed at 4000 N and the tire pressure of 6899 N.m-2. On each layer, the water was evenly sprayed to reach the desired moisture. To do this research, factorial experiment with soil compaction levels at 3 levels of 2, 4 and 6 roller passes, respectively, with the bulk density of 1.47, 1.54 and 1.69 g.cm-3 and soil moisture at 3 levels of 10%, 12% and 14% were used in 3 replications. Data were analyzed using SPSS software. The tools used included the tire test rig, the rear tire of a Massy Ferguson 285 tractor, the soil preparation unit, and the measuring instrument, including the torque meter, the penetrologger and the portable EC meter.

In this experiment, it was found that as the amount of moisture increased, the compaction was also increased. The test indicated that the soil rolling resistance was increased by decreasing the soil moisture content. Moreover, increasing in the soil compaction ration led to decreasing the soil rolling resistance. The CI was used at a depth of 20 cm to 0 cm. In these experiments, we concluded that the higher density of compaction resulted in increasing the soil cone index (CI). This index was directly related to the compaction, but it had an adverse relation with the moisture. It means the lower amount of moisture led to the higher amount of CI. The amount of electrical conductivity of soil was measured at a depth of 0-25 cm. In this experiment, we concluded that the higher compaction ratio resulted in the higher electrical conductivity. It means that electrical conductivity had a direct relation with the compaction and the moisture content. The lower moisture content led to the lower electrical conductivity of the soil.

In general, considering all the tests and comparison between rolling resistance, soil cone index and apparent electrical conductivity before and after roller passing, it can be concluded that as the amount of moisture content increased, the soil cone index (CI) decreased. The soil cone index (CI) had a relationship with the moisture. The lower moisture content led to the lower soil moisture resistance, as well as the higher moisture content resulted in the higher soil resistance. The lower amount of soil compaction showed the greater soil rolling resistance, and the greater amount of soil compaction caused to the less soil moisture resistance. The electrical conductivity before and after the roller pass was different in the case of roller pass, and the higher amount of moisture led to the greater electrical conductivity, because the electrical conductivity was directly related to the moisture and the compaction affects all parameters.

Study on biometric parameters of trout species in the traditional method (based on human and non-automatic factors) are low-efficient due to serious problems such as disease transmission, stress-induced death, inaccuracy, & time-consuming. To overcome the problems of traditional method, an image-based vision system, including imaging and lighting chambers, was developed in this research. The fish biometric parameters were measured using fish movement videography during passage from the dark chamber. Then the selected images from the video were processed. The length, surface area, weight, amount of food consumed, & growth rate of trout were measured under fully controlled conditions and used as comparison criteria (control). Six mathematical models were used to estimate fish weight through measured parameters and among them the weight/length model was used as the best model for estimating fish weight. The accuracy of the system in estimating fish biometric parameters was above than 90% and the system’s capability to estimate the fish required food during the growth process was 98%.

Measuring the efficiency of operating systems in comparison with the methods of comparing the performance of systems explains the various dimensions of issues such as, the lack of full use of agricultural machinery capacity, improper selection of machine, incorrect use of machinery, ownership, etc.. Any improvement in operating system conditions reduces costs,, consumption of inputs, increases the efficiency of production factors and consequently reduces the price and increases agricultural profitability. The main objective of this research is to compare the operational-management efficiency of operating systems in Alborz province and comparison of managerial and operational efficiency of agricultural machinery farming systems by calculating the efficiency of its major components in agricultural machinery farming systems including efficiency, social, economic, technical-operational and managerial and ranking them in order to understand the optimal model of agricultural machinery systems.
This research is a survey study.The study population was beneficiaries of agricultural machinery in the Alborz province which in the multi-stage random sample was determined. Alborz province has 31,438 agricultural operations, of which 543 are exploited agricultural machinery. Cochran formula was used to determine sample size. Since, Cronbach's alpha coefficient greater than 0.7 was obtained by questionnaire, the reliability of the questionnaires was assessed as desirable. To calculate the efficiency the component data were extracted from 4 specialized questionnaires after the initial examination and encoding, then they were analyzed using the software SPSS, MCDM Engine. TOPSIS techniques were used for ranking managerial performance operating system for operating agricultural machinery Alborz province.
The results showed that social efficiency of dedicated-professional operation with an average of 6.6 had maximum efficiency operation among the three systems of agricultural machinery. Economic efficiency of professional operation system with an average of more than 1.43 units is capable of the highest rate among the three systems and economic performance of the dedicated operation less than one and equal to 0.76 in the three systems have the lowest rate. In other words, the professional operation of the annual profit is 43%, but the annual dedicated operation is facing a 24 percent loss. Performance of management operation system is dedicated 6.19 and was the highest performance among systems. The number of dedicated- operation system 5.42 is the least efficient management of three farming system agricultural machinery in Alborz province. Appear organizing, planning, directing and coordinating, decision-making, control and supervision of the operation system was far better than the other two systems. The operating efficiency of the dedicated operating system is 76.537% and in this respect, it has the highest value among the three operating systems and the lowest operational efficiency is related to the professional operating system.
The increased operational efficiency of the dedicated operating system is further influenced by the high average scores for the indicators of timely operations, the availability of the machine and the quality of the operation. Kruskal-Wallis statistical tests were performed to compare the average of four types of efficiency (social, economic, managerial, technical-operational) in three agricultural machinery farming systems, with mean difference for all items at 5% and 1% significance.
Ranking of managerial-operational efficiency of agricultural machinery utilization systems using TOPSIS technique: The ranking criterion of this technique is a similarity index, with a range of 0 to 1 variation. The results showed that among the three systems of agricultural machinery exploitation, the professional farming system with the rank of 0.9219 ranked first, the professional- dedicated farming system with 0.5261 had second rank and dedicated farming system with 0.1556 ranked third
The results showed that the managerial-operational efficiency of the professional operating system was more than the other two operating systems, which was due to the high effectiveness of the management-operation of the economic efficiency and technical-operational efficiency, which in this system was more efficient from other systems. Investigating the importance of factors affecting the efficiency of agricultural machinery farming systems showed that the weight economic factors is far more than other factors and the effect of economic efficiency on the efficiency of the entire farming systems is much higher. The cost of ownership of a machine is very important among economic agents, this factor directly affects the choice of operating systems, and it also indirectly affects other factors. Therefore, it can be concluded that the key for improving agricultural machinery management and increasing the productivity of this important input is to perpend different aspects of the cost of ownership.

Thermal processing has a huge impact on the textural attribute of the final food product and texture is a major factor contributing the overall quality of food. Ohmic heating is an advanced thermal processing method in which heat is internally generated within foods by passing an alternating electric current through them. Ohmic heating can volumetrically heat the entire mass of a food system, resulting in faster heating, better quality and less energy consumption than conventional thermal processing. Gradient voltage and electrode type have high effect on ohmic heating system.
In this study, the effect of voltage gradient and electrode type on moisture reduction time, a/b, ΔE color indexes and energy consumption were studied. For this purpose, four levels of voltage gradients (5, 7, 9 and 11 V cm-1) and four electrode types (Aluminum, Stainless steel, Brass and Graphite) was investigated by ohmic heating in tomato paste processing. Tomato used in this study was purchased from a local market. The whole tomatoes were washed, crushed and mixed in a way that a red less-viscous liquid obtained (Fig. 1). This liquid was considered as tomato samples in the remainder of the article. Ohmic cooking experiments were conducted in laboratory scale ohmic heating system consists of a power supply, a variable transformer, power analyzer, a microcomputer, digital scale (GF-6000) and thermometer (Dual inpur RTD 804U) (Fig. 3). The ohmic cell had a PTF cylinder with an inner diameter of 0.05 m, a length of 0.10 m and two electrodes on both side of the cell. A hole with 3 mm diameter to insert the thermocouple was created and two holes with 5 mm diameter was created on surface of cell. One of them was used for pouring tomato puree and other for exiting steam from cell.
Temperature uniformity was checked during previous heating experiments by measuring the temperatures at different locations in the test cell. Ohmic heating was accomplished till the moisture content of the tomato samples reduced from initial moisture content of as 91(wet basis) to a safer level of 70 (wet basis). Moisture reduction time, a/b and ΔE color indexes, temperature and energy consumption were measured.
The results of the nonlinear mathematical model showed that the effect of different voltage gradient levels on moisture reduction time, ΔE parameters and energy consumption had a good agreement (α≤0.01) as well as voltage gradient had a significant effect on a/b color index (α≤0.05). Electrode type had significant effect on processing time, ΔE (α≤0.01), on energy consumption and a/b index (α≤0.05). Interaction of voltage gradient and electrode type was significant on processing time, energy consumption, a/b and ΔE (α≤0.05). In all electrodes by increasing the voltage gradient, processing time and energy consumption were reduced. For example by increasing the voltage gradient from 5 to 11 V cm-1, processing time and energy consumption were decreased on average 38% and 23%, respectively. Minimal processing time and minimal energy consumption were observed in 11 V cm-1 with graphite electrode that were 17 min and 203 kJ, respectively. As well as maximum processing time and maximum energy consumption were obtained in 5V cm-1 with aluminum electrode that were 105.21 min and 321 kJ, respectively. But maximum a/b parameter and minimal ΔE index were observed with stainless steel electrode in 11V cm-1. In determining the best electrode, in addition to the processing time and energy consumption, product quality is also an important parameter. However, graphite electrode has better performance in terms of time and energy consumption, but stainless steel electrode has better performance in term of product quality. Since the production of food, quality is an important parameter, and also the two electrodes graphite and steel are similar in terms of energy consumption and processing time, but stainless steel electrode is better in term of quality, so stainless steel electrode is selected for ohmic heating tomato paste.
Different voltage gradients and Electrode type have a significant effect on processing time, energy consumption, ΔE and a/b color indexes. Minimal processing time and minimal energy consumption were observed in 11 V cm-1 with graphite electrode that were 17 min and 203 kJ, respectively. But maximum a/b parameter and minimal ΔE index were observed with stainless steel electrode in 11V cm-1. Stainless steel electrode and 11 V cm-1 voltage gradient were the best condition for tomato paste processing by ohmic heating.

Nitrogen is an effective material for improving the crop production and cow manure is an important resource for soil fertilization and improving physical condition of soil. However there are many factors that limit the application of ordinary composted manure. These problems are low density of manure, different nutrient requirement of the crop and rapidly nitrification. The effective solution of these problems is densification technology with molding manure compost into pellet and adjusting the nutrient content of material with adding nitrogen fertilizer. In this research the pelleting machine is used to make dry composted manure into pellets (diameter 10mm and length 50mm) with adding chemical fertilizer and binder material (bentonit) physical properties of pellets determined within moisture content range 11% and 24% (w.b.) and sorption property of pellets were researched. This study therefore focused on evaluation of effect of pelleting process on decreasing of nitrification. Results obtained showed that hardness and durability of pellets increased with decrease in moisture content and increase in applied force. Also, effects of mentioned factors on true density, bulk density and porosity were observed. The effects of slow-release from mixed pellets in basil crop yield were also observed. Pellet fertilizer is a type of slow-release N-fertilizer that slow-release N-fertilizer has long-term effects including reduced leachinglosses and enhanced N uptake, as well as. positive effects on both health and soil nutrient levels.

The use of Bio-ethanol as an alternative diesel engine fuel is rapidly increasing. Bio-ethanol is mixed with diesel fuel at different ratios and used in CI and SI engines. Since vibrations have direct effects on users and engine components، for this reason analysis of vibration resulting from combustion in CI engines is very important. In this study، evaluation of vibration was performed for both diesel and ethanol blends. Commercial diesel fuel (D100)، E2 (2% ethanol and 98% diesel fuel)، E5، E10، E15 and E20 were used in a two-wheel MITSUBISHI tractor. The engine was tested in 1200، 1600، 2000 and 2400 rpm for all fuel blends، and also the effect of load was investigated for D100 and E10. Results showed that vibration is significantly affected by fuel blend. It was observed that E10 had the lowest vibration while E20 had the highest value. It was also observed that vibration increased as engine speed increased for all fuel blends. It was found that both axial and lateral vibrations affected significantly by load. The lateral vibrations decreased continuously with load rise، but the axial vibrations increased initially but started to follow a reverse trend.

Agricultural mechanization is a method for transiting from traditional agriculture towards industrial and sustainable one. Due to the limitation of natural resources and increasing population we need to have economical production of agricultural crops. For reaching this destination; agricultural mechanization has a remarkable role. So it is necessary to have an extensive view for mechanization، because with the help of mechanization the agricultural inputs such as seeds، fertilizer and even water and soil can effectively be managed for an economical and sustainable production. This study has been carried out in many provinces of Iran. The data of agricultural tractors and cereal combine harvesters were firstly gathered by means of questionnaire. The tractors were categorized in four power levels of less than 45، 45 to 80، 80 to 110، and more than 110 hp. In addition، it was also carried out for cereal combine harvesters; it was in three power levels، i. e. between 100 to 110، 110 to 155 and 155 to 210 horse-power in 3 ages، i. e. less than 13، between 13 to 20، and more than 20 years. Information regarding to cultivation areas، production volume، and yield of main crops gathered from statistics of Ministry of Jihad-e-Agriculture. Then agriculture mechanization level index (hp ha-1) in each province was calculated. Four main crops including irrigated and rain-fed wheat and irrigated and rain-fed barley، which met the required criteria to be used in the model، were statistically analyzed. Correlation analysis was carried out in order to get an effective model between yield of the four main crops in Iran and agriculture mechanization level index. Pearson correlation index showed that there is a direct and significant correlation between these variables. Subsequently، outliers were identified in order to get a model with necessary efficiency to predict the yield through mechanization level index، by scatter diagram and estimating regression lines in 1% probability level. The effective model was estimated with acceptable coefficient of determination 0. 851، after removing outliers.

In this research، four different positioning methods were compared in order to evaluate their accuracy، using a remotely controlled robot on a specific route. These methods included: using a single GPS module، combining the data from three GPS modules، using an Inertial Measurement Unit (IMU)، and GPS/IMU data fusion. The comparison of these four methods showed that GPS/IMU data fusion along with a Kalman filter was the most precise method، having a root mean square error of 23. 4cm. Integrating the data acquired simultaneously from three GPS modules with fixed and equally spaced position and far enough from each other، had a root mean square error of 31. 3cm was the second most precise method.. Also analysis of the IMU data showed that due to cumulative errors، it was not a suitable method using a single IMU for positioning.

The most important quality indicator of fruits is the flesh firmness which is well correlated to their young’s modulus. In this research variation of vibration characteristics (shape modes, natural frequency) of apple due to change of material characteristics (density, young's models, Poisson ratio) and apple volume was investigated using Finite Element simulation. An image processing technique was used to obtain an unsymmetrical and non-spherical geometric model of apple. The exact three-dimensional shape of the fruit was created by determining the coordinates of apple surface and forming uneven rotational curvatures. Modal analysis with no boundary constraints has been applied. The first 20 Eigen frequencies and the corresponding mode shape were determined. Six rigid body modes possess zero resonant frequency which is related to the degree of freedom of a rigid body in space indicated the validity of finite element model. The modal analysis results showed that resonant frequency increased by increasing young's modulus of the fruit, while it decreased by increasing apple density. First mode torsion has a mean resonant frequency of 584 Hz. Variations of natural frequency due to change in young's modulus, density, and Poisson ratio were 80%, 11% and 4%, respectively. Coefficient of variation of resonant frequency in response to changing young's modulus was 2-3 times of that of density which shows the greatest effect of young modulus changes on natural frequency of fruits. Consequently with determination of fruit's natural frequency, their young modulus and firmness can be estimated.

Agricultural mechanization goal is to maximize the utility. Establishment of subsidies systemization and Iran incorporation with World Target Organization (WTO), choosing an appropriate technology will be more important. Agricultural development is due to correct mechanization and choosing an appropriate tractor is one of mechanization implementation bases. In the paper, criteria involved in choosing an appropriate tractor were considered according to Hamedan province conditions and the best choice between 11 tractor models was selected regarding to 9 criteria which were analyzed by Technique for Order-Preference by Similarity to Ideal Solution (TOPSIS). The criteria are: drawbar power, hydraulic power, power take off (PTO) power, PTO shaft, specific fuel consumption (SFC), speed range, engine standard round per minute, gearbox, and manufacturer. Between the choices, U453 was preferred and recommended as appropriate tractor.

Performances of electronic and mechanical draft control systems on a MF399 tractor were the objectives of the study to be evaluated and compared under field conditions. Hence, the effects of two draft control systems (mechanical and electronic) under four ground speed levels and three set values of draft levels on rear wheel slippage, fuel consumption, compressive force within the top link and tillage depth in a sandy loam soil were assessed by conducting an experiment of a randomized complete block design. Results obtained from the statistical analysis revealed that there was a significant decrease in mean values of slippage as well as in fuel consumption when the system equipped with electronic control as compared with the mechanical one. It was found that the compressive force within the top link as well as mean depth value were significantly lower with the electronic control system resulting in a decrease in wheel slip as well as in fuel consumption. The results also revealed that fuel consumption decreased with increasing ground speed and decreasing the set values of draft. The mean value of slippage in electronic control system for all the treatments was recorded less than 20%, while with the mechanical system it reached level as high as 39%.

Since Iran is a windy country due to the adjacency to the sea and the existence of Alborz and Zagros plateau, it is expected that the use of wind energy will be developed in near future. The present study aimed at finding the best blade Angle and the best location maximum camber from the chord from among selective levels. Determining the above levels can lead to an increase in few-bladed wind turbines. At first, models of wind turbines, each with thickness from chord and camber was made in. These models were put in wind production mechanism. All data from experiment were statistically analyzed by software & software and test. The results showed a significant difference between power from the experiment in different wind speeds and location maximum camber. From Duncan test, it was found out that in wind turbines among five levels of angle of attack, angle with an average power of watt, and among levels of maximum camber level of with an average power of watt and among three levels of wind speed, level of with an average power watt produced the largest among of power from among selective levels. Also it was found out that interaction between variables (angle of attack, location maximum camber and speed) was significant and the model with an angle of attack of, location maximum camber of and wind speed of was presented with power of watt as the best model for the largest amount of power.

In order to study the effect of agronomic research findings on increasing grain yield in farmer fields, a study was carried out in 150 farmers’ fields in East Azarbaijanin in 2004-2005 cropping season. Fields in Maragheh, Mianeh, Hashtrood, Charoimagh, Sarab and Ahar regions were surveyed. There were 77 questions related to the crop planting, soil fertility management and harvesting and 14 questions were designed for recommended research findings. Farmers’ answers were collected. These data were analyzed by SPSS software using t- test and stepwise regression analysis. The results indicated that differences between application of recommended research findings by Dryland Agriculture Research Institute)DARI) with common farmer management practices, except using fertilizers, were significant (P<0.01). In addition, regression analysis showed that fertilizer placement, stubble management, date of planting, depth of planting, secondary tillage system and fertilizer significantly increased grain yield. The differences in grain yield were 20.69, 16.44, 18.18, 16.61, 13.17, and 9.99 percent, respectively. It can be concluded that application of research findings by farmers through technology transfer procedures can increase dryland bread wheat grain yield.

Costs of repair and maintenance are most part of the cost of machinery usage. Cost estimation of repair and maintenance of agricultural machinery is very important for replacement and net return of management of machinery. This is an important factor to present a mathematical model for the cost predication of repair and maintenance. The main goal of research was to present a mathematical model of repair and maintenance cost modern tractors in selected province of Iran. In this case New Holland TM155 and Valtra 8400 tractors were selected in Markazi and Fars provinces. First of all a questionnaire including driver's information and technical data for the tractors was completed by randomly sampled tractor driver. In this case 100 questionnaires were distributed between users of each type of considered tractors during spring till summer of 2007. Provided data were analyzed by SPSS and Excel soft wares to do statistical analysis and determining appropriate mathematical models. T test was used to mean comparison of tractor’s cost and Z, F and R2 as statistical test and indexes were done to finding appropriate mathematical models. The average annual repair and maintenance costs of New Holland TM155 and Valtra 8400 were calculated 3304 and 3635 Ri/hr respectively. Results showed that the average repair and maintenance costs of Valtra 8400 were significantly higher than New Holland TM155 tractors at 5% confidence level. In this research appropriate mathematical models were offer to estimate repair and maintenance costs of each models.