فهرست مطالب محمد جواد شیخ داوودی

Sugarcane is one of the most important industrial plants in Khuzestan province. With the rising costs of purchasing, maintaining, agricultural machinery, sugarcane agribusinesses have been adopting outsourcing strategies in various sectors, especially in agricultural operations, over the last few years. Considering the importance of three criteria: cost, timely performance and quality in agricultural operations, these three criteria were evaluated in the work of contractor and company labor force in preparation in Amirkabir and Debal Khazaei agribusinesses. To investigate costs, cost information was obtained from the companies studied. The quality of operations was evaluated by field data collection and measurement of qualitative indices. Also, to check the timing of operations, the agricultural operations calendar was compared with actual days of work. Finally, the indices tested (in outsourced and non-outsourced farms) were compared using t-test for independent samples. The most important criterion for land acquisition operations in the agribusiness companies studied is the quality of operations. The results of the comparisons also showed that there is no significant difference between the cost and time of the contractor and corporate force operations but in terms of quality, which is the most important criterion for agribusinesses, contractor workforce outweighs corporate workforce. Therefore, outsourcing operations are for the benefit of the studied companies.

Production and use of biogas, as an alternative renewable fuel, along with increasing energy security, can reduce the use of fossil fuels and thus reduce the environmental impact of these fossil fuels. Biogas production is subject to certain conditions and is influenced by some parameters such as pH, Hydraulic Retention Time (HRT), Solid Retention Time (SRT), temperature, agitation and so on. The existence of a laboratory digester to control and identify the best conditions of these effective parameters is of great importance. Therefore, three types of anaerobic digester, were built to digest liquid wastes, considering the advantages and disadvantages of various digesters, factors affecting biogas production and also considering the cost issues. In these digesters, it was possible to control the parameters affecting biogas production (temperature, pH, concentration and retention time) and were also equipped with a system to measure the amount of gas produced. These digests were batch type and the feasibility of experimental designs to study the effect of parameters affecting biogas production was predicted. Batch digests are more suitable than continuous ones to study raw materials that require longer retention time, such as lignocellulosic biomass. Due to the transparent body of these digesters, it was also possible to study optical treatments. The most important and difficult part of the construction was the possibility of sealing the joints. Glass digester, if properly sealed, is the best one and meets almost all requirements for testing the factors affecting biogas production. Its main problem is the possibility of air leakage and liquid penetration into the mixer electromotor. Due to the flexibility of polyethylene digesters, it is easy to extract air and provide an anaerobic environment. The disadvantage was the requirement of manual or magnetic mixing and a possible error in measuring the volume of gas produced. Use of the Erlen vacuum, rubber cap, needle and heparin locker were appropriately meet the requirements of an anaerobic digester, but steel mixing in the digester is done manually or by magnetic stirring.

Assessment of land suitability is one of the basic approaches to maximizing profits and protecting environmental resources. The purpose of this study was to determine the land suitability of Ahwaz county for cultivation of irrigated wheat using AHP Method and GIS. Ecological factors, agricultural factors and other parameters affecting wheat cultivation in Ahwaz county were determined. Soil permeability, soil texture, EC, pH, slope, accessibility to main roads and markets, and net income were selected. Data were collected by questionnaires distributed among farmers, experts, and government organizations. The results showed that economic criteria and soil characteristics had the highest weight, so that net income with the weight of 0.316 was ranked first. It has been found that average net income and benefit/cost ratio were 10.2 million rials per hectare and 0.44, respectively. The highest cost in wheat production was observed in machinery and equipment. Based on integration of GIS layers and assessment of land suitability, it was found that of total land area, 11.1% was very suitable, 32.5% was suitable, 30.4% was moderate, and 26% was unsuitable for wheat cultivation.

Sugarcane is an important industrial -agricultural crop in country. Considering the high cultivation level of this product in Khuzestan province and the high volume of data stored in these mechanized agricultural units, it is necessary to have a tool to process stored data. The data mining technique is well equipped to provide sugarcane manufacturers with the necessary information and patterns in modeling the yield of sugarcane. One of the most practical of these algorithms is decision trees. The main objective of this research is to predict yield sugarcane and to evaluate the factors affecting it using decision trees CART and CHAID. The present work was an analytical study conducted on a database containing 13211 records. Data were obtained from farms of Amir Kabir Agro-Industry, during 2013-2016. Data analysis was performed using IBM modeler software version 14.2 by CRISP methodology. The accuracy of decision tree (CART and CHAID) on the training data and test data were 90, 81, 85 and 79 percent, respectively. The results of this research can be used for sugarcane production and cultivation industries in Khuzestan Province in order to evaluate and optimize the sugarcane production process and predict the yield of sugarcane.

The aim of this study was to design, Constructand evaluate an electronic system for control of the forward speed control in 7000 series sugarcane harvesters. The conventional method of control for the forward speed of sugarcane harvester in 7000 series is mechanical. The new electronic control system was developed to replace the traditional mechanical control system. MotorStepper, drivers, micro-controller, joystick and potentiometer were used to program microcontrollers as well as C programming in code-vision. The new control system was evaluated during two series of tests. To determine the strength of the maneuverability of the harvesting machine, the first test was conducted using a factorial experiment based on completely randomized design. The maneuverability was compared for mechanical and electronic control systems under different engine rpm. The location error at stoppage time in respect to the baseline was measured as basis for maneuverability. In the second test the response time was compared with a completely randomized design in two systems. The statistical analysis showed a statistically significant difference between the control systems in 1% probability level. The maneuverability of harvester equipped with electronic control system increased significantly and it was not affected by the changes in engine rpm (forward speed). In the second test the statistical analysis showed a statistically significant difference between the control systems in 5% probability level. Electronic forward speed control system resulted in reaction speed, and device maneuverability, ease of maintenance and use, a reduction in mechanical parts usage and finally the proper functioning of the system.

Although the environmental impacts of renewable energies have been broadly investigated, their importance in ensuring energy security has received less attention. This study has investigated the potential of solar electricity generation Ahwaz county, from the energy security point of view. The land erea of Ahwaz county were prioritized based on the geographical, environmental and human factors using fuzzy multi-criteria decision-making and GIS. The results show that the solar energy in Ahwaz county has a great impact on enhancing energy security and has more flexibility regarding natural and human threats. Using only 3.3 percent of lands in the area, it is possible to generate as much electricity as needed in Khuzestan province. Thereby, it is possible to decentralize power generation, which in turn leads to increase the security of energy supply. This amount of solar electricity generation can contribute to reduce the emissions by about 109000 tons per year

High water consumption and the cost of labor in rice transplanting method is the reason for growing tendency of farmers to Dry-bed seeding of rice in Iran. High consumption of seed and inadequate specialized machines are the problems in rice dry-bed seeding. At present rice dry-bed seeding is done with traditional drill seeder with more than of 90 kg/ha seed consumption. While planting one seed in hole with a 20×20cm planting pattern in dry-bed seeding can reduce seed consumption to 5 kg/ha. This research was conducted for fabrication and laboratory evaluation a special seed plate for rice dry-bed direct seeding with pneumatic planter. Design parameters of Seed plate were included six plate shapes and three seed hole diameters. Seed plate shapes included traditional plate without groove and five groove shapes on plate, including three trapezoidal grooves with wall angle of 30, 45 and 60 degrees and two semicircle grooves with the aperture opening 2 and 3mm and three seed hole diameters 1.2, 1.3 and 1.5mm at the three levels of vacuum pressure 40, 50 and 60 milibar compared in a completely randomized design in a factorial experiment with three replications. Indices were, seed number per hole, miss index, over index and precision of feeding index. The results showed that creating the groove on the seed plate resulted higher seed cell covering and reduced miss and over index. New grooved plates had higher precision of feeding and lower miss index than conventional seed plate. By increasing the vacuum pressure and the diameter of the seed hole, miss index decreased and over index and seed number per hole increased. By increasing the angle of the walls of the trapezoid grooves and aperture of the semicircle grooves miss index reduced and over index and seed number per hole increased. In general, the results of laboratory evaluation Showed that for direct seeding of rice in dry-bed condition with pneumatic planter, using the seed plate with trapezoidal groove wall angle of 45 degrees and a diameter of hole 1.2 mm and vacuum pressure 50 mbar were better than others.

This study was carried out in Khouzestan province of Iran. Data were collected from 113 ratoon farms in Debel Khazai Agro-Industry with face to face questionnaire method. The objective of this study was to predict sugarcane production yield and GHG (greenhouse gas) emissions on the basis of energy inputs. Accordingly¡ several ANN (artificial neural network) models were developed and the prediction accuracy of them was evaluated using the quality parameters. The results illustrated that average total input and output energy of sugarcane production were 145117.7978 and 87096.42 MJ.ha-1¡ respectively. Electricity¡ chemical fertilizers and water for irrigation were the most influential factors in energy consumption. The ANN model with 6-7-19-1 and 5-5-1 structure were the best for predicting the sugarcane yield and GHG emissions¡ respectively. The coefficients of determination (R2) of the best topology were 0.96 and 0.99 for sugarcane yield and GHG emissions¡ respectively. The values of RMSE for sugarcane production and GHG emission were found to be 17763522 MJ.ha-1 and 528¡ respectively.

Overall energy efficiency (OEE) is an important indicator of energy consumption in tillage operations. Tillage energy was studied objectivity to accurately measure the OEE of MF399-4WD tractor. The tractor was equipped with different types of sensors to measure and calibrate the required data including: fuel consumption، actual forward speed، wheel speed and slippage، engine speed، draft and drawbar power. The data were recorded with frequency of 1000 Hz and transmitted by employing a suitable wireless technology in the range of up to1. 5 km to the user''s personal computer and is stored in Excel format. The hardware and the software program، which was written in C# language، simultaneously monitor the changes in functional parameters and the monitoring can be done even from far away and via the Internet. The split factorial experiment with three factors including ballast، selected gear ratio and two wheel drive configurations (two and four wheel drive) was employed to perform analysis of variance (ANOVA)، POST ANOVA AND PATH ANALYSIS. The results show that the performance of remote monitoring devices installation was very accurate and high-quality. Furthermore، statistical analysis showed that three parameters including slippage، fuel consumption and tractor Power Equivalent (PEQ) were the most effective parameters on overall energy efficiency of tractors – tillage. The variance analysis showed that the effect of gear ratio and drive configuration on the OEE were also significant at the one percent level. However، ballasting had no significant effect on the OEE.

In mathematical modeling and design of hydraulic systems, it is very important to determine the flow rate through control valves on the basis of discharge coefficient and also the orifice cross section created in the valves. Although the discharge coefficient depends on the oil flow type through the orifice, it is usually assumed as constant in hydraulic valves. Thus, in this paper, the discharge coefficient of orifice created by spool and three conventional poppet types in hydraulic valves were examined experimentally. Then, based on the experimental data, the curve fitting of discharge coefficient versus square root of Reynolds number was extracted for four types of orifice created by the moving members including spool, cone, spherical and cylindrical. Curve assessment showed that the discharge coefficient in turbulent flow for all four types of moving members was constant, but in the laminar flow conditions, the discharge coefficient linearly varied by square root of Reynolds number for them. The discharge coefficient in turbulent flow conditions for the orifice created by spool was lower than the other moving members. While, the slope of the linear part of the discharge coefficient curve for this orifice was more than others.

Delay in irrigated wheat primary tillage operations causes yield reduction and hidden timeliness cost in Fars province. Mechanization of primary tillage operations for irrigated wheat in Fars province was simulated using System Dynamics approach. A part of the model structure was related to the agricultural operations timeliness costs. For the mentioned simulation، causal relations between system components were known and the model was run based on time step of 0. 125 of one year. The simulation results showed that the operations timeliness cost remained constant (approximately one million rials per hectare) from 2001 to 2004 in the province. The timeliness cost increased from 2004 to 2007 due to the non-uniform distribution of atmospheric precipitation and reached to 1211724 rials per hectare in 2007. The upward trend of this cost continued for the period of 2007 to 2010 because of using depreciated moldboard plows. The model predicted the amount of 2090511 rials per hectare for the timeliness cost in 2018. Furthermore، it was found that reduction in the timeliness cost could be reached either by increasing the plowing speed by %30 in the permissible domain or increading the daily working hours by 4 hours.

Crop yield is influenced by seeding quality. In this study, some effective parameters on seeding quality have been surveyed. For this purpose, by use of split-split plot experiment, based on a randomized complete block design with three replications, effect of tillage method, planter type and travel speed on seeding quality indices like skip, single seeding, multiple seeding and seeding precision. Main plots were related to different tillage methods including; 1-mouldboard plow + one pass disk plow (T1), 2-mouldboard plow + two pass disk plow (T2) and 3-mouldboard plow + two pass disk plow + land leveler (T3). Sub plots were related to planter types including; 1- mechanical planter (P1) and 2-pneumatic planter (P2). Sub–sub plots were related planter travel speed including; 1- 4 km/h (S1), 2- 5.5 km/h (S2) and 3- 7 km/h (S3). Variance analysis showed that, tillage method had significant effect on all of the parameters except single seeding index and seeding precision. However, planter type and travel speed have significant effect on none of the parameters. Interaction between tillage method and planter type, have significant effect on all parameters except single seeding. With regard to seeding precision, the best treatment was T1P1 followed by T2P2. Therefore, using T2P1S3 treatment, speed and precision of seeding could be increased.

In the present research, the performance characteristics of a four-cylinder spark ignition engine were investigated using bioethanol – gasoline blends. The experiments were performed in factorial tests with a randomized complete block design with three replications. Factors of experiments were six bioethanol- gasoline blends (E0, E10, E20, E30, E40 and E50) and six engine speeds (2000, 2500. 3000, 3500, 4000 and 4500 rpm). Engine performance characteristics for fuel blends were compared with gasoline. The results of the engine test showed that bioethanol addition to gasoline significantly increased the torque, brake power, and brake thermal efficiency while the brake specific fuel consumption decreased in E10 and increased in E50. Results showed that in all engine speeds, 10 vol.% ethanol in fuel blend gave the best results for torque, brake power and brake specific fuel consumption.