A. Hayati; A. Marzban; M. A. Asoodar
Abstract
Despite the development of dairy farm mechanization, milking operations are still associated with heavy workloads which result in human physiological strains. This study investigated the role of gravity force in the linkage between load carriage and workers’ physiological strains in milking work ...
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Despite the development of dairy farm mechanization, milking operations are still associated with heavy workloads which result in human physiological strains. This study investigated the role of gravity force in the linkage between load carriage and workers’ physiological strains in milking work tasks of two major cow milking systems (milking in stanchion barns and tandem parlors). These two milking methods similarly included washing the teats, attaching the cluster, and detaching the cluster. Human energy expenditure (EE) was calculated and load carriage direction in comparison with gravity (LCG) was tracked among twenty-four male workers. The highest heart rate (107 beats min-1) and EE (35.5 kJ min-1) were reported for attaching the cluster in the tandem parlor milking method. Tandem parlor milking caused higher human physiological strains and higher proportions of converse LCG compared with stanchion barn milking. By developing dairy farm mechanization from stanchion barn to tandem parlor, cow milking workers are induced to apply higher forces including converse LCG causing higher human physiological strains. Mechanization of dairy farms should be developed not only for improving the rate of work and performance but also for making conditions toward a reduction in the use of human physical forces.
H. Nematpour Malek Abad; M. J. Sheikhdavoodi; I. Hazbavi; A. Marzban
Abstract
Contamination due to hydraulic fluids exerts deleterious effects after a long time, however this factor is often ignored or its consecutive breakdowns and system failures are considered due to other factors. Therefore, in order to prevent the likelihood of occurring such problems, the following two strategies ...
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Contamination due to hydraulic fluids exerts deleterious effects after a long time, however this factor is often ignored or its consecutive breakdowns and system failures are considered due to other factors. Therefore, in order to prevent the likelihood of occurring such problems, the following two strategies are presented: using oil change method to replace all of the hydraulic fluids from the discharge system with the new oil and using offline hydraulic oil filtration system for the removal of contaminated oil particles. In this regard, the present study aimed to investigate the economic status of cane sugar harvesting machines with an emphasis on hydraulic oil filtration process in seven units of sugarcane developmental company and affiliated industries in Khuzestan province, Iran. To perform this study, all statistics and data of the sugarcane and affiliated industries in seven companies during the crop year 2011-2016 were collected and classified. The results indicated that the application of the hydraulic filtration method led to the oil consumption saving (per liter) and in price (Iranian Rial) during the three crop-years of 2014-2016, as following: Imam Khomeini: 25500 L and 2882154363 Rials, Amir Kabir: 49000 L and 5847389466 Rials, Hakim Farabi: 82000 L and 9534396744 Rials, Dabal Khazaee: 73400 L and 6808230362 Rials, Dehkhoda: 31680 L and 3421979639 Rials, Salman Farsi: 73500 L and 7606675370 Rials and Mirza Koochak Khan: 75934 L and 8083068395 Rials.
F. Afsharnia; A. Marzban
Abstract
Introduction Optimal operation and maintenance of engineering systems heavily relies on the accurate prediction of their failures. Repairable engineering systems are well known in industries. A repairable engineering system indicates that the performance of this system after each failure can be restored ...
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Introduction Optimal operation and maintenance of engineering systems heavily relies on the accurate prediction of their failures. Repairable engineering systems are well known in industries. A repairable engineering system indicates that the performance of this system after each failure can be restored through suitable maintenance. It is normally a complex system composed of a number of components. Failure prediction of a repairable system and its subsystems is an important topic in the reliability engineering. One of the most important repairable systems in agro-industrial companies is the sugarcane harvester. This machine has a key role in harvesting operations of sugarcane plant. The failures of this machine causes delay in operations and reduce products yield and quality. Currently, preventive maintenance is conducted on these harvesters to improve the overall reliability of these systems. Therefore, in this study, the long-term effect of preventive maintenance strategy on the efficiency and failure rate of the sugarcane harvester was investigated. Materials and Methods This research was carried out on 30 sugarcane harvesters used by sugarcane and by Products Development Company of Khuzestan during 6 years period. The goal of this study was to introduce a methodology aimed to acquire the information to predict the effect of preventive maintenance strategy on the failure rate and efficiency of sugarcane harvester by time series. Time series forecasting is the use of a model to predict future values based on previously observed values. The expected shape is a forecast from a combination of an ARIMA models (AR, MA, ARMA and ARIMA). The first step in analyzing the time series is plotting the data and obtaining the sample records. The next step is consideration of a trend and periodic components and remove them from the time series and fitting the static model on the time series. The next stage is implementation of the data normalization using skewness coefficient method and their normalization through logarithm differentiation of data. The arithmetic mean of data was applied to obtain zero average of the time series. Sample ACF (Auto Correlation Function) and PACF (Partial Auto Correlation Function) was drawn and then the model rank "a" was recognized and selected by comparison of ACF and PACF for AR, MA, ARMA, and ARIMA models. Results and Discussion According to the results of failure rate related to the sugarcane harvester, it can be found that the mean failure rate of this machine for the 6-years period was equal to 0.147 per hour. The minimum and maximum value of the failure rate were 0 and 0.517 per hour, respectively. The mean annual use hours of these harvesters was 189.8 h. Although the accumulated used hours increased, the mean time between failures (MTBF) was increased. According to Jacobs et al. (1983), the machines may breakdown due to a design defect, physical damage, or normal wear and tear, but many times machines fail because of a neglect and the lack of properly scheduled maintenance. In this study, implemented preventive maintenance resulted in decreasing of failure rate and increasing of machine efficiency as well. In 2016, the failure rate of sugarcane harvester was decreased by 73.23% and the machine efficiency was increased by 14.9% compared to 2011, because timely preventative maintenance and inspection will not only help to reduce major problems and downtime, but it will also help to identify problems when they can be corrected with relatively minor repairs. Among the 12 studied subsystems, topper, electric and motor subsystems were more affected by preventive maintenance by 94.75%, 80.46% and 58.74% decreasing in the failure rate, respectively. With regard to the evaluation criteria such as AIC, MAPE and RMSE, the ARIMA (1, 3, 2) model was determined as a suitable model for predicting the failure rate of sugarcane harvester. Furthermore, there is no significant difference between statistical descriptive measures of forecasting and actual tractor failure rate that it represents high accuracy of forecasting via ARIMA model. Conclusion This study was adapted to the preventive maintenance as a useful strategy that could increase availability and operational efficiency of the sugarcane harvester. Furthermore, it focused on time series modeling method to analyze and forecast the reliability characteristics such as the expected number of failures per interval (failure rate). It is found that time series model is a viable alternative that gives satisfactory results for interval failure predictions in terms of its predictive performance for the sugarcane harvester reliability.
H. Nematpour Malek Abad; M. J. Sheikhdavoodi; I. Hazbavi; A. Marzban
Abstract
The purpose of this study was to model and optimize the offline refinement operations of sugarcane harvester hydraulic oil using RSM. For this purpose, the effects of independent variables of operating hours (250, 500 and 750 hours), Twin Dip Filter Mesh (7, 9 and 11 microns) and hydraulic oil refining ...
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The purpose of this study was to model and optimize the offline refinement operations of sugarcane harvester hydraulic oil using RSM. For this purpose, the effects of independent variables of operating hours (250, 500 and 750 hours), Twin Dip Filter Mesh (7, 9 and 11 microns) and hydraulic oil refining times (0, 1 and 2) on variables of water contamination, uncleanness level (NAS), silicon (Si), viscosity (Vis) and oil acid number (TAN) were evaluated. The results indicated that all models were suitable for water contamination, uncleanness level (NAS), silicon (Si), viscosity (Vis) and oil acid number (TAN) for describing experimental data. In addition, the desirability function showed that the optimum conditions for the offline refinement operations of the hydraulic oil of the sugar cane harvester included 728.61 operating hours, the 7-micron filter mesh, and the two refining times of the oil. Under this condition, the amount of water contamination, the uncleanness level (particles 5 to 15 micrometers), Vis, Si, and TAN were equal to 187.63 ppm, 234000, 5.91 ppm, 66.34 centistokes and 0.65 (mg KOH g-1), respectively.
F. Afsharnia; A. Marzban
Abstract
Introduction Given the risk management and improving the process, reliability is important in operations and production management, especially agricultural process. Failure modes and effects analysis (FMEA) is regarded as one of the most powerful methods in this area. High applicability and proper analyzability ...
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Introduction Given the risk management and improving the process, reliability is important in operations and production management, especially agricultural process. Failure modes and effects analysis (FMEA) is regarded as one of the most powerful methods in this area. High applicability and proper analyzability of FMEA have caused to be among the most important techniques of systems for risk analysis and safety improvement. Risk management in all sectors is important, especially in agricultural sector. Sugarcane is one of the industrial crops used as raw material for several major and minor industries. In Iran, this crop is cultivated by sugarcane agro-industry companies. The sugarcane trailers were used to transport harvested sugarcane from farm to mill in these companies. There are many problems to milling it on time. One of the most important risks involved in sugarcane transportation is the delays encountered in this process which can affect the quality and quantity of the product. Delay in milling of the harvested sugarcane is caused by various reasons in agro-industry units including factory downtime, breakdowns of tractors at factory gate, tractor accident in factory yard and staff shift changes creating long queues. So, considering and using risk management techniques and eliminating risk factors can be an effective step to increase the efficiency of this process. Materials and Methods This research was carried out on Sugarcane and By-Products Development Company of Khuzestan. At first, the sugarcane transport operations and used equipment were investigated through an interview with experts in the safety and technical sectors and engineers of the Sugarcane and By-Products Development Company of Khuzestan and the study of related books in 2017. After that, the defects and errors of each equipment that caused technical problems and problems in other equipment, as well as the occurrence of injuries and human casualties were identified. Finally, the risks were written for valuation in the FMEA method paper. In this research, risk pricing was based on the Brainstorming method. Risk evaluation is based on the ranking of the effect severity, the risk occurrence probability and the degree of risk detection available in the FMEA method. In this research, analytical network process (ANP), a modern and powerful method in the decision-making field, has been used in combination with FMEA (FMEA-ANP) for defeating the shortcomings. FMEA-ANP considers mutual relationships of hazardous factors, and by offering a certain structure, develops a systematic and flexible view in risk management scope. The suggested method deploys a simple concept of risk priority number and assigns different importance in the form of power for each factor. The resulted RPN will cope better with the system, in which it is applied. This method provides a more accurate analysis of risk and, consequently, more efficient and effective actions, causing attainment and maintenance of more desirable reliability. Results and Discussion The results of FMEA-ANP model indicated that the mill equipment in the sugar factory is the most important delayed factor (failure) in the sugarcane transformation. For this reason, the basis failure causes in the sugar factory has been carefully investigated and it has been concluded by experts' opinions that factory mill and the conveyers failures are important causes of the delay in this process, respectively. Based on statistical analysis, 73.15% of the factory downtimes were related to mill and ranked as first compared with the other risk factors. Among the conveyors, the most damage was related to the inlet conveyor to the first mill and 49% of conveyors failures occurred in this conveyor. Conclusion This research validated the application of FMEA-ANP for the rational organization of the harvest-transport complex. According to this investigation, the probable downtimes and delays can be prevented by implementing the optimal preventive repair and maintenance planning in the sugar factory, and in particular on the factory mill equipment. In addition, efforts to adapt the speed of harvesting and the speed of delivery by the factory can be effective in reducing the delivery delay time by the factory.
A. Keshvari; A. Marzban
Abstract
Introduction Understanding the status of tractor power in any region is a key factor in setting a mechanization planning to improve the capacity of mechanized operations. For this reason, it is necessary that the available tractor power in each region meet the needs of agricultural operations in the ...
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Introduction Understanding the status of tractor power in any region is a key factor in setting a mechanization planning to improve the capacity of mechanized operations. For this reason, it is necessary that the available tractor power in each region meet the needs of agricultural operations in the most demanding time of cropping season in terms of operations related to machinery. Materials and Methods The objective of this study is needs assessment and prioritizing the power arrival in the agriculture of Khuzestan province. Required data, such as the number of tractors, areas under crop cultivation, size and number of farmlands, and crop yield were collected from the beginning of the first economic, social and cultural development plan until the end of the fifth development plan. Given to peak of operations, working hours per day and the probability of working days, input power required for each county was calculated. To determine the priorities for arrival power to counties, four criteria, including mechanization level shortage, percentage of obsolete tractors, the harmonic mean of production and area (ha) per tractor ratio (ha/tractor) were applied using TOPSIS-AHP based approach. Technique for order preference by similarity to ideal solution (TOPSIS) is one of the strongest methods in multi-criteria decision making. This method is based on the calculation of geometric distance of alternatives from positive ideal solution and negative ideal solution. Analytical hierarchy process (AHP) was used for weighting to criteria. AHP is one of the most famous multi-criteria decision making methods which has been used to estimate a total score for each criterion, compare indices using pairwise comparison and assess their score for one criterion. AHP is based on the decision-maker experience and knowledge. But since decision-makers rely on their mental ability and experience for doing comparisons, for reasons such as inadequate knowledge and information, complexity of the problem, lack of confidence in decision-making environment and lack of a proper scale, they are not able to express their preferences in the form of pure numbers. So conventional AHP has not enough potential for working based on human thinking style. For solving this problem, the theory of fuzzy sets can be used. Results and Discussion Based on the results, 6682 tractors with theoretical power equivalent as 75 hp should be added to provincial fleet to ensure timely agricultural operations in Khuzestan province. The required 75-hp tractor units are 1163, 750 and 742 for Dasht-e Azadegan, Andimeshk and Ahvaz, respectively and Abadan, Khoramshahr, Shadegan, Shushtar, Shush, Andika, Bavi, Behbahan and Hendijan did not need to import any new power due to higher theoretical power available compared to required power. The needs difference of counties came from the difference between counties area under cultivation in the peak work area. Almost there was one tractor per 50-ha area under cultivation in the province. Mechanization level was calculated as 1.2 hp ha-1. Based on the tractor classification by Mechanization Development Center, tractors over 13 years age are known as obsolete, so mechanization level could be reached down to 0.7 hp ha-1 by eliminating these tractors that included 40% of total tractors in the province. Coefficient of variation related to the mechanization level of counties was calculated as 47% that indicates imbalance between provincial regions. The average of variation coefficient of farm lands was obtained as 301.96 % for the province. Also correlation between mechanization level and coefficient of variation of farmlands was -0.436 in 5% level. In order to determine the priorities for importing power to each region of Khuzestan province, the ratio of area under cultivation (ha) to tractor unit assigned highest weight (0.3, 0.41, 0.54). Gotvand, Andimeshk, Izeh and Bagh-e Malek, had highest priority for importing power, respectively. Conclusion Results indicate an inappropriate distribution of tractors without considering the actual local need for them. Appropriate distribution of power is more important than quantitative distribution of tractors in Khuzestan province, because power in some regions is more than required power that cause wasting capital. In opposite, the shortage of power resources in the peak of workload in other regions, cause timeliness costs for farmer. Based on this, a necessity for regional planning is felt in the provincial strategic plans to make appropriate and coherent environments.
N. Monjezi; M. J. Sheikhdavoodi; H. Zaki Dizaji; A. Marzban; M. Shomeili
Abstract
Introduction Planning and scheduling of farming mechanized operations is very important. If the operation is not performed on time, yield will be reduced. Also for sugarcane, any delay in crop planting and harvesting operations reduces the yield. The most useful priority setting method for agricultural ...
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Introduction Planning and scheduling of farming mechanized operations is very important. If the operation is not performed on time, yield will be reduced. Also for sugarcane, any delay in crop planting and harvesting operations reduces the yield. The most useful priority setting method for agricultural projects is the analytic hierarchy process (AHP). So, this article presents an introductry application manner of the Analytical Hierarchy Process (AHP) as a mostly common method of setting agricultural projects priorities. Analytic Hierarchy process (AHP) is a decision making algorithm developed by Dr. Saatyin 1980. It has many applications as documented in Decision Support System literature. Currently, this technique is widely used in complicated management decision makings which AHP was preferred from other established methodologies as it does not demand prior knowledge of the utility function; it is based on a hierarchy of criteria and attributes reflecting the understanding of the problem, and finally, because it allows relative and absolute comparisons, thus making this method a very robust tool. The purpose of this research is to identify and prioritize the effective parameters on lack of timeliness of operations of sugarcane production using AHP in Khuzestan province of Iran. Materials and Methods The effective parameters effecting on lack of timeliness of operations have been defined based on expert’s opinions. A questionnaire and personal interviews have formed the basis of this research. The study was applied to a panel of qualified informants made up of fourteen experts. Those interviewed were distributed in Sugarcane Development and By-products Company in 2013-2014. Then, by using the Analytical hierarchy process, a questionnaire was designed for defining the weight and importance of parameters affecting on lack of timeliness of operations. For this method of evaluation, three main criteria considered were yield criteria, cost criteria and income criteria. Criterions and prioritizing of them was done by questionnaire and interview with sophisticated experts. This technique determined and ranked the importance of criteria affecting on lack of timeliness of operations based on attributing relative weights to factors with respect to comments provided in the questionnaires. By using of software (Expert choice) Analytical Hierarchy Process was done and the inconsistency rate on expert judgments was investigated. Expert Choice software (Expert Choice 1999) was applied to examine the structure of the proposed model and achieve synthesis/ graphical results considering inconsistency ratios. Results and Discussion The Expert Choice software performed well in conjunction with the panel of experts for choosing the criteria and assigning weights under the AHP methodology. According to results, effective parameters on lack of timeliness of operations of sugarcane production consist of delays caused by management, delays caused by human, delays caused by machine and delays caused by procedure (the production process).Weight of criteria effective factors (yield, cost and income) on lack of timeliness of operations obtained from paired comparison in the experts’ view which has been calculated with Expert choice software. The result of this survey by AHP techniques showed that cost criteria had the most and income criteria had the least importance for expert in sugarcane production. In this stage of research, alternatives paired comparison relative to criteria was separately formed and information of questionnaire which relates to paired comparison of criteria was obtained. Between effective parameters on lack of timeliness of operations, machine factors to 0.366 weighted average was the most effective factor and production process to 0.298 weighted average, management factors to 0.177 weighted average and human factors to 0.160 weighted average was later respectively (Inconsistence Rate =0.03). The results are examined by monitoring sensitivity analysis while changing the criteria priorities. Since different judgments are made on comparison of criteria, we use sensitivity analysis in order to provide stability and consistence of analysis. With increase or decrease of the criteria, we will conclude that ratio of other indices will not change. Conclusion The analytic hierarchy process, as developed by Saaty, has been successfully applied in recent research to cases of agricultural project. This paper looks at AHP as a tool used in Sugarcane Agro-Industries to help in decision making. Results showed that criteria studied in this research can help prioritizing the effective parameters on lack of timeliness of operations of sugarcane production. Cost criteria are the main criteria effective on lack of timeliness operations of sugarcane production. The most important factor is machine factor.
Image Processing
F. Behzadi Pour; M. Ghasemi-Nejad Raeini; M. A. Asoodar; A. Marzban; S. Abdanan Mehdizadeh
Abstract
Introduction Today, attention to safety and environmental issues in all sectors in agriculture, industry and services is very important. Chemical poisons play an important role in rapid progress of agricultural products. Every year about 25 to 35 percent of the world's crops are affected by insects, ...
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Introduction Today, attention to safety and environmental issues in all sectors in agriculture, industry and services is very important. Chemical poisons play an important role in rapid progress of agricultural products. Every year about 25 to 35 percent of the world's crops are affected by insects, weeds and plant pathogens disappear and this figure would be raised to 80% if no control was applied. Drift problem and its devastating effects are the most important issue which related to users and sprayers manufacturers. Spray drift reduction and improvements in the efficiency of pesticide application processes are global goals. Where ever spraying is applied, drift will be produced and it must be controlled by controlled of the droplet size. The application of these sprayers is the high in the farms (the number of 2303 in Iran). So, this research was carried out to improve the quality of work in these sprayers by studying the droplets diameter and the spray quality index. Materials and Methods The research was conducted at the University of Khouzestan Ramin Agriculture and Natural Resources. Tests were done with 20 m of water sensitive papers at a distance of 2 meters from each other. To evaluate the technical items affecting on drift, an experiment was conducted using a turbo liner sprayer (TURBINA S.A. 800) and the John Deer (JD) 3140 tractor. A completely randomized factorial design was applied. By using 3 replications and the factors were spraying pressure applying three levels (10, 25 and 35 bar), the fan speed with two levels (1998 and 2430 rpm) and forward speed with two levels (9 and 13.5 km hr-1). The sprayer started the application, spraying a solution of water and tracer (yellow Tartrazine E 102), 15m before the water sensitive papers and then moved over the water sensitive papers. The spraying was continued 15 m after the end of the sampling area. After spraying, sensitive papers were photographed and then volume diameter of 50% (DV50) and median numerical diameter (NMD) and spraying quality indicator were calculated. A Spectrophotometry device at the wavelength of 427 nm, Image J and sas 9.2 software were used for measurement. This research was carried out in accordance with the calendar crop canola spraying in field conditions and the weather was calm that the wind speed was 0- 2.5 km hr-1, relative humidity was 29.7% - 32.5% and air temperature was 18.8˚C – 20.7˚C. Results and Discussion According to the results sprayer pressure, fan speed and forward speed were shown significantly different (P≤0.01) on the volume diameter of 50% (DV50) and median numerical diameter (NMD). The effect of spraying pressure on distributing quality indicator was shown significant (P ≤ 0.01), but the fan and forward speed did not shown any significant effect. Mean comparison of the interaction of pressure and forward speed on the spray quality index and the number median diameter were shown significant (P ≤ 0.01), but they did not shown any significant effect on the volume diameter of 50% (DV50). With increasing spraying pressure and fan speed, the droplet size, volume diameter of 50% (DV50) at 72% and numerical median diameter (NMD) at 69% and distributing quality indicator at 46% were decreased that were corresponded with the result of Czaczyk et al. (2012), Peyman et al. (2011), Nuyttens et al. (2009) and Landers and Farooq (2004). With increasing spraying pressure and forward speed, the droplet size, numerical median diameter (NMD) at 63% and distributing quality indicator at 35% were decreased that these resulted were corresponded with the results of Naseri et al. (2007) and Dorr et al. (2013). Conclusion With increasing spraying pressure, fan and forward speed, the droplet size, volume diameter of 50% (DV50) and numerical median diameter (NMD) were decreased. Therefore, spraying quality indicator was decreased. The maximum pressure (35 bars), maximum fan speed (2430 rpm) and maximum forward speed (13.5 km hr-1) were able to produce the minimum spraying quality indicator (10.3). At the minimum pressure (10 bars), maximum fan speed (2430 rpm) and minimum forward speed (9 km hr-1), the maximum spraying quality indicator (2.91) was resulted.
M. Hamid; H. Zaki Dizaji; A. Marzban
Abstract
Introduction: Nowadays, the tractor mounted boom sprayer is used in many agricultural fields. These sprayers have many advantages compared to other sprayers, but in Iran, their field efficiency is much lower than that of the developed countries, because the tank volume and consumption of pesticides per ...
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Introduction: Nowadays, the tractor mounted boom sprayer is used in many agricultural fields. These sprayers have many advantages compared to other sprayers, but in Iran, their field efficiency is much lower than that of the developed countries, because the tank volume and consumption of pesticides per hectare is often so highthat spraying per hectare takesa long time for handling the solutions and transporting the sprayers. Also spray droplet size is ordinarily high and its distribution is unknot uniform. So, often spraying and dropping top parts of plants on the earth is inevitable. According to studies carried out in the country during the years 2005-2008 in the agricultural research centers in several provinces such as Khuzestan, four types of sprayers including tractor mounted sprayer, atomizer, microner, and electrostatic atomizer were studied and some of the results obtained include the following. From the point of view of percentage of crash crop, tractor mounted sprayer has the highest percentage, but microner sprayer had the lowest. From the point of view of the solution of consumption amount and spraying cost per hectare, the operation of the tractor mounted sprayer and electrostatic sprayer had the highest and the lowest ranks, respectively. Atomizer sprayer had the highest effect on the percentage amount of weed control, but it requires a high amount of water consumption, high drift and low operation (Safari and Lovaimi, 2010).
Materials and Methods: The experiment was carried out during 2012-2013 in the field of agricultural research located in the Mollasani city located 20 km near Ahvaz. In this study, tractor mounted spinning disk sprayer (mounted microner sprayer) was evaluated in comparison with conventional boom sprayer on weeds control. The treatments included medium (3500 rpm) and low (2000 rpm) speed rotation disk sprayer and two types of nozzle in conventional boom sprayer. One of them was an Italian tee jet nozzle and the other one was flowage nozzle and they were compared with control treatment. Experiment design was Randomized Completed blocks Design (RCBD) with seven replications. Parameters such as spraying quality, diameter, volume mean diameter and numerical mean of droplets, spray quality factor, the percentage of crash crop, weeds dry weight and number, percentage of weed control and the drift were measured. The results were compared with a control treatment. For comparative tests between the sprayers, the measured parameters were compared with each other using SAS software.
Results and Discussion: Volume mean diameter and numerical mean diameter in tractor mounted microner sprayer with medium and low speed rotation disk treatment and also tractor mounted boom sprayer with Italian fan nozzle treatment were metered 162.5, 461 and 635.5 micron, and 138.5, 355 and 452.5 micron, respectively. Volume mean diameter related to numerical mean diameter was obtained to be 1.17 and 1.3 for tractor mounted microner sprayer with medium and low levels of speed rotation disk, and 1.4 for tractor mounted boom sprayer with Italian fan nozzle, respectively. Whenever the spray quality coefficient is closer to one, the spray quality is better. So microner sprayer treatment with 1.17 coefficient has the best spray quality. The results about weeds control numbers showed all treatments had significant difference with control treat in 1% levels (Table 3). Evaluating all treatment results showed the flowage nozzle with 22.57 weeds number and 27.26 g. weeds dry weight had significant difference with other treatments in 1% levels that was the best operation (Table 4). In comparison of sprayers’ technical evaluation, all treatments had significant difference in 1% levels, so the flowage nozzle with 191.66 l.ha solution consumption and microner treatment with medium speed rotation disk with 44.38 l.ha solution consumption were the most and the least treatments. And they have significant difference in 1% levels (Table 5). The most percent of crop loss belonged to sprayer boom tractor with flowage nozzle (27.03%) and the least belonged to microner boom sprayer tractor (6%). The most percent of drift belonged to microner boom sprayer tractor with medium speed of rotation disk (76.19%) and the least belonged to sprayer boom tractor with flowage nozzle (23.81%). The best spraying quality (1.17) was for microner with medium rotation disk treat (Table 6).
Conclusions: Performance of a sprayers mostly depends upon the working of its nozzle. In this research, two different sprayers with three typical nozzles were used to control wheat crop weeds. In general, the tractor sprayer of microner (40 million Rials) is more expensive than the typical boom sprayer, and because most farmers owntractor mounted boom sprayers the most convenient and least expensive method is to use Italian fan nozzle (standard) due to lower cost and higher performance. However, there are many effectiveness parameters to select a suitable sprayer for the field. But on the bases of the sprayer's technological specifications, weed control parameters, economical parameters and etc., technical methods such as Analytical Hierarchy Process (AHP) or other ones are proposed to choose the better sprayer for pesticide applications.
P. Najafi; M. A. Asoodar; A. Marzban; M. A. Hormozi
Abstract
Introduction: The performance of agricultural machines depends on the reliability of the equipment used, the maintenance efficiency, the operation process, the technical expertise of workers, etc. As the size and complexity of agricultural equipment continue to increase, the implications of equipment ...
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Introduction: The performance of agricultural machines depends on the reliability of the equipment used, the maintenance efficiency, the operation process, the technical expertise of workers, etc. As the size and complexity of agricultural equipment continue to increase, the implications of equipment failure become even more critical. Machine failure probability is (1-R) and R is machine reliability (Vafaei et al., 2010). Moreover, system reliability is the probability that an item will perform a required function without failure under stated conditions for a stated period of time (Billinton and Allan, 1992). Therefore, we must be able to create an appropriate compromise between maintenance methods and acceptable reliability levels. Precision failure data gathering in a farm is a worthwhile work, because these can represent a good estimate of machine reliability combining the effects of machine loading, surrounding effects and incorrect repair and maintenance. Each machine based on its work conditions, parts combinationand manufacturing process follows a failures distribution function depending on the environment where the machine work and the machine’s specifications (Meeker and Escobar, 1998). General failures distributions for contiguous data are normal, log-normal, exponential and Weibull (Shirmohamadi, 2002). Each machine can represent proportionate behavior with these functions in short or long time.
Materials and methods: The study area was the Hakim Farabi agro-industry Company located 35 kilometers south of Ahvaz in Iran. Arable lands of this company are located in 31 to 31°10 N latitude and 45 to 48°36 E longitudes. The region has dry and warm climate. A total of 24 Austoft 7000 sugarcane chopper harvester are being used in the company. Cane harvesters were divided into 3 group consisting of old, middle aged and new. From each group, one machine was chosen. Data from maintenance reports of harvesters which have been recorded within 400 hours were used. Usually, two methods are usedfor machine reliability modeling. The first is Pareto analysis and the second is statistical modeling of failure distributions (Barabadi and Kumar, 2007). For failures distribution modeling data need to be found, that are independent and identically (iid) distributed or not. For this, trend test and serial correlation tests are used. If the data has a trend, those are not iid and its parameters are computed from the power law process. For the data that does not havea trend, serial correlation testare performed. If the correlation coefficient is less than 0.05 the data is not iid. Therefore, its parameters reach via branching poison process or other similar methods; if the correlation coefficient is more than 0.05, the data are iid. Therefore, the classical statistical methods will be used for reliability modeling. Trend test results are compared with statistical parameter.
A test for serial correlation was also done by plotting the ith TBF against the (i-1)th TBF, i ¼ 1; 2; . . . ; n: If the plotted points are randomly scattered without any pattern, it can be interpreted that there is no correlation in general among the TBFs data and the data is independent. To continue, one must choose as the best fit distribution for TBF data. Few tests can be used for best fit distribution that include chi squared test and Kolmogorov–Smirnov (K-S) test. Chi squared test is not valid when the data are less than 50. Therefore, when the TBF data are less than 50, K-S test must be used. Hence, the K-S test can be used for each TBF data numbers. When the failure distribution has been determined, the reliability model may be computed by equation (2).Results and discussion: Results of trend analysis for TBF data of sugarcane harvester machines showed that the calculated statistics U for all machines was more than chi squared value that was extracted fromthe chi square table with 2 (n-1) degrees of freedom and 5 percent level of significance. Hence, it is possible that all of the machines’ TBF data will have identically and independent distributions. For validating this hypothesis, correlation testwas performed on TBF data that verified prior results. Then, Kolmogorov- Simonov test was done on TBF data. Results showed that all three machines followed Weibull 3 parameters function, but the shape parameter was different for them. The analysis showed the shape parameter for old, middle aged and new cane harvesters was 1.5, 1.42 and 1.35, respectively.
Conclusions: In order to control and reduce failures and to plan and schedule the harvester operations in optimum time, machine reliability must be known. In this paper, three sugarcane harvesters were studied individually. From the trend analysis and serial correlation, it is seen thatthe assumption of identically and being independently distributed was valid for all machines’ TBF data of sugarcane chopper harvesters.
