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The sesame oil is accounted as high-priced and high-quality oil, but its production is less than that of major oilseeds due to labor-intensive harvest similar to many agricultural activities. These types of activities are often onerous leading the workers to occupational risk factors such as musculoskeletal disorders. Thus, the aim of this study was to evaluate the manual sesame seed harvest (consisting of work tasks of mowing, tying and shaking) regarding postural workloads to identify onerous activities during this operation which would help to mitigate some problems of the sesame seed production chain. Ovako Working posture Analysis System (OWAS) was used for working posture analysis of twenty-six male workers employed for this study. Results showed that stooped and squatting postures were the most common awkward postures similar to other agricultural activities. Posture rotation was recommended as a potential simple ergonomic solution in the present study. Whereas the work task of tying had the highest requirement for corrective measures, most onerous work task could be shaking, due to the low probability of success of posture rotation implementation in it. About this work task, onerous acts may not be mitigated but by introducing a tool. But about some work tasks (i.e. in the work tasks of mowing and tying) ergonomic recommendations including posture rotation could be introduced when the mechanization and technology are still not entered. Overall, further studies would be conducted to discover the effects of some simple ergonomic interventions and manual or mechanized tools in manual sesame seed harvest. [ABSTRACT FROM AUTHOR]

Whereas mechanization and automation are developed in farm works especially in dairy farm working, hand milking method that includes physically demanding tasks is still very current among dairy farmers in Iran. The aim of present study was to assess the physically demanding nature of hand milking method including "washing the teats" and "milking". Ten male workers were selected to evaluate their cardiorespiratory and energy-based demands. Results revealed that working heart rate (HR work) of washing the teats and milking operations were 90.7 and 104.3 beats/min respectively. Energy expenditure rate (EE) of milking was about 1.4 times higher than washing the teats and operation's energy expenditure (OEE) of the milking was about 36.4 times higher than washing the teats. Milking operation occupied a higher proportion of total cycle time (5.37 min) than washing the teats (0.2 min). It could be said because of enhancing cycle time (as first factor) and enhancing heart rate (as second factor) interfered with OEE-enhanced milking operation in hand milking method. The present study shown hand milking method in dairy farm can be categorized as moderate work in the case of heart rate, and light work based on Borg scale. [ABSTRACT FROM AUTHOR]

Work-related Musculoskeletal Disorders (WMSDs) are a leading cause of disability, work time loss and economic loss in both industrialized and developing countries. WMSDs include muscles, bones, joints, nerves and blood vessel disorders. According to the studies done by some researchers, the lack of harmony between technology and the technology users in workplace can degrade the product quality and increase the injuries. In the present study, an ergonomic investigation was conducted and the position and posture of the workers of tea factories were evaluated. REBA and OWAS methods were used for analyzing the postures. The energy expenditure of workers was calculated by heart rate monitoring. In this study, 6 tea factories were considered and totally 48 workers were assessed. Production units of tea factories were classified into three categories, including withering unit, curling and oxidation unit and drying and grading unit. Results showed that 75% of used postures by the workers of tea factories need corrective measurements. Also, based on the OWAS results, 34% of used postures had high and very high risk levels. Worker' back flexion, placing one arm above shoulder and standing on one leg are the most important positions in tea factories, which lead to musculoskeletal disorders. Thus, the corrective measurements should be done to reduce them. Withering unit was the most energy-consuming unit for workers. The average of energy expenditure of tea factories workers was 21.843 kJ min-1. [ABSTRACT FROM AUTHOR]

This paper presents a GERT method based on fuzzy theory for solving fuzzy project scheduling of sugarcane production (preserve operations, harvesting and rationing) in Khuzestan province of Iran. In this method, activity duration time and loops, repetition number, and output activities from nodes of network belong to a fuzzy set. First, an analytical approach was proposed to simplify the structure of network. Then, GERT network computations were done based on evaluating nodes. Process outputs were scheduled network and project fuzzy completion time. These outputs were fuzzy numbers and can be analyzed by α-cut. Results prove that the method of using fuzzy numbers and fuzzy relation in project scheduling is a powerful tool to estimate time for agricultural mechanization projects. [ABSTRACT FROM AUTHOR]

The use of tractors for agricultural works showed an important role to mechanized agricultural sector. A repairable mechanical system (as agricultural tractor) is subject to deterioration or repeated failure. In this study, the regression model was used to predict the failure rate of MF399 tractor. The machine failure pattern was carefully studied and key factors affecting the failure rate were identified in five regions of Khouzestan province. The tractors grouped in four sub groups according to annual use hours and maintenance policies (corrective maintenance and preventive maintenance). Results showed that the majority of recorded failures were observed in the electrical system (20.3%) for each machine sub-group. Maximum and minimum annual repair and maintenance costs were related to other (tire, ring, ball bearing and operator seat) and brake system respectively. According to the results of the research, different annual use hours and maintenance policies affected failure rate. The tractors included in 300-1,000PM subgroup were mostly in the useful life period while the machines were towards the wearing out period of machine life for 300-1,000CM subgroup. The tractors maintained under 1,200-2,000PM subgroup showed an obvious indication of wear-out period entrance, while the tractors were mostly in the wear-out period for the 1,200-2,000CM sub group. The tractors included in 300-1,000 annual use hours were commonly in a randomized breakdown period during their useful life but these tractors tend to enter the wear out period in the 1,200-2,000 annual use hours. So, annual use hours were more effective on failure rate in comparison with maintenance policies. [ABSTRACT FROM AUTHOR]

Tractors play an important role in agricultural mechanization. A repairable mechanical system (as agricultural tractor) is prone to deterioration or repeated failures. In this study, the owners of three hundred tractors, which include Massey Ferguson (MF285 model and MF399 model), John Deere (JD3140 model) and Universal (U650 model), were interviewed, from five regions of Khouzestan Province. A regression model was used to predict the tractors failure rate. The machine failure pattern was carefully studied and key factors affecting the failure rate were identified in these regions. The data obtained from farm records valid by using questionnaire was separated into two groups according to how those tractors were stored. Results showed that the majority of recorded failures were observed in the electrical system for all tractors. According to the results of the research, different storage policies significantly affected the failure rate for MF285, MF399 and JD3140 tractors (63%, 55.5% and 61.6% respectively), whereas inside storage of U650 tractors slightly decreased the failure rate (7.4%). Also, closed storage condition was found to reduce annual repair and maintenance costs by 33.6%, 33.6%, 29.6% and 2.56% in comparison with open air storage condition for the study tractors respectively. The observational estimate showed that all tractors were in the wear out period under outside storage conditions, against inside storage had a considerable effect on the failure rate of MF285, MF399 tractors and they were commonly in a randomized breakdown period within their useful life, JD3140 tractors were in the beginning of wear out period, but U650 tractors were in the wear out period for both storage conditions. Therefore, it can be said that by storing the tractors out of the weather conditions slowly exposed by failure and breakdowns, especially in warm climate and presented of dust haze phenomenon. [ABSTRACT FROM AUTHOR]