AMA, Agricultural Mechanization in Asia, Africa and Latin America (AMA) (issn: 00845841) is a peer reviewed journal first published online after indexing scopus in 1982. AMA is published by Farm Machinery Industrial Research Corp and Shin-Norinsha Co. AMA publishes every subjects of general engineering and agricultural engineering.
AMA, Agricultural Mechanization in Asia, Africa and Latin America (ISSN: 00845841) is a peer-reviewed journal. The journal covers Agricultural and Biological Sciences and all sort of engineering topic. the journal's scopes are in the following fields but not limited to:Azerbaijan Medical Journal Gongcheng Kexue Yu Jishu/Advanced Engineering Science Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery Interventional Pulmonology
Aiming at the problems of irregular ditching and uneven force of the cutters used in the current tobacco planting process, this paper designs a special ditching cutter for the tobacco planting ditch fertilizer machine. In order to make the cutter force uniform and labor-saving, the line segment ratio and included angle of the ditching tool ridge curve (second-order Bezier curve) are the changing factors. The parameters of the ditching tool are optimized through EDEM simulation analysis, and the current ridge curve line segment is obtained through EDEM simulation analysis and field test verification. The ratio is 1:3, when the included angle is 150°, the uniform force of the ditching tool is the best and it can open a groove with a preset width of 100mm and a depth of 100mm (adjustable depth), and the ditching pattern is regular and stable.
Aiming at addressing the problem of low mechanization of filling and transporting citrus seedling pot in China, a new type of seedling pot filling and transporting machine with 120 pots at a time was designed. Based on the study of the flow characteristic of the seedling substrate, key components of the filling and transporting machine, such as blanking mechanism, transmission mechanism, flap mechanism, and steering mechanism were designed. The effects of the opening width of the hopper, the rotating speed of the stirring shaft, the moisture content of the seedling substrate, and the forward speed of the transporting device on the filling effect of seedling pot were studied by the experimental method, and the optimal operation parameters were determined. The prototype tests were repeated 3 times with the best combination of parameters. The running of the prototype was stable. The number of filling bowls was 120, and the average filling time was about 40 s. The machine was in good condition for loading and unloading. The seedling pots were arranged in order. The average filling mass was 1.881kg, which was 0.006kg different from the predicted value, the relative error was 0.32%, and the mass variation coefficient was 2.97%, which was 0.12% different from the predicted value, the relative error is 4.0%. The designed machine can provide a reference for the development and optimization of the citrus substrate filling and transporting machine.
The present study was aimed at investigating language learning strategies used by the first-year students majoring in Engineering at Thai Nguyen University of Technology in Viet Nam. The Strategy Inventory for Language Learning (SILL, version 7.0) developed by Oxford (1990) was employed in the study. The findings revealed that the overall strategy use of the students was at medium level. Specifically, metacognitive strategies were discovered to be applied at the highest frequency, whereas compensation strategies were least favored by the students. Moreover, it was found that there was a significant difference between the strategy use of male and female students regarding to memory and social strategies. Significantly, detailed statistics on each use strategy provide the teacher with useful information that serves as the basis of recommended implications.
A biphasic anaerobic process for fruit and vegetable wastes (FVW) with pig manure as co substrate in the acidogenic step and lignocellulosic packing in the methanogenic step was tested. A biphasic process starting with three days of a thermophilic acidogenic digestion, followed by a twelve days methanogenic mesophilic digestion packed with wood chips, was implemented and assessed in terms of efficiency in methane generation and content in biogas. Additionally, alkaline extraction of humic compounds from the residual waste sludge was characterized as liquid humus fertilizer. Average results for 15 days of total hydraulic retention time (HRT), showed a production of 270.3 ml of methane per gram of volatile solids (VS) with 63.5 % of them removed, this is 14 % higher than without lignocellulosic packing, while biogas content of 65.9 % of methane, 9 % higher also. On the other hand, the liquid humus obtained qualified as carbonated organic fertilizer. Even though the conversion efficiency of volatile solids achieved was moderate, the combination of the hydraulic retention time (HRT) and the yield in methane generation, permits a reduction in the size of digestion reactors and the possibility to obtain a high quality liquid biofertilizer.
In this paper, the results of an optimization study to determine the optimal gear ratio for a two-speed helical gearbox with first-stage double gear sets are presented. The objective function of the problem is the minimum bottom area of the gearbox. To solve this problem, a simulation experiment was performed. In particular, the influence of six main design parameters including the total gear ratio of the gearbox, the wheel face width coefficients of both stages, the allowable contact stress of the first and the second stages and the output torque to the optimal gear ratio of the first stage u1 has been evaluated. In addition, a regression formula to find the optimal gear ratio u1 was given.