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
To counter climate change and achieve sustainable agriculture goals, farmers must follow sustainable agriculture practices. Several factors have been described as influencing farmers' decisions to adopt sustainable agricultural practices, but adoption remains poor, especially in Africa. Based on the theory of planned behavior extended with constructs from the Norms Activation Theory, we investigate the adoption of sustainable agricultural practices by cocoa farmers in Côte d'Ivoire. The data was derived from a survey of 570 cocoa farmers conducted in 2020. We used structural equation model (SEM) to look for correlations between variables. The results indicate that subjective norm, personal norm, attitude, and perceived behavioral control are significantly positively correlated with farmers' Intention toward Sustainable Agricultural Practices and that farmers' personal ecological norm is affected both by the Awareness of the consequences of their action and their subjective norm when their attitude is only affected by Awareness of the consequences.
This study presents analysis of nonlinear vibration of functionally graded (FG) micro-beams subjected to axial compressive load and resting on elastic foundation in framework of the Euler-Bernoulli beam theory (EBT) and nonlocal strain gradient theory (NSGT). The FG micro-beam composed of two materials including metal and ceramic is considered in which, the material properties change according to a simple power law of the coordinate in the thickness direction. The expressions of nonlinear frequencies of the FG micro-beams with simply-supported (S-S) and clapmed-clamped (C-C) boundary conditions are obtained in the analytical forms. The accuracy of the obtained results for the FG micro- beams is verified by comparing the obtained solutions with the published ones. Influences of some important parameters on the nonlinear vibration responses of the FG micro-beams are examined and discussed.
This study proposes a nonlinear dynamic model for a novel hydro-pneumatic suspension system of an earth-moving equipment based on traditional dynamic model with changing the properties of the elastic and damping elements with an auxiliary air chamber. And then, a quarter-vehicle dynamic model of suspension system is set up to evaluate and compare vehicle ride comfort performance between novel hydro-pneumatic suspension system and traditional hydro-pneumatic suspension system under the different operating conditions of vehicle via the root mean square (r.m.s) acceleration responses of vehicle body (awz) according to international standard ISO 2631-1:1997 and power spectral density (PSD) acceleration responses of vehicle body. The numerical simulation results indicate that awz values and peak amplitude values with the novel hydro-pneumatic suspension system respectively reduce in comparison with the traditional hydro-pneumatic suspension system. Especially, vehicle ride comfort performance with novel hydro-pneumatic suspension system significantly improves in the low frequency region of from 0.5 Hz to 10 Hz when vehicle moves on from ISO class C road surface at speed of 40km/h and full load. Finally, the different operating conditions of vehicle are chosen to verify and evaluate the effectiveness of the novel hydro-pneumatic suspension system in comparison with the traditional hydro-pneumatic suspension system. The obtained results indicate that the proposed system significantly performs better than the traditional hydro-pneumatic suspension system does in terms of ride comfort of vehicle.
The purpose of this study is to analyze the ride performance of a mining dump truck with hydro-pneumatic suspension system (HPSs). A mathematical model of hydro-pneumatic suspension strut with two oil chambers and one gas chamber is set up to determine its vertical force. And then a three-dimensional vehicle- road coupled dynamic model of a mining dump truck with 11 degrees of freedom under random road surface roughness is set up to analyze the effectiveness of HPSs in the direction of the ride comfort of vehicle. The time domain and power spectral density (PSD) of acceleration responses of the vertical driver’s seat, and the cab pitch and roll angles of a mining dump truck are chosen as objective functions to analyze the vehicle ride comfort performance of HPSs. Finally, the ride comfort performance of the HPSs under different operating conditions is analyzed respectively through objective functions. The obtained results indicate that the ride performance of a mining dump truck with HPSs are significantly improved under large amplitude excitation region of road surface roughness. Especially, the ride performance of a mining dump truck with HPSs has improved significantly at the low frequency region from 4 Hz to 10Hz in the vertical direction of driver’s seat and the cab pitch and roll angles under survey conditions.
This study proposes an analytical study in ride performance of a hydraulic cab mount system (HCMs) with the orifice and the annular orifice for a wheel loader under larger amplitude excitation of road surface roughness. First, a nonlinear dynamical model of hydraulic mount with the piecewise damping characteristic is set up to determine the vertical nonlinear force of hydraulic cab mount. And then, a half-vehicle dynamic model of a wheel loader is offered to analyze and compare the performance of hydraulic cab mount system and rubber cab mount system (RCMs) in terms of ride performance. Time domain and frequency domain acceleration responses of the vertical driver’s seat and cab pitching angle are selected as the objective functions to assess and compare HCMs performances. The study results indicate that the RMS values of acceleration responses of the vertical driver’s seat and cab pitching angle with HCMs respectively reduce by 38.16% and 29.26% in comparison with those of RCMs, and the power spectral density (PSD) value of acceleration response of the vertical driver’s seat with HCMs reduce by 55.94% in comparison with the ones of RCMs at frequency about 5Hz when vehicle moves on ISO class C road surface at the vehicle speed of 15km/h and empty load. Finally, the ride performance of HCMs in comparison with that of RCMs under various large amplitude of road surface roughness indicates that the RMS values of acceleration responses of the vertical driver’s seat and cab pitching angle respectively reduce by 30.87% and 25.70% when vehicle with full load moves on ISO class E road surface at speed of 10km/h, which improves more comfort performance under larger amplitude excitation.