Research in Agricultural Engineering, 2009 (vol. 55), issue 3
Effects of moisture content, loading rate, and grain orientation on fracture resistance of barley grain
H. Tavakoli, S.S. Mohtasebi, A. Rajabipour, M. Tavakoli
Res. Agr. Eng., 2009, 55(3):85-93 | DOI: 10.17221/6/2009-RAE 
Force and deformation curves of agricultural materials must be provided for the proper design of harvesting and processing machineries. In this research, the fracture resistance of barley grain was measured in terms of the grain rupture force and energy. In this study, 8 treatments were performed as a randomised complete block design with 10 replications. The barley grains were quasi-statically loaded in horizontal and vertical orientations with the moisture content at four levels: 7.34, 12.11, 16.82, and 21.58% dry basis, and loading rates at two levels: 5 and 10 mm/min. Based on the results obtained, the force required for initiating the grain rupture...
Bearing capacity and corrosion weight losses of the bonded metal joints in the conditions of Indonesia, North Sumatra province
D. Herák, M. Műller, J. Karanský, O. Dajbych, S. Simanjuntak
Res. Agr. Eng., 2009, 55(3):94-100 | DOI: 10.17221/5/2009-RAE
: The article is focused on the analysis of the bonded metal joints capacity and corrosion weight losses in the conditions of equatorial Indonesia - North Sumatra province. For the purpose of the given article, the province was divided into three main climatic zones: Medan, Balige, Pagarbatu, where the dependence was observed of the bonded joints capacity on the duration of the weather exposure. The joints life and their further usability were predicted based on the analyses of the measured values.
Effect of abrasive particle size on abrasive wear of hardfacing alloys
R. Chotěborský, P. Hrabě, M. Müller, J. Savková, M. Jirka, M. Navrátilová
Res. Agr. Eng., 2009, 55(3):101-113 | DOI: 10.17221/24/2008-RAE
Hardfacing is one of the most useful and economical ways to improve the performance of components submitted to severe wear conditions. This study has been made for the comparison of microstructure and abrasion resistance of hardfacing alloys reinforced with chromium carbides or complex carbides. The hardfacing alloys were deposited onto ČNS EN S235JR low carbon steel plates by the gas metal arc welding (GMAW) method. Different commercial hardfacing electrodes were applied to investigate the effect of abrasive particle size on abrasive wear resistance. The abrasion tests were made using the two-body abrasion test according to ČSN 01 5084 standard, abrasive...
Determining of moisture diffusivity and activation energy in drying of apricots
E. Mirzaee, S. Rafiee, A. Keyhani, Z. Emam-Djomeh
Res. Agr. Eng., 2009, 55(3):114-120 | DOI: 10.17221/8/2009-RAE
In this study, Fick's second law was used as a major equation to calculate the moisture diffusivity for apricot fruit with some simplification. Drying experiments were carried out at the air temperatures of 40, 50, 60, 70, and 80°C and the drying air velocity of 1, 1.5 and 2 m/s. The experimental drying curves showed only a falling drying rate period. The calculated value of the moisture diffusivity varied from 1.7 × 10-10 to 1.15 × 10-9 m2/s for apricot fruit, and the value of activation energy ranged from 29.35 to 33.78 kJ/mol at different velocities of air.
The effect of tractor supply in Iran agriculture from a macro plan point of view
M. Ghadiryanfar, A. Keyhani, A. Akram, S. Rafiee
Res. Agr. Eng., 2009, 55(3):121-127 | DOI: 10.17221/28/2008-RAE
The aim of this study was to investigate the effect of the tractor supply on agricultural yield from a macro plan perspective. The required information was obtained from the Institute of Agricultural Machinery Extension and Ministry of Jihad-e-Agriculture of Iran. Regarding the number of tractors distributed, the maximum number of tractors distributed in Iran was 37 996 in 1983. The effect of this distribution pattern on the crops yields and planted area was investigated for a thirteen-year period from 1983 to 1996. The results showed that these tractors had significant effects on the crops yields and planted area. Also it was inferred that the power...