Research in Agricultural Engineering, 2010 (vol. 56), issue 2
Influence of engine power and shifting mode on energy-performance parameters of tractor's set
J. Čupera, T. Šmerda
Res. Agr. Eng., 2010, 56(2):47-52 | DOI: 10.17221/29/2009-RAE 
The aim of the paper is to assess the impact of engine power and shifting mode on the parameters of a tractor used in transport operation. To meet the objective, measurements were performed with three tractors of the Case IH product line with different maximum power and with the same trailer and load that crossed a track with 21,8 km of distance. The record files saved following values: altitude, time of trip, tractor velocity, hour fuel consumption, engine speed, actual engine torque, fuel temperature, and position. The measurement results clearly show the unsuitability of aggregation of a tractor in higher performance category, resulting in the increase...
Design of hoppers using spreadsheet
C.O.C. Oko, E.O. Diemuodeke, I.S. Akilande
Res. Agr. Eng., 2010, 56(2):53-58 | DOI: 10.17221/30/2009-RAE
This paper presents a spreadsheet add-in for the design of mass flow conical and wedge hoppers. The Jenike's hopper design charts for mass flow were curve fitted. The relationships obtained were used together with other relevant expressions to develop an add-in tool for the determination of the pertinent hopper design parameters (exit size, mass flow rate, semi-included angle, flow factor, and critical applied stress) in the Microsoft Excel environment. The add-in was tested with experimental data, and results obtained were in agreement with those obtained in the literature.
Dimensioning of the bonded lap joint
M. Müller, D. Herák
Res. Agr. Eng., 2010, 56(2):59-68 | DOI: 10.17221/35/2009-RAE
Bonded joint is a complex assembly, which creation and following use is limited by a range of factors. The primary factors are the properties of the bonded material and of the adhesive. The stress distribution in the bonded joint is substantially influenced by the bonded joint geometry and by the deformation characteristics. Laboratory experiments are intent on the above mentioned influences for bonded lap joints, which are very used in practice. The geometrical parameters of bonded joints are substantial for the constructional parameters and for costs determination. At the lower lapping length the failure of the bonded joint occurs and the maximum...
Modeling of heat and entropy sorption of maize (cv. Sc704): neural network method
R.A. Chayjan, M. Esna-Ashari
Res. Agr. Eng., 2010, 56(2):69-76 | DOI: 10.17221/37/2009-RAE
Equilibrium moisture content of maize affects its values of dehydration heat and entropy. Precise prediction of heat and entropy with regard to its equilibrium moisture content is a simple and fast method for proper estimation of energy required for dehydration of maize and simulation of dried maize storage. Artificial neural network and thermodynamic equations for computation of maize heat and entropy of sorption were used, as a new method. The artificial neural network method for prediction of the equilibrium moisture content of maize was utilized. The heat of sorption of maize is predicted by a power model. After well training of equilibrium moisture...
Functional performance of a vertical-shaft centrifugal palm nut cracker
M.C. Ndukwu, S.N. Asoegwu
Res. Agr. Eng., 2010, 56(2):77-83 | DOI: 10.17221/28/2009-RAE
A vertical-shaft centrifugal palm nut cracker was presented and evaluated. The cracker efficiency and kernel breakage ratio are some of the most important parameters for evaluating the cracker performance. From the result of this work, the two parameters are function of cracking speed, moisture content and feed rate. The result showed that for the lowest speed of 1,650 r/min, and the highest feed rate of 880 kg/h and for all moisture contents, the cracking efficiency was not up to 65%, therefore the efficiency increases with an increase in machine speed and a decrease in feed rate. The kernel breakage ratio ranged from 0-0.18 (0-18%) for all feed rates...