Research in Agricultural Engineering, 2015 (vol. 61), issue 4
Influence of temperature on vacuum drying characteristics, functional properties and micro structure of Aloe vera (Aloe barbadensis Miller) gelOriginal Paper
R.K. Jha, P.K. Prabhakar, P.P. Srivastav, V.V. Rao
Res. Agr. Eng., 2015, 61(4):141-149 | DOI: 10.17221/13/2014-RAE 
Aloe vera possesses therapeutic, antioxidant and some other functional properties. These properties may be affected by processing operations. The present study investigated the influence of operating temperature on vacuum drying characteristics, functional properties and the inner solid structure of the fresh aloe vera gel. The gel was dried at a constant pressure of 720 mm Hg in the drying chamber at varying temperature of 30-60°C. The experimental data of moisture ratio of Aloe vera were used to fit different models and the effective moisture diffusion coefficients and activation energy were also calculated. The Page model was found to be the best...
Thermal and physical properties modelling of terebinth fruit (Pistacia atlantica L.) under solar dryingOriginal Paper
M. Kaveh, R. Amiri Chayjan, M. Esna-Ashari
Res. Agr. Eng., 2015, 61(4):150-161 | DOI: 10.17221/45/2013-RAE
A laboratory solar dryer was used to study terebinth fruit drying. Two solar collectors were adjusted in east-west directions with the angle of 45°. Initial moisture content of terebinth fruit was dried under natural and forced airflow. In order to predict terebinth moisture content during drying process five mathematical models were used. Colour change and shrinkage of the terebinth samples were calculated. Results showed that the Page model had the best performance in moisture content prediction of terebinth samples. Effective moisture diffusivity of terebinth fruit was increased under forced convection. The lowest colour change and shrinkage of...
Wear of disc mill hammer in wet grinding processes on groundnut cake for fish feed productionOriginal Paper
O.B. Oduntan, B.O. Omitoyin
Res. Agr. Eng., 2015, 61(4):162-169 | DOI: 10.17221/67/2013-RAE
There is need to determine the wear rates of disc mill hammer used for grinding groundnut cake, a major plant protein in fish feed. This surface wear damage characterised by scoring, cutting, deep grooving and gouging on a metal surface leads to high costs of production. The hammer wear rate was carried out using disc mill for different combinations of processing conditions: disc speed of 2,175, 3,900 and 4,350 rpm; screen size of 1.0, 2.0 and 3.0 mm; moisture contents of 12, 14 and 16% w.b. at 300 operating hours. Response Surface Method was used to optimize the operating variables. The wear rate was found to increase as the moisture content of the...
Pyrolysis of sandbox (Hura crepitans) shell: Effect of pyrolysis parameters on biochar yieldOriginal Paper
F.A. Ola, S.O. Jekayinfa
Res. Agr. Eng., 2015, 61(4):170-176 | DOI: 10.17221/69/2013-RAE
Pyrolysis of sandbox shell was carried out with the aim of investigating the effect of pyrolysis parameters on the pyrolysis process and identifies production conditions for the yield of biochar. Parameters investigated were heating temperature (400, 500 and 600°C), heating time (10, 20, and 30 min) and particle size of feedstock (0-1.0, 1.0-2.5 and 2.5-5.0 mm) in a laboratory batch pyrolysis process. The experiment was designed by applying response surface methodology through a three-factor full factorial design. The quadratic polynomial model obtained explains adequately the modelled response with coefficient of correlation, R2...
Influence of loading speed on a change of parameters of adhesive bonds based on cyanoacrylatesOriginal Paper
M. Müller
Res. Agr. Eng., 2015, 61(4):177-182 | DOI: 10.17221/15/2015-RAE
The paper deals with a behaviour of adhesive bonds created by means of quick-setting adhesives at different speeds of a loading. The aim of the research was to simulate a change of a bearing capacity of the adhesive bond at marginal limits foregoing the bond destruction. Application of quick-setting adhesives based on cyanoacrylates is considerably spread in a technical practice. Its advantage is speed of a hardening process. A fast creation of a bond and a possibility of fast manipulation with the adhesive bond are connected with it. The manipulation strength of the adhesive bond is reached in a few seconds. The aim of the research is to describe...