Research in Agricultural Engineering, 2010 (vol. 56), issue 1
Tracked mechanism simulation of mobile machine in MSC.ADAMS/View
J. Matej
Res. Agr. Eng., 2010, 56(1):1-7 | DOI: 10.17221/9/2009-RAE 
Tracked travel mechanism is, in some cases, a significant alternative of wheeled travel mechanism. A suitability of application depends on particular work conditions, which opens the space for computer simulation. This paper is focused on possibilities of tracked vehicle simulation in MSC.ADAMS; mainly in the universal module MSC.ADAMS/View, which is not especially customized for tracked vehicle simulations. The study presents a concrete example of tracked vehicle simulation and a method of its successful realization during travel through terrain obstacle as a basic manoeuvre for evaluating of chassis properties and work ergonomy.
Exploitation of anaerobic fermentation of bio-degradable wastes
J. Kára, E. Janča, D. Herák
Res. Agr. Eng., 2010, 56(1):8-17 | DOI: 10.17221/20/2009-RAE
The paper deals with assessment of biogas yield from mixtures of Reynoutria substrates and livestock manure. The aim was to perform laboratory experiments and suggest suitable fermenter operating conditions (dry matter content, pH, share of substrate components, thermic regime) for metanogenic digestion, then to determine its quality and assess the usability of such produced biogas.
The accelerated laboratory test of biodegradable fluid type "ertto"
Z. Tkáč, R. Majdan, Š. Drabant, J. Jablonický, R. Abrahám, P. Cvíčela
Res. Agr. Eng., 2010, 56(1):18-25 | DOI: 10.17221/26/2009-RAE
The accelerated laboratory tests can evaluate the properties of new biodegradable fluids under relatively short time. These test results are the ground for the continuity of the tests under operation conditions in machine. The paper presents the test of new biodegradable hydraulic fluid type "Environmentally responsible tractor transmission oil" by designed special test device. The test evaluation was realized by technical state of concrete hydrostatic pump UD 25 which is used in tractors Zetor Forterra. This pump was loaded by cyclic pressure loading during the test with tested fluid. The evaluated parameter was flow efficiency of hydrostatic pump...
An ultrasound based technique for the determination of poultry egg quality
M. Aboonajmi, A. Akram, T. Nishizu, N. Kondo, S.K. Setarehdan, A. Rajabipour
Res. Agr. Eng., 2010, 56(1):26-32 | DOI: 10.17221/18/2009-RAE
The present study investigates the possibility of the non-destructive prediction of the main quality indices of commercial eggs by calculating the ultrasound phase velocity within the egg material. The phase velocity of the ultrasound signal in the egg material was determined by analysing the recorded ultrasound signals using the Fast Fourier Transform. Three hundred commercial eggs (Boris Brown, 33 weeks age) from the first day of egg laying were purchased from a farm and divided in two groups. The first group was kept at the room temperature (22-25°C) and the second group was kept in a refrigerator (5°C). Every week, 25 eggs from both the room and...
Modeling the mass of Iranian export onion (Allium cepa L.) varieties using some physical characteristics
R. Ghabel, A. Rajabipour, M. Ghasemi-Varnamkhasti, M. Oveisi
Res. Agr. Eng., 2010, 56(1):33-40 | DOI: 10.17221/23/2009-RAE
Mass modeling can be used for development of post-harvest equipment related to onion (Allium cepa L.) processing such as grading, packing and food production processes. There are instances in which it is desirable to determine relationships among crop physical characteristics. In this study, the mass of Iranian export onion varieties (Azarshahr and Sefide Qom) was predicted by using different physical characteristics applying linear models with three different classifications: (1) - single or multiple variable regressions of onion dimensional characteristics, (2) - single or multiple variable regressions of onion projected areas, (3) - estimating...
The influence of conductivity measurement on mechanical properties of potato tubers - Short communication
J. Blahovec, A. Yurov
Res. Agr. Eng., 2010, 56(1):41-46 | DOI: 10.17221/10/2009-RAE
Deformation curves in uniaxial compression of raw potato tuber were analyzed at Nicola and Saturna varieties. In the first part of deformation (time 1 min), some part of specimens were loaded by electric field simulating simultaneous measurement of the specimen alternating-current conductivity (three levels of voltage 1, 5, and 10 V and three frequencies 1, 10, and 100 kHz). The obtained curves were analyzed by six parameters. In five of them no differences were approved statistically (α = 0.05). Only in the case of modulus of elasticity some differences were observed; however, the differences cannot be simply explained by the influence of the...