Research in Agricultural Engineering, 2014 (vol. 60), issue 1
Effect of rapeseed methyl ester on emission productionOriginal Paper
M. Pexa, K. Kubín
Res. Agr. Eng., 2014, 60(1):1-9 | DOI: 10.17221/71/2012-RAE 
This paper describes the effect of a mixture of rapeseed methyl ester and diesel oil on emission production of tractor engine. The hydraulic dynamometer was used to load the engine of Zetor Forterra 8641 tractor over rear power take-off. The measured tractor is almost new with less than 100 h worked. The measurements were realized for several ratios of diesel oil and rapeseed methyl ester (from pure diesel to pure rapeseed methyl ester). The engine was loaded by the dynamometer in several working points which were predefined by engine speed and its torque. The production of carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen...
Analysis of using brewery mash for energyOriginal Paper
Konrád Z., Los J., Fryč J., Kudělka J.
Res. Agr. Eng., 2014, 60(1):10-16 | DOI: 10.17221/21/2013-RAE
In contrast to waste in a full sense of the word, brewery mash is not considered as waste nowadays but rather as a material for various kinds of use. It can be fed to animals or processed to produce biogas. Various scientific and state institutions conduct experiments to find other possibilities of its use. Our experiment was focused on analysing the energy potential of this material.
Decomposition of the biodiesel by-product, crude glycerol, in soilOriginal Paper
P. Dalias, P. Polycarpou
Res. Agr. Eng., 2014, 60(1):17-23 | DOI: 10.17221/1/2013-RAE
The disposal of crude glycerol, the biodiesel by-product, may become an economic or environmental problem in cases where no trading of this material is possible. This study aimed at evaluating the decomposability in soil of the unpurified glycerol fraction taken after the transesterification of oil using sodium hydroxide as a catalyst. The immediate effect of glycerol incorporation was a considerable increase in soil pH. In soil samples characterized by low biological activity this pH increase did not permit microbial development although the time lag before the growth of microorganisms feeding on glycerol was shortened after the addition of a nitrogen...
Impact of the size of nitrogen fertiliser application rate on N2O fluxOriginal Paper
T. Šima, L. Nozdrovický, K. Krištof, J. Krupička
Res. Agr. Eng., 2014, 60(1):24-29 | DOI: 10.17221/81/2012-RAE
The application rate of a nitrogen fertiliser is one of the most important factors that affect the nitrous oxide (N2O) flux. Calk ammonium nitrate with 27% nitrogen content was spread by a fertiliser spreader VICON RS-L connected with a tractor Zetor 16145 and incorporated into the soil by a power harrow Pöttinger Lion 301 six hours after spreading. Monitoring points were selected based on the size of application rate 0, 100, 200 and 300 kg/ha and were measured 7, 14, 21 and 28 days after fertiliser application and incorporation into the soil. Nitrous oxide emissions were measured by a photoacoustic field gas monitor INNOVA 1412 with a multipoint...
Effect of moisture content on some engineering properties of mahogany (Khaya senegalensis) seed and kernelOriginal Paper
N.A. Aviara, A.A. Lawal, H.M. Mshelia, D. Musa
Res. Agr. Eng., 2014, 60(1):30-36 | DOI: 10.17221/10/2012-RAE
Some engineering properties of mahogany seed and kernel were investigated and expressed as a function of moisture content. In the moisture ranges of 7.1-32% and 5.3-22% (d.b.), respectively, the seed and kernel length, width and thickness increased with increase in moisture content. One thousand seed and kernel weight increased linearly with moisture content. True density, bulk density, porosity and angle of repose of seed and kernel also increased with increase in moisture content. Static and kinetic coefficients of friction increased linearly with moisture content and varied with structural surfaces. Specific heat increased with increase in both...
Environmental degradation aspects influencing coach-working one-component epoxy adhesivesOriginal Paper
M. Müller, P. Valášek
Res. Agr. Eng., 2014, 60(1):37-43 | DOI: 10.17221/42/2013-RAE
Degradation processes act on adhesive bonds behaviour in a negative way. The aim of experiments is to set the influence of liquid contaminants on strength changes of the adhesive bonds created with the adhesive used in the area of a coach-work construction. It is presumed according to a hypothesis that the adhesives applied in the construction of traffic and electricity means are resisting to liquid contaminants. The rain water, 33% solution of the rain-water and halite and the oil were used as the degradation mediums/environments. On the basis of evaluated experiments it can be said that resultant strength of the adhesive bonds decreases in the course...