Research in Agricultural Engineering, 2013 (vol. 59), issue 2
Experimental model of ammonia elimination by ozone in the airOriginal Paper
P. Hutla, B. Petráčková, J. Kára
Res. Agr. Eng., 2013, 59(2):39-45 | DOI: 10.17221/54/2012-RAE 
Experimental device was created to model stable atmosphere. The device consists of the glass vessel filled with air. Volume of the vessel is 30 litres. The ammonia concentration is similar to stable air. Amount of ozone in 2.4 mg was added and subsequently weight loss of ammonia was measured. Measurements were performed at different temperatures (20°C, 45°C) and different air humidity. The observed ratio of reacting ozone and ammonia is 5.2:1. It was also found, that this ratio is practically independent of temperature and relative humidity that occur in a stable environment. The results are the basis for the design of ozone air purification technology.
Degradation of polymer particle systems in agrocomplexOriginal Paper
P. Valášek, M. Brožek
Res. Agr. Eng., 2013, 59(2):46-50 | DOI: 10.17221/12/2012-RAE
One of the possibilities of recycling waste from blasting processes is the application of these secondary materials in polymeric matrix, where the primary material is replaced with the secondary one. By this quite specific recycling process a new material arises - polymeric particle composite. It is a case of two phase system, properties of which are defined by the mutual interaction of single components. One of the possible applications of these systems is agrocomplex. Systems used in agrocomplex environment can be subjected to specific influences, which change their mechanical properties in some time - degradation occurs. This contribution occupies...
Comparison of three methods for rendering plant fat transesterificationOriginal Paper
A. Prošková, J. Kučera, Z. Kopicová, L. Škarková
Res. Agr. Eng., 2013, 59(2):51-55 | DOI: 10.17221/19/2011-RAE
Three most frequently used methods for fat transesterification were compared using rendering plant fat (RPF) as model. Acid-catalysed transesterification was found to be the most effective (conversion 90%) at optimum conditions (fat: methanol ratio 1:10, sulphuric acid amount of 2% v/v, temperature 95°C). Base-catalysed transesterification of RPF on the other hand, results in much lower conversion (45%) at optimum conditions (fat:methanol ratio 1:20, NaOH amount 8% w/v, optimum temperature 95°C). The difference is done (among others) by the fact that RPF has high concentration of free acid (high acidity number) compared with the fats usually used for...
Evaluation of work quality of the green peas harvester Ploeger EPD 490Original Paper
P. Findura, J. Turan, J. Jobbágy, M. Angelovič, O. Ponjican
Res. Agr. Eng., 2013, 59(2):56-60 | DOI: 10.17221/5/2012-RAE
Machines for harvesting vegetable must reliably collect the given type of vegetables at various climatic conditions, and with adequate performance, quality and low losses. Machines for harvesting of green peas must be sufficiently reliable and handling must be simple. The criteria of their work are based on harvested product quality, and the size of losses incurred depends on the rate of release of pods from the plants and on the release of grains from pods. The size of loss of grain and pods in the field and grain damages in the storage tank is directly proportional to the appropriately selected operating mode of the machine. Resistance to the damage...
Application of hard surfacing for repairing of agricultural partsOriginal Paper
J. Viňáš, J. Brezinová, A. Guzanová, M. Kotus
Res. Agr. Eng., 2013, 59(2):61-67 | DOI: 10.17221/4/2012-RAE
The contribution deals with the analysis of claddings quality realised by shielded metal arc welding with covered electrodes. For cladding, covered basic electrodes marked as E Z Fe 8 EN 14700 and E Z Fe 15 EN 14700 were used. The third type of electrode was experimentally made basic electrode with operating name EW11 (wolfram content 11%). New share made of C50R EN10083/1-98 was used as reference material. Quality of repairing deposits was evaluated by micro hardness measuring and by metallographic analysis of claddings and base material. Wear resistance of claddings was determined by weight loss during abrasive wear test by wading in following loose...
Analysis of the model application of mechanical equipment for hydrothermal treatmentOriginal Paper
P. Junga, T. Vítěz, P. Mach, P. Trávníček
Res. Agr. Eng., 2013, 59(2):68-73 | DOI: 10.17221/3/2012-RAE
Two model applications of mechanical equipment for hydrothermal treatment were analysed. Alternative 1 consisted of a treatment output of 2,000 Mg of processed material, the annual compost production of 1,000 Mg, total capital expenditure of 15,838,000 CZK, unit capital expenditure of 7,919 CZK per 1 Mg of processed material and annual operating expenses of 1,300,000 CZK. The net present value (NPV) is 1,482,800 CZK, the internal rate or return (IRR) totals 7.6% and the discounted payback time (Tsd) is 16.9 years. Alternative 2 employing the mechanical equipment proved a potential increase in the treatment output...