Research in Agricultural Engineering, 2016 (vol. 62), Special Issue
The effect of granulometric structure and moisture of fertilizer on its static strengthOriginal Paper
Macák M., Krištof K.
Res. Agr. Eng., 2016, 62(10):S1-S7 | DOI: 10.17221/31/2016-RAE 
During the load of vertical static force the strength limit of individual fertilizer particles was studied in relation to the fertilizer moisture content and granulometric composition. The experiment was conducted for the fertilizer damage at the different level of fertilizer moisture content and particle size groups. The result of the first part indicates the need to point out the differences of static strength between prilled and granular fertilizers. Both types of prilled fertilizers reached from 3 to 8 times lower values of static strength than standard granular fertilizers. The theses above point out the need for more caution during manipulation,...
Monitoring of selected emissions of internal combustion engineOriginal Paper
M. Králik, J. Jablonický, Z. Tkáč, Ľ. Hujo, D. Uhrinová, J. Kosiba, J. Tulik, R. Záhorská
Res. Agr. Eng., 2016, 62(10):S66-S70 | DOI: 10.17221/72/2015-RAE
The paper deals with the possibility of appropriate measurement and evaluation of emissions of nitrogen oxides. Development of exhaust systems which captures the solid particles emitted from engine, lost an objective assessment of the emission status of the diesel engine of agricultural tractor. Therefore, it is necessary to find a new method of measuring and quantifying the emission state of the diesel engine by measuring emissions, which should be economic and time-saving, but especially universal and sufficiently precise. The selected method should also provide sufficient information on such emissions that are subject to approval but they are not...
Biomass combustion emissionsOriginal Paper
V. Kažimírová, R. Opáth
Res. Agr. Eng., 2016, 62(10):S61-S65 | DOI: 10.17221/69/2015-RAE
The paper deals with gaseous emissions generated in biomass combustion in water boilers. It provides results of analyses of gaseous emissions and boiler efficiency in combustion of branches of apple trees from spring pruning, spruce cuttings and corn cobs obtained from kernel harvest. Measurements were done in laboratory conditions. Average CO emission values observed in combustion were from 334.7 to 650.18 mg/m3 and average NOx emission values were low, between 50.1 and 157.2 mg/m3. Boiler efficiency in applewood combustion was lower - this was caused by its higher moisture.
Hazard analysis in operating of the post-harvest linesOriginal Paper
M. Prístavková, M. Žitňák, J. Lendelová
Res. Agr. Eng., 2016, 62(10):S53-S60 | DOI: 10.17221/52/2016-RAE
The aim of this study is to evaluate the hazards in operating post-harvest lines in an agricultural organization, with emphasis on pre-cleaning and drying of grain. The paper deals with a description of technology of pre-cleaning and drying grain. Risk assessments at post-harvest line were processed by using the point method. The point method is used to review the hazards for working positions in terms of safety at work. This work identifies threats, proposes measures and solutions to eliminate or minimize the consequences of each risk. Evaluations of the hazards are processed before and after the measures were taken. Based on the results, it can be...
Testing of property changes in recycled bedding for dairy cowsOriginal Paper
J. Lendelová, M. Žitňák, M. Bošanský, M. Šimko, P. Piterka
Res. Agr. Eng., 2016, 62(10):S44-S52 | DOI: 10.17221/45/2016-RAE
The aim of this study was to analyse the change of the characteristics of different types of organic bedding in deepened stall base cubicles for dairy cows. The research was carried out in barn 1 using separated raw manure solids, in barn 2 using drum composted manure solids and for comparison a barn 3 was chosen, which used traditional straw as a bedding material. Dry matter of separated raw manure and drum composted recycled manure solids in sample 1 collected after 2-3 hours of bedding acclimatization in the stable were lower (P < 0.05) compared with sample 3 collected 2-3 hours before the new bedding was spread, but dry matter of straw...
The effectiveness of heating of housing unit by renewable energy sourceOriginal Paper
J. Jobbágy, K. Krištof, M. Andacký
Res. Agr. Eng., 2016, 62(10):S34-S43 | DOI: 10.17221/44/2016-RAE
The paper is aimed at pointing out possibilities of using of dendromass for heating. The object of interest was heating of housing units with 75.27 m2 of total area. The average value of dendromass moisture was 17.71%. The inserted fireplace Nordica Focolare 70 with a nominal output of 9 kW was used as a heat source. For temperature measurement, a non-contact infrared thermometer GM 900 was used. The total heat loss transferred through walls of housing unit (heat loss through thermal bridges and ventilation losses) were calculated at the value of 176.26 W/K. Based on the results of samples moisture the net calorific value of one kilogram...
The device of magnetic processing of water for boiler greenhouseOriginal Paper
S.N. Antonov, S.Z. Gabriyelyan, M.A. Mastepanenko, E.B. Zorina, L. Nozdrovický
Res. Agr. Eng., 2016, 62(10):S27-S33 | DOI: 10.17221/41/2016-RAE
The most part of the heat power equipment in agriculture is maintained with infringement of requirements in rules of technical operation. The scum that does not leave from heating surfaces reduces copper efficiency and increases fuel consumption. Chemical ways of ecological water preparation are not safe and are expensive. Magnetic water preparation has a number of advantages in this way, one of which is the possibility not only to prevent scaling, but also to remove earlier scum. Existing devices of water magnetic processing has a basic deficiency - presence of narrow slot hole backlashes in which the processing is performed. Thus, the productivity...
Impact of shelter on daylight in the stables for dairy cowsOriginal Paper
M. Balková, R. Záhorská
Res. Agr. Eng., 2016, 62(10):S21-S26 | DOI: 10.17221/36/2016-RAE
The aim of the measurement was to assess the illuminance values and values of daylight factor in two stables for dairy cows that have the same technology layout. The difference between the stables was a shelter on the side of one of them. Measurements were made halfway through the stables including edge portions with cubicle and central parts with feed passage, above which is skylight. From the measured values of illuminance and calculated values of daylight factor, it can be seen that the effect of roof skylight is significant in terms of daylight. At the same time, they show how shelter affects daylight in the stable. The difference in values in...
Ideal cycle of combustion engine with natural gas as a fuelOriginal Paper
I. Vitázek, J. Klúčik, J. Jablonický, P. Vereš
Res. Agr. Eng., 2016, 62(10):S14-S20 | DOI: 10.17221/35/2016-RAE
The aim of the paper is to present a detailed methodology of calculations of parameters of an ideal working cycle of spark-ignition combustion engine. Natural gas in the form of compressed natural gas (CNG) was used as a fuel. A theoretical ideal cycle is currently described in simplified way. The paper introduces calculations considering excess air, residual space in the cylinder of the engine and the course of properties of gases in dependence on temperature. The thermodynamics of ideal gas mixture was used. A computer program for clear, quick and accurate calculations of this relatively complicated system of relations was designed. The presented...
Thermodynamics of combustion gases from biogasOriginal Paper
I. Vitázek, J. Klúčik, D. Uhrinová, Z. Mikulová, M. Mojžiš
Res. Agr. Eng., 2016, 62(10):S8-S13 | DOI: 10.17221/34/2016-RAE
Biogas as a respected source of renewable energy is used in various areas for heating or in power cogeneration units. It is produced by anaerobic fermentation of biodegradable materials. The utilization of biogas is wide - from process of combustion in order to obtain thermal energy, combined heat and power production, gas combustion engines, micro turbines or fuel cells up to trigeneration. Biogas composition depends on the raw material. The aim of this paper was to develop a new methodology; according to this methodology, by means of gas mixture thermodynamics and tabular exact parameters of individual gaseous components, all the necessary thermodynamic...