Research in Agricultural Engineering, 2013 (vol. 59), Special Issue
Comparison of thermal and rheologic properties of Slovak mixed flower honey and forest honeyOriginal Paper
M. Božiková, P. Hlaváč
Res. Agr. Eng., 2013, 59(10):S1-S8 | DOI: 10.17221/43/2012-RAE 
The article deals with the comparison of thermal and rheologic properties of two types of honey - mixed flower honey and forest honey made in Slovak Republic. All honey parameters were measured during temperature manipulation in the temperature interval from 5 to 45°C. Two series of thermal and rheologic parameters measurements were done. Firstly samples of both types of fresh honey were measured at the beginning of storage and then the same samples of honey were measured again after one week of storage. The measuring of thermal parameters i.e. thermal conductivity, thermal diffusivity and specific heat was performed by the instrument Isomet 2104,...
Determining the guidance system accuracy with the support of a large GNSS datasetOriginal Paper
V. Rataj, J. Galambošová, M. Vašek
Res. Agr. Eng., 2013, 59(10):S65-S70 | DOI: 10.17221/60/2012-RAE
Several methods are used presently to assess the accuracy of machinery guidance systems. However, these offer a limited number of records and are time and cost consuming. As the machinery is often equipped with a monitoring system for the management purposes, these data can be used. The aim of this work was to develop and verify a method to determine the accuracy of the machinery guidance systems based on a large dataset obtained from the machinery monitoring system. The proposed method uses the transformation of global navigation satellite systems (GNSS) data into a rectangular coordinate system SJTSK (National projection system - Krovak projection)....
Selected properties of agricultural biomassOriginal Paper
V. Kažimírová, T. Brestovič, R. Opáth
Res. Agr. Eng., 2013, 59(10):S60-S64 | DOI: 10.17221/58/2012-RAE
The presented contribution deals with the quantification of moisture, combustible matter content, ash content and higher heating value of the selected types of biomass used for the heat production by direct combustion. The moisture, combustible matter, and ash contents were determined by gravimetric analysis in accordance with the established standards. The average moisture of the materials examined varied from 4.35 to 9.17%; the combustible matter content in the original samples ranged from 79.46 to 93.51%; the ash content ranged from 2.14 to 11.28%. Higher heating values of the examined types of biomass varied from 14,996 to 17,641 kJ/kg. The main...
Verification of agro-production building structures affecting the quality of indoor environment in the summer seasonOriginal Paper
Š. Pogran, T. Reichstadterová, J. Lendelová, D. Páleš, W. Bieda, M. Bošanský
Res. Agr. Eng., 2013, 59(10):S54-S59 | DOI: 10.17221/55/2012-RAE
This contribution focuses on the evaluation of the effect of aerated concrete external wall of a hall falling within the category of special-purpose agricultural buildings in terms of the phase shift of temperature oscillation. The assessment was performed by precise and approximate calculation procedures and was then compared with the results obtained from the values actually measured under the operating conditions.
I-x-w diagram of wet air and wheat grainOriginal Paper
I. Vitázek, J. Havelka
Res. Agr. Eng., 2013, 59(10):S49-S53 | DOI: 10.17221/53/2012-RAE
The authors have been working for 50 years in the research and development of drying in agriculture. In the way of drying applied, warmed air is used as the drying medium. The thermodynamics of wet air is used for the analysis of these processes of drying in the calculations and in graphic demonstrations applying an i-x diagram of wet air. This diagram does not include any information about the state of the dried material. The authors therefore enlarged this i-x diagram with the equilibrium moisture contents of the dried material. In their work, the authors present a method using this enlarged diagram and, as an example, the i-x-w diagram of wet air...
Hard machining of agricultural machines partsOriginal Paper
R. Drlička, J. Žarnovský, R. Mikuš, I. Kováč, M. Korenko
Res. Agr. Eng., 2013, 59(10):S42-S48 | DOI: 10.17221/50/2012-RAE
For the renovation and/or improvement of the surface properties of machine elements, hard facing is often used. Hard structures obtained in layers or by heat treatment achieve a hardness of up to 68 hardness (HRC) or even more. The grinding of these surfaces demands the use of processing fluids and causes sometimes changes in the surface layers structure. Hard turning can replace grinding when certain requirements are fulfilled, particularly tough machining system. Hard deposits of two weld-on materials on a sample of steel grade S235JRG1 have been turned using cemented carbide inserts with a TiAlN coating of PVD type. The surface roughness measurements...
Application of differential geometry in agricultural vehicle dynamicsOriginal Paper
J. Rédl, V. Váliková
Res. Agr. Eng., 2013, 59(10):S34-S41 | DOI: 10.17221/49/2012-RAE
This paper deals with the application of differential geometry methods to a precise calculation of the length of trajectory of an agricultural mechanism that moves on a sloping terrain. We obtained technical exciting function from experimental measurements, out of which we obtained the function of Euler's parameters by using computer processing. The processing of these parameters provided translational and angular velocities of the gravity centre of the systemic vehicle MT8-222, which performed the determined mounted manoeuvres. We obtained differential equations that describe the function of a spatial curve by the application of differential geometry...
The operation of agricultural tractor with universal ecological oilOriginal Paper
J. Kosiba, Z. Tkáč, Ľ. Hujo, B. Stančík, I. Štulajter
Res. Agr. Eng., 2013, 59(10):S27-S33 | DOI: 10.17221/48/2012-RAE
This contribution presents the results of the research into the characteristics of ecological oil labelled MOL Farm UTTO Synt in the tractor operating conditions. Biodegradable fluid was applied in the gear and hydraulic circuits of the tractor Zetor Forterra 114 41. The fluid was assessed for contamination and lubrication properties by its effect on the wear of tractor hydraulic pump during the application. The hydraulic pump was removed from the tractor at specified time intervals because of its technical condition relating to the flow efficiency. The measurements were calculated as flow efficiency with minimum environmental impact of oil on the...
Gyroscope calibration with the method of simulated identificationOriginal Paper
V. Cviklovič, D. Hrubý, M. Olejár, L. Priatková
Res. Agr. Eng., 2013, 59(10):S22-S26 | DOI: 10.17221/47/2012-RAE
The calibration of Micro-Electro-Mechanical System (MEMS) gyroscopes is important for the application in which an angle is measured. The equipment for the calibration of this sensor is not always available. In this case, the method of simulated identification can be used. Some of the conditions are: using different tracks with saving angular velocity measurements, knowledge of influencing variables with their monitoring, and knowledge of the initial and final states of the angle. Based on this information, an algorithm is designed for the correction of influencing parameters by computer equipment. In our case, offsets, gains, and cross coupling coefficients...
Effect of crop residues on CO2 flux in the CTF system during soil tillage by a disc harrow Lemken Rubin 9Original Paper
T. Šima, M. Dubeňová
Res. Agr. Eng., 2013, 59(10):S15-S21 | DOI: 10.17221/46/2012-RAE
Carbon dioxide is one of the most important greenhouse gases. Agriculture, especially soil tillage, contributes to CO2 emissions significantly. The aim of the paper was the comparison of the amounts of carbon dioxide emissions released from the soil into the atmosphere depending on the controlled traffic farming (CTF) and crop residues. Three variants of the experiment were realised: before the soil tillage, immediately after the soil tillage, and seven days after the soil tillage. The soil tillage was carried out after the harvest of winter wheat by disc harrow Lemken Rubin 9 with a tractor John Deere 8230 on the loamy soil. The monitoring...
Ammonia concentration in farrowing pens with permanent limited range of motion for lactating sowsOriginal Paper
M. Dubeňová, R. Gálik, Š. Mihina, T. Šima
Res. Agr. Eng., 2013, 59(10):S9-S14 | DOI: 10.17221/45/2012-RAE
Livestock production significantly contributes to emissions of polluting gases emissions like ammonia (NH3) and greenhouse gases. Pig production is globally responsible for about 15% of ammonia emissions. The aims of this paper were the comparison of the ammonia concentrations in the farrowing pens with permanent limited range of motion between the zones of lactating sows and piglets and the impact of the day hour on ammonia concentration in this place. Photoacoustic infrared measuring devices INNOVA were used. The average values of NH3 concentration ranged from 0.787738 ppm (0.547478 mg/m3) to 0.818091 ppm (0.568573...