Research in Agricultural Engineering, 2011 (vol. 57), Special Issue
Analysis of the relations between some physicalindicators of market eggs
R. Gálik, Z. Poláková, Š. Boďo, M. Denker
Res. Agr. Eng., 2011, 57(10):S1-S6 | DOI: 10.17221/54/2010-RAE 
The paper discusses the relations between some physical indicators of market eggs of laying hens housed in conventional and enriched cage batteries. The measured results were evaluated by the multiple regression dependence method. They show that in the case of both the conventional as well as the enriched cages a statistically significant dependence exists between the eggshell deflection (dependent variable) and thickness, or the force needed for the eggshell destruction (independent variable). The respective P values are given in brackets (0.002 < 0.05; 0.03 < 0.05; 1.16 × 10-10 < 0.05; 8.31 × 10-4 < 0.05);...
Using satellite navigation for seeding of wide-row and narrow-row crops
M. Macák, M. Žitňák, L. Nozdrovický
Res. Agr. Eng., 2011, 57(10):S7-S13 | DOI: 10.17221/6/2011-RAE
The present paper is aimed at the use of satellite navigation of field machinery during seeding, this operation belonging to the most important field practises. Our attention was focused on the determination of the accuracy of the satellite navigation system based on using the correction signal real-time kinematic and its correct application for planting a wide-row crop (sunflower) and seeding a narrow-row crop (spring barley). The aim of the field experiment was also to specify the level of the necessary accuracy of satellite navigation systems during planting and seeding. The length of seeding/planting equipment was confronted with the accuracy of...
Shadow method for the evaluation of surface created by hydroabrasive dividing of materials
J. Valíček, M. Kadnár, P. Hlaváček, J. Rusnák, S. Hloch, M. Zeleňák, M. Řepka, M. Kušnerová, J. Kadnár
Res. Agr. Eng., 2011, 57(10):S69-S73 | DOI: 10.17221/49/2010-RAE
The contribution deals with the analysis of the optical data obtained from the surfaces generated by hydroabrasive dividing of materials. The samples of different materials were prepared at the Academy of Sciences of the Czech Republic. The comparison of further results performed between the commercial contact profilometer HOMMEL TESTER T8000 and the contactless shadow method developed included its calibration. On the basis of the optical data analysis, the results evaluated especially the height irregularities of the surface topography caused by hydroabrasive cutting planes. The evaluation of the surface topography generated by abrasive waterjet was...
Material machining for friction knots of moving parts for agricultural machines
J. Žitňanský, J. Žarnovský, R. Mikuš, I. Kováč, Z. Andrássyová
Res. Agr. Eng., 2011, 57(10):S61-S68 | DOI: 10.17221/21/2011-RAE
The study deals with the effect of the cutting parameters such as the cutting speed, feed and cooling on the quality of machined surfaces in the process of hole drilling for the sliding bearings used in agricultural technique. This effect has been studied on various metals such as copper, brass, dural and leaded bronze, which are commonly used for their friction knots of the moving parts for agricultural machinery. The results suggest the use in the design of collection parts, scything strips, as well as lifting equipment of agricultural technique, where particular linear and rotary movements of the friction parts are slow, as well as for the design...
Measurement of titanium surface roughness created by non-conventional cutting technology
J. Rusnák, M. Zeleňák, J. Valíček, M. Kadnár, S. Hloch, P. Hlaváček, M. Kušnerová, R. Čep, J. Kadnár
Res. Agr. Eng., 2011, 57(10):S57-S60 | DOI: 10.17221/48/2010-RAE
The paper evaluates the surface roughness quality of the titanium samples created by abrasive waterjet (AWJ) and by CO2 laser beam cuttings. The introduction describes the principle of the mechanical (contact) method as well as the roughness parameters used for the experiment results evaluation. The following parts summarise the experimental conditions and the measurement methodology. The emphasis of this work is laid on the comparison of machined surfaces final quality for the selected traverse speeds.
Influence of welding method on microstructural creation of welded joints
P. Čičo, D. Kalincová, M. Kotus
Res. Agr. Eng., 2011, 57(10):S50-S56 | DOI: 10.17221/57/2010-RAE
This paper is focused on the analysis of the welding technology influence on the microstructure production and quality of the welded joint. Steel of class STN 41 1375 was selected for the experiment, the samples were welded by arc welding including two methods: a manual one by coated electrode and gas metal arc welding method. Macro and microstructural analyses of the experimental welded joints confirmed that the welding parameters affected the welded joint structure in terms of the grain size and character of the structural phase.
The comparison of biodegradable hydraulic fluid with mineral oil on the basis of selected parameters
R. Majdan, J. Kosiba, J. Tulík, D. Kročková, V. Šinský
Res. Agr. Eng., 2011, 57(10):S43-S49 | DOI: 10.17221/7/2011-RAE
The paper presents a comparison of two fluids quality. The first one was mineral oil type UTTO which is commonly used in the transmission and hydraulic systems of agricultural tractors. The second one tested was biodegradable hydraulic fluid type ERTTO which could replace the toxic mineral oil. Both fluids were tested under the same test conditions using a special test device. The selected parameters of the hydrostatic pump were evaluated. The tests were evaluated according to the parameters describing the technical state of the hydrostatic pump as follows: flow efficiency, decrease of flow efficiency and cleanliness level of the fluid tested. This...
Operating parameters and emission evaluation of tractors running on diesel oil and biofuel
D. Müllerová, M. Landis, I. Schiess, J. Jablonický, M. Prístavka
Res. Agr. Eng., 2011, 57(10):S35-S42 | DOI: 10.17221/51/2010-RAE
This work is aimed at the evaluation of the operating parameters and emission of two tractors: Hürlimann H-488 DT and Hürlimann XB Max 100. The measurements were done on a test bench in the laboratory of the Agroscope Reckenholz-Tänikon Research Station ART, Ettenhausen, Switzerland during February 2010. The goal of this paper was to evaluate the operating parameters of the two models of tractors by using classical diesel oil and biofuel, as well as to evaluate the emission (greenhouse gases, dangerous exhaust gases and carcinogens), to make statistical analysis of the results and the conclusion about the samples used and the impact on engine parameters,...
Comparison of numerical integration methods in strapdown inertial navigation algorithm
V. Cviklovič, D. Hrubý, M. Olejár, O. Lukáč
Res. Agr. Eng., 2011, 57(10):S30-S34 | DOI: 10.17221/58/2010-RAE
The numerical mathematical theory provides a few ways of numerical integration with different errors. It is necessary to make use of the most exact method with respect to the computing power for a majority of microprocessors, because errors are integrated within them due to the algorithm. In our contribution, trapezoidal rule and Romberg's method of numerical integration are compared in the velocity calculation algorithm of the strapdown inertial navigation. The sample frequency of acceleration and angular velocity measurement was 816.6599 Hz. Inertial navigation velocity was compared with precise incremental encoder data. Trapezoidal method velocity...
Drying medium - modelling and process evaluation
I. Vitázek, J. Havelka
Res. Agr. Eng., 2011, 57(10):S24-S29 | DOI: 10.17221/55/2010-RAE
Natural gas is used as a heat source in the majority of modern drying plants in agriculture. The input gas is a mixture of natural gas and atmospheric air. With burning, the composition of this mixture changes. Drying medium is a mixture of hot combustion gases from natural gas and atmospheric air added. The thermic parameters of natural gas and atmospheric air are permanently constant. The authors present their method of the calculation of thermodynamic parameters of the drying medium. They elaborated two computer programmes in Q-Basic for the calculation related to the drying medium with temperatures in the range 100-200°C.
Evaluation of efficiency of precision irrigation for potatoes
J. Jobbágy, J. Simoník, P. Findura
Res. Agr. Eng., 2011, 57(10):S14-S23 | DOI: 10.17221/47/2010-RAE
The objective of the presented paper was to verify in practice the methods of precision irrigation, defined theoretically, under the employment of reel hose irrigation machines. The surface area of the field was 22 ha. The basic soil hydrological coefficients were measured in 19 monitoring points, specifically the field capacity and the wilting point. The field capacity ranged between 28.83% and 32.11% by vol., and the wilting point was in the interval between 8.40% and 12.40% by vol. At the conclusion, the soil moisture as a factor decisive for determining the irrigation rate was measured in these monitoring points. The irrigation rate ranged from...
Analysis of wear resistent weld materials in laboratory conditions
M. Kotus, Z. Andrássyová, P. Čičo, J. Fries, P. Hrabě
Res. Agr. Eng., 2011, 57(10):S74-S78 | DOI: 10.17221/56/2010-RAE
The aim of the study was the evaluation of the suitability of using filler surfacing materials in abrasion resistant layers according to their material and tribology features. Laboratory analysis of the selected materials consisted of the tests of hardness, microstructure and wear resistance determination. The abrasive wear resistance was defined according to the standard STN 01 5084. On the basis of the results obtained, we can state that using the hard-facing for the background is tenable for the purpose of wear amount decrement where the abrasive wear prevails.