Research in Agricultural Engineering, 2014 (vol. 60), Special Issue
Effect of irrigation machines on soil compactionOriginal Paper
J. Jobbágy, P. Findura, F. Janík
Res. Agr. Eng., 2014, 60(10):S1-S8 | DOI: 10.17221/26/2013-RAE 
The analysis of soil compaction with chassis of a wide-span irrigation machine Valmont was determined. The sprinkler had 12 two-wheeled chassis (size of tyre 14.9'' × 24''). During the evaluation of soil compaction, we monitored the values of penetration resistance and soil moisture during the operation of the sprinkler. Considering the performance parameters of the pump, the sprinkler was only half of its length (300 m) in the technological operation. In this area, also field measurements were performed in 19 monitoring points spaced both in tracks and outside the chassis tracks. The analysis showed the impact of compression with sprinkler wheels....
Technical exploitation parameters of grinding rolls work in flour millOriginal Paper
R. Opáth
Res. Agr. Eng., 2014, 60(10):S92-S97 | DOI: 10.17221/41/2013-RAE
The proposed research paper analyses power consumption in grinding rolls of a flour mill. The observed mill has 15 grinding passages. The hourly efficiency of grinding roll on the first passage is 3,006.72 kg/h. The specific power consumption of individual grinding rolls ranges from 4.955 to 24.26 kWh/t. The thesis also contains results of research of grinding effects on grist. The greatest effect on grist was observed on the first grinding passage, where particle size after grinding was only 12% of the original grain size, as determined by sieve analysis. On the second through fifth passage, it was 85 to 96% (or 78 to 85% with shelling) of the original...
Elimination of ecological fluids contamination in agricultural tractorsOriginal Paper
R. Majdan, Z. Tkáč, B. stančík, R. Abrahám, I. Štulajter, P. Ševčík, M. Rášo
Res. Agr. Eng., 2014, 60(10):S9-S15 | DOI: 10.17221/27/2013-RAE
This contribution presents the elimination of pollution for ecological fluids of UTTO (universal tractor transmission oils) type in agricultural tractors. The common oil filling of the transmission and hydraulic system is polluted by residues of old fillings from attachments such as ploughs, trailers, etc. In the tractor Zetor Forterra 114 41, a newly developed synthetic ecological fluid HEPR (VDMA 24568) was applied. The oil showed pollution limits after completing 900 engine hours. For this reason, a filtration device was designed to clean mainly biodegradable fluids UTTO. On the basis of fluid application evaluation and performed filtration, it...
The effect of evaporative cooling on climatic parameters in a stable for sowsOriginal Paper
Ľ. Botto, J. Lendelová, A. Strmeňová, T. Reichstädterová
Res. Agr. Eng., 2014, 60(10):S85-S91 | DOI: 10.17221/40/2013-RAE
The aim of this study was to find out the effect of indirect evaporative cooling on microclimatic parameters in a stable for sows. A high-pressure system was used for cooling, the nozzles sprayed water into the outside air before its entering into the building. Temperature-humidity index during cooling was higher by 0.9 than in the section without cooling (P < 0.001). Due to low indoor air flow velocity (below 0.18 m/s), a change in apparent temperature by the Comprehensive Climate Index (CCI) was only 1.94°C. It would be possible to provide markedly better cooling effectiveness by increasing the air velocity up to 2 m/s, which may improve...
Design of active stability control system of agricultural off-road vehiclesOriginal Paper
J. Rédl, V. Váliková, J. Antl
Res. Agr. Eng., 2014, 60(10):S77-S84 | DOI: 10.17221/39/2013-RAE
Part of active stability control system design of an agricultural technological vehicle designated for working in mountain and foothill areas is described. The principle of active control of angular velocities of the centre of gravity has been used. During the manoeuvre, active tipping axes are identified by orientation of the weight vector. From experimental tests of a machine MT8-222 based on the Standard STN 47 0170, the real records of angular velocities were obtained. Tests were executed on the slope with an average slope of 32 degrees. From computation critical angular velocities were gained, by which the machine could get into the position of...
Machinability improvement using high-pressure cooling in turningOriginal Paper
R. Drlička, V. Kročko, M. Matúš
Res. Agr. Eng., 2014, 60(10):S70-S76 | DOI: 10.17221/38/2013-RAE
Process fluids are used primarily for their cooling and lubricating effect in machining. Many ways to improve their performance have been proposed; the analysis of some of them is provided in the paper. The effect of high pressure cooling has been investigated with regard to chip formation and tool life. Standard and for high pressure application particularly designed indexable cutting inserts were used with fluid pressure 1.5 and 7.5 MPa. The pressure effect on tool life at different feed rates was observed as well. Not each cooling pressure value or machined material showed favourable chip formation. Tool life though has improved significantly while...
Determination of mechanical properties of soil under laboratory conditionsOriginal Paper
V. Malý, M. Kučera
Res. Agr. Eng., 2014, 60(10):S66-S69 | DOI: 10.17221/37/2013-RAE
This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area...
Monitoring of conditions of agricultural machines' parts in operationOriginal Paper
P. Polák, R. Mikuš, V. Kročko
Res. Agr. Eng., 2014, 60(10):S57-S65 | DOI: 10.17221/36/2013-RAE
This contribution focuses on problems of monitoring the runout of tractor diesel motor parts used in agricultural operation. Crankshafts from the agricultural tractors of type Zetor 6911 are used as samples for measuring the runout and circularity. The first sample of the crankshaft is loaded in the tractor used in livestock production, and the second one is used in vegetable production. Measured values of the runout and circularity of both samples are evaluated by tables and polar diagrams. Results of the experiment show the amount of runout and the following wear of agricultural machine parts in different operating conditions of agricultural production.
Sorption isotherms of agricultural productsOriginal Paper
I. Vitázek, J. Havelka
Res. Agr. Eng., 2014, 60(10):S52-S56 | DOI: 10.17221/35/2013-RAE
The aim of the paper is to expand the theory of sorption and equilibrium moisture contents as well as to present the methodology of developing two types of sorption isotherms - I and II. The attention is also paid to the importance of the isotherms in the thermodynamics of drying and in the process of storage of agricultural products. Presented methodology of obtaining the isotherms is based on selected equations of the theory of adsorption and on the results of experimental measurements of equilibrium moisture content. Definition of the new isotherm II is introduced as dependence of equilibrium moisture content dry basis on time at constant temperature,...
Determining the management zones with hierarchic and non-hierarchic clustering methodsOriginal Paper
J. Galambošová, V. Rataj, R. Prokeinová, J. Prešinská
Res. Agr. Eng., 2014, 60(10):S44-S51 | DOI: 10.17221/34/2013-RAE
Delineation of the management zones of a field is commonly used in precision agriculture technology. There are many techniques used to identify management zones. The most used technique is k-means clustering, where the number of clusters is managed by the user. The paper deals with clustering the yield data and electromagnetic data of a 17 ha field using the Ward's method followed by the k-means clustering method. The cubic clustering criterion was used to determine the number of clusters. Based on results, it can be concluded that it is beneficial to combine the k-means clustering method with the hierarchic method (Ward's method).
Performance parameters monitoring of the hydraulic system with bio-oilOriginal Paper
I. Janoško, T. Polonec, S. Lindák
Res. Agr. Eng., 2014, 60(10):S37-S43 | DOI: 10.17221/32/2013-RAE
In environmental terms, hydraulic fluids used in the hydraulic system of municipal vehicles represent problems related to a potential leakage from the system into the environment and the subsequent contamination of groundwater and soil. More environment-friendly way is to use green hydraulic fluids that are biodegradable in accidents. This paper aims to investigate the possibilities of biodegradable oil application and its adaptation in the hydraulic systems of municipal vehicles by monitoring the impact of the bio-oil Mobil EAL 46 ESSO on the performance parameters as flow, efficiency, durability, etc. Hydraulic pump revolutions were measured using...
Fuzzy control of temperature and humidity microclimate in closed areas for poultry breedingOriginal Paper
M. Olejár, V. Cviklovič, D. Hrubý, L. Tóth
Res. Agr. Eng., 2014, 60(10):S31-S36 | DOI: 10.17221/30/2013-RAE
This contribution describes the ways of temperature and humidity microclimate control in breeding areas using a fuzzy controller. It is focused on poultry, whereby the most important parameters for optimal breeding are temperature and humidity. The main aim was to evaluate the control process according to control quality in the controller's steady state and the power consumption of the system. The used control algorithm was designed in the Matlab application, and it was practically verified in a closed thermodynamic system. Practical measurements have shown that with an increasing number of fuzzy controller's interference rules a better control quality...
Research of journal bearings for using in agricultural mobile machinesOriginal Paper
M. Kadnár, J. Rusnák, M. Bujna, J. Valíček, M. Kušnerová, P. Tököly
Res. Agr. Eng., 2014, 60(10):S25-S30 | DOI: 10.17221/29/2013-RAE
The competitive environment forces producers in agricultural machine industry to decrease the costs. Producers as well as sub-suppliers need to find possible savings. The paper presents results of laboratory experiments with real journal bearings made of bimetallic alloy performed to find out possible replacement of a rolling bearing by a journal bearing. An important correlation between the results of laboratory experiments with a model of tribological system and the real journal node can be achieved by a maximum approach of simulation features by real running conditions. Thus, the given experiment conditions result from the chosen application, i.e....
Assessment of risks in implementing automated satellite navigation systemsOriginal Paper
M. Žitňák, M. Macák, M. Korenko
Res. Agr. Eng., 2014, 60(10):S16-S24 | DOI: 10.17221/28/2013-RAE
One of the ways of increasing the efficiency and safety of work is the implementation of navigation systems in agricultural practice. Satellite navigation as a means of reducing the unit costs and increasing the safety can have a significant economic impact on a company when properly used. The objective of measurement was to assess the accuracy of a satellite system AutoTrack working with a correction signal SF2. Its provider specifies an accuracy of ± 5 cm for this signal type. The accuracy of machine work was compared for two scenarios, i.e. with and without satellite navigation. Further, the navigation of machines focused predominantly on...
Verification of the working life of a ploughshare renovated by surfacing and remelting in the operationOriginal Paper
I. Kováč, N. Vanko, M. Vysočanská
Res. Agr. Eng., 2014, 60(10):S98-S103 | DOI: 10.17221/59/2012-RAE
The most common way of renovation of the working parts of agricultural machinery is surfacing by hardfacing coated electrodes and piped hardfacing wires. Another way to prolong the working life of the machinery is the chemical heat treatment of the material surface by nitriding. By nitriding, high hardness is obtained of the surface affected by a suitable environment and by raised temperature. This paper deals with the possibilities of increasing the lifetime of the functional area of a ploughshare by the surfacing piped wire and hardfacing electrodes and reshaping the surface layer in an argon and nitrogen environment by using a welding rectifier...