Research in Agricultural Engineering, 2011 (vol. 57), issue 2
Heat-emission analysis of small combustion equipments for biomass
J. Malaťák, L. Passian
Res. Agr. Eng., 2011, 57(2):37-50 | DOI: 10.17221/28/2010-RAE 
The article addresses the urgent questions regarding the use of biomass as a fuel for combustion equipment of the heat output up to 25 kW. The article is based on the determined elemental analyses of six samples of fuel taken both from the wood mass and herbaceous biomass. These samples underwent the stoichiometric analysis of fuels. After the stoichiometric analysis the heat-emission characteristics were determined on two combustion equipments. The results of carried out elemental and stoichiometric analyses indicate higher values of nitrogen, sulphur and chlorine concentration in herbaceous biomass from agriculture compared to the analyzed wood mass....
Sensors connection for yield determination on round balers with variable chamber
M. Kroulík, J. Mašek, Z. Kvíz, B. Jošt, V. Prošek
Res. Agr. Eng., 2011, 57(2):51-55 | DOI: 10.17221/24/2010-RAE
The main aim of this article is to present a technical solution for straw and forage yield mapping when using round balers with variable chamber for harvest. The yield measurement is based on monitoring of instantaneous position of a tension roller mechanism for press chamber circular belt. Wheat straw was harvested - baled, during our trial measurements. The acreage of the trial field was 12 ha. Calibration of the measuring system showed a strong dependence of the tension roller position on the amount of pressed straw (R2 = 0.99). Geostatistical evaluation confirms a spatial relationship of measured data sets with a moderate spatial...
Effects of MIG process parameters on the geometry and dilution of the bead in the automatic surfacing
R. Chotěborský, M. Navrátilová, P. Hrabě
Res. Agr. Eng., 2011, 57(2):56-62 | DOI: 10.17221/19/2010-RAE
Automatic weld surfacing is being employed increasingly in the process, mining and power industries. Gas metal arc welding has become a natural choice for automatic surfacing due to its important properties. These include: high reliability, all positions capabilities, ease of use, low cost and high productivity. With increasing use of gas metal arc welding in its automatic mode, the use of mathematical models to predict the dimensions of the weld bead has become necessary. The development of such mathematical equations using a four factor central factorial technique to predict the geometry of the weld bead in the deposition of OK Tubrodur 15.43 electrode...
Technical-economical indicators in the sugar beet transportation management
M. Žitňák, M. Korenko
Res. Agr. Eng., 2011, 57(2):63-71 | DOI: 10.17221/29/2010-RAE
Work deals with the transportation and manipulation of sugar beet from storages to sugar refineries. The aim is evaluation of sugar beet transport organization and further transport suggestion and way of its organization in order to minimize transported material costs per unit. The aim attainment is reached by setting up mathematical model necessary for creating the lines for sugar beet transport and their comparison in term of unit costs is made. Result of this work is model of transportation process according to individual variants and object is vehicles efficiency determination, unit costs per ton of transported sugar beet, number of vehicles, number...
Behaviour of different moisture contents of Jatropha curcas L. seeds under compression loading
A. Kabutey, D. Herák, A. Sedláček
Res. Agr. Eng., 2011, 57(2):72-77 | DOI: 10.17221/15/2010-RAE
A study was conducted to investigate the behaviour of different moisture contents of Jatropha curcas L. seeds under compression loading. To obtain jatropha seeds of different moisture contents ranging from 1% (w.b.) to 37% (w.b.), the seeds were soaked in water and kept in a refrigerator at 5°C for different number of days. Compression devices, namely ZDM 50-2313/56/18, pressing vessel with diameter of 76 mm and a pressing plunger of 90 mm height, were used. The amount of seeds in the pressing vessel was measured as 40 mm with compression force of 98,100 N. The results from the experiment showed that increasing the moisture content of the...