Template-Type: ReDIF-Article 1.0 Author-Name: J. Malaťák Author-Workplace-Name: Department of Technological Equipment of Buildings, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: L. Passian Author-Workplace-Name: Department of Technological Equipment of Buildings, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Heat-emission analysis of small combustion equipments for biomass Abstract: 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. The selection of combustion equipment is particularly influenced by increased contents of sulphur and chlorine (corrosive behaviour). The net calorific value of the analyzed samples taken from the wood mass is higher than of samples taken from the herbaceous biomass. The net calorific value of fuels from herbaceous biomass is reduced due to a higher content of ashes in the fuel. The results of thermal-emission analyses show higher values of nitrogen oxides, sulphur and chlorine concentrations in the herbaceous biomass compared to the analyzed wood mass. The emission concentrations of carbon monoxide for wood fuels and herbaceous biomass also depend on the type of combustion equipment and setting of combustion air volume. The increased emissions of hydrogen chloride generated by various combustion equipments are primarily caused by the volume of combustion air and the amount of chlorine in the fuel itself. The higher the volume of combustion air brought into the combustion chamber is, the higher the emissions of hydrogen chloride are. Based on the analyses we can also draw a conclusion that the spaces of combustion equipment during combustion should be most burdened with the herbaceous biomass. Keywords: biomass, chemical analysis, stoichiometric analysis, net calorific value, emission Journal: Research in Agricultural Engineering Pages: 37-50 Volume: 57 Issue: 2 Year: 2011 DOI: 10.17221/28/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/28/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201102-0001.txt Handle: RePEc:caa:jnlrae:v:57:y:2011:i:2:id:28-2010-RAE Template-Type: ReDIF-Article 1.0 Author-Name: M. Kroulík Author-Workplace-Name: Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: J. Mašek Author-Workplace-Name: Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Z. Kvíz Author-Workplace-Name: Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: B. Jošt Author-Workplace-Name: Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: V. Prošek Author-Workplace-Name: Department of Machinery Utilisation, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Sensors connection for yield determination on round balers with variable chamber Abstract: 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 dependence. Finally, yield map of straw was created Keywords: forage crops, straw, throughtput, yield, yield mapping, round baler Journal: Research in Agricultural Engineering Pages: 51-55 Volume: 57 Issue: 2 Year: 2011 DOI: 10.17221/24/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/24/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201102-0002.txt Handle: RePEc:caa:jnlrae:v:57:y:2011:i:2:id:24-2010-RAE Template-Type: ReDIF-Article 1.0 Author-Name: R. Chotěborský Author-Workplace-Name: Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: M. Navrátilová Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: P. Hrabě Author-Workplace-Name: Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Effects of MIG process parameters on the geometry and dilution of the bead in the automatic surfacing Abstract: 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 onto structural steel S235JR is discussed. The models developed have been checked for their adequacy and significance by using the F test and the Student's t test, respectively Keywords: gas metal arc welding, weld bead, dilution, response surface methodology Journal: Research in Agricultural Engineering Pages: 56-62 Volume: 57 Issue: 2 Year: 2011 DOI: 10.17221/19/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/19/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201102-0003.txt Handle: RePEc:caa:jnlrae:v:57:y:2011:i:2:id:19-2010-RAE Template-Type: ReDIF-Article 1.0 Author-Name: M. Žitňák Author-Workplace-Name: Faculty of Engineering, Slovak University of Agriculture, Nitra, Slovak Republic Author-Name: M. Korenko Author-Workplace-Name: Faculty of Engineering, Slovak University of Agriculture, Nitra, Slovak Republic Title: Technical-economical indicators in the sugar beet transportation management Abstract: 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 of cleaning loaders providing the adjustment of sugar beet transportation to sugar refinery absorptive capacity and the traffic situation in sub-region of the relevant sugar refinery. Keywords: transportation, manipulation of the sugar, sugar beet transport, mathematical model Journal: Research in Agricultural Engineering Pages: 63-71 Volume: 57 Issue: 2 Year: 2011 DOI: 10.17221/29/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/29/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201102-0004.txt Handle: RePEc:caa:jnlrae:v:57:y:2011:i:2:id:29-2010-RAE Template-Type: ReDIF-Article 1.0 Author-Name: A. Kabutey Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: D. Herák Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: A. Sedláček Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Behaviour of different moisture contents of Jatropha curcas L. seeds under compression loading Abstract: 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 jatropha seeds influenced the force-deformation characteristic curve, deformation energy, maximum deformation and energy per unit volume. While moisture contents 1% (w.b.) and 10% (w.b.) displayed normal force-deformation characteristic, moisture contents 32% (w.b.) and 37% (w.b.) showed wave-effect characteristic. The R2 coefficient of determination value of 0.87 obtained from the effect of moisture content on deformation energy and unit volume energy shows that jatropha seeds of moisture content 16% (w.b.) would require minimum energy but high efficiency during compression. Keywords: jatropha seeds, moisture content, compressive force, deformation, wave-effect characteristic Journal: Research in Agricultural Engineering Pages: 72-77 Volume: 57 Issue: 2 Year: 2011 DOI: 10.17221/15/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/15/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201102-0005.txt Handle: RePEc:caa:jnlrae:v:57:y:2011:i:2:id:15-2010-RAE