Template-Type: ReDIF-Article 1.0
Author-Name: J. Blahovec
Author-Workplace-Name: Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: A. Hejlová
Author-Workplace-Name: Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: J. Vacek
Author-Workplace-Name: Potato Research Institute, Havlíčkův Brod, Czech Republic
Title: Impact induced mechanical damage of Agria potato tubers cultivated in different regimes
Abstract: The Agria potato tubers were grown in 2005 in cultivation regimes involving different irrigation and fertilisation levels and forms. The impact induced tuber damage was simulated dynamically by an impact pendulum test and studied with the aim to detect some relationship between the cultivation regimes and the type and extent of the damage. The usual bruising presented as black spots is in many cases masked by other mechanisms of damage, e.g. by tuber cracking and/or crushing. The highest degree of tuber cracking and at the same time the least frequent bruising were observed for tubers cultivated in the regime with irrigation and without fertilising. The bruising was more pronounced in the narrower tuber side in comparison to the wider flat side in all cultivation regimes. Some results could be compared with similar previous measurements performed on tubers from the same field experiment organised during three successive years 2003-2005. The flatter side parts of the Agria tubers are more sensitive to bruising than the more oblique ones. The bruise spot shape depends mainly on its dimension. The role of different cultivation regimes can be interpreted in this way.
Keywords: potato, density, stem, bud, cultivation regime, impact, bruising, cracking, crushing, irrigation, fertilisation
Journal: Research in Agricultural Engineering
Pages: 81-86
Volume: 52
Issue: 3
Year: 2006
DOI: 10.17221/4883-RAE
File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4883-RAE.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200603-0001.txt
Handle: RePEc:caa:jnlrae:v:52:y:2006:i:3:id:4883-RAE

Template-Type: ReDIF-Article 1.0
Author-Name: V. Bulgakov
Author-Workplace-Name: Educational and Research Technical Institute, National Agrarian University of Ukraine, Kyiv, Ukraine
Author-Name: I. Holovach
Author-Workplace-Name: Educational and Research Technical Institute, National Agrarian University of Ukraine, Kyiv, Ukraine
Author-Name: M. Berezovyy
Author-Workplace-Name: Educational and Research Technical Institute, National Agrarian University of Ukraine, Kyiv, Ukraine
Title: The plane interaction theory of the cleaning vane with the head of a root crop
Abstract: New interaction theory of a flexible cleaning vane with the head surface of root crop in the case when the vane installed on the driving shaft makes a plane motion is proposed. Based on the obtained differential equations of the vane motion some new mathematical dependencies, describing the basic parameters of this interaction are given.
Keywords: flexible cleaning vane, head of root crop, plane motion, differential equation, interaction
Journal: Research in Agricultural Engineering
Pages: 87-96
Volume: 52
Issue: 3
Year: 2006
DOI: 10.17221/4884-RAE
File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4884-RAE.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200603-0002.txt
Handle: RePEc:caa:jnlrae:v:52:y:2006:i:3:id:4884-RAE

Template-Type: ReDIF-Article 1.0
Author-Name: M. Loučka
Author-Workplace-Name: Department of Mathematics, Faculty of Chemical Engineering, Institute of Chemical Technology, Prague, Czech Republic
Author-Name: P. Veselý
Author-Workplace-Name: Department of Mathematics, Faculty of Chemical Engineering, Institute of Chemical Technology, Prague, Czech Republic
Author-Name: F. Jaroš
Author-Workplace-Name: Department of Mathematics, Faculty of Chemical Engineering, Institute of Chemical Technology, Prague, Czech Republic
Author-Name: J. Pavlík
Author-Workplace-Name: Department of Mathematics, Faculty of Chemical Engineering, Institute of Chemical Technology, Prague, Czech Republic
Title: One-parameter model of sterilisation process. Heating and cooling period
Abstract: The article deals with the simplification of the heat transfer model for food sterilisation in cans and jars. The one-parameter model was derived and identification procedures of its parameters were examined. It is shown that the concept of the first order dynamics satisfies the technological purposes but the common method of the least squares is not suitable for the calculation of model constants. A new computing method is presented and compared with statistically evaluated experiments with wide range of stuffs and packages.
Keywords: sterilisation effect, thermal treating of foods, temperature profile, parameters evaluation, first order dynamics, preservation of foods, thermal processing
Journal: Research in Agricultural Engineering
Pages: 97-106
Volume: 52
Issue: 3
Year: 2006
DOI: 10.17221/4885-RAE
File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4885-RAE.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200603-0003.txt
Handle: RePEc:caa:jnlrae:v:52:y:2006:i:3:id:4885-RAE

Template-Type: ReDIF-Article 1.0
Author-Name: D. Herák
Author-Workplace-Name: Department of Mechanics and Engineering, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: R. Chotěborský
Author-Workplace-Name: Department of Material and Engineering Technologies, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: A. Sedláček
Author-Workplace-Name: Department of Mechanics and Engineering, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: E. Janča
Author-Workplace-Name: Department of Mechanics and Engineering, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Title: Exploitation of Hertz's contact pressures in friction drives
Abstract: The paper is intent on the applications of equations which describe the Hertz's surface pressures in friction drives. In the paper the reduced equations are derived, which are useful to the surface pressures calculation in friction drives when ball - ball, cylinder - cylinder, cone - cone are kept in touch and their graphical representation of stress distribution in the contact area is presented. Using the Hertz's surface pressures and the Mohr's circles the substance of pitting start is derived and the stress distributions using the elementary joists, which were situated on the axe z in the section under the contact joist, are represented.
Keywords: contact pressures, friction drive, Hertz's pressures, pitting, friction force, Mohr's circles
Journal: Research in Agricultural Engineering
Pages: 107-113
Volume: 52
Issue: 3
Year: 2006
DOI: 10.17221/4886-RAE
File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4886-RAE.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200603-0004.txt
Handle: RePEc:caa:jnlrae:v:52:y:2006:i:3:id:4886-RAE

Template-Type: ReDIF-Article 1.0
Author-Name: P. Hrabě
Author-Workplace-Name: Department of Material and Engineering Technologies, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: R. Chotěborský
Author-Workplace-Name: Department of Material and Engineering Technologies, Technical Faculty, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: R. Medlín
Author-Workplace-Name: New Technologies - Research Centre in Westbohemian Region, Pilsen, Czech Republic
Title: Influence of overlay layers on the abrasive wear
Abstract: A problem of machine parts wear decrease and in this way of the economical effectiveness of rapid wearable parts interferes with majority of manufacturing processes. Service life and operating reliability of a great number of machine parts is largely influenced by friction and wear, which take a significant part in the power and material losses. Wear affects significantly the maintenance, repair and renewal costs of machine parts, too. Today we can use a row of overlay materials. They differ above all by chemical composition, which determinates the conditions of use. Next conditions are the solidification of the welded-on material and the diffusion ability of main alloying elements, which determine the resultant structure of an overlay. The paper intents on multilayer overlays problem and on the number of overlay layers influence on abrasive wear.
Keywords: abrasive wear, abrasive particle, overlay materials, functional surfaces, abrasive cloth
Journal: Research in Agricultural Engineering
Pages: 115-122
Volume: 52
Issue: 3
Year: 2006
DOI: 10.17221/4887-RAE
File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4887-RAE.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200603-0005.txt
Handle: RePEc:caa:jnlrae:v:52:y:2006:i:3:id:4887-RAE