Research in Agricultural Engineering, 2010 (vol. 56), issue 3
Study of knotweed (Reynoutria) as possible phytomass resource for energy and industrial utilization
Z. Strašil, J. Kára
Res. Agr. Eng., 2010, 56(3):85-91 | DOI: 10.17221/46/2009-RAE 
This paper deals with the Reynoutria × bohemica and Reynoutria japonica under conditions of the Czech Republic. It evaluates the impact of soil, weather conditions and various terms of harvest (autumn, spring) on the yield, dry matter content, phytomass loss, ash content, and basic elements content change in plants. Heavy metals content was determined in soil where plants were grown and consequently in plants themselves. The average yield of dry matter at the fully closed stands of Reynoutria japonica were 9.06 t/ha in autumn, Reynoutria × bohemica from 13.23 to 21.41 t/ha, according to the site. The yield losses within the winter period were found...
Light and noise conditions of buildings for breeding dairy cows
M. Šístková, A. Peterka, B. Peterka
Res. Agr. Eng., 2010, 56(3):92-98 | DOI: 10.17221/43/2009-RAE
Check measurement of the illuminance, the uniformity ratio of illuminance and noise level was made in the selected stable building to prove quality of lightning both for service workers and the cattle. The measurement discovered that the noise level, the day lighting and artificial lighting do not satisfy valid health standards and can have harmful effect upon human and cattle organism. In the monitored stable building the permissible hygienic limit of noise was exceeded only during distribution of feed and bedding and it only for the short time.
Study on some engineering attributes of pine nut (Pinus pinea) to the design of processing equipment
S.M.T. Gharibzahedi, V. Etemad, J. Mirarab-Razi, M. Fos'hat
Res. Agr. Eng., 2010, 56(3):99-106 | DOI: 10.17221/49/2009-RAE
Moisture-dependent engineering properties of pine nut were studied at 6.3, 8.2, 10.8, 14.5, 18.9, and 20.1% moisture content (dry basis). The length, width, thickness, and geometric mean diameter increased significantly (P < 0.05) from 21.75 to 21.85 mm, 7.39 to 7.47 mm, 6.07 to 6.14 mm, and 9.89 to 9.98 mm, respectively, with an increase in moisture content from 6.3% to 20.1%, whereas the increase in sphericity from 45.49% to 45.69% was not significant. Similarly, thousand seed mass, true density, porosity, terminal velocity, and angle of repose increased (P < 0.05) from 0.85 to 0.93 kg, 1043.3 to 1071 kg/m3, 41.31% to 44.57%,...
Influence of top link length of three-point hitch on performance parameters of ploughing set
J. Čupera, T. Šmerda
Res. Agr. Eng., 2010, 56(3):107-115 | DOI: 10.17221/32/2009-RAE
The target of the realized measurement was to subject the influence of top link on wheel slip and performance and economic parameters of ploughing set. To meet the objectives the set of New Holland 7050 tractor aggregated with plough Kuhn Variomaster 150 was used during field work. Parameters of internal systems were monitored via CAN-Bus, e.g. engine speed, fuel consumption, fuel temperature, atmospheric pressure, intake air temperature, time of trip, etc. Additional external measurement consisted of a signal of rear wheels rotation and signal of radar sensor for slip determination. Load cell sensor HBM was mounted into a top link. The values of slip...
The durability test of tractor hydrostatic pump type UD 25 under operating load
Š. Drabant, J. Kosiba, J. Jablonický, J. Tulík
Res. Agr. Eng., 2010, 56(3):116-121 | DOI: 10.17221/42/2009-RAE
The results of the UD 25 hydrostatic pump durability test are presented; they were obtained in the laboratory under operating load. The test of operating load was a continuation of the hydrostatic pump durability test with a cyclic pressure loading according to the norm STN 11 9287. It lasted 300 hours, with 70°C ± 2°C of hydraulic fluid temperature. The aim of the test was to simulate the operation of the hydrostatic pump under load in laboratory and to find out its deterioration and the influence of a biodegradable fluid on its qualities. The achieved results confirmed that flow efficiency of the UD 25 hydrostatic pump decreased only to 3.6%...
Lipase-catalyzed transesterification of rendering plant fat - Short Communication
A. Prošková, Z. Kopicová, J. Kučera, L. Škarková
Res. Agr. Eng., 2010, 56(3):122-125 | DOI: 10.17221/40/2009-RAE
Soluble lipase (Lipozyme CALB L) was immobilized by covalent bond to chitosan pellets prepared from Aspergillus niger mycelium. This immobilized enzyme was compared with commercial immobilized lipase of the same origin (Novozym 435). Novozym 435 is also lipase CALB L commercially immobilized by sorption on poly-(methyl acrylate). Novozym 435 shows much higher conversion of rendering plant fat in methanol under optimum conditions, having, at the same time, lower optimum temperature and lower stability at higher temperature. Lipozyme CALB L immobilized on chitosan leads to a low conversion, regardless its higher thermal stability. Novozym 435...