Research in Agricultural Engineering, 2007 (vol. 53), issue 4
Milking-related changes of teat temperature caused by various milking machines
J. Vegricht, A. Machálek, P. Ambrož, U. Brehme, S. Rose
Res. Agr. Eng., 2007, 53(4):121-125 | DOI: 10.17221/1954-RAE 
The aim of the performed work was to verify the hypothesis that different milking equipments have different influence on the blood circulation in the milk gland during milking. This influence was investigated by measuring the surface temperature of the milk gland using thermography. The influence was monitored of 5 different milking units in total, out of them 2 AMS, on the teat temperature which was scanned and evaluated in the teat tip centre and on the teat base at the same time with the surface temperature of the udder, always at the instant closely preceding the cluster application and then after its removal. It was ascertained that the average...
Research of the utilization of biotechnological agents for the reduction of ammonia and greenhouse gases emissions in livestock breeding in the Czech Republic
A. Jelínek, M. Dědina, R. Kraus
Res. Agr. Eng., 2007, 53(4):126-133 | DOI: 10.17221/1960-RAE
The reduction of ammonia and greenhouse gases emissions resulting from the livestock breeding is conditioned by the performance of many experiments for the reducing technologies verification. The utilisation of biotechnological agents in the livestock breeding enables to reduce not only ammonia but in many cases also the principal greenhouse gases. In the paper is presented the system and methodology of the measurements, the choice of more than eighty authorised measurements, and the determination of the emission factors for methane, carbon dioxide, hydrogen sulphide, and nitrogen oxide from pig and poultry breeding.
Monitoring of burden gases emission levels after farmyard manure application in grapevine and vegetable growing
M. Češpiva, P. Burg
Res. Agr. Eng., 2007, 53(4):134-142 | DOI: 10.17221/1953-RAE
Ammonia and greenhouse gas emissions released during the application of farmyard manure in the crop production belong to the most significant air pollution resources of the agricultural activity. In this paper, the results are described of the emissions measurements in different ways of farmyard manure application in grapevine and vegetable growing. On the basis of the emissions measured, optimum procedures of the farmyard manure application were suggested with regard to the burden of environment by the monitored gases as low as possible. Also presented are the system and methodology of measuring the burden gases coming from soil by means of measuring...
Equipment for the determination of dielectric properties of vegetable tissue during its mechanical loading
J. Sobotka, J. Krejčí, J. Blahovec
Res. Agr. Eng., 2007, 53(4):143-148 | DOI: 10.17221/1955-RAE
The internal structures of agricultural products change substantially in the course of the products deformation. One of the main changes in this process is the loss of the water content and water solutions generally due to the squeezing out of the cellular sap. The water content can be detected also by electric conductivity measured at different frequencies. The precise measurement of the electric conductivity during the deformation of soft agricultural products can be used as a simple indicative method for the study of the processes that control the squeezing out of the cellular sap including the filtration abilities of the cellular walls. In the...
Dynamic laboratory measurement with dielectric sensor for forage mass flow determination
F. Kumhála, Z. Kvíz, J. Kmoch, V. Prošek
Res. Agr. Eng., 2007, 53(4):149-154 | DOI: 10.17221/1959-RAE
A new parallel plate capacitance sensor was built consisting of two metal sheets. The sensor - a capacitor and the whole oscillating circuit was driven at 27 MHz frequency. Dynamic laboratory experiments were performed with grass from a natural meadow in order to evaluate the possibility of the forage mass flow determination by means of this sensor. The results revealed a relatively strong linear relationship between the feed rates of the wet forage crop material passing through the sensor between its plates and the measured capacitance sensor circuit output frequency. The coefficients of determination (R2) varied from 0.9 to 0.96. Further...
Drying of hop
J. Mejzr, B. Hanousek
Res. Agr. Eng., 2007, 53(4):155-160 | DOI: 10.17221/1957-RAE
In the Czech Republic, belt kilns are predominantly used for hop drying. As in the world other types of hop kilns, such as box kilns, are also frequently used, the comparison appears desirable between the efficiency and quality of the technological processes in the individual kiln types. The present work is aimed at determining the hop drying parameters in the belt hop kiln, and their optimisation.
Parametres of energy crop biomass handling
J. Souček, V. Kocánová, M. Novák
Res. Agr. Eng., 2007, 53(4):161-165 | DOI: 10.17221/1952-RAE
Energy crop handling can be performed with standard handling machinery equipped with suitable adaptors. The authors describe and compare various types of handling of wood and herb energy crops. The published results have been gained by field measurements in operating conditions and calculated on the basis of bulk weight. Particular handling variants are supplemented with rough values of unit costs obtained by model calculation.
Selection procedure and multicriterial selection of small and bigger lorries
V. Drobný, M. Kavka, V. Tlustý
Res. Agr. Eng., 2007, 53(4):166-171 | DOI: 10.17221/1962-RAE
The developed car market makes demands on the potential user in the Czech Republic in view of the selection, purchase and operation. More vehicles appear on the market and it is far more complicated to make a good choice. There are plenty of methods and ways to simplify or improve the selection procedure. The article presented solves a multicriterial selection issue based on the results of a survey of small and bigger lorries. The main method of multi-criteria selection was PATTERN (Planning Assistance Trough Technical Evaluation of Relevant Numbers) suitable for the comparison of non-homogeneous criteria targeting a row of significance of each variant.
Investigating the pumping process of a resonance-vibrating pump for medium-depth boreholes
I.A. Loukanov
Res. Agr. Eng., 2007, 53(4):172-181 | DOI: 10.17221/1956-RAE
This paper deals with the pumping process of a resonance-vibrating pump, which utilizes the resonance vibrations of one degree-of-freedom oscillating system. The pump is powered by a mechanical shaker consisting of two counter rotating offset masses and operating in resonance. The study investigates the nature of the pumping process and conditions required to achieve pumping action. Equations for the flow rate, pressure developed at ground level or any height above it, the pump efficiency, and the power delivered by the shaker are derived. The analysis of the pumping process revealed that the flow rate of the pump may be maximized either by increasing...
The model of oscillating system with coil and its validation
P. Kočárník, S. Jirků
Res. Agr. Eng., 2007, 53(4):182-187 | DOI: 10.17221/1958-RAE
This article demonstrates the solution of a dynamic system with a complex kinematical structure and rolling resistance in the Matlab-Simulink program. To validate the simulation, a physical model with an incremental sensor was established which allows us to measure the kinematical values while the system is in motion. The article also includes the simulation model block diagram and the calculated course of kinematical values. Numeric results were compared with the real model. The measurement proved good conformity in basic parameters such as the period time, amplitude decrease, stop time etc. Small deviations in the final phase may have been caused...
INDEX (VOLUME 53)
editors
Res. Agr. Eng., 2007, 53(4):188-190 | DOI: 10.17221/1961-RAE