Research in Agricultural Engineering, 2018 (vol. 64), issue 2
Flow rate of liquid cattle manure leakage into subsoil during storageOriginal Paper
Jiří Vegricht, Josef Šimon, David Hájek, Jiří Bradna
Res. Agr. Eng., 2018, 64(2):49-54 | DOI: 10.17221/109/2017-RAE 
Under laboratory conditions, seepage of liquid cattle manure with dry matter content of 3-8% through subsoil was studied in relation to its dry matter content and period of storage. Statistical dependence of the total amount of eluate on the dry matter has been found (P = 0.0013). A hypothesis was also confirmed that liquid cattle manure shows a sealing effect during storage. It was found that the average value of coefficient of permeability decreases as soon as 48 hours after the start of storage under the value 5.56171 × 10-6 cm.
Evaluation of the coefficient of uniformity and non-uniformity of irrigation for wide-range irrigators in various field conditionsOriginal Paper
Ján Jobbágy, Koloman Krištof
Res. Agr. Eng., 2018, 64(2):55-62 | DOI: 10.17221/8/2017-RAE
The aim of this paper is to address an issue of work quality of irrigation machines with eight parameters that were selected and defined as input variables. The objective of the study was to determine possibilities of different evaluation methods for a wide range of irrigation machines and their versatility. All input conditions that could affect the results were recorded and analysed. The results were statistically analysed by a linear model (ANOVA). The results confirm that there are no statistically significant differences in used evaluation methods (p > 0.05) when the effect of locality was not considered. When the effect of locality...
Functional properties of blade tiller working toolsOriginal Paper
Radek Pražan, Josef Hůla, Pavel Kovaříček, Jakub Čedík, Ilona Gerndtová, Marcela Vlášková
Res. Agr. Eng., 2018, 64(2):63-69 | DOI: 10.17221/106/2017-RAE
After the harvest of winter wheat, the tensile force, cross section of loosened soil and specific resistance of soil were measured on a loamy soil plot. During the comparative measurements, 3 blades were used with chisel width of 20 mm, 40 mm and 75 mm. In case of all blades, the measurements were carried out at the depth of 100, 200 and 300 mm. In the course of measurements, the standards of blades were attached in a measuring frame on six-component hinge with connected tensometric sensor. The selected blades were developed for a new type of tiller destined for primary cultivation of soil. Moreover, in case of a blade equipped by chisel there were...
Indicators of а fruit detacher with non-symmetric angular oscillations at removing tomato fruitsOriginal Paper
Stoyan Ishpekov, Petar Petrov, Rangel Zaykov, Nayden Naydenov
Res. Agr. Eng., 2018, 64(2):70-76 | DOI: 10.17221/51/2017-RAE
The main qualitative and quantitative indicators of a newly developed fruit detacher with non-symmetric angular oscillations have been investigated at inertial removal of fruits of table tomato varieties from stems. The detacher removes over 95% of the fruits of examined tomato varieties 'Tomsk' and 'Tobray', without damaging them mechanically at frequency of oscillations from 10.8 to 13.3 Hz and initial elastic moment of the clutch from 0 to 2.0 Nm. The detacher achieves the productivity for plants from 1.554 to 11.650 kg.s-1 and the productivity for fruits of 0.827 to 6.921 kg.s
Mechanical test suitable for detection of bug-damage wheat grains abstractOriginal Paper
Zahra Basati, Mansour Rasekh, Yousef Abbaspour-Gilandeh
Res. Agr. Eng., 2018, 64(2):77-84 | DOI: 10.17221/45/2017-RAE
Considering the fact that the presence of bug-damaged wheat in the bulk results in a decrease of the flour quality and its final product, which is bread, it is necessary to differentiate the bug-damaged wheat grains from the healthy ones. Therefore, the present study investigated the mechanical properties of bug-damaged and healthy wheat grains of the Azar cultivar. By making use of these mechanical properties, it would be possible to provide a more precise texture identification of the bug-damaged wheat grains compared to the healthy ones. In this study, the mechanical properties (rupture energy, toughness and apparent elastic coefficient) were determined...
Engine performance and exhaust emission characteristics of paraffinic diesel fuel in a model diesel engineOriginal Paper
Petr Jevič, Radek Pražan, Zdeňka Šedivá
Res. Agr. Eng., 2018, 64(2):85-95 | DOI: 10.17221/113/2017-RAE
The article deals with verification of a diesel fuel and two fuel mixtures blends with different amounts of the bio-component using the model single-cylinder engine without the additional equipment for treatment of exhaust gases. This combustion diesel engine served for measuring the performance characteristics of the model single-cylinder engine and the individual emission components in order to assess the use of these blends of liquid paraffinic diesel fuel in practice and to meet current and forthcoming European legislation and to fulfil the commitments by 2020. A detailed chemical analysis was performed in case of all the tested paraffinic diesel fuels.
Changes in nutritional and energy properties of soybean seed and hull after roastingOriginal Paper
Tajana Krička, Ana Matin, Neven Voća, Ana Pospišil, Mateja Grubor, Ivana Šaronja, Vanja Jurišić
Res. Agr. Eng., 2018, 64(2):96-103 | DOI: 10.17221/29/2016-RAE
After harvesting, soybean seed must be thermally treated because of the increased moisture content. The most common thermal treatment of soybean is roasting, with three indicators that are critical for the process itself: seed moisture content, roasting period and process temperature. Following the above-mentioned, the aim of this paper was to determine nutritional and energy changes in three soybean varieties ('Gordana', 'Sivka' and 'Slavonka'). After collecting the samples, the nutrient structure of the core and energy components of seed hull for each variety were determined before and after the heat treatment by roasting. The roasted soybean seeds...
Application of eggshell wastes as valuable and utilizable products: A reviewReview
Hamideh Faridi, Akbar Arabhosseini
Res. Agr. Eng., 2018, 64(2):104-114 | DOI: 10.17221/6/2017-RAE
Eggshell is a solid waste, with production of several tons per day. Eggshell is mostly sent to the landfill with a high management cost. It is economical to transform the eggshell waste to create new values from these waste materials. The present article is an attempt to summarize the possible applications of eggshell. The eggshell waste can be used (a) at biodiesel production as a solid base catalyst used for biodiesel pollutants minimization, reducing the production costs of biodiesel and making the process of biodiesel production fully ecological and environment-friendly; (b) as an absorbent of heavy metals from wastewater as it is a serious environmental...