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  • Author: Ján Kukla x
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Abstract

Kuklova M., Kukla J.: Transfer of risk elements in soil-bilberry system. Ekologia (Bratislava), Vol. 32, No. 2, p. 211-219, 2013.

Transfer of Al, Cr and Ni in the soil-plant (Vaccinium myrtillus L.) system was examined in four forest ecosystems in the localities Muraň (skeli-humic podzols) and Hliniky (dystric cambisols) in the protected zone of the NP Slovensky raj. In case of Al, the transfer coefficients were low, exceeding 1 only in the litter horizon on the damaged plot in the locality Muraň. The Al content in soils was the highest at a depth of 60-70 cm (10 249 mg kg-1) on the undamaged plot in Hliniky. The amounts of Al accumulated in bilberries were higher than the background value in plants, and they made 11-22% of the maximum Al contents detected in Ooh horizons of the studied soils. Cr on the damaged plot in the locality Muraň displayed higher transfer coefficients (range 1.09-11.3) in comparison with the other plots (0.03-0.59). Considering the value representing the maximum Cr amount detected in Ooh horizon in the corresponding locality as 100%, the content of Cr in bilberries growing on the damaged plot in Muraň was 109%, in contrast to 2% on the damaged plot in Hliniky. The concentrations of Ni in soils exceeded limit values in the surface humus horizons on all studied plots. Ni displayed higher transfer coefficients, exceeding 1 only on the damaged plot in the locality Muraň. Bilberries had accumulated 6-28% Ni in the locality Muraň, and 2-6% in the locality Hliniky of the maximum amounts detected in Ooh horizons of soils. The differences in mean values of transfer coefficients for Al, Ni and Cr were statistically significant (p < 0.05).

Abstract

The paper presents the results of a 23-year study of sulphate sulphur dynamics in beech ecosystems exposed to different immission loads. The amounts of S-SO4 2− in precipitation water entering the ecosystems were: the Kremnické vrchy Mts, a clear-cut area 519 kg ha−1 (24.7 kg ha−1 per year), a beech forest 476 kg ha−1 (22.7 kg ha−1 per year); the Štiavnické vrchy Mts an open place 401 kg ha−1 (24.6 kg ha−1 per year), a beech forest 324 kg ha−1 (19.1 kg ha−1 per year). The average SO4 2− concentrations in lysimetric solutions penetrating through surface humus to a depth of Cambisol 10 and 25 cm were increased as follows: in the Kremnické vrchy Mts from 12.71 to 16.17 mg l−1 and in the Štiavnické vrchy Mts from 18.73 to 28.80 mg l−1. The S-SO4 −2 amounts penetrating the individual soil layers in the Kremnické vrchy Mts were as follows: in case of surface humus on clear-cut area 459 kg ha−1 (20.9 kg ha−1 per year), in beech forest 433 kg ha−1 (19.7 kg ha−1 per year); below 10 cm organo-mineral layer of the mentioned plots penetrated 169–171 kg ha−1 (7.7–7.8 kg ha−1 per year), and below 25 cm mineral layer 155–255 kg ha−1 (7.1−11.6 kg ha−1 per year) – a higher amount was found on clear-cut area with an episodic lateral flow of soil solutions. In beech forest of the Štiavnické vrchy Mts penetrated below surface humus 424 kg ha−1 S-SO4 2− (18.9 kg ha−1 per year), below 10 cm mineral layer 458 kg ha−1 S-SO4 2− (19.9 kg ha−1 per year), and below 25 cm mineral layer as much as 599 kg ha−1 S-SO4 2− (26.0 kg ha−1 per year). This fact was caused by frequent lateral flow of soil solutions. The results indicate that the assumption about lower immission load of the beech ecosystem in the Kremnické vrchy Mts is wrong, at least in the case of S-SO4 2−. The testing has revealed that the studied beech ecosystems differ very significantly in sulphur amounts penetrating under 0.10 m and 0.25 m. The inter-annual differences were insignificant.

Abstract

The aim of the paper was to compare the litterfall and surface humus (Oo) quality in nudal beech stands with different emission-immission load from the Al smelter Žiar nad Hronom. The study was carried out in the Kremnické vrchy Mts (control stand, 18 km from the emission source) and the Štiavnické vrchy Mts (stressed stand, 1.5 km from the emission source), both in Central Slovakia. The contents of arsenic and nutrients (Cat, Mgt, Kt, Nat), with exception of calcium in the beech litterfall from the stressed stand were markedly higher (by 4.3%, 23.9%, 2.1% and 87.9%, respectively) compared to the samples taken from the control plot. On the contrary, the surface humus samples (with the exception of Na in the necrotic Oon subhorizon) from control plot were richer in nutrients. However, significant differences (p < 0.01) between the plots were observed for Ca content in the litterfall as well as in the surface humus. The concentrations of As in Oo samples from the stressed stand mainly increased with the organic horizon depth (mg kg-1): necrotic Oon 1.10 < fermentation Oof 3.1 < humification Ooh 55.6. The results showed, that As amounts detected in subhorizon Ooh and in beech litterfall from the stressed stand were higher than the limit values, thus indicating that the environment of the Žiar territory is exposed to persistent negative impacts of industrial activities.

Abstract

In this work, the calorific value content in the dry matter of the Scots pine (Pinus sylvestris L.) trees was evaluated. This dry matter was obtained only from the above-ground fractions of its biomass. Our experimental material was taken from five Scots pine trees situated in Slovakia. Wood and bark samples were obtained from the discs which were cut off from three locations, namely from the stem, branches of tree crowns and needles. Then, calorific value capacity (J g−1) in the dry matter of each sample was determined. The impact of statistically significant factors on the calorific value capacity was determined by means of analysis of variance. The average values are, according to the fractions, approximately in the range of 20,000–22,200 J g−1. The smallest capacity of the calorific value, approximately 20,000 J g−1, has the dry matter from bark obtained from the middle and crown parts of the stem. Then, the dry matter from stem wood and branches follows with a value of approximately 20,700 J g−1. Then follows dry matter of the coarse bark occurring on the stem butt and twigs that are covered with needles with a value of about 21,900 J g−1; and finally pine needles with the highest values of about 22,200 J g−1. The calorific value variability is relatively low with coefficients of variations of 0.9–2.8%.

Abstract

Vacuum fluctuation was measured using three different vacuum control methods. Firstly, the use was made of a control valve delivered by the manufacturer; then, an additionally installed frequency converter was used. Lastly, a frequency converter fitted with the stabilisation device prototype was used. First, control sensitivity according to ISO was measured in all the three alternatives. Then, vacuum fluctuation during milking was measured. To conduct the measurements under objectively identified conditions, another measurement was conducted with air feed during milking being replaced with a precisely defined variable flow rate. The conducted measurement confirmed the fact that when the frequency converter is used, vacuum fluctuation in stabilised condition is at the same level as when the control valve is used. If there are sudden changes in flow rate and the frequency converter is used, vacuum fluctuation increases. The proposed stabilisation device prototype can reduce the fluctuation in small milking plant but it is not suitable in large milking parlours.

Abstract

The research aim was to analyse the influence of velocity and size of markers on the accuracy of motion capture measurement utilising image processing with the use of OpenCV. On the basis of the obtained results, the usefulness of the applied measurement method in studying the kinematics of the human body while driving operating a wheelchair was determined. This article presents the test results for a low-budget motion capture measurement system for testing the kinematics of the human body in a single plane. The tested measuring system includes a standard activity camera Xiaomi Yi4K, expanded polystyrene markers with printed ArUco codes, and original software for marker position detection developed by the author. The analysis of the measurement method with regard to its applicability in biomechanical studies has highlighted several key factors: the number of measuring points, measurement accuracy expressed as a relative error and the limit velocity at which the marker trajectory is correctly represented. The article shows that the limit velocity of the marker is 2.2 m/s for 50x50 mm markers and 1.4 m/s for 30x30 mm markers. The number of measured points ranged from 233 to 2,457 depending on the marker velocity. The relative error did not exceed 5% for the marker velocities and thus provided a correct representation of its trajectory.