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Effect of different management on the production, structure and chemical composition of abovegroung biomass in the Mlýnský potok catchment.
TRUHLÁŘ, Martin
The aim of the thesis is to assess the changes in production and structure of surface biomass (the proportion of grasses, clovers and other plants) and its chemical compound in scythed and pastured grass areas in the monitored areas in the Mlýnský potok basin in years 2012 and 2014. The area is situated on the right bank of Lipno dam in Pasečná land register, 784 820 meters above sea-level. There were established three permanent sampling points in the pastured as well as scythed areas in the Mlýnský potok basin. Four samples of biomass from the area of 1 sq m were collected in each of these sampling points. These were collected on 20th June 2012, 11th September 2012, 17th June 2014 and 10th September 2014. The collected biomass was then divided into agro-botanical groups (grasses, clovers and other plants) and afterwards it was dried and weighed. The chemical analysis was conducted by a certified laboratory AGRO-LA, Ltd. in Jindřichův Hradec. The aim of the analysis was to find out the amount of nitrogen, phosphorus, potassium, magnesium and calcium. By assessing the development of the overall production of the biomass in 2012 and 2014 in the sampling area we found out a considerable decline of biomass in scythed areas and an increasing difference in the average amount of biomass between scythed and pastured areas during the monitored period. These findings were assessed as statistically conclusive. By assessing the development of overall proportions of the agro-botanical groups we could see a substantial decrease in grasses and on the other hand an increase of clovers and other plants in scythed areas compared to pastured areas. The difference between the proportion of grasses and other plants proved to be statistically conclusive. By assessing the development in difference of the overall average amount of nitrogen in the biomass, there emerged a considerable increase in the amount of nitrogen regardless the way of management. As far as phosphorus is concerned, we found out a decreasing difference in its amount between scythed and pastured areas. The amount of potassium was considerably lower in scythed areas, whereas calcium showed the exact opposite. Statistically conclusive were the findings of substantial increase of nitrogen in the surface biomass and also the changes in the amount of potassium and calcium due to the management. By evaluating these outcomes we confirmed that the permanent grass areas have a very variable productive and structural potential which holds true also for their chemical compound.
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A Comparison of Different Measurement Method of Mechanical Properties of Al Thin Film
Truhlář, M. ; Buršíková, V. ; Sobota, Jaroslav ; Kruml, Tomáš
The paper compares two different methods for testing of metallic thin films: microcompression test and nanoindentation. Microcompression test is one possibility how to perform mechanical tests on a very small scale. This method requires preparation of a small cylindrical specimen (micropillar) of micrometric size by FIB and execution of a compression test using nanoindenter device equipped with a flat diamond punch. Stressstrain curves of the thin films were obtained from such tests. Nanoindentation tests were then conducted to compare the results on the same films. Two different metal thin films – AlCuW, AlCuSi with thickness 2 .mu.m and grain size 3.8 .mu.m in average were prepared by PVD method. In this paper, we announce the results of measurements, a comparison of the results obtained by each method and identify advantages and limitations of the methods.
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Effect of different management on the production and structure of biomass in the Mlýnský potok catchment (Lipensko).
TRUHLÁŘ, Martin
The aim of the thesis is to compare the production and structure of biomass (the proportion of grasses, clovers and other plants) in selected scythed and pastured permanent grass areas in the Mlýnský potok (Mill stream) basin. The monitored area is situated on the right bank of Lipno dam in Pasečná land register, 784-820 meters above sea-level. There were established three permanent sampling points in the pastured as well as scythed area in Mlýnský potok basin. Four samples of biomass from the area of 1 sq m were collected in each of these sampling points. In 2012 the samplings were collected on 20th June and 11th September. The collected biomass was then divided into agrobotanical groups (grasses, clovers and other plants) and afterwards it was dried and weighed. In the concerned area, the production from the pastured growth was considerably higher than from the scythed one. Structure of biomass, i.e. the proportion of grasses, clovers and plants, was in both areas comparable, only clovers in the scythed area had greater rates dispersion.
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Determination of mechanical properties from microcompression test
Truhlář, Michal ; Kruml, Tomáš ; Kuběna, Ivo ; Petráčková, Klára ; Náhlík, Luboš
This paper describes a microcompression test of Al - 1.5 wt. % Cu thin film deposited on Si substrate. Microcompression combines the sample preparation with the use of ion focused beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared using FIB. The diameter of pillars was about 1.3 μm and their height was about 2 μm (equal to the film thickness). Stress-strain curves of the thin film were obtained. The results depend on crystallographic orientation of pillar. The paper is focused to an attempt to determine as precisely as possible Young modulus of the film using experimental data and finite element modelling.
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Estimation of mechanical properties of thin Al surface layer
Petráčková, Klára ; Kuběna, Ivo ; Truhlář, Michal ; Náhlík, Luboš ; Kruml, Tomáš
The paper describes a new method for testing of thin layers, so-called microcompression test. As an example determination of Al thin film properties deposited on Si substrate is introduced in the paper. Microcompression combines the sample preparation with the use of focused ion beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared in Al film using FIB. The typical diameter of pillars was about 1.3 μm and their height was about 2 μm. The results depend on crystallographic orientation of pillar. Stress-strain curves of the thin film were obtained. Experimentally measured data on pillars needs correction to obtain undistorted material properties of Al thin film. A necessary correction using finite element modeling is suggested in the paper. The paper contributes to a better characterization of very thin surface layers and determination of their mechanical properties.
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