|
|
Sample preparation and their measurement by EDS methods
Kostelník, Tomáš ; Jaššo, Kamil (referee) ; Čudek, Pavel (advisor)
This bachelor´s thesis is focused on preparation and analysis of samples by energy dispersive spectroscopy using scanning electron microscopy. In the theoretical the main differences between environmental scanning electron microscopy and scanning electron microscopy are described. There is also a description of basic knowledge regarding energy dispersive spectroscopy. The generation and detection of signals arising from the interaction of a beam of primary electrons with a sample is also explained, with emphasis on the description, generation and distribution of these signals. The experimental part is focused on sample preparation and analysis.
|
|
| |
|
|
Evaluation of structures of solder joint with printed board circuit
Jakubec, Jiří ; Jirák, Josef (referee) ; Černoch, Pavel (advisor)
The theoretical part of the diploma thesis deals with the basic principles of the scanning electron microscope and the environmental scanning electron microscope. A description of the signals generated by an electrons incidence onto a specimen and detection options of these signals in the mentioned microscopes is included in the work. The experimental part of the work concerns an examination of a quality of several joints soldered by different methods on the printed circuit boards after different stresses by use of a visual check and the instruments of the light microscope and the environmental scanning electron microscope. The acquired data are evaluated and summarized.
|
|
|
Scintillation SE Detector for Variable Pressure SEM
Tihlaříková, Eva ; Neděla, Vilém (referee) ; Jirák, Josef (advisor)
This project deals with the theme of environmental scanning electron microscopy (EREM). This method allows the examination of insulators and wet specimens without pretreatment and modification like drying and metallization. The principle of this method consists in using higher pressure in a specimen chamber. The pressure is within the range of 100 – 200 Pa. However, the pressure in the specimen chamber restricts the signal detection interference. The objective of the work is to explore the possibility of interference in secondary electron route detection by way of electrostatic field. The electrostatic field was realized with the system consisting of four electrodes located in front of the scintillation detector. It should have interfered the secondary electron´s trajectory to the detector chamber. The optimization of voltage on the electrodes was made by simulation program called SIMION. The simulation results were experimentally verified with laboratory EREM.
|
|
|
Application of Environmental Scanning Electron Microscopy (ESEM) in the field of miniatures´ analysis: methodology for specific use in miniature painting research
Hradil, David ; Hradilová, J. ; Neděla, Vilém ; Tihlaříková, Eva
The methodology deals with a completely new, unused procedure of non-invasive analysis of painted portrait miniatures, namely an environmental scanning electron microscope with energy-dispersive X-rays. spectrometer(EREM-EDS). EREM, unlike the conventional scanning electron microscope (REM), allows the analysis of ivory painting, which is not possible in a vacuum or low gas pressure environment, where there is a risk of deformation and damagedue to drying of this biological material. The methodology is divided into two parts - the first describes the study of morphological details at high magnification (eg. the possibility of distinguishing different types of biological substrates), the second is the implementation of elemental analysis in high spatial resolution.
|
|
|
Sample preparation and their measurement by EDS methods
Kostelník, Tomáš ; Jaššo, Kamil (referee) ; Čudek, Pavel (advisor)
This bachelor´s thesis is focused on preparation and analysis of samples by energy dispersive spectroscopy using scanning electron microscopy. In the theoretical the main differences between environmental scanning electron microscopy and scanning electron microscopy are described. There is also a description of basic knowledge regarding energy dispersive spectroscopy. The generation and detection of signals arising from the interaction of a beam of primary electrons with a sample is also explained, with emphasis on the description, generation and distribution of these signals. The experimental part is focused on sample preparation and analysis.
|
|
|
Interactions of microscopic fungi and testate amoebae in Norway spruce litter
Konvalinková, Tereza ; Koukol, Ondřej (advisor) ; Nováková, Alena (referee)
Both testate amoebae and fungi are common inhabitants of coniferous litter. Their interactions in this environment were rarely studied, although they reach high biodiversity and can play a significant role in nutrient cycling in this environment. In this study, a cultivation of litter needles in the damp chambers was used to investigate interactions between fungi and testate amoebae. Observation of spruce litter needles in environmental scanning electron microscope was used to better characterize testate amoebae communities directly on the needles. Additionally, two experiments changing the biotic conditions in the microcosm were used to follow a principle of the interactions. Three species of testate amoebae from litter needles were able to colonize the filter paper on the bottom of the damp chambers. Occurrence of Phryganella acropodia and Assulina muscorum on the filter paper was significantly fuelled by the presence of mycelium. Assulina muscorum was associated with the fungal spores and Arcella discoides was attracted by sporulating colonies of Cladosporium spp. in the damp chambers. By contrast, no association of putatively mycophagous Phryganella acropodia with fungal spores was observed. Arcella discoides was attracted both by live and death mycelium in additional experiment. Interestingly, the...
|
|
|
Interactions of microscopic fungi and testate amoebae in Norway spruce litter
Konvalinková, Tereza ; Koukol, Ondřej (advisor) ; Nováková, Alena (referee)
Both testate amoebae and fungi are common inhabitants of coniferous litter. Their interactions in this environment were rarely studied, although they reach high biodiversity and can play a significant role in nutrient cycling in this environment. In this study, a cultivation of litter needles in the damp chambers was used to investigate interactions between fungi and testate amoebae. Observation of spruce litter needles in environmental scanning electron microscope was used to better characterize testate amoebae communities directly on the needles. Additionally, two experiments changing the biotic conditions in the microcosm were used to follow a principle of the interactions. Three species of testate amoebae from litter needles were able to colonize the filter paper on the bottom of the damp chambers. Occurrence of Phryganella acropodia and Assulina muscorum on the filter paper was significantly fuelled by the presence of mycelium. Assulina muscorum was associated with the fungal spores and Arcella discoides was attracted by sporulating colonies of Cladosporium spp. in the damp chambers. By contrast, no association of putatively mycophagous Phryganella acropodia with fungal spores was observed. Arcella discoides was attracted both by live and death mycelium in additional experiment. Interestingly, the...
|
|
|
Detection of Signal Electrons in High Pressure Conditions in Environmental Scanning Electron Microscopy
Neděla, Vilém ; Jirák, Josef (advisor)
The thesis deals with the study of properties of a new system for detection of true secondary and backscattered electrons in high pressure conditions of the specimen chamber of a newly built environmental scanning electron microscope AQUASEM II. Detection system contains three detectors. For the first time is introduced and analyzed the working principle of ionisation detector with electrostatic separator, which is in many experiments compared with ionisation detector of secondary electrons. Experimentally demonstrated are unique properties of this detection system, especially the ability of energy separation of detected signal electrons. For the various working conditions are also analyzed signal levels detected by the BSE YAG detector, which is designed as a part of the new detection system and which worked together with both ionisation detectors.
|
|
| |
guest ::
