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Pozorování zubní skloviny a dentinu v SEM
Wandrol, Petr ; Roubalíková, L. ; Autrata, Rudolf
The purpose of this study was to investigate whether the acidic monomer based on the phosphoric acid ether acrylate can create the same retentive pattern in enamel and dentin as the conventional treatment with the 37% phosphoric acid. The surface of enamel in the AdHeSe group was slightly undulated, the retentive pattern was regular and moderate. In the TotalEtch group more irregularities and a clearer retentive pattern were observed. The dentin surface was similar in both groups- it was clean without the smear layer, the dentin tubuli were open, the collagen network was seen on the dentin surface as well as in the dentin tubuli.
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Angular distribution of backscattered electrons signal in Environmental Scanning Electron Microscopy
Wandrol, Petr
The aim of this work was to verify an influence of the collection solid angle on a magnitude of detected signal. The presented results of measurement were gained by an observation of the specimen of carbon covered with a thin layer of gold. The primary beam accelerating voltage was 20kV. The collection solid angle was changed by application of aluminium masks with aperture diameters 2,3,4,8,16 mm mounted on scintillator. As a working environment in the specimen chamber air and saturated water vapour were used.
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Study of contrast mechanisms in environmental scanning electron microscopy
Wandrol, Petr
The main goal of the work is study of contrast materials in environmental scanning electron microscopy. I will concentrate to the design and construction of the original detector of secondary electrons, which is not influenced by backscattered electrons as well as to scintillation detector of backscattered electrons on the basis of single-crystal YAP in the dissertation work. For successful solution of the topic it will be necessary to manage the theory of the influence of magnetic fields on trajectories of electrons. The knowledge of the software SIMION, version 7.0 will be necessary too, together with studying of the theory for assessment of suitable vacuum conditions in differential chambers.
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Trajektorie signálních elektronů v nízkonapěťovém BSE detektoru
Wandrol, Petr ; Autrata, Rudolf
Nowadays the development of the image formation in scanning electron microscope (SEM) is oriented to the use of scanning electron microscopes with low accelerating voltage of the primary beam (LV SEM). Secondary electrons (SEs) for topographical contrast observation and backscattered electrons (BSEs) for material contrast observation are the main components of the detected signal in LV SEM. While the secondary electrons can be detected either by Everhart-Thornley scintillation detector or by the "in lens" SE detector, the detection of backscattered electrons (BSEs) in LV SEM is an unsolved problem yet
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