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Realtionship between protein content, bread-making quality and wheat endosperm microstructure
Burešová, I. ; Dvořáková, P. ; Hřivna, L. ; Mika, Filip
Microstructure is an organization of structural elements and enables to understand the connections between microstructure – physical properties – food quality. The main composite of the wheat endosperm is starch and the dried endosperm consists of cells filled by the protein and starch grains. The aim of work was to define the relationship between wheat endosperm microstructure, protein content and bread-making quality. Winter wheat cultivars (Triticum aestivum L.) of different bread-making quality were divided into 6 groups in agreement with the visual evaluation of the microstructure. Criteria were coherence, thickness of the protein matrix and immersion of the starch grains into protein matrix. Significantly lower protein content and inferior bread-making was found for endosperm in which the starch grains were not visually recognized, protein matrix was discontinuous, thick and 2D. Conversely the higher protein content and better bread-making quality could be associated with thin protein matrix.
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Displacement Interferometry in Passive Fabry-Perot Cavity
Lazar, Josef ; Číp, Ondřej ; Oulehla, Jindřich ; Pokorný, Pavel ; Fejfar, Antonín ; Stuchlík, Jiří
We present techniques oriented to improvement of precision in incremental interferometric measurements of displacements over a limited range where the atmospheric wavelength of the coherent laser source is either directly stabilized to a mechanical reference or is corrected to fit to the reference. This may represent a reduction of uncertainty linking the laser wavelength not to indirectly evaluated refractive index but to the setup mechanics which cannot be completely eliminated. Here we suggest an approach where the traditional interferometers are replaced by a passive Fabry-Perot cavity with position sensing using an intracavity transparent photodetector.
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Scanning Probe Microscopy: Measuring on Hard Surfaces
Matějka, Milan ; Urbánek, Michal ; Kolařík, Vladimír
During a measurement by scanning probe microscopy (SPM) an image artifacts can appear in a measurement data. The source of image artifacts during an SPM measurement could be in parts of the SPM tool: mechanical system, piezoelectric crystal, scanner electronic. However, the main source of image artifact is the probe tip geometry and properties of the sample. For example, probe wearing, which occurs during the contact measurement on a sample with a hard surface, could result in heavy probe shape change, causing probe-related image artifacts. Measurement could appear problematic on a sample with periodical relief structure (e.g. gratings with sub 10 μm periodicity) prepared in hard materials (e.g. silicon), when the structure height is greater than about 500 nm. In this case, probe can easily get struck during the scanning, on the hard surface as well as at the high aspect ratio relief structure, causing image artifact thus reducing measurement quality.
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SPM Nanoscratching in the Sub 100 nm Resolution
Urbánek, Michal ; Kolařík, Vladimír ; Matějka, Milan
Scanning probe microscopy (SPM) is tool basically used for surface characterization. Besides that, it offers several lithographic methods (e.g. nanoscratching) to prepare structures in the sub 100 nm resolution. The nanoscratching using SPM offers a method for patterning of surface with a very high resolution based on near field interaction. By this method some tiny marks or taggants could be prepared. Therefore we used the SPM nanoscratching for preparation of nanostructures in thin soft polymer films by various tips. Nanoscratching regime of SPM is possible to operate in contact and close contact modes. In the contact mode we prepared an array of stamps with a variable size, where dimensions and depth dependency on number of pixels were inspected. For writing of these structures we used polymer films with different softness (e.g. PMMA, SU-8) and various values of setpoint, which are responsible for structures deepness.
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Soubor softwarových nástrojů pro ultrazvukové perfuzní zobrazování
Mézl, M. ; Jiřík, Radovan
Tento článek prezentuje soubor softwarových nástrojů, který je používán pro perfuzní analýzu ultrazvukových kontrastních sekvencí. Samotný program se skládá ze šesti funkčních bloků, které obsluhují import dat, registraci obrazů, převod na koncentraci kontrastní látky, výběr oblasti zájmu, perfuzní analýzu a vizualizaci dat. Odhad perfuzních parametrů je založen na parametrické multikanálové dekonvoluci. V současné době je tento software používán na vybraných klinických pracovištích.
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Energiové ztráty ve vodivé vrstvě scintilačního monokrystalu
Flodrová, E. ; Neděla, Vilém
This work deals with study of mechanisms of loosing signal electron energy in the single crystal scintillator which depend on the type and thickness of the conductive layer on the surface. The types and amount of loss processes will he described. Monte Carlo simulations were performed for quantification of energy loss for individual processes and materials which are commonly used in scintillations detection systems.
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Multiple Probe Photonic Force Microscopy
Jákl, Petr ; Šerý, Mojmír ; Zemánek, Pavel
Single beam optical trap (also known as optical tweezers) is created by a laser beam that is tightly focused by microscope objective with high numerical aperture. A dielectric particle in water medium is then dragged by optical forces to place of the highest optical intensity, i.e. to the laser beam focus. Photonic force microscopy (PFM) is a technique that utilizes optical tweezers for confining the local probe, usually a dielectric particle of a sub-micron diameter. I.e. PFM belongs to the of large family of scanning probe microscopy (SPM) techniques. We have used fluorescently labeled polymer sphere in order to conveniently measure the distance between the particle center and the focal point of the laser beam. To make the measurement more precise, we have measured two-photon-fluorescence, which is quickly decreasing with the probe-focus distance.
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Scanning Very Low Energy Electron Microscopy
Müllerová, Ilona ; Hovorka, Miloš ; Mikmeková, Šárka ; Pokorná, Zuzana ; Mikmeková, Eliška ; Frank, Luděk
Recent developments in applications of the scanning very low energy electron microscopy in selected branches of materials science are reviewed. The examples include visualization of grains in conductive polycrystals including ultrafine grained metals, identification of the local crystal orientation upon reflectance of very slow electrons, transmission mode with ultrathin free-standing films including graphene, acquisition of a quantitative dopant contrast in semiconductors, and examination of thin surface coverages.
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