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Nanometrology coordinate measurement machines uncertainties caused by frequency fluctuations of the laser
Hrabina, Jan ; Lazar, Josef ; Číp, Ondřej
One of considerable sources of displacement measurement uncertainty in nanometrology systems such as multidimensional interferometric positioning for local probe microscopy is the influence of amplitude and especially frequency noise of a laser source which powers the interferometers. We investigated the noise properties of several laser sources suitable for interferometry for micro- and nano-CMMs (coordinate measurement machines) and compared the results with the aim to find the best option. The influences of amplitude and frequency fluctuations were compared together with the noise and uncertainty contributions of other components of the whole measuring system. Frequency noise of investigated laser sources was measured by two approaches – at first with the help of frequency discriminator (Fabry-Perot resonator) converting the frequency (phase) noise into amplitude one and then directly through the measurement of displacement noise at the output of the interferometer fringe detection and position evaluation. Both frequency noise measurements and amplitude noise measurements were done simultaneously through fast and high dynamic range synchronous sampling to have the possibility to separate the frequency noise and to compare the recorded results.
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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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Mechanisms involved in sodium uptake activation by the Tumor Necrosis Factor-derived TIP peptide
DULEBO, Alexander
The Tumor Necrosis Factor derived-TIP peptide is a small 17 amino acids cyclic peptide with lectin-like activity, that possesses several therapeutically relevant biological activities, among which is activation of alveolar liquid clearance in both healthy and injured lungs in vivo. Accumulation of fluid in the lungs? alveoli and interstitial spaces is a life-threatening condition called pulmonary edema. The mortality rate due permeability pulmonary edema, accompanied by a dysfunction of the alveolar/capillary barrier, is high because no effective treatment lacking side effects exists nowadays. It is known that the TIP peptide is able to activate vectorial Na+ transport ? which mediates lung liquid clearance. However, the mechanism of action of remains elusive. The aim of this thesis was to investigate the initial steps of interaction between the TIP peptide and airway epithelial cells. Numerous novel methods and single-molecule techniques were used to unravel: (i) how the TIP peptide interacts with the molecules on the apical side of the lung epithelial cells; (ii) whether the TIP peptide need to be internalized inside of the cells to trigger its effects; (iii) the nature of the interaction between the TIP peptide and its putative receptor(s); (iv) the putative receptor(s) for the TIP peptide on the apical surface of the lung epithelial cells.
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Electrochemical sensor: Mediator Deposition by drop evaporation
Mansfeldová, Věra ; Janda, Pavel ; Tarábková, Hana
Among many different kinds of electrode surface modification procedures, the surface coating by vaporized mediator solution is still used as a simple and effective method for preparation of sensing electrode. Surface of glassy carbon (GC) is often used as a supporting collector, but it requires polishing, rinsing and sonication prior to mediator deposition. In this paper, we present common methods of modification of highly oriented pyrolytic graphite (HOPG) and GC surface, respectively, from the point of surface nanomorphology investigated by atomic force microscopy.
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Electrode coating by chemical mediator: The atomic force microscopy study of surface nanomorphology
Mansfeldová, Věra ; Janda, Pavel ; Tarábková, Hana
Among many different kinds of electrode surface modification procedures, the surface coating by vaporized mediator solution is still as a simple and effective method for preparation of sensing electrode. Surface of glassy carbon (GC) is often used as a supporting collector, but it requires polishing, rinsing and sonication prior to mediator deposition. In this paper, we present common methods of modification of highly oriented pyrolytic graphite (HOPG) and GC surface, respectively, from the point of surface nanomorphology investigated by atomic force microscopy (AFM).
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Polished Silver Solid Amalgam Electrode
Fadrná, Renata
The polished silver solid amalgam electrode (p-AgSAE) seems to be a suitable alternative to hanging mercury drop electrode (HMDE). The structure of electrode material and working electrode surface were analyzed by RTG diffraction, atomic forces microscopy (AFM) and scanning electron microscopy (SEM). It was found that silver amalgam has crystalline structure (without the presence of different phases), any liquid mercury is not presented on the electrode surface and also mercury is not evaporated from the amalgam. p-AgSAE was applied for the determination of inorganic cations (Cu2+, Pb2+, Cd2+, Zn2+) and anions (NO3-, SCN-), amino acids (cysteine, cystin), nitro compounds (2,4´-dinitritoluene, 1,3´-dinitrobenzene, 2-nitronaftalene), aldehydes (benzaldehyde), vitamin C and purine bases of DNA (adenine, guanine) up to now.
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