33 research outputs found
Systematic analytics of non-linear deviations by established standards and a new generation of 3D standards
No full textA novel pitch evaluation of one-dimensional gratings based on a cross-correlation filter
No full textIf one-dimensional (1D), p–period and arbitrarily structured grating position-related topographical signals coexist with noise, it is difficult to evaluate the pitch practically using the centre-of-gravity (CG) method. The Fourier-transform-based (FT) method is the most precise to evaluate pitches; nevertheless it cannot give the uniformity of pitches. If a cross correlation filter ̶ a half period of sinusoidal waveform sequence (pT period), cross-correlates with the signals, the noise can be eliminated if pT is equal to p. After cross-correlation filtering, the distance between any two adjacent waveform peaks along the direction perpendicular to 1D grating lines is one pitch value. The pitch evaluation based on the cross-correlation filtering together with the detection of peaks position is described as the peak detection (PD) method in this paper. The pitch average and uniformity can be calculated by using the PD method. The computer simulation has indicated that the average of pitch deviations from the true pitch and the pitch variations are less than 0.2% and 0.2% for the sinusoidal and rectangular waveform signals with up to 50% uniform white noise, less than 0.1% and 1% for the sinusoidal and rectangular waveform signals and 0.6% and 2.5% for the triangular waveform signal if three waveform signals are mixed with Gaussian white, binomial and Bernoulli noise up to 50 % in standard deviation, one probability and trial probability respectively. As the examples, a highly oriented pyrolytic graphite (HOPG) with 0.246 nm distance between atoms and a 1D grating with 3000 nm nominal pitch are measured by a ultra-high vacuum scanning tunneling microscope (UHV STM) and a metrological atomic force microscope (AFM) respectively. After the position-related topographical signals are cross-correlation filtered, the 0.240 nm and 3004.11 nm pitches calculated by using the PD method are very close to the 0.240 nm and 3003.34 nm results evaluated by the FT method
A new quantitative height standard for the routine calibration of a 4-quadrant-large-angles-BSE-detector
No full textEntwicklung einer Kalibrierrichtlinie für Rastersondenmikroskope
No full textS.295-306Nicht nur in Forschung und Entwicklung, sondern auch zunehmend in der industriellen Fertigung kommen immer kleinere funktionelle Strukturen bis hin zu nanotechnologischen Komponenten zum Einsatz. Dadurch erlangt die Rastersondenmikroskopie auch als quantitatives Messverfahren wachsende Bedeutung und damit die Frage, wie diese Geräte zu kalibrieren sind. Dieser Bericht zielt deshalb darauf ab, den gegenwärtigen Stand der Diskussionen zu einer zukünftigen Kalibrierrichtlinie zusammenzufassen und somit ein mögliches Schema für die quantitative Charakterisierung von SPM-Messsystemen vorzustellen. Kritische Punkte werden dabei teilweise auch anhand von praktischen Beispielen diskutiert.72Nr.
NanoWorkshop 2018: Workshop on Reference Nanomaterials
No full textThe Scope of the Workshop was to provide a forum for discussion on progress in development, characterisation and application of reference nanomaterials. Results of recently finished national and international research projects have been presented. Moreover, the need for future developments have been addressed.
Attendees of the Workshop were expected to be experts from academia, research institutes, regulatory bodies and industry working or interested in the area of reference nanomaterials.
The following structure of Workshop was planned: the main focus of the first day was on reference material needs and development, while the second day was focussed on reference materials characterisation and standardisation.
Over 111 participants from 13 countries and the European Joint Research Centre have registered for the Workshop with 16 platform presentations and 42 poster contributions grouped in 2 sessions and 10 topical areas.
A summary of the observations, analysis and conclusions of the Workshop is made including an overview table of links to information on existing reference nanomaterials
Mangiferin Affects Melanin Synthesis by an Influence on Tyrosinase: Inhibition, Mechanism of Action and Molecular Docking Studies
No full textMangiferin is a strong antioxidant that presents a wide range of biological activities. The aim of this study was to evaluate, for the first time, the influence of mangiferin on tyrosinase, an enzyme responsible for melanin synthesis and the unwanted browning process of food. The research included both the kinetics and molecular interactions between tyrosinase and mangiferin. The research proved that mangiferin inhibits tyrosinase activity in a dose-dependent manner with IC50 290 +/− 6.04 µM, which was found comparable with the standard kojic acid (IC50 217.45 +/− 2.54 µM). The mechanism of inhibition was described as mixed inhibition. The interaction between tyrosinase enzyme and mangiferin was confirmed with capillary electrophoresis (CE). The analysis indicated the formation of two main, and four less significant complexes. These results have also been supported by the molecular docking studies. It was indicated that mangiferin binds to tyrosinase, similarly to L-DOPA molecule, both in the active center and peripheral site. As it was presented in molecular docking studies, mangiferin and L-DOPA molecules can interact in a similar way with surrounding amino acid residues of tyrosinase. Additionally, hydroxyl groups of mangiferin may interact with amino acids on the tyrosinase external surface causing non-specific interaction
Evidence of electron neutrino appearance in a muon neutrino beam
No full textThe T2K Collaboration reports evidence for electron neutrino appearance at the atmospheric mass splitting, vertical bar Delta m(32)(2)vertical bar approximate to 2.4 X 10(-3) eV(2). An excess of electron neutrino interactions over background is observed from a muon neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK) detector 295 km from the beam's origin. Signal and background predictions are constrained by data from near detectors located 280 m from the neutrino production target. We observe 11 electron neutrino candidate events at the SK detector when a background of 3.3 +/- 0.4(syst) events is expected. The background-only hypothesis is rejected with a p value of 0.0009 (3.1 sigma), and a fit assuming nu(mu) -> nu(e) oscillations with sin (2)2 theta(23) = 1, delta(CP) = 0 and vertical bar Delta m(32)(2)vertical bar = 2.4 X 10(-3) eV(2) yields sin (2)2 theta(13) = 0.088(-0.039)(+0.049)(stat + syst)
