Search results for "Spectrum"
showing 10 items of 2043 documents
A noise analyzer for monitoring static electrification current
2005
Abstract This paper presents a static electrification current signal analyzer used for measuring and processing of the variable component of the changes in electrostatic charge that occur on a solid-body/liquid boundary interface. Due to high sensitivity and low uncertainty, the analyzer allows a precise evaluation of the phenomenon generated. The device operates in a spinning-disk system. The tests carried out indicate that it is possible to measure random components which depend, to a large extent, on hydrodynamic conditions and on the properties of the liquid phase. The device can be applied to the testing of transformer oils. It can be also used for measurements of other liquids having …
Experimental assessment of application of gravimetric measurements for pneumatic conveying in horizontal pipelines
2008
Abstract Available theoretical considerations and practical experiments usually concern aspiration in the vertical pipelines, where the procedure of making measurements is universally known and it does not express any reservations. However, it is often necessary to conduct test in the systems of horizontal conveying of solgas, where the conditions of taking a representative sample, even for the sake of the significant effect of the gravitational force, many vary from those suggested for measurements in the systems with vertical flow. The present paper contains the results of tests which determine usability of the gravimetric method in measurements of flow parameters of two-phase gas–solid m…
Design of a real-time spectroscopic rotating compensator ellipsometer without systematic errors
2014
6th International Conference on Spectroscopic Ellipsometry (ICSE), Kyoto, JAPAN, MAY 26-31, 2013; International audience; We describe a spectroscopic ellipsometer in the visible domain (400-800 nm) based on a rotating compensator technology using two detectors. The classical analyzer is replaced by a fixed Rochon birefringent beamsplitter which splits the incidence light wave into two perpendicularly polarized waves, one oriented at +45 degrees and the other one at-45 degrees according to the plane of incidence. Both emergent optical signals are analyzed by two identical CCD detectors which are synchronized by an optical encoder fixed on the shaft of the step-by-step motor of the compensato…
Measurement technique for real-time and low-cost biosensing using photonic bandgap structures
2011
We present a sensing technique based on using photonic bandgap structures where only the output power is monitored, without the need of tunable sources or spectrum analyzers, thus providing a real-time and low-cost system.
Detection of lung cancer bio-markers in human breath using a micro-fabricated air analyzer
2015
International audience; The analysis of volatile organic compounds (VOCs) that are linked to lung cancer is a very promising way in medical diagnostics because it is non-invasive and potentially inexpensive. In that sense, a silicon micro-analytical platform consisting of a three-dimensional micro-preconcentrator coupled to a silicon spiral gas chromatographic micro-column was built. A metal oxide-based gas sensor acted as a miniaturized gas detector. This system allowed selective detection of VOCs at the sub-ppm level. The present study is focused first on the chromatographic air analyzer fabrication and second on the selection of an appropriate adsorbent. Various adsorbents such as activa…
Single-Hemisphere Photoelectron Momentum Microscope With Time-of-Flight Recording
2020
Photoelectron momentum microscopy is an emerging powerful method for angle-resolved photoelectron spectroscopy (ARPES), especially in combination with imaging spin filters. These instruments record kx-ky images, typically exceeding a full Brillouin zone. As energy filters double-hemispherical or time-of-flight (ToF) devices are in use. Here we present a new approach for momentum mapping of the full half-space, based on a single hemispherical analyzer (path radius 225 mm). Excitation by an unfocused He lamp yielded an energy resolution of 7.7 meV. The performance is demonstrated by k-imaging of quantum-well states in Au and Xe multilayers. The alpha-square-aberration term (alpha: entrance an…
Quantitative spin polarization analysis in photoelectron emission microscopy with an imaging spin filter.
2012
Abstract Using a photoelectron emission microscope (PEEM), we demonstrate spin-resolved electron spectroscopic imaging of ultrathin magnetic Co films grown on Cu(100). The spin-filter, based on the spin-dependent reflection of low energy electrons from a W(100) crystal, is attached to an aberration corrected electrostatic energy analyzer coupled to an electrostatic PEEM column. We present a method for the quantitative measurement of the electron spin polarization at 4×10 3 points of the PEEM image, simultaneously. This approach uses the subsequent acquisition of two images with different scattering energies of the electrons at the W(100) target to directly derive the spin polarization witho…
Deconvolution of XPS spectra
1991
The resolution of XPS spectra is limited mainly by instrumental parameters like the spectral line width of the exciting X-ray source and the finite energy resolution of the electron analyzer. If the line broadening functions resulting from the instrumental setup can be estimated and expressed by a spectrometer function, a mathematical recalculation of the intrinsic signal is possible by deconvolution. With the method presented in this paper, a resolution enhancement by a factor of 3 can be obtained. Measured spectra of physically correlated spin orbit doublets have been deconvoluted, and it is shown, that the intensity ratios and the positions are comparable with results obtained by highly …
<title>High-frequency electrodeless light sources for application</title>
2001
The high-frequency electrodes light sources (HFELS) are widely used as bright radiators of narrow and intensive spectral lines covering spectral region from VUV to IR. In this work we shall give a short overview of our experience in preparation of HFELS, containing He, H, Rb, Hg, Zn, Pb, As, Sb, Bi, Tl, Hg-Cd, Hg-Zn, Hg-Cd-Zn, Se-Te for different applications. Special attention would be paid for HFELS use in Zeeman mercury analyzer, in Atomic absorption analyzer and Angle and glass refractive index measurement system.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Analysis of pattern recognition by man using detection experiments.
1981
This paper addresses the problem of analyzing biological pattern recognition systems. As no complete analysis is possible due to limited observability, the theoretical part of the paper examines some principles of construction for recognition systems. The relations between measurable and characteristic variables of these systems are described. The results of the study are: 1. Human recognition systems can always be described by a model consisting of an analyzer (FA) and a linear classifier. 2. The linearity of the classifier places no limits on the universal validity of the model. The principle of organization of such a system may be put into effect in many different ways. 3. The analyzer f…