Search results for "electromagnetic [current]"
showing 10 items of 1008 documents
A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain).
2016
In this work we analyze the pigments used in the decoration of red and yellow motifs present in the portable art of the Parpallo Cave (Gandia, Spain), one of the most important Palaeolithic sites in the Spanish Mediterranean region. Energy dispersive X-ray fluorescence spectrometry (EDXRF) and spectrophotometry in the visible region (CIEL*a*b*color coordinates and spectral reflectance curves) were used to perform in situ fast analyses of the red and yellow motifs with portable equipment and to characterize their elemental composition and their colorimetric perception, respectively. According to the elemental composition, the intensity of the fluorescence iron signals in red and yellow motif…
A platform-independent software for the design and analysis of windings of rotating electrical machines
2014
In this paper the Authors present a highly modular and platform-independent software, being based on the MATLAB® programming environment, which is proposed as a valuable aid in the design and analysis of the windings of rotating electrical machines. Unlike the major part of the commercial software, the cases of both symmetric and asymmetric (unbalanced) windings with any number of phases are here considered. The software can perform a considerable amount of calculations in order to determine automatically the optimal structure of the winding starting from its specifications. It is also able to draw the winding map and gives the results of calculation for the harmonic winding factors. The re…
Ultracompact x-ray dosimeter based on scintillators coupled to a nano-optical antenna
2017
International audience; We show that nano-optical antennas are capable of controlling the luminescence induced by the absorption of x rays into matter. The x-ray-excited luminescence from a tiny scintillation cluster coupled to a horn nano-optical antenna is highly directed and determined by the antenna’s geometrical parameters. Directionality is sufficiently high to efficiently outcouple the x-ray-excited luminescence to a narrow single-mode optical fiber, thus enabling ultracompact fiber-integrated x-ray sensors. Our nano-optically driven approach offers the possibility of x-ray profiling and dosimetry in ultra-confined environments, opening up new avenues in the fields of x-ray imaging, …
Concentration dependence of the electro-optical spectra from two-dimensional aggregated chromophore systems
1991
The linear and the quadratic Stark effects have been employed to characterize aggregate formation of an amphiphilic cyanine dye mixed with arachidic acid in various concentrations within Langmuir-Blodgett multilayers. Two different electrode configurations with the electric field directions parallel and normal to the films have been employed to test the responses of the electronic spectra to external fields. The observations have been used to quantify the induced and static dipole moment changes on excitation of the chromophores. A comparison of the results obtained from different multilayer arrangements is suggestive of inter-layer couplings for the case of head-to-head configurations of t…
Transient optical absorption in KNbO3 crystals irradiated with pulsed electron beam
1997
Abstract Transient optical absorption spectra as well as absorption decay kinetics in pure, Mg- and Rb-doped KNbO 3 have been measured at RT after pulsed (10 ns, 0.27 MeV) electron beam irradiation. Three types of short-lived radiation defects are observed with bands peaking at ∼460 nm, ∼780 nm and > 1000nm. The relevant radiation-induced decay processes are discussed.
The M4 transitions of isomeric states
2015
Tässä pro gradu -tutkielmassa tutkitaan isomeeristen tilojen magneettisten M4-gammasiirtymien redusoituja matriisielementtejä. Tutkittavat siirtymät ovat venyneitä M4-siirtymiä kaksoisbeetahajoamisten massa-alueilla A=85-115 ja A=135-143. Tutkielman tarkoituksena on verrata kokeellisia ydinmatriisielementtejä kvasihiukkasmatriisielementteihin ja MQPM-teorian avulla laskettuihin matriisielementteihin. Kokeelliset matriisielementi lasketaan kokeellisesti määritettyjen arvojen avulla ja kvasihiukkas- sekä MQPM-matriisielementit määritetään tietokoneohjelmien avulla. Kokeellisten ja kvasihiukkasmatriisielementtien välinen suhde osoittautui olevan noin 0,29 ja kokeellisten ja MQPM-matriisielemen…
Resonant X-ray scattering in biological structure research
2007
The use of anomalous X-ray scattering of light elements like sulfur and phosphorus is of particular interest in biological structure research. These elements serve as native labels in proteins, nucleic acids and membranes. Their medium scattering power is drastically changed at their K absorption edges at wavelengths between 5 and 6 A where X-ray absorption excludes the use of open air diffractometers. The construction of a new diffractometer tunable to wavelengths between 1.2 and 7 A is presented. First results of anomalous scattering from sulfur in bacteriorhodopsin near the K absorption edge have been obtained recently. Their possible impact on crystallography will be considered. A compa…
Laser induced thermal profiles in thermally and optically thin films
1988
The temperature field generated by the weak absorption of a gaussian laser beam in an optically and thermally thin film bounded by two transparent plates is discussed. An analytical solution of the problem is presented together with an algorithm for the numerical integration. The influence of the finite thermal conductivity of the plates is shown in an example.
Search for the exotic Θ+ resonance in the NOMAD experiment
2006
12 pages, 16 figures.-- PACS nrs.: 13.15.+g; 13.60.Le; 13.87.Fh; 14.40.Ev.-- ISI Article Identifier: 000243973100007.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ex/0612063.-- et al.
Radiation processes in oxygen-deficient silica glasses: Is ODC(I) a precursor of E′-center?
2006
Abstract The accumulation of radiation-induced defects under non-destructive X-ray and destructive cathodoexcitation was studied in pure silica KS-4V glasses possessing an absorption band at 7.6 eV. The correspondence between the existence of this band and the creation of the E′-center by radiation was checked. Detection of induced defects was accomplished by measurement of the luminescence during irradiation, post irradiation afterglow or phosphorescence, induced optical absorption, and thermally stimulated luminescence. In all samples, these observed phenomena associated with charge trapping and recombination on the oxygen-deficient luminescence center. Others centers of luminescence were…