Search results for "electromagnetic [calorimeter]"
showing 10 items of 1071 documents
Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly
2018
Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromag…
<title>Multiphoton-absorption-induced structural changes in fused silica</title>
1991
The basic properties (light refractive index, density, mechanical strength, etc.) of fused silica are changed by the influence of high-intensity light from the glass transparency region capable of generating excitons by multiphoton absorption. The self-trapped exciton decay near the microcavity in the fused silica structure leads to the stable elementary intrinsic defect pair (nonbridging oxygen atom and three-fold-coordinated silicon atom) generation. At the large- enough light intensities near such a microcavity with a defect, the next exciton can be self- trapped. Then the next elementary defect can appear in the microcavity, and a chemical bond between it and the previously generated de…
Luminescence center excited state absorption in tungstates
2001
The excited state absorption of intrinsic luminescence center (self-trapped exciton) in tungstates (CaWO4, ZnWO4, PbWO4 and CdWO4) was studied. The transient absorption and luminescence spectra, decay kinetics and lifetime dependencies on temperature have been measured. The model of self-trapped exciton and nature of observed absorption bands were discussed.
Magnetic Field and Short-Circuit Reactance Calculation of the 3-Phase Transformer with Symmetrical Amorphous Core
2006
Magnetically symmetric, 3- phase transformer has been analysed. For the two variants of the windings, the calculation results have been compared with the measured ones. Magnetic flux density components were calculated in and out of the core. The flux distribution and short-circuit reactance have been verified experimentally and a good agreement has been obtained.
Luminescence of a self-trapped exciton in GeO2 crystal
1993
Abstract The self-trapped exciton (STE) is discovered in the GeO2 crystal. A PL band at 2.5 eV with a strong Stokes shift is excited only in the fundamental absorption range of GeO2 crystal with the quantum yield about 0.4 and the decay time constant 800 ± 5 μs at 80 K. The PL thermal quenching occurs at 200 K with the energy about 0.25 eV and the frequency factor 107. At 4.5 K the PL decay kinetics splits into two components with time constants 270 μs and 8000 μs, which can be due to a triplet state split in the zero magnetic field. The STE in GeO2 is very similar to a STE in SiO2.
EMI Analysis in Electrical Drives under Lightning Surge Conditions
2012
In this paper, a complete model of a power drive system including the earth electrodes is proposed to evaluate electromagnetic conducted interference due to lightning pulses. Circuit model of a power drive system is joined with a full-wave approach for the simulation of the time behavior of the grounding system. The proposed model enables to predict the electromagnetic conducted interference generated in the power drive system when lightning conditions involve the earth electrodes.
Raman investigation of single oxidized carbon nanotubes
2001
The oxidation process of single-walled carbon nanotubes via nitric acid treatment was followed by IR-, UV-Vis-NIR, and single bundle Raman spectroscopy. The introduction of functional, oxygen-containing groups is revealed by an additional absorption band at 1725 cm−1, characteristic of carbonyl stretch vibrations. No significant shift of the optical absorption bands could be detected after oxidation. The combination of atomic force microscopy and confocal scanning resonance-enhanced Raman microscopy was used to investigate thin bundles and, eventually, individual nanotubes in detail. These experiments enabled determination of the dependence of the Raman intensity of the G-line (around 1590 …
A General Mathematical Formulation for Winding Layout Arrangement of Electrical Machines
2018
Winding design methods have been a subject of research for many years of the past century. Many methods have been developed, each one characterized by some advantages and drawbacks. Nowadays, the star of slots is the most widespread design tool for electrical machine windings. In this context, this paper presents a simple and effective procedure to determine the distribution of the slot EMFs over the phases and of the winding configuration in all possible typologies of electrical machines equipped with symmetrical windings. The result of this procedure gives a Winding Distribution Table (WDT), which can be used to define coils and coil groups connections and also to simply implement winding…
A General Investigation on the Differential Leakage Factor for Symmetrical and Asymmetrical Multiphase Winding Design
2020
This work provides an investigation based on a fast estimation of the degree of unbalance (D.U.%) and the differential leakage factor (&sigma
Reliable Propagation of Magnetic Domain Walls in Cross Structures for Advanced Multiturn Sensors
2017
[EN] We develop and analyze an advanced concept for a domain-wall-based sensing of rotations. Moving domain walls in n closed loops with n - 1 intersecting convolutions by rotating fields, we are able to sense n rotations. By combining loops with coprime numbers of rotations, we create a sensor system allowing for the total counting of millions of turns of a rotating applied magnetic field. We analyze the operation of the sensor and identify the intersecting cross structures as the critical component for reliable operation. Specifically, depending on the orientation of the applied field angle with the magnetization in the branches of the cross, a domain wall is found to propagate in an unwa…