1,235 research outputs found
Orbital-Order Driven Ferroelectricity and Dipolar Relaxation Dynamics in Multiferroic GaMoS
We present the results of broadband dielectric spectroscopy of GaMoS,
a lacunar spinel system that recently was shown to exhibit non-canonical,
orbitally-driven ferroelectricity. Our study reveals complex relaxation
dynamics of this multiferroic material, both above and below its Jahn-Teller
transition at T K. Above T, two types of
coupled dipolar-orbital dynamics seem to compete: relaxations within
cluster-like regions with short-range polar order like in relaxor
ferroelectrics and critical fluctuations of only weakly interacting dipoles,
the latter resembling the typical dynamics of order-disorder type
ferroelectrics. Below the Jahn-Teller transition, the onset of orbital order
drives the system into long-range ferroelectric order and dipolar dynamics
within the ferroelectric domains is observed. The coupled dipolar and orbital
relaxation behavior of GaMoS above the Jahn-Teller transition markedly
differs from that of the skyrmion host GaVS, which seems to be linked
to differences in the structural distortions of the two systems on the
unit-cell level.Comment: 6 pages, 3 figures + Supplemental Material (2 pages, 2 figures
New Power Module Integrating Output Current Measurement Function
This paper proposes a new power module concept that integrates output current measurement function to make inverters compact. The current measurement function is realized by tiny printed-circuit-board (PCB) Rogowski coils. The PCB Rogowski coil picks up a switching current flowing through an IGBT chip, and then a combination of a digital circuit based on a field-programmable-gate-array (FPGA) and an integrator circuit reproduces the output current of the inverter from the switching current. A major concern of the new power module is the effect of reverse recovery current of free-wheeling diodes because the reverse recovery current is superimposed on the switching current. This paper proposes a mitigating method of the reverse recovery current.2017 29th International Symposium on Power Semiconductor Devices and IC\u27s (ISPSD), May 28 2017-June 1 2017, Sapporo, Japa
Tests of a proximity focusing RICH with aerogel as radiator
Using aerogel as radiator and multianode PMTs for photon detection, a
proximity focusing Cherenkov ring imaging detector has been constructed and
tested in the KEK 2 beam. The aim is to experimentally study the basic
parameters such as resolution of the single photon Cherenkov angle and number
of detected photons per ring. The resolution obtained is well approximated by
estimates of contributions from pixel size and emission point uncertainty. The
number of detected photons per Cherenkov ring is in good agreement with
estimates based on aerogel and detector characteristics. The values obtained
turn out to be rather low, mainly due to Rayleigh scattering and to the
relatively large dead space between the photocathodes. A light collection
system or a higher fraction of the photomultiplier active area, together with
better quality aerogels are expected to improve the situation. The reduction of
Cherenkov yield, for charged particle impact in the vicinity of the aerogel
tile side wall, has also been measured.Comment: 4 pages, 8 figure
Development of Auto Scaling Method for 3D Rock Fragmentation Measurement System
Fragmentation Distribution is one of the important aspects of mining operations as it affects productivities on the majority of Mine-to-Mill operations. Nevertheless the significance of fragmentation management, the mining industry has relied on 2D image based fragmentation measurement system which poses many downsides. To overcome the drawbacks of current 2D fragmentation measurement system, 3D Rock Fragmentation Measurement System has been proposed with using 3D photogrammetry technologies. One of the common difficulty of fragmentation measurement system is scaling of the object, which is an essential component to secure the accuracy of particle size distribution. In this study, the actual scales and size information of objects have been obtained by measuring the acceleration when moving between the photographing points and giving the information of the distance obtained from the acceleration. The developed system would be equipped with the 3D Rock Fragmentation Measurement System
Structural Survey and Artificial Induction of Aloeswood
この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました
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