16,054 research outputs found
Assessing Ageing Condition of Mineral Oil-Paper Insulation by Polarization/Depolarization Current
Accurately assessing the ageing status of oil-paper insulation in transformer is essential and important. Polarization and Depolarization Current (PDC) technique is effective in assessing the condition of oil-paper insulation system. Though the PDC behaviour of mineral oil-paper insulation has been widely investigated, there is no report about how to make the quantitative analysis of mineral oil-paper insulation ageing condition by PDC. The PDC characteristics of mineral oil-paper insulation samples were investigated over the ageing period at 110°C. A new method for assessing the ageing condition of mineral oil-paper insulation by calculating the depolarization charge quantity was proposed. Results show that the depolarization charge quantity of mineral oil-paper insulation sample is very sensitive to its ageing condition. The stable depolarization charge quantity could be used to predict the ageing condition of mineral oil-paper insulation
Localized Control of Curie Temperature in Perovskite Oxide Film by Capping-layer- induced Octahedral Distortion
With reduced dimensionality, it is often easier to modify the properties of
ultra-thin films than their bulk counterparts. Strain engineering, usually
achieved by choosing appropriate substrates, has been proven effective in
controlling the properties of perovskite oxide films. An emerging alternative
route for developing new multifunctional perovskite is by modification of the
oxygen octahedral structure. Here we report the control of structural oxygen
octahedral rotation in ultra-thin perovskite SrRuO3 films by the deposition of
a SrTiO3 capping layer, which can be lithographically patterned to achieve
local control. Using a scanning Sagnac magnetic microscope, we show increase in
the Curie temperature of SrRuO3 due to the suppression octahedral rotations
revealed by the synchrotron x-ray diffraction. This capping-layer-based
technique may open new possibilities for developing functional oxide materials.Comment: Main-text 5 pages, SI 6 pages. To appear in Physical Review Letter
Recommended from our members
The cumulative effects of known susceptibility variants to predict primary biliary cirrhosis risk.
Multiple genetic variants influence the risk for development of primary biliary cirrhosis (PBC). To explore the cumulative effects of known susceptibility loci on risk, we utilized a weighted genetic risk score (wGRS) to evaluate whether genetic information can predict susceptibility. The wGRS was created using 26 known susceptibility loci and investigated in 1840 UK PBC and 5164 controls. Our data indicate that the wGRS was significantly different between PBC and controls (P=1.61E-142). Moreover, we assessed predictive performance of wGRS on disease status by calculating the area under the receiver operator characteristic curve. The area under curve for the purely genetic model was 0.72 and for gender plus genetic model was 0.82, with confidence limits substantially above random predictions. The risk of PBC using logistic regression was estimated after dividing individuals into quartiles. Individuals in the highest disclosed risk group demonstrated a substantially increased risk for PBC compared with the lowest risk group (odds ratio: 9.3, P=1.91E-084). Finally, we validated our findings in an analysis of an Italian PBC cohort. Our data suggested that the wGRS, utilizing genetic variants, was significantly associated with increased risk for PBC with consistent discriminant ability. Our study is a first step toward risk prediction for PBC
QCDOC: A 10-teraflops scale computer for lattice QCD
The architecture of a new class of computers, optimized for lattice QCD
calculations, is described. An individual node is based on a single integrated
circuit containing a PowerPC 32-bit integer processor with a 1 Gflops 64-bit
IEEE floating point unit, 4 Mbyte of memory, 8 Gbit/sec nearest-neighbor
communications and additional control and diagnostic circuitry. The machine's
name, QCDOC, derives from ``QCD On a Chip''.Comment: Lattice 2000 (machines) 8 pages, 4 figure
High-Pressure torsion-Induced Grain Growth in Electrodeposited Nanocrystalline Ni
Deformation-induced grain growth has been reported in nanocrystalline (nc) materials under indentation and severe cyclic loading, but not under any other deformation mode. This raises an issue on critical conditions for grain growth in nc materials. This study investigates deformation-induced grain growth in electrodeposited nc Ni during high-pressure torsion (HPT). Our results indicate that high stress and severe plastic deformation are required for inducing grain growth, and the upper limit of grain size is determined by the deformation mode and parameters. Also, texture evolution suggests that grain-boundary-mediated mechanisms played a significant role in accommodating HPT strain
- …