4,992 research outputs found
Impacts of risks perceptions on decision-making on mitigation of losses from natural hazards: case studies of the 1995 Kobe, the 2004 Sumatra-Andaman and the 2011 Tohoku earthquakes
Current multi-risk disasters, such as the 2011 Tohoku earthquake, tsunami and nuclear disaster and the 2004 Sumatra-Andaman earthquake and tsunami, showed the need of a multi-risk approach in hazards mitigation and management, which makes the decision-making process on assessment of probabilities and making choices for risks mitigation even more complex. This motivated us to focus on two research questions. The first one is if stakeholders treat such hazards separately from each other, neglecting interdependencies and frequent causal, spatial and temporal relationships between different kinds of risk. The second one is how their behavior is influenced by different kinds of behavioral biases, leading to false estimations of probabilities of multi-hazard events and further choices in the decision-making process in regards to the multi-risk mitigation and management. Our methodology to approach these questions included case study method to identify cognitive and behavioral biases in frames of historical multi-risk disasters and conceptual content analysis to understand, which from the identified biases were the most influential in the decision-making process. We first conducted stakeholder interview to identify cases of multi-risk decision-making, then we conducted content analysis and case studies to understand how various cognitive and behavioral biases hampered risk governance and management in the identified cases. Our results showed that availability heuristics, loss aversion and limited worry were three most common biases, at the same time as experimental versus statistical evidence and bounded rationality were playing the least significant role in the decision-making process
Specific Heat and Superfluid Density for Possible Two Different Superconducting States in NaxCoO2.yH2O
Several thermodynamic measurements for the cobaltate superconductor,
NaxCoO2.yH2O, have so far provided results inconsistent with each other. In
order to solve the discrepancies, we microscopically calculate the temperature
dependences of specific heat and superfluid density for this superconductor. We
show that two distinct specific-heat data from Oeschler et al. and Jin et al.
are reproduced, respectively, for the extended s-wave state and the p-wave
state. Two different superfluid-density data are also reproduced for each case.
These support our recent proposal of possible two different pairing states in
this material. In addition, we discuss the experimentally proposed large
residual Sommerfeld coefficient and extremely huge effective carrier mass.Comment: 5 pages, 4 figures, Submitted to J. Phys. Soc. Jp
[CII] emission and star formation in the spiral arms of M31
The CII 158 microns line is the most important coolant of the interstellar
medium in galaxies but substantial variations are seen from object to object.
The main source of the emission at a galactic scale is still poorly understood.
Previous studies of the CII emission in galaxies have a resolution of several
kpc or more so the observed emission is an average of different ISM components.
The aim of this work is to study, for the first time, the CII emission at the
scale of a spiral arm. We want to investigate the origin of this line and its
use as a tracer of star formation. We present CII and OI observations of a
segment of a spiral arm of M~31 using the Infrared Space Observatory. The CII
emission is compared with tracers of neutral gas (CO, HI) and star formation
(H\alpha, Spitzer 24 mu.) The similarity of the CII emission with the Ha and 24
mu images is striking when smoothed to the same resolution, whereas the
correlation with the neutral gas is much weaker. The CII cooling rate per H
atom increases dramatically from ~2.7e-26 ergs/s/atom in the border of the map
to ~ 1.4e-25 ergs/s/atom in the regions of star formation. The CII/FIR(42-122)
ratio is almost constant at 2%, a factor 3 higher than typically quoted.
However, we do not believe that M~31 is unusual. Rather, the whole-galaxy
fluxes used for the comparisons include the central regions where the CII/FIR
ratio is known to be lower and the resolved observations neither isolate a
spiral arm nor include data as far out in the galactic disk as the observations
presented here. A fit to published PDR models yields a plausible average
solution of G_0~100 and n~3000 for the PDR emission in the regions of star
formation in the arm of M31.Comment: 8 pages, 5 figures. To be published by A&A. Low quality figures. High
quality version in http://www.obs.u-bordeaux1.fr/Radio/NRodriguez/out/m31.pd
Dynamics of Multiferroic Domain Wall in Spin-Cycloidal Ferroelectric DyMnO
We report the dielectric dispersion of the giant magnetocapacitance (GMC) in
multiferroic DyMnO over a wide frequency range. The GMC is found to be
attributable not to the softened electromagnon but to the electric-field-driven
motion of multiferroic domain wall (DW). In contrast to conventional
ferroelectric DWs, the present multiferroic DW motion holds extremely high
relaxation rate of s even at low temperatures. This
mobile nature as well as the model simulation suggests that the multiferroic DW
is not atomically thin as in ferroelectrics but thick, reflecting its magnetic
origin.Comment: 4 pages, 4 figure
Sub-Cycle Optical Response Caused by Dressed State with Phase-Locked Wavefunctions
The coherent interaction of light with matter imprints the phase information
of the light field on the wavefunction of the photon-dressed electronic state.
Driving electric field, together with a stable phase that is associated with
the optical probe pulses, enables the role of the dressed state in the optical
response to be investigated. We observed optical absorption strengths modulated
on a sub-cycle timescale in a GaAs quantum well in the presence of a
multi-cycle terahertz driving pulse using a near-infrared probe pulse. The
measurements were in good agreement with the analytical formula that accounts
for the optical susceptibilities caused by the dressed state of excitons, which
indicates that the output probe intensity was coherently reshaped by the
excitonic sideband emissions
Diode-array coupled time-resolved transmission grating spectrometer
Copyright 1986 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 57(10), 2489-2492, 1986 and may be found at http://dx.doi.org/10.1063/1.113909
Magnon-photon coupling in the noncollinear magnetic insulator Cu 2 OSeO 3
Anticrossing behavior between magnons in the noncollinear chiral magnet Cu2OSeO3 and a two-mode X-band microwave resonator was studied in the temperature range 5–100 K. In the field-induced ferrimagnetic phase, we observed a strong-coupling regime between magnons and two microwave cavity modes with a cooperativity reaching 3600. In the conical phase, cavity modes are dispersively coupled to a fundamental helimagnon mode, and we demonstrate that the magnetic phase diagram of Cu2OSeO3 can be reconstructed from the measurements of the cavity resonance frequency. In the helical phase, a hybridized state of a higher-order helimagnon mode and a cavity mode—a helimagnon polariton—was found. Our results reveal a class of magnetic systems where strong coupling of microwave photons to nontrivial spin textures can be observed
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