158 research outputs found

    Economy-wide impacts of consumer responses to environmental information disclosure in Tokyo and the other parts of Japan

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    Environmental problems such as global warming due to GHG emissions have necessitated some constraint in our economic activities, as many countries and many people around the world are concerned about these issues. Environmental and economic policies such as carbon tax are one such constraint. A tax policy can be interpreted as a desirable method that can lead the economy, which has to pay the social cost of false economic activity or market failure, to a more optimal path. However, this policy will surely raise prices of goods. On the one hand, this price rise will benefit the public sector, but on the other hand, consumers demand will decline. The magnitude of the reduction usually depends on the price elasticity of demand, and the increase in government gain depends on the necessity of the goods for the people. Therefore, it is not necessarily trivial to ask whether the total effect of rising energy prices will be negative. In addition, nowadays, many people are concerned about environmental problems, and there are indications that consumers tend to change their purchasing behavior regarding certain goods to take environmental concerns into account even if this necessitates paying a higher price. This paper will empirically prove how the rise in oil and gas prices due to environmental policies like carbon tax affects the total production/consumption when we take into account the change in consumer behavior reflecting their attitudes toward preventing global warming. The main result of the analysis using an input-output model and price elasticity of demand in several sectors will show that most of sectors do not experience a decline in production after a price rise except the biggest sector, real estate. In Japan, real estate might be the main target to support for consumerfs purchasing from the viewpoint of economic policy.consumer behavior; disclosure of information about environmental damage; energy price rising effect; price elasticity of demand; International Input-Output model.

    The bar-mode instability in differentially rotating neutron stars: Simulations in full general relativity

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    We study the dynamical stability against bar-mode deformation of rapidly spinning neutron stars with differential rotation. We perform fully relativistic 3D simulations of compact stars with M/R0.1M/R \geq 0.1, where MM is the total gravitational mass and RR the equatorial circumferential radius. We adopt an adiabatic equation of state with adiabatic index Γ=2\Gamma=2. As in Newtonian theory, we find that stars above a critical value of βT/W\beta \equiv T/W (where TT is the rotational kinetic energy and WW the gravitational binding energy) are dynamically unstable to bar formation. For our adopted choices of stellar compaction and rotation profile, the critical value of β=βdGR\beta = \beta_{dGR} is 0.240.25\sim 0.24-0.25, only slightly smaller than the well-known Newtonian value 0.27\sim 0.27 for incompressible Maclaurin spheroids. The critical value depends only very weakly on the degree of differential rotation for the moderate range we surveyed. All unstable stars form bars on a dynamical timescale. Models with sufficiently large β\beta subsequently form spiral arms and eject mass, driving the remnant to a dynamically stable state. Models with moderately large ββdGR\beta \gtrsim \beta_{dGR} do not develop spiral arms or eject mass but adjust to form dynamically stable ellipsoidal-like configurations. If the bar-mode instability is triggered in supernovae collapse or binary neutron star mergers, it could be a strong and observable source of gravitational waves. We determine characteristic wave amplitudes and frequencies.Comment: 17 pages, accepted for publication in AP

    Non-conformally flat initial data for binary compact objects

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    A new method is described for constructing initial data for a binary neutron-star (BNS) system in quasi-equilibrium circular orbit. Two formulations for non-conformally flat data, waveless (WL) and near-zone helically symmetric (NHS), are introduced; in each formulation, the Einstein-Euler system, written in 3+1 form on an asymptotically flat spacelike hypersurface, is exactly solved for all metric components, including the spatially non-conformally flat potentials, and for irrotational flow. A numerical method applicable to both formulations is explained with an emphasis on the imposition of a spatial gauge condition. Results are shown for solution sequences of irrotational BNS with matter approximated by parametrized equations of state that use a few segments of polytropic equations of state. The binding energy and total angular momentum of solution sequences computed within the conformally flat -- Isenberg-Wilson-Mathews (IWM) -- formulation are closer to those of the third post-Newtonian (3PN) two point particles up to the closest orbits, for the more compact stars, whereas sequences resulting from the WL/NHS formulations deviate from the 3PN curve even more for the sequences with larger compactness. We think it likely that this correction reflects an overestimation in the IWM formulation as well as in the 3PN formula, by 1\sim 1 cycle in the gravitational wave phase during the last several orbits. The work suggests that imposing spatial conformal flatness results in an underestimate of the quadrupole deformation of the components of binary neutron-star systems in the last few orbits prior to merger.Comment: 22 pages, 7 figure

    On the Maximum Mass of Differentially Rotating Neutron Stars

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    We construct relativistic equilibrium models of differentially rotating neutron stars and show that they can support significantly more mass than their nonrotating or uniformly rotating counterparts. We dynamically evolve such ``hypermassive'' models in full general relativity and show that there do exist configurations which are dynamically stable against radial collapse and bar formation. Our results suggest that the remnant of binary neutron star coalescence may be temporarily stabilized by differential rotation, leading to delayed collapse and a delayed gravitational wave burst.Comment: 4 pages, 2 figures, uses emulateapj.sty; to appear in ApJ Letter

    Innermost stable circular orbits around relativistic rotating stars

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    We investigate the innermost stable circular orbit (ISCO) of a test particle moving on the equatorial plane around rotating relativistic stars such as neutron stars. First, we derive approximate analytic formulas for the angular velocity and circumferential radius at the ISCO making use of an approximate relativistic solution which is characterized by arbitrary mass, spin, mass quadrupole, current octapole and mass 242^4-pole moments. Then, we show that the analytic formulas are accurate enough by comparing them with numerical results, which are obtained by analyzing the vacuum exterior around numerically computed geometries for rotating stars of polytropic equation of state. We demonstrate that contribution of mass quadrupole moment for determining the angular velocity and, in particular, the circumferential radius at the ISCO around a rapidly rotating star is as important as that of spin.Comment: 12 pages, 2 figures, accepted for publication in Phys. Rev.

    Magnetorotational collapse of massive stellar cores to neutron stars: Simulations in full general relativity

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    We study magnetohydrodynamic (MHD) effects arising in the collapse of magnetized, rotating, massive stellar cores to proto-neutron stars (PNSs). We perform axisymmetric numerical simulations in full general relativity with a hybrid equation of state. The formation and early evolution of a PNS are followed with a grid of 2500 x 2500 zones, which provides better resolution than in previous (Newtonian) studies. We confirm that significant differential rotation results even when the rotation of the progenitor is initially uniform. Consequently, the magnetic field is amplified both by magnetic winding and the magnetorotational instability (MRI). Even if the magnetic energy E_EM is much smaller than the rotational kinetic energy T_rot at the time of PNS formation, the ratio E_EM/T_rot increases to 0.1-0.2 by the magnetic winding. Following PNS formation, MHD outflows lead to losses of rest mass, energy, and angular momentum from the system. The earliest outflow is produced primarily by the increasing magnetic stress caused by magnetic winding. The MRI amplifies the poloidal field and increases the magnetic stress, causing further angular momentum transport and helping to drive the outflow. After the magnetic field saturates, a nearly stationary, collimated magnetic field forms near the rotation axis and a Blandford-Payne type outflow develops along the field lines. These outflows remove angular momentum from the PNS at a rate given by \dot{J} \sim \eta E_EM C_B, where \eta is a constant of order 0.1 and C_B is a typical ratio of poloidal to toroidal field strength. As a result, the rotation period quickly increases for a strongly magnetized PNS until the degree of differential rotation decreases. Our simulations suggest that rapidly rotating, magnetized PNSs may not give rise to rapidly rotating neutron stars.Comment: 28 pages, 20 figures, accepted for publication in Phys. Rev.

    Identification and characterization of neural crest-derived cells in adult periodontal ligament of mice

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    Cells derived from the neural crest (NC) contribute to the development of several adult tissues, including tooth and periodontal tissue. Here, two transgenic lines, Wnt1-Cre/ZEG and P0-Cre/ZEGwere analyzed to determine the fate and distribution of neural crest cells (NCCs) in adult mouse periodontal ligament (PDL)
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