Instrumental Resolution of the Chopper Spectrometer 4SEASONS Evaluated by Monte Carlo Simulation

We performed simulations of the resolution function of the 4SEASONS spectrometer at J-PARC by using the Monte Carlo simulation package McStas. The simulations showed reasonably good agreement with analytical calculations of energy and momentum resolutions by using a simplified description. We implemented new functionalities in Utsusemi, the standard data analysis tool used in 4SEASONS, to enable visualization of the simulated resolution function and predict its shape for specific experimental configurations.Comment: 8 pages, 5 figure

E-Defense Shaking Table Test on the Behavior of Liquefaction-Induced Lateral Spreading of Large-Scale Model Ground with a Pile-Foundation Structure Behind Quay Wall

To investigate the behavior of liquefaction-induced lateral spreading of ground and mechanism of its influencing failure of structures, a shaking table test of a large-scale model with liquefiable sand deposit was performed at the E-Defense shaking table testing facility. The model in a rigid container 16 meters long, 4 meters wide and 5 meters high had a pile-foundation structure behind caisson-type quay wall in the deposit. About 900 sensors and other instrumentations were installed with the model, acquiring accelerations, strains, pore water pressures, and even large displacements occurred by extensive behavior. To the model, two-dimensional, horizontal and vertical motions based on the records obtained in the 1995 Hyogoken-Nambu earthquake were applied, generating liquefaction of the deposit and following lateral spreading. The motions also made the caisson overturn to the waterside, resulting in large deformation of its backfill. Such behaviors caused three waterside piles to bend at the same level of the caisson’s mound. The testing result explained the influences of inertial force and ground deformation on the overturn of the caisson and the collapse of the structure. This observation is valuable regarding understanding of this phenomenon because there has been no such data resulting from observation during earthquakes until now

Probing the Structure of Gamma-Ray Burst Jets with Steep Decay Phase of their Early X-ray Afterglows

We show that the jet structure of gamma-ray bursts (GRBs) can be investigated with the tail emission of the prompt GRB. The tail emission which we consider is identified as a steep-decay component of the early X-ray afterglow observed by the X-ray Telescope onboard Swift. Using a Monte Carlo method, we derive, for the first time, the distribution of the decay index of the GRB tail emission for various jet models. The new definitions of the zero of time and the time interval of a fitting region are proposed. These definitions for fitting the light curve lead us an unique definition of the decay index, which is useful to investigate the structure of the GRB jet. We find that if the GRB jet has a core-envelope structure, the predicted distribution of the decay index of the tail has a wide scatter and has multiple peaks, which cannot be seen for the case of the uniform and the Gaussian jet. Therefore, the decay index distribution tells us the information on the jet structure. Especially, if we observe events whose decay index is less than about 2, both the uniform and the Gaussian jet models will be disfavored according to our simulation study.Comment: 21 pages, 10 figures, the paper with full resolution images is http://theo.phys.sci.hiroshima-u.ac.jp/~takami/research/achievements/papers/003_full.pd

Model Building of Metal Oxide Surfaces and Vibronic Coupling Density as a Reactivity Index: Regioselectivity of CO2_2 Adsorption on Ag-loaded Ga2_2O3_3

The step-by-step hydrogen-terminated (SSHT) model is proposed as a model for the surfaces of metal oxides. Using this model, it is found that the vibronic coupling density (VCD) can be employed as a reactivity index for surface reactions. As an example, the regioselectivity of CO$_2$ adsorption on the Ag-loaded Ga$_2$O$_3$ photocatalyst surface is investigated based on VCD analysis. The cluster model constructed by the SSHT approach reasonably reflects the electronic structures of the Ga$_2$O$_3$ surface. The geometry of CO$_2$ adsorbed on the Ag-loaded Ga$_2$O$_3$ cluster has a bent structure, which is favorable for its photocatalytic reduction to CO.Comment: 18 pages, 11 figure

Analyzing the impact of labor market integration

We develop a competitive search model involving multiple regions, geographically mobile workers, and moving costs. Equilibrium mobility patterns are analyzed and characterized, indicating that shocks to a particular region, such as a productivity shock, can propagate to other regions through workers' mobility. Moreover, equilibrium mobility patterns are not efficient due to the existence of moving costs, implying that they affect social welfare not only because they are costs but also because they distort equilibrium allocation. By calibrating our framework to Japanese regional data, we demonstrate that the impacts of eliminating migration costs are comparable to those of a 30% productivity increase

A modified repulsive bridge correction to accurate evaluation of solvation free energy in integral equation theory for molecular liquids

Integral equation theory for molecular liquids is one of the powerful frameworks to evaluate solvation free energy (SFE). Different from molecular simulation methods, the theory computes SFE in an analytical manner. In particular, the correction method proposed by Kovalenko and Hirata [Chem. Phys. Lett.290, 237 (Year: 1998);Kovalenko and Hirata J. Chem. Phys.113, 2793 (Year: 2000)]10.1063/1.1305885 is quite efficient in the accurate evaluation of SFE. However, the application has been limited to aqueous solution systems. In the present study, an improved method is proposed that is applicable to a wide range of solution systems. The SFE of a variety of solute molecules in chloroform and benzene solvents is evaluated. A key is the adequate treatment of excluded volume in SFE calculation. By utilizing the information of chemical bonds in the solvent molecule, the accurate computation of SFE is achieved