20,666 research outputs found
Approach Toward a Unified Health Insurance System: What Can Japan Learn from the Korean Experience.
We discuss that Japan should make a comprehensive reform of the existing institutions of health insurance in view of the apparent structural problems centering on the financial instability of health care finance, and discrepancies in premiums and benefits among the insured.HEALTH ; JAPAN ; KOREA
Aqueous Phase C-H Bond Oxidation Reaction of Arylalkanes Catalyzed by a Water-Soluble Cationic Ru(III) Complex [(pymox-Me\u3csub\u3e2\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3eRuCl\u3csub\u3e2\u3c/sub\u3e]\u3csup\u3e+\u3c/sup\u3eBF\u3csub\u3e4\u3c/sub\u3e\u3csup\u3e-\u3c/sup\u3e
The cationic complex [(pymox-Me2)RuCl2]+BF4− was found to be a highly effective catalyst for the C−H bond oxidation reaction of arylalkanes in water. For example, the treatment of ethylbenzene (1.0 mmol) with t-BuOOH (3.0 mmol) and 1.0 mol % of the Ru catalyst in water (3 mL) cleanly produced PhCOCH3 at room temperature. Both a large kinetic isotope effect (kH/kD = 14) and a relatively large Hammett value (ρ = −1.1) suggest a solvent-caged oxygen rebounding mechanism via a Ru(IV)-oxo intermediate species
Orientational Melting in Carbon Nanotube Ropes
Using Monte Carlo simulations, we investigate the possibility of an
orientational melting transition within a "rope" of (10,10) carbon nanotubes.
When twisting nanotubes bundle up during the synthesis, orientational
dislocations or twistons arise from the competition between the anisotropic
inter-tube interactions, which tend to align neighboring tubes, and the torsion
rigidity that tends to keep individual tubes straight. We map the energetics of
a rope containing twistons onto a lattice gas model and find that the onset of
a free "diffusion" of twistons, corresponding to orientational melting, occurs
at T_OM > 160 K.Comment: 4 page LaTeX file with 3 figures (10 PostScript files
Anomalous kinetics of attractive reactions
We investigate the kinetics of reaction with the local attractive
interaction between opposite species in one spatial dimension. The attractive
interaction leads to isotropic diffusions inside segregated single species
domains, and accelerates the reactions of opposite species at the domain
boundaries. At equal initial densities of and , we analytically and
numerically show that the density of particles (), the size of domains
(), the distance between the closest neighbor of same species
(), and the distance between adjacent opposite species ()
scale in time as , , and respectively. These dynamical exponents form a new
universality class distinguished from the class of uniformly driven systems of
hard-core particles.Comment: 4 pages, 4 figure
Investigation of the Influence of the Clay Seams Around an Underground Excavation in Rock Salt
The presence of clay seams in the roof is especially important for assessing the stability of the excavations in salt and potash mines, since they allow separation as well as horizontal slip. The deformational behavior at clay seams in the roof of excavations was investigated by using actual field measurements made at the Waste Isolation Pilot Plant (WlPP) site. From the in situ deformation measurements, the separation and separation rate across the clay seams in the roof and floor could be estimated by using the technique developed in this study. The horizontal displacement along the clay seams was determined from the deflection measurements and compared with the predictions from a computer simulation using FLAC and clastic beam theory
Charge and Orbital Ordering and Spin State Transition Driven by Structural Distortion in YBaCo_2O_5
We have investigated electronic structures of antiferromagnetic YBaCo_2O_5
using the local spin-density approximation (LSDA) + U method. The charge and
orbital ordered insulating ground state is correctly obtained with the strong
on-site Coulomb interaction. Co^{2+} and Co^{3+} ions are found to be in the
high spin (HS) and intermediate spin (IS) state, respectively. It is considered
that the tetragonal to orthorhombic structural transition is responsible for
the ordering phenomena and the spin states of Co ions. The large contribution
of the orbital moment to the total magnetic moment indicates that the
spin-orbit coupling is also important in YBaCo_2O_5.Comment: 4 pages including 4 figures, Submitted to Phys. Rev. Let
Event-triggered proportional-derivative control for nonlinear network systems with a novel event-triggering scheme: Differential of triggered state consideration
This article proposes event-triggered proportional-derivative control for a class of nonlinear network control systems. For derivative action of the proposed proportional-derivative control, a novel event-triggering scheme is devised together with the control that considers a differential of a triggered state. The class of the nonlinear network systems is represented as a Lur'e system to consider various nonlinear cases. Time varying transmission delay is considered which can be defined by lower and upper delay bounds. The proposed proportional-derivative control is designed by Lyapunov-Krasovskii stability analysis, and the design condition is presented by linear matrix inequalities. The proposed event-triggered proportional-derivative control and event-triggering condition are verified with numerical simulation. ? 2017 The Author(s).111Ysciescopu
Nonlinear Response of Cylindrical Shells to Underwater Explosion: Testings and Numerical Prediction Using USA/DYNA3D / June 1, 1991 - March 1, 1992
The views expressed are those of the authors and do not reflect the offical policy or position of DoD or US Government.Nonlinear 3-D Dynamic Analysis Code (VEC/DYNA3D) has been interfaced with Underwater Shock Analysis Code (USA) and capabilities were developed to perform numerical analysis of submerged and semi-submerged marine structures subjected to underwater explosion. A series of numerical analysis were performed to determine the elastic and elasto-plastic responses of cylindrica shell type structures. The results were favorably compared with those of underwater explosion testings. The coupled code USA/DYNA3D makes possible to predict shock-induced damage response of naval structure. In addition, numerical sensitivity analyses were undertaken to determine the importance of various physical and numerical modeling factors. This study showed clearly three types of response modes of cylinder subjected to a side-on explosion: accordion mode, breathing mode and whipping mode.This report was prepared for and funded by both Defense Nuclear Agency,
Alexandria, VA 20311 and Naval Postgraduate School, Monterey, CA 93943.Approved for public release; distribution is unlimited
Response of dual-layered structures subjected to shock pressure wave
The response of coated, metallic structures subjected to shock pressure waves is studied. The coating is either an elastic material or nearly incompressible rubber of variable stiffness separating the structure from an air or water medium. The stress, nodal velocity, and internal energy of the coated structure are compared to a system without a coating (homogeneous system) to examine the effect of various coating types and configurations on the response of the structure to shock conditions. The results show that a mismatch of impedance, pc0, between the coating and structure governs the degree of energy exchange between the coating and structure at the interface. The impedance mismatch between the structure and a rubber coating at the threshold value is termed the critical difference. If the impedance mismatch exceeds the critical difference, the dynamic response will be more adverse. A softer coating generally has a smaller impedance and tends to concentrate stress wave energy in the underlying structureDefense Nuclear Agency, Alexandria, VAhttp://archive.org/details/responseofdualla00brasMIPR No. 94-573N
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