Progress in development of silica aerogel for particle- and nuclear-physics experiments at J-PARC

This study presents the advancement in hydrophobic silica aerogel development for use as Cherenkov radiators and muonium production targets. These devices are scheduled for use in several particle- and nuclear-physics experiments that are planned in the near future at the Japan Proton Accelerator Research Complex. Our conventional method to produce aerogel tiles with an intermediate index of refraction of approximately 1.05 is extended so that we can now produce aerogel tiles with lower indices of refraction (i.e., 1.03-1.04) and higher indices of refraction (i.e., 1.075-1.08); each with excellent transparency. A new production method, called pin drying, was optimized to produce larger area aerogels consistently with an ultrahigh index of refraction (>1.10). In addition, for use as a thermal-muonium-emitting material at room temperature, dedicated low-density aerogels were fabricated using the conventional method.Comment: To be published in JPS Conf. Proc., 6 pages, 3 figure

Organizational Modes within Firms and Productivity Growth

This paper develops a simple growth model with moral hazard contracting to examine the interactions between the organizational mode of firms and economic productivity growth. The organizational mode of firms differs in terms of the degree to which decisions of R&D investment are delegated to a manager. We show that the market size restricts the extent of delegation with respect to R&D, which in turn determines the productivity growth rate of the economy. We then show that there exist multiple equilibria: gpartial decentralization equilibriumh with a low growth rate and gfull decentralization equilibriumh with a high growth rate. Finally, we study the effects of social capital and competition on equilibrium organizational modes and show that, under some parametric conditions, these factors induce more decentralized organization and higher productivity growth while lowering the risk of the economy converging to a poverty trap.Centralization and Decentralization, Moral Hazard, Social Capital, Multiple Equilibria, Economic Growth, Competitive Policy

The Sensitivity Analysis of the Optimal Length of Life -the Numerical Approach-.

This paper solves the pure consumption Grossman model numerically following dynamic programming method, and undertakes sensitivity analysis of the optimal length of life. This is the first analysis that treats the determination of optimal length of life explicitly with numerical analysis.MATHEMATICS ; LIFE

Error estimates of a stabilized Lagrange-Galerkin scheme for the Navier-Stokes equations

Error estimates with optimal convergence orders are proved for a stabilized Lagrange-Galerkin scheme for the Navier-Stokes equations. The scheme is a combination of Lagrange-Galerkin method and Brezzi-Pitkaranta's stabilization method. It maintains the advantages of both methods; (i) It is robust for convection-dominated problems and the system of linear equations to be solved is symmetric. (ii) Since the P1 finite element is employed for both velocity and pressure, the number of degrees of freedom is much smaller than that of other typical elements for the equations, e.g., P2/P1. Therefore, the scheme is efficient especially for three-dimensional problems. The theoretical convergence orders are recognized numerically by two- and three-dimensional computations

Is the innate bio-protection power against human virus the same between males and females? A conclusion based on blood donor data of HTLV-I infection

Human T-cell leukemia virus type I (HTLV-I) is a retrovirus that causes adult T-cell leukemia. The male-to-female transmission is stronger than the reverse, so the carrier proportion of women is greater than that of men. On the other hand, since the mother-to-child transmission route via the breast-feeding is common for baby boys and girls, it has been thought the HTLV-I proportions of boys and girls are the same until now. A question arises as to whether the "innate protection powers against human virus" are the same between baby boys and girls. We utilize Blood donors in 1995-1998, which were provided by Japan Red Cross Society of Oita, Japan. The data are summarized into the frequency table with respect to gender and age. The age groups are <20, 20<age≤30, 30<age≤40, 40<age≤50, and >50 years old. The comparison of carrier proportions of males and females under 20 years old is made with a two-sided statistical test and for the other groups one-sided tests are carried out. The preset statistical analysis shows that the carrier proportion of girls is less than that that of boys. It implies that in HTLV-I the mother-to-child transmission probability of females is less than that of males. According to the present findings, it follows that the female's innate protection power against HTLV-I is stronger than that of males, and the conclusion may become a valid proposition for general human virus

Numerical analysis of the Oseen-type Peterlin viscoelastic model by the stabilized Lagrange-Galerkin method, Part I: A nonlinear scheme

We present a nonlinear stabilized Lagrange-Galerkin scheme for the Oseen-type Peterlin viscoelastic model. Our scheme is a combination of the method of characteristics and Brezzi-Pitk\"aranta's stabilization method for the conforming linear elements, which yields an efficient computation with a small number of degrees of freedom. We prove error estimates with the optimal convergence order without any relation between the time increment and the mesh size. The result is valid for both the diffusive and non-diffusive models for the conformation tensor in two space dimensions. We introduce an additional term that yields a suitable structural property and allows us to obtain required energy estimate. The theoretical convergence orders are confirmed by numerical experiments. In a forthcoming paper, Part II, a linear scheme is proposed and the corresponding error estimates are proved in two and three space dimensions for the diffusive model.Comment: See arXiv:1603.01074 for Part II: a linear schem