The s-Process Nucleosynthesis in Extremely Metal-Poor Stars as the Generating Mechanism of Carbon Enhanced Metal-Poor Stars

The origin of carbon-enhanced metal-poor (CEMP) stars plays a key role in characterising the formation and evolution of the first stars and the Galaxy since the extremely-poor (EMP) stars with [Fe/H] \leq -2.5 share the common features of carbon enhancement in their surface chemical compositions. The origin of these stars is not yet established due to the controversy of the origin of CEMP stars without the enhancement of s-process element abundances, i.e., so called CEMP-no stars. In this paper, we elaborate the s-process nucleosynthesis in the EMP AGB stars and explore the origin of CEMP stars. We find that the efficiency of the s-process is controlled by O rather than Fe at [Fe/H] \lesssim -2. We demonstrate that the relative abundances of Sr, Ba, Pb to C are explained in terms of the wind accretion from AGB stars in binary systems.Comment: The Proceedings of the Nuclei in the Cosmos XIV, in pres

Measurement of Social Preference from Utility-Based Choice Experiments

Ever since the classical works of Smith and Veblen, economists have recognized that individuals care about their relative positions and status in addition to their own consumption. This paper addresses a new framework of choice experiments in order to specify the shape of utility function with preference externalities. Theoretical studies on social preference, which are conducted without estimating or calibrating important parameters of social preference and put forward various propositions in accordance with the parameters assumed, can refer to the parameters estimated in this paper. Our findings complement those of happiness studies which support the view of social preference. We show that preference externality is, on average, characterized by jealousy among Japanese respondents, and also that heterogeneity in social preference parameters is driven by differences in income levels, age, and gender.

Systematic Design of Antireflection Coating for Semi-infinite One-dimensional Photonic Crystals Using Bloch Wave Expansion

We present a systematic method for designing a perfect antireflection coating (ARC) for a semi-infinite one-dimensional (1D) photonic crystal (PC) with an arbitrary unit cell. We use Bloch wave expansion and time reversal symmetry, which leads exactly to analytic formulas of structural parameters for the ARC and renormalized Fresnel coefficients of the PC. Surface immittance (admittance and impedance) matching plays an essential role in designing the ARC of 1D PC's, which is shown together with a practical example.Comment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physic

A Numerical Study on Assessing Sustainable Development with Future Genuine Savings Simulation

This paper presents a numerical examination of sustainability from the perspective of "Genuine Savings," using a data set provided by the World Bank. Unlike previously-used criteria of sustainability that focuses on observed paths of genuine savings rates, we consider future sustainability by simulating future paths of genuine savings. This analysis shows that some countries that had been classified as being sustainable by previous studies, using observed paths, are, in fact, not sustainable from the perspective of future sustainability. We provide information on capital components which should be targeted by policymakers in order to maintain future sustainability.

The Stellar Abundances for Galactic Archeology (SAGA) Database - Compilation of the Characteristics of Known Extremely Metal-Poor Stars

We describe the construction of a database of extremely metal-poor (EMP) stars in the Galactic halo whose elemental abundances have been determined. Our database contains detailed elemental abundances, reported equivalent widths, atmospheric parameters, photometry, and binarity status, compiled from papers in the recent literature that report studies of EMP halo stars with [Fe/H] < -2.5. The compilation procedures for this database have been designed to assemble the data effectively from electronic tables available from online journals. We have also developed a data retrieval system that enables data searches by various criteria, and permits the user to explore relationships between the stored variables graphically. Currently, our sample includes 1212 unique stars (many of which are studied by more than one group) with more than 15000 individual reported elemental abundances, covering all of the relevant papers published by December 2007. We discuss the global characteristics of the present database, as revealed by the EMP stars observed to date. For stars with [Fe/H] < -2.5, the number of giants with reported abundances is larger than that of dwarfs by a factor of two. The fraction of carbon-rich stars (among the sample for which the carbon abundance is reported) amount to ~30 % for [Fe/H] < -2.5. We find that known binaries exhibit different distributions of orbital period, according to whether they are giants or dwarfs, and also as a function of metallicity, although the total sample of such stars is still quite small.Comment: 24 pages, 10 figures, accepted by PASJ, final version. The SAGA database is available at http://saga.sci.hokudai.ac.j

A Scientific and Economic View on Collaboration, Balancing vs. Sharing

There is a class of artifacts bodies and their science, also known as 3M & I-bodies in 2008, which consist of human, material/machine, monetary and informational components. For multi-body systems, the paper discusses and develops the scientific and economic fundamentals of the Follett-like classification as domination, compromise, integration and sharing in 2-center conflict types (Matsui, 1983). That is, the mathematical view is based on the Venn diagram of sets in mathematics, the physical view is based on the principle of the lever in Archimedes’ work, and the economical view is based on the profit (specific gravity) and Matsui’s equation. From a systematic view composed of these, it is obtained that the integration pursues the maximization of intersection (compromise) in the two-center, whereas the sharing pursues the minimization of intersection (compromise) in field. When the marginal (maximal) profit is the same, both are pointed out to be similar on the relation of classical Nash’s solution and duality; the scientific and economic findings will contribute to the advance of the coming society and its visibility and harmony in collaboration vs. sharing