Diurnal variations from muon data at Takeyama underground station

An underground station, Takeyama, is introduced, and some results of the solar diurnal and semi-diurnal variations for the period between 1967 and 1984 are presented. There are clear tendencies of double and single solar cycle variations in the daily variations which are in good accord with those detected by other underground and neutron monitor observations

Contingent Capital and Bank Risk-Taking among British Banks before World War I

The recent financial turmoil highlights the incentive of highly leveraged financial institutions to take excessive risk, given the protection of limited liability. During the nineteenth and early twentieth century, many banks operated under liability rules which obligated shareholders to bear larger costs of bank insolvency in the form of contingent, or even unlimited liability. This paper examines the empirical relationship between the size of banks’ contingent liability and their risk-taking behavior using data on British banks from 1878-1912. We find that banks with more contingent liability appear to have taken less risk. We also find evidence that the risk-reducing effects of contingent liability were larger for banks with higher leverage, suggesting that contingent capital mitigated moral hazard problem at banks.Contingent Capital, Bank Risk-Taking, British Banks

JVN observations of H2O masers around the evolved star IRAS 22480+6002

We report on the H2O maser distributions around IRAS 22480+6002 (=IRC+60370) observed with the Japanese VLBI Network (JVN) at three epochs spanning 2 months. This object was identified as a K-type supergiant in 1970s, which was unusual as a stellar maser source. The spectrum of H2O masers consists of 5 peaks separated roughly equally by a few km/s each. The H2O masers were spatially resolved into more than 15 features, which spread about 50 mas along the east--west direction. However, no correlation was found between the proper motion vectors and their spatial distributions; the velocity field of the envelope seems random. A statistical parallax method applied to the observed proper-motion data set gives a distance of 1.0+-0.4 kpc for this object, that is considerably smaller than previously thought. The distance indicates that this is an evolved star with L~5800 Lsun. This star shows radio, infrared, and optical characteristics quite similar to those of the population II post-AGB stars such as RV Tau variables.Comment: 7 pages, 5 figures, PASJ 60, No. 1 (2008 Feb. 25 issue) in press. High res. figures available at ftp://ftp.nro.nao.ac.jp/nroreport/no657.pdf.g

Fundamental study on a thin-film ae sensor for measurement of behavior of a multi-pad contact slider

To study the fundamental dynamic characteristics of a multi-pad slider for contact recording, we developed a thin-film piezoelectric acoustic emission array sensor on an Si-suspension with an array pattern similar to that of contact pads. Experiments showed that the sensitivity of the sensor is about 0. 11 V/N (slider thickness: 0.2 mm) and that each array sensor designed here is not influenced by the acoustic waves which occur due to contact with other contact pads, so the contact or non-contact condition of each pad can be measured

Superconductivity in Pseudo-Binary Silicide SrNixSi2-x with AlB2-Type Structure

We demonstrate the emergence of superconductivity in pseudo-binary silicide SrNixSi2-x. The compound exhibits a structural phase transition from the cubic SrSi2-type structure (P4132) to the hexagonal AlB2-type structure (P6/mmm) upon substituting Ni for Si at approximately x = 0.1. The hexagonal structure is stabilized in the range of 0.1 < x < 0.7. The superconducting phase appears in the vicinity of the structural phase boundary. Ni acts as a nonmagnetic dopant, as confirmed by the Pauli paramagnetic behavior.Comment: 12 pages, 5 figure

Piezoelectric impact force sensor array for tribological research on rigid disk storage media

This paper presents a method to measure impact forces on a surface by means of a piezoelectric thin film sensor array. The output signals of the sensor array provide information about the position, magnitude and wave form of the impact force. The sensor array may be used for tribological studies to the slider disk interface of a rigid disk storage device. In such a device a slider head assembly is flying above the rotating disk with a typical spacing of 100nm. Possible mechanical interactions between the slider and the disk are expected to produce impact forces in the order of 0.1N with a frequency range from 100kHz to 100MHz [1]

Thin-film piezoelectric impact sensor array fabricated on a Si slider for measuring head-disk interaction

A new type of Acoustic Emission sensor using a thin film piezoelectric material (sputtered ZnO) was developed for measuring head-disk interaction in a rigid magnetic disk system. The sensor is mounted on a Si slider (length: 3 mm) and was fabricated using micro-machining techniques in our on-going efforts to downsize sliders. Some fundamental tests of the sensor were conducted: sensitivity and frequency characteristics, and a flying test over a rotating bump disk

κ\kappa-Deformed Statistics and Classical Fourmomentum Addition Law

We consider $\kappa$-deformed relativistic symmetries described algebraically by modified Majid-Ruegg bicrossproduct basis and investigate the quantization of field oscillators for the $\kappa$-deformed free scalar fields on $\kappa$-Minkowski space. By modification of standard multiplication rule, we postulate the $\kappa$-deformed algebra of bosonic creation and annihilation operators. Our algebra permits to define the n-particle states with classical addition law for the fourmomenta in a way which is not in contradiction with the nonsymmetric quantum fourmomentum coproduct. We introduce $\kappa$-deformed Fock space generated by our $\kappa$-deformed oscillators which satisfy the standard algebraic relations with modified $\kappa$-multiplication rule. We show that such a $\kappa$-deformed bosonic Fock space is endowed with the conventional bosonic symmetry properties. Finally we discuss the role of $\kappa$-deformed algebra of oscillators in field-theoretic noncommutative framework.Comment: LaTeX, 12 pages. V2: second part of chapter 4 changed, new references and comments added. V3: formula (14) corrected. Some additional explanations added. V4: further comments about algebraic structure are adde