Nuclear resonant scattering of synchrotron radiation by physisorbed Kr on TiO2_{2}(110) surfaces in multilayer and monolayer regimes

Physisorbed Kr layers on TiO$_{2}$(110) surfaces were investigated by means of nuclear resonant scattering (NRS) of synchrotron radiation at Kr thicknesses ranging from multilayer to monolayer. The NRS intensity was measured as a function of the Kr exposure, from which the NRS signal corresponding to monolayer was estimated as 0.23 cps. The time spectra measured at various thicknesses showed a monotonous decay without any quantum beat features. The recoiless fraction $f$ evaluated from the analysis of the time spectrum revealed a substantial reduction upon temperature rise from 19 to 25 K. As its origin, an order-disorder phase transition of the monolayer Kr is proposed.Comment: 7 pages, 6 figure

Nuclear resonant scattering of synchrotron radiation by physisorbed Kr on TiO2(110) surfaces in multilayer and monolayer regimes

Physisorbed Kr layers on TiO2(110) surfaces were investigated by means of nuclear resonant scattering (NRS) of synchrotron radiation at Kr thicknesses ranging from multilayer to monolayer. The NRS intensity was measured as a function of the Kr exposure, from which the NRS signal corresponding to monolayer was estimated as 0.23 cps. The time spectra measured at various thicknesses showed a monotonous decay without any quantum beat features. The recoilless fraction f evaluated from the analysis of the time spectrum revealed a substantial reduction upon temperature rise from 19 to 25 K. As its origin, an order-disorder phase transition of the monolayer Kr is proposed

Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor $\sim 10^{-4}$ compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL $= 90$) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

The Centromere:Chromatin Foundation for the Kinetochore Machinery

Since discovery of the centromere-specific histone H3 variant CENP-A, centromeres have come to be defined as chromatin structures that establish the assembly site for the complex kinetochore machinery. In most organisms, centromere activity is defined epigenetically, rather than by specific DNA sequences. In this review, we describe selected classic work and recent progress in studies of centromeric chromatin with a focus on vertebrates. We consider possible roles for repetitive DNA sequences found at most centromeres, chromatin factors and modifications that assemble and activate CENP-A chromatin for kinetochore assembly, plus the use of artificial chromosomes and kinetochores to study centromere function

350 AN INTFLLTGENT ROBOT WITH COGNITION AND DFCTSION-MAKING ABILITY

An intelligent robot that recognizes and assembles three-dimensional objects is described. The instruction to the robot is fed through a vidicon camera as a three-view plan of the assemblage whose overall spatial configuration is then recognized and decomposed into component parts by a computer. Another camera looks at the real world for the specific parts required for the assembly and confirms their geometric features. The computer further makes the decisions on the procedure for the manipulation of the parts, and orders the articulated mechanical hand to proceed the assembly sequence. The information processing is so far restricted to simple polyhedral objects and their co-relationships. Descriptive terms Intelligent robot, drawing recognition, assembly drawing, three-view plan, object recognition, three-dimensional objects, polyhedra, decision-making, assembly procedure, computer manipulation. 1

Poly-γ-glutamate Binder To Enhance Electrode Performances of P2-Na_2/3Ni_1/3Mn_2/3O₂ for Na-Ion Batteries

P2-Na_2/3Ni_1/3Mn_2/3O₂ (P2-NiMn) is one of the promising positive electrode materials for high-energy Na-ion batteries because of large reversible capacity and high working voltage by charging up to 4.5 V versus Na⁺/Na. However, the capacity rapidly decays during charge/discharge cycles, which is caused by the large volume shrinkage of ca. 23% by sodium deintercalation and following electric isolation of P2-NiMn particles in the composite electrode. Serious electrolyte decomposition at the higher voltage region than 4.1 V also brings deterioration of the particle surface and capacity decay during cycles. To solve these drawbacks, we apply water-soluble sodium poly-γ-glutamate (PGluNa) as an efficient binder to P2-NiMn instead of conventional poly­(vinylidene difluoride) (PVdF) and examined the electrode performances of P2-NiMn composite electrode with PGluNa binder for the first time. The PGluNa electrode shows Coulombic efficiency of 95% at the first cycle and capacity retention of 89% after 50 cycles, whereas the PVdF electrode exhibits only 80 and 71%, respectively. The alternating current impedance measurements reveal that the PGluNa electrode shows a much lower resistance during the cycles compared with the PVdF one. From the surface analysis and peeling test of the electrodes, the PGluNa binder was found to cover the surface of the P2-NiMn particles and suppresses the electrolyte decomposition and surface degradation. The PGluNa binder further enhance the mechanical strength of the electrodes and suppresses the electrical isolation of the P2-NiMn particles during sodium extraction/insertion. The efficient binder with noticeable adhesion strength and surface coverage of active materials and carbon has paved a new way to enhance the electrochemical performances of high-voltage positive electrode materials for Na-ion batteries

Fundamental Study on the Evaluation of the Vascular Lumen after Carotid Artery Stenting Using 3D-rotational Angiography with Diluted Contrast Medium

Objective: Due to the recent increase in the availability of cone-beam CT (CBCT), delineation of blood vessels and intracranial stents using CBCT has been well-reported, but reports using 3D-rotational angiography (3D-RA) have been few. We evaluated delineation of carotid artery stents using 3D-RA with diluted contrast medium.Methods: We prepared simulated blood vessel phantoms covered by carotid artery stents different in material and shape. The phantoms were encapsulated with different concentration of contrast medium, and scanned using 3D-RA. The appropriate concentration of contrast medium was evaluated.Results: The appropriate concentrations of diluted contrast medium were 50–17% for the Carotid Wall Stent (Boston Scientific, Natick, MA, USA) and 20%–10% for PRECISE (Johnson & Johnson, Miami, FL, USA) and PROTÉGÉ (Covidien, Irvine, CA, USA).Conclusion: The appropriate concentration of contrast medium varied with carotid artery stent. By selecting an appropriate degree of dilution, the stent shape, plaque, intimal thickening, and vascular lumen in the stent can be visualized. Therefore, it is possible to evaluate vascular lumen after carotid artery stenting