Observations of solar energetic particles at a synchronous orbit

The Space Environment Monitors (SEM) on board the Japanese geostationary meteorological satellites (GMS-1 and GMS-2) observed energetic protons, alpha particles and electrons continuously for February 1978 to September 1984. The satellites were at 6.6 Earth radii above 140 deg E equator

Possibility of Macroscopic resonant Tunneling near the Superconductor- Insulator Transition in YBaCuO Thin Films

Experimental results of I-V characteristics near the superconductor-insulator transition observed for disorder-tuned YBaCuO thinfilms are presented. The I-V characteristics exibit new quasiperiodic structures as a function of the current. The current interval, the number of the dI/dV peaks, and the magnetic field dependence of the peaks are consistent with the theoretical predictions of the resonant tunneling of a phase particle ina tilted-cosine potential for asingle Josephson junction with small capacitance.Comment: 7 pages, 4 figures, in press (Europhys. Lett.

Color Changes in Electronic Endoscopic Images Caused by Image Compression

In recent years, recording of color still images into magneto–optical video disks has been increasingly used as a method for recording electronic endoscopic images. In this case, image compression is often used to reduce the volume and cost of recording media and also to minimize the time required for image recording and playback. With this in mind, we recorded 8 images into a magneto-optical video disk in 4 image compression modes (no compression, weak compression, moderate compression, and strong compression) using the Joint Photographic Image Coding Experts Group (JPEG) system, which is a widely used and representative method for compressing color still images, in order to determine the relationship between the degree of image compression and the color information in electronic endoscopic images. The acquired images were transferred to an image processor using an offline system. A total of 10 regions of interest (ROls) were selected, and red (R), green (G), and blue (B) images were obtained using different compression modes. From histograms generated for these images, mean densities of R, G, and B in each ROI were measured and analyzed. The results revealed that color changes were greater for B, which had the lowest density, than for R or G as the degree of compression was increased

SHG microscopic observations of polar state in Li-doped KTaO3 under electric field

Incipient ferroelectric KTaO3 with off-center Li impurity of the critical concentration of 2.8 mol% was investigated in order to clarify the dipole glass state under electric field. Using optical second-harmonic generation (SHG) microscope, we observed a marked history dependence of SHG intensity through zero-field cooling (ZFC), zero-field heating (ZFH), field heating after ZFC (FH/ZFC) and FH after field cooling (FH/FC). These show different paths with respect to temperature: In the ZFC/ZFH process, weak SHG was observed at low temperature, while in the FH/ZFC process, relatively high SHG appears in a limited temperature range below TF depending on the field strength, and in the FC and FH/FC processes, the SHG exhibits ferroelectric-like temperature dependence: it appears at the freezing temperature of 50K, increases with decreasing temperature and has a tendency of saturation. These experimental results strongly suggest that dipole glass state or polar nano-clusters which gradually freezes with decreasing temperature is transformed into semi-macroscopic polar state under the electric field. However at sufficiently low temperature, the freezing is so strong that the electric field cannot enlarge the polar clusters. These experimental results show that the polar nano-cluster model similar to relaxors would be more relevant in KTaO3 doped with the critical concentration of Li. Further experiments on the anisotropy of SHG determine that the average symmetry of the field-induced polar phase is tetragonal 4mm or 4, which is also confirmed by the X-ray diffraction measurement.Comment: 26 pages, 8 figures, 1 tabl

Magnified Examination of Small Colorectal Polyps Using a Prototype Electronic Endoscope

Magnifying electronic endoscopes are frequently used to evaluate the pit patterns of the colorectal mucosa, but such endoscopes suffer from a number of problems. For example, they tend to have long, hard tips and heavy controller sections. In addition, the magnified endoscopic images obtained are often quite coarse due to the small number of pixels in the charge-coupled device (CCD). As a result, at higher magnification ratios, the orientation of the field of view is easily lost. A newly developed prototype colorectal electronic endoscope (Toshiba Corporation, Tokyo) overcomes these problems. The length of the hard tip of the scope and the weight of the controller section are comparable to those of the TCE-3680MH (Toshiba Corporation). High-resolution magnified images can be obtained, because a 410,000-pixel CCD is employed. Two magnification methods are available, optical magnification and electronic zooming, permitting images to be magnified by a factor of up to 90–120 without losing the orientation of the field of view. This newly developed magnifying electronic endoscope was found to be very useful, allowing us to observe the pit patterns of the colorectal mucosa in 82 small colorectal polyps measuring 7 mm or less in diameter

A Woods-Saxon Optical-Model Description of 14N Elastic and Inelastic Scattering from 27Al and 28Si

開始ページ、終了ページ: 冊子体のページ付

Analysis of Buoyancy-Driven Ventilation of Hydrogen from Buildings: Preprint

When hydrogen gas is used or stored within a building, as with a hydrogen-powered vehicle parked in a residential garage, any leakage of unignited H2 will mix with indoor air and may form a flammable mixture. One approach to safety engineering relies on buoyancy-driven, passive ventilation of H2 from the building through vents to the outside

Analysis of Buoyancy-Driven Ventilation of Hydrogen from Buildings

The scope of work for this project includes safe building design, vehicle leak in residential garage, continual slow leak, passive, buoyancy-driven ventilation (versus mechanical), and steady-state concentration of hydrogen versus vent size