An effective method for coupling single-mode fiber to thin-filmwaveguide

An effective method for coupling optical signals from single-mode fibers to thin-film waveguides is proposed. The authors show that this method provides high coupling efficiency for connecting fibers of different core diameters to thin-film waveguides of different film thicknesses or refractive indexes. The authors summarize the theoretical treatment of the coupler. Examples of couplers designed for SiO₂ -based materials as well as iron garnets are presented. Fabrication of the proposed coupler and its experimental results are described     

Antiphospholipid syndrome complicated by thrombosis of the superior mesenteric artery, co-existence of smooth muscle hyperplasia

A 37-year-old woman underwent an emergency operation at our hospital because of severe abdominal pain and ileus. Most of her small intestine and ascending colon were observed to have become necrotic due to occlusion of her superior mesenteric artery (SMA). Pathological findings of the resected intestine revealed that her SMA was completely thrombosed 2 cm distal from its origin with smooth muscle proliferation. Post-surgical blood analysis of her pre-operative serum was positive for lupus anticoagulant and antinuclear antibodies. She noticed vaginal bleeding due to missed abortion on the 31st day after the operation. We diagnosed her acute abdominal pain to be that of antiphospholipid syndrome associated with her pregnancy.     

Velocity and turbulence measurements in a cylindrical bath subject to centric bottom gas injection

Laser Doppler velocimeter (LDV) measurements were made to clarify the fluid flow behavior in a bath subject to centric bottom gas injection. Correlations of the axial mean velocity and turbulence components in the gas-liquid two-phase flow region,i.e., in the bubbling jet region, were proposed as functions of the inner diameter of nozzle, gas flow rate, and densities of gas and liquid. Measured values of the flow rate, momentum, and kinetic energy of water rising upward were approximated satisfactorily by these empirical correlations. In addition, the Reynolds shear stress was calculated and compared with measured values. Formerly Graduate Student, Osaka University,     

Molecular dynamics simulation of dislocation nucleation and motion at γ/γ′ interface in Ni-based superalloy

Molecular dynamics simulations are conducted on the dislocation behavior at the apices and edges of cuboidal Ni₃Al precipitate in a pure Ni matrix, or the idealized γ/γ′ microstructure in a Ni-based superalloy. A tensile simulation of the [001] direction is implemented with a periodic cell that has eight cubic precipitates in order to investigate the nucleation site of dislocation in the idealized microstructure with no defects other than the γ/γ′ interfaces. The effect of residual internal stresses on the stability of the interfaces is also discussed. Other simulations are conducted on the behavior of edge dislocations nucleated from a free surface and proceeding in the γ matrix toward γ′ precipitates under shear force. Dislocation pinning at γ′ precipitates, bowing-out in the γ channel, pile-up and nucleation of superdislocation in the γ′ precipitate are simulated and inspected in detail. Discussions on the size of the γ/γ′ microstructure and the sharpness of the edge of the γ′ precipitate are also presented.     

Thermophysical properties of silicate slags

The optimization of metallurgical processes requires reliable data of the slag phase. This paper focuses on three properties that are relevant to heat and mass-transfer calculations — viscosities,thermal diffusivities, and surface tensions of silicate melts. A brief account of the experimental techniques used for the measurements of these properties, with special reference to the work carried out in the Division of Metallurgy, Royal Institute of Technology, Stockholm, Sweden, are presented, along with the advantages and limitations. As these properties are structure-oriented, the impact of structure on these properties is also presented. The paper is intended as a state-of-the-art review of the subject.     

Effects of distraction on physiologic integrity of the spinal cord, spinal cord blood flow, and clinical status

The authors determined the effects of distraction of the spine on physiologic integrity of the spinal cord using neurogenic motor evoked potentials (NMEPs), somatosensory evoked potentials (SEPs), spinal cord blood flow measurements, and clinical status in nine hogs. Spinal cord blood flow was measured after each level of distraction using the hydrogen washout technique. The results indicated that blood flow of at least 65% of baseline was required to maintain physiologic integrity of the spinal cord, and that a decrease of blood flow to 12% of baseline was associated with paraplegia. Neurogenic motor evoked potentials always correlated with the animal's postsurgical clinical status, whereas the SEP was falsely negative in one animal.     

Japanese surname regions

This paper uses an extended case study of Japan to illustrate how surnames, or family names, can be used as a basis for regionalization. We undertake a comparison between inductively surname regions of Japan with areal geographies based upon both contemporary and historical prefecture (administrative) units. The work is seen as using highly disaggregate framework data to evaluate the integrity of the areal units that are used in regional science. It also is relevant to understanding population distributions, past and present, and the consequences of local, regional and national residential mobility and migration.     

CFD analysis of a high‐speed unsteady jet

The flow of a high‐speed unsteady jet is analyzed using computational fluid dynamics for an incompressible flow with the k–ε turbulence model. The pseudo‐nozzle concept is applied to the inlet condition with a large pressure gradient. The results show that the time history of the jet development agrees with the experimental data for methane and hydrogen fuels. In addition, the effect of the injection condition on the development of the jet tip is well described with this model. Furthermore, the effects of inlet conditions of the turbulence intensity and scale on the flow are investigated. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(1): 1– 12, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20141     

Effects of high magnetic fields on solidification microstructure of Al–Si alloys

The effects of high magnetic fields on the solidification microstructure of Al–Si alloys were investigated. Al–7.2 wt%Si and Al–11.8 wt%Si alloys were solidified in various high magnetic fields at different cooling rates. The secondary dendrite arm spacing (SDAS) of the primary Al dendrites and the lamellar spacing (LS) of the eutectics were measured. It was found that the application of a high magnetic field could decrease the SDAS of the primary Al dendrites in Al–7.2 wt%Si alloys and the LS of the eutectics in Al–11.8 wt%Si alloys. The effects of the high magnetic field on the SDAS decreased with increasing cooling rate. The decrease in the SDAS and LS can be attributed to the decrease of the solute diffusivity in the liquid ahead of the solid/liquid interface during the growth of the dendrite and eutectic. This decrease is caused by the high magnetic field which can damp the convection and avoid its contributions to the diffusion.