2 × 2 optical waveguide matrix switch using nematic liquid crystal

A 2 × 2 nonblocking optical matrix switch, composed of four elemental switches formed in a slab waveguide, is described. Switching action is based on total internal reflection caused by an electrically controlled change in refractive index of the liquid crystal. Propagation loss was remarkably reduced to 2.3 dB/cm, both by using liquid crystal as a cladding layer and by operating at the 1.31 μm wavelength. The experimental matrix switch exhibited 7.3-7.7 dB insertion loss, -17.3 to -18.2 dB crosstalk, and a 14° switching angle.     

SAXS study on crystallization of an amorphous Pd76Au6Si18 alloy

The crystallization behaviour of an amorphous Pd₇₆Au₆Si₁₈ alloy has been investigated mainly by means of small angle X-ray scattering measurements. The amorphous alloy crystallized to form MS-I phase with composition Pd₇₈Au₂₂ in the amorphous matrix, which later crystallized as MS-II. The crystallization kinetics of MS-I phase were analysed in the framework of conventional nucleation theory. It was suggested that the considerable number of nuclei of MS-I phase had been already formed in the as-quenched specimen and the remaining nucleation attained within the short period of isothermal ageing. The remarkable increase of the scattering intensity corresponded to the growth of MS-I phase, the kinetics of which were found to be controlled by the diffusion mechanism. The interdiffusion constant was obtained fromD=6.0×10¹⁵ exp (–420 kJ mol^–1/RT) m² sec^–1, which agreed fairly with the reported values.     

Waveguide-type optical passive ring-resonator gyro using time-division detection scheme

An optical passive ring-resonator gyro is demonstrated using a waveguide ring-resonator and a conventional distributed feedback laser diode. A novel detection technique for the Sagnac effect based on a time-division switching scheme is also proposed.<>     

Phosphor-doped silica cladding v.a.d. fibres

Loss reduction of v.a.d. (vapour-phase axial deposition) fibres at wavelengths of 1.3 ?m and 1.6 ?m was investigated. The infrared absorption loss was reduced by applying SiO2-P2O5 cladding instead of SiO2-B2O3 cladding and by minimising the waveguide imperfection loss. The minimum losses of the fabricated v.a.d. fibre were 0.5 dB/km and 0.28 dB/km at wavelengths of 1.3 ?m and 1.6 ?m, respectively. This fact indicates that fibres fabricated by the soot process, like those made by the vapour-phase axial-deposition process, can be used as long-wavelength optical transmission media. We have also found the OH absorption abnormality at wavelengths of 0.95, 1.24 and 1.39 ?m, and the loss peak values are different from those reported.     

Motor Core Iron Loss Analysis Evaluating Shrink Fitting and Stamping by Finite-Element Method

We describe a method to analyze the effects of shrink fitting and stamping on the mechanical stress distribution and iron loss in motor cores. Shrink fitting and stamping are important processes in manufacture of motor cores from electrical steel. The mechanical stress distribution is evaluated by a structural finite-element method, and the iron loss is evaluated by combined analysis of the electromagnetic field (by a finite-element method) and mechanical stress. The method clearly shows that the iron loss becomes larger as the width of the shrink fit increases, an effect borne out by experiment. In regard to the effect of stamping, calculation results again agree well with experimental data     

Changes in Endogenous Oxytocin Levels and the Effects of Exogenous Oxytocin Administration on Body Weight Changes and Food Intake in Polycystic Ovary Syndrome Model Rats

Polycystic ovary syndrome (PCOS) is frequently seen in females of reproductive age and is associated with metabolic disorders that are exacerbated by obesity. Although body weight reduction programs via diet and lifestyle changes are recommended for modifying reproductive and metabolic phenotypes, the drop-out rate is high. Thus, an efficacious, safe, and continuable treatment method is needed. Recent studies have shown that oxytocin (OT) reduces body weight gain and food intake, and promotes lipolysis in some mammals, including humans (especially obese individuals), without any adverse effects. In the present study, we evaluated the changes in endogenous OT levels, and the effects of acute and chronic OT administration on body weight changes, food intake, and fat mass using novel dihydrotestosterone-induced PCOS model rats. We found that the serum OT level was lower in PCOS model rats than in control rats, whereas the hypothalamic OT mRNA expression level did not differ between them. Acute intraperitoneal administration of OT during the dark phase reduced the body weight gain and food intake in PCOS model rats, but these effects were not observed in control rats. In contrast, chronic administration of OT decreased the food intake in both the PCOS model rats and control rats. These findings indicate that OT may be a candidate medicine that is efficacious, safe, and continuable for treating obese PCOS patients.     

Formation of Titanium Sulfide from Titanium Oxycarbonitride by CS2 Gas

Metallurgical and Materials Transactions B - Previously this group reported that a good quality titanium metal powder can be produced from titanium sulfides by electrochemical OS process. In this...