Diagnosis of superficial-type early carcinoma of the gallbladder by endoscopic ultrasonography--comparison with ultrasonography

The detectability of superficial-type carcinoma of the gallbladder by ultrasonography (US) and endoscopic ultrasonography (EUS) were investigated. Eight patients with such carcinoma of the gallbladder were reviewed. They had undergone both US and EUS previous to surgery. The tumor was detected in 3 patients by US, 2 patients with IIa + IIb-type carcinoma and 1 patient with IIa-type carcinoma. Those lesions were visualized as localized thickening of the gallbladder wall or as broad-based tumor. In 2 patients, lesions were not initially detected by US, but were shown by US after the examination by EUS. The tumor was detected by EUS also in 1 case of IIb + IIa-type carcinoma besides those 3 patients mentioned above. All four of these lesions were visualized as broad-based tumor by EUS. It was difficult to detect pure IIb-type or small IIa-type carcinoma even by EUS. In patients with concomitant acute cholecystitis or gallbladder stone, it was difficult to evaluate the abnormal findings of the gallbladder wall.     

Clog detection method in metal tubes using group delay characteristics in electromagnetic waves

In large‐scale factories or power plants metal tube clogging sometimes leads to serious accidents. However, metal tube testing for the detection of foreign objects requires a long testing time and considerable effort. Therefore, we proposed an original inspection method of a single metallic tube using electromagnetic wave reflection in the tube. However, for branched tubes, it is difficult to estimate the position of the clog by electromagnetic wave reflection. To evaluate the position of clog in the branched tubes, we proposed a new detection method using the group delay time in electromagnetic waves. The group delay time in electromagnetic waves is slightly affected by the bifurcation area. To verify the new method, the group delay time characteristics were measured in the branched tubes. The position of clog could be easily detected by the proposed method.     

Structural characteristics and optical properties of a series of solvatochromic fluorescent dyes displaying long-wavelength emission

A series of novel, fluorescent, solvatochromic dyes (KSD-series) carrying a 4-dimethylaminophenyl moiety as π-electron donor and an acetyl moiety as π-electron acceptor, conjugated with a five-membered aromatic monoheterocyclic π-linker, were synthesized. In the cases of dyes having a pyrrole, (KSD-1) furan (KSD-2) and thiophene (KSD-3) heterocycle as π-linker, respectively, the plot of Stokes shifts in different solvents as a function of E_T(30) solvent polarity value showed good linear correlation. The fluorescence of KSD-4, a π-conjugation extended derivative of KSD-3, varied from blue (491 nm) in toluene to orange (616 nm) in DMSO; KSD-4C, a carboxyl group modified derivative, displayed longer wavelength emission (619 nm) and larger Stokes shift (229 nm, 9486 cm^?1) than conventional dyes in methanol solution.     

Coarsening kinetics of multicomponent MC-type carbides in high-strength low-alloy steels

Morphology and coarsening kinetics of MC-type carbide (MC-carbide) precipitating during the tempering process have been investigated in V- and Nb-bearing Cr-Mo martensitic steels. Detailed transmission electron microscopy (TEM) observations show that the addition of V and Nb stabilizes the B1-type MC-carbide instead of L’3-type M₂C-carbide. The morphology of the MC-carbide is characterized as disk-like with Baker and Nutting orientation relationships with the matrix. When the specimens are fully solution treated followed by quenching, the MC-carbide precipitates as a multicomponent system with continuous solid solution of VC, NbC, and MoC. The V-, Nb-, and Mo-partitioning control the lattice parameter of MC-carbide and consequently affect the coherency between MC-carbide and the matrix. The coherent MC-carbide grows into an incoherent one with the progress of tempering. The numerical analysis on TEM observations has shown that the coarsening kinetics of MC-carbide is equated to (time)^1/5 criteria, while the coarsening kinetics of the coexisting cementite is equated to (time)^1/3 criteria. It is thus suggested that the Ostwald ripening of MC-carbide is controlled by pipe diffusion of V, Nb, and Mo along dislocations. It has been confirmed that the coarsening rate of the multicomponent MC-carbide is affected by V, Nb, and Mo content. Applying the thermodynamic solution database, the rate equation for MC-carbide coarsening can be expressed as a function of V, Nb, and Mo content, and the activation energy for pipe diffusion can be estimated as ΔQ _v: ΔQ _Nb: ΔQ _Mo=1:3.9:0.6.     

Thin electromagnetic wave absorber for quasi-microwave bandcontaining aligned thin magnetic metal particles

Soft magnetic material has been produced in which flaky thin amorphous metal particles, about 2 μm thick, are aligned in polymer in the direction perpendicular to electromagnetic wave propagation. This material yields a permeability two to three times higher than the spinel-type ferrite system in the quasi-microwave band. We have designed a thin wave absorber composed of the present material by introducing a low-permittivity area such as a free space into the present metal-containing material. This decreases the average permittivity, striking a balance between complex permeability and permittivity values, and thus reducing the reflection coefficient of the absorber. A thin (about 3-mm thick) wave absorber with a reflection loss of over 30 dB in the quasi-microwave band was successfully obtained when the free space region was 5% of the total volume     

PL and EL properties of Tm-activated vanadium oxide-based phosphor thin films

The preparation of high-luminance blue emitting Tm-activated multicomponent oxide phosphor thin films is described. The phosphor thin films were deposited on thick BaTiO₃ ceramic sheets by r.f. magnetron sputtering using powder targets. A very high photoluminescence (PL) intensity in blue emission could be observed in postannealed Tm-activated gadolinium oxide-vanadium oxide Gd_0.5-V_0.5-O:Tm thin films prepared using Tm₂O₃-doped (Gd₂O₃)_0.5-(V₂O₅)_0.5 targets (V₂O₅ content of 50 mol.%). It should be noted that thin films of this phosphor postannealed at 1100 °C in air exhibited higher PL intensity than those from commercially available blue BaMgAl₁₄O₂₃:Eu (BAM) phosphor powder and Gd_0.5-V_0.5-O:Tm powders. In addition, a Gd_0.5-V_0.5-O:Tm thin-film electroluminescent device exhibited a blue emission that was the same as the PL emission.