EXAFS study on the sulfidation behavior of Pd, Pt and Pd–Pt catalysts supported on amorphous silica and high-silica USY zeolite

The sulfur tolerance of monometallic Pd, Pt and bimetallic Pd–Pt catalysts supported on slightly acidic ultra-stable Y (USY) zeolite (SiO₂/Al₂O₃ = 390) and on non-acidic silica, having mesopores with a pore diameter of 3 or 10 nm, were investigated using the CO adsorption method and the extended X-ray adsorption fine structure (EXAFS) method. Well-dispersed noble metal particles supported on USY zeolite and silica with an average pore diameter of 3 nm showed high surface sulfur tolerance and high catalytic hydrogenation activity, although bulk phase sulfidation simultaneously occurred. The synergistic effects of sulfur tolerance were significant in the bimetallic Pd–Pt particles supported on USY zeolite and silica with an average pore diameter of 3 nm. On the other hand, on silica with an average pore diameter of 10 nm, the surface sulfur tolerance of low dispersed noble metals was the lowest, although its bulk phase sulfur tolerance was the highest. The Pd K-edge and Pt L_III-edge EXAFS spectra indicated a strong interaction between the well-dispersed noble metal particles and the supports of the USY zeolite and silica with an average pore diameter of 3 nm. This distorted structure may increase the sulfur tolerance of noble metals, though some surface and bulk phase sulfidation simultaneously occurred.     

Study of Fabry-Perot Cavities with Metal Mesh Mirrors Using Equivalent Circuit Models. Comparison with Experimental Results in the 60 GHz Band

The equivalent circuit modelling technique is used to study the resonant frequency and Q factor of plane parallel Fabry-Perot cavities with square aperture metal mesh mirrors. Comparison of different models found in literature with experimental data in the 60 GHz band is given for thin and thick cavities. Chen's model is shown to give a good agreement with measurements, as long as the cavity is not too selective and for large enough cavity.     

Intra- and interbreed genetic variations of mitochondrial DNA major non-coding regions in Japanese native dog breeds (Canis familiaris)

Mitochondrial DNA (mtDNA) major non-coding regions were amplified from 73 dogs of eight Japanese native dog breeds and from 21 dogs of 16 non-Japanese dog breeds by the polymerase chain reaction and their DNA sequences were determined. A total of 51 nucleotide positions within the non-coding region (969-972 base pairs) showed nucleotide variations of which 48 were caused by transition. These nucleotide substitutions were abundant in the region proximate to tRNA(Pro). In addition to the nucleotide substitutions, the dog mtDNA D-loop sequences had a heteroplasmic repetitive sequence (TACACGTAGCG) involving size variation. The DNA sequences of the non-coding region were classified into four different groups by phylogenetic analysis and the deepest branchpoints of this dog phylogeny was calculated to about 100,000 years before the present. Phylogenetic analysis showed that Japanese native dog breeds could not be clearly delimited as distinct breeds. Many haplotypes found in members of some clustering groups were seen in each dog breed, and interbreed nucleotide differences between Japanese dog breeds were almost the same as the intrabreed nucleotide diversities.     

Segmental hyperintensity on T1-weighted MRI of the liver: indication of segmental cholestasis

The purpose of this study was to determine the relationship between segmental hyperintensity of the liver on T1-weighted images and segmental cholestasis in patients with obstructive jaundice. T1-weighted and T2-weighted MR images were obtained of 73 patients with obstructive jaundice caused by various diseases. Fat-suppressed T1-weighted images were also obtained of 10 patients. Eleven patients with segmental intrahepatic bile duct dilatation (cholestasis) showed segmental hyperintensity on T1-weighted images and/or fat-suppressed T1-weighted images and no signal intensity difference on T2-weighted images. Sixty-two patients with widespread intrahepatic bile duct dilatation showed no intensity difference on T1-weighted and T2-weighted images (P < .01). Segmental hyperintensity on T1-weighted images was correlated with intrahepatic cholestasis.     

A case of axonal form of Guillain-Barré syndrome associated with anti-GM1b IgG antibody following Penner 4 Campylobacter jejuni infection

A 48-year-old man with an extensive history of alcoholism was found dead at home. He was lying face down on a carpet. There was evidence of gastric aspiration at autopsy and histologic examination. The distribution of ethanol was very unusual (concentrations in mg/100 mL or mg/100 g): femoral blood, 257 and 273 (two samples); heart blood, 643; vitreous humor, 763; urine, 84; bile, 616; liver, 250; and gastric, 4660 (2470 mg/53 g). In addition, this man ingested isopropanol, and, according to the history, may also have ingested acetone in the form of nail polish remover. The distribution of both isopropanol and acetone was as expected, which was approximately in proportion to the aqueous content of the respective tissues. It is proposed that agonal or postmortem aspiration of the ethanol-rich vomitus and postmortem fermentation could account for the apparently elevated concentrations of ethanol in heart blood and bile. The elevated vitreous ethanol could be explained if ethanol diffused across the eye in the agonal phase or postmortem from gastric aspirate in the carpet. The relatively low urinary ethanol concentration would be consistent with a recent binge-drinking episode, which allowed only a limited time period for excretion into an already partially full, but relatively ethanol-free, bladder.     

Super-high-/spl Delta/ athermal arrayed waveguide grating with resin-filled trenches in slab region

A small and low-loss athermal AWG is demonstrated based on super-high-/spl Delta/ waveguides. Resin-filled trenches are formed in the slab region to compensate for the temperature-dependent wavelength shift. Small wavelength shift of 0.03 nm is achieved for the temperature range 0-65/spl deg/C with almost no spectral degradation.     

神户钢铁公司高炉高煤比喷吹

介绍了高炉煤粉大喷吹所要求的理论和方法.文章以中心加焦时进行的炉料分布控制,以获得稳定的软熔带形状的历史发展为起点,讨论了用于氧煤复合喷吹的双枪回旋区燃烧技术.依托这些改进技术,神户3号高炉地震后炉况的恢复以及加古川厂3号高炉开炉后的喷煤情况都很先进和顺利.文章最后分析了新世纪高炉在经济和环境方面未来的发展.     

Dynamic bottleneck control in wide variety production factory

At a factory which produces a wide variety of products such as ASIC's or microcomputers, it is necessary to detect any machine causing a bottleneck and return it to a high level of performance for fast and effective production. This paper introduces a workflow control system called “JUSTICE/MORAL” (just time process control system/method of optimum-buffer restriction and adjustment logic) which dynamically detects a machine causing a bottleneck and feeds work to that machine at an appropriate time. The advantages of this system are as follows: (1) manufacturing cycle time can be reduced by an average of 13% and a maximum of 50% and (2) throughput can be increased up to approximately 10%. Part of this system has been installed in our factory. We have seen factory cycle time improve by approximately 20% in the two month period from July to September 1998. Also, the machine causing the bottleneck was found quickly; as a result, the utilization of this machine increased by 3%,     

Long pedunculated colonic polyp composed of mucosa and submucosa: proposal of a new entity, colonic muco-submucosal elongated polyp

We encountered 15 patients with colonic polyps showing histologic features that did not belong to any of the known categories. All polyps were elongated and drumstick-shaped, with lengths of 12 to 160 (mean, 29 mm) mm. Histologically, the polyps were covered with normal mucosa and consisted of edematous, loose, fibrous, connective tissues and dense, fibrous submucosal layers, often showing dilation of blood vessels and lymphatics. Although the mechanism of generation of such polyps remains unknown, their elongation may be caused by intestinal motion. Because this kind of polyp has not been described previously outside Japan, we here introduce a new type of polyp, which we have proposed calling the colonic muco-submucosal elongated polyp.     

A case of progressive multiple focal nodular hyperplasia with alteration of imaging studies

Focal nodular hyperplasia (FNH) of the liver is a lesion characterized by a well circumscribed region of hyperplastic liver tissue with stellate fibrosis. The pathogenesis of the lesion is unknown but various authors consider that FNH may be a response to a preexisting vascular abnormality. We experienced a case of progressive multiple FNH, in which the hemodynamic change as shown by imaging modalities, may support this hypothesis. The patient, a 38-yr-old woman, was found by chance to have multiple portal venous shunts and multiple FNH in both lobes of her liver. Because of their benign characteristics, we followed the nodules periodically without any special treatment. After about 4 yr, the nodules increased both in size and number. In addition, digital subtraction angiography showed that the diameter of the artery had become larger. The hemodynamic change revealed by imaging studies in this case supports the hypothesis that one of the pathogens of FNH is a secondary hepatocellular response to arterial hyperperfusion caused by some vascular malformations.