Publications by authors named "Shun-ichi Hayashi"

A novel microwave-induced helium plasma optical emission spectrometry (He-MIP-OES) combined with a thermal hydrolysis sample introduction system was newly established for the determination of fluorine (F) compounds in slags. The MIP maintained through an Okamoto cavity was adopted, which was quite stable and provided a higher detection capability of F by helium plasma. The basic analytical performance of He-MIP-OES combined with an ultrasonic nebulizer for F analysis was also examined, and expected results could be obtained.

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Laser post-ionization of sputtered molecules by pulsed Ga focused ion-beam (Ga-FIB) bombardment was examined for the detection and imaging of polycyclic aromatic hydrocarbons (PAHs) on particles. As model samples, pyrene and pelyrene adsorbed on TiO2, blended regents of pyrene and n-heneicosan were used. The TiO2 particle size was selected to be several micro-meters.

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The chemical states of boron in coal fly ash, which may control its leaching into the environment, were investigated by focused-ion-beam time-of-flight secondary ion mass spectrometry (FIB-TOF-SIMS) and satellite-transition magic angle spinning nuclear magnetic resonance (STMAS NMR) spectroscopy. The distribution of boron on the surface and in the interior of micron-sized fly ash particles was directly observed by FIB-TOF-SIMS. Coordination numbers of boron and its bonding with different atoms from particles of bulk samples were investigated by STMAS NMR.

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For the analysis of trace amounts of hazardous organic compounds, we developed a new ion detection system for supersonic jet resonance-enhanced multiphoton laser ionization mass spectrometry. High sensitivity and selectivity have been achieved by combining a proto-type Daly detector, a newly designed conical ion lens, and a potential switch that can perform the function of a mass selector. This ion detection system enables us to bring the jet nozzle closer to the ionization point.

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Objective: There are a number of views on the indication for endoscopic papillary balloon dilation (EPBD) in the management of bile duct stones. In this study, we have evaluated the efficacy and safety of EPBD compared with endoscopic sphincterotomy (EST).

Design: Prospective randomized trial.

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