Mariko Ono-Ogasawara

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The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron(More)
Diesel engines are widely used in industries, for example transportation, mining, and construction, because they efficiently produce high power. In diesel exhaust particles (DEP), the number of ultrafine particles, less than around 100 nm, is dominant in contrast to mass size distribution. Carcinogenic PAHs may be adsorbed on DEP at high concentrations. As(More)
A male worker who handled thallium-containing raw material for glass manufacturing over a period of four years complained of alopecia, abdominal pain, diarrhea and tingling in the four extremities. Neurological examination of this patient revealed signs of mild glove-stocking-type polyneuropathy. Lower sensory nerve conduction velocity of the median nerve(More)
As multi-wall carbon nanotubes (MWCNTs) come to be used in a wider range of products, increasing production is expected to result in greater exposure of workers to MWCNTs. In this research, we present a method for evaluating the concentration of MWCNT aerosols distinctively on the basis of the elemental carbon (EC) concentration. Respirable dust is sampled(More)
OBJECTIVES In order to assess the exposure risks of multiwall carbon nanotubes (MWCNT) for packing workers, we carried out real-time monitoring in the two types of packing facilities of MWCNT, and exposure measurements for the packing workers. METHODS In the real-time monitoring, a scanning mobility particle sizer (SMPS) and an optical particle counter(More)
Various applications of multiwalled carbon nanotubes (MWCNT) have been developed. One of these applications is an efficient sheet heating element that is woven from MWCNT-coated yarn. In this research, we assessed the exposure to MWCNT and/or the probability of particle release from broken MWCNT-coated yarn during the weaving process. This was accomplished(More)
A method for determining phosphine was developed using adsorption sampling followed by colorimetric measurement. Two types of adsorbent used in this study were prepared from silica gel by impregnation with potassium permanganate (1% w/w) or (mercury(II) chloride and sodium chloride) (0.2 + 0.2% w/w). Each adsorbent (150 mg) packed in a glass tube had the(More)
A simple direct injection method for analysis of polycyclic aromatic hydrocarbons (PAHs) or other organic components of particulate matter by gas chromatography/mass spectrometry (GC/MS) was developed. This method uses a small custom brass capsule to insert a particulate sample deposited on a quartz fiber filter or powdery sample directly into a GC injector(More)
A method for determining atmospheric diborane in concentrations higher than 1/10 of TLV, i.e., 0.01 ppm, has been developed using the adsorption sampling method. Silica gel impregnated with potassium permanganate, synthetic resin activated carbon impregnated with or without mercury(II) chloride and activated carbon impregnated with chromate salt showed(More)
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