Fabrication of high-quality long-fiber Bragg grating by monitoring 3.1-eV radiation (400 nm) from GeO defects

3.1-eV (400-nm) luminescence is generated by UV radiation at 244 nm and guided in a germanium-doped silica fiber. In this letter, we propose a new technique for fabricating a fiber Bragg grating by monitoring the power of this visible light. The UV beam is scanned so as to maximize the visible light caused by the UV radiation. This enables us to fabricate successfully a chirp-free and high quality fiber Bragg grating.     

Development of a 275-kV liquid cooling-type gas-insulated transformer

Construction of 275-kV and 500-kV substations in densely populated areas is thought to be necessary in the future to maintain a stable supply of electricity. The use of gas-insulated transformers is now considered for substations because such transformers are non-flammable and nonexplosive. Since the completion of the 77-kV gas-insulated transformer in 1979, we have continued research to develop gas-insulated transformers applicable to a higher voltage level up to 500 kV. As the results of the research, 275-kV, 300-MVA a liquid cooling-type gas-insulated transformer has been developed.     

Protective activity of Borrelia duttonii-specific immunoglobulin subclasses in mice

To analyse the immune response of mice to Borrelia duttonii infection, BALB/c mice were inoculated intraperitoneally with B. duttonii strain 406K, and the titres of B. duttonii-specific immunoglobulins - IgM, IgG1, IgG2a, IgG2b and IgG3 - were determined by ELISA. IgM antibodies appeared first, followed by IgG2a and IgG3, and then IgG1 and IgG2b. The protective activity of individual classes and subclasses of B. duttonii-specific immunoglobulins was then determined by passive immunisation of BALB/c mice with immunoglobulin preparations purified by affinity chromatography. The mice were then challenged by intraperitoneal inoculation of B. duttonii. The study demonstrated that B. duttonii-specific IgM and IgG3 protected against the development of spirochaetaemia and death after borrelial infection, whereas B. duttonii-specific IgG1, IgG2a and IgG2b had low protective activities.     

Radioimmunoassay of main urinary metabolite of prostaglandin F2alpha

Radioimmunoassay of 5alpha, 7alpha-dihydroxy-11-keto-tetranorprosta-1,16-dioic acid, main urinary metabolite of prostaglandin F2alpha (PGF2alpha), was performed using an antiserum produced in the rabbit. The antibody in 100 mu1 of 1,600-fold diluted antiserum binds with 60 picograms of metabolite. The main urinary metabolite level fell when flufenamic acid, a prostaglandin synthetase inhibitor, was given to rats. In contrast, it was significantly elevated when PGF2alpha was administered.     

Vinyl polymerization, 399. Polymerization of methyl methacrylate with sodium polystyrenesulfonate in presence of polyethyleneglycol

The effect of polyethyleneglycol on the radical polymerization of methyl methacrylate initiated with an aqueous solution of sodium polystyrenesulfonate was studied. Under the definite condition, the conversion of methyl methacrylate raised from 6.6 to 100% by the addition of polyethyleneglycol. It was concluded that polyethyleneglycol acted only as a host of Na⁺, but not as a phase transfer catalyst.     

FM eliminated CH4locked frequency stabilization of 3.39 µm He-Ne laser in dual feedback control

The frequency of the 3.39 μm He-Ne laser was locked to the CH4saturated absorption line by means of integral-proportional feedback control, i.e., dual feedback control. The frequency modulation was applied by a vibrating mirror placed outside a laser cavity, obtaining a modulation-free laser beam with a stabilized frequency. The long-term stability achieved under integral feedback control was aboutpm1.1 times 10^{-11}, which was further improved topm1.35 times 10^{-12}under dual feedback control. The Allan variance measured by the photomixing technique was1.77 times 10^{-12}at an averaging time 100 s.     

Novel method for site-controlled surface nanodot fabrication by ion beam synthesis

By using a Ga FIB system to spatially control the implantation of Ga into SiO(2) followed by vacuum annealing, we have fabricated self-assembled surface Ga nanodots with a high degree of control of nucleation location. The morphology of the Ga nanodots is closely related to Ga dose, showing a critical dose needed for nucleation that results in Ga nanodot formation just below the surface, while at higher doses Ga nanodots form on the surface as metallic Ga droplets. Possible applications include defining nucleation sites for subsequent growth, use as Ga source for GaN or GaAs quantum dots, or as catalyst for nanowire growth.     

Use of cholinesterase activity as an indicator for the effects of combinations of organophosphorus pesticides in water from environmental sources

Organophosphorus pesticides (OPs) are commonly detected in agricultural products, animal-derived foodstuffs, and environmental samples. Until now, the focus of research has been to evaluate the adverse effect of a single OP. While each OP may be present at concentrations under recognized as “no observed adverse effect level (NOAEL)”, the combined effects of multiple OPs present at these low concentrations have not been sufficiently studied. Therefore, we developed an in vitro testing method to evaluate the toxicity of multiple OPs based on the degree of inhibition of cholinesterase (ChE) activity. This method requires only 10 min to complete and no specialized technology. We examined 15 OPs by this method and categorized them into three groups according to the degree of ChE inhibition. A relationship between the OPs’ chemical structures and the degree of ChE inhibition emerged with the moiety –P–O–CN– showing the strongest action. The degree of ChE inhibition increased with multiple OPs, and the degree of inhibition seemed to be additive. These results demonstrate that the combined toxicity of multiple OPs present in food or environmental samples is an easily determined and toxicologically relevant measure of overall toxicity of complex OPs mixtures. It is possible to apply this testing method as a monitoring technique in water quality management in order to control OPs. As a result, this method can play the role for the potential risk reduction to the ecosystem and may contribute to the preservation of the environment.