An analytical method for three-dimensional non-linear responses of prestressed concrete nuclear reactor vessels

This paper describes the results of an investigation to develop an analytical method for assessing the non-linear behaviour and strength of three-dimensional concrete structures such as prestressed concrete nuclear reactor vessels (PCRVs) under monotonically increasing internal pressure. This three-dimensional finite element method uses a proposed material model for the non-linear response of concrete under a multiaxial stress state. Three numerical examples were analysed to investigate the feasibility of the analysis. The first was the calculation of the two-dimensional response of Kupfer's plain concrete. The second involved the analysis of a small-scale axisymmetric PCRV test model with a solid end slab. The third was the analysis of a three-dimensional PCRV test model with penetrations in the end slab. Good agreeement between experimental and analytical results was obtained.     

BSO/fibre-optic voltmeter with excellent temperature stability

A new BSO/fibre-optic voltmeter for measurement of AC voltage from 0 to 500 V has been successfully developed for practical use in various fields. This voltmeter has been given outstanding temperature stability of within ± 0.2% from ?10°C to 85°C by using the electro-optic effect of a 4.7 mm-thick Bi12SiO20.     

8C1--The laser current transformer for EHV power transmission lines

A current measuring device applicable to an extra-high voltage power transmission line higher than 500 kV is proposed with preliminary experimental results. It obtains the instantaneous magnetic field ajacent to a transmission wire by measuring the angle of Faraday rotation of a laser beam in a flint glass rod. The laser beam is transmitted and analyzed at a ground potential site, and in the energized part this device has neither insulated conductors nor active elements. An experimental laser current transformer yielded a sensitivity of 66 mV per 100 A and good linearity. Various sources of error and modifications are discussed.     

Immobilized fluorescent cyclodextrin on a cellulose membrane as a chemosensor for molecule detection

Dansylglycine-modified cyclodextrin (DnsC4-beta-CD) was prepared as a fluorescent host that is capable of being immobilized on a cellulose membrane (DnsC4-beta-CD membrane). DnsC4-beta-CD immobilized on the cellulose membrane decreased its fluorescence intensity with increasing concentration of guest molecules, indicating that the host changes the location of the dansyl group from inside to outside the cyclodextrin cavity upon guest accommodation, which is similar to DnsC4-beta-CD in solution; thereby, the DnsC4-beta-CD membrane is useful as a novel chemosensor for detecting molecules. This result demonstrates that the cellulose membrane is useful as a practical supporting material for various chromophore-modified cyclodextrins.     

Fluorescent cyclodextrin immobilized on a cellulose membrane as a chemosensor system for detecting molecules

Dansyl glutamate-modified cyclodextrin (DnsGlu-beta-CD) was prepared as a fluorescent host, which is capable of being immobilized on a cellulose membrane (DnsGlu-beta-CD-membrane). The fluorescence intensity of DnsGlu-beta-CD decreased with increasing concentration of guest molecules, indicating that the host changes the location of the dansyl group from inside to outside the cyclodextrin cavity upon guest accommodation. Similar guest-induced decrease in the fluorescence intensity was observed for DnsGlu-beta-CD immobilized to a cellulose membrane. This result demonstrates that the cellulose membrane may be used as a practical supporting material of various chromophore-modified cyclodextrins and that DnsGlu-beta-CD-membrane is useful as a novel disposable chemosensor for molecules.     

Evaluation of the Wear Energy Consumption of Nitrogenated Diamond-Like Carbon Against Alumina

The wear energy consumption of nitrogenated diamond-like carbon (NDLC) in the tribo-test against alumina was evaluated. The energy input induced by the power source of the tribometer is applied to the contact area of two sliding bodies. The energy is dissipated into the two bodies with various transforming energies, such as (1) wear energy, (2) friction heat, (3) strain energy, (4) plastic deformation energy, and (5) chemical reaction energy used to form the tribo-layer. Determining the breakdown of the energy consumption into each mode is notably important for the investigation of the tribological mechanism. The surface fracture energy of NDLCs was evaluated by the micro-indentation method. The newly created surface area was estimated using the wear particles size distribution measured by image processing. The consumed wear energy was obtained by the surface fracture energy multiplied by the new created surface area corresponding to the generation of the wear particles in the tribo-test. The index numbers of the wear consumption energy/energy input ratio of the NDLCs were almost the same as those of their wear coefficients.