A possibility for developing high strength soft magnetic materials in FeCo-X alloys

The effects of the combination of cold rolling and heat treatment upon mechanical and magnetic properties have been examined for the FeCo-based alloys with additive elements such as carbon, vanadium, chromium, molybdenum, tungsten, tantalum, niobium, and nickel. It is revealed that whenever alloys including such elements are subjected to cold rolling the yield strength can be raised to between 100 and 200 kg mm^–2, and that cold rolling is effective in both strengthening and in improving soft magnetic properties, even when cold rolling is followed by annealing or ageing. This suggests that these alloys can be used for lessening the weight of parts which are used as soft magnetic materials, although their properties will depend on the combinations of cold rolling and heat treatments, and/or on the added elements and the control of their amount.     

High-pressure atom transfer radical polymerization of methyl methacrylate for well-defined ultrahigh molecular-weight polymers

The feasibility of high-pressure atom transfer radical polymerization (ATRP) for synthesizing well-defined polymers of extraordinarily high molecular weights was demonstrated. ATRP of methyl methacrylate (MMA) under pressures up to 500 MPa was investigated at 60 °C. The addition of a small amount of a Cu(II)Cl₂/ligand complex along with the general benefits of high pressure of enhancing propagation and suppressing termination brought about an excellent control of polymerization even with an extremely low concentration of ATRP initiator. For example, there was produced PMMA with a number-average molecular weight M_n of 3.6 × 10⁶ and a polydispersity index of 1.24, which had never been achieved by conventional ATRP.     

Numerical evaluation of pile group effect of a composite group

Pile group effects of a composite pile group that consists of a group of subgroups are investigated based on a series of static pushover analysis with the help of the nonlinear three-dimensional finite element method (FEM). The numerical result suggests that there is an interaction between subgroups as well as an interaction within each subgroup; the former interaction effect is very similar to the latter if the distance between subgroups is normalized with respect to an equivalent pile diameter of each subgroup. A simplified method to estimate pile group effects of a composite pile group is then proposed in which the interaction effects within and between the subgroups are both accounted for using the same P-multiplier approach commonly employed for a pile group. The P-multipliers estimated by the proposed method show a fairly good agreement with those estimated from the FEM analyses.     

A study of a fire on a diesel railcar

A fire broke out on a diesel railcar while running on a line of the Japan Railways Group. After an exhaustive investigation into the cause of the fire, it was found that the origin had been the lubricating oil of the engine. The lubricating oil vaporized from a long idling engine while the car was standing and accumulated in the exhaust silencer in considerable amounts. When the car was climbing up a long slope, the oil was exposed to a high-temperature exhaust gas and ignited. The flame attacked and melted the exhaust funnel, and eventually caused a fire.     

Preparation of 1,4-bis(4-methylstyryl)benzene nanocrystals by a wet process and evaluation of their optical properties

Single-crystal 1,4-bis(4-methylstyryl)benzene is a promising material for optoelectronic device applications. We demonstrate the preparation of 1,4-bis(4-methylstyryl)benzene nanocrystals by a wet process using a bottom-up reprecipitation technique. Scanning electron microscopy revealed the morphology of the nanocrystals to be sphere-like with an average particle size of about 60 nm. An aqueous dispersion of the nanocrystals was monodisperse and stable with a ζ-potential of -41 mV. The peak wavelengths of the absorption and emission spectra of the nanocrystal dispersion were blue and red shifted, respectively, compared with those of tetrahydrofuran solution. Powder X-ray diffraction analysis confirmed the crystallinity of the nanocrystals. The presented 1,4-bis(4-methylstyryl)benzene nanocrystals are expected to be a candidate for a new class of optoelectronic material.     

Analysis of current density and specific absorption rate in biological tissue surrounding transcutaneous transformer for an artificial heart

This paper reports on the current density and specific absorption rate (SAR) analysis of biological tissue surrounding an air-core transcutaneous transformer for an artificial heart. The electromagnetic field in the biological tissue is analyzed by the transmission line modeling method, and the current density and SAR as a function of frequency, output voltage, output power, and coil dimension are calculated. The biological tissue of the model has three layers including the skin, fat, and muscle. The results of simulation analysis show SARs to be very small at any given transmission conditions, about 2-14 mW/kg, compared to the basic restrictions of the International Commission on nonionizing radiation protection (ICNIRP; 2 W/kg), while the current density divided by the ICNIRP's basic restrictions gets smaller as the frequency rises and the output voltage falls. It is possible to transfer energy below the ICNIRP's basic restrictions when the frequency is over 250 kHz and the output voltage is under 24 V. Also, the parts of the biological tissue that maximized the current density differ by frequencies; in the low frequency is muscle and in the high frequency is skin. The boundary is in the vicinity of the frequency 600-1000 kHz.     

Embryoid body culture of mouse embryonic stem cells using microwell and micropatterned chips

The proliferation and differentiation properties of embryoid bodies (EB) from mouse embryonic stem (ES) cells were compared under two microchip conditions: microwell chip and micropatterned chip. The microwell chip contained 270 microwells (diameter, 600 μm; depth, 600 μm) on a polymethylmethacrylate plate and was surface-modified with polyethylene glycol (PEG) to render it non-adhesive. The micropatterned chip contained 270 gelatin spots (diameter, 200 μm) as the cell adhesion area on a glass plate; the region lacking these spots was PEG-modified to render it non-adhesive. The ES cells spontaneously formed the EBs from cell aggregates in each microwell in the chip. In contrast, cells inoculated onto the patterned chip formed a monolayer on the gelatin spots and gradually proliferated to form EBs. The EBs in the patterned chip maintained the high cell growth rate and the expression of endoderm (TTR and AFP) and mesoderm (Nkx2.5, αMHC, Flk1, and PDGFRβ) markers was increased, and these cell properties were similar to the previous methods (hanging drop and round-bottomed 96-well plate cultures). In contrast, the proliferation of ES cells in the microwell chip was lower than in the patterned chip and previous methods, and the EB differentiation proceeded slowly and only formed a small amount of endoderm. These results indicate that the difference of EB generating process in the microchip cultures may affect to the proliferation and differentiation of ES cells, and the existence of microwell structure in the microchip downregulates the cell proliferation and the differentiated progress of ES cells.     

Use of fine-grained shredder dust as a cement admixture after a melting, rapid-cooling and pulverizing process

Shredder dust is a residue, which is removed from valuable ferrous metals found in scrap automobile and electronic waste. It is also an industrial waste byproduct which, under legislation in place since April 1996, must be disposed of in landfill sites. One method of disposing shredder dust is by scorification, however, this is a costly process and therefore impractical. Costs could be reduced if the shredder dust had a valuable use, and, in this paper, the authors examine its effectiveness as a cement admixture.

First, molten shredder dust was crushed for use as a cement admixture. However, it was difficult to crush it completely because metallic grains were mixed in with molten shredder dust. These particles were removed by sifting and the molten shredder dust was crushed once again. Eventually, a fine 75 μm and less powder type of slag was obtained. This slag was mixed with Ordinary Portland Cement (OPC) to form a cement mortar and subsequently a mortar test was conducted. From the test results, it was found that the long-term strength of the cement did not deteriorate even when it included 30% by weight of the pulverized molten shredder dust.