Surface accuracy measurement of a deployable mesh reflector byplanar near-field scanning

Using a near-field antenna measurement facility, it is possible to simultaneously evaluate the surface accuracy of a reflector antenna as well as the far-field pattern of the antenna for a short time. The surface errors of a 2-m deployable mesh reflector for satellite use were measured by a planar near-field system. As a result, the influence of periodic structures, due to the antenna ribs, is clearly observed. Also, the surface accuracy obtained with the near field scanning technique coincides well with that obtained by an optical measurement technique     

A cellular automaton model of particle motions and its applications

A natural object such as a flame with smoke is featured in terms of ambiguous boundaries and complex motion. One way of modeling natural objects is by particle systems, which need a large amount of computation time to calculate interactions among the particles. This paper deseribes another way of modeling particle motions based on a cellular automaton. Cellular automata are massively parallel computation models that can simulate complex phenomena. In our model, particle motions are simulated in a cellular space with a Margolus neighborhood, which has good conservation properties and collision detectability. This paper shows several applications in two-dimensional cellular space.     

Effects of high field generation of charge trapping in the oxideand interface traps on MOS capacitors and MOSFETs

Oxide charge trapping and interface state generation phenomena under the various high-field stress conditions have been investigated using capacitors fabricated on both p-and n-type substrates, and p- and n-channel MOSFETs. It was found that prediction based on MOSFET devices yielded shorter lifetimes than predictions based on capacitors     

Molecular dynamics simulation of deformation behavior in amorphous polymer: nucleation of chain entanglements and network structure under uniaxial tension

In order to clarify the mechanical behavior of molecular chains in amorphous polymers, a molecular dynamics simulation is conducted on a nanoscopic specimen of amorphous polyethylene under uniaxial tension. The specimen involves 3542 random coil molecular chains composed of 500–1500 methylene monomers with about two million methylene groups. The stress–strain curve shows a linear elastic relationship at the initial stage of _zz0.03 at . Then the material “yields” by elongating without stress increase up to the strain of 1.5, where strain hardening appears. Careful investigation of changes in dihedral angle and morphology of all molecular chains reveals that the gauche→trans transition takes place during yielding, generating a new network-like structure composed of entangled molecular clusters and oriented chains bridging them. The strain hardening is due to the directional orientation and stretching of molecular chains between entanglements in the nucleated structure.     

Dispersion of ceramic powders into particulate superplastic Al-Li alloy

A new method for dispersing homogeneously fine ceramic powders into a particulate alloy matrix has been developed. The Al-Li matrix alloy, with controlled crystal grain size and shape, shows superplastic behaviour under certain conditions. The homogeneous dispersion of SiC in the matrix alloy was achieved by introducing the fine particles of filler along the grain boundaries within the alloy particles. This new compounding method yields a composite powder (i.e. each particle itself is a composite) rather than a mixture of different components.     

Design of a new cationic amphiphile with efficient DNA-transfection ability

Several double-chain ammonium amphiphiles were designed to have physicochemical properties, such as membrane fluidity and aggregate morphology, suitable for DNA transfection, according to our previous results (1, 2). Potency of the amphiphiles during the transfer of plasmid DNA into COS cells was examined. Of the amphiphiles tested, O,O'-ditetradecanolyl-N-(trimethylammonio acetyl)diethanolamine chloride (14Dea2) had the highest transfection activity. Optimal conditions for transfection of COS cells by 14Dea2 were also determined.     

Comparative studies on immune responses to infection in susceptible B10.BR mice infected with different strains of the murine nematode parasite Trichuris muris

A comparison of immune responses to infection between groups of B10.BR mice infected with different strains of T. muris, S strain (isolated in Sobreda, Portugal), E strain (isolated in Edinburgh), and E-J strain (originally E strain, which has been maintained in our laboratory, Japan), was performed. In mice infected with E and E-J strains, most of the worms were expelled by day 32 after infection, though the expulsion was faster in E-J strain-infected mice. In contrast, no expulsion was observed in S strain-infected mice by day 32 and egg production occurred on day 32. IL-4 production occurred in concanavalin A (Con-A)-stimulated mesenteric lymph node cells (MLNC) from B10.BR mice infected with E and E-J strains, whereas no IL-4 production was observed in S strain-infected mice. IL-4 production did not occur in normal mice. In comparison with normal mice, high levels of IFN-gamma production by Con A-stimulated MLNC were detected in mice infected with every strain of T. muris. IFN-gamma production in S strain-infected mice was greater, occurred earlier and was more persistent than in mice infected with E and E-J strains. IgG1 and IgG2a antibodies to T. muris excretory/ secretory antigens were observed in B10.BR mice infected with every strain of T. muris. Antibody production showed similar kinetics. These differences in the expulsion kinetics and IL-4 production in B10.BR mice infected with S, E, and E-J strains suggest the involvement of IL-4 in protection against T. muris infection, and confirm the previous conclusion by Else et al.     

Growth of the high reflectivity Bi2O3 glass films by atmospheric pressure halide CVD

We reported the results of an investigation into the preparation of amorphous Bi₂O₃ onto borosilicate glass substrate by means of atmospheric pressure halide chemical vapor deposition using BiI₃ and oxygen as a source materials. Obtained thin films lower than 475 °C was amorphous and it was almost transparent in infrared region. But the amorphous films are iodine-containing Bi₂O₃, as results of analysis by XRD and XPS.     

The major pathways of protein translocation across membranes

Nine low molecular weight nerve growth factor (NGF)-like peptides have been designed to mimic the putative receptor-binding epitope of NGF defined by two beta-hairpin loops. Eight different spacers were used as variable links between the beta-loop amino acid residues, which from mutagenesis experiments were found to play an important role in the biological activity of NGF. These spacers were amino acids, natural or non-natural, differing in length (5-13 A) and polarity. The peptides were synthesized via the Fmoc solid-phase peptide synthesis and purified by reversed-phase HPLC. Their primary sequences were analyzed by a combination of automated Edman degradation and mass spectrometry. The peptides were tested using two different biological assays, the fibre outgrowth from chick embryonic sympathetic ganglia and the PC12 cell differentiation assay. Weak antagonistic effects could be observed for some peptides.