The reactivity and stability of the edge faces of swelling clay minerals can be altered by layer charge and the stacking structure; however, these effects are poorly understood due to experimental limitations. The structure and stability of the montmorillonite {110}, {010}, {100}, and {130} edge faces with a layer charge of either y = 0.50 or y = 0.33 (e−/Si4O10) were investigated using first-principles calculations based on density functional theory. Stacked- and single-layer models were tested and compared to understand the effect of stacking on the stability of montmorillonite edge faces. Most stacked layers stabilize the edge faces by creating hydrogen bonds between the layers; therefore, the surface energy of the layers in the stacked-layer model is lower than in the single-layer model. This indicates that the estimates of edge face surface energy should consider the swelling conditions. Negative surface energies were calculated for these edge faces in the presence of chemisorbed water molecules. A high layer charge of 0.50 reduced the surface energy relative to that of the low layer charge of 0.33. The isomorphic substitution of Mg for Al increased the stability of interlayer Na ion positions, which were stable in the trigonal ring next to the Mg ions. The lowest surface energies of the {010} and {130} edge faces were characterized by the presence of Mg ions on edge faces, which had a strong cation adsorption site due to the local negative charge of the edges. The coordination numbers of O atoms around cations adsorbed to these edge faces were small in comparison to interlayers without water.

In order to study magnetic states in Fe-hydride under pressure, X-ray magnetic circular dichroism (XMCD) at the Fe K-edge has been measured up to 27.5 GPa. As a result, hydrogenation from bcc-Fe to dhcp-FeH occurs within a narrow region of 3.2-3.8 GPa, which is clearly observed by the dichroic profile in dhcp-FeH differing from that in bcc-Fe. Influence of H atoms on Fe 3d and 4p electronic states is discussed using the pressure-dependent XMCD and the first-principles calculation.

The relationship between the fluctuating velocity vector and the temperature fluctuation has been examined using direct numerical simulation databases of a turbulent channel flow with passive scalar transport using a constant time-averaged heat flux at each wall for h+ = 180, 395, 640 and 1020 (where h is the channel half-width with the superscript denoting normalization by wall variables) at Prandtl number Pr=0.71. The analogy between spectra corresponding to the kinetic energy and scalar variance is reasonable in both inner and outer regions irrespective of whether the spectra are plotted in terms of kx or kz, the wavenumbers in the streamwise and spanwise directions respectively. Whereas all three velocity fluctuations contribute to the energy spectrum when kx is used, the longitudinal velocity fluctuation is the major contributor when kz is used. The quality of the analogy in the spectral domain is confirmed by visualizations in physical space and reflects differences between spatial organizations in the velocity and scalar fields. The similarity between the spectra corresponding to the enstrophy and scalar dissipation rate is not as good as that between the kinetic energy and scalar variance, emphasizing the prominence of the scalar sheets as the centre of the channel is approached. The ratio R between the characteristic time scales of the velocity and scalar fluctuations is approximately constant over a major part of the channel and independent of h+, when the latter is sufficiently large. This constancy, which is not observed in quantities such as the turbulent Prandtl number, follows from the spectral similarities discussed in this paper and has implications for turbulent heat transport models.

Direct numerical simulations of a turbulent channel flow with passive scalar transport are used to examine the relationship between small-scale velocity and scalar fields. The Reynolds number based on the friction velocity and the channel half-width is equal to 180, 395 and 640, and the molecular Prandtl number is 0.71. The focus is on the interrelationship between the components of the vorticity vector and those of the scalar derivative vector. Near the wall, there is close similarity between different components of the two vectors due to the almost perfect correspondence between the momentum and thermal streaks. With increasing distance from the wall, the magnitudes of the correlations become smaller but remain non-negligible everywhere in the channel owing to the presence of internal shear and scalar layers in the inner region and the backs of the large-scale motions in the outer region. The topology of the scalar dissipation rate, which is important for small-scale scalar mixing, is shown to be associated with the organized structures. The most preferential orientation of the scalar dissipation rate is the direction of the mean strain rate near the wall and that of the fluctuating compressive strain rate in the outer region. The latter region has many characteristics in common with several turbulent flows; viz. the dominant structures are sheetlike in form and better correlated with the energy dissipation rate than the enstrophy.

Calcium phosphate films were prepared on commercially pure titanium (CP-Ti) substrates by RF magnetron sputtering using β-tricalcium phosphate targets. XRD and FTIR analyses showed that the films consisted of amorphous calcium phosphate and oxyapatite phases. The (002) preferred orientation of the oxyapatite phase was observed depending on the oxygen gas concentration in the sputtering gas. The surface reactions of the calcium phosphate films were investigated in Hanks' solution and PBS(-). Apatite crystallites were detected on the films after immersion for 7 days. An active surface reaction was observed on the amorphous calcium phosphate films during immersion in PBS(-). The CP-Ti plates coated with the calcium phosphate films were placed on the mandible of male Japanese white rabbits. These results suggest that the calcium phosphate coating improves the biocompatibility of titanium implants with bone.

Silkworm (Lepidoptera) males produce dimorphic sperm: nucleate eupyrene sperm and anucleate apyrene sperm. The eupyrene sperm are ordinary sperm to fertilise the eggs, while the function of apyrene sperm remains uncertain. After meiosis, 256 sperm cells are enclosed by a layer of cyst cells, forming a sperm bundle. We have previously documented that the nucleus of eupyrene sperm anchors to the head cyst cell, which locates at the anterior apex of the bundle, by an acrosome tubule-basal body assembly. Neither the basal body attachment to the nucleus nor the acrosome is seen in apyrene sperm, and the nuclei remain in the middle region of the bundle. Peristaltic squeezing starts from the anterior of the bundles in both types of sperm, and cytoplasmic debris of the eupyrene sperm, and both the nuclei and debris of apyrene sperm, are eliminated at the final stage of spermatogenesis. Since the irregularity of meiotic division in apyrene sperm is known, we used triploid silkworm males that show irregular meiotic division even in eupyrene spermatocytes and are highly sterile. The irregular nuclei of the triploid are discarded by the peristaltic squeezing just as those of the apyrene sperm. Transmission electron microscopic observations disclose the abnormality in the acrosome tubule and in the connection to the basal body. The peristaltic squeezing of sperm bundles in the silkworm appears to be the final control mechanism to eliminate irregular nuclei before they enter female reproductive organs.

The effects of noble metal elements such as ruthenium, rhodium and palladium on the viscosity and electrical resistivity of simulated nuclear waste glass were studied. The glass enriched with noble metals showed the viscosity of a non-Newtonian fluid. The viscosity of the waste glass with 10 wt% Ru0 2 was 3 to 7 times higher than that of glass without noble metals. The RuO2 was mainly responsible for the increase in viscosity for the glass enriched with noble metals. Electrical resistivity of the glass with 15 wt% RuO2 was one seventh to two orders of magnitude lower than that of glass without noble metals. The three noble metals contributed to the decrease in resistivity. The quantitative effects of noble metals on these properties were obtained.

Effects of residual phosphorus in the channel region of amorphous silicon thin film transistors(a-Si TFTs) on the TFT characteristics were quantitatively investigated. Concentration and the depth profile of the residual phosphorus were measured by high resolution secondary ion mass spectroscopy(SIMS). The OFF characteristics of a-Si TFTs were also measured.

The SIMS data showed that the phosphorus exists about 100nm deep into intrinsic a-Si(i-a-Si), but the OFF characteristics showed that the activity of the residual phosphorus is 4 order of magnitude lower than that of heavily phosphorus doped a-Si(+-a-Si). The residual phosphorus is found to be inactive and stable, and has little effect on a-Si TFT characteristics.

These results enabled us to fabricate inverted staggered a-Si TFTs by the simplest process using only 2 photo-mask steps and 1 self-aligned exposure.