Control of wetting on Ti-based bulk metallic glass surfaces by a hydrothermal method

The surfaces of the Ti-based bulk metallic glasses (Ti₅₀Ni₂₀Cu₂₅Sn₅) were modified by a hydrothermal method using sodium hydroxide (NaOH) solution, and the surface wettability was investigated. No reflections were observed in the XRD patterns of the NaOH-treated samples even though there was a clear change of the color, indicating formation of amorphous oxide phases. The Raman spectra showed peaks attributed to sodium titanate compounds (Na–O–Ti) and titanium oxide. Some of the samples were observed to have a very rough surface microstructure such as a “house-of-cards” or leaf-like structure. The water contact angle of the treated samples decreased with increasing treatment temperature and time. These results indicate that the wettability of the sample surface was able to be controlled from hydrophobic to hydrophilic by changing the conditions of the hydrothermal treatment.     

Dissolution and Separation of Ruthenium in Borosilicate Glass

The behavior of ruthenium oxide (RuO₂) in aluminoborosilicate glass used for the stabilization of nuclear waste was investigated. It was found that 0.025 mass% RuO₂ dissolved as Ru⁴⁺ in the glass at 1400°C, which caused the glass to turn yellow. When the RuO₂ amount was 0.05 mass%, needle-shaped crystals formed in the glass during slow cooling. If the added amount exceeded 0.1 mass% and the cooling rate was slow, it separated rapidly and the glass became pale after cooling. No dissolution of ruthenium was detectable after melting at 1200°C.     

Preparation of plasma-polymerized membranes from fluoroalkyl acrylates and methacrylates and gas permeability through the membranes

Summary Plasma-polymerized membranes were prepared from fluoroalkyl acrylates and methacrylates by two different directions of monomer injection and the permeation rates of O₂ and n₂ through the membranes were investigated. The chemical structure and composition of the plasmapolymerized membranes varied significantly by the direction of monomer injection. The optimum plasma conditions to yield maximum gas separation characteristics was obtained by the remote plasma excitation at the W/FM value of 20 J/mg, where W is the discharge power, F is the monomer flow rate and M is the molecular weight of the monomer.     

High-Speed TDM–WDM Techniques for Long-Haul Submarine Optical Amplifier Systems

Optical amplifier techniques have led to the installation of large-capacity submarine systems and further capacity increases seem likely. This paper reviews the FSA submarine system, which flexibly operates at both 2.5 and 10 Gb/s and offers maximum transmission capacity of 60 Gb/s for commercial use. The system configuration as well as its characteristics and upgradability will be introduced, including measurement results on time-division-multiplexing/wavelength-division-multiplexing (TDM–WDM) transmission at bit rates of 10 and 20 Gb/s using non-return-to-zero or soliton pulses. To further increase transmission capacity, TDM–WDM techniques that permit more than 10 Gb/s signal transmission in each data channel should be developed. Thus, pulse formats, which include non-return-to-zero, return-to-zero, or soliton pulses, and dispersion allocation in transmission fibers are significant issues. We introduce and discuss our recent results from high-speed (10 to 40 Gb/s) TDM–WDM signal transmission experiments with regard to the above aspects.     

Structural analysis of β-form poly(p-xylyene) starting from a high-resolution image

The crystal structure of β-form poly(p-xylylene) is analysed starting from a high-resolution image of a single crystal of this polymer. The high-resolution image corresponding to the projection of molecules onto the ab-plane along the chain axis shows clearly the mutual position of each molecule in a unit cell. The molecules are aligned wavily in the direction along the a-axis and the rough positions of their centres in a unit cell can be determined from the image. The refinement of the structure is carried out by the usual least-squares method using the intensities of electron and X-ray diffractions. The space group of the β-form is trigonal, P3, and the lattice dimensions are a=2.052 nm, c=0.655 nm and γ=120°. The unit cell contains 16 molecules and one of them is considered to occupy statistically one of three equivalent orientations so as to satisfy the P3 symmetry.     

Apology as aggression control: Its role in mediating appraisal of and response to harm.

Two studies examined the effects of an apology on a victim's aggression and explored the psychological mechanisms underlying such effects. In Study 1, female undergraduates were psychologically harmed and then received an apology by another female student. In Study 2, male undergraduates were asked to role play a victim in a hypothetical harm situation. Results indicate that when the harm-doers apologized, as opposed to when they did not, the victim-subjects refrained from severe aggression against them. Regression analyses suggested that such aggression-inhibitory effects of an apology were mediated by impression improvement, emotional mitigation, and reduction in desire for an apology within the victims. It was also found that when the harm was severe, such effects of an apology on aggression were attenuated. The more severe the harm is, the more extensive of an apology may be needed to alleviate the victim's anger and aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conformational properties of the guanine-binding site of ribonuclease T1 inferred from the X-ray structure and protein engineering

Recognition by ribonuclease T₁ of guanine bases via multidentatehydrogen bonding and stacking interactions appears to be mediatedmainly by a short peptide segment formed by one stretch of aheptapeptide, Tyr⁴²-Asn⁴³-Asn⁴⁴-Tyr⁴⁵-Gly⁴⁶-Gly⁴⁷-Phe⁴⁸. Thesegment displays a unique folding of the polypeptide chain—consistingof a reverse turn, Asn⁴⁴-Tyr⁴⁵-Glu⁴⁶-Gly⁴⁷, stabilized by ahydrogen-bond network involving the side chain of Asn⁴⁴, themain-chain atoms of Asn⁴⁴, Gly⁴⁷ and Phe⁴⁸ and one water molecule.The segment is connected to the C terminus of a ß-strandand expands into a loop region between Asn⁴³ and Ser⁵⁴. Lowvalues for the crystallographic thermal parameters of the segmentindicate that the structure has a rigidity comparable to thatof a ß-pleated sheet. Replacement of Asn⁴⁴ with alanineleads to a far lower enzymatic activity and demonstrates thatthe side chain of Asn⁴⁴ plays a key role in polypeptide foldingin addition to a role in maintaining the segment structure.Substitution of Asn⁴³ by alanine to remove a weak hydrogen bondto the guanine base destabilized the transition state of thecomplex by 6.3 kJ/mol at 37°C. In contrast, mutation ofGlu⁴⁶ to alanine to remove a strong hydrogen bond to the guaninebase caused a destabilization of the complex by 14.0 kJ/mol.A double-mutant enzyme with substitutions of Asn⁴³ by a histidineand Asn⁴⁴ by an aspartic acid, to reproduce the natural substitutionsfound in ribonuclease M_s, showed an activity and base specificitysimilar to that of the wild-type ribonuclease M_s. The segmenttherefore appears to be well conserved in several fungal ribonucleases.     

Human placenta gangliosides

Gangliosides extracted from human placenta were composed of four major components (G1–G4), which were purified by silica beads column chromatography. The structures of these gangliosides were analyzed by exoglycosidase treatments, 400 MHz proton magnetic resonance spectroscopy and gas chromatography-mass spectrometry and were concluded to be as follows: Gangliosides containing more than 10 sugar residues were observed in addition to the above four major components. But ganglio-series gngliosides were undetectable in the placenta.     

Terahertz paintmeter for noncontact monitoring of thickness and drying progress in paint film

We propose a paintmeter for noncontact and remote monitoring of the thickness and drying progress of a paint film based on the time-of-flight measurement of the echo signal of a terahertz (THz) electromagnetic pulse. The proposed method is effectively applied to two-dimensional mapping of the painting thickness distribution for single-layer and multilayer paint films. Furthermore, adequate parameters for the drying progress are extracted from the THz pulse-echo signal and effectively applied to monitor the wet-to-dry transformation. The THz paintmeter can be a powerful tool for quality control of the paint film on the in-process monitoring of car body painting.