Plasma polymerization of trimethylsilane in cascade arc discharge

Plasma polymerization of trimethylsilane (TMS) in cascade arc discharge was experimentally investigated. It was found that the deposition rates of methane and TMS plasma polymer were dependent on plasma parameters, and the surface characteristics of plasma polymer were also dependent on plasma variables. The following plasma variables were studied: arc current, argon flow rate, TMS flow rate, chamber pressure, substrate axial, and radial positions. Carbon, silicon, and oxygen were the main elements observed in TMS polymer films obtained by x-ray photoelectron spectroscopy (XPS). Powder-like TMS polymer films were observed by scanning electron microscopy (SEM). The size distribution of the powder-like particles was strongly dependent on deposition parameters. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1653–1665, 1997     

Studies on pool boiling heat transfer: Macrolayer thickness in transition boiling

Macrolayer thicknesses in transition boiling were determined from the energy balance relation q_tr = ρ_lH_fgδ_l·f , based on measurements of q_tr (the time-averaged heat flux in transition boiling) and f (the detachment frequency of vapor masses) for water and ethanol boiling on vertical and horizontal 15-mm-diameter surfaces under atmospheric pressure. The macrolayer thickness for the vertical surface, designed to prevent liquid contact with the periphery of the surface during the vapor mass hovering, agreed well with the correlation proposed previously by the present authors, when the heat flux at macrolayer formation is obtained from a nucleate boiling curve extrapolated to the superheat of transition boiling. The macrolayer on the horizontal surface was apparently thickened due to the inflow of bulk liquid beneath the growing vapor masses. © 1999 Scripta Technica, Heat Trans Jpn Res, 27(8): 568–583, 1998     

Morphological change in FePt nanogranular thin films induced by swift heavy ion irradiation

We have investigated morphology change of FePt nanogranular films (FePt)₄₇(Al₂O₃)₅₃ under irradiation with 210 MeV Xe ions. Here, electron tomography technique was extensively employed to clarify three-dimensional (3D) structure in irradiated specimens, in addition to conventional transmission electron microscopy (TEM) techniques such as bright-field observation and scanning TEM energy dispersive X-ray spectroscopy (STEM-EDX) analysis. The ion irradiation induces the coarsening of FePt nanoparticles with elongation along the beam direction. Electron tomography 3D reconstructed images clearly demonstrated that when the fluence achieves 5.0 × 10¹⁴ ions/cm², well-coarsened FePt balls have been formed on the irradiated surface, and the particles in the film interior have been deformed into rods along the ion trajectory. The alloy particles become inhomogeneous in composition after prolonged irradiation up to 1.0 × 10¹⁵ Xe ions/cm². The particle center is enriched with Pt, while Fe is slightly redistributed to the periphery.     

Plasma treatment of polymeric fibers for improved performance in cement matrices

The surfaces of collated fibrillated polypropylene fibers and monofilament polyolefin fibers were treated by low‐temperature cascade arc plasma with different gases to study the effect of interface treatment on the mechanical performance and toughening in fiber‐reinforced concrete composites. Results from static flexural tests conducted in a four‐point configuration on 17 concrete mixes including one unreinforced control mix, 4 mixes with untreated fibers (two volume contents for each of two fiber types—fibrillated and monofilament), and 12 mixes with plasma‐treated fibers (two volume contents, above two fiber types, and three plasma treatments) are presented and discussed. It is concluded that plasma treatment of polymeric fibers is effective in improving the flexural performance and toughness of fiber reinforced concrete composites. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1985–1996, 2000     

Growth of yttria stabilized zirconia thin films by metallo-organic, ultrasonic spray pyrolysis

Randomly and preferentially oriented thin films of yttria stabilized zirconia (YSZ) have been prepared on fused quartz substrates by ultrasonic spray pyrolysis using zirconium octylate and yttrium octylate as metallo-organic precursors at a substrate temperature of 873–1023 K. The as-deposited films composed of fine columnar grains were found to be crystalline and transparent with a cubic fluorite structure. With increasing substrate temperature the growth rate and diameter of the columnar grains increased and the crystal habit showed a preferential orientation at the (111) plane.     

Highly Manufacturable and Reliable HfSiON N-FET With Poly-Si/a-Si Stacked Gate for LSTP Applications

We have proposed a novel poly-Si/a-Si/HfSiON transistor to enhance reliabilities without performance degradation for a 65-nm-node low standby power (LSTP) application. By insertion of a thin amorphous-Si layer between the Poly-Si gate electrode and HfSiON, both phosphorus penetration from gate electrode and a reaction at gate electrode/HfSiON interface are successfully suppressed, so that positive bias temperature instability, one of the biggest issues for high-k gate dielectric, is drastically improved by two orders of magnitude. By carefully optimizing the gate stack structure of HfSiON, the HfSiON device can satisfy both lower gate leakage and gate-induced drain leakage at the same time. As a result, an excellent I_on- I_standby (= I_g + l_off) characteristic can be achieved, compared to the conventional SiON device. The a-Si insertion technique can realize the combination between the high-k gate dielectric and Poly-Si for future LSTP applications.     

Dietary PlsEtn Ameliorates Colon Mucosa Inflammatory Stress and ACF in DMH-Induced Colon Carcinogenesis Mice: Protective Role of Vinyl Ether Linkage

Ethanolamine plasmalogen (PlsEtn), a sub-class of ethanolamine glycerophospholipids (EtnGpl), is a universal phospholipid in mammalian membranes. Several researchers are interested in the relationship between colon carcinogenesis and colon PlsEtn levels. Here, we evaluated the functional role of dietary purified EtnGpl from the ascidian muscle (87.3 mol% PlsEtn in EtnGpl) and porcine liver (7.2 mol% PlsEtn in EtnGpl) in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in vivo, and elucidated the possible underlying mechanisms behind it. Dietary EtnGpl-suppressed DMH-induced aberrant crypt with one foci (AC1) and total ACF formation (P < 0.05). ACF suppression by dietary ascidian muscle EtnGpl was higher compared with dietary porcine liver EtnGpl. Additionally, dietary EtnGpl decreased DMH-induced oxidative damage, overproduction of TNF-α, and expression of apoptosis-related proteins in the colon mucosa. The effect of dietary ascidian muscle EtnGpl showed superiority compared with dietary porcine liver EtnGpl. Our results demonstrate the mechanisms by which dietary PlsEtn suppress ACF formation and apoptosis. Dietary PlsEtn attained this suppression by reducing colon inflammation and oxidative stress hence a reduction in DMH-induced intestinal impairment. These findings provide new insights about the functional role of dietary PlsEtn during colon carcinogenesis.     

Lattice distortion of porous Si by Li absorption using two-dimensional photoelectron diffraction

Lithiation and delithiation of porous silicon were studied using reflection high energy electron diffraction (RHEED), two-dimensional photoelectron diffraction, and a stereo atom-scope, which is realized by the combination of a display-type spherical mirror analyzer and circularly polarized soft X-ray. A nanosized porous silicon layer was prepared by electrochemical etching of p-type silicon (001) wafer in ethanolic solutions containing hydrofluoric acid. The morphology of the as-grown porous silicon as observed using SEM was filled with about 9 nm holes. This porous silicon also retains the crystallographic orientation of the wafer from which it was etched and is optically active with visible photoluminescence. The measured RHEED pattern and 2π steradian Si 2p photoelectron diffraction pattern from Si (001) surface showed an increase in lattice constant by lithiation, and that change in lattice constant was restored to its original values by delithiation.