The influence of titanium dioxide on the rheological and extrusion properties of polymer melts

An experimental study of the influence of titanium dioxide (TiO₂) on the rheological and extrusion properties of five polymer melts (two low-density polyethylenes, two high-density polyethylenes, and a polystyrene) has been carried out. Increasing TiO₂ loading increases the shear viscosity η, with the extent of increase being greater at lower shear rates. At moderate and high TiO₂ loadings, the filled melts may possess yield values. Empirical equations relating viscosity to filler loading have been developed. The first normal stress difference was measured for the melts and found to increase with increasing TiO₂ loading. However, the extent of increase was less than found for the viscosity function and interpretation in terms of the theory of viscoelasticity suggests that the characteristic relaxation time of the melts decreases with increasing TiO₂ level. Empirical equations relating the first normal stress difference coefficient to volume fraction of the filler have been developed. Addition of TiO₂ is found to decrease extrudate swell and retard the occurrence of extrudate distortion.     

High-rate plating of aluminium from the bath containing aluminium chloride and lithium aluminium hydride in tetrahydrofuran

An electrolyte for the high-rate plating of aluminium from the tetrahydrofuran solutions of aluminium chloride and lithium aluminium hydride has been developed. A smooth and coherent deposit of aluminium has been obtained at the current density of 18 A dm^–2 without stirring, whereas the conventional diethyl ether solvent bath allows good plating up to 5 A dm^–2 under the same condition. The current densities applicable are increased with an increase in the molar fraction of aluminium chloride in tetrahydrofuran. The conductivity of the plating solution was measured at various molar ratios of aluminium chloride to lithium aluminium hydride. A plateau region of the conductivity curve plotted against the molar ratio is consistent with the composition of the plating bath giving a good plating. The plateau region is enlarged with an increase in total aluminium concentration.     

High‐contrast driving method for advanced CEL structure with magnesium oxide single‐crystal powder in ACPDP

Abstract— A new driving method for an advanced‐CEL‐structure panel has been developed. Picture qualities have been upgraded. Discharge time lags are drastically shortened by priming electron emission from magnesium oxide (MgO) single‐crystal powder, refered to as a crystal emissive layer (CEL). The advanced‐CEL‐structure panel has CEL material on the surface of not only the surface‐discharge‐electrode side but also on the address‐electrode side. This panel structure enables a stable opposed discharge when the address electrode functions as a cathode. By utilizing the opposed discharges in the reset and LSB‐SF sustain periods, the dark‐room contrast ratio has been drastically increased to over 20,000:1, which is higher than five times that of the conventional method, and the luminance of the least‐significant‐bit sub‐field (LSB‐SF) is as low as 0.1 cd/m², which is one‐fourth that of the conventional method. The high‐picture‐quality PDP TVs refered to as “KURO” that employs these technologies have been introduced into the marketplace.     

Identification and functional analysis of genes required for desulfurization of alkyl dibenzothiophenes of Mycobacterium sp. G3

Mycobacterium sp. G3 was reported as a dibenzothiophene (DBT)-degrading microorganism and the first strain to have the ability to degrade high-molecular-weight alkyl DBTs, such as 4,6-dibutyl DBT and 4,6-dipentyl DBT, by the C-S bond cleavage pathway. Three genes (mdsA, mdsB, and mdsC) for desulfurization, which form a cluster, were cloned from Mycobacterium sp. G3. The expression of each gene in Escherichia coli JM109 showed that MdsC oxidized DBT to DBT sulfone, MdsA transformed DBT sulfone into 2-(2'-hydroxyphenyl)benzene sulfinate (HPBS), and MdsB desulfinated HPBS into 2-hydroxybiphenyl (HBP), indicating that the gene products of mdsABC are functional in the recombinant. MdsC oxidized 4,6-dimethyl DBT, 4,6-diethyl DBT, 4,6-dipropyl DBT and 4,6-dibutyl DBT to each sulfone form, suggesting that MdsC covers a broad specificity for alkyl DBTs.     

Planar InP/InGaAs-APD with a guardring formed by Cd diffusion through SiO2

A graded junction, with a breakdown voltage twice as high as that for an abrupt junction, was formed in n-InP by Cd diffusion through SiO2 film. Planar-type InP/InGaAs-APDs with this graded junction for a guardring showed a uniform multiplication gain over the whole sensitive area with no local breakdown. Cd diffusion through SiO2 was revealed to be very useful for formation of the guardring.     

Fullerene-C60 incorporated in liposome exerts persistent hydroxyl radical-scavenging activity and cytoprotection in UVA/B-irradiated keratinocytes

The aim of this study is to examine antioxidant activity of fullerene-C60 (C60) incorporated in liposome (LpsmFlln, a diameter of 75.6 nm). LpsmFlln is water-soluble, and composed of hydrogenated lecithin of 89.7%, glycine soja sterol of 10% and C60 of 0.3%. Hydroxyl radicals (*OH), generated from UVA- or UVB-irradiated H2O2, were scavenged by LpsmFlln but not by C60-lacking Lpsm as assessed by ESR, showing that the active principle is C60 as scanty as 1/415 weight versus LpsmFlln; the *OH amount (% of non-additive control) was decreased, LpsmFlln-dose-dependently, and for 0.5% LpsmFlln (C60-eq.:16.7 microM) to 34.1% or 78.3% upon irradiation with UVA (12 J/cm2) or UVB (500 mJ/cm2), respectively, showing the superiority for UVA to UVB in terms of the *OH scavenging of LpsmFlln. Cell viability of human skin keratinocytes HaCaT decreased to 41.1% upon UVA-irradiation at 10 J/cm2, but retained to 60.6% with 0.025% LpsmFlln (C60-eq.: 0.84 microM) together with prevention of cell-morphological degeneration, in contrast to scarce effects of C60-lacking Lpsm. The scavenging activity for Fenton reaction-generated *OH, detected by DMPO/ESR, was 96.2% or 72.2% (% of no-additive control) at 1 min and decreased time-dependently to 24.8% or 28.3% at 12 min with 16.7 microM L-ascorbic acid (Asc) or Trolox, respectively, whereas 0.5% LpsmFlln (C60-eq:16.7 microM, the same concentration as for Asc) diminished *OH by 90.9% at 1 min and 91.5% even at 12 min, demonstrating the superiority of LpsmFlln to Asc or Trolox in terms of persistence of *OH-scavenging ability. Repressive efficacy on beta-carotene discoloration (% of control) for 60 min was in the order, based on the same molar or weight concentration: 1.3%:3.34 microM Asc < 25.0%:0.1% Lpsm < 36.3%:0.1% LpsmFlln (C60-eq.:3.34 microM) < 57.2%:3.34 microM Trolox, indicating the preventive effect of LpsmFlln against beta-carotene oxidation. Thus, LpsmFlln was demonstrated for an antioxidant ability characteristic of long-term persistence, and is attributed to fullerene-C60 but scarcely to Lpsm in all the tests examined, and is expected as the skin-protecting agent against oxidative stress.