Effects of Mn content and texture on fatigue properties of as-cast and extruded AZ61 magnesium alloys

Fatigue behavior of as-cast and extruded AZ61 magnesium alloys in ambient air (20 °C–55%RH) was investigated. It was found that size and distribution of cast defect influenced tensile and fatigue performance of the as-cast alloy. Fatigue limit of the as-cast alloy was significantly low compared to the extruded alloy. The casting defects served as stress concentration sites for fatigue crack nucleation. Fatigue tests were also carried out on a high Mn content alloy. All of the specimens failed from an inclusion near the specimen surface. Fatigue limit of Mg alloy with high Mn content was lower compared to that of the low Mn content alloy. Further, investigation on the effect of texture on fatigue and fatigue crack growth behavior of the extruded AZ61 magnesium alloy plate was carried out. The results showed that fatigue strength in the longitudinal direction to the extruded direction was higher compared to those in the transverse and 45° directions. Significant effect of specimen orientation on fatigue crack growth behavior for both short and long cracks was found near the threshold region. However, regardless of specimen orientation, the da/dN–ΔK_eff curves for all three kinds of specimens were in a narrow band. It is suggested that the difference in the fatigue life among the specimen orientations will be mainly due to the difference in the crack closure behavior. A transition of fracture mechanism was found for a long crack. Slip fracture mechanism was dominant above the transition point, whereas below the transition point, slip fracture mechanism was associated with cleavage fracture.     

Transfer technology using inorganic separation layer and apparatus for fabricating flexible OLED displays

We established a fabrication process of flexible displays, adopting a transfer technology using an inorganic tungsten‐separation‐layer. Our separation process requires physical force and water. Tungsten oxide over tungsten in the separation layer plays a key role in separation: water injection into the tungsten oxide reduces the force necessary for separation. In this study, we describe the apparatus we built for the fabrication process of flexible displays. This apparatus fabricated an 8k (7680 × 4320 effective pixels) flexible organic light‐emitting diode display.     

Enzymatic enrichment of astaxanthin from <Emphasis Type="Italic">Haematococcus pluvialis</Emphasis> cell extracts

An industrially available preparation of astaxanthin (Ax) from Haematococcus pluvialis contained 41.6 wt% acylglycerols and 24.9 wt% FFA in addition to 14.6 wt% Ax, which was a mixture of free and FA ester forms (free Ax/Ax monoesters/Ax diesters=4.9∶80.3∶14.8, by mol). Enrichment of Ax by a two-step process was attempted. The first step was hydrolysis of acylglycerols with Candida rugosa lipase: A mixture of 1.0 kg H. pluvialis cell extracts, 1.0 L water, and 50 U/g-reaction mixture of the lipase was agitated at 30°C for 42 h. The degree of hydrolysis of acylglycerols reached 94.4%, but Ax esters were not hydrolyzed. Removal of FFA from the resulting oil layer by molecular distillation enriched the content of Ax esters to 40.8 wt5 (named Ax40). The second step was enzymatic conversion of Ax esters to free Ax, which successfully proceeded in the presence of ethanol (EtOH). When a mixture of 50.0 g Ax40, 8.2 g EtOH (5 molar equiv. against FA), 58.2 mL water, and 1500 U/g-mixture of Pseudomonas aeruginosa lipase was stirred at 30°C for 68 h, the free Ax content increased to 89.3 mol%. Free Ax was efficiently recovered by precipitation with n-hexane. The purity of Ax was thereby raised to 70.2 wt% with a 63.9% overall recovery of the initial content in the cell extracts.     

Kinetic factors in the chemical and electrochemical reactions including hydrogen on the first transition metals and cu-ni alloys

The relationships between catalytic activities (the rate of reaction of H₂-D₂ exchange, hydrogen evolution, hydrogen recombination, and para-hydrogen conversion), behaviour of hydrogen adsorption (amount of adsorbed hydrogen and initial heat of adsorption), and electronic properties of metals (work function, the percentage of the d-character and density of states at the Fermi level) are discussed. The catalytic activities were related to the amount of the strongly adsorbed hydrogen, which was estimated to be bounded by the 3d-band but not holes in the 3d-band in metals or alloys.     

Bending of poly(vinyl alcohol)–poly(sodium acrylate) composite hydrogel in electric fields

Bending of poly(vinyl alcohol) hydrogel mixed with poly(sodium acrylate) chains, PVA–PAA gel, under the influence of dc electric fields was studied. The PVA–PAA gel was prepared by repeatedly freezing and thawing a mixture of PVA and polyacrylic acid aqueous solutions. The PVA–PAA gel was a hydrogel with the PAA chains, which were entangled with the PVA polymer network and were fixed in the gel. The PVA–PAA gel bent toward the negative electrode in electrolyte solutions under dc electric fields as did the polyelectrolyte gel with negatively charged polyions. The PVA gel, free of PAA, was insensitive to dc electric fields. The deflection of the bending and the bending speed were influenced by the filed intensity, the concentration of the polyion in the gel, and the thickness of the gel. The bending of the PVA–PAA gel was qualitatively explained by a bending theory of polyelectrolyte gel, based upon the change of the osmotic pressure due to the ion concentration difference between the inside and the outside of the gel.     

Zwitterions of 1-poly(oxyethylene)-2-imidazoline derivatives as anti-electrostatic agent for polyamide fiber

Summary This paper describes a group of anti-electrostatic agents 1 for polyamide fiber(Nylon 6). Agents 1 are calcium imidazolinium-carboxylates having poly(oxyethylene) chain and long alkyl group (C₁₁H₂₃ and C₁₇H₃₅). Eight derivatives of 1 were prepared by a four-step one-pot synthesis shown in Scheme 1. Nylon 6 fibers and films containing some of 1 (1.0 and 2.0 wt%) show improved anti-electrostatic property. The performance of 1 was increased by the increase of the length of poly(oxyethylene) chain.     

A 513‐ppi FFS‐mode LCD using technique for changing part of active layer of oxide semiconductor to transparent electrode

We have established a technique for changing part of an active layer of an oxide semiconductor (OS) to a transparent electrode in order to achieve an aperture ratio of 50% or higher and a bezel width of 1 mm in an fringe field switching (FFS) mode LCD panel with a high resolution of 513 ppi. Furthermore, we have prototyped an LCD panel by examining a driving mode that enables low‐frequency driving.     

Plant Growth Inhibition By <Emphasis Type="Italic">Cis</Emphasis>-Cinnamoyl Glucosides and <Emphasis Type="Italic">Cis</Emphasis>-Cinnamic Acid

Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl--_d-glucopyranose (CG) and 6-O-(4-hydroxy-2-methylene-butyroyl)-1-O-cis-cinnamoyl--_d-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)-2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC₅₀ values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC₅₀ value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields.     

Microstructure and Thermal Properties of Polylactides with Different L‐ and D‐Unit Sequences: Importance of the Helical Nature of the L‐Sequenced Segments

A series of polylactides (PLA) with different stereo sequences are prepared by the copolymerization of L ‐lactide and DL ‐lactide. It is confirmed that the glass transition temperature (T_g) of the PLA decreases with decreasing optical purity of the lactate units (%ee) according to the Fox's equation. Analysis of the FT‐IR spectra of these PLA samples reveals that the absorbance at 1 265 cm^?1 (δCH + νCOC) decreases with increasing L ‐content while the absorbance at 1 210 cm^?1 (ν_asCOC + r_asCH₃) increases with increasing L ‐content. These changes in absorbance are reasonably correlated with the randomness and helical nature of the L ‐sequenced segments involved in PLA. Namely, the PLA chains with higher L ‐content comprise a higher number of short helical blocks that are made of several L ‐lactate units. This difference in helical nature causes the opposite dependences of T_g and density on the L ‐content of PLA; i.e., the increased T_g and decreased density with increasing L ‐content.

FT‐IR spectra of a PDLLA film, NO‐PLLA, and BO‐PLLA.     

Latest developments for “system‐on‐glass” displays using low‐temperature poly‐Si TFTs

Abstract— A 2.3‐in.‐diagonal QVGA‐formatted “System‐On‐Glass” display has been developed by using low‐temperature poly‐Si TFT‐LCD technology. This display fully integrates 6‐bit RGB digital interface drivers as well as all the power supply circuitry to drive the LCD, which requires neither external driver ICs nor power‐supply ICs. This paper discusses the newly developed TFT circuit technologies used in this LCD. The development trend of the “System‐On‐Glass” display is also reviewed.