THERMAL RESIDUAL STRESSES IN FILAMENT-WOUND CARBON-FIBER-REINFORCED COMPOSITES

Explicit algebraic expressions are first proposed to predict easily and precisely the thermal-expansion coefficients of unidirectional reinforced plastics. They are given as functions of the thermal and elastic properties of the constituent materials and of the fiber-volume fraction. They are derived by considering circular anisotropic fibers arranged in a hexagonal array in a matrix. Then, analytical expressions are derived for the thermal-expansion coefficients and curing stresses in filament-wound laminated composites under the assumption of elastic behavior and within the framework of laminated plate theory.

Experiments on carbon-fiber/epoxy composite cylinders reinforced by helical and circumferential windings show good agreement with the calculated values. The residual stresses induced by curing are found not to be negligible compared with the low tensile strength transverse to the fibers. Such algebraic expressions for thermal coefficients, together with those for elastic moduli and failure criterion proposed by one of the authors, seem to be of use in the tailored design of laminated composite structures in a closed form, which elucidate the effects of various sorts of constitutive parameters.     

Large-particle movement and drag coefficient in a fluidized bed

Flow visualization studies of the behavior of a large particle in a fluidized bed were conducted using neutron radiography. The large particle moved according to the bed materials, especially in the wake of a bubble. When the density of the large particle was high, the particle moved with a velocity different from that of a bubble, and in some cases the particle moved downward through a bubble. When the density was low enough, the particle moved on the surface of the bubble wake. The drag force of the large particle immersed in a fluidized bed was measured. The drag force increased with an increase in the volumetric gas flux as well as with an increase in the particle diameter. The drag coefficient was derived and was well correlated on the basis of a two-phase model and experimentally determined effective viscosity of the bed materials. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 26 (1): 54–67, 1997     

Inhibitory effect of aqueous spinach extract on degranulation of RBL-2H3 cells

The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500 Da to 14 kDa. The extract inhibited elevation of the intracellular Ca²⁺ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation.     

A 52-week feeding study of genetically modified soybeans in F344 rats

A chronic feeding study to evaluate the safety of the genetically modified glyphosate-tolerant soybeans (GM soybeans) was conducted using rats. F344 DuCrj rats were fed diet containing GM soybeans or Non-GM soybeans at the concentration of 30% in basal diet. Non-GM soybeans were closely related strain of GM soybeans. These two diets were adjusted to an identical nutrient level. In this study, the influence of GM soybeans on rats was compared with that of the Non-GM soybeans, and furthermore, to assess the effect of soybeans themselves, the groups of rats fed GM and Non-GM soybeans were compared with a group fed commercial diet (CE-2). General conditions were observed daily and body weight and food consumption were recorded. At the intermediate examination (26 weeks), and at the termination (52 weeks), animals were subjected to hematology, serum biochemistry, and pathological examination. There were several differences in animal growth, food intake, serum biochemical parameters and histological findings between the rats fed the GM and/or Non-GM soybeans and the rats fed CE-2. However, body weight and food intake were similar for the rats fed the GM and Non-GM soybeans. Gross necropsy findings, hematological and serum biochemical parameters, organ weights, and pathological findings showed no meaningful difference between rats fed the GM and Non-GM soybeans. These results indicate that long-term intake of GM soybeans at the level of 30% in diet has no apparent adverse effect in rats.     

Quantitative analyses of the behavior of exogenously added bacteria during an acidulocomposting process

Poly[3-hydroxybutyrate-co-3-hydroxyvalerate(3HV)] was produced in recombinant Escherichia coli LS5218 from ruthenium-catalyzed cellulose hydrolysate and propionate. The strain was found to be resistant to 5-hydroxymethylfurfural (5-HMF), which is a major inhibitory byproduct generated in the cellulose hydrolysis reaction. The 3HV fraction was successfully regulated in the range of 5.6-40 mol%.     

Dry developable resist in e-beam and sr lithography

Dry developable resists comprised of poly(methyl isopropenyl ketone) (PMIPK) and 4-methyl-2,6-dI-(4′-azldoben-zylidene)-cyclohexanone-1 gave excellent results in SK lithography, i. e., high aspect ratio resist patterns with vertical walls were easily obtained by maskless dry etching in the single layer resist process. Because of the simplicity of single layer resist processing and the high etch rate in maskless dry etching for the formation of thick resist patterns, the dry developable resist in SR lithography may be advantageous to the multilayer resist for the purpose of generating high resolution, thick resist patterns with vertical walls. The resolution limit of the dry developable resist which reproduces the designed dimensions was 100 nm line and 200 nm space when a conventional e-beam apparatus was used at 20 KV in the dry developable multilayer resist process.     

Fundamental study of the development of a transformer with low‐viscosity silicone liquid

Silicone liquid is less flammable and produces less environmental pollution compared with mineral oil. Applicability of 20‐cSt silicone liquid to transformers was investigated from the viewpoints of insulation, cooling performance, and the less‐flammability evaluation. The results showed that the basic characteristics of 20‐cSt silicone liquid were verified in application to a less‐flammable transformer. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(2): 21–28, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20483     

新型50A和75A／600V压注模封装IPM

介绍了额定值为50 A/600 V和75 A/600 V的大型双列直插式智能功率模块(第4代DIPIPMTM),该产品是三菱电机针对柜式变频空调和工业变频驱动应用而开发的。它采用第5代全栅型CSTBTTM硅片、小型化IC和新型导热绝缘膜等多项新技术。