Simulation of Strength Distribution in Ground Ceramics by Incorporating Residual Stress Effect

Strength of ground ceramics may be affected by residual stress as well as surface flaws induced by grinding. Strength prediction for ground ceramics is convenient for mechanical design of ceramic components. In this article, a numerical procedure based on fracture mechanics was proposed to estimate strength distribution of ground ceramics by considering grinding-induced residual stress. Bending strength and residual stress of ground ceramics were measured for three grinding-conditions. By comparison of simulated results with experimental ones, it was revealed that strength characteristics in experiments were well simulated by using the proposed procedure.     

Transmittance and cathodoluminescence of AlN ceramics sintered with Ca3Al2O6 as sintering additive

Aluminum nitride ceramics were prepared by sintering with 0–4.8 mass% of Ca₃Al₂O₆ (C₃A) as a sintering additive. The transmittance in the range of 260–550 nm increased with increasing amount of C₃A. The cathodoluminescence intensity attributed to oxygen-induced defects decreased with increasing amount of C₃A. From the results, the increase of the transmittance in the range of 260–550 nm was considered to be related to the decrease of the oxygen-induced defect density.     

Pulsed KrF excimer laser annealing of silicon solar cell

The pulsed KrF excimer laser annealing of silicon films for solar cell with EBEP-CVD and LP-CVD was studied theoretically and experimentally. Three-dimensional thermal diffusion equation for microcrystalline and amorphous silicon was solved by using the finite difference methods. The results of our heat-flow simulation of laser re-crystallization in a laser irradiation with 50 ns pulse duration almost agree with the experimental results in re-crystallization depth of 0.7 μm for microcrystalline silicon (EBEP-CVD) and 0.4 μm for amorphous silicon (LP-CVD) in a single pulse excimer laser annealing.     

Augmentation by phthalimides of phorbol ester-induced expression of tumor necrosis factor alpha message

N(alpha)-Phthalimidoglutarimide (thalidomide), 2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (PP-33) and its 4,5,6,7-tetrafluoro derivative (FPP-33) augmented 12-O-tetradecanoylphorbol 13-acetate-induced production by human leukemia HL-60 cells of both tumor necrosis factor alpha (TNF-alpha) mRNA and secreted TNF-alpha protein. Intracellular TNF-alpha protein production was increased to a lesser extent.     

Extracellular matrix of opacified anterior capsule after endocapsular cataract surgery

BACKGROUND: We determined the types and distribution of glycosaminoglycans (GAGs) and collagens, in anterior capsular opacification after endocapsular phacoemulsification and aspiration (ECPEA) and intraocular lens implantation. METHODS: Opacified anterior capsules were removed from human eyes after ECPEA. Immunohistochemical staining was performed to determine GAGs with monoclonal antibodies to chondroitin, chondroitin-4-sulfate (C4S), chondroitin-6-sulfate (C6S), dermatan sulfate (DS), and keratan sulfate (KS); collagens with monoclonal antibodies to types I, II, and III collagens; and cellular characteristics with monoclonal antibodies to vimentin, desmin, alpha-smooth muscle actin, and cytokeratin. Decorin mRNA and type I collagen mRNA were detected by in situ hybridization. RESULTS: In the capsules, the C6S, DS, KS, and types I and III collagens were similar to the chemical components found at the adhesion site of the anterior and posterior capsules after extracapsular cataract extraction, and cellular components contained vimentin, desmin, alpha-smooth muscle actin, cytokeratin, decorin mRNA, and type I collagen mRNA. CONCLUSIONS: The GAGs and collagens in opacified anterior capsule after ECPEA were similar to those found during wound healing, although KS is present in normal anterior segment tissue during development and only in the cornea postnatally. These chemical components may be produced by myofibroblast-like cells presumably transformed from lens epithelial cells.     

High performance 35 nm gate length CMOS with NO oxynitride gate dielectric and Ni salicide

The 35 nm gate length CMOS devices with oxynitride gate dielectric and Ni salicide have been fabricated to study the feasibility of higher performance operation. Nitrogen concentration in gate oxynitride was optimized to reduce gate current I/sub g/ and to prevent boron penetration in the pFET. The thermal budget in the middle of the line (MOL) process was reduced enough to realize shallower junction depth in the S/D extension regions and to suppress gate poly-Si depletion. Finally, the current drives of 676 /spl mu/A//spl mu/m in nFET and 272 /spl mu/A//spl mu/m in pFET at V/sub dd/=0.85 V (at I/sub off/=100 nA//spl mu/m) were achieved and they are the best values for 35 nm gate length CMOS reported to date.     

Gelsolin is a downstream effector of rac for fibroblast motility

Rac, a member of the rho family of GTPases, when activated transmits signals leading to actin-based membrane ruffling in fibroblasts. Compared with wild-type fibroblasts, gelsolin null (Gsn-) dermal fibroblasts have a markedly reduced ruffling response to serum or EGF stimulation, which signal through rac. Bradykinin-induced filopodial formation, attributable to activation of cdc42, is similar in both cell types. Wild-type fibroblasts exhibit typical lamellipodial extension during translational locomotion, whereas Gsn- cells move 50% slower using structures resembling filopodia. Multiple Gsn- tissues as well as Gsn- fibroblasts overexpress rac, but not cdc42 or rho, 5-fold. Re-expression of gelsolin in Gsn- fibroblasts by stable transfection or adenovirus reverts the ruffling response, translational motility and rac expression to normal. Rac migrates to the cell membrane following EGF stimulation in both cell types. Gelsolin is an essential effector of rac-mediated actin dynamics, acting downstream of rac recruitment to the membrane.     

Size exclusion behavior of polymers in amide solvents

Summary The size exclusion chromatography of neutral polymers and polymers containing ionic groups was investigated using N,N-dimethylacetamide (DMA) as mobile phase. As reported previously for N,N-dimethylformamide (DMF), acrylonitrile polymers containing charges, even those at terminal end groups, showed markedly small retention volumes and multimodal peaks by refractive index and 280 nm UV detectors. In DMA containing small amounts of LiBr the peaks of the ionic polymers were shifted to small retention volumes while neutral polymers with analogous chemical structures did not show the same behavior. As in the case of DMF the peculiarities observed in DMA were attributed to the formation of supramolecular structures by the interaction of the ionic groups in the polymer and the ionic species from DMA decomposition.     

Continual conversion of free fatty acid in rice bran oil to triacylglycerol by immobilized lipase

Rice bran oil containing 30–50% free fatty acid was continually converted to an oil containing more than 75% of triacylglycerol (TG) by means of immobilized lipase. The reaction was carried out at 60°C for 24 h with dehydration and reactant mixing by dry nitrogen flow under a positive nitrogen atmosphere. Enzymatic TG synthesis with evaporation by heating was not suitable because of the increasing peroxide value of the oil. Part of this article was presented at the annual meeting of the Japan Oil Chemists' Society at Sendai, Japan, October, 16, 1990.