Mechanical properties and microstructure of centrifugally compacted alumina and hot-isostatically-pressed alumina

High purity alumina powder was compacted under a high centrifugal force. Mechanical properties of the sintered body were studied by the three-point bending test at room temperature and by the compressive test at elevated temperatures. Comparison was made with hot-isostatically-pressed (HIP) alumina. The room-temperature flexural strength of the centrifugally compacted (CC) alumina was found to be 1330 MPa compared with 585 MPa of the HIP alumina. The difference in the room-temperature strength was attributed to the presence of the amorphous phase along the grain boundaries of the HIP alumina caused by the segregation of carbon and sulfur during HIP. A large ductility was observed above 1473 K in the CC alumina and above 1573 K in the HIP alumina. High-temperature ductility was lost in the HIP alumina at 1773 K where the amorphous grain-boundary phase was considered to be melted.     

In-situ observations on interphase boundary migration and grain growth during α/γ phase transformation in iron-4.2%Cr alloy

In-situ observations on interphase boundary migration and grain growth during α/γ phase transformation in iron-4.2%Cr alloy@渡边忠雄$日本东北大学 @OBARA Kouichi$Laboratory of Materials Design and Interface Engineering, Department of Nanomechanics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan @TSUREKAWA Sadahiro$Laboratory of Materials Design and Interface Engineering, Department of Nanomechanics, Graduate School of Engineering, Tohoku Univer…     

How should Prolog computation Be represented for practical use?

We propose a visual computation model called theBox and Plane Model (BPM), which visually clarifies the semantics of backtracking, the cut operator, and side-effects, thus allowing the procedural features of Prolog to be grasped. On the bases of the BPM, we developed a visual debugger for Prolog, PROEDIT2, which has proved that this kind of pragmatic computation model for Prolog increases the efficiency of the debugging work.     

Optimum policy of one-unit system with two types of maintenance and minimal repair

This paper deals with a one-unit system with minimal repair. Two policies (new Policy IV and Policy IV′) are considered. Under these policies, the Laplace transform of the point-wise availability and the stationary availability of the system are obtained using not the renewal theory but the supplementary variable method. And under new Policy IV, the optimum policy in the sense of the availability is discussed.     

A procedure to determine intersections between polyhedral objects

The procedure described here employs face-to-face intersection analysis to determine whether two or more polyhedral objects intersect. As means to minimize the number of pairs of faces which should be examined for face-to-face intersection analysis, a solution box approach, mutual divisibility, and visibility of two faces are considered. Intersection detection between two faces is done by the determination of their parity mode.This work was supported in part by the Department of Computer Science at the University of Illinois at Urbana-Champaign, Urbana, Illinois; the National Science Foundation under NSF Grant GJ-328.     

Long-term characteristics of XLPE cables

To study the long-term characteristics of XLPE cables installed in free air and in water, aging tests were conducted under various testing conditions using XLPE cables with both 3.5 mm and 6 mm insulation. From the Weibull plots of lifetime distribution under the voltage stress E_L as the minimum breakdown strength, the minimum value of time to breakdown t_L under the constant voltage was estimated. The results of accelerated aging tests of XLPE cables installed in free air demonstrated that the V-t characteristics of XLPE cables could not be described by the conventional inverse power law (t ∝ V⁻ⁿ) with a single constant life exponent n. Based on the microscopic observation of a sliced insulation removed from XLPE cables, it was concluded that bow-tie trees with longer tree length observed in cables tested in water were caused by the moisture from outside, whereas the trees in cables tested in free air were caused by the residual moisture originally existing in the insulation. The breakdown strength of the aged cables tested in water increases through cable drying. However, it does not recover to the original values.     

Computational image sensor for on sensor compression

We propose a novel integration of image compression and sensing in order to enhance the performance of an image sensor. By integrating a compression function onto the sensor focal plane, the image signal to be read out from the sensor is significantly reduced and the pixel rate of the sensor ran consequently be increased. The potential applications of the proposed sensor are in high pixel-rate imaging, such as high frame-rate image sensing and high-resolution image sensing. The compression scheme we employ is a conditional replenishment, which detects and encodes moving areas. In this paper, we introduce two architectures for on-sensor compression; one is the pixel parallel approach and the other is the column parallel approach. We prototyped a VLSI chip of the proposed sensor based on the pixel parallel architecture. We show the design and describe the results of the experiments obtained by the prototype chip     

Influence of alkyldiacrylate side‐chains on electro‐optical properties in liquid crystal/composite films

In order to realize a paper‐like display using polymer‐network liquid‐crystal (PNLC) films, an increase in backscattering intensity is required. The morphology of the films, and the molecular interactions between the liquid crystals and polymers forming the polymer network, both play an important role in determining film electro‐optical properties such as the driving voltage and the reflectance. We have analyzed several factors related to the morphology of the films. Aiming at a reduction in the driving voltage, the effects of alkyl side‐chains in diacrylates have been investigated. Based on the results, we successfully produced a prototype paper‐like display.     

Senescence marker protein-30 (SMP30) rescues cell death by enhancing plasma membrane Ca(2+)-pumping activity in Hep G2 cells

The microwave spectra of the four isotopomers of the BrBO molecule (79Br10BO, 81Br10BO, 79Br11BO, and 81Br11BO) were observed in a dc glow discharge plasma of a mixture of boron tribromide vapor and oxygen gas. Rotational transitions of BrBO were measured for the ground state as well as for the vibrationally excited states, nu2 (bend) and nu3 (Br-B str.), for all of four isotopomers, and associated 2nu2, nu2 + nu3, and 2nu3 for the 11B species. The l = 0 substate of the 2nu2 state interacts with the nu3 state through the Fermi resonance. The rotational constants determined for the ground states of the four isotopomers yield the substitution structure, rs(Br&sbond;B) = 1.835791(70) ? and rs(B&dbond;O) = 1.20472(25) ?. The pi character and ionic character of the Br-B bond, which are estimated from the bromine quadrupole coupling constant eQq, are discussed through the comparison with those of related molecules such as BrCN and BrBS. Copyright 1998 Academic Press.