Implementation of a self-timed segmented bus

We propose an asynchronous structure for implementation on a SoC. An intersegment topological arrangement preserves parallelization and, through a so-called central arbiter, efficiently organizes communication with high signaling speed in the proposed structure. Researchers proposed the concept of segmenting buses primarily for multicomputer architectures. More recent approaches address on-chip implementation of segmented buses. We present an asynchronous segmented-bus architecture targeted for the modular design of high-performance SoC applications. The structure not only enables faster operation than a conventional bus system but also offers lower power consumption per transferred data item. This is possible because segmentation is realized in such a way that the majority of data transfers in the system are intrasegment transactions on relatively short wires with low or moderate capacitive loads.     

A Distributed State Estimator Utilizing Synchronized Phasor Measurements

With the creation of balancing authorities by the North American Reliability Council that span large portions of the North American interconnection, and stringent requirements for real time monitoring of power system evolution, faster and more accurate state estimation algorithms that can efficiently handle systems of very large sizes are needed in the present environment. This paper presents a distributed state estimation algorithm suitable for large-scale power systems. Synchronized phasor measurements are applied to aggregate the voltage phase angles of each decomposed subsystem in the distributed state estimation solution. The aggregated state estimation solution is obtained from the distributed solution using a sensitivity analysis based update at chosen boundary buses. Placement of synchronized phasor measurements in the decomposed subsystems is also investigated in this paper. Test results on the IEEE 118-bus test bed are provided     

Cooling and Solidification of Melted Drops in an Immiscible Cooling Medium

The cooling and solidification of melted drops during their movement in an immiscible cooling medium is widely employed for granulation in the chemical industry, and a study of these processes to provides a basis for the design of the granulation tower height and the temperature of the cooling medium is reported. A physical model of the cooling and solidification of the drop is established and the numerical calculation is performed. The influences of the key factors in the solidification, i.e., Bi number, drop diameter, temperature of the cooling medium, etc. are presented. The cooling and solidification during wax granulation in a water‐cooling tower and during urea granulation in an air‐cooling tower (spraying tower) are described in detail. Characteristics of the solidification and temperature distribution within the particle at different times are shown. The model and calculations can be used for structure design of the granulation tower and optimization of the operation parameters.     

Facile modifications of polyimide via chloromethylation: II. Synthesis and characterization of thermocurable transparent polyimide having methylene acrylate side groups

From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry     

Properties of nanoporous organosilicate hybrid thin films with a bimodal pore size distribution

Low dielectric poly[methylsilsesquioxane‐ran‐trifluoropropylsilsesquioxane‐ran‐(2,4,6,8‐tetramethyl‐2,4,6,8‐tetraethylenecyclotetrasiloxane)silsesquioxane]s {P[M‐ran‐TFP‐ran‐(TCS)]SSQs} having various compositions were synthesized using trifluoropropyl trimethoxysilane, methyl trimethoxysilane and 2,4,6,8‐tetramethyl‐2,4,6,8‐tetra(trimethoxysilylethyl)cyclotetrasiloxane. The chemical composition of the polymers and the content of SiOH end‐groups were controlled by adjusting the reaction conditions, and they were characterized by ¹H‐NMR. The thermally decomposable trifluoropropyl groups on the P[M‐ran‐TFP‐ran‐(TCS)]SSQ backbone and heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin (CD) were employed as pore generators. The dielectric constants of the porous CD/P[M‐ran‐TFP‐ran‐(TCS)]SSQ films were in the range 2.0–2.7 (at 100 kHz) depending on the concentration of the porogens, and showed no change over 4 days under aqueous conditions. The pore size of the films showed a bimodal distribution, with diameters of ca 0.5–1.0 nm for those originating from the trifluoropropyl groups and 1.7 nm from the CD. The elastic modulus and hardness of the 30 vol% CD‐blended film with a dielectric constant of 2.26 were 2.40 and 0.38 GPa, respectively, as determined by a nanoindenter. Copyright © 2005 Society of Chemical Industry     

Slow eroding biodegradable multiblock poloxamer copolymers

Biodegradable multiblock poloxamers (BMPs) with gel duration of 8 h to several weeks were prepared by varying their molecular weights from 4000 to 40 000 g mol^?1. The molecular weight of the BMP was controlled by changing the poloxamer to coupling agent ratio. Assuming a micelle packing model of the BMP gel, as in the case of a poloxamer gel, the micelle properties and critical gel concentration of BMPs were investigated on the basis of the scaling concept. The findings suggest that the control of molecular weight by hydrolyzable groups can be a facile approach to optimize the gel properties for biomedical applications. Copyright © 2005 Society of Chemical Industry     

Evaluation of ProKappa

ProKappa is an expert system tool kit developed by IntelliCorp in C using X-Windows for graphical interface. The SUN 3 or 4 version costs $9995/£7000 and $2595/£1800 for the interactive C environment.
This review covers ProKappa version 1.1, installed on a colour SUN SPARC Station 1 with the minimum recommended values of 12 Mb of memory and 30 Mb of swap space.
IntelliCorp can be contacted in the USA at 1975 El Camino Real West, Mountain View, CA 94040-2216 (+1 (415) 965-5500) and in the UK at 10 Jewry Street, Winchester, Hampshire SO23 8RZ (+44 (0)962 735348).     

Fractoemission from Lead Zirconate-Titanate

We present measurements of the electron, positive ion, and photon emission accompanying the fracture in vacuum of poly-crystalline 95/5 lead zirconate-titanate. The intensities of the charged-particle components of this fractoemission are shown to depend strongly on the direction (relative to the direction of fracture) and magnitude of polarization. The most intense emission is observed when the fracture surfaces are perpendicular to the polarization direction. The emission intensity increases monotonically with polarization. These results are interpreted in terms of a model involving charge separation on the fracture surfaces leading to a microdischarge during fracture. Implications to the interpretation of triboluminesence effects are discussed.     

Application of a multi-channel system for continuous monitoring and an early warning system.

A multi-channel continuous toxicity monitoring system developed in our laboratory, based on two-stage mini-bioreactors, was successfully implemented in the form of computer-based data acquisition. The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer, and uses genetically engineered bioluminescent bacteria for the detection of the potential toxicity from the soluble chemicals. This system can be stably and continuously operated due to the separation of the culture reactor from the test reactor and accomplish easy and long-term monitoring without system shut down by abrupt inflows of severe polluting chemicals. Four different recombinant bioluminescent bacteria were used in different channels so that the modes of the samples toxicities can be reasonably identified and evaluated based upon the response signature of each channel. The bioluminescent signatures were delivered from four channels by switching one at once, while the data is automatically logged to an IBM compatible computer. We also achieved the enhancement of the system through the manipulation of the dilution rate and the use of thermo-lux fusion strains. Finally, this system is now being implemented to a drinking water reservoir and river for remote sensing as an early warning system.     

Effect of grain boundaries on isothermal solidification during transient liquid phase brazing

The influence of liquid penetration at grain boundary regions on the rate of advance of the solid-liquid interface during isothermal solidification of transient liquid phase (TLP) brazed nickel joints has been examined. The test samples used in this study were Ohno-cast nickel with a grain size of >4 mm and a fine-grained nickel with a grain size of around 40 μm. Both Ni-base materials had the same chemical composition. The rate of isothermal solidification was greater when fine-grained nickel was employed during TLP brazing using Ni-11 wt pct P filler metal at 1200 °C. Liquid penetration at grain boundaries accelerates the isothermal solidification process by increasing the effective solid-liquid interfacial area and increasing the rate of solute diffusion into the base material. An analysis of electron channeling patterns has confirmed that random high-angle boundaries have a greater influence on the rate of isothermal solidification than ordered boundaries including small-angle or twin boundaries. Formerly Visiting Scientist, Department of Metallurgy and Materials Science, University of Toronto. Formerly Postdoctoral Fellow, Department of Metallurgy and Materials Science, University of Toronto