A Physics-Based Crystallographic Modeling Framework for Describing the Thermal Creep Behavior of Fe-Cr Alloys

In this work, a physics-based thermal creep model is developed based on the understanding of the microstructure in Fe-Cr alloys. This model is associated with a transition state theory-based framework that considers the distribution of internal stresses at sub-material point level. The thermally activated dislocation glide and climb mechanisms are coupled in the obstacle-bypass processes for both dislocation and precipitate-type barriers. A kinetic law is proposed to track the dislocation densities evolution in the subgrain interior and in the cell wall. The predicted results show that this model, embedded in the visco-plastic self-consistent framework, captures well the creep behaviors for primary and steady-state stages under various loading conditions. The roles of the mechanisms involved are also discussed.

     

Energy transfer between lead sulfide quantum dots in the liquid phase

Förster resonant energy transfer (FRET) from smaller sized PbS Quantum Dots (QDs) to larger sized ones occurs in the liquid phase when adjacent QDs are brought in close proximity by the bridging action of the two SH groups in aromatic or aliphatic dithiols. Signatures of FRET were observed by the lowering of the fluorescence peak corresponding to the smaller particle group and intensification of the peak corresponding to the larger particle group in a mixture of the two in the liquid phase. The suspensions of the two QDs size distributions were mixed in a ratio such that total surface area of the smaller QDs was equal to that of the larger QDs. A 10–13% size deviation in each PbS QDs group also allows this phenomenon to be observed in these samples and is manifested by red-shift and broadening of the fluorescence peak. The ratio of the absorption peak intensity corresponding to the two groups of PbS QDs in the mixture remains the same.     

A novel shape-based coding-decoding technique for an industrial visual inspection system

This paper describes a unique single camera-based dimension storage method for image-based measurement. The system has been designed and implemented in one of the integrated steel plants of India. The purpose of the system is to encode the frontal cross-sectional area of an ingot. The encoded data will be stored in a database to facilitate the future manufacturing diagnostic process. The compression efficiency and reconstruction error of the lossy encoding technique have been reported and found to be quite encouraging.     

Reliability evaluation of multistage interconnection networks with multi-state elements

This paper presents a graph-theoretic method for the reliability evaluation of multistage interconnection networks with multistate elements. For the purpose of analysis, the generalized cube (GC), a unique-path MIN and an extra-stage cube (ESC), a fault-tolerant variation of GC, are considered. An algorithm is presented to evaluate three reliability measures, i.e. terminal reliability (TR), broadcast reliability (BR) and network reliability (NR) of MINs for different reliability values of links and switches. The proposed method is found to be simple and computationally efficient compared to the existing techniques, and therefore can be applied for reliability evaluation of other large interconnection networks used in parallel computing systems.     

Broadband scalable model for Si‐RF on‐chip spiral inductors with substrate eddy current effect

A new broadband scalable compact model for on‐chip spiral inductor is presented. It includes a substrate network and a high resistive component to accurately capture the substrate eddy current effect, skin and proximity effects at high frequencies. The proposed model shows a good match with the measurement results over a frequency range of up to 20 GHz. An automated parameter extraction and optimization procedure has been developed using equivalent circuit analysis and particle swarm optimization. We achieved good scalability for all model parameters with respect to spiral layout geometry. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.