There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Dual-phase (DP) steel is the flagship of advanced high-strength steels, which were the first among various candidate alloy systems to find application in weight-reduced automotive components. On the one hand, this is a metallurgical success story: Lean alloying and simple thermomechanical treatment enable use of less material to accomplish more performance while complying with demanding environmental and economic constraints. On the other hand, the enormous literature on DP steels demonstrates the immense complexity of microstructure physics in multiphase alloys: Roughly 50 years after the first reports on ferrite-martensite steels, there are still various open scientific questions. Fortunately, the last decades witnessed enormous advances in the development of enabling experimental and simulation techniques, significantly improving the understanding of DP steels. This review provides a detailed account of these improvements, focusing specifically on (a) microstructure evolution during processing, (b) exp...

An Overview of Dual-Phase Steels: Advances in Microstructure-Oriented Processing and Micromechanically Guided Design

Simultaneous capture removal of phosphate, ammonium and organic substances by MgO impregnated biochar and its potential use in swine wastewater treatment

Thermomechanical processing of advanced high strength steels

Grain Size Effect on Creep Properties of 304HCu SS and Modelling of Creep Curves Using Modified Theta Projection Approach

Bain variant dependent plastic anisotropy and formability in duplex stainless steels

In this report, we propose an experimental approach to determine the role of the epoxy-CNT interface on damping by designing two systems of composites which differ in the interfacial area. The composites are namely 'dispersed' and 'layered'. The CNTs were uniformly distributed in the epoxy matrix of the dispersed nanocomposites. Whereas, in the layered nanocomposite, a layer of CNT was sandwiched between two epoxy sheets. Image threshold technique was adopted to characterize the CNT spread area in the epoxy matrix. The epoxy-CNT interfacial area is assumed to be less than the CNT spread area due to the agglomeration of CNTs. The CNT spread area of dispersed nanocomposites was found to be 30 times higher than that of the layered composite. In addition to this, it is observed with microstructure analysis using scanning electron microscope and transmission electron microscope that the dispersed nanocomposites were comprised of more epoxy-CNT interfaces, and the layered nanocomposites have more CNT-CNT interfaces. At a particular CNT content, at the glass transition temperature, higher dynamic loss factor was characterized with dispersed nanocomposites. The energy dissipating nature of the epoxy-CNT and CNT-CNT interfaces were studied by analyzing the microstructural mechanisms of damping related to the system of composites dealt with this study.

Role of interface on damping characteristics of multi-walled carbon nanotube reinforced epoxy nanocomposites

Influence of phase morphology, static recrystallization, and crystallographic texture on room temperature tensile properties of Ti–6Al–4V alloy: Comparison between post-tested equiaxed, bimodal, and lamellar microstructures

S. Sankaran

Papers

Grain Size Effect on Creep Properties of 304HCu SS and Modelling of Creep Curves Using Modified Theta Projection Approach

Bain variant dependent plastic anisotropy and formability in duplex stainless steels

Grain Size Effect on Creep Properties of 304HCu SS and Modelling of Creep Curves Using Modified Theta Projection Approach

Role of interface on damping characteristics of multi-walled carbon nanotube reinforced epoxy nanocomposites

Influence of phase morphology, static recrystallization, and crystallographic texture on room temperature tensile properties of Ti–6Al–4V alloy: Comparison between post-tested equiaxed, bimodal, and lamellar microstructures