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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

How has Japan become a major economic power, a world leader in the automotive and electronics industries? What is the secret of their success? The consensus has been that, though the Japanese are not particularly innovative, they are exceptionally skilful at imitation, at improving products that already exist. But now two leading Japanese business experts, Ikujiro Nonaka and Hiro Takeuchi, turn this conventional wisdom on its head: Japanese firms are successful, they contend, precisely because they are innovative, because they create new knowledge and use it to produce successful products and technologies. Examining case studies drawn from such firms as Honda, Canon, Matsushita, NEC, 3M, GE, and the U.S. Marines, this book reveals how Japanese companies translate tacit to explicit knowledge and use it to produce new processes, products, and services.

The knowledge-creating company : how Japanese companies create the dynamics of innovation

Accelerating the discovery of advanced materials is essential for human welfare and sustainable, clean energy. In this paper, we introduce the Materials Project (www.materialsproject.org), a core program of the Materials Genome Initiative that uses high-throughput computing to uncover the properties of all known inorganic materials. This open dataset can be accessed through multiple channels for both interactive exploration and data mining. The Materials Project also seeks to create open-source platforms for developing robust, sophisticated materials analyses. Future efforts will enable users to perform ‘‘rapid-prototyping’’ of new materials in silico, and provide researchers with new avenues for cost-effective, data-driven materials design. © 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

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Commentary: The Materials Project: A materials genome approach to accelerating materials innovation

When metallic glasses (MGs) are subjected to mechanical loads, the plastic response of atoms is non-uniform. However, the extent and manner in which atomic environment signatures present in the undeformed structure determine this plastic heterogeneity remain elusive. Here, we demonstrate that novel site environment features that characterize interstice distributions around atoms combined with machine learning (ML) can reliably identify plastic sites in several Cu-Zr compositions. Using only quenched structural information as input, the ML-based plastic probability estimates ("quench-in softness" metric) can identify plastic sites that could activate at high strains, losing predictive power only upon the formation of shear bands. Moreover, we reveal that a quench-in softness model trained on a single composition and quenching rate substantially improves upon previous models in generalizing to different compositions and completely different MG systems (Ni62Nb38, Al90Sm10 and Fe80P20). Our work presents a general, data-centric framework that could potentially be used to address the structural origin of any site-specific property in MGs.

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A transferable machine-learning framework linking interstice distribution and plastic heterogeneity in metallic glasses

Light‐Harvesting Materials: New Light‐Harvesting Materials Using Accurate and Efficient Bandgap Calculations (Adv. Energy Mater. 2/2015)

Working longer:hours of work and health

The solid membrane of chromium ferricyanide in epoxy resin has been used as a silver sensitive electrode. The electrode response to silver ions is non-Nernstian, but a linear plot has been obtained in the concentration range 10−1-10−3M with a slope of 46 mV per decade of activity. The response time of the electrode is a few seconds and potentials generated are reproducible. The electrode is not specific to silver ions but can nevertheless be used in presence of Hg2+, Zn2+ and Cd2+. Anions show no interference. Silver can be estimated even in the presence of interfering ions by potentiometric titration using the membrane as an end point indicator electrode.

Studies with chromium ferricyanide epoxy resin-based membranes

Collidinium 12-molybdoarsenate, prepared by the reaction of sodium 12-molybdoarsenate and collidinium nitrate, is stable in water, acids and salt solutions Distribution coefficients have been determined for various metal ions in aqueous media at pH 3–4 The compound is highly selective towards thallium(I) and can be used for its separation from other cations Binary separations of microgram amounts of thallium(I) from large amounts of other metal ions have been carried out In ammonium nitrate media a large separation factor is obtained for the separation of thallium(I) from a caesium and rubidium ions, which has not so far been reported with other ion exchangers

Anubhav Jain

Papers

A transferable machine-learning framework linking interstice distribution and plastic heterogeneity in metallic glasses

Light‐Harvesting Materials: New Light‐Harvesting Materials Using Accurate and Efficient Bandgap Calculations (Adv. Energy Mater. 2/2015)

Working longer:hours of work and health

Studies with chromium ferricyanide epoxy resin-based membranes

Application of a collidinium molybdoarsenate ion-exchange column to the separation of thallium(I)