October 14, 2008 was the world’s first Open Access Day!

SPARC (the Scholarly Publishing and Academic Resources Coalition), the Public Library of Science (PLoS), and Students for FreeCulture have jointly announced the first international Open Access Day. Building on the worldwide momentum toward Open Access (OA) to publicly funded research, Open Access Day will create a key opportunity for the higher education community and the general public to understand more clearly the opportunities of wider access and use of content. Open Access Day will help to broaden awareness and understanding of OA, including recent mandates and emerging policies, within the international higher education community and the general public.
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14th October, 2008 No Comments

In recent years, scientific publishing has changed profoundly as the Internet simplified access to the scientific journals that once required a trip to a university library. That ease of access has caused many to question why commercial publishers are able to dictate the terms by which publicly funded research is made available to the public that paid for it. Open access proponents won a big victory when Congress voted to compel the National Institutes of Health to set a policy of hosting copies of the text of all publications produced by research it funds, a policy that has taken effect this year. Now, it appears that the publishing industry may be trying to get Congress to introduce legislation that will reverse its earlier decision under the guise of strengthening copyright protections.
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17th September, 2008 No Comments

Our work on AIMD simulation of CL-20 thermal decomposition just get published in the J. Phys. Chem. B!

CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane or HNIW) is a high-energy nitramine explosive. To improve atomistic understanding of the thermal decomposition of CL-20 gas and solid phases, we performed a series of ab initio molecular dynamics simulations. We found that during unimolecular decomposition, unlike other nitramines (e.g., RDX, HMX), CL-20 has only one distinct initial reaction channel—homolysis of the N—NO₂ bond. We did not observe any HONO elimination reaction during unimolecular decomposition, whereas the ring-breaking reaction was followed by NO₂ fission. Therefore, in spite of limited sampling, that provides a mostly qualitative picture, we proposed here a scheme of unimolecular decomposition of CL-20. The averaged product population over all trajectories was estimated at four HCN, two to four NO₂, two to four NO, one CO, and one OH molecule per one CL-20 molecule. Our simulations provide a detailed description of the chemical processes in the initial stages of thermal decomposition of condensed CL-20, allowing elucidation of key features of such processes as composition of primary reaction products, reaction timing, and Arrhenius behavior of the system. The primary reactions leading to NO₂, NO, N₂O, and N₂ occur at very early stages. We also estimated potential activation barriers for the formation of NO₂, which essentially determines overall decomposition kinetics and effective rate constants for NO₂ and N₂. The calculated solid-phase decomposition pathways correlate with available condensed-phase experimental data.

Isayev, O., Gorb, L., Qasim, M., Leszczynski, J. (2008). Ab Initio Molecular Dynamics Study on the Initial Chemical Events in Nitramines: Thermal Decomposition of CL-20. Journal of Physical Chemistry B, 112(35), 11005-11013. DOI: 10.1021/jp804765m

28th August, 2008 No Comments

Science FAQ:

Q: What do you get when you cross an elephant and a grape?
A: Elephant x Grape x sin(alpha)
Q: What do you get when you cross an Elephant and a mountain climber?
A: You can’t cross a vector and a scaler!

Q: What is the difference between a Quantum Theorist and a Beauty Therapist?
A: The Quantum Theorist uses Planck’s Constant as a foundation, whereas the Beauty Therapist uses Max Factor.

Q: Why does e^x hate going to parties?
A: Because no matter how hard he tries, he always fails to integrate.

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8th July, 2008 No Comments

With the June 9 announcement that the IBM supercomputer “RoadRunner” is the first system to reach the 1 petaflop/s level, the HPC community is entering a realm of unprecedented computing power.

Roadrunner supercomputer, built by IBM with funding from the National Nuclear Security Administration (NNSA) for Los Alamos National Laboratory, achieved a long-sought supercomputing goal: performing more than a thousand trillion operations per second, or petaflop/s. Roadrunner is the first supercomputer to use a hybrid processor architecture, which is based on 6,912 dual-core Opteron X64 processors from Advanced Micro Devices (AMD) and 12,960 IBM Cell Broadband Engine™ (Cell BE) processing elements. The Roadrunner system has 98 terabytes of memory, and is housed in 278 refrigerator-sized, IBM BladeCenter® racks occupying 5,200 square feet. Its 10,000 connections – both Infiniband and Gigabit Ethernet — require 55 miles of fiber optic cable. Roadrunner weighs 500,000 lbs. At the end of May, the system posted a peak performance of 1.026 petaflop/s running the Linpack benchmark. This test consisted of solving linear equations involving more than 2 million equations and an equal number of unknowns. Roadrunner is also rated as very energy (performance/watt) efficient (green).

For me, breaking the petaflop/s barrier is the equivalent of a runner finally running the 100-meter race in 9.5 seconds — a level of performance everyone hopes for but proves elusive to actually achieve. This will be the third time at ISC that we will have a presentation about the almost magical surpassing of a thousand-fold increase in HPC performance. Twenty-two years ago, in 1986, the legendary Cray 2 passed the 1 gigaflop/s level, and in June of that year we held the first ISC. Eleven years later, when the Intel ASCI Red system landed atop the 9^th TOP500 list presented at the conference, this was the first time a system reached the teraflop/s level. And now RoadRunner has cracked the next magical barrier and will be number one on the 31^st edition of the TOP500 list.

said Prof. Hans Meuer, general chair of ISC and founder of the TOP500 list.

11th June, 2008 No Comments