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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Energy harvested directly from sunlight offers a desirable approach toward fulfilling, with minimal environmental impact, the need for clean energy. Solar energy is a decentralized and inexhaustible natural resource, with the magnitude of the available solar power striking the earth’s surface at any one instant equal to 130 million 500 MW power plants.1 However, several important goals need to be met to fully utilize solar energy for the global energy demand. First, the means for solar energy conversion, storage, and distribution should be environmentally benign, i.e. protecting ecosystems instead of steadily weakening them. The next important goal is to provide a stable, constant energy flux. Due to the daily and seasonal variability in renewable energy sources such as sunlight, energy harvested from the sun needs to be efficiently converted into chemical fuel that can be stored, transported, and used upon demand. The biggest challenge is whether or not these goals can be met in a costeffective way on the terawatt scale.2

http://pubs.acs.org/doi/pdf/10.1021/cr1002326

Solar Water Splitting Cells

/pdf/self-assembled-monolayers-of-thiolates-on-metals-as-a-form-1neb0hj3k4.pdf

Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Doxorubicin Uptake and Release from Microgel Thin Films

A reflectance method has been used to assess conduction band edge energies (Ecb) for nanocrystalline TiO2(anatase) electrodes in contact with aqueous electrolytes. The measurements, which were made over a range of nearly 40 pH units, reveal a Nernstian dependence of Ecb upon pH over most of this range, i.e., a −64 mV shift per unit decrease in log(proton activity) between H0 = −8 and H- = +23. Electrochemical quartz crystal microbalance (EQCM) measurements have established that charge compensating proton uptake occurs at potentials negative of Ecb. Uptake occurs over the entire EQCM-accessible pH range (H0 = −5 to pH = +11). The combined findings are inconsistent with Ecb control solely via surface protonation and deprotonation reactions, whose pKa's occur in the vicinity of pH 4 and 10. They are consistent, however, with a mechanism whereby:  (a) electrochemical generation of Ti(III) trap sites, in the log(proton activity) range from H0 = −8 to H- = +23, is accompanied quantitatively by proton intercalat...

/pdf/energetics-of-the-nanocrystalline-titanium-dioxide-aqueous-5cq0vygik1.pdf

Energetics of the Nanocrystalline Titanium Dioxide/Aqueous Solution Interface: Approximate Conduction Band Edge Variations between H0 = −10 and H- = +26

L. Andrew Lyon

Papers

Doxorubicin Uptake and Release from Microgel Thin Films

Energetics of the Nanocrystalline Titanium Dioxide/Aqueous Solution Interface: Approximate Conduction Band Edge Variations between H0 = −10 and H- = +26

Thermally modulated insulin release from microgel thin films.

Synthesis and characterization of pH-responsive copolymer microgels with tunable volume phase transition temperatures

Peptide-Functionalized Nanogels for Targeted siRNA Delivery