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

A review on the angle of repose of granular materials

Hydrodynamic and hydromagnetic stability

Advances in laser, microwave, and similar technologies have led to recent developments of thermal treatments for disease and injury involving skin tissue. In spite of the widespread use of heating therapies in dermatology, they do not draw upon the detailed understanding of the biothermomechanics of behavior, for none exists to date, even though each behavioral facet is well established and understood. It is proposed that a detailed understanding of the coupled biological-mechanical response under thermal agitation will contribute to the design, characterization, and optimization of strategies for delivering better treatment. For a comprehensive understanding on the underlying mechanisms of thermomechanical behavior of skin tissue, recent progress on bioheat transfer, thermal damage, thermomechanics, and thermal pain should be systematically reviewed. This article focuses on the transfer of heat through skin tissue. Experimental study, theoretical analysis, and numerical modeling of skin thermal behavior are reviewed, with theoretical analysis carried out and closed-form solutions obtained for simple one-layer Fourier theory based model. Non-Fourier bioheat transfer models for skin tissue are discussed, and various skin cooling technologies summarized. Finally, the predictive capacity of various heat transfer models is demonstrated with selected case studies. DOI: 10.1115/1.3124646

Mathematical Modeling of Skin Bioheat Transfer

Effects of thermal properties and geometrical dimensions on skin burn injuries.

Numerical simulation of heat transfer in packed pebble beds: CFD-DEM coupled with particle thermal radiation

The pebble bed high temperature gas-cooled reactor is a promising generation-IV reactor, which uses large fuel pebbles and helium gas as coolant. The pebble bed flow is a fundamental issue for both academic investigation and engineering application, e.g., reactor core design and safety analysis. This work performed a review of recent progress on pebble flow study, focusing on the important issues like pebble flow, gas phase hydrodynamics, and inter-phase heat transfer (thermal hydraulics). Our group’s researches on pebble flow have also been reviewed through the aspects of phenomenological observation and measurement, voidage distribution, geometric and parameter optimization, pebble flow mechanisms, flow regime categorization, and fundamentals of modelings of pebble flow and radiation. Finally, the major problems or possible directions of research are concluded which would be some of our focuses on the pebble bed flow study.

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Shengyao Jiang

Papers

Effects of thermal properties and geometrical dimensions on skin burn injuries.

Numerical simulation of heat transfer in packed pebble beds: CFD-DEM coupled with particle thermal radiation

A review of pebble flow study for pebble bed high temperature gas-cooled reactor

Effect of scale on the modeling of radiation heat transfer in packed pebble beds

DEM simulations and experiments of pebble flow with monosized spheres