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’

We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. PCMs have been widely used in latent heat thermal-storage systems for heat pumps, solar engineering, and spacecraft thermal control applications. The uses of PCMs for heating and cooling applications for buildings have been investigated within the past decade. There are large numbers of PCMs that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also summarizes the investigation and analysis of the available thermal energy storage systems incorporating PCMs for use in different applications.

Review on thermal energy storage with phase change materials and applications

http://libir.tmu.edu.tw/bitstream/987654321/43034/1/4.pdf

Review of second-order models for adsorption systems.

Objective To evaluate the effect of additives on absorption of Coptis chinensis total alkaloid and their pharmacokinetics in mice. Method The mice were fed with the mixture of C. chinensis total alkaloids and additives (1:1). And then the feces and orbital blood were taken to detect the content of total alkaloids by HPLC and their pharmacokinetics. Result Glutin could make the absorption of jatrorrhizine, coptisine, berberine and total alkaloids increased by 30%. Tween 80 and arabic gum did not affect the absorption of berberine, but inhibit that of other alkaloids. There had no influence of lecithin on the absorption of alkaloids. The peak time of total alkaloids in blood were 2 h (Cmax 1=5.9 mg x L(-1)) and 5.0 h (Cmax 2=3.4 mg x L(-1)), respectively, AUC was 17.6 mg x h x L(-1), the elimination of Half-life t1/2 was 5.2 h. After addition of glutin, the peak time of total alkaloids in blood were 1.5 h (Cmax 1=7.6 mg x L(-1)) and 4.8 h (Cmax 2=8.5 mg x L(-1)), AUC was up to 31.1 mg x h(-1) x L(-1), the elimination of Half-life t1/2 was 6.2 h. Conclusion Glutin could accelerate the mice on the absorption of C. chinensis total alkaloids, to extend the elimination half-life, increase the blood concentration and bioavailability.

Effect of additives on absorption of Coptis chinensis total alkaloids and pharmacokinetics in mice

Abstract The effects of solid fermentation conditions such as the incubation period, fermentation temperature, initial pH, and inoculum concentration on protease production and in vitro digestibility of flaxseed protein with Aspergillus oryzae 3.951 were reported. From 72h of fermentation at 30 °C, protease activity and protein digestibility were significantly increased. Maximum protease activity was obtained for high temperature-pressed flaxseed meal (HFM) and cold-pressed flaxseed meal (CFM) with initial pH 4.4-5.2, inoculum concentration 0.5×106 spores /mL. The results showed that the melting temperature (Td) increased by 4.8 °C and 7.6 °C for fermented CFM and HFM, respectively. In DSC tests, the enthalpy value is defined as the quantity of heat absorbed by samples during warming process. Results indicate that the enthalpy value of fermented samples significantly reduced from 186.5 J/g to 148.9 J/g (CFM) and from 187.0 J/g to 163.3 J/g (HFM). The result suggests that the lower molecular weight protein was degraded by protease, and the remaining were globulin with greater thermal stability and higher molecular weight.

The digestibility and thermal properties of fermented flaxseed protein

An efficient auto-continuous globing process was developed with a self-built apparatus to synthesize pure silica aerogel microspheres (PSAMs) using sodium silicate as a precursor and water as a solvent. A hydrophobic silica aerogel microsphere (HSAM) was obtained by methyl grafting. A reinforced silica aerogel microsphere (RSAM) was prepared by polymer cross-linking on the framework of the silica gel. The pH value of the reaction system and the temperature of the coagulating bath were critical to form perfect SAMs with a diameter of 3.0 ± 0.2 mm. The grafted methyl groups are thermally stable up to 400 °C. Polymer cross-linking increased the strength significantly, owing to the polymer coating on the framework of silica aerogel. The pore volumes of HSAM (6.44 cm3/g) and RSAM (3.17 cm3/g) were much higher than their state-of-the-art counterparts. Their specific surface areas were also at a high level. The HSAM and RSAM showed high organic sorption capacities, i.e., 17.9 g/g of pump oil, 11.8 g/g of hexane, and 22.2 mg/g of 10 mg/L methyl orange. The novel preparation method was facile, cost-effective, safe, and eco-friendly, and the resulting SAM sorbents were exceptional in capacity, dynamics, regenerability, and stability.

/pdf/auto-continuous-synthesis-of-robust-and-hydrophobic-silica-17lrb280.pdf

Auto-Continuous Synthesis of Robust and Hydrophobic Silica Aerogel Microspheres from Low-Cost Aqueous Sodium Silicate for Fast Dynamic Organics Removal

Theory of UWB Antenna Elements

Understanding the process of fouling is of utmost importance considering its usually considerable impact on the overall performance of a process plant. Crystallisation fouling is one of the most commonly encountered problems in industry. Despite significant advances made by crystallographers in understanding mechanisms of crystallisation, researchers working in the filed of fouling in heat exchangers have tended to ignore certain basic features of crystallization. Generally the rate of crystallization fouling is simply taken as a function of concentration difference occurring in heat exchangers and reaction rate constant. The aim of this study was to analyse crystalline deposits forming on the heat transfer surface and hence determine the effect of particles on crystallization fouling. It was found that deposit formation pattern changed significantly when particles of the crystallizing material were introduced into the process solution. These particles settled on the heat transfer surface and provided new nucleation sites for crystal growth. As a result, many additional crystals were formed and the rate of crystallization enhanced significantly. In contrast, particulate fouling by these particles was found to be insignificant. Based on these results, it is argued that there is a need to modify the crystallization fouling models to incorporate the enhancement effects of the particles.

Xiao Dong Chen

Papers

Effect of additives on absorption of Coptis chinensis total alkaloids and pharmacokinetics in mice

The digestibility and thermal properties of fermented flaxseed protein

Auto-Continuous Synthesis of Robust and Hydrophobic Silica Aerogel Microspheres from Low-Cost Aqueous Sodium Silicate for Fast Dynamic Organics Removal

Theory of UWB Antenna Elements

Analysis of Deposits to Study the Effect of Particles on Crystallisation Fouling