An Extended ISM for Globally Multimodal Function Optimization by Genetic Algorithms

When attempting to optimize a function where exists several big-valley structures, conventional GAs often fail to find the global optimum. Innately Split Model (ISM) is a framework of GAs, which is designed to avoid this phenomenon called UV-Phenomenon. However, ISM doesn't care about previously-searched areas by the past populations. Thus, it is possible that populations of ISM waste evaluation cost for redundant searches reaching previously-found optima. In this paper, we introduce Extended ISM (EISM) that uses search information of past populations as trap to suppress overlapping searches. To show performance of EISM, we apply it to some test functions, and analyze the behavior

EFFECT OF HIGH TEMPERATURE AND HIGH HUMIDITY TREATMENT ON BENDING PROPERTIES OF WOOD

Japanese cedar (Cryptomeria Japonica D. Don) 110 110 1000-mm green boxed-heart timbers were dried under high temperature (110-140C) and high humidity (0.01-0.24 MPa gauge pressure) conditions until the weight remained unchanged. Then strength properties were examined. Wood became brittle because of the high temperature and high humidity treatment. We hypothesize that the wood was seriously damaged by hydrolysis because of the long treatment time used in this study and that the large cross-sectional area and high set gauge pressure lengthened the time of water loss from the wood. We considered viscosity and plasticity, rather than elasticity, to be the main factors that contributed to the decrease of work for rupture

Effect of dispersed phase viscosity on maximum droplet generation frequency in microchannel emulsification using asymmetric straight-through channels

Effect of dispersed phase viscosity on maximum droplet generation frequency in microchannel emulsification using asymmetric straight-through channel

Rapid generation of highly uniform droplets using asymmetric microchannels fabricated on a single crystal silicon plate

A microfluidic device can be identified by the fact that it has one or more channels with at least one dimension less than 1 mm. The most common types of microfluidic devices are: (i) soft microfluidic devices fabricated in elastomeric materials such as PDMS by soft lithography [1], (ii) glass devices manufactured in quartz glass or glassy polymers such as PMMA by etching or micromachining [2], and (iii) microchannel (MC) array devices fabricated in silicon by photolithography and wet-etching or deep-reactive ion etching processing [3]. Microfluidic devices can be used for capillary electrophoresis [4], liquid-liquid extraction [5], immunoassays [6], cellomics [7], proteomics [8], DNA analysis [9], blood rheology measurements [10], microreactors [11], droplet formation [2], etc. The soft microfluidic devices such as T-junctions and flow focusing devices are suitable for rapid generation of monodispersed droplets with a coefficient of variation (CV) in a dripping regime of generally less than 3 %. Although the frequency of drop production can be as high as 7000 Hz, the overall productivity in terms of volume flow rate of the disperse phase is very low because the droplets are formed from a single channel. Silicon MC array devices are much more suitable for large-scale applications because the total number of microchannels on a chip can be hundreds of thousands. The aim of this work was to investigate the generation of uniform droplets at high production rates using novel asymmetric MC array microfabricated on a silicon plate [12]. Monodispersed emulsion droplets are much more favourable both in fundamental studies and practical applications. Emulsion appearance and rheology, stability against Oswald ripening and creaming, and the suitability of droplets as templates to the production of solid micro- and nano-particles are strongly influenced by their particle size distribution

Production of uniformly sized emulsion drops at high production rates using asymmetric micro channel plates

The purpose of this work was to investigate maximum disperse phase flux required for production of monodisperse drops in a straight-through microchannel (MC) array device. The experiments have been carried out using single-crystal silicon MC plate consisting of about 23,000 asymmetric MCs fabricated by photolithography and deep reactive ion etching (DRIE). Each MC consisted of a rectangular 50×10 μm slot and a circular 10 μm-diameter hole in the middle of each slot. A depth of the hole was 70 μm and the slot depth was 30 μm. The dispersed phase was soybean oil, MCT (middle-chain fatty acid triglyceride) oil and n-tetradecane with a viscosity at 293 K of 50, 20, and 2.7 mPa·s, respectively. The continuous phase was 2 wt% Tween 20 or SDS. (Continues...)

Generation of highly uniform droplets using asymmetric microchannels fabricated on a single crystal silicon plate: effect of emulsifier and oil types

Uniform droplets of soybean oil, MCT (medium-chain fatty acid triglyceride) oil and n-tetradecane with a mean diameter of 26–29 μm have been generated using asilicon 24 × 24 mm microchip consisting of 23,489 asymmetric microchannels fabricated by photolitography and deep-reactive ion etching. Each microchannel consisted of a circular 10-μm diameter straight hole with a length of 70 μm and a 50 × 10 μm rectangular microslot with a depth of 30 μm. At the constant oil flux of 10 L m− 2 h− 1, the percent of active channels increased with increasing the oil viscosity and ranged from 4% for n-tetradecane to 48% for soybean oil. The size distribution span for SDS (sodium dodecyl sulphate)- and Tween 20 (polyoxyethylene (20) sorbitan monolaurate)-stabilized soybean and MCT oildroplets was 0.21–022. The ability of asymmetricmicrochannels to generate monodisperse soybean oildroplets at the very low SDS concentration of 0.01 wt.% has been demonstrated. At the SDS concentration below the CMC, the generated droplets tend to attach to the plate surface, whereas at the higher SDS concentration they detach from the plate as soon as they are formed. The agreement between the experimental and CFD (Computational Fluid Dynamics) simulation results was excellent for soybean oil and the poorest for n-tetradecane