• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.958-968
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• 1998

Porous silica ceramics were prepared using DCCA(Drying Control Chemical Additives) Such as uncharged polymer(Polyethylene glycol) and protein (Lipase) under H2O/Low-grade TEOS=10 C2H5OH/Low-grade TEOS=1 HC1/Low=grade TEOS=0.01 After Plain which doesn't added DCCA and samples of 11 sorts which varied molecular weight of PEG(Mw=600, 1000, 2000) quantity of Lipase and concentration of wat-er were synthesized gellation time and thermal analysis were investigated. After heat-treated at 600, cry-stal structures analyses of SiO2 polymer and characteristics of pores were investigated. Gellation time was retarded about 2-6 times as compared with plain resulting in addition of DCCA and crystal structures ex-hibited amorphous state. Moreover as increase of water a short gellation time was obtained. The samples added PEG showed increase of specific surface areas up to 20-40% and had micropores while those of Lipase were decreased about 90% and showed broad pore size distribution.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.950-955
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• 1998

The objective of this study was to investigate the effect of running time, operating pressure, feed concentration and circulation rate on the permeation flux and the rejection rate in cross-flow ultrafiltration of polyethylene glycol(PEG) solution of molecular weight($M_w$) 8000 and 20000. The membranes used for this study were MWCO(Molecular Weight Cut-off) of 6 K and 20 K. The experiments were performed at the operating pressures of 7, 14 and 28 psi, the circulation rates of 1000 mL/min and 2000 mL/min, and the feed concentration of 100 mg/L and 1000 mg/L. At a constant pressure, the permeation flux and the observed rejection($R_o$) appeared to be approximately constant within the range of running time, 0~480 min. The permeation flux increased with increasing the operating pressure, and it increased with decreasing the feed concentration and decreasing Mw of PEG at a given pressure. On the other hand, $R_o$ decreased slightly with increasing the operating pressure. However, $R_o$ increased with increasing the feed concentration and increasing of $M_w$ of PEG at a given pressure. The variation in circulation rates did not cause any significant influence on the permeation flux. Increasing of circulation rate caused the increase of $R_o$, and $\alpha$ was increased substantially with the decrease of $M_w$ of PEG. The dimensionless parameter. permeability ratio($\alpha$), which was used to investigate flux-pressure behavior, was increased with the increase in circulation rate and operating presure. The value of $\alpha$ was less than 1 in all cases. The estimated intrinsic rejection(R). which was obtained from mass transfer coefficient, was decreased with the increase of operating pressure. However R increased with the increase of linear velocity of feed and $M_w$ of PEG.

• The Korean Journal of Mycology
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• v.24 no.2 s.77
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• pp.111-126
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• 1996

Transfer of the isolated nuclei from Lentinus edodes into protoplasts of Pleurotus florida was induced with polyethlene glycol (PEG) and $CaCl_2$. The intergeneric transfer products were classified into nuclear hybrid, heterokaryon or synkaryon, and reconstituted cell. These progenies except nuclear hybrids formed mature fruiting bodies on sawdust rice bran medium. Formation of fruit bodies was influenced by several factors such as light, temperature, nutrition and physic state of the culture media. Most of fruiting body characters were similar to those of P. florida in synkaryon and L. edodes in reconstituted cell, respectively. All these basidiocarps had clamp connections though initial heterokaryon colonies were lacking. Isozyme patterns of intergeneric progenies were quite different from those of parents. DNA polymorphisms of transfer products were also compared by random amplified polymorphic DNAs (RAPD) analysis based on polymerase chain reaction. The RAPD patterns were different from those of donor and recipient. DNA fingerprints ranged in size from 0.25 to 4.0 Kb. On the basis of RAPD, the transfer products were classified into five groups. Two synkaryon were analysed with distribution of progenies and segregation of genetic markers by random spore analyses. The genetic markers were segregated into wild type and riboflavine requiring auxotrophs.