• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.46-51
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• 2006

This paper reports on the effects of silicone oils, used as processing agents, on the recovery of hydrophobicity of silicone rubber. The recovery of hydrophobicity was evaluated by the measuring the contact angle, the surface electrical resistance and SEM. Here, we formed artificial contamination on the surface of samples, which scratched by sand papers and alumina powders. There was small recovery of hydrophobicity on the surface of SIR-A that silicone oil was not added. In both oil-added samples, SIR-B and SIR-C, recovery of hydrophobicity was achieved greatly. The surface of SIR-C showed that a lot of silicone oil was observed due to migration of oil, relatively in comparison with SIR-B. The tendency of recovery of hydrophobicity expressed by contact angle was in a good agreement with electrical property as determined by surface resistivity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.133-140
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• 2002

This paper aims to investigate the effect of silicone oils as processing agent affecting the loss and recovery of hydrophobicity. The recovery of hydrophobicity was evaluated by the measurement of the surface electrical resistivity and the contact angle on the SIR surface. Two kinds of silicone oils (1 and 2) having different molecular weight were selected under a consideration of hydrophobicity and processability. SIR specimens were exposed to corona discharges in air and the specimens were analyzed with contact angle and surface resistance measurements. It was observed that the contact angle and the surface resistivity of SIR increase gradually with testing time. The fast recovery of hydrophobicity of SIR, expressed by the increment of contact angle and surface resistivity, was showed in SIR2 containing silicone oil 2.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.28-32
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• 1993

In order to elucidate the temperature and pressure effect on the oil expression of perilla seed, recovery of expressed oil (REO) and volumetric strain of both roasted and unroasted perilla seeds were observed at different temperature, pressure and for different periods of press. In this experiment, moisture content of perilla seed was adjusted to 2.5% and temperature used were 30, 40, 50 and $60^{\circ}C$. Pressure applied were 10, 30, 50 and 70 MPa, and periods of press were 5, 7, 9 and 11 min. As temperature and pressure were increased or periods of press was lengthened, REO and volumetric strain of pressed cake were increased. Maximum REO of unroasted perilla seeds were found to be 85.59% and those of roasted perilla seeds be 85.30%, at 70 MPa, $60^{\circ}C$, and for 11 min. Viscosity of expressed oil were exponentially dependent on temperature and REO were increased as viscosity was decreased. From statistical analysis between effects of expression factors and REO and volumetric strain of pressed cake, importance of their effects was decreased in the order of pressure, temperature, $temperature{\times}pressure$ and periods of press. The multiple regression equation between REO(Y) and temperature (T), pressure (P), and periods of press (D) were as follows; $Y=7.95+36.85P+1.12T^2-0.55TP-5.08P^2\;r^2=0.97$ for unroasted perilla seed (p<0.01), $Y=4.50T+39.23P+0.83T^2-1.71P-5.07P^2\;r^2=0.99$ for roasted perilla seed (p<0.01).

• Applied Biological Chemistry
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• v.37 no.1
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• pp.14-18
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• 1994

In order to elucidate the interaction effect between temperature and moisture content on the oil expression of perilla seed, recovery of expressed oil (REO) and volumetric strain of pressed cake (VSPC) of both roasted and unroasted perilla seeds were observed at different temperatures of 30, 40, 50 and $60^{\circ}C$, and different moisture contents of 2.5, 4.5, 6.5 and 8.5% (w.b). And duration of press was 11 min and applied pressure was 50 MPa. At the low temperature REO and VSPC of roasted and unroasted perilla seed increased in high moisture content and at the high temperature those increased in low moisture content. But REO and VSPC at 8.5% moisture content were decreased without relation to temperature. From the analysis of variance between expression factors and REO and VSPC, temperature and moisture contents showed high significance. Also the interaction effect between temperature and moisture content was higher than temperature. In our experimental conditions, the highest interaction effect between expression factors was observed in the range of $2.5{\sim}4.5%$ of moisture content in all temperatures. The maximum REO of unroasted perilla seeds was observed as 84.4% at 2.5% of moisture content and $60^{\circ}C$, and that of roasted one was as 84.3% at 6.5% of moisture content and $30^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.785-789
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• 1995

In order to optimize the batch expression of sesame oil, recovery of expressed oil(REO) from roasted and unroasted sesame seeds were observed at different temperature, pressure, pressing duration and moisture content, and relatinship between REO and effects of expression factors were analysed. REO was high at 2.5~4.5% moisture content, 30~$50^{\circ}C$ and 30~50MPa, and decreased abruptly with increasing moisture content above 4.5%. The optimum temperature, pressure, pressing duration and moisture content were $40.1^{\circ}C$, 54.4MPa, 21.7min and 1.3% for unroasted seeds and $44.4^{\circ}C$, 37.8MPa, 14.4min and 2.52% for roasted seeds, respectively. REO in optimum condition was 84.6% in unroasted seed and 81.7% in roasted seed. From the statistic analysis between effects of expression factors and REO, importance of their effects was decreased in the order of moisture content, pressure, temperature and pressing duration. And also interaction effects were high in $pressure{\times}moisture$ content, $temperature{\times}moisture$ content and temperature pressure. The multiple regression equation between REO(Y) and temperature(T), pressure(P), moisture content(M), and pressing duration(D) were as follows ; $Y=18.20$ $35.66P$＋$24.52M-4.45P^{2}-1.20TM-4.02PM-6.62M^{2},\;r^{2}=0.89$, for unrosated sesame seed, $Y=117.93$＋$16.40P-58.61M-2.75P^{2}$＋$1.79TM-1.65PM$＋$7.16M^{2},\;r^{2}$$=0.91$ for roasted sesame seed.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.739-747
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• 2018

The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57.4%. Plasmids pTf16 harboring the tig gene and pG-Tf2 containing the tig and groEL-groES genes had no visible impact on PAI expression. The lytic protein E was then introduced into the recombinant Escherichia coli to develop a cell autolysis system. A 35% activity of total intracellular PAI was released from the cytoplasm by suspending the lysed cells in distilled water. The PAI recovery was further improved to 81% by optimizing the release conditions. The lipase from Rhizopus oryzae was also expressed in E. coli, with an extracellular activity of 110.9 U/ml. By using the free PAI and lipase as catalysts, a joint system was established for producing CLA from sunflower oil. Under the optimized conditions, the maximum titer of t-10,c-12-CLA reached 9.4 g/l. This work provides an effective and low-cost strategy to improve the solubility and recovery of the recombinant intracellular PAI for further large-scale production of CLA.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.12a
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• pp.19-32
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• 1992

Objectives of this study are : 1) to utilize capillary theory and obtain pore-size distribution profiles from moisture-suction relationships using Laplace theory. 2) to investigate the behavior of Light Non-Aqueous Phase Liquids(LNAPLs) in the subsurface environment and to develop several predictive relationships which can be used to assess the effectiveness of various LNAPLs remediation technologies. The relationship to predict pore-size distribution function expressed in differencial equation is found by using capillary theory. Also, experiments are conducted to : the various LNAPLs subjected to vadose zone drainage, groundwater table drainage, waterflooding with surfactants. The experiments are performed with #2 heating oil, jet fuel. and kerosene. Several relationships have been derived describing the effect of various properties and process parameters on the LNAPL residual saturation.