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Studies on Silk Fibroin Membranes(I) -Structure of Silk Fibroin Membranes and Their properties- (Silk Fibroin 막에 관한 연구(I) -Silk Fibroin막의 구조특성-)

  • 최해욱;박수민;김경환
    • Textile Coloration and Finishing
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    • v.6 no.1
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    • pp.62-70
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    • 1994
  • Silk fibroin was dissolved in 9.3 M LiBr aqueous solution at 4$0^{\circ}C$ for 1 hour. The dissolved silk fibroin was regenerated by casting the dialyzed solution into the membrane. The freshly prepared silk fibroin membrane was soluble in water and was. mainly consisted of random coil conformation. By the treatments in saturated water vapor at 3$0^{\circ}C$ and in 75% ethanolic aqueous solution (V/V), the insoluble membranes were obtained and the structure and morphology of those were investigated for the structure by means of X-ray diffraction analysis, infrared spectroscopy, thermal analysis. Rheovibron and scanning electron micrograph. Silk II type crystals were obtained by treating amorphous silk fibroin membrane in the random coil conformtion with 75% ethanol solution(V/V). Crystallization to silk II type crystals occured even after a few minutes, and a large number of silk II type crystals were formed after 30 mins. On the other and, the membrane treated in saturated water vapor was composed of the mixtures of silk I and silk II type crystals. A large number of silk I and silk II type crystals were formed after 24 hours. The micro brownian motion in the amorphous regions of silk fibroin membrane started at about 175~185$^{\circ}C$. $\alpha$ dispersion appeared at about 20$0^{\circ}C$ in the amorphous membrane, and at about 22$0^{\circ}C$ in the crystalline membrane. The crystallization of random coil conformation to silkII type crystals occured at about 215$^{\circ}C$. The surface, bottom and cross-section of the membranes were observed by scanning electrom microscope. Fine forms alike spherulites appeared at the surface of crystalline membrane.

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Separation and Recovery of Iodide in Radioactive Waste for $^129I$ (방사성폐기물 중의 $^129I$ 정량을 위한 요오드의 분리 및 회수)

  • 최계천;한선호;지광용;임석남;박상규
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.632-635
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    • 2003
  • For the disposal of low-level radwaste from nuclear power plant need the determination of levels of radio nuclides in radwaste. These nuclides include the difficult-to-measure nuclides, so indirect methodology for the determination of the difficult-to-measure nuclides have to be developed. In this work, for the determination of $^129I(t_{1/2}=1.57{\times}10^7 years)$ in low-level radwaste from nuclear power plant is investigated. Recovery of Iodide in simulated waste($UO_2$ pellet) as a soluble and radwaste(resin, woolen fabric)as a insoluble samples are measured. After pretreatment of sample, $I_2$ are extracted from aqueous solution with $CCl_4$. Then I are extracted from $CCl_4$ with 0.1M $NaHSO_3$ aqueous solution. iodide in aqueous solution are determined by ion chromatography. The overall recovery yield is 76.7 (RSD 1.7%) for mixed-acid digestion method. Incase of woolen fabrics, overall recovery yield is 74.3 (RSD 2.2%) and recovery of iodide in resin 56.5(RSD 5.6%) for alkaline fusion method.

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Effects of Extracting and Drying Method on Physical Properties of Alginates from Sea Tangle, Laminaria japonica (추출 및 건조방법이 다시마 (Laminaria japonica) 알긴산의 물성에 미치는 영향)

  • YOU Byeong Jin;LIM Yeong Seon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.4
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    • pp.340-345
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    • 2003
  • In order to choose the manufacturing method for extracting alginates from sea tangle, Laminaria japonica, three methods were applied. In Method I, alginates were extracted with NaOH solution from sea tangle powder and extracted alginates were precipitated and converted to alginic acid by $CaCl_2$ and HCI solution. Then alginic acid was converted to sodium alginates with $Na_2CO_3$ solution. Sodium alginates were precipitated with methyl alcohol and were resolved with hot water and this step was repeated three times. Method II was same to Method I except final step including that sodium alginates were precipitated and washed with methyl alcohol three times. Method III included that sodium alginates were extracted with $Na_2CO_3$ solution from sea tangle powder then sodium alginates were precipitated and washed with methyl alcohol three time. Extracting time increased with Increasing extracted alginates amounts but increasing rates were below $0.4\%/h.$ Alginates amounts recovered by Method III showed above 2 times more to those by Method I and II. Extracting time increased with increasing ash amount of sodium alginates but increasing rates were below $0.1\%/h.$ and that of sodium alginates extracted by Method III showed higher value $(5\%)$ than those by Method I and II. In the sodium alginates prepared by Method III, the amount of ash in alginates dried by air was $34.4\%,$ that by vacuum freeze drying was $47.8\%.$ Extracting time increased with decreasing average molecular weight (MW) and degree of polymerization (DP) of sodium alginates, MW and DP of alginates prepared by Method III were higher than those by Method I and II In same extracting time. Extracting time increased with decreasing rate of apparent viscosity change (SAV) of alginates solution, and SAV of alginates prepared by Method III showed higher value than those by Method I and II in same extracting time. SAV of alginates dried by air was higher than that by vacuum freeze drying. Relating equation among SAV MW and DP were MW = 60.066 (SAV) -93.950, DP =309.760 (SAV) -485.084 and MW = 0.914 (DP)+0.213.

The Indefinite Description Analysis of Belief Ascription Sentences: A Trouble with the Analysis\ulcorner

  • Sunwoo, Hwan
    • Lingua Humanitatis
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    • v.2 no.2
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    • pp.301-319
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    • 2002
  • In a recent paper, I have proposed an analysis concerning propositions and 'that'-clauses as a solution to Kripke's puzzle and other similar puzzles, which I now call 'the Indefinite Description Analysis of Belief Ascription Sentences.' I have listed some of the major advantages of this analysis besides its merit as a solution to the puzzles: it is amenable to the direct-reference theory of proper names; it does not nevertheless need to introduce Russellian (singular) propositions or any other new entities. David Lewis has constructed an interesting argument to refute this analysis. His argument seems to show that my analysis has an unwelcome consequence: if someone believes any proposition, then he or she should, ipso facto, believe any necessary (mathematical or logical) proposition (such as the proposition that 1 succeeds 0). In this paper, I argue that Lewis's argument does not pose a real threat to my analysis. All his argument shows is that we should not accept the assumption called 'the equivalence thesis': if two sentences are equivalent, then they express the same proposition. I argue that this thesis is already in trouble for independent reasons. Especially, I argue that if we accept the equivalence thesis then, even without my analysis, we can derive a sentence like 'Fred believes that 1 succeeds 0 and snow is white' from a sentence like 'Fred believes that snow is white.' The consequence mentioned above is not worse than this consequence.

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Studies on Licorice in Drug Preparations(I) Determination of Glycyrrhizin and Glycyrrhetinic acid by HPLC. (생약중의 감초에 관한 연구(I) HPLC에 의한 Glycyrrhizin 및 Glycyrrhetinic acid의 정량)

  • 백남호;박만기;박정일;김중선;서정진
    • YAKHAK HOEJI
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    • v.25 no.1
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    • pp.1-7
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    • 1981
  • Glycyrrhizin (GA) content in licorice was determined by a couple of methods using HPLC, respectively. In Method(I), GA content itself was determined from the licorice aqueous extract, while in Method (II) glycyrrhetinic acid (GHeA ; the aglicone of GA) content corresponding to the quantity of GA was measured from the chloroform extract of the hydrolyzed product of licorice aqueous extract. A reverse phase column Hibar Lichrosorb RP-18 (E. Merck) was used as the stationary phase. As the mobile phase MeOH: $H_{2}O$(0.05M-$NaH_{2}PO_{4}$)=58 : 42 solution in Method (I), and MeOH: $H_{2}O $: AcOH=78; 19: 3 solution in Method (II) were suitable, respectively. The value obtained by Method (II) appeared slightly higher than that by Method (I). The effect of some other herbal drugs on the assay of GA quantity in mixed sample was also observed in both above two methods. By Method (I) Cassiae Cortex, Rehmaniae Rhizoma, Paeoniae Radix, and Angelicae Radix gave the subtractive effect on the amount of GA compared with the value from licorice alone. In the case of Method (II) Cassiae Cortex and Rehmaniae Rhizoma appeared to have subtractive effect but Paeoniae Radix and Angelicae Radix scarcely showed any influence. Pachymae Fungus did not affect the GA content at all. It seems that glycyrrhizin in licorice interacts with certain components of other herbal drugs.

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Effects of Indole Oligomers Induced from Indole-3-carbinol on the Growth of MCF-7 Breast Cancer Cells

  • Kang, Kap-Suk;Leonard F. Bjeldanes
    • Preventive Nutrition and Food Science
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    • v.3 no.2
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    • pp.163-168
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    • 1998
  • Inhibitory effect of indole oligomers induced from indole-3-carbinol(I3C) on the growth of breast cancer cells was studied. We gernerated the reaction mixtures (RXM) at ambient temperature by treating a stirred aqueous solution of I3C (typeically 0.25ml) at a concentration of 12 $\mu$mol/ml) with hydrochloric acid (typically 28$\mu$l of a 1 mmol/ml solution). RXM was fractionated by the column chromatography. The fractions with similar UV-pattern were further fractionated by HPLC and 3.3'-diindoylmethane (DIM) and other indole oligomers were identified. I3C, RXM, and it derived indole compounds were added to MCF-7 cells and cultured in the presence of 10-7M estradiol for 7 days. the growth-inhibitory effect of I3C and DIM on the growth of MCF-7 cell was very strong. The synthetic DIM also revealed antiproliferative effect on MCF-7 cel. The fractions containing high DIM content (77%), were most effective in inhibiting MCF-7 cell growth induced by estradiol. With these results, we suggest that I3C and DIM might have anticarcinogenic effect on the breast cancer.

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Effect of Composition on the pH and Solution Potential of Mixed Solutions of Copper and Iron Chloride (염화(鹽貨)구리와 염화철(鹽貨鐵) 혼합용액(混合溶液)의 조성(組成)이 pH와 용액전위(溶液電位)에 미치는 영향(影響))

  • Lee, Man-Seung;Son, Seong-Ho
    • Resources Recycling
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    • v.17 no.6
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    • pp.17-23
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    • 2008
  • In order to simulate the leaching solution of copper sulfide ore in $FeCl_3$ solutions, synthetic solutions with composition of $FeCl_3$-$FeCl_2$-$CuCl_2$-CuCl-NaCl-HCl-$H_2O$ were prepared. The concentration of iron and copper chloride was varied from 0.1 to 1 m in synthetic solutions. The effect of composition on the mixed solution pH and potential at $25^{\circ}C$ was measured. When HCl concentration was constant, the increase of CuCl concentration increased solution pH. The increase of other solutes excluding HCl and CuCl decreased solution pH owing to the increase of the activity coefficient of hydrogen ion. A high CuCl concentration favored the redox equilibrium in the direction of Cu(I), while $FeCl_3$ had the opposite effect.

Application of Surfactant added DHF to Post Oxide CMP Cleaning Process (계면활성제가 첨가된 DHF의 Post-Oxide CMP 세정 공정에의 적용 연구)

  • Ryu, Chung;Kim, You-Hyuk
    • Journal of the Korean Chemical Society
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    • v.47 no.6
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    • pp.608-613
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    • 2003
  • In order to remove particles on surface of post-oxide CMP wafer, new cleaning solution was prepared by mixing with DHF (Diluted HF), nonionic surfactant PAAE (Polyoxyethylene Alkyl Aryl Ether), DMSO (Dimethylsulfoxide) and D.I.W.. Silicone wafers were intentionally contaminated by silica, alumina and PSL (polystylene latex) which had different zeta potentials in cleaning solution. This cleaning solution under megasonic irradiation could remove particles and metals simultaneously at room temperature in contrast to traditional AMP (mixture of $NH_4OH,\;H_2O_2$ and D.I.W) without any side effects such as increasing of microroughness, metal line corrosion and deposition of organic contaminants. This suggests that this cleaning solution would be useful future application with copper CMP in brush cleaning process as well as traditional post CMP cleaning process.

Effect of Oxygenation of Cardioplegic Solution on Electrical Stability and Postischemic Recovery of Cardiac Function after Ischemic Arrest in Isolated Rat Heart[ I ] (백서의 적출된 심장에서 심정지액의 산소화가 허혈성 심정지후 심기능 회복에 미치는 영향[I])

  • 윤재도
    • Journal of Chest Surgery
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    • v.25 no.2
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    • pp.125-130
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    • 1992
  • To evaluate the effect of oxygenation[95% O2+5% CO2] of St. Thomas Hospital No.2 cardioplegic solution[Plegisol], 20 isolated perfused rat hearts were studied under hyp-othermic[20oC] ischemic arrest for 2 hours with infusion of cardioplegic solution every 30 minutes throughout the ischemic period. Ten isolated hearts were studied with the oxygenated cardioplegic solution and 10 another isolated hearts with the nonoxygenated one. Mean oxygen tensions of the nonoxygenated and oxygenated cardioplegic solutions were 150mmHg and 470mmHg, respectively. Two in 10 hearts infused with the nonaxygenated cardioplegic solution were not recovered from nonworking heart due to persistent ventricular fibrillation. In comparing hem-odynamic parameters between both groups, the mean postischemic recovery[expressed as a percentage of its preischemic control value] was significantly greater with the oxygenated solution[in 10 recovered hearts] than the nonoxygenated solution[in 8 recovered hearts] [95.9$\pm$1.8% compared with 88.5$\pm$2.9% in peak aortic pressure, p<0.05, 75.7$\pm$5.2% compared with 43.5$\pm$6.5% in aortic flow, p<0.01, 75.5$\pm$4.6% compared with 54.1$\pm$5.6% in cardiac output, p<0.01, 78.3$\pm$4.6% compared with 60.3$\pm$4.6% compared with 60.3$\pm$6.2% in stroke volume, p<0.05, and 80.4$\pm$5.3% compared with 58.6$\pm$7.0% in dP/dT, p<0.05]. It is concluded that oxygenation of St. Thomas Hospital No.2 cardioplegic solution improves cardiac electrical stability and postischemic hemodynamic recovery after ischemic arrest in the isolated perfused rat heart.

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The Complexes of Iodobenzene with Halogens and Interhalogens in Carbon Tetrachloride (요오드벤젠과 할로겐 또는 할로겐間化合物 사이의 錯物에 관한 연구)

  • Choi, Sang-Up;Kim, Eung-Ryul
    • Journal of the Korean Chemical Society
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    • v.11 no.3
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    • pp.94-99
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    • 1967
  • The interactions of iodobenzene with iodine, iodine monobromide, iodine monochloride and chlorine in carbon tetrachloride solution have been investigated by means of ultraviolet spectrophotometric measurements. The results reveal the formation of one to one molecular complexes, $C_6H_5I{\cdot}I_2$, $C_6H_5I{\cdot}IBr$, $C_6H_5I{\cdot}ICl$, and $C_6H_5I{\cdot}Cl_2$, in solution. The equilibrium constants obtained at room temperature (about $21^{\circ}C$) for the formation of these four complexes are 0.23, 0.73, 1.2 and 0.070 l $mole^{-1}$, respectively. Comparison of these results with those reported in the literature on other complexes of similar type indicates that the relative stabilities of these complexes decrease in the following orders: ICl>IBr>$I_2$>$Br_2$>$Cl_2$ $C_6H_5I$>$C_6H_6$>$C_6H_5Br$>$C_6H_5Cl$>$C_6H_5F$.

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