• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.463-469
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• 2015

Purpose: A hydrogel including alginate and $CaCl_2$ extracted from seaweed was manufactured, and their physical properties were investigated. Also, its applicability as contact lenses was examined. Methods: A film-type sample used in this experiment was manufactured using 2-hydroxyethyl methacrylate (HEMA), which is the raw material of hydrogel contact lenses; azobisiobutyonitile (AIBN), which is an initiator and ethylenglycoldimethacrylate (EGDMA), which is a cross-linking agent. It was hydrated in a PBS solution for 24 hours, and an interpenetrating polymer network (IPN) was formed in 1% and 2% alginate and 1%, 3%, and 5% $CaCl_2$ solutions for 24 hours, respectively. Results: The measurement of the physical properties of the film after the IPN showed that the moisture content was 30.89~36.89%, the refractive index was 1.431~1.441, the contact angle was $62.98{\sim}80.45^{\circ}$, and the tensile strength was 2.378~4.215 ($gf/mm^2$). Also, the physical properties hardly changed as the content of alginate increased, and the moisture content decreased as the content of $CaCl_2$ increased. As a result of the IPN, the moisture content and contact angle decreased compared to those of basic HEMA, but the tensile strength increased. The tensile strength of the second IPN was higher than that of the first IPN. In the case of $CaCl_2$, for the sample polymerized for 24 hours and the second IPN sample with 2% alginate, the contact angle decreased as the content of $CaCl_2$ increased. Conclusions: In this study, the tensile strength increased as the content of $CaCl_2$ increased, and the wettability increased as a result of IPN of alginate and $CaCl_2$. The hydrogel containing the alginate and $CaCl_2$ was confirmed possible utilization as contact lens material.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.207-216
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• 2009

Three distinct types of fluid inclusions in amethyst and quartz crystals are associated with metamorphic events in the Korea Amethyst deposit from Uljin-Gun, Gyeongbuk Province. The amethyst displays bimodal grain size distribution in fine-grained, strain-free equigranular quartz with coarse-grained quartz grains with kink bands and undulose extinction. Type I inclusions are liquid-rich and salinity is 0~7 wt% NaCl and the homogenization temperatures ($T_h$) $91{\sim}231^{\circ}C$ with eutectic temperatures ($T_e$) $-52{\sim}-20^{\circ}C$. Type II inclusions are vapor-rich (80~90 vol%). The salinity and $T_h$ ranges 3~6 wt% NaCl and $230{\sim}278^{\circ}C$, respectively with $T_e$ $-56{\sim}-23^{\circ}C$. Type III inclusions contain a daughter mineral other than NaCl. The salinity ranges 32~36 wt% NaCl and $T_h$ $210{\sim}271^{\circ}C$. The textural and fluid inclusion evidences suggest that the host Buncheon granite gneiss and Amethyst pegmatite experienced dynamic recrystallization and the studied fluid inclusions are metamorphic in origin. The metamorphic event possibly occurred at higher temperature than $271{\sim}278^{\circ}C$. The amethysts from Uljin Korea Amethyst can be distinguished from the synthetic amethyst on basis of the distinctive two and three-phases fluid inclusions. Furthermore, it is noticeable that Korea amethyst do not contain NaCl-bearing and $CO_2$-rich fluid inclusions unlike those compared to those from Eonyang and Samcheonpo deposits related to unmetamorphosed granitic rocks.

• Development and Reproduction
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• v.16 no.4
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• pp.271-277
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• 2012

The effects of ovulation induction in ussurian bullhead, Leiocassis ussuriensis, were investigated by treating ussurian bullhead with hCG, LHRHa, GnRHa, ovaprim, and pimozide. hCG was injected to ussurian bullhead at 0.75% NaCl, 5,000, 10,000, 20,000, and 30,000 IU, respectively. The ovulation inducement rates were 100% in 20,000 and 30,000 IU. Fertilization rates were 82.7% and 79.8%. Hatching rates were 59.4% and 57.2%. Ovulation time was between 16-19 hr The concentrations of LHRHa injected were 0.75 NaCl, 50, 100, 200, 300, and $300{\mu}g/kg$. The ovulation inducement rates were 100% in 300 and $400{\mu}g/kg$. Fertilization and hatching rates were 84.9% and 68.4% at $200{\mu}g/kg$. The times to ovulation were between 23 hr and 34 hr. Ovaprim of 0.75% NaCl, 1.0, 1.5, 2.0, 2.5 and 3.0 ml/kg were injected to the abdominal cavity. The ovulation inducement rate was highest at 2.0 and 3.0 ml/kg to 92% and ovulation time was between 27-38 hr. LHRHa concentrations of 0.75% NaCl, 50, 100, 200, 300 and $400{\mu}g$ were injected with pimozide ($1,000{\mu}g$). Ovulation inducement rate was 100% from 200 to 400 IU with pimozide. Ovulation time was 22-36 h. Fertilization and hatching rates were 88.9% and 70.4% in $200{\mu}g/kg$ with pimozide.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.727-737
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• 1992

The water chemical characteristics and age dating of springwater in Cheju island had been investigated. C_1, C_4, C_7, C_9 springwaters were not affected by seawater intrusion by TDS and electrical conductivity, relationship of Cl and tritium, Cl and HCO_3 ratio, and total hardness and pseudo hardness. In this case only C_7 springwater was evaluated tasty and healthy mineral springwater by Hahimoto's Mineral Balance Index. On the basis of the mean tritium content of rainfalls and springwater, the average residence time of it, were calculated. Considering the hydrogeologic and hydrochemical condition, completely mixed model seems to be very fit. It was obtained the result that C_9 group springwater (C_{10}, C_{12}, C_{14}) was 1.2 months, C_7 springwater was 5.6 months, and deep groundwater C_{17} was 4 years.

• Journal of Mushroom
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• v.11 no.4
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• pp.297-302
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• 2013

Pleurotus eryngii is one of the main export items in Korean mushroom industry. Whole mushrooms were packed with 30 um polypropylene anti-fog film without trimming. The range of package weight and oxygen permeability of film were 400 g and 2000 $c/m^2$, 24 h,atm, respectively. The anti-browning treatments were sprayed by 0.5%(w/w) solution of Sporix Sporix(Sodium polyphosphate and $ClO_2$ gas The weight loss ratio was increased with increasing shelf period and temperature. There were no big differences in weight loss ratio according to browning inhibitors. In case of $ClO_2$ treatment, the hardness and lightness of stem was showed higher than other treatment for shelf period. As results of freshness, the optimum browning inhibitor of P. eryngii was $ClO_2$ treatment and the shelf life was extended 36days at $10{\sim}15^{\circ}C$.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.123-127
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• 2009

본 논문은 국내 일부지역 주민의 건강행태가 위암발생에 영향을 미치는 요인들을 규명하기 위해 시행하였다. 이를 위해 서울에 소재한 한 종합병원에 위암관련 검진을 받기 위해 내원한 환자로 조직병리검사상 위암으로 확진받은 91명을 환자군으로 선정하였다. 대조군도 환자군과 동일한 기간, 동일한 병원 내과에 내원하여 동일한 방법으로 검진한 결과 위암에 속하지 않는 것으로 진단된 환자군과 연령, 성별에 대해 짝짓기하여 선정된 91명이었다. 자료수집은 2008년 12월 20일부터 2009년 1월 30일까지 설문과 면접조사의 방법을 병행하여 진행하였다. 연구결과 첫째, 취미활동량은 취미활동을 전혀 하지 않는 군에 비해 일일 평균 300kcal 미만 또는 그 이상의 열량을 소모하는 군에서 교차비가 각각 0.27과 0.33으로 위암발생 위험을 유의하게 감소시켰다(P<0.05). 둘째, 음주경험이 없는 군에 비해 있는 군(OR=1.85, 95% Cl=1.02-3.36), 총 음주기간이 30년 이상인 경우(OR=5.91, 95% Cl=1.78-19.95)에서 유의하게 높았다. 셋째, 탄음식을 주 3회 이상 섭취할 경우(OR=4.85 95% Cl=1.61-9.84), 짠음식의 섭취빈도가 주 3회 이상인 경우(OR=1.49 95% Cl=0.26-0.91) 위암발생과 유의하게 관련되었다. 넷째, 다중 로지스틱 회귀분석결과 위암발생에 영향을 미치는 요인은 월평균소득, 10년 전 BMI, 취미활동량, 알코올 섭취량, 탄류 및 짠류 섭취였다. 이러한 연구결과를 토대로 적당한 취미활동이 육체적 활동량의 증가뿐만 아니라 건강행동변화를 유도하여 결과적으로 위암예방 효과를 높일 수 있을 것이라 본다.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.174-179
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• 1992

Reaction of aniline and iodine in$CHCl_3,\;CH_2Cl_2 : CHCl_3$(1 : 1), and $CH_2Cl_2$ has been studied kinetically by using conductivity method, Pseudo first-order rate constants ($k_{obs}$) and second-order rate constants ($k_{obs}$/[aniline]) are dependent on the aniline concentration. Second-order rate constants obtained were increased with increasing aniline concentration. We analysed these results on the basis of formation of charge transfer complex as reaction intermediate. From the construction of react ion scheme and derivation of rate equation, we calculated equilibrium constants and activation parameters for the formation and transformation of charge transfer complex. The equilibrium constants were decreased by an increase in the dielectric constant of the solvent and the value is 1.7-3.7$M^{-1}$. The rate of transformation are markedly affected by the solvent polarity. ${\Delta}H^{\neq}$ is about 14.2kJ/mol, and ${\Delta}S^{\neq}$ is large negative value of -243J/mol K.

• Elastomers and Composites
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• v.39 no.1
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• pp.36-41
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• 2004

Solid polymer electrolytes were prepared by UV irradiation of the blends consisting of poly(ethylene oxide)(PEO), epoxy diacrylate(EDA) and LiClO_4$. Conductivities of the electrolyte films were measured as a function or blend composition, salt concentration and temperature. The electrolyte having the composition of poly(ethylene oxide) (70% by weight)/epoxy diacrylate (30% by weight) with mole ratio of 10 of ethylene $oxide/Li^+$ exhibited a high ionic conductivity of $1.2{\times}10^{-5} S/cm$ at $25^{\circ}C$. This blend is transparent and shows elastomeric properties. Morphological studies by means of differential scanning calorimetry, X-ray diffraction and polarized optical microscopy indicated that the cured epoxy chains in the blends inhibit the crystallization of poly (ethylene oxide) and thereby induce the blend systems to be completely amorphous in certain compositions.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.117-123
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• 2003

The results of field experiments with mesocosms on Lake Baikal, containing natural plankton assemblage, and laboratory experiments with microcosms containing Daphnia magna and Chlorella vulgaris demonstrated decrease of the structural exergy of the communities after the addition of allochtonous compounds peptone, diesel oil, o-diphenol, $CdCl_2$ to mesocosmsassemblage, phenol, $CoCl_2$ and $CuSO_4$ to micro-cosms. Structural exergy changes were more expressed than changes of components biomasses and total biomass of the community. Comparison of exergy content for benthos in cleanand affected by the discharges of Baikalsk Pulp and Paper Combine also showed sufficient docrease of structural exergy in polluted area. It points to the possibility of the use of structural exergy as ecosystem health reflecting parameter.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.456-460
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• 2004

Effects of sigma factor (${\sigma}^{B}$) on biofilm formation in Listeria monocytogenes 10403S and ${\sigma}^{B}-deficient$ sigB null mutant were studied under high osmotic and low temperature conditions. In brain heart infusion (BHI) medium containing 6% NaCl, wild type 10403S and ${\sigma}^{B}-deficient$sigB null mutant formed biofilms of $6.83{\pm}0.38\;and\;5.33{\pm}0.45\;log\;cfu/cm^{2}$, respectively. L. monocytogenes 10403S in BHI medium containing 6% NaCl formed 4.7 times larger biofilm than without NaCl. Culture of L. monocytogenes 10403S and sigB null mutant at $4^{\circ}C$ did not show any significant differences in biofilm formation. The results suggest biofilm formation is activated by ${\sigma}^{B}$ and NaCl, whereas not affected by low temperature stress in L. monocytogenes 10403S. More studies are necessary to determine biofilm formation mechanism in osmotolerant L. monocytogenes.