• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.1-8
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• 2015

Wind power systems have gained much attention due to the relatively high reliability, good infrastructures and cost competitiveness to the fossil fuels. Advances have been made to increase the power efficiency of wind turbines while less attention has been focused on structural integrity assessment of structural sub-systems such as towers and foundations. Among many parameters for integrity assessment, the most perceptive parameter may be the induced horizontal displacement at the hub height although it is very difficult to measure particularly in large-scale and high-rise wind turbine structures. This study proposes an indirect displacement estimation scheme based on the combined use of inclinometers and accelerometers for more convenient and cost-effective measurements. To this end, (1) the formulation for data fusion of inclination and acceleration responses was presented and (2) the proposed method was numerically validated on an NREL 5 MW wind turbine model. The numerical analysis was carried out to investigate the performance of the propose method according to the number of sensors, the resolution and the available sampling rate of the inclinometers to be used.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1028-1034
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• 1999

Poly(lactic acid) is expected to be one of the most promising biodegradable polymers. However, the high molecular weight polymer could be obtained by ring-opening polymerization process conventionally, which raises the production cost and decreases the final yield. In this study, linear and star-shaped poly(L-lactic acid)s were prepared by direct solution polycondensation method and their physical and thermal properties were examined. Tin compounds were found to be effective catalyst for the preparation of high molecular weight polymers. When 0.2g (0.5 wt % of monomer) of $SnCl_2$ and 100 mL of p-xylene were used, the polymer yield and molecular weight were relatively high. As a means to obtain higher molecular weight polymer easily in the direct polycondensation system, dipentaerythritol(dipet) or pentaerythritol(pet) was introduced as a multifunctional branching monomer to provide a star-shaped poly(lactic acid). Moderately high molecular weight polymers with the inherent viscosity values up to 1.14 dL/g(weight-average molecular weight of about 140000 by GPC) were obtained and could be cast strong and transparent films.

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.36-40
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• 1981

with the chemical equilibrium formula by Hailwood and Horrobin, $$m=a{\cdot}((k_1k_2h)(1+k_1k_2h)^{-1}+(k_2h)_n-k_2h)^{-1})$$, based on absorption theory, monthly equilibrium moisture content(EMC) variations in southern Korea were predicted. The results were as follows: $$k_1=47370272{\cdot}10^{-7}+477345{\cdot}10^{-7}t-502775{\cdot}10^{-8}t^2$$ $$k_2=705940864{\cdot}10^{-9}+16979472{\cdot}10^{-10}t-555336{\cdot}10^{-11}t^2$$ $$w=2233848{\cdot}10^{-4}+694242{\cdot}10^{-6}+185328{\cdot}10^{-7}t^2$$ Here, it is temperature degrees in Celsius, k is the equilibria between hydrate water and dissolved water, k is the equilibria between dissolved water and the water vapour pressure surrounding atmosphere, w is the molecular weight of the polymer unit that forms the hydrate, h is the relative vapour pressure, And the formula was well agreed with the data when the constant values ${\alpha}$ were given to be 2200 in January, February, October, November and December, 1850 in March, April and May, 1920 June, July, August, and September seasonally.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.370-374
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• 2005

This study was carried out to investigate the effect of Gastrodiae rhizoma fractions on serum lipid profiles and atherogenic index (AI) in male S.D. rats fed a high fat diet supplemented with 10 : 2 : 1% (w/w) of lard, corn oil, and cholesterol during the entire 12-week experimental period. Forty-eight rats were randomly divided into four groups; A (low molecule), B (polysaccharide), C (protein) fractions of Gastrodiae rhizoma, respectively, and D (high fat diet as control). Body weight gain, diet intake and feed efficiency ratio did not differ significantly among the groups during the experimental period, but final body weight was on the average 44 g higher in control compared with the three groups of Gastrodiae rhizoma $(A{\sim}C)$. TC and TG levels of group B when compared with control were each decreased by an average of 21.5% and 39.6%, respectively. HDL-cholesterol level was markedly higher in group C than group A and B of Gastrodiae rhizoma. LDL-cholesterol levels of Gastrodiae rhizoma groups $(A{\sim}C)$ were significantly lower than control. AI was significantly lower in group C at 1.45 than the other two Gastrodiae rhizoma at $1.94{\sim}2.05$ and control of 2.12. From the findings, it is feasible for water soluble and high molecular weight components of Gastrodiae rhizoma like polysacchride and protein fractions to be considered as functional components for improving hyperlipidemia.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.257-266
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• 2015

This study introduce that we studied optimization and possibility of smoke spread prevention with air-curtain system in undersea tunnel named from Ho-Nam to Jeju line in domestic if a fire break out in train. To verify performance, air-curtain system is installed between rescue station platform and each door of passenger car to provide safety route to evacuator and we studied simulation model of various cases about 15 MW fire severity considering domestic specifications. As a result we verified the fact that CASE1(air jet with 15degree toward passenger car) and CASE 5 (air jet with 15degree toward passenger car and pressure air blast from cross passage) is best Smoke Spread Prevention and less inflow carbon monoxide. Through above results, we expect that air-curtain system is one of the facilities for fire safety and provide us safety platform route in undersea tunnel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.153-157
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• 2000

Hydrolysate which inhibit the Angiotensin I-converting enzyme (ACE) was prepared from mackerel muscle by pretense. The ACE inhibitory activity of mackerel muscle hvdrolysate (MMH) was $967 {\mu}g of IC_(50)$. ACE inhibitory peptides were isolated by ultrafiltration, gel permeation column chromatography (GPC), reversed phase column chromatography(RPC), reversed phasehigh performance liquid chromatography (RP-HPLC), and gel permeation high performance liquid chromatography (GP-HPLC) from the MMH. The amino acid sequence of the ACE inhibitory peptides was Tyr-Val-Ala. The $IC_(50)$ of this peptide for ACE from rabbit lung was $1.4 {\mu}M$.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1392-1400
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• 2017

Galactooligosaccharides (GOSs) are known to be selectively utilized by Bifidobacterium, which can bring about healthy changes of the composition of intestinal microflora. In this study, ${\beta}-GOS$ were synthesized using bifidobacterial ${\beta}-galactosidase$ (G1) purified from recombinant E. coli with a high GOS yield and with high productivity and enhanced bifidogenic activity. The purified recombinant G1 showed maximum production of ${\beta}-GOSs$ at pH 8.5 and $45^{\circ}C$. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the major peaks of the produced ${\beta}-GOSs$ showed MW of 527 and 689, indicating the synthesis of ${\beta}-GOSs$ at degrees of polymerization (DP) of 3 and DP4, respectively. The trisaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose, and the tetrasaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose. The maximal production yield of GOSs was as high as 25.3% (w/v) using purified recombinant ${\beta}-galactosidase$ and 36% (w/v) of lactose as a substrate at pH 8.5 and $45^{\circ}C$. After 140 min of the reaction under this condition, 268.3 g/l of GOSs was obtained. With regard to the prebiotic effect, all of the tested Bifidobacterium except for B. breve grew well in BHI medium containing ${\beta}-GOS$ as a sole carbon source, whereas lactobacilli and Streptococcus thermophilus scarcely grew in the same medium. Only Bacteroides fragilis, Clostridium ramosum, and Enterobacter cloacae among the 17 pathogens tested grew in BHI medium containing ${\beta}-GOS$ as a sole carbon source; the remaining pathogens did not grow in the same medium. Consequently, the ${\beta}-GOS$ are expected to contribute to the beneficial change of intestinal microbial flora.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.54-54
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• 1999

다이아몬드 합성시 질소 첨가는 Cn 화합물의 합성가능성을 비롯하여 다이아몬드의 질소 도핑, 성장 속도 및 결정성 변화 등 다양한 관점에서 중요한 의미를 가지고 있다. 본 연구에서는 다이아몬드의 일반적인 합성조건에서 질소를 첨가하여 합성된 막의 형상 및 상 변화에 대해 고찰하였다. 막은 다이아몬드 전처리시킨 Si 기판위에 microwave plasma CVD 장치를 이용하여 합성하였다. 유입되는 혼합가스(CH4+H2+N2)에서 N2 첨가량을 0-95%까지 변화시켰다. 이때 CH4 농도는 5%로 고정하였고, 합성온도는 90$0^{\circ}C$-115$0^{\circ}C$까지 변화시켰다. 이와 같이 합성된 막의 표면조직 및 성장 두께를 측정하기 위해 주사전자현미경을 이용하였다. 상의 분석은 Raman, XRD 및 TEM 분석을 이용하였으며, 조성분석을 위해 XPS 및 AES를 사용하였다. 질소 첨가량에 따라 합성된 막은 첨가하지 않은 경우에 다이아몬드 결정에서 시작하여 질소첨가에 따라 결정면이 깨지는 것으로 나타났다. 그러나 30%, 45%의 경우는 다시 결정면이 나타났다. 다량의 질소가 첨가되었을 때, 다시 결정면을 보이는 다이아몬드가 합성된 것은 매우 흥미로운 결과이다. 한편 질소와 메탄만의 기체하에서는 다시 결정면이 관찰되지 않았다. 이들 상의 구조는 XRD 및 TED 분석을 통해 모두 다이아몬드로 확인되었다. 기체내의 질소의 첨가에 관계없이 고상내에 질소는 확인되지 않았다. 따라서 이방법에 의한 CN 화합물의 합성은 힘든 것으로 보여진다. 이들 실험 결과를 근거로 온도 및 조성에 따른 기체의 열역학적 계산을 통하여 합성거동과의 연관성을 검토하였다. anode는 매우 높은 충전용량을 갖는데 첫 번째 방전시에 Li2O를 생성하여 비가역적 반응을 나타내고 계속되는 충방전 동안 Li-Sn 합금이 생성되어 2차전지의 가역적 반응을 가능하게 한다. SnO2 는 대기중에서 Li 금속보다 안정하기 때문에 전지의 제작 공정 및 사용 면에서 매우 우수한 물질이지만 아직까지 SnO2 구조적 특성과 전지의 충, 방전 특성에 대한 관계의 규명을 위한 정확한 정설은 제시되고 있지 못하다. 본 연구에서는 TFSB anode 물질로써 SnOx박막을 상온에서 여러 전도성 콜렉터 위에 증착하여 그 충, 방전 특성을 보고하였다. 증착된 SnOx박막의 표면은 SEM, AFM으로 분석하였으며 구조의 분석은 XR와 Auger electron spectroscope로 하였다. 충, 방전 특성을 분석하기 위하여 리늄 foil을 대극과 참조 전극으로 하여 EC:DMC=1:1, 1M LiPF6 액체 전해질을 사용한 Half-Cell를 구성하여 100회 이상의 정전류 충, 방전 시험을 행하였다. Half-Cell test 결과 박막의 구조, 콜렉터의 종류 및 Sn/O비에 따라 서로 다른 충, 방전 거동을 나타내었다.다. 거의 없었다. 5mTorr 일 때가 가장 좋았다.수 있음을 알 수 있었다. 그러므로, RNA바이러스의 하나인 BVDV의 viral replicon을 이용하여 다양한 종류의 포유동물 세포에 유전자 발현벡터로써 사용할 수 있음으로 post-genomics시대에 다양한 종류의 단백질 기능연구에 맡은 도움이 되리라 기대한다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품 개발에 따른 새로운 수요 창출과 수익률 향상, 기존의 기능성 안료를 나노(na

• Journal of Nutrition and Health
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• v.35 no.4
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• pp.439-445
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• 2002

This study was undertaken to investigate the inhibitory effect of prunus fume extracts on the growth of Hep G2 and HeLa cells. Prunus mums was extracted using the following solvents hexane, chloroform, ethylacetate, methanol, and hot water. The effect on the growth of each cancer cell line was examined by MTT (3-[4, 5-dimethylthiaeol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, cytotoxicity testing, and microscopic observation. The ethylacetate extracts of Prunus muse at the concentration of 250 $\mu\textrm{g}$/ml exhibited the greatest inhibitory effect on the growth of Hep G2 in the MW assay. In cytotoxicity testing, the treatment of the Hep G2 cells with ethylacetate extracts (1000 $\mu\textrm{g}$/ml for 72 hrs) destroyed 75% of the cells, and morphological changes were also observed. futhermore, the hexane extracts of Prunes muse at the concentration of 250 $\mu\textrm{g}$/ml exhibited the greatest inhibitory effect on the growth of HeLa cells in the MTT assay. The treatment of the HeLa cells with the hexane extracts (1000 $\mu\textrm{g}$/ml for 72 hrs) resulted in the destruction of 68% of the cells. Fibroblasts were not affected by either ethylacetate or hexane extracts of prunus muse.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.427-431
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• 1999

Copolyester resins for the coil coating process of aluminium and steel strip were synthesized and their thermal properties, molecular weight and solvent solution characteristics were examined. Copolyesters were obtained by two step reactions. The first step was to prepare bishydroxyethyl terephthalate (BHET), bishydroxyneopentyl terephthalate (BHNPT), bishydroxyethyl isophthalate (BHEI), bishydroxyneopentyl sebacate (BHNPS), bishydroxyneopentyl adipicate (BHNPA) and bishydroxyethyl adipicate (BHEA) oligomers by esterification reactions. The second step was the polycondensation reaction utilizing those oligomers to obtain relatively high molecular weight copolyesters (Mw = 30,000~59,000 g/mol) as measured by GPC. These copolyesters were amorphous polymers as shown by DSC without $T_m$ peaks probably due to the kink structure introduced by BHET oligomer and relatively large free volume by bulky BHNPT and BHNPS oligomers. The copolyester samples with half of BHET oligomer substituted by BHNPT while keeping BHEI (0.3 mole) and BHNPS (0.1 mole) ratio constant showed glass transition temperature above $40^{\circ}C$ and good solubility in toluene both at low ($-5^{\circ}C$) temperature and room temperature.