• Structural Engineering and Mechanics
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• 제8권3호
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• pp.285-297
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• 1999

A method is presented to find the location and magnitude of damage in a structure using data from dynamic tests. The test data include a combination of natural frequency measurements, taken before and after the occurrence of damage, and response measurements taken after damage. An algorithm is developed to identify localized increases in the flexibility of the structural members. Increases in flexibility are attributed to damage. The algorithm uses the sensitivity of the flexibility matrix to changes in the natural frequencies of the structure to identify the damage. A set of under determined equations is solved using an objective function which is derived from measurements of the system moments. Damage ranging from 10 to 60% increase in the flexibility of a member was successfully identified in a 50 d.o.f. structure, using a small number of natural frequency and velocity measurements.

• 약학회지
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• 제22권3호
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• pp.157-162
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• 1978

Total organic carbon(TOC) can be determined by means of combustion and flame ionization detector. The principle of string method is that a sample acidified to pH2 and transferred into combustion tube by string is oxidized with air. Another combustion tube method is that organic compounds are oxidized in the combustion tube charged with CuO and cobalt asbestos after the acidified sample is injected directly by microsyringe. Carbon dioxide evolved was reduced under specially treated nickel catalyst and hydrogen, the methane produced was detected by flame ionization detector. Linear relationship was found between concentration and the peak height by the string method. The peak area in the case of combustion tube method is in the range of 1-200ppm. The coefficient of variation by string method was 2.3% and that by combustion tube method was 1.8%. The lower detectable limit was about 10mol. Advantages of the latter are simplicity, sensitivity and reproducibility. TOC in contineous stream can also be determined automatically by means of the string method.

• Natural Product Sciences
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• 제24권4호
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• pp.241-246
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• 2018

The herbs of Lamium takesimense Nakai (Lamiaceae) is used to treat spasmodic and inflammatory disease. The four polar compounds, ecdysterone, isoacteoside, rutin and lamiuside C, were isolated and identified from the BuOH fraction of the L. takesimense MeOH extract. HPLC quantification was performed on a Capcell Pak C18 column ($5{\mu}m$, $4.6mm{\times}250mm$) with a gradient elution of $H_2O$ and 0.05% acetic acid in MeOH. The HPLC method was validated in terms of linearity, sensitivity, stability, precision, and accuracy. The quantitative level in plant material was determined as the following order: lamiuside C (4, 3.75 mg/g dry weight) > ecdysterone (1, 1.93 mg/g) > isoacteoside (2, 1.32 mg/g) > rutin (3, 0.97 mg/g).

• 대한방사선기술학회지:방사선기술과학
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• 제16권1호
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• pp.41-55
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• 1993

Recently, various screen film system have been introduced in diagnostic radiology. There are two kinds of screen film system : blue emitting $CaWO_4$ screen has been largely used in these days. However, it tends to be changed to use green emitting $Gd_2O_2S$ : Tb screen. In this study, photographic characteristics of $CaWO_4$ and $Gd_2O_2S$ : Tb screen were investigated with luminescence, spectroscopy. The morphology of $CaWO_4$ and $Gd_2O_2S$ : Tb were also observed by using scanning electron microscope. The result obtained were as follows : 1. There was small difference in the thickness of phosphor layers for the front and back screen of blue emitting system, but little difference in those of green emitting system. 2. There was no difference in the size of phosphor particles between the front and back screen for each screen. However, the particle size was different for the various kinds of screens. 3. The shape of phosphor particle was round with many faces for all the screens. 4. In the exposure of X-ray with the same intensity, luminescent intensity of a green emitting system was $6{\sim}7$ times larger than that of a blue emitting system. 5. The thickness of phosphor layers does not affect on the sensitivity of the screens exposed by X-ray.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.238-245
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• 2009

Pure culture experiments were conducted to assess the bacteriostatic and bactericidal effects of phlorotannins (PT) isolated from Ascophyllum nodosum (brown seaweed) on Escherichia coli O157:H7. In Exp. 1, one non-O157:H7 strain (25922) and three strains of E. coli O157:H7 (3081, EDL933 and E318N) were cultured in M9 medium with PT included at 0 (control), 25, 50 or $100{\mu}g/ml$ (n = 3). Bacterial growth was monitored by $OD_{600}$ at 0, 4, 6, 12 and 24 h, and by dilution plating at 0, 4, 6 and 24 h. All strains were inhibited (p<0.001) by PT to varying degrees. At 50 or $100{\mu}g/ml$, PT prevented growth of all four strains. At $25{\mu}g\;PT/ml$, growth of 25922, 3081, E318N and EDL933 was inhibited for 6, 12 and 24 h, respectively, but 25922 and 3081 resumed growth by 12 and 24 h. Direct plating confirmed bactericidal effects of PT on all four strains at $100{\mu}g/ml$, and on EDL933 and E318N at $50{\mu}g/ml$. In Exp. 2, strains 25922 and 3081 were incubated with no tannins or with $50{\mu}g/ml$ of PT, purified condensed tannins (CT) from Quebracho (Schinopsis balansaei), or purified tannic acid from Rhus semialata (Anacardiaceae) as hydrolysable tannins (HT). Strain 3081 was unaffected by HT or CT, but was completely inhibited (p<0.001) by PT at 4, 6 and 24 h. Strain 25922 was unaffected by HT, slightly inhibited by CT, and almost eradicated by PT at 4 and 6 h. Transmission electron microscopy revealed tannin-mediated alterations to bacterial cell walls. Phlorotannins from A. nodosum exhibit growth-inhibiting and bactericidal effects in vitro against the strains of E. coli O157:H7 investigated. Anti-E. coli efficacy of A. nodosum PT is superior to that of terrestrial tannins purified from Quebracho and from Rhus semialata.

• 천문학회지
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• 제37권4호
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• pp.159-169
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• 2004

This is a proposal to probe local part of the interplanetary dust (IPD) cloud complex and retrieve mean volume emissivity of the local IPDs at mid-infrared wavelengths. This will be done by monitoring, with Infrared Camera (IRC) aboard the ASTRO-F, the annual modulation of the zodiacal emission. In pointing mode of the ASTRO-F mission the spacecraft can make attitude maneuvering over approximately ${\pm}1^{\circ}$ range centered at solar elongation $90^{\circ}$ in the ecliptic plane. The attitude maneuvering combined with high sensitivity of the IRC will provide us with a unique opportunity observationally to take derivatives of the zodiacal emission brightness with respect to the solar elongation. From the resulting differential of the brightness over the ${\pm}1^{\circ}$ range, one can directly determine the mean volume emissivity of the local IPDs with a sufficient accuracy to de-modulate the annual emissivity variations due to the Earth's elliptical motion and the dis-alignment of the maximum IPD density plane with respect to the ecliptic. The non-zero eccentricity ($e_{\oplus}$= 0.0167) of the Earth's orbit combined with the sensitive temperature dependence of the Planck function would bring modulations of amplitude at least $3.34\%$ to the zodiacal emission brightness at mid-infrared wavelengths, with which one may determine the IPD temperature T(r) and mean number density n(r) as functions of heliocentric distance r. This will in turn fix the power-law exponent $\delta$ in the relation $T(r) = T_o(r/r_o)^{-\delta}$ for the dust temperature and v in $n(r) = n_o(r/r_o)^-v$ for the density. We discuss how one may de-couple the notorious degeneracy of cross-section, density, reference temperature $T_o$ and exponent $\delta$.

• 센서학회지
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• 제8권4호
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• pp.327-332
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• 1999

비표면적이 약 $200\;m^2/g$인 ${\gamma}-Al_2O_3$를 합성하여 얻은 ${\gamma}-Al_2O_3$ 담체에 Pd, Pt와 같은 귀금속 촉매를 첨가하여 접촉연소식 가스감지소자를 제작하였다. 제작된 센서는 최적동작을 위한 인가전압 1.75 V에서 소모전력은 약 500 mV였고, 부탄, 메탄 및 프로판 각각 100 %LEL에 대해서 약 120 mV의 높은 감도 특성을 보였다. 제작된 센서는 탄화수소 가스 농도에 대한 선형성, 재현성, 그리고 상대 습도변화에 대해서 안정된 감도 특성을 보여 주었다. 그리고 약 100일 동안 부탄 가스에 대해서 안정된 센서 감도 특성을 보여 주었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.436-439
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• 2002

Recently, It has performed that the basic research of the photoconductive material and the development and application of the digital radiograph detector which is divided into the direct and indirect method. The objective of this study investigate the effect of the electric characteristic about changing the composition of Arsenic in hybrid detector system for compensating a defect of conventional. We fabricated samples using the amorphous Selenium and Arsenic alloy with various concentrations of the Arsenic{seven step 0.1%, 0.3%, 0.5%, 1%, 1.5%, 3%, 5%). And using EFIRON optical adhesives the formed multi-layer$(Gd_{2}O_{2}S(Eu^{2+}))$ composed phosphor layer. X-ray and light sensitivity was measured to study x-ray response characteritics. As results, highest value was measured as output net charge and SNR were $315.7pC/cm^2/mR$ and 99.4 at 0.3%As doping ratio.

• 통상정보연구
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• 제17권1호
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• pp.241-264
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• 2015

본 연구는 국제산업연관표의 전후방연쇄효과를 이용하여 지난 15년간 한 중 일 3국간 산업의존도 변화를 살펴본 것이다. 분석방법으로는 아시아국제산업연관표를 이용하여 한 중 일 3국간 산업연관모형을 만든 후 영향력 계수와 감응도 계수를 분석하는 것이다. 연구결과 동북아 지역경제에서 중국의 영향력이 상승하고 일본의 영향력이 하락하는 가운데 한 중 간의 산업연관성이 매우 긴밀해지고 있다는 것이 확인되었다. 또한, 한 중 일 3국은 자국내 산업에 대한 영향력과 의존도는 감소하면서 상대국 산업에 대한 영향력과 의존도는 확대되는 산업공동화 현상을 경험하고 있는 것으로 나타났다. 그리고 상호의존도를 산업별로 살펴보면 주로 석유, 기계, 수송 장비, 무역 운송, 서비스, 공공행정 등 몇몇 산업부문에서 전후방 연쇄효과가 집중되고 있음을 알 수 있었다. 이밖에 한 중 일 3국은 서비스산업에서 전후방연쇄효과가 증가되어 왔는데, 이는 3국 무역에서 서비스의 의존성과 비중이 점점 증가하고 있다는 것을 의미한다.

• 한방비만학회지
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• 제13권2호
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• pp.74-83
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• 2013

Objectives: This study was performed to evaluate the effects of fermented lotus extracts on the inhibition of differentiation in 3T3-L1 preadipocytes. Methods: Extracts of lotus leaf and lotus root were fermented using 4 different probiotics separately, including Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium breve, and Bifidobacterium longum. Inhibition of preadipocyte differentiation was examined by Oil red O dye staining. Expressions of adipogenic transcription factors including CCAAT/enhancer binding proteins (C/$EBP{\alpha}$) and peroxisome proliferators-activated receptor ${\gamma}$ ($PPAR{\gamma}$) were analyzed by real time polymerase chain reaction and Western blotting analysis. Results: Fermented lotus extracts inhibited adipogenic transcription factors by inhibiting preadipocytes differentiation. All of the groups fermented by 4 kinds of probiotics showed reduction in Oil Red O dye staining. Bifidobacterium breve showed the most effective inhibition of C/$EBP{\alpha}$. Bifidobacterium breve and Bifidobacterium longum showed the best downregulation of $PPAR{\gamma}$ expressions compared with the control and the unfermented lotus group. Conclusions: Fermented lotus extracts showed significant effects on inhibition of preadipocyte differentiation in 3T3-L1 preadipocytes showing correlation with insulin sensitivity and lipid metabolism related with obesity.