• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.379-384
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• 2001

This Paper Presents field application test results of mass concrete using super retarding agent. The field test was carried out at mat foundation(thickness 1m) of newly constructed information center of Chongju university. Placing lift composed of 2 layers, and each layer is 50cm. Fly ash and flowing method is also applied. Difference of setting time of concrete between with super retarding agent and without super retarding agent is considered. Concrete without super retarding agent is placed at upper layer and with super retarding agent at lower layer According to test results, the reducing method of hydration heat considering difference of setting time with super retarding agent can reduce the highest temperature about 3~4$^{\circ}C$, and delay the peak time about 3~4days. Compressive strength using super retarding agent is somewhat higher than that of normal concrete. Accordingly, super retarding agent does not affect the strength development.

• 천문학회보
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• 제41권2호
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• pp.56.1-56.1
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• 2016

A low-mass star-forming region, L1251B, is an excellent example of a small and nearby group of protostellar objects. L1251B has been mapped spectroscopically with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. IRS has provided mid-IR emission lines (e.g., [Fe II], [Ne II], and ro-vibrational H2) and absorption features of CO2 and H2O ice in studying the physical state of the ionized gas and the material residing in the circumstellar environments. We will present the distribution of outflows and ice components in L1251B.

• Journal of Pharmaceutical Investigation
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• 제37권2호
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• pp.79-84
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• 2007

This study was aimed to establish analytical method of Bi to develop a guideline of the bioequivalence test of tripotassium dicitrato bismuthate (TDB). For this purpose, a simple, specific and sensitive inductively coupled plasma-mass spectrometry (ICP/MS) method were developed and validated in human plasma. Various concentrations of bismuth standard solution (0-25ng/mL) were prepared with distilled water and human blank plasma. To 10mL of the volumetric flasks, 2mL of blank plasma was added with 8ml of distilled water. Bi standard solution was added to prepare the calibration samples and injected into ICP-MS. The plasma samples obtained from volunteers given 3 tablets of bismuth (total 900mg as TDB) were analyzed as described above. As a result, the coefficients of variation were <20% in quantitation limit (0.2 ng/mL) and <15% at the rest of concentrations. The stability test by repeated freezing-thawing cycles showed that the samples were stable only for 24hr. The stability tested for samples with a short-term period of storage at room temperature and pre-treatment prior to the analysis showed very stable over 24hr. In 8 healthy Korean subjects received Denol tablets at the dose of 900mg bismuth, AUC, $C_{max},\;T_{max}$ and half-life $(t_{1/2})$ were determined to be $198.33{\pm}173.78 ng{\cdot}hr/mL,\;64.48{\pm}27.06 ng/mL,\;0.52{\pm}0.21 hr,\;and\;5.15{\pm}2.67 hr$, respectively, from the plasma bismuth concentration-time curves. In conclusion, the method was suitable for the determination of bismuth in human plasma samples and could be applied to bioequivalence test of bismuth tablet.

• 천문학회지
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• 제55권4호
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• pp.123-130
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• 2022

We present the analysis of a planetary microlensing event OGLE-2019-BLG-0362 with a shortduration anomaly (~0.4 days) near the peak of the light curve, which is caused by the resonant caustic. The event has a severe degeneracy with ∆𝜒² = 0.9 between the close and the wide binary lens models both with planet-host mass ratio q ≃ 0.007. We measure the angular Einstein radius but not the microlens parallax, and thus we perform a Bayesian analysis to estimate the physical parameters of the lens. We find that the OGLE-2019-BLG-0362L system is a super-Jovian-mass planet $M_p=3.26^{+0.83}_{-0.58}M_J $ orbiting an M dwarf $M_h=0.42^{+0.34}_{-0.23}M_{\odot}$ at a distance $D_L=5.83^{+1.04}_{-1.55}kpc$. The projected star-planet separation is ${\alpha}_{\bot}= 2.18^{+0.58}_{-0.72}AU$, which indicates that the planet lies beyond the snow line of the host star.

• 에너지공학
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• 제15권4호
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• pp.243-249
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• 2006

본 실험적 연구는 슬릿휜-관열교환기의 냉매측 압력강하에 대하여 수행하였다. 응축기의 설계조건에서 미세휜관내 냉매 R22와 R134a의 압력강하에 대한 실험데이터와 앞서 제안한 상관관계식과 상호 비교하였다. 실험은 냉매 R22와 Rl34a의 응축기 입구온도 $60^{\circ}C$, 질량유속 $150{\sim}250\;kg/m^{2}s$ 범위에서 수행하였다. 공기의 유입조건은 건구온도 $35^{\circ}C$, 상대습도 40%이며, 공기유속의 범위는 $0.68{\sim}1.43\;m/s$이다. 실험결과 응축기의 과냉도 $5^{\circ}C$ 조건에서 R134a의 압력강하는 R22보다 $22{\sim}22.6%$ 높게 나타났으며, 냉매의 질량유속 $200{\sim}250\;kg/m^{2}s$의 범위에서 실험으로부터 측정한 R22와 Rl34a의 압력강하는 예측결과와 ${\pm}20%$내에 일치하였다.

• 한국식품과학회지
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• 제41권4호
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• pp.458-463
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• 2009

설사성패류독의 신속정밀 분석조건 확립을 위하여 LC-MS/MS를 사용하여 이동상, 분석용 column 및 collision energy 등을 변화시키면서 시험하였다. 50 mM formic acid와 2 mM ammonium formate가 함유된 acetonitrile 수용액을 이동상으로 사용하였을 때 OA와 DTX1이 검출되었다. Collision energy는 독소 성분에 따라 달리하는 것이 다성분 동시분석에 적합하였으며 OA와 DTX1 고유의 fragment ion들은 48 V 정도에서 최적의 intensity로 확인되었다. Column의 종류에 따라서는 $C_8$ column의 경우 OA, DTX1, DTX3, PTX2 및 YTX 모두 검출 가능하였으나 실제 검출 대상이 OA와 DTX1인 경우에는 일반적으로 사용되는 $C_{18}$ column도 적합한 것으로 확인되었다. 본 연구에서 확립한 LC-MS/MS 분석 조건의 검출한계는 OA와 DTX1 모두 1 ng/g, 정량한계는 각각 3 ng/g이었고, 표준독 성분을 첨가한 시료에서 process efficiency는 굴의 경우 91-118%, 진주담치에서는 96-117%이었고, matrix의 영향은 거의 없었다. 마우스 시험에서 양성을 나타낸 시료를 LCMS/MS법으로 분석한 결과, 일부 시료에서만 OA 및 DTX1이 검출되어 두 시험법의 독성은 일치하지 않았으며 LC-MS/MS법은 마우스 시험법보다 하루 이상 분석시간을 단축할 수 있었다.

• Structural Engineering and Mechanics
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• 제69권1호
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• pp.95-104
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• 2019

The Standard ASCE 61-14 proposes the Substitute Structure Method (SSM) as a Nonlinear Static Procedure (NSP) to estimate nonlinear displacement demands at the center of mass of piers or wharves under seismic actions. To account for bidirectional earthquake excitation according to the Standard, results from independent pushover analyses in each orthogonal direction should be combined using either a 100/30 directional approach or a procedure referred to as the Dynamic Magnification Factor, DMF. The main purpose of this paper is to present an evaluation of these NSPs in relation to four wharf model structures on soil conditions ranging from soft to medium dense clay. Results from nonlinear static analyses were compared against benchmark values of relevant Engineering Design Parameters, EDPs. The latter are defined as the geometric mean demands that are obtained from nonlinear dynamic analyses using a set of 30 two-component ground motion records. It was found that SSM provides close estimates of the benchmark displacement demands at the center of mass of the wharf structures. Furthermore, for the most critical pile connection at a landside corner of the wharf the 100/30 and DMF approaches produced displacement, curvature, and force demands that were reasonably comparable to corresponding benchmark values.

• BMB Reports
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• 제33권3호
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• pp.234-241
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• 2000

A new type of the human TSA homologous gene was cloned from a HeLa cell cDNA and characterized. The gene product consists of 161 amino acids with a molecular mass of 16,900. The TSA homologous protein, as a new 6th member of the human TSA (hTSA VI), exerted a thioldependent peroxidase activity with the use of thioredoxin system as a physiological electron donor. The values of $V_{max}/K_m$ of hTSA VI for $H_2O_2$ and t-butyl hydroperoxide (t-BOOH) were calculated as $5.53{\times}10^{-2}$ and $3.70{\times}10^{-2}$, respectively. This implies that hTSA VI is a peroxidase, which reduces $H_2O_2$ and t-BOOH. The mutation of $Cys^{47}$ to serine resulted in a complete loss of the peroxidase activity. This suggests that $Cys^{47}$ acts as a primary site of catalysis. The analysis of the tryptic digest derived from hTSA VI revealed that the $Cys^{47}$ exists as a free thiol form. Taken together, these results suggest that the TSA homologous protein is a new type of the human family, which exerts thioredoxin-linked peroxidase activity toward $H_2O_2$ and alkyl hydroperoxide.

• 에너지공학
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• 제15권3호
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• pp.166-173
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• 2006

본 연구에서는 상용 냉동 공조기기에서 사용하고 있는 휜-관 열교환기에서 R22와 이의 대체냉매로 채용하고 있는 R134a 압력강하와 열전달 특성에 대해 실험적으로 연구하였다. 실험은 입구온도 $60^{\circ}C$, 질량유량 $150,\;200,\;250\;kg/m^{2}s$의 범위에 대해 수행하였다. 이때 공기의 유입조건은 전구온도 $35^{\circ}C$, 상대습도 40%, 공기유속은 $0.68{\sim}1.6m/s$이다. 실험 결과 응축기 출구의 과냉도를 $5^{\circ}C$로 유지한 경우 Rl34a의 필요공기유속은 R22보다 5.9%작게 나타났으며, R134a의 압력강하는 R22보다 $18.1{\sim}20.4%$의 범위 내에서 크게 나타났다.

• 대한화장품학회지
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• 제33권2호
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• pp.79-86
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• 2007

본 연구는 연교 추출물과 연교 추출물에서 분리한 활성물질의 멜라닌 생성 억제 효과에 관한 것이다. 연교 추출물은 $0.1{\sim}1.0%$ (v/v)에서 세포독성이 없는 것을 확인하였으며 이를 바탕으로 멜라닌 생성억제 실험결과 1.0 %에서 $63.1{\pm}3.1%$ 저해 효과를 확인하였다. 또한 활성물질을 분리하여 $^1H-NMR,\;^{13}C-NMR$, Mass analysis 등의 기기분석 결과 리그난 계열의 활성물질인 4-[(3,4-Dimethoxyphenyl)methyl)]dihydro-3-[(4-hydroxy-3-methoxyphenyl)methyl]-2(3H)-furanone (arctigenin)으로 동정되었다. 활성물질에 대한 멜라닌 저해효과를 확인한 결과 농도 의존적으로 $3.0{\mu}g/mL$에서 $52.7{\pm}3.1%$를 저해하는 것을 확인하였다. 또한 연교 추출물을 3 % 함유한 크림의 미백효과에 대한 임상실험을 진행한 결과 전문의의 육안평가와 기기평가 모두 통계적으로 유의한 결과를 얻을 수 있었다. 결론적으로 연교 추출물은 미백 효능을 갖는 화장품 소재로서의 개발 가능성이 클 것으로 기대된다.