• 한국물환경학회지
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• 제31권6호
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• pp.653-664
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• 2015

TPLMS (Total water pollutant load management system) that is the most powerful water-quality protection program have been implemented since 2004. In the implementation of TPLMS, target water-quality and permissible discharged load from each unit watershed can be decided by water-quality modeling. And NPS (Non-point sources) discharge coefficients associated with certain (standard) flow are used on estimation of input data for model. National Institute of Environmental Research (NIER) recommend NPS discharge coefficients as 0.15 (Q₂₇₅) and 0.50 (Q₁₈₅) in common for whole watershed in Korea. But, uniform coefficient is difficult to reflect various NPS characteristics of individual watershed. Monthly NPS discharge coefficients were predicted and estimated using surface flow and water-quality from HSPF watershed model in this study. Those coefficients were plotted in flow duration curve of study area (Palger stream and Geumho C watershed) with monthly average flow. Linear regression analysis was performed about NPS discharge coefficients of BOD, T-N and T-P associated with flow, and R² of regression were distributed in 0.893~0.930 (Palger stream) and 0.939~0.959 (Geumho C). NPS Discharge coefficient through regression can be estimated flexibly according to flow, and be considered characteristics of watershed with watershed model.

• 천문학논총
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• 제14권1호
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• pp.33-37
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• 1999

We have constructed a synthetic spectrum of the 2.5 micron $C_2H$ bands and compared them with diminutive structures in the near-infrared spectra of Comets P/Halley and West (1976 VI). We found that the Q branches of the $C_2H$ bands coincide with two small emission peaks in the spectra of the comets. We undertook Monte Carlo simulations using observed emission intensities of $C_2$ and possibly $C_2H$ in Comet P/Halley in order to derive a lifetime range of $C_2H$ and a production rate at the time of observations of P/Halley. We obtained a $C_2H$ production rate of $1\times10^{27}\;sec^{-1}$ for P/Halley on December 20, 1985, assuming the 2.5 micron features are due to $C_2H$. We derived a very short lifetime (<100 seconds) of $C_2H$ at 1AU heliocentric distance, assuming that the only parent molecule for $C_2H$ and $C_2$ is $C_2H$. Using this short lifetime we were unable to fit our $C_2$ distribution model to $C_2$ distribution curves observed by O'Dell et al.(1988), because our curve shows a steep slope compared with the observed one. We conclude that there must be significant additional source(s) for $C_2H$ and $C_2$ other than $C_2H_2$.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.323-333
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• 2016

Background: Ovarian cancer remains a major worldwide health care issue due to the lack of satisfactory diagnostic methods for early detection of the disease. Prior studies on the role of serum cancer antigen 125 (CA125) and human epididymis protein 4 (HE4) in detecting ovarian cancer presented conflicting results. New tools to improve the accuracy of identifying malignancy are urgently needed. We here aimed to evaluate the diagnostic utility of tissue CA125 and HE4 gene expression in comparison to serum CA125 and HE4 in discriminating benign from malignant pelvic masses. Materials and Methods: One-hundred Egyptian women were enrolled in this study, including 60 epithelial ovarian cancer (EOC) patients and 20 benign ovarian tumor patients, as well as 20 apparently healthy women. Preoperative serum levels of CA125 and HE4 were measured by immunoassays. Tissue expression levels of genes encoding CA125 and HE4 were determined by quantitative real time polymerase chain reaction (qRT-PCR). The diagnostic performance of CA125 and HE4, measured either as mRNA or protein levels, was evaluated by receiver operating characteristic (ROC) curves. Results: The serum CA125+HE4 combination and serum HE4, with area under the curve (AUC) values of 0.935 and 0.932, respectively, performed significantly better than serum CA125 (AUC=0.592; P<0.001). Tissue CA125 and HE4 (AUC=1) performed significantly better than serum CA125 (P<0.001), serum HE4 (P=0.016) and the serum CA125+HE4 combination (P=0.018). Conclusions: Measurement of tissue CA125 and HE4 gene expression not only improves discriminatory performance, but also broadens the range of differential diagnostic possibilities in distinguishing EOC from benign ovarian tumors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.299-307
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• 2005

The 180 km/h Korean Tilting Train(TTX) which is now developing as a part of the Korean National R&D project, was elaborately designed. As the tilting trains run curve track with the $30\%$ higher speed than normal trains, the higher centrifugal and dynamic force are expected. Furthermore the complex tilting system increase the probability of failure. Therefore it is very important for tilting train to ensure safety against derailment under the various kind of failed condition in the middle of running as well as normal operating condition. The TTX train have the relatively high roll stiffness to improve the lateral ride comfort and to limit the roll displacement on the curve. But the higher roll stiffness increase the risk of derailment on the twisted track. This paper describes the study to review the safety against derailment caused by the wheel unloading on the severely twisted track. The worst combination of maximum cant change with maximum twist defect was established by numerical simulation. And also it was assumed that the air bag deflated and still the train run its speed limit. Those kind of assumption might be the worst case from the view point of wheel unloading derailment on the twisted track. The dynamic simulation was done by means of VAMPIRE S/W and non-linear transient analysis. We found that derailment quotients Q/P was only slightly influenced by track twist but the wheel unloading was greatly influenced. And we ascertained that the higher roll stiffness the higher wheel unloading. In case of air bag deflated situation, the wheel unloading reached up to $100\%$ which means the wheel lift or jumped. Therefore it was concluded that the design need to be improved to ensure the safety against derailment on the maximum twisted track in case of air bag deflated and tilting train's speed limit.

• Animal Bioscience
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• 제36권9호
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• pp.1336-1349
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• 2023

Objective: The study was conducted to screen differentially expressed miRNAs in sows at early pregnancy by high-throughput sequencing and explore its mechanism of action on embryo implantation. Methods: The blood serum of pregnant and non-pregnant Landrace×Yorkshire sows were collected 14 days after artificial insemination, and exosomal miRNAs were purified for high throughput miRNA sequencing. The expression patterns of 10 differentially expressed (DE) miRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR quantified the abundance of serum exosomal miR-192 in pregnant and control sows, and the diagnostic power was assessed by receiver operating characteristic (ROC) analysis. The target genes of DE miRNAs were predicted with bioinformatics software, and the functional and pathway enrichment analysis was performed on gene ontology and the Kyoto encyclopedia of genes and genomes terms. Furthermore, a luciferase reporter system was used to identify the target relation between miR-192 and integrin alpha 4 (ITGA4), a gene influencing embryo implantation in pigs. Finally, the expression levels of miRNAs and the target gene ITGA4 were analyzed by qRT-PCR, and western blot, with the proliferation of BeWo cells detected by cell counting kit-8 (CCK-8). Results: A total of 221 known miRNAs were detected in the libraries of the pregnant and non-pregnant sows, of which 55 were up-regulated and 67 were down-regulated in the pregnant individuals compared with the non-pregnant controls. From these, the expression patterns of 10 DE miRNAs were validated. The qRT-PCR analysis further confirmed a significantly higher expression of miR-192 in the serum exosomes extracted from pregnant sows, when compared to controls. The ROC analysis revealed that miR-192 provided excellent diagnostic accuracy for pregnancy (area under the ROC curve [AUC]=0.843; p>0.001). The dual-luciferase reporter assay indicated that miR-192 directly targeted ITGA4. The protein expression of ITGA4 was reduced in cells that overexpressed miR-192. Overexpression of miR-192 resulted in the decreased proliferation of BeWo cells and regulated the expression of cell cycle-related genes. Conclusion: Serum exosomal miR-192 could serve as a potential biomarker for early pregnancy in pigs. miR-192 targeted ITGA4 gene directly, and miR-192 can regulate cellular proliferation.

• 설비공학논문집
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• 제5권1호
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• pp.10-17
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• 1993

This paper describes the boiling heat transfer phenomena to be divided into three regions, nonboiling, nucleate boiling and burn-out in the impinging subcooled water jet system. In the nonboiling region, Nusselt number is a function of Prandtl number, Reynolds number and ${\Delta}T_{sub}/T_{ast}$ In the nucleate boiling region, the heat flux increases with increment of the nozzle exit velocity. But the degree of liquid subcooling does not affect the shape of the nucleate boilng curve. The dimensionless correlations can be expressed in the form of $q{\ell}/K_f{\Delta}T_{ast}=C(Bo{\cdot}C_p{\cdot}{\Delta}T_{sat}/Vo^2)^m{\cdot}(Re/We)^n$. The burn-out heat flux increases linearly with increment of the nozzle exit velocity, but independs of degree of subcooling and the supplementary water height.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.775-780
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• 2013

In recent years, a notebook like an ultrabook gets thinner. Its thickness causes problems in cooling fan performance, system installation condition, and so on. In this study, we installed a small turbofan in notebook system with very narrow gap in order to generate similar condition to a real product. Experiments were performed to measure the fan's performance and the flow and noise characteristics, its results were compared with computational ones. Prediction of P-Q curve using CFD showed under about 5% error in high flow rate and its trend was agreed with experimental one over the flow field. Experimental data to measure the noise at a distance of 100 mm from a rotation axis direction of an impeller corresponded well with computational ones of broadband and BPF noise. The noise experiments to measure at a distance of 100 mm from a rotation axis direction of an impeller corresponded well with computational ones of broadband and BPF noise. Especially, tip part of impeller blade and part of exit and bottom near in an analysis by a commercial program(FlowNoise).

• 분석과학
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• 제17권1호
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• pp.37-44
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• 2004

효모 Hansenula polymorpha 로부터 탄소원으로 0.5% 메탄올을 이용하여 알코올 산화효소를 대량 유도 발현하였다. 발현 유도된 Hansenula polymorpha 알코올 산화효소는 두 단계의 컬럼 크로마토그래피를 통하여 전기영동에서 단일밴드로 정제하였다. 정제한 효소는 주로 일차 지방족 알코올을 산화시키며, 에탄올에 대해 가장 높은 기질특이성을 보였다. 이 효소가 촉매하는 에탄올 산화반응의 최적 pH는 8.5 이였으며, 최적 온도는 $50^{\circ}C$를 나타내었다. 효소의 $T_m$ 값은 약 $52^{\circ}C$ 이었으며, $65^{\circ}C$에서도 완전히 불활성화 되지 않았다. 또한 효소는 변성제와 7주간의 비교적 장기간 보전에 대해서도 안정하였다. 이 효소는 알코올 측정을 위한 효소학적 방법 및 알코올과 알데히드의 공업적 생산에 이용될 수 있다.

• 천문학회지
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• 제55권1호
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• pp.1-9
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• 2022

We present the photometric properties of V608 Cas from detailed studies of light curves and eclipse timings. The light curve synthesis indicates that the eclipsing pair is an overcontact binary with parameters of ∆T = 155 K, q = 0.328, and f = 26%. We detected the third light ℓ₃, which corresponds to about 8% and 5% of the total systemic light in V and R bands, respectively. Including our 6 timing measurements, a total of 38 times of minimum light were used for a period study. It was found that the orbital period of V608 Cas has varied in some combination of an upward parabola and two periodic variations. The continuous period increase with a rate of +3.99 × 10^-7 d yr^-1 can be interpreted as a mass transfer from the secondary component to the primary star at a rate of 1.51 × 10^-7 M_⊙ yr^-1. The periods and semi-amplitudes of the two periodic variations are about P₃ = 16.0 yr and P₄ = 26.3 yr, and K₃ = 0.0341 d and K₄ = 0.0305 d, respectively. The most likely explanation of both cycles is a pair of light-traveling time effects operated by the possible presence of third and fourth components with estimated masses of M₃ = 2.20 M_⊙ and M₄ = 1.27 M_⊙ in eccentric orbits of e₃ = 0.66 and e₄ = 0.52. Because the contribution of ℓ₃ is very low compared to the estimated masses of two circumbinary objects, they can be inferred as very faint compact objects.

• 한국음향학회지
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• 제36권6호
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• pp.371-377
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• 2017

에어컨의 성능은 분리형 실외기의 냉각 성능과 밀접한 관련이 있으며, 그에 따라 대다수의 관련 선행 연구에서는 실외기 내부 축류팬의 단독 성능에 대한 연구를 진행하였다. 하지만 축류팬을 제외한 실외기 내부 여러 구성요소의 영향에 대한 연구는 부족한 실정이다. 따라서 본 논문에서는 여러 요소 중 팬 오리피스가 실외기 유동 성능에 미치는 영향을 수치적으로 분석하였다. 고정밀 유동장 해석을 위해 약 1800만 개의 격자로 구성된 가상 팬 테스터를 개발하고, V-LES의 일종인 비정상 RANS(Reynolds-averaged Navier-Stokes) 방정식을 CFD(Computational Fluid Dynamics) 기법에 기초하여 해석하였다. 수치 해석의 유효성을 확인하기 위해서 실험을 통해 측정한 실외기 시스템의 P-Q 곡선을 가상 팬 테스터를 사용한 수치 해석 결과와 비교하였다. 유효성을 검증한 수치 기법을 이용하여 실외기 유량 성능을 최대화할 수 있는 오리피스 형상 최적 설계를 수행하였다.