본 연구에서는1축 회전판형 한외여과막 모듈의 순수 투과율 예측모델과 기름 에멀션의 분리 특성 및 투과율 예측모델을 유도하였다. 1축 RDM은 한외여과막(UOP사, 직경 0.22m)으로 제작된 회전판막을 장착하여 25℃ 에서 압력, 각속도(ω ), 농도 변화에 따라 분리특성을 조사하였다. 회전판막의 각속도가 0에서 52.36rad/s로 증가할수록 회전판내 유체가 받는 원심력에 의한 압력 강하와 분리막 표면의 미끄럼 흐름에 의한 압력 강하로 순수 투과율은 최대 각속도에서 3.9% 감소하였다. 원심력과 미끄럼 흐름에 의한 압력 강하는 선속도(ωr )의 자승에 비례하였다. 회전판의 각속도가 52.36에서 2.62rad/s로 감소할 때 5% 절삭유의 투과율은 30.16% 감소하였고 농도가 낮을수록 막회전과 투과율에 미치는 영향은 적었다. 절삭유의 투과율(J; kg/m2ㆍs )은 회전에 의한 압력 강하를 고려한 유효압력차(Delta PT ; Pa), 벌크농도(CB ; %), 선속도(ω r; m/s) 등에 영향을 받으며 실험 결과에 저항 모델을 적용하여 다음과 같은 식을 유도하였다.

The physical properties of the flux factor K and its application are discussed in connection to the high amplification events. The effects due to random motions of stars in a foreground galaxy are examined in the frame work of moving caustics of gravitational microlenses.

Vertical distribution of interstitial Cu^(++) contents of bottom sediments, upward benthic flux and oxidation zone flux are measured from the sediments at a site of Gongjichon area, Lake Uiam. Interstitial Cu^(++) contents show a pronounced maximum at water-sediment interface, and linear decrease to the depth of 9 cm at which anoxic sediments begin to occur, which cause an upward benthic flux and oxidation zone flux of interstitial Cu^(++). The depths of minimum interstitial Cu^(++) content show those of maximum sediment Cu^(++) content from which we presume the vertical flux and inter-species exchange of elements in the sediment layer. In oxic zone, interstitial Cu^(++) contents correlate very well with total organic matters, and total organic matters with mean particle size. These facts suggest that the amount of interstitial Cu^(++) contents are mainly controlled by the amounts of organic matters supplied to the sediment when they were deposited rather than by the post-depositional processes in the sediment layers. Upward benthic flux to the overlying water and oxidation zone flux to the interface of oxic and anoxic zone are 5.2×10^(-9)μ㏖·㎝^(-2)·sec^(-1), 0.1×10^(-9)μ㏖·㎝^(-2)·sec^(-1), respectively.

The transverse velocities of the gravitational lens system (galaxy plus a 'disturbing star') and their dependences on unkown properties of the source and the deflecting object are discussed. We have derived an analytic expression for the transverse velocity in terms of the velocities of the light source, the gravitational lensing galaxy and the 'disturbing star', and the observer. The results are then further applied to an estimate of the expectation value of the absolute transverse velocity and of the probable time scales of flux changes of the double QSO 0957+561A, B.

Making use of a relation proposed by Wielen (1977), a new empirical relation between Call emission flux and stellar age is derived by analyzing Wilson and Woolley's spectroscopic data (1970) of late type main sequence stars (K0-M5) and kinematic properties of those stars given by Gliese (1969). The proposed relation shows that the emission flux excess of the Call H-K lines, F ′ k + F ′ k introduced by Linsky et al. (1979) decreases with stellar age τ as τ − 0.51 , consistent with the inverse square law as noted by Skumanich (1972).

본 논문은 비균일대칭성 열Flux인 수직사각 Duct내의 층류조합대류 열전달 효과를 해석하기 위하여 그 유동의 특성 지배 방정식 및 비균일 열Flux의 경계조건을 무차원화 시켜 이를 Galerkin's 방법에 의해 유한요소식으로 정식화하고 이에 대하여 R 하(a) 수 및 압력구배 변수에 대해서 Duct 내의 온도분포, 속도분포 및 Nusselt 수의 값을 계산하였고 온도분포를 열 Flux가 일정 및 없는 경우와 비교하였으며 또 닥트내의 열전달 특성을 R 하(a) 수, 응력구배변수 및 Corner에 따른 변호경향을 조사하였다. 그 결과 1. 본 해석의 경계벽 온도분포 계산치와 유효자료들과의 비교에서 열 Flux가 일정 또는 없는 경우는 그 값이 일치하였다. 2. 닥트내의 온도분포와 Nusselt수의 값은 R 하(a) 수 및 압력구배 변수에 비례하여 증감하였다. 3. Nusselt수는 Corner에서 유속지연에 의한 온도분포의 특성 때문에 그 값이 감소하였으며 최대치는 0.7부근이었다

In this study, we analyzed seasonal variations in carbon dioxide fluxes, concentrations, and soil temperatures over three years in unvegetated tidal flats in the Beolgyo area. We also investigated the correlations between carbon dioxide fluxes and influencing factors. The average carbon dioxide flux was positive in summer and autumn but negative in winter and spring. A positive correlation was observed between carbon dioxide flux and soil temperature in spring whereas a negative correlation was noted in summer. In summer and autumn, as the soil temperature increased, the carbon dioxide flux decreased. In contrast, in spring and winter, as the soil temperature decreased, the carbon dioxide flux increased. Overall, this study reveals the significant influence of soil temperatures on carbon dioxide fluxes between the surface layer of the tidal flat and atmosphere.

In this paper, lysimeter was installed to analyze the moisture fluctuations on the surface of a forest. The weight of the soil was measured, and the moisture fluctuations were calculated through the difference in weight over time. The amount of dew condensation on the surface of the ground was about 2-7 mm. January experienced the most dew condensation (7.2 mm). It was found that about 43 mm of dew condensation was generated over one year. To analyze the characteristics of evapotranspiration in the forest, the evapotranspiration on the surface was measured by the lysimeter method and the evapotranspiration on the upper part of the canopy was measured by the eddy covariance method. These results were compared and analyzed. Until mid-October, the evapotranspiration of the forest was active, and the amount of evapotranspiration on the top of the canopy was higher than the amount on the surface. Thereafter, the amount of evapotranspiration on the top of the canopy decreased due to the lowering of temperature and net-radiation. The amount of evapotranspiration on the surface and above the canopy showed the same tendency.

강구조물에서는 노후화, 과대하중, 반복하중 등 다양한 요인으로 인해 손상이 발생하게 될 수 있는데, 이러한 손상의 초기대응이 늦을 경우 대형사고로 이어질 가능성이 있다. 이러한 이유로 손상을 조기에 탐지하기 위하여 여러 비파괴검사가 진행되고 있는데, 현 검사 기법으로는 대형 강구조물에 적용하기 어려운 단점이 있다. 따라서 본 연구에서는 연속체 형태의 구조물 진단에 주로 사용되는 누설자속 기반 비파괴검사 기법을 적용하였다. 누설자속 기반 비파괴검사 기법의 가능성을 확인하기 위해, 강판 시편에 각각 다른 깊이의 인위적인 손상을 가하였다. 이후 제작한 센서헤드를 시편에 접근시켜 누설자속의 크기를 측정하였다. 이로부터 추출된 신호에 신호처리를 하여 강판의 손상을 검출하였다.

In order to analyze the sensitivity of carbon dioxide flux by soil temperature in the grassplot, carbon dioxide flux and soil temperature were observed 24 times from March, 2010 to March, 2011 at nine sites in the grassplot. The average of CO2 in the grassplot is 2.2~36.7℃, the highest in August, the lowest in January, and the average of carbon dioxide flux is 12~1479 mgCO2·m-2·hr-1, and the carbon dioxide emission from the grassplot to the atmosphere was 10 times higher in summer than in winter. The temperature response coefficient estimated by the exponential function of carbon dioxide flux according to soil temperature was ranged from 0.1065 to 0.1274, and the increase tendency of CO2 flux with soil temperature was linear at 0~2 0℃and exponential at 20~40℃. The Q10 values for each of nine observation sites on the grassplot was in the range of 2.901 ~ 3.575, and the Q10 value using the total data observed in the lawn was estimated to be 3.374. In the homogeneous grassplot area, the average of Q10 values by observation point and the Q10 value by the total data were estimated similarly.

본 연구에서는 인공위성 및 재분석 자료인 Global Land Data Assimilation System (GLDAS), Global Land Evaporation Amsterdam Model (GLEAM), MOD16의 실제증발산량 산출물을 활용하여 한국수자원조사기술원(Korea Institute of Hydrological Survey, KIHS)에서 관리하고 있는 청미천(cheongmicheon farmland site, CFK)과 설마천(seolmacheon site, SMK) flux tower에서 검증하였고, Triple collocation (TC) 방 법을 활용하여 자료간의 불확실성 및 상관성분석을 수행하였다. 플럭스타워와의 검증 결과에서는 전반적으로 GLEAM>GLDAS>MOD16순으로 좋은 결과를 나타내었으며, 세가지 산출물의 조합(S1: flux tower vs. GLDAS vs. MOD16, S2: flux tower vs. GLDAS vs. GLEAM, S3: flux tower vs. GLEAM vs. MOD16)을 통한 TC 결과에서는 청미천(설마천)에서 GLEAM>GLDAS>MOD16>flux tower (GLDAS>GLEAM>MOD16>flux tower)순으로 좋은 결과를 나타내었다. TC 분석 결과에서 Flux tower의 error variance와 correlation coefficient가 상대적으로 좋은 결과를 나타내지 못하였으므로, 한반도 지역에서 인공위성과 재분석 자료(GLDAS vs. GLEAM vs. MOD16)만을 활용하여 TC를 적용하였다. 그 결과, GLDAS 와 GLEAM이 한반도 영역에서 낮은 error variance 와 높은 correlation coefficient를 나타낸 반면, MOD16의 경우, 농지에서 낮은 correlation coefficient과 높은 error variance를 나타내었다.

In this study, a magnetic flux leakage (MFL) method that is known as a suitable non-destructive evaluation (NDE) method for continuum ferromagnetic members was applied to detect the various types of local damages of the steel wire ropes. 3types of artificial damages, such as cutting, corrosion and compression, were formed on wire rope specimen. A multi-channel MFL sensor head that can maintain the constant lift-off was fabricated to scan the wire rope specimen. The fabricated MFL sensor head measured the magnetic flux signals from the three types of damaged specimens. The capability of damage detection according to damage type was verified from the measured MFL signals from each type of damage. And, the characteristics of the MFL signals were compared and analyzed by type of damage.

Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.