• ALGAE
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• 제29권3호
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• pp.197-201
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• 2014

This is the first recorded observation of Akashiwo sanguinea excreting mucilaginous substances from pores on the cell surface. Observations were from samples collected in the Caloosahatchee Estuary, Florida, USA during a bloom event, with densities of 672 cells $mL^{-1}$ of A. sanguinea, including 51 cells surrounded by mucous. Scanning electron microscopy observations revealed that the mucous was secreted from thecal pores on the cell surface. The potential significance of mucous production is discussed.

• 천문학회보
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• 제35권1호
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• pp.28.1-28.1
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• 2010

Ground-based solar observations have several merits such as wider field of view and higher time cadence than those of satellite observations. The Domeless Solar Telescope of Hida Observatory is designed to acquire solar surface images at the highest possible spatial resolution using two types of spectrographs: a vertical spectrograph with the highest wavelength resolution in the world, and a horizontal spectrograph that can take images of the sun in multi-wavelength over the entire visible solar spectrum. The temporal variation of fine features such as chromospheric grains in the supergranulation cells and facular points in the network region has been obtained using DST Ca II K lines compared with Hinode Ca II H lines. This analysis is expected to provide a fundamental tool for research of diverse phenomena on the solar surface.

• 한국환경과학회지
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• 제7권5호
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• pp.639-645
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• 1998

A Jump model was evaluated for the calculation of hourly mixing height and mean potential temperature within the height. The Sump model was modified for estimation of downward heat fluxes by mechanical convections and surface heat fluxes. The surface heat fluxes were estimated from routine weather data such as solar radiation and air temperature. Total of 8 upper-air data observed at 0000UTC and 0600UTC in Osan station during April 23 to 26, 1996 were analyzed, and compared to the model results in detail. The calculated mixing heights and potential temperatures within the height were comparable to the observations, but some differences were showed. The calculated mixing heights were generally higher than observations. And, when variations of wind directions were large, the large difference of potential temperature was occurred. From the results, it was important to note that vortical motions and advections of air masses would affect to the growth of the mixing height.

• Ocean and Polar Research
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• 제24권2호
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• pp.135-146
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• 2002

The upper ocean in the western equatorial Pacific warm pool during TOGA-COARE IMET IOP was simulated using a one-dimensional turbulence closure ocean mixed-layer model, which considered recent observations, such as the remarkable enhancement of turbulent kinetic energy near the ocean surface. The shoaling/deepening of the mixed layer and warming/cooling subsurface water in the model were in reasonable agreement with the observations. There was a significant improvement in simulating the cooling trend of the sea surface temperature under a westerly wind burst with heavy rainfall over previous simulations using bulk mixed-layer models. By contrast the simulated sea surface salinity (SSS) departed significantly from the observed SSS, especially during a westerly burst and the subsequent restratification period, which might be due to 3-D control processes, such as downwelling/upwelling or advection.

• 천문학회보
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• 제36권2호
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• pp.83.2-83.2
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• 2011

The emergence of a magnetic flux tube (flux emergence) is a process of transporting magnetic field from the solar interior to the atmosphere. This process naturally produces bipolar structure at the surface, in which emerging field lines simply connect opposite polarities, while observations suggest that the surface distribution of magnetic field is more complicated than a simple bipole. This study is aimed at solving this apparent mismatch between the model and observations, showing how the surface distribution changes from a simple bipolar distribution to a quadrupolar-like one, where a half-turn rotation of the polarity inversion line plays an important role. We explain the physical reason of this half-turn rotation and also discuss a possible configuration of filament magnetic field in terms of the quadrupolar-like structure formed via flux emergence.

• ALGAE
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• 제29권2호
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• pp.121-126
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• 2014

Cephaleuros parasiticus and C. virescens were collected from Kerala and Tamil Nadu, India. Macroscopic and microscopic features were observed and their comparative features were discussed. The lesions of C. parasiticus occur on the upper and lower leaf surfaces although zoosporangia form only on the lower surface. The thalli grow subepidermally and intramatrically, causing necrosis of whole leaf tissue. On the other hand C. virescens thalli develop on the upper surface and zoosporangia form on the upper surface, the thalli grow subcuticularly, and only the host epidermal and palisade cells are necrosed. Syzygium aromaticum and Polyalthia longifolia are new host plants of C. parasiticus and C. virescens, respectively.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.137-146
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• 2007

This study is about the passive cooling effects of three outdoor solar shading facilities as trees, pergola with wistaria vine and membrane shading structure, which are expected to provide cool spots in the summer. Field observations of measuring thermal environment of selected facilities is executed. Thermal environment measuring was categorized as short wave radiation, long wave radiation, net radiation, globe temperature, surface temperature measured by infrared camera. Heat transfer mechanism is analyzed with overall data from field measurement. Results from this study are as below; 1) Radiation balance measured on shaded surface under membrane shading structure was 17%($86W/m^2$) of the unshaded surface radiation balance($511W/m^2$). 2) Surface temperature comparison between vegetation and membrane of the shading structure is performed at 3 o'clock in the afternoon. Surface temperature of vegetation was same as air temperature and that of membrane was $5^{\circ}C$ higher than air temperature. Vegetation transpiration is considered as the causing factor which make those differences. 3) Results from this study could be used as fundamental data for reducing heat island phenomena and continuos research on this subject would be needed.

• 천문학회보
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• 제43권2호
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• pp.45.1-45.1
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• 2018

We present observational evidence of the surface homogeneity on Phaethon based on the time-series multi-band photometry and spectrometry. The observations of Phaethon were conducted in Nov.-Dec. 2017. We confirmed that Phaethon is a B-type asteroid, as was previously known, and its rotational color variation was not detected. During our observation period, the sub-solar latitude of this asteroid was approximately $55^{\circ}S$, corresponding to the southern hemisphere of the body. Thus, we found that the southern hemisphere of Phaethon has a homogeneous surface from our observation results. In addition, we compared our spectra with archival data to investigate the latitudinal surface properties of the asteroid. The result showed that it doesn't have a latitudinal color variation. To verify this assumption, we investigated its solar-radiation heating effect, and the result suggested that this asteroid underwent a uniform thermal metamorphism regardless of latitude, which is consistent with our observations. Based on this result, we discuss the homogeneity of the surface of the body.

• 대기
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• 제34권1호
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• pp.69-81
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• 2024

In this paper, Annual flux variations in the Boseong Tall Tower (BTT) from 2016 to 2020 were analyzed using data from three levels (2.5 m, 60 m, and 300 m). BTT was installed in Boseong-gun, Jeollanam-do in February 2014 and continued to conduct energy exchange observations such as CO2, sensible heat, and latent heat using the eddy covariance method until March 2023. The BTT was located in a very flat and uniform paddy field, and flux observations were conducted at four levels: 2.5 m, 60 m, 140 m, and 300 m above ground. Surface energy balance was confirmed from observed data of net radiation flux, soil heat flux, sensible heat flux, and latent heat flux. Additionally, 2.5 m height surface fluxes, which are most influenced by agricultural land, were compared with data from Local Data Assimilation and Prediction System (LDAPS) of the Korea Meteorological Administration to evaluate the accuracy of LDAPS flux data. The correlation coefficient between LDAPS flux data and observed values was 0.95 or higher. Excluding summer latent heat flux data, there was a general tendency for LDAPS data to be higher than observed values. The footprint areas estimated below 60 m height mainly covered agricultural land, and flux observations at 2.5 m and 60 m heights showed typical agricultural characteristics. In contrast, the footprint estimated at 300 m height did not show agricultural characteristics, indicating that observations at this height encompassed a wide range, including mountains, sea, and roads. The analysis results of long-term flux observations can contribute to understanding the energy and carbon dioxide fluxes in agricultural fields. Furthermore, these results can be utilized as essential data for validating and improving numerical models related to such fluxes.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2014년도 자성 및 자성재료 국제학술대회
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• pp.85-85
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• 2014