• 한국분말재료학회지
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• 제18권5호
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• pp.449-455
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• 2011

In this study, p-type $(AgSbTe_2)_{15}(GeTe)_{85}$: TAGS-85 compound powders were prepared by gas atomization process, and then their microstructures and mechanical properties were investigated. The fabricated powders were of spherical shape, had clean surface, and illustrated fine microstructure and homogeneous $AgSbTe_2$ + GeTe solid solution. Powder X-ray diffraction results revealed that the crystal structure of the TAGS-85 sample was single rhombohedral GeTe phase, which with a space group $R_{3m}$. The grain size of the powder particles increased while the micro Vickers hardness decreased with increasing annealing temperature within the range of 573 K and 723 K due to grain growth and loss of Te. In addition, the crystal structure of the powder went through a phase transformation from rhombohedral ($R_{3m}$) at low-temperature to cubic ($F_{m-3m}$) at high-temperature with increasing annealing temperature. The micro Vickers hardness of the as-atomized powder was around 165 Hv, while it decreased gradually to 130 Hv after annealing at 673K, which is still higher than most other fabrication processes.

• 천문학회지
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• 제56권1호
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• pp.97-115
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• 2023

We present the deep homogeneous UBV RI photometric data of 135,071 stars down to V ~ 23 mag and I ~ 22 mag toward the Carina Nebula. These stars are cross-matched with those from the previous surveys in the X-ray, near-infrared, and mid-infrared wavelengths as well as the Gaia Early Data Release 3 (EDR3). This master catalog allows us to select reliable members and determine the fundamental parameters distance, size, stellar density of stellar clusters in this star-forming region. We revisit the reddening toward the nebula using the optical and the near-infrared colors of early-type stars. The foreground reddening [E(B-V)_fg] is determined to be 0.35 ± 0.02, and it seems to follow the standard reddening law. On the other hand, the total-to-selective extinction ratio of the intracluster medium (R_V,cl) decreases from the central region (Trumpler 14 and 16, R_V,cl ~ 4.5) to the northern region (Trumpler 15, R_V,cl ~ 3.4). It implies that the central region is more dusty than the northern region. We find that the distance modulus of the Carina Nebula to be 11.9 ± 0.3 mag (d = 2.4 ± 0.35 kpc) using a zero-age main-sequence fitting method, which is in good agreement with that derived from the Gaia EDR3 parallaxes. We also present the catalog of 3,331 pre-main-sequence (PMS) members and 14,974 PMS candidates down to V ~ 22 mag based on spectrophotometric properties of young stars at infrared, optical, and X-ray wavelengths. From the spatial distribution of PMS members and PMS candidates, we confirm that the member selection is very reliable down to faint stars. Our data will have a legacy value for follow-up studies with different scientific purposes.

• Tuberculosis and Respiratory Diseases
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• 제52권4호
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• pp.411-418
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• 2002

저자 등은 폐결핵재발 후에 진행성의 호흡곤란과 만성기침을 호소하며 입원하여 흉부전산화 단층촬영 상에 폐포단백증의 특징적인 소견을 보이는 환자를 개흉 폐생검으로 확진하여 항결핵제 투여와 기관지폐포세척술로 임상적 호전을 보인 1예를 문헌고찰과 함께 보고하는 바이다.

• 조명전기설비학회논문지
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• 제19권2호
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• pp.13-22
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• 2005

채광과 직사광 제어라는 자연조명의 상반된 목적을 동시에 충족시키기 위하여 본 연구에서 기존의 유리 창호를 용도와 기능에 따라 채광창과 조망창의 두 부분으로 분리한 이중분할창호시스템이 설계되었다. 채광량을 극대화하기 위하여 고창부의 채광창은 투명유리를 사용하며 조망창은 제어를 위한 다양한 기능성 유리를 적용하였다. 부가적으로 물리적 광제어 및 조절장치인 광선반, 수평 및 수직형 블라인드가 내장된 일체형 이중분할창호를 포함한 포괄적인 광제어 기법의 양적$\cdot$질적 조명효과를 통합적으로 평가하여, 제안된 창호시스템의 적용성을 평가하였다. 조망창과 채광고창의 경계부에 수평형 광선반을 설치하면 일차적인 직사광 유입으로 인하여 극심하게 높은 조도를 나타내는 창면 관접부의 조도를 완화시키는 차폐효과와 아울러 광선반의 반사 능력으로 인하여 채광성능면에서 불리한 실내측 후면부의 조도를 증가시키는데 현격한 효과를 2차적으로 기대할 수 있다. 실내바닥 수평면의 평균조도는 차광기능에 의하여 균제도가 2배 이상 향상되며 수평 슬릿의 반사에 의하여 $16(\%)$ 이상 증가하는 효과가 있으며 태양고도가 낮고 방위각이 정남향이 아닌 경우 수직 차광재를 사용하면 광제어 기능으로 인한 균제도의 향상과 $10(\%)$이상의 후면부 조도의 증가 및 조망이 확보되는 상대적인 장점이 있다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2009년도 특별 심포지엄
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• pp.57-65
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• 2009

Selection of good mineralized area is a combination of the integration of all the available geo-scientific (i.e., geological, geochemical, and geophysical) information, extrapolation of likely features from known mineralized terrenes and the ability to be predictive. The time-space relationships of the hydrothermal deposits in the East Asia are closely related to the changing plate motions. Also, two distinctive hydrothermal systems during Mesozoic occurred in Korea: the Jurassic/Early Cretaceous deep-level ones during the Daebo orogeny and the Late Cretaceous/Tertiary shallow geothermal ones during the Bulguksa event. Both the Mesozoic geothermal system and the mineralization document a close spatial and temporal relationship with syn- to post-tectonic magmatism. The Jurassic mineral deposits were formed at the relatively high temperature and deep-crustal level from the mineralizing fluids characterized by the relatively homogeneous and similar ranges of ${\delta}^{18}O$ values, suggesting that ore-forming fluids were principally derived from spatially associated Jurassic granitoid and related pegmatite. Most of the Jurassic auriferous deposits (ca. 165-145 Ma) show fluid characteristics typical of an orogenic-type gold deposits, and were probably generated in a compressional to transpressional regime caused by an orthogonal to oblique convergence of the Izanagi Plate into the East Asian continental margin. On the other hand, Late Cretaceous ferroalloy, base-metal and precious-metal deposits in the Taebaeksan, Okcheon and Gyeongsang basins occurred as vein, replacement, breccia-pipe, porphyry-style and skarn deposits. Diverse mineralization styles represent a spatial and temporal distinction between the proximal environment of sub-volcanic activity and the distal to transitional condition derived from volcanic environments. However, Cu (-Au) or Fe-Mo-W deposits are proximal to a magmatic source, whereas polymetallic or precious-metal deposits are more distal to transitional. Strike-slip faults and caldera-related fractures together with sub-volcanic activity are associated with major faults reactivated by a northward (oblique) to northwestward (orthogonal) convergence, and have played an important role in the formation of the Cretaceous Au-Ag lode deposits (ca. 110-45 Ma) under a continental arc setting. The temporal and spatial distinctions between the two typical Mesozoic deposit styles in Korea reflect a different thermal episodes (i.e., late orogenic and post-orogenic) and ore-forming fluids related to different depths of emplacement of magma (i.e., plutonic and sub-volcanic) due to regional changes in tectonic settings.