• Title/Summary/Keyword: ob/ob

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Measurements of Peroxyacetyl Nitrates at an Urban and a Rural Site in Korea (도시지역과 청정지역에서의 대기 중 PAN(PeroxyAcetyl Nitrate) 측정)

  • 김세웅;이강웅;김경렬
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.2
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    • pp.157-167
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    • 2001
  • Although PAN has ong been considered to belong to one of the most characteristic photooxidants, its concentra-tions have rarely been measured in a systematic manner in Korea. The first in-situ Measurements of PAN were made in concert with simultaneous analysis of NO, NO$_2$, $O_3$ and UV-Visible radiation intensity from Seoul and dong-Hae during Spring and early Summer of 1999. The aim of our study was to evaluate the behavior of photo-chemical species in a highly polluted urban air and a relative clean one. PAN were determined using a semi-auto-mated gas chromatograph equipped with an electron captured detection system. Calibration of the PAN was done by synthesizing liquid standards using a strong acid nitration of the corresponding peracid. The PAN concentra-tions were found in the range of a few ppbv in the urban air ad persistently less than a ppbv in the clean rural airs. Diurnal variations of PAN and $O_3$ were also observed consistently during the experiment with maxima occurring during the late daylight hours. While the positive dependency of $O_3$ production and PAN concentrations were ob-served in most occasion, the dependency became deviated significantly under changes in air masses.

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An analysis of ground supported farm silo with variable thickness (I) -Part I mechanical characteristics of shell with Variable thickness- (지반과 구조물사이의 상호작용을 고려한 변단면 도통형쉘의 해석 (I) -변단면 쉘의 역학적 특성 (I)-)

  • 조진구;조현영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.31 no.4
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    • pp.58-71
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    • 1989
  • This study aims to develop a computerized program for analysis of the ground-supported cylindrical shell structure with step varied section and to find out its mechanical characteri- stics through application of the developed program to the analysis of a ensiled farm silo as a model structure. The thickness of wall and bottom-plate of farm silo is assumed to be step-varied and its detailed structural dimensions are presented in Tab. 1 and 2. Several numerical case studies show that sectional stresses of the sample structures are largely reduced by adopting "varied section" design technique. And, other major results ob- tained from this study are summarize4 as follows ; 1. The variation of wall-thickness has a great influence on bending stresses of wall. Ho- wever, the larger the relative thickness of bottom-plate is, the smaller the influence is. 2. The magnitude of thickness of projecting toe of bottom-plate has negligible effect on sectional stresses 3. The conventional design methodology, which assumes the bottom edge of wall as clam- ped on ground, is proved to be discarded through the numerical analysis. 4. It is found that the "varied section" design technique should get similar effects as in the case of thick bott6m-plate having uniform thickness. 5. The variation of wall-thickness has a considerable effect on the bending stresses of bo- ttom-plate. Especially, this phenomenon is very remarkable in its projecting toe. In some cases. the negative bending moment may be acted on.

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Temperature Measurement Using Single-Mode Fiber Interferometric Sensor (단일모드 광섬유의 간섭계 센서를 이용한 온도측정)

  • 김덕수;이상호
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.2
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    • pp.1-5
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    • 1985
  • In this paper, temperature-induced optical phase shifts in single-mode fibers are studied both analytically and experimentally. Temperature sensor using single-mode fiber interferometer is designed and the temperature sensitivity of the sensor system is investigated. This fiber-optic temperature sensor which employs the Mach-Zehnder arrangement is a high sensitivity sensor of phase detection type. In this type, temperature changes are ob-served as a motion of an optical interference fringe pattern. In the measurements using interferometer, one of the important problems is to detect simultaneously the number and direction of fringe displacement resulting from physical perturbations (temperature, pressure, etc.). To realize this, the array detector using multi-mode fiber is designed. By this array detector the number and direction of fringe displacement is Ineasured very conveniently.

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Increased effects of Bee Venom on aromatase expression and activity in the human osteoblastic cells (인간 골아세포에서 aromatase 효소의 발현과 활성에 대한 봉독의 증강효과)

  • Choi, Woo-shik;Kim, Kap-sung
    • Journal of Acupuncture Research
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    • v.19 no.5
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    • pp.136-148
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    • 2002
  • 본 연구는 osteoblastic cells에서 estogen 의 생합성을 유도하는 aromatase의 activity에 대한 봉독(蜂毒)작용을 측정하여, 봉독치료시 Arthritis의 진행 억제 및 estogen의 의한 bone formation의 효과여부를 검증하기 위해 실행하였다. 사용된 세포주로는 Osteoblastic phenotype으로 분화가 유도되는 Human leukaemic cell line FLG 29.1 및 the primary first-passage osteoblastic cells (hOB cells)이며, 이들을 각각 배양하고 각각의 RNA를 isolation한 뒤 PCR 증폭을 하였다. Aromatase에 대한 활성인자인 TPA와 TGF-${\beta}1$ 및 봉독을 이용하여 aromatase의 expression 및 activity에 대해 미치는 영향을 측정한 바, aromatase expression은 FLG 29.1 cell와 hoB cells에서, 50nM TPA 24시간 처리, 봉독 2 ~ 4시간 처리와 TGF-${\beta}1$ 3시간 처리로 유도한 결과 TPA와 TGF-${\beta}1$의 경우는 서로 유사하였고, 봉독에서 상대적으로 높게 나타났다. Aromatase activity는 FLG 29.1 cell, hoB cells에서 24시간 incubation한 결과, 모든 실험에서 일정하게 선상증가를 보였다. $5{\mu}{\ell}/m{\ell}$ BV에서 TPA와 TGF-${\beta}1$보다 뚜렷하게 증가하였으며, 0.5mM Bt2-cAMP, 50nM dexametasone처리에서는 유의성이 없었다. Estrogen 생합성을 촉매하는 aromatase activity BV가 처리에서 현저하게 증가하였기에, Rheumatis arthritis의 bone destruction에 대해 BV가 효과적인 역할을 할 것으로 보여진다.

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A Study on the ballistic performance and fracture mode of anodized Aluminum 5052-H34 alloy laminates (알루미늄 5052-H34 합금 적층재의 방탄성능과 파괴모드에 관한 연구)

  • 손세원;김희재;박영의;홍성희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.507-512
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    • 2000
  • The ob.jective of this study is to determine fracture behaviors(penetrati0n modes) and resistance to penetration duringballistic impact of Al 5052-H34 alloy laminates and anodized Al 5052-H34 alloy laminates. Resistance to penetration is determined by $V_{50}$ ballistic limit, a statical velocity with 50% probability for complete penetration, test method. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed that result from V50 test and Projectile Through Plates (PTP) test at velocities greater than $V_{50}$. PTP tests were conducted with 0" obliquity at room temperature using 5.56mm ball projectile. $V_{50}$ tests with 0" obliquity at room temperature were conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Surface Hardness, resistance to penetration, and penetration modes of A1 5052-H34 alloy laminates compared to those of anodized Al 5052-H34 alloy laminates.y laminates.

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Maternal-Fetal Interaction Belief and Maternal-Fetal Interaction (모-태아상호작용 신념과 모-태아상호작용)

  • Kwon, Mi-Kyung
    • Child Health Nursing Research
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    • v.14 no.4
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    • pp.370-378
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    • 2008
  • Purposes: The purposes of this descriptive survey study were to describe levels of Maternal-Fetal Interaction Belief and Maternal-Fetal Interaction, and to define their correlation. Method: Data were collected from 273 pregnant women who visited one public health center and OB/GY clinic in Gangneung city. The instrument used for this study was a self-report questionnaire that included the Maternal-Fetal Interaction Belief scale(MFIBS) and maternal-fetal interaction. Results: The mean scores for maternal-fetal interaction belief and maternal-fetal interaction were $107.41{\pm}15.67$ and $31.75{\pm}5.92$ respectively. For maternal-fetal interaction belief, there were significant differences according to education, religion, income, feeding plan, marriage satisfaction, family support, and husband's love. For maternal-fetal interaction, there were significant differences according to mother's age, period of pregnancy, marriage satisfaction, family support, husband's love. There was a correlation between maternal-fetal interaction belief and maternal-fetal interaction. Conclusion: Maternal-fetal interaction belief is related to increase in maternal-fetal interaction and fetal development. It is essential to develop a maternal-fetal interaction program that includes maternal-fetal interaction belief.

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A High-Velocity Cloud Impact Forming a Supershell in the Milky Way

  • Park, Geumsook;Koo, Bon-Chul;Kang, Ji-hyun;Gibson, Steven J.;Peek, J.E.G.;Douglas, Kevin A.;Korpela, Eric J.;Heiles, Carl E.
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.39.1-39.1
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    • 2016
  • We report the discovery of a kiloparsec-size supershell in the outskirts of the Milky Way with the compact high-velocity cloud, HVC 040+01-282 (hereafter, CHVC040), at its geometrical center using the "Inner-Galaxy Arecibo L-band Feed Array" HI 21 cm survey data. Supershells are large gaseous shells, which could be produced by one of most energetic activities with an explosion energy more than $3{\times}1052erg$. The most promising origin is the explosion of multiple supernovae in OB associations, or alternatively, the impact of HVCs falling into the Galactic disk. We found the association between CHVC040 and the Galactic supershell by analysis of their morphological and physical properties. Our results imply that some compact HVCs can survive their trip through the Galactic halo and inject energy and momentum into the Milky Way disk.

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A Wireless Camera Image Transmission System (COFDM 전송기술을 이용한 Wireless 카메라영상 전송시스템 연구)

  • Kim, Joon-Won
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.89-96
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    • 2010
  • In this paper, "a wireless camera image transmission system" is aimed for the free camera shooting in the indoor and outdoor environments. Currently in broadcasting program production environments, because the cable connections between TV OB VAN(outside broadcasting VAN) and EFP camera or ENG camera have many obstacles and limits of distances, it is very unconvienent for the free camera shooting. Therefore in this paper, wireless image transmission device and receiving device in DVB-T broadcasting are developed. In this paper, analog composite image signal output camera, image signal compression MPEG-2 system and COFDM mage transmission system are produced and experimented. The results for the image and transmission system had good QoS values and from this results, it is possible to apply TV program productions and wireless CCTV device industries.

Study on the Performance Characteristics of Centrifugal Pump with Drag-reducing Surfactant Additives

  • Wang, Lu;Li, Feng-Chen;Dong, Yong;Cai, Wei-Hua;Su, Wen-Tao
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.2
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    • pp.223-228
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    • 2011
  • The performance characteristics of centrifugal pump were measured experimentally when running with tap water and drag-reducing surfactant (Octadecyl dimethyl amine oxide (OB-8)) solutions. Tests have been performed on five cases of surfactant solutions with different concentrations (0ppm (tap water), 200ppm, 500ppm, 900ppm and 1500ppm) and four different rotating speeds of pump (1500rpm, 2000rpm, 2500rpm and 2900rpm). Compared with tap water case, the experimental results show that the total pump heads for surfactant solution cases are higher. And the pump efficiency with surfactant solutions also increases, but the shaft power for surfactant solutions cases decreases compared to t hat for tap water. There exists an optimal temperature for surfactant solutions, which maximizes the pump efficiency.

Leptin: the link between adipose tissue and reproductive system

  • Chen, Ming-Dao
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.15-23
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    • 2003
  • Interest in the regulation of body weight and the pathological physiology of obesity has been rekindled by the cloning of the obese(ob) gene and identification of its product, leptin, in 1994. The first publication appeared in Nature and is a milestone of obesity research. The remarkable metabolic effects of leptin in rodents are: a) inhibition of food intake, b) stimulation of energy expenditure, and c) reversal of obesity. These effects, though mostly desirable, have not been fully demonstrated in humans. The central action of leptin in the regulation of body weight includes two pathways in rodents: a) When the body weight increasing, more leptin is secreted from adipose tissue, which acts on hypothalamus, probably through a POMC or MSH pathway via M4 receptor, initiates a series of response to obesity, i.e. sympathetic tone increased, energy expenditure enhanced and food intake reduced. b) When body weight reduced, leptin concentration decreased with the shrinkage of fat mass, which may also act on the hypothalamus, probably through a NPY-Y5 receptor pathway. Then a cascade of response to hungry was induced, i.e. increase of parasympathetic tone and food intake, decrease of energy expenditure and body temperature, as well as shut-down of the reproductive function.

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