• Title/Summary/Keyword: narrow region

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A Study on the Flow Structures in the Narrow Region (난접근 영역에서의 유동구조)

  • Ih, Kang-Duck
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.570-575
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    • 2008
  • Flows are studied to understand the flow structure in the narrow region that any experimental approaches are hard to access, Effects on the vehicle commodities from the flows are anticipated in the point of aerodynamics and aero-acoustics. PowerFLOW, which was well validated commercial software, was used to simulate the flow field in the small region, for example, the inner region of the fender panel, the inner region around the front door and the inner region of the trunk lid. Flows in the narrow region could be origins of door sealing problem and dust piling problem.

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The Study on the Scythian Costume III -Focaused on the Scythian of the Pazyryk region in Altai- (스키타이 복식 연구 III - 알타이 파지리크 지역 스키타이인을 중심으로 -)

  • Yi-Chang, Youngsoo
    • Fashion & Textile Research Journal
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    • v.18 no.4
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    • pp.424-437
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    • 2016
  • The study will analyze the costumes of the Scythians tribes who lived in the region of Altai in the 3-5 century BC. The purpose of this study is to prepare new material to re-examine the theory, which claims that the origin of the circular motives of korean costumes are to be found in the typology of the Scythian costumes. In this study, we analyzed the most recent reports of archaeological excavation about the unearthed clothes in the Pazyryk region and compared its information with european literature. The conclusion of this study is as follows: The jackets of the Pazyryk region are classified in two types, (1) opened jacket with narrow sleeve and (2) enclosed jacket with narrow sleeve. Trousers were separated by (1) narrow and (2) extreme wide trousers. The enclosed jacket of tunic form and extreme wide trousers are newly excavated. It proves, there was a vivid exchange between the Scythians and their neighboring cultures. It can be noted, that there existed a diverse Scythian culture of costumes, besides the commonly known clothing culture of the "Pazyryk-rider". Based upon the results of the previous research, it can be said that the opened jacket with narrow sleeve and narrow trousers are costume typologies which are common for all Scythian tribes of the whole Eurasian region. The hem of the edge of jacket is proven to be a connective element, which is common to all Scythian tribes.

Saturated Boiling Heat Transfer of Freon-113 in Hemispherical Narrow Space and Implications for Degraded Core Coolability in Reactor Vessel Lower Plenum

  • Bang, Kwang-Hyun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05a
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    • pp.574-579
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    • 1995
  • Saturated boiling heat transfer experiment in a hemispherical narrow space is conducted using Freon-113 to investigate an additional heat removal capability through a hypothetical gap between lower head and degraded core. The narrow space of 1mm consists of a 124mm diameter heated stainless steel hemisphere and a glass outer vessel. Within the hemispherical narrow space large coalesced bubbles are produced and these bubbles rise in random direction, causing liquid flow in from the opposite side to fill the region. Such flow in random direction makes the flow field in the narrow space very chaotic and thus enhance heat transfer. The heat transfer coefficient is higher at lower angle and at higher heat flux. The present study shows that the liquid from upper region can effectively penetrate into the gap and augment the heat removal capability through tile gap.

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The geophysical survey in shallow water and transitional region

  • Ashida Yuzuru
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.1-15
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    • 2002
  • In the present paper, the marine reflection seismic survey, the survey using Chirp sonar, the detail topographic survey by narrow multi-beam sounding machine, the sea bottom geological condition survey by side-scan sonar, the sea bottom sampling by core sampler and the positioning by DGPS as the geophysical survey in shallow and transitional region are introduced by placing emphasis on hardware configuration.

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EXPERIMENTAL INVESTIGATION OF CONVECTIVE HEAT TRANSFER IN A NARROW RECTANGULAR CHANNEL FOR UPWARD AND DOWNWARD FLOWS

  • Jo, Daeseong;Al-Yahia, Omar S.;Altamimi, Raga'i M.;Park, Jonghark;Chae, Heetaek
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.195-206
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    • 2014
  • Heat transfer characteristics in a narrow rectangular channel are experimentally investigated for upward and downward flows. The experimental data obtained are compared with existing data and predictions by many correlations. Based on the observations, there are differences from others: (1) there are no different heat transfer characteristics between upward and downward flows, (2) most of the existing correlations under-estimate heat transfer characteristics, and (3) existing correlations do not predict the high heat transfer in the entrance region for a wide range of Re. In addition, there are a few heat transfer correlations applicable to narrow rectangular channels. Therefore, a new set of correlations is proposed with and without consideration of the entrance region. Without consideration of the entrance region, heat transfer characteristics are expressed as a function of Re and Pr for turbulent flows, and as a function of Gz for laminar flows. The correlation proposed for turbulent and laminar flows has errors of ${\pm}18.25$ and ${\pm}13.62%$, respectively. With consideration of the entrance region, the heat transfer characteristics are expressed as a function of Re, Pr, and $z^*$ for both laminar and turbulent flows. The correlation for turbulent and laminar flows has errors of ${\pm}19.5$ and ${\pm}22.0%$, respectively.

CO OBSERVATIONS OF A HIGH LATITUDE HII REGION S73 WITH HIGH RESOLUTION AUTOCORRELATOR

  • LEE YOUNGUNG;CHUNG H.S.;KIM H.R.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.187-188
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    • 1996
  • We have mapped $1 deg^2$ region toward a high latitude HII region S73 (l, b) = ($37^{\circ}.69$, $44^{\circ}.55$) and associated molecular cloud in $^{12}CO$ J = 1 - 0, and $^{13}CO$ J = 1 - 0, using the 3 mm SIS receiver on the 14 m telescope at Taeduk Radio Astronomy Observatory. A high resolution autocorrelator is used to resolve extremely narrow CO linewidths (FWHP < 1 km/s) of the molecular cloud. Though the linewidths are very narrow, it is found that there is systematic velocity gradient in the molecular gas associated with the H II region. Both of $^{12}CO$ and $^{13}CO$ averaged spectra are non-gaussian, and there are obvious blue wings in the spectra. It is remarkable that the linewidths at the blueshifted region are broader than those of the rest of the cloud. The CO emission does match well with the dust emission.

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Three-Dimensional Analysis of the Coupled Turbulent Flow and Solidification During a Continuous Casting Process with Electromagnetic Brake (전자기 브레이크를 적용한 연속주조공정에서의 난류유동 및 응고의 3차원 해석)

  • Kim, Deok-Soo;Kim, Woo-Seung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.10
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    • pp.1254-1264
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    • 1999
  • A three-dimensional coupled turbulent fluid flow and solidification process were analyzed in a continuous casting process of a steel slab with Electromagnetic Brake(EMBR). A revised low-Reynolds number $k-{\varepsilon}$ turbulence model was used to consider the turbulent effects. The enthalpy-porosity relation was employed to suppress the velocity within a mushy region. The electromagnetic field was described by Maxwell equations. Tile application of EMBR to the mold region results in the decrease of the transfer of superheat to the narrow face, the increase of temperature in free surface region and most liquid of submold region, and the higher temperature gradient near the solidifying shell. The increasing magnetic flux density effects mainly to the surface temperature of the solidifying shell of narrow face, hardly to the one of wide face. It is seen that in the presence of EMBR a thicker solidifying shell is obtained at the narrow face of the slab.

Narrow-diameter implants with conical connection for restoring the posterior edentulous region

  • Woo, In-Hee;Kim, Ju-Won;Kang, So-Young;Kim, Young-Hee;Yang, Byoung-Eun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.38
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    • pp.31.1-31.7
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    • 2016
  • Background: The objective of this retrospective study was to show results from platform-switched narrow-diameter implants in the posterior edentulous region, which we followed up for more than 1 year after functional loading. Methods: Ninety-eight narrow implants were inserted into 66 patients. After healing, fixed implant-supported prostheses were delivered to the patients, and Periotest and radiographic examinations were performed. After the first year of loading, the implant outcome was again evaluated clinically and radiographically using the Periotest analysis. Crestal bone loss and Periotest values (PTVs) were used to evaluate the effect of surgery, prosthesis, implant, and a host-related factor. A general linear model was used to statistically detect variables statistically associated with crestal bone loss and Periotest value. Results: We followed up on the implants over 1 to 4 years after loading; their survival rate was 100 %, and pronounced differences from PTVs were noted among jaw location, bone quality, and loading period. No difference was detected in bone loss among the variables studied. Bone loss after functional loading was $0.14{\pm}0.39mm$. The stability value from the Periotest was $-3.29{\pm}0.50$. Conclusions: Within the limitations of this study, judicious use of platform-switched narrow implants with a conical connection must be considered an alternative for wide-diameter implants to restore a posterior edentulous region.

Narrow-line region of two radio-quiet quasars

  • Oh, Se-MYeong;Woo, Jong-Hak;Bennert, Vardha
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.53.1-53.1
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    • 2011
  • We investigate the radial properties of the narrow-line region (NLR) in two radio-quiet quasars, PG1012+008 and PG1307+085, using the spectra obtained with the FORS1 at the Very Large Telescope. These high quality spectra with seeing < 0.6" enable us to extract seven two-pixel (0.4") spectra as a function of the radial distance from the accretion disk. In contrast to [OIII] narrow-band imaging, which can be contaminated by starbursts, shock-ionized gas, and tidal tails, we use emission-line diagnostic to determine the true size of the AGN-excited NLR. In this poster, we present the results based on the radial variance of $H{\beta}$ to [OIII] ${\lambda}5007$ ratio. For both targets, the [OIII] emission line exhibits a blue wing, suggesting an outflow of gas. In the case of PG1307+085, the blue wing disappears at the distance of 1". We will discuss the properties of the NLR in detail.

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Modification of conventional X-ray diffractometer for the measurement of phase distribution in a narrow region

  • Park, Yang-Soon;Han, Sun-Ho;Kim, Jong-Goo;Jee, Kwang-Yong;Kim, Won-Ho
    • Analytical Science and Technology
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    • v.19 no.5
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    • pp.407-414
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    • 2006
  • An X-ray diffractometer for spatially resolved X-ray diffraction measurements was developed to identify phase in the narrow (micron-scaled) region of high burn-up fuels and some nuclear materials. The micro-XRD was composed of an X-ray microbeam alignment system and a sample micro translation system instead of a normal slit and a fixed sample stage in a commercial XRD. The X-ray microbeam alignment system was fabricated with a microbeam concentrator having two Ni deposited mirrors, a vertical positioner, and a tilt table for the generation of a concentrated microbeam. The sample micro translation system was made with a sample holder and a horizontal translator, allowing movement of a specimen at $5{\mu}m$ steps. The angular intensity profile of the microbeam generated through a concentrator was symmetric and not distorted. The size of the microbeam was $4,000{\times}20{\mu}m$ and the spatial resolution of the beam was $47{\mu}m$ at the sample position. When the diffraction peaks were measured for a $UO_2$ pellet specimen by this system, the reproducibility ($2{\Theta}={\pm}0.01^{\circ}$) of the peaks was as good as a conventional X-ray diffractometer. For the cross section of oxidized titanium metal, not only $TiO_2$ in an outer layer but also TiO near an oxide-metal interface was observed.