• Title/Summary/Keyword: Central Column

Search Result 210, Processing Time 0.024 seconds

Water Column Structure and Dispersal Pattern of Suspended Particulate Matter (SPM) in a floating ice-dominated fjord, Marian Cove, Antarctica during Austral Summer (유빙이 점유한 남극 마리안 소만의 하계기간 수층 구조와 부유물질 분산)

  • Yoo, Kyu-Cheul;Yoon, Hoo-Il;Kang, Cheon-Yun;Kim, Boo-Keun;Oh, Jae-Kyung
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.5 no.4
    • /
    • pp.295-304
    • /
    • 2000
  • Vertical measurement of CTDT at about 30 min intervals and spatial surface temperature, salinity, and concentration of suspended particulate matters were conducted to elucidate the character of water column and the dispersal pattern in a floating ice-dominated fjord, Marian Cove, West Antarctica. Marian Cove showed two distinct water layers in terms of turbidity; 1) cold, fresh, and turbid surface plume in the upper 2 m,2) warm, saline, and relatively clean Maxwell Bay inflow between 15-45 m in water depth. Thermal melting of Maxwell Bay inflow and tidewater glacier/floating ices developed the surface mixed layer and the activity of floating ices cause Maxwell Bay inflow to be unstable. Due to the unstable water column, the development of Maxwell Bay inflow and subsequent surface plume are not influenced by tidal frequency. Coastal current generated by strong northwesterly wind may extend warm, saline, and turbid surface plume into the central part of the cove along the northern coast via the western coast of Weaver Peninsula. Terrigenous sediments of meltwaters from the glaciated ice cliffs near the corner of tidewater glacier and some coasts enter into the cove and their dispersion depends upon the hydrographic regimes (tide, wind, wave etc.). At the period of spring tide, the strong wind stress with the northwesterly wind direction reserve suspended sediment-fed surface plume and so allow the possibility of deposition of terrigenous sediments within the basin of cove.

  • PDF

Effect of Spinal Cord Removal before or after Splitting and Washing on CNST Decontamination of Beef Carcasses

  • Lim, D.G.;Kim, D.H.;Lee, M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.11
    • /
    • pp.1770-1776
    • /
    • 2007
  • Beef carcasses were examined to explore the effects of spinal cord removal and washing on central nervous system tissue (CNST) decontamination of the surface during the slaughtering process. A total of 15 carcasses were split by sawing centrally down the vertebral column and left sides of split carcasses were used for analysis. Samples were collected by swabbing the surface from 4 defined parts on the interior and 4 on the exterior of carcasses from the abattoir and analyzed using an ELISA-based test. The results showed that automatic and manual spray washing decreased CNST contamination, especially on the interior ventral parts of carcass surfaces (p<0.01), but did not decrease CNST on the interior dorsal parts. Increasing washing time to 60 s did not affect the reduction of CNST contamination. Samples following spinal cord removal prior to splitting showed lower calculated levels of "risk material" than the stated limit of detection (0.1%) of the ELISA kit on interior and exterior carcass parts (p<0.01). Therefore, spinal cord removal prior to splitting could be a very effective way to minimize CNST contamination of beef carcasses.

Simulated Moving Bed(SMB) Chromatography Simulation for Loxoprofen Racemates Separation (록소프로펜 라세미체 분리를 위한 유사이동층 크로마토그래피의 전산모사)

  • Kim, In Ho;Song, Sung Moon
    • Korean Chemical Engineering Research
    • /
    • v.49 no.5
    • /
    • pp.623-627
    • /
    • 2011
  • Simulated moving bed(SMB) chromatography was simulated for separating loxoprofen racemates. Aspen chromatography simulator was utilized with Henry's constants of loxoprofen racemates which were obtained by batch chromatography experiments. Raffinate stream concentrations as well as purities were calculated with various $m_2$ and $m_3$ values in the triangle diagram obtained from two Henry's constants 7.9 and 10.1. Purity values are high under the conditions that the $m_2-m^3$ coordinates are near the left central region in the diagram and feed flow rates are lower. Concentration profiles of raffinate and extract streams along SMB columns explain the purity change in the case of increasing the column numbers installed at SMB.

Testing the Geometry of AGN Tori through the Fraction of Optically-Selected Type 1 AGNs

  • Khim, Honggeun;Yi, Sukyoung K.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.2
    • /
    • pp.37.2-38
    • /
    • 2015
  • According to the unified model of AGNs, type 1 and 2 AGNs are intrinsically the same objects but seem different due to an obscuring matter which can block lights from the central engine of the AGN depending on the viewing angle. The obscuring object is thought to be shaped in a toroidal form and thus the geometry of tori of AGNs is an important factor to determine the fraction of type 1 (or type 2) AGNs. Oh et al. (2015) provides a new catalog of type 1 AGNs from SDSS DR7 in the nearby universe (z < 0.2) and it contains nearly 50% more type 1 AGNs than previously known. Using this new catalog, we test the fraction of type 1 AGNs along the black hole mass (MBH) and the bolometric luminosity of AGNs (Lbol), which are regarded as key parameters of the AGNs. First of all, because the methods to derive the black hole mass and the bolometric luminosity bear uncertainties, we test how the different methods lead to different values of type 1 fraction. We found that the fraction of type 1 AGNs varies with both MBH and Lbol. The extensively-studied, "receding torus model" can only explain the trend along Lbol and hence fails to explain the trend. To understand the new trend, we test the geometry of the torus based on the "clumpy torus model". We present our results on the basic properties of the torus such as a column density or opening angle and compare with those from previous studies based on other wavelengths (e.g. Infrared or X-ray).

  • PDF

NEAR-INFRARED SPECTROSCOPY OF CO RO-VIBRATIONAL ABSORPTION TOWARD HEAVILY OBSCURED AGNs

  • Shirahata, Mai;Nakagawa, Takao;Oyabu, Shinki;Usuda, Tomonori
    • Publications of The Korean Astronomical Society
    • /
    • v.32 no.1
    • /
    • pp.169-173
    • /
    • 2017
  • We provide a new physical insight on the hot molecular clouds near the nucleus of the obscured AGNs. We performed near-infrared spectroscopic observations of heavily obscured AGNs in order to reveal physical characteristics of molecular clouds, especially focused on the CO fundamental ro-vibrational absorption around $4.7{\mu}m$. We have made systematic moderate-resolution spectroscopic observations toward 30 representative (U)LIRGs using the AKARI/IRC, and some of the ULIRGs showed the strong CO absorption feature. For three bright (U)LIRGs that show a steep red continuum with the deep CO absorption feature, IRAS 08572+3915, UGC 05101, and IRAS 01250+2832, we have also made high-resolution spectroscopic observations using the Subaru/IRCS. We have successfully detected many absorption lines up to highly excited rotational levels, and these lines are very deep and extremely broad. The derived physical conditions of molecular clouds are extreme; the gas temperature is as high as several 100 to a 1000 K, the $H_2$ column density is larger than $10^{22}cm^{-2}$, and the gas density is greater than $10^7cm^{-3}$. Such hot and dense molecular clouds must exist around the central engine of the AGN.

A study on the transition of the type of openings constructed at backside of DAECHUNG in Korean traditional architectures (전통건축 대청 배면 개구부형식의 변천에 관한 연구)

  • 정명섭
    • Journal of the Korean housing association
    • /
    • v.5 no.2
    • /
    • pp.29-40
    • /
    • 1994
  • The purpose of this study is to survey the transition of the type of openings in korean traditional archiectures. To do this, various types of openings at the backside of Daechung of 23 Hyang-Gyo Myung-Ryun-Dangs were investigated. After the classification in some groups according to their types and their periods of constuction, the tasnsition of the type of openings was analysed. Results are as follows. (1) The openings constructed form 16th to 17th century, the earliest form, is a ledged and battened panel window(or framed and ledged panel window) whose mullion is built on the frame of window. It is presumed that these types were widely used before 17th century. (2) The next type is ledged and battened panel window(door) (or framed and ledged panel window) which lacks a mullion. These types were thought to be customed after 18th century. (3) The lastest type, which is appeared from 19th to 20th century, is an characteristic backside opening(ledged and battened panel window or framed and ledged panel window) that among 3 column spacings the central one is enlarged in comparison with the right and left ones. Through this transition pattern of the openings, can be menifested that the trend of 20th century is to enlarge convenience of usage by constuctiong door and eliminating some windows.

  • PDF

Isolation, structure elucidation and physicochemical properties of novel antibiotic polypeptide, $\varepsilon-(L-\beta-Iysine)$ polypeptide from Streptomyces sp. DWGS2

  • Donghyuk Shin;Kim, Daesung;Lee, Deoggeun;Lee, Hyeongkyu;Hoshik Won
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.6 no.1
    • /
    • pp.69-77
    • /
    • 2002
  • During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

  • PDF

Enantiomeric Separation of Methamphetamine Abused in Korea (우리나라에서 남용되는 메스암페타민의 거울상 이성질체분리)

  • Yoo, Young-Chan;Chung, Hee-Sun;Choi, Hwa-Kyung;Kim, Eun-Mi;Kim, Mi-Kyung;Kim, Sun-Choon
    • YAKHAK HOEJI
    • /
    • v.41 no.3
    • /
    • pp.277-282
    • /
    • 1997
  • Methamphetamine, which is the most commonly abused drug in Korea, exists in terms of d-, l- isomers and a racemate(dl). d-Methamphetamine is a potent central nervous system stimulant, whereas l-Methamphetamine is sold freely as a nasal decongestant. In addition, methamphetamine appears in different ratios of optical isomers by the clandestine synthesis applied. In this study, enetiomeric separation of methamphetamines was estabilished to distinguish the chirality of methamphetamines trafficked and abused in Korea. A gas chromatograph/mass spectrometer(GC/MS) system equipped with an achiral capillary column is used to isolate the isomers of methamphetamine after (S)-N-(trifluoroacetyl)-l-prolyl(TFP) deravatization.After analyzing 10 illicit methamphetamine powders and 10 positive urine samples, following findings were found: d-Methamphetamine was well resolved from l-Methamphetamine by chromatographic separation of TFP derivatibes on DB-5 with retention time of 11.80 and 11.35 min respectively. The detection of d-Methamphetamine in all 10 powders and 10 urine samples proves that all methamphetamines abused in Korea are illegally manyfactured and administred.

  • PDF

Bullet Train of Giant Nonlinear Internal Waves from Luzon Strait

  • Liu, Cho-Teng;Hsu, Ming-Kuang;Chen, Hsien-Wen;Wang, Dee-Way;Chyou, Yuan-Jie;Lee, Chang-Wei
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.934-937
    • /
    • 2006
  • In the northeastern South China Sea (SCS), fast westward moving (about 2.9 m/s) non-linear internal waves (NLIWs) are emanated nearly daily from the Luzon Strait. Their propagation speed is faster than NLIWs previously observed in the deep water of world oceans, their amplitude of 140 m or more is the largest free propagating NLIWs so far observed in the deep ocean. These NLIWs energized the top 1500 m of the water column, heaving it up and down in 20 min. Their associated energy density and energy flux are the largest observed to date. During 2005 and 2006 experiment, they were found west of the HengChun Ridge (HCR) that links Luzon and Taiwan Islands. This coincides with founding in satellite images, no NLIW front was found east of HCR. But, the turbulent environment east of HCR may prohibit surface signature of NLIWs that were emanated from sills between Batan Islands. The relative contribution of the two ridges on NLIW in Luzon Strait is still under study.

  • PDF

OBSERVATIONS OF THERMAL TRANSITIONS OF SiO TOWARD THE SGR A MOLECULAR CLOUD (Sgr A 분자운의 열적 SiO 천이선 관측연구)

  • MINH Y. C.;ROH D.-G.;KIM S. J.;OHISHI M.
    • Publications of The Korean Astronomical Society
    • /
    • v.16 no.1
    • /
    • pp.15-20
    • /
    • 2001
  • We observed the thermal transitions of SiO (J=I-0, 2-1) and $^{29}SiO$ (J=l-O) toward the Sgr A molecular clouds. The distribution and the velocity structure of SiO are very similar to previous results for 'quiet' interstellar molecules. We think· that the SiO has been well mixed with other molecules such as $H_2$ which may indicate that the formation of Sgr A molecular clouds was affected by the activities, such as shock waves or energetic photons, from the Galactic center in large scales. The total column density of SiO is about $4.1\times10^{14} cm^{-2}$ and the fractional abundance $SiO/H_2$ appears to be about 10 times larger than those of other clouds in the central region of our galaxy. The derived values are thought to be lower limits since the optical depths of the observed SiO lines are not very thin. The formation of SiO has been known to be critically related to shocks, and our results provide informative data on the environment of our Galactic center.

  • PDF