• 제목/요약/키워드: Positive Column

검색결과 332건 처리시간 0.033초

열대 지역 Gross Moist Stability 특징 분석 및 미래 변화 (Characteristics of the Gross Moist Stability in the Tropics and Its Future Change)

  • 김혜원;서경환
    • 대기
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    • 제24권2호
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    • pp.141-150
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    • 2014
  • This study investigates the characteristics of the Gross Moist Stability (GMS) over the tropics. The GMS summarizes the relationship between large-scale entropy forcing due to radiation and surface fluxes and the response of smaller-scale convection. The GMS is able to explain both to where moist entropy is advected by the atmospheric circulation and how deep the moisture flux convergence is in the tropical region. In the deep convective region, positive GMS appears over the warm pool region due to the strong column-integrated moisture convergence and the ensuing export of moist entropy to the environment. The vertical advection of moist entropy dominates over the horizontal advection in this region. Meanwhile, over the eastern tropical ITCZ region, which is characterized by shallow convective area, import of moist entropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. A decrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to an increased region of precipitation, implying that strengthened convection in the future due to increased entropy forcing exports the enhanced moist energy to stabilize the environment.

길경(Platycodi Radix) Butanol 분획물의 항염증 활성 성분 (Anti-Inflammatory Components of Platycodi Radix Butanol Fractions)

  • 김성연;이은방;정은자
    • 동아시아식생활학회지
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    • 제22권6호
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    • pp.772-781
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    • 2012
  • This study was conducted to examine the development of a new anti-inflammatory substance with potent anti-inflammatory activities that was derived from the Platycodi Radix butanol fraction. To accomplish this, the chemical structures and anti-inflammatory activities of the components were elucidated. Upon column chromatography of the tertiary subfraction, fractions 8-4-1 and 8-4-2 were identified as platycodin D and D3, respectively, following recrystallization, based on melting point (MP), infrared (IR), and positive fast atom bombardment (FAB)-mass and nuclear magnetic resonance (NMR) spectral data. Platycodin D and D3 exhibited strong anti-inflammatory activities in rats when administerd at oral doses of 12 mg/kg and 36 mg/kg, p.o., respectively. Platycodin D and D3 induced inhibitory effects on capillary vascular permeability in rats at oral doses of 16 mg/kg and 24 mg/kg, p.o., respectively, and potent inhibition of leukocyte emigration in a carboxymethyl cellulose (CMC)-pouch when administered at doses of 3 mg/rat and 7 mg/rat, s.c., respectively. These results verified the high antiinflammatory potency of the platycodin D and D3 components in Platycodi Radix.

축산식품 중 비스테로이드성 항염증 약물의 잔류함량 모니터링 (Mornitoring of non-steroidal anti-inflammatory drugs in livestock products)

  • 최윤화;김연주;신방우;이정학
    • 한국동물위생학회지
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    • 제34권3호
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    • pp.285-289
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    • 2011
  • This study was conducted to determine the content of non-steroidal anti-inflammatory drugs (NSAIDs) in meats available on the Korean markets. The analysis was carried out using following conditions; C18 column ($100{\times}2.1$ mm, 1.7 ${\mu}m$), mobile phase composed of DW (containing 0.1% formic acid): acetonitrile (containing 0.1% formic acid), binary pump at a flow rate of 0.3 ml/min and 5 ${\mu}l$ of injection volume, MS/MS detector with ESI positive mode. The calibration range of five NSAIDs showed linearity ($r^2{\geq}0.99$) at concentration range of 3.125~200 ${\mu}g$/kg. The recoveries in fortified muscle more than 78.7~100.3%. The detection limits for meloxicam, ketoprofen, flunixin, carprofen and tolfenamic acid were 3.5, 1.6, 1.7, 9.8 and 4.8 ${\mu}g$/kg, respectively. We also monitored NSAIDs residue in cattle muscle 51 samples. The test results, NSAIDs were all not founded.

1,2,4-트리메틸벤젠에 피폭된 노동자의 뇨 중 3,4-디메틸히푸르 산과 크레아티닌의 정량 (Determination of 3,4-Dimethylhippuric Acid and Creatinine from the Urine of Workers Exposed to 1,2,4-Trimethylbenzene)

  • 임정미;장재연;이용문;강종성
    • 약학회지
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    • 제41권6호
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    • pp.692-697
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    • 1997
  • Creatine and 3,4-Dimethylhippuric acid (3,4-DMHA), a glycine conjugate of 1,2,4-trimethyl-benzene (1,2,4-TMB) were determined in the urine of workers exposed to 1,2,4-TMB vapor. The best condition for the simultaneous determination of 3,4-DMHA and creatine by high performance liquid chromatography was obtained by reverse phase $C_{18}$ column (4.6${\times}$150mm, 5${\mu}m$) as stationary phase and 20% acetonitrile in 20mM phosphate buffer (pH 3.0) containing 4mM sodium octylsulfate(SOS)as mobile phase. The recovery of 3,4-DMHA spiked to blank urine in the range of 1~5${\mu}g$/ml was about 96%. The concentration of urinary 3,4-DMHA of workers had a positive correlation with the environmental level of 1,2,4-TMB (r=0.866). The data suggest that urinary 3,4-DMHA concentration is a useful biological index for 1,2,4-TMB exposure.

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진주시 직장인의 외식 선택 요인 (Factors Influencing Salaried Employees' Choice of a Restaurant in JinJu)

  • 김석영
    • 한국식생활문화학회지
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    • 제19권1호
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    • pp.83-93
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    • 2004
  • A total of 321 salaried employees were surveyed by a questionnaire to assess consumers perceptions on factors influencing their food choices when they go to a restaurant. The questionnaire consisted of 5 pages and each page contained a same 26 popular food list from various restaurants in JinJu in a column and 5 attributes (e.g. taste, price, fullness, healthiness) in a row. So the respondents were asked to rate a total 25 attributes on the points which the columns and the rows met, using a 5-point scale. The data were analyzed using the SAS program for factor analysis. Five factors which influence consumer's restaurant choice were emerged. They were named as follow: Factor 1:preference and purpose, Factor 2:taste, Factor 3:snack, Factor 4:convenience, Factor 5:concern about obesity. Most of respondents were satisfied with the taste and the healthiness of foods of restaurants in Jin-Ju. The younger and the female groups had more positive attitudes on eating out andi willing to use it frequently. Fullnes, healthiness, and price were important criteria in choice and preference of a restaurant. However, they didn't much consider the food safety. Taking account of the character of Korean food about fullness, healthiness, and resonable price, consumers might prefer Korean food to fast food or foreign food.

기체 방전관의색상 제어에 관한 연구 (A Study on Color Control in Gas Discharge Tube)

  • 이종찬;청야정명;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.285-288
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    • 1996
  • The electronic operation of the gas discharge tube is controlled by the electrical energy as sinusoidal waveform in arbitrary frequency range, or as a sequence of pulses at a wide range of duty cycle, the gas composition, the kind of electrode and the vessel geometry. In this paper, the pulsed mode operated gas discharge tube is composed with mixed gas of IIg-Ne ( 10 Torr ), in the tube of 15.0 mm outer diameter and has variable color from red to blue with changing frequency and pulse width in high voltage. As increasing pulse width and frequency in the gas discharge tube, the phenomenons that the electron temperature in the positive column increases and the radiation from atoms of higher upper state energy levels increases, exist. The color have the locus from red (0.4972, 0.3128) to blue (0.2736, 0.2619) in CIE chromacity diagram with increasing pulse width and frequency. The changing method of pulse width and frequency has been shown to be suitable for the luminous color control.

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Streptomyces속 균주가 생성하는 $\alpha$-D-Glucosidase 저해물질의 물리학적 성질 (Physico-Chemical Characteristics of $\alpha$-D-Glucosidase Inhibitor from Streptomyces sp)

  • 도재호;주현규
    • 한국미생물·생명공학회지
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    • 제18권1호
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    • pp.35-38
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    • 1990
  • 정제된 저해물질의 Rf치는 0.12-0.71 사이였으며 melting point는 154.3-155.3$^{\circ}C$로 나타났다. 물, formic acid, ethylene glycol monomethyl ether에는 용해되지만 그외 대부분의 용매에서는 불용성이었고 흡습성이 매우 큰 물질이었다. Phenol-sulfuric acid, ninhydrin, silvernitrate-sodium hydroxide 반응은 양성이었으나, DNS 반응에서는 음성이며 자외선 조사하에서 형광을 나타내었다. 저해물질의 구성성분은 fructose와 aspartic acid로 확인되었으며 분자량이 약 1,050 정도였다.

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A Study of the Retention Behavior of Proteins in High-Performance Liquid Chromatography(II): The Effect of Salt and Temperature on Retention Behavior of Proteins in Hydrophobic Interaction Chromatography

  • Dai Woon Lee;Byung Yun Cho
    • Bulletin of the Korean Chemical Society
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    • 제14권4호
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    • pp.515-519
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    • 1993
  • The retention behavior of proteins was investigated by using hydrophobic interaction chromatography (HIC), comparing to the results obtained in reversed-phase chromatography (RPC) described in the previous paper. A SynChropak propyl column was employed with 0.05 M phosphate buffer (pH 7.0) containing sodium sulfate. Conformational changes were recognized by examining Z values as a function of sodium sulfate concentration over a range of temperature between 5 and 65$^{\circ}C$. Z values did not change significantly at the range of the temperature showing the consistent ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ values. The sign and the magnitude of ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ of proteins in HIC were compared with those obtained in RPC. The signs of ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ of proteins in HIC were all positive, while those of proteins in RPC were all negative. These results suggested that the retention of proteins in HIC and in RPC were entropy-driven and enthalpy-driven process, respectively. From the two different investigations, it was concluded that the retention mechanism of RPC and HIC was based on the same fundamental principle in which separation is dependent on hydrophobicity, but the retention behavior of the proteins in HIC is clearly different from that observed in RPC.

Identification of IY81149 and Its Metabolites in the Rat Plasma Using the On-Line HPLC/ESI Mass Spectrometry

  • Myung, Seung-Woon;Min, Hye-Ki;Jin, Chang-Bae;Kim, Myung-Soo;Lee, Seung-Mok;Chung, Gi-Ju;Park, Seong-Jun;Kim, Dong-Yeon;Cho, Hyun-Woo
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.189-193
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    • 1999
  • Reversed-phase high-performance liquid chromatography/mass spectrometry (HPLC/MS) with an eletcrospray ionization (ESI) interface was applied to the identification of metabolites of IY81149 in the rat plasma. Fragments obtained using collision-induced dissociation (CID) in both positive and negative modes were utilized to elucidate the structure of metabolites. The eluent from the conventional HPLC column was split and directly introduced into an ESI-mass spectrometer for the identification of the structures. the CID technique allowed the sensitive identification of sulfonyl-IY81149 and hydroxy-IY81149 from the rat plasma.

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Self-Supported NiSe/Ni Foam: An Efficient 3D Electrode for High-Performance Supercapacitors

  • Zhang, Jingtong;Zhao, Fuzhen;Du, Kun;Zhou, Yan
    • Nano
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    • 제13권11호
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    • pp.1850136.1-1850136.12
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    • 2018
  • Three-dimensional (3D) mixed phases NiSe nanoparticles growing on the nickel foam were synthesized via a simple one-step hydrothermal method. A series of experiments were carried out to control the morphology by adjusting the amount of selenium in the synthetic reaction. Meanwhile, the as-prepared novel column-acicular structure NiSe exist three advantages including ideal electrical conductivity, high specific capacity and high cycling stability. It delivered a high capacitance of $10.8F\;cm^{-2}$ at a current density- of $5mA\;cm^{-2}$. An electrochemical capacitor device operating at 1.6 V was then constructed using NiSe/NF and activated carbon (AC) as positive and negative electrodes. Moreover, the device showed high energy density of $31W\;h\;kg^{-1}$ at a power density of $0.81kW\;kg^{-1}$, as well as good cycling stability (77% retention after 1500 cycles).