• Title/Summary/Keyword: counter current distribution

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The Impact of Workplace Democracy on Social Capital: The Moderating Effect of Servant Leadership (조직 내 민주성이 사회적 자본의 형성에 미치는 영향: 서번트 리더십의 조절효과)

  • LI, Yiran;SONG, Kwancheol
    • The Journal of Industrial Distribution & Business
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    • v.10 no.7
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    • pp.59-69
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    • 2019
  • Purpose - Unlike in the past, individualistic thought is more dominant than groupism where members prioritize organizations. Such changes run counter to the direction of the survival of the companies, which calls for companies to explore strategies to address thems. As one of the solutions, many people highlights social capital. However, since most studies have been conducted on the definition and characteristics of social capital, there is not enough prior factor research on the formation of social capital. So the current situation require researches on the formation of social capital. Research design, data, and methodology - To achieve the purpose, the literature and the empirical studies were combined. Deriving workplace democracy and servant leadership as factors affecting the formation of social capital through the literature, and this factors have modeled assumptions about the impact on social capital, and have established hypotheses to verify them. The survey which is conducted to verify the hypothesis and questionnaires are derived base on the variables used in the previous studies. The survey was conducted 447 respondents in Korea. Results - As a result, we found that the workplace democracy is positively functioning with the formation of social capital. It means that the democracy functions as a universal element to enhance the quality of social capital at the workplace. The evidence also shows that the positive impacts of the servant leadership on the formation of social capital. And the survey shows that groups with high level servant leadership had a higher impact on the formation of social capital than those with low levels leadership. Conclusions - At present, the social capital has become an important factor for the companies pursuing high performance workplaces. We found that the workplace democracy and the servant leadership affect the formation of social capital. It means that to increase the employees' sense of community and solidarity, it is need to form democratic environment with the servant leadership. Therefore, based on the results of this study, the workplace democracy and the servant leadership can present strategic implications that can increase the social capital.

Distribution and Inter-annual Variation of Nutrients (N, P, Si) and Organic Carbon (DOC, POC) in the Equatorial Thermocline Ridge, Northeast Pacific (북동태평양 적도 Thermocline Ridge 해역에서 영양염(질소, 인, 규소)과 유기탄소(용존 및 입자)의 분포 특성 및 연간 변화)

  • Son, Ju-Won;Kim, Kyeong-Hong;Kim, Mi-Jin;Son, Seung-Kyu;Chi, Sang-Bum
    • Ocean and Polar Research
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    • v.33 no.1
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    • pp.55-68
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    • 2011
  • The distribution and inter-annual variation of nutrients (N, P, Si) and dissolved/particulate organic carbon were investigated in the equatorial thermocline ridge ($7^{\circ}{\sim}11.5^{\circ}N$, $131.5^{\circ}W$) of the northeast Pacific. From the Oceanic Nino Index and Multivariate ENSO Index provided by NOAA, normal condition was observed in July 2003 and August 2005 on the aspect of global climate/ocean change. However, La Ni$\~{n}$a and El Ni$\~{n}$o episodes occurred in July 2007 and August 2009, respectively. Thermocline ridge in the study area was located at $9^{\circ}N$ in July 2003, $8^{\circ}N$ in August 2005, $10^{\circ}N$ in July 2007, and $10.5^{\circ}N$ in August 2009 under the influence of global climate/ocean change and surface current system (North Equatorial Counter Current and North Equatorial Current) of the northeast Pacific. Maximum depth integrated values (DIV) of nutrients in the upper layer (0~100 m depth range) were shown in July 2007 (mean 21.12 gN/$m^2$, 4.27 gP/$m^2$, 33.72 gSi/$m^2$) and higher variability of DIV in the equatorial thermocline ridge was observed at $10^{\circ}N$ during the study periods. Also, maximum concentration of dissolved organic carbon (DOC) in the upper 50 m depth layer was observed in July 2007 (mean $107.48{\pm}14.58\;{\mu}M$), and particulate organic carbon (POC, mean $9.42{\pm}3.02\;{\mu}M$) was similar to that of DOC. Nutrient concentration in the surface layer increased with effect of upwelling phenomenon in the equatorial thermocline ridge and La Ni$\~{n}$a episode, which had formed in the central Pacific. This process also resulted in the increasing of organic carbon concentration (DOC and POC) in the surface layer. From these results, it is suggested that spatial and temporal variation of chemical and biological factors were generated by physical processes in the equatorial thermocline ridge.

The Distribution of Planktonic Protists Along a Latitudinal Transect in the Northeast Pacific Ocean (북동 태평양수역에서 위도에 따른 부유 원생동물의 분포)

  • Yang, Eun-Jin;Choi, Joong-Ki;Kim, Woong-Seo
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.287-298
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    • 2004
  • As a part of Korea Deep Ocean Study program, we investigated the distribution of planktonic protists in the upper 200 m of the northeast Pacific from $5^{\circ}N$ to $17^{\circ}N$, along $131^{\circ}30'W$. Area of divergence was formed at $9^{\circ}N$ which is boundaries of the north equatorial counter current (NECC) and the north equatorial current (NEC) during this cruise. Chlorophyll-a concentration was higher in NECC than in NEC area. Pico chl-a(<$2\;{\mu}m$) to total chl-a accounted for average 89% in the study area. The contribution of pico chl-a to total chl-a was relatively high in NEC area than in NECC area. Biomass of planktonic protists, ranging from 635.3 to $1077.3\;mgC\;m^{-2}$(average $810\;mgC\;m^{-2}$), was most enhanced in NECC area and showed distinct latitudinal variation. Biomass of HNF ranged from 88.7 to $208.3\;mgC\;m^{-2}$ and comprised 15% of planktonic protists. Biomass of ciliates ranged from 123.6 to $393.0\;mgC\;m^{-2}$ and comprised 25% of planktonic protists. Biomass of HDF ranged from 407.2 to $607.8\;mgC\;m^{-2}$ and comprised 60% of planktonic protists. HDF was the most dominant component in both NECC and NEC areas. Nano-protist biomass accounted for more than 50% of total protists in the both areas. The contribution of nanoprotist to total protists biomass was relatively higher in NEC area than in NECC. The biomass of planktonic protists was significantly correlated with phytoplankton biomass in this study area. The size structure of phytoplankton biomass coincided with that of planktonic protists. This suggested that the structure of the planktonic protists community and the microbial food web were dependent on the size structure of the phytoplankton biomass. However, biomass and size structure of planktonic protist communities might be significantly influenced by physical characteristics of the water column and food concentration in this study area.

Study on the Separation of MAs from HLLW and Their Extraction Behavior Using New Extractants of Amido Podand

  • An, Ye-Guo;Luo, Fang-Xiang;Zhu, Zhi-Xuan;Zhang, Xiang-Ye;Zhu, Wen-Bin
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.02a
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    • pp.245-256
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    • 2004
  • The extraction of three kinds of amido podands, N,N,N'N'-tetrabutyl-3-oxa-pentanedi- amide (TBDGA), N,N,N'N'-tetra-isobutyl-3-oxa-pentanediamide(TiBDGA) and N,N,N'N'-tetra- butyl-3,6-dioxa-oct-anediam- ide(TBDOODA) on U(VI),Pu(IV), Am(III), Eu(III) and other metal ions is studied in nitric acid solutions. 40%octanol-kerosene is chosen as diluents to eliminate third phase and emulsion. TBDGA and TiBDGA show extraction selectivity to An(III) and Ln(III) much higher than to U(VI) and Pu(IV). Fe, Ru and Mo is poorly extracted by the three kinds of amid podands in 2~3mol/L $HNO_3$ solutions. Aiming to eliminate interface crude when using simulated HLLW solution in the system of 0.2mol/L TBDGA/Octanol+kerosene, acetohydroxyamic acid was adapted. Distribution ratio of zirconium was decreased when adding acetohydroxyamic acid in aqueous solution, and interface crude disappeared as mixing extractant with HLLW. The counter-current extraction test is carried out in a set of miniature mixer-settler, with 0.2mol/L TBDGA/ 40% octanol-kerosene as extractant to separate U(VI), Pu(IV), Am(III) and Eu(III) from simulated high level liquid waste(HLLW) solution. In battery A, lanthanides and actinides are coextracted into organic phase with the recovery of 99.98% for U(Ⅵ), >99.99% for Pu(IV), and >99.99% for Am(III) and Eu(III) respectively. In battery R1, 99.99% U, 86.2% Pu and a part of Am or Eu are stripped into aqueous phase by 0.2mol/L acetohydroxyamic acid (AHA) in 0.01mol/L $HNO_3$ solution. In battery $R_2$, Am, Eu and remained Pu are completely back-extracted by 0.2mol/L AHA. This separation process contains no salt reagent, and it is not necessary to dilute HLLW feed.

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Identification of natural insecticidal compound in medicinal plants against diamondback moth (약초(藥草) 중에 존재(存在)하는 배추좀나방에 대한 천연살충성(天然殺蟲性) 물질(物質)의 동정(同定))

  • Chun, Jae-Chul;Kim, Sung-Eun;Kim, Jin-Cheol;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.3 no.1
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    • pp.13-19
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    • 1999
  • Insecticidal potentials of polar and non-polar tractions obtained from 84 medicinal plants were screened against five major agricultural insects. Based on the primary and secondary screening results, non-polar fraction of Atractylodes koreana Kitam. rhizomes was selected to isolate and identify an active compound effective to diamondback moth (Plutella xylostella L.) larvae. Counter-current distribution separation on the non-polar fraction and TLC and spectroscopic analyses (GC-MS and $^{1}H$- and $^{13}C$-NMR) revealed that molecular formula of the active compound was $C_{15}H_{22}O$ known as a sesquiterpenoid 4,11-selinadien-3-one (${\alpha}$-cyperone). However, ${\alpha}$-cyperone was not detected in the non-polar fractions that showed high insecticidal potential against the diamondback moth. Although ${\alpha}$-cyperone has been first identified from Cyperus rotundus, the compound did not occur in C. rotundus cultivated in Korea.

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Experiment of Distributed Optical Fiber Sensor Using Spatially-Selective Brillouin Scattering (공간 선택적 브릴루앙 산란을 이용한 분포형 광섬유 센서의 실험)

  • Seo, Min-Sung;Yun, Seung-Chul;Hyun, Jin-Young;Park, Hee-Gap
    • Korean Journal of Optics and Photonics
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    • v.17 no.3
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    • pp.223-230
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    • 2006
  • We demonstrate a distributed fiber sensor system based on spatially-selective Brillouin scattering, using a single laser diode as a light source whose optical frequency is directly modulated by the injection current. The pump and the counter-propagating probe lights, which are sinusoidally frequency-modulated, are superposed in the fiber so that stimulated Brillouin scattering takes places only at a specific location along the fiber. Brillouin gain peak position is controlled by varying the modulation frequency. Distributions of Brillouin shift frequency are measured for the case of concatenated optical fibers of two different kinds and also for the case of temperature distribution. The temperature coefficient of the Brillouin shift frequency is measured to be $1.33MHz/^{\circ}C$.

Study on threat analysis about national important facility and control process (국가중요시설에 대한 위협분석과 처리절차에 관한 연구 - 인천국제공항을 중심으로 -)

  • Hwang, Ho-Won;Lee, Ki-Hun
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.17 no.2
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    • pp.31-40
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    • 2009
  • South Korea opened Incheon international airport(IIA) in march 29, 2001, with high expectations of becoming the distribution hub of Northeast Asia and aiming at a world best air hub. IIA compares quite well with any other leading airports in the world in it's facilities for the movement of people and vehicles. However, with the sequence of events following the September, 2001. terrorist attack and the war in Iraq, South Korea, an ally of the US, cannot be considered a safe haven from terrorism. At a point in time when national security is given utmost importance, it is necessary to reevaluate the security of airports, because international terrorism can only occur via air and seaports. Nowadays all the countries of the world have entered into competition for their national interests and innovation of their images. with the increasing role of international airports also comes an increased likelihood as a terrorist target, because it can affect so many people and countries. From the condition of current international terrorism, we can realize that our IIA is not completely safe from a terrorist attack. The major part of counterterrorism is event control process. It's very important for quickly saves an accident and rescues a life of person, In addition for the normalization which the airport operation is prompt. In conclusion, we should secure the legal responsibility and establish and establish a system under which we can work actively in order to implement counter terror activities from being taken an airport.

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Experimental study on air-water countercurrent flow limitation in a vertical tube based on measurement of film thickness behavior

  • Wan, Jie;Sun, Wan;Deng, Jian;Pan, Liang-ming;Ding, Shu-hua
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1821-1833
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    • 2021
  • The gas-liquid counter-current flow limitation (CCFL) is closely related to efficient and safety operation of many equipment in industrial cycle. Air-water countercurrent flow experiments were performed in a tube with diameter of 25 mm to understand the triggering mechanism of CCFL. A parallel electrode probe was utilized to measure film thickness whereby the time domain and frequency domain characteristics of liquid film was obtained. The amplitude of the interface wave is small at low liquid flow rate while it becomes large at high liquid flow rate after being disturbed by the airflow. The spectral characteristic curve shows a peak-shaped distribution. The crest exists between 0 and 10 Hz and the amplitude decreases with the frequency increase. The analysis of visual observation and characteristic of film thickness indicate that two flooding mechanisms were identified at low and high liquid flow rate, respectively. At low liquid flow rate, the interfacial waves upward propagation is responsible for the formation of CCFL onset. While flooding at high liquid flow rate takes place as a direct consequence of the liquid bridging in tube due to the turbulent flow pattern. Moreover, it is believed that there is a transition region between the low and high liquid flow rate.

Measurement and analysis of PM10 and PM2.5 from chimneys of coal-fired power plants using a light scattering method (광산란법을 이용한 국내 석탄화력발전소 굴뚝에서 배출되는 PM10, PM2.5 측정 및 분석)

  • Shin, Dongho;Kim, Younghun;Hong, Kee-Jung;Lee, Gunhee;Park, Inyong;Kim, Hak-Joon;Kim, Yong-Jin;Han, Bangwoo;Hwang, Jungho
    • Particle and aerosol research
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    • v.16 no.4
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    • pp.131-140
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    • 2020
  • Air pollutants emitted from chimneys of coal-fired power plants are considered to be a major source of fine particulate matter in the atmosphere. In order to manage fine particle in the chimney of a coal-fired power plant, it is necessary to know the concentration of fine particle emitted in real time, but the current system is difficult. In this study, a real-time measurement system for chimney fine particle was developed, and measurements were performed on six coal-fired power plants. Through the measurements, the mass concentration distribution according to the particle size could be secured. All six chimneys showed bimodal distribution, and the count median diameters of each mode were 0.5 and 1.1 ㎛. In addition, it was compared with the gravimetric measurement method, and it was determined that the relative accuracy for PM10 was within 20%, and the value measured using the developed measuring instrument was reliable. Finally, three power plants were continuously measured for one month, and as a result of comparing the concentration of PM10 according to the amount of power generation, it was confirmed that the PM10 discharged from the chimney increased in the form of an exponential function according to the amount of power generation.

Current Conditions of Habitat for Rana catesbeiana and Trachemys scripta elegans Imported to Jeju-do, Including Proposed Management Plans (제주도에 이입된 황소개구리(Rana catesbeiana)와 붉은귀거북(Trachemys scripta elegans)의 서식실태 및 관리방안)

  • Oh, Hong-Shik;Hong, Chang-Eui
    • Korean Journal of Environment and Ecology
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    • v.21 no.4
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    • pp.311-317
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    • 2007
  • This study was conducted to determine the geographical distribution and habitat for Rana catesbeiana and Trachemys scripta elegans in order to obtain the current basic data on biota needed for establishing a database on non-indigenous species(NIS) in Jeju-do and to develop management plans applicable to Jeju, starting from March 2005 until May 2006. As a result of an inspection, it was found that the habitat for R. catesbeiana in Jeju includes Hankyeong-myeon, Daejeong-eup, and Ahndeok-myeon. These areas are all located on the western side of Jeju-do, and considered to have favorable conditions for R. catesbeiana to inhabit. Thus, it is unlikely that the population of R. catesbeiana will possibly decrease; what's worse, there exists even a risk that it could not only expand to other regions but also do damage to the population of native insecta, fishes, amphibians and reptiles, so this terrible species ought to be exterminated. More than 92 individuals of T. scripta elegans species were found to inhabit in 15 ponds around Jeju Island. T. scripta elegans. as the topmost predator, could destruct the pond ecosystem, and also cause a problem of water pollution due to its excrement. Counter-measures against T. scripta elegans could include publicity activities encouraging self-control of the release of captive T. scripta elegans, extermination plans using its ecological habits, and sign-posting publicizing its hazard to healthy ecosystem at the areas with high population density of T. scripta elegans or at its habitats with high foot traffic, together with the continuous management of NIS(none-indigenous species).