• Title/Summary/Keyword: Gan

Search Result 888, Processing Time 0.028 seconds

Characteristics of Atmospheric Speciated Gaseous Mercury in Chuncheon, Korea (춘천시 대기 중 가스상 수은 종 농도 특성에 관한 연구)

  • Gan, Sun-Yeong;Yi, Seung-Muk;Han, Young-Ji
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.31 no.5
    • /
    • pp.382-391
    • /
    • 2009
  • Atmospheric speciated mercury concentrations including total gaseous mercury (TGM) and reactive gaseous mercury (RGM) were measured in Chuncheon from March 2006 to November 2008. Average concentrations were 2.10 ${\pm}$ 1.50 ng/$m^3$ and 3.00 ${\pm}$ 3.14 pg/$m^3$ for TGM and RGM, respectively. RGM concentrations were higher during daytime than nighttime probably because of high photochemical activities. We found that RGM concentration considerably increased as ozone increased when fog occurred, indicating that ozone was the important oxidant for $Hg^0$ in aqueous phase. TGM concentration showed positive correlations with CO and $PM_{10}$ which can transport in long-range, but there was no correlation with $NO_2$. Considering that major source of mercury is combustion process, this result showed that local sources did not significantly impact on TGM concentration in Chuncheon. Five-day backward trajectories were calculated for the samples representing high and low concentrations of TGM, and determined that industrialized area of China including Shenyang and Beijing influenced TGM concentrations in Chuncheon.

Dependence of 0.01M CaCl2 Soluble Phosphorus on Extractable P and P Sorptivity in Upland Soil (밭토양(土壤)에서 유효린산함량(有效燐酸含量)과 인산흡수능(燐酸吸收能)에 따른 0.01M CaCl2 가용(可溶) 인산농도(燐酸濃度) 변화(變化))

  • Yoon, Jung-Hui;Jung, Beung-Gan;Kim, Yoo-Hak
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.31 no.3
    • /
    • pp.266-270
    • /
    • 1998
  • The identification of soil P level that exceed crop requirement is a prerequisite in implementing sustainable management of fertilizer and manure P to prevent soil and freshwater from contamination. To investigate the relationship between 0.01M $CaCl_2$ soluble P, and available P and P sorption capacity of 40 soils, P content and P sorptivity were analyzed. Single linear relationship revealed the dependence of 0.01M $CaCl_2-P$ on available P($r^2=0.479$), bioavailable P($r^2=0.281$), P sorption($r^2=-0.465$) and P absorption coefficient($r^2=-0.056^{NS}$). Thus available P as $P_2O_5$(AVP) and P sorption (PS) were most important factors in determining the concentration of 0.01M $CaC1_2-P$($CaC1_2-P$). In multinomial equation related $CaC1_2-P$ with AVP and PS, the determination coefficient was improved to 0.745. The logarithm of $CaC1_2-P$ was linearly related to AVP/PS. Consequently, the equation, $0.01M\;CaCl_2-P=0.1284e^{0.3288AVP/PS}$ could be suggested to estimate the concentration of P in 20mL of 0.01M $CaCl_2$ solution containing 2g of soil shaken for 17 hours.

  • PDF

Monitoring on Chemical Properties of Bench Marked Paddy Soils in Korea (우리나라 논토양(土壤)의 화학적(化學的) 특성(特性) 분석(分析))

  • Jung, Beung-Gan;Jo, Guk-Hyun;Yun, Eul-Soo;Yoon, Jung-Hui;Kim, Yoo-Hak
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.31 no.3
    • /
    • pp.246-252
    • /
    • 1998
  • A survey was conducted to investigate the status of soils involving pH, electrical conductivity, total organic matter content, available phosphate and major exchangeable cations in the paddy soils sampled from 1,168 sites throughout the country. The content of soil chemical properties was lower on the average than the optimum levels for cropping. An average value showed pH 5.6, organic matter $25g\;kg^{-1}$, available phosphate $128mg\;kg^{-1}$, available silicate $72mg\;kg^{-1}$, and exchangeable potassium and the calcium and magnesium were 0.32, 4.0, $1.2cmol^+\;kg^{-1}$, respectively. Soil chemical properties was related with topography except soil pH. A soil pH and organic matter, available phosphate, exchangeable potassium increased with time while exchangeable calcium, magnesium available silicate decreased with time.

  • PDF

Characteristics of selective area growth of GaN/AlGaN double heterostructure grown by hydride vapor phase epitaxy on r-plane sapphire substrate (HVPE 방법에 의해 r-plane 사파이어 기판 위의 선택 성장된 GaN/AlGaN 이종 접합구조의 특성)

  • Hong, S.H.;Jeon, H.S.;Han, Y.H.;Kim, E.J.;Lee, A.R.;Kim, K.H.;Hwang, S.L.;Ha, H.;Ahn, H.S.;Yang, M.
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.19 no.1
    • /
    • pp.6-10
    • /
    • 2009
  • In this paper, a selective area growth (SAG) of a GaN/AlGaN double heterostructure (DH) has been performed on r-plane sapphire substrate by using the mixed-source hydride vapor phase epitaxy (HVPE) with multi-sliding boat system. The SAG-GaN/AlGaN DH consists of GaN buffer layer, Te-doped AlGaN n-cladding layer, GaN active layer, Mg-doped AlGaN p-cladding layer, and Mg-doped GaN p-capping layer. The electroluminescence (EL) characteristics show an emission peak of wavelength, 439 nm with a full width at half maximum (FWHM) of approximately 0.64 eV at 20 mA. The I-V measurements show that the turn-on voltage of the SAG-GaN/AlGaN DH is 3.4 V at room temperature. We found that the mixed-source HVPE method with a multi-sliding boat system was one of promising growth methods for III-Nitride LEDs.

Study on 『BianZhengGiMun)』's medical characteristics - In view of ShangHan - (『변증기문(辨證奇聞)』의 의학적(醫學的) 특징(特徵)에 관(關)한 고찰(考察) -상한문(傷寒門)을 중심(中心)으로-)

  • Lee, Won-Suk;Park, Sun-Dong;Park, Won-Hwan;Kim, Jun-Ki;Kim, Jong-Dae
    • The Journal of Dong Guk Oriental Medicine
    • /
    • v.6 no.2
    • /
    • pp.33-85
    • /
    • 1998
  • In order to find the characteristic medical methods of "BianZhengGiMun" by the author ChenShihTo, we have translated and analyzed the mentioned book. Upon analyses, the following facts were noted : 1) "BianZhengGiMun" is written and composed of case studies. Prescriptive methods described here differ rather from previously known methods, where as our nation's Oriental medicine practitioners refer and consider these methods as miraculous modern methodologies. 2) Book's content has much similarities to "ShangHanLun"'s original text. Moreover, the content is adjusted towards presenting methodologies not coverd in "ShangHanLun"'s text, together with adding more information to conserve "ShangHanLun"'s methods as well as to critique them. 3) Diagnostic methods mainly follow the ZangFuBianZheng(臟腑辨證)'s pattern, where it's recorded information and theories are valid. 4) "BianZhengGiMun"'s proscriptive methods usually follow BuYinShengJin(補陰生津)'s form, where they were appropriate for that period and circumstances. 5) In consideration of all of the above factors, ChenShihTo grasped ShangHan and WenBing(acute febrile disease due to exogenous factor) as WaiGanReBing(外感熱病)'s double sided characteristics, where this corresponds with the current belief. It is believed that this in turn would provide much practical value to the present time.

  • PDF

Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery (바나듐 레독스-흐름 전지에서 집전체의 전기화학적 특성)

  • Hwang, Gan-Jin;Oh, Yong-Hwan;Ryu, Cheol-Hwi;Choi, Ho-Sang
    • Korean Chemical Engineering Research
    • /
    • v.52 no.2
    • /
    • pp.182-186
    • /
    • 2014
  • Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of $60mA/cm^2$. The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was $4.44{\sim}5.00{\Omega}{\cdot}cm^2$ and $3.28{\sim}3.75{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was $4.19{\sim}4.42{\Omega}{\cdot}cm^2$ and $4.71{\sim}5.49{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

Air Temperature And Leaf Growth of Several Woody Plants in Early Gruwing Season (수 종 목본식물의 생육초기 기온과 잎의 생장)

  • 민병미
    • The Korean Journal of Ecology
    • /
    • v.17 no.1
    • /
    • pp.49-58
    • /
    • 1994
  • To investigate the relationship between leaf growth of several woody plants and ait tempera ture in early growing season (from April to June) in deciduous forests, I surveyed the changes of leaf area (LA), leaf weight (LW) and specific leaf area (SLA) of 19 specles, in two areas Namhansansung (NA) and Taegwallyong (TA) area in which that the latitudes are similer ($37^{\circ}28'N$ at NA and $37^{\circ}27'N$ an TA), but annual mean-temperatures were different ($11.8^{\circ}C\;in\;NA, \;6.3^{\circ}C$ in TA) for two years, 1991 and 1992. In the same species, the plants of NA began to grow 10-25 days earlier than those of TA, but the latter grew faster than the former. On 10 June the values of LA and LW per leaf were similar in the two areas but the maximum values of SLA were higher in NA. In the same plant, the values of LA and LW were constant year by year, except for PYIOLUS leveilleana, Quercus mongolica, Symplocos chznensis for. pilosa and S t y a r ubussiu. In N A , the leaves be gan to grow during the first ten days of April, and eariler in 1992 than in 1991, and daily mean temperature (DMT) of the former from 27 March to 6 April were higher than those of thc latter. But the LA increased faster in 1991 than in 1992. and DMT from 10 April to 16 April were higher in 1991 than in 1992.

  • PDF

Design of Mobile Agent Management System based on OSGi (OSGi 기반 이동 에이전트 관리 시스템 설계)

  • Lee, Seung-Keun;Kim, In-Tae;Kim, Tae-Gan;Lee, Kyoung-Mo;Rim, Ki-Wook;Lee, Jung-Hyun
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.42 no.5
    • /
    • pp.41-48
    • /
    • 2005
  • OSGi(Open Service Gateway Initiative) offers a unique opportunity for pervasive computing as a potential framework for achieving interoperability between various sensors, home appliances, and networked devices. The OSGi framework supports a remote installation of a bundle, which is a unit that installs and deploys services. However, in order for the bundle in execution to migrate, a specific form of bundle such a mobile agent, is needed one which is able to move through a heterogeneous network. This paper proposes a method that can manage bundles like these dynamic agents, in order to ensure the mobility of entities in multiple OSGi framework environments. For our purposes, we have designed the mobile agent management system for managing the lifecycle and mobility of agents in the OSGi framework. The mobile agent management system we are proposing implements a bundle form which can perform in an OSGi framework as well as manage autonomous mobile services. As a result, mobility in a pervasive environment will be supported more efficiently.

A Study on the Development of men's Wear in Korea (남성복의 변화에 관한 연구)

  • 이순홍
    • Journal of the Korean Society of Costume
    • /
    • v.29
    • /
    • pp.5-22
    • /
    • 1996
  • the present thesis aims to contribute to the further development of the men's wear indus-try in Korea which now confronts the need to adjust itself more actively to the conditions of the coming age of internationalization and free trade. To achieve this this thesis suggests the trade should provide for the changing domestic needs on theone hand and refine its wares as high value-added products in compe-tition with those from the advanced countries in fashion industry on the other, The history of the 'suit' the standard men's attire dates back to 1850 when the 'Ditto suit' was introduced composed of coat waist coat vest and trousers to remain virtually unchanged till the end of the nineteenth cen-tury and the modern men's wear originated in Britain. In Korea since the introduction of western clothes from 1876 custom-made suits had been dominant until 1944 while western clothes earned popular currency between 1945 and 1964 and ready-made suits began to spread with their advantages recognized in terms of practicality convenience and functionality The next phase from 1965 to 1985 witnessed the establishment of a number of ready-made brands although custom-made suits stayed in their height of prosperity until 1975. The turn-ing point for the men's wear industry came in 1975 when high-calss ready-made brands be-gan to turn up with the arrival of large companies in the market matching the change in consumers' life style. The men's wear market went through further diversification and specialization dur-ing the years between 1985. and 1990. Around the year 1990 however the expansion of the business suit industry came to slow down ac-companied by an oversupplied market. The fashion of pragmatism in the 1990s called for the growth of the casual wear department and as consumers' life style became more and more individualized conscious dressing in accord ance with T.P.O established itself as an important branch of culture, Such casual boom is likely to aid in promoting Korea's men's wear indus-try to peer with that of advanced countries. Consumers' fashion sense is now ahead of the trade's as well as being shortcycled highly individualized stylized and diversified. To meet consumers' demands under such circum-stances each company is required to develop its unique soft Know How based on accurate information and strategically specialized plan-ning. The trade should convert its hithero producer-oriented strategy to a new consumer oriented one and actively lead the needs and purchasin g pattern of consumers by providing an efficient and reasonable price policy with optimum supply of merchandise and also by presenting 'our' trend suited to our circum-stances.

  • PDF

Regular Endurance Exercise Decreases Blood Pressure via Enhancement of Angiogenesis and VEGF Expression in Spontaneously Hypertensive Rats (규칙적인 지구성운동이 고혈압쥐 골격근의 혈관생성과 VEGF 발현의 증가를 통한 혈압감소에 미치는 효과)

  • Li, Wei;Park, Hee-Geun;Lee, Young-Ran;Jang, Hak-Young;Choo, Sung-Ho;Lee, Young-Hwa;Gan, Li;Jun, Jong-Kui;Lee, Wang-Lok;Lee, Sang-Ki
    • Journal of Life Science
    • /
    • v.22 no.5
    • /
    • pp.665-670
    • /
    • 2012
  • This study investigated the effect of endurance exercises on blood pressure, angiogenesis, and the vascular endothelial growth factor (VEGF) expression in the skeletal muscle of spontaneously hypertensive rats (SHR). Five week old SHRs and Wistar-Kyoto rats (WKY) were randomly divided into 3 groups: Wistar-Kyoto rats (WKY, n=9), SHR control (SHR-C, n=9), and SHR endurance exercise training (SHR-E, n=9). Endurance exercise training was performed on a treadmill (12-20 m/min, 0% grade, 60 min/day, 5 days/week, 16 weeks). Systolic blood pressure was monitored with the tail-cuff method. The expression of VEGF protein and capillary density were identified using western blotting and H&E staining in the soleus muscle, respectively. Systolic blood pressure was reduced by endurance exercise in SHR ($p$ <0.05). The capillary density of skeletal muscles in SHR-C was lower than in WKY ($p$ <0.05), but it was recovered by endurance exercise training (SHR-E) compared to SHR-C ($p$ <0.05), and VEGF protein was also increased by endurance exercise training compared to SHR-C ($p$ <0.05). These data suggest that the enhancement of capillary density via an increase of VEGF expression in skeletal muscles by endurance exercise training could be an important factor to inhibit blood pressure elevation in SHR.