• 제목/요약/키워드: Natural source

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국내 비점오염 현황 및 제어방안: 총설 (Assessment and its control of non-point source pollution in Korea: Review)

  • 강민우;이상수
    • 상하수도학회지
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    • 제33권6호
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    • pp.457-467
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    • 2019
  • Because non-point source pollution is very closely related to hydrological characteristics, its importance is highly emphasized nowadays along with accelerating climate change. Especially for Korea, the non-point source pollution and its control are entirely depending on runoff, precipitation, drainage, land use or development, based on geographical and topographical reasons of Korea. Many studies reported the physical (e.g., apparatus- and natural-type facilities, etc.) and chemical methods (e.g., organic and inorganic coagulants, etc.) of controling non-point pollutant source pollution, however, those are needed to be reconsidered along with climate change causing the unexpected patterns and amounts of precipitation and strengthen complexity of social community. The objectives of this study are to assess recent situations of non-point source pollution in Korea and its control means and to introduce possible effective ways of non-point source pollution against climate change in near future.

구획모델을 이용한 주택에서 이산화질소의 발생강도 및 감소상수 동시 추정 (Estimation of Source Strength and Deposition Constant of Nitrogen Dioxide Using Compartment Model)

  • 양원호;손부순;손종렬
    • 한국환경보건학회지
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    • 제31권4호
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    • pp.260-265
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    • 2005
  • Indoor air quality might be affected by source strength of indoor pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate the source strength and deposition constant by application of multiple measurements. For the total duration of 60 days, indoor and outdoor $NO_2$ concentrations every 3 days were measured in 30 houses in Seoul, Asan and Daegu. Using a compartment model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the source strength and deposition constant were estimated. Natural ventilation was $1.80{\pm}0.42\;ACH,\;1.11{\pm}0.50\;ACH,\;0.92{\pm}0.26\;ACH$ in Seoul, Asan and Daegu, respectively. Calculated deposition constant(K) and source strength of $NO_2,$ in this study were $0.98{\pm}0.28\;hr^{1}\;and\;16.28{\pm}7.47\;ppb/h,$ respectively.

바닥충격음 완충재의 동적특성과 소음저감 성능 비교 (Comparison Between the Dynamic Properties and Noise Isolation Performances for a Floor Impact Isolation Pad)

  • 양수영;이동훈;홍병국;송화영;이주원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.275-278
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    • 2005
  • In this study, the dynamic properties of a floor impact sound isolation pad expressed in terms of the natural frequency, the dynamic stiffness per unit area and the loss factor are measured by the resonant method. By using the measured dynamic properties, the vibration transmissibility diagram is obtained for each isolation pad, which is compared with the values tested by the impact sound sources at the room in an apartment. From the comparative results, it is found that the noise reduction Performances. of isolation pads are closely connected with the natural frequency and the dynamic stiffness per unit area.

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강원지역의 산사태 위험지 분포 현황에 관한 연구 (The Study on the Status of Landslide Risk Region in Kangwon-Do)

  • 이승호;이민규;장범수;심정훈
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.846-853
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    • 2005
  • The whole death by disaster is totalized to 1,515 person from 1993 to 2004 year in our country. In this section life damages by landslide is totalized 357 people(about 24% of whole life damage). About 36 people are died by landslide(such as cutting area failure every year). Kangwon-do need a lot of interests and prevention because dangerous area that landslide occurrence is more than other area at summer localized downpour or thawing season and there is landslide occurrence possibility area more than other area. Kangwon-do area is higher than other area in natural disaster incidence and damage scale because topography and a lot of rainfalls by summer localized in Kangwon-Do than other area. In this study, dangerous area of landslide occurrence possibility is analyzed and compared Kangwon-Do with other areas in our country. as a result, every year we have experienced landslide occurrence and natural disaster. accordingly, we urgently need to prevent landslide occurrence and natural disaster by analy-zed source about landslide occurrence and condition of disaster in Kangwon-Do and suitable engineering method and construction work.

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발열체와 부분 열림 수직벽을 갖는 사각 공간 내 자연대류 특성 해석 (A Study on the Characteristics of Natural Convection in a Partially Opened Enclosure with a Heat Source)

  • 심동식;강보선;차동진;주원종
    • 대한기계학회논문집B
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    • 제24권12호
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    • pp.1588-1595
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    • 2000
  • Natural convection heat transfer in an enclosure with an opening in the right veritcal wall and a heat source at the bottom surface is investigated using a holographic interferometric technique. The effects of the opening length, divider length attached to the top wall, and heater temperature on the temperature distribution are examined. The opening length as well as the divider length greatly affects the degree of inflow and outflow of air. In the case of small opening length, the opening doesnt affect much the upward warm air flow resulting in the symmetric temperature distribution .The upward flow in hindered by the divider resulting in the decrease of heat transfer from the heater region to the upper region. The longest divider shows the highest temperature in the lower region of enclosure. In the case of large opening length, the inward cold flow moves the upward flow to the left direction. Among the cases of different divider length, the case of H(sub)d=0.25H shows the highest temperature in the lower region of enclosure.

Isolation of Antimicrobial Substances from Hericium erinaceum

  • Kim, Dong-Myong;Pyun, Chul-Woo;Ko, Han-Gyu;Park, Won-Mok
    • Mycobiology
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    • 제28권1호
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    • pp.33-38
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    • 2000
  • Mycelium of Hericium erinaceum isolate KU-1 was cultured in liquid medium (HL medium) and solid medium (Ko medium) at pH 4.0 in $28^{\circ}C$. 1.0% glucose or fructose was the most favorable carbon source, and 0.2% amonium acetate or $NaNO_3$ was an exellent nitrogen source for mycelial growth as well as production of antimicrobial substances. The mixture of saw dust 70% with rice bran 30% (SR medium) was the substrate for formation of sporophores. The active substrates in extracts from mycelium, culture filtrate and fruiting body were separated by TLC. The solvent for TLC was EtOAc: Chloroform: MeOH (10 : 5 : 10). Phenol-like substances appeared at Rf $0.5{\sim}0.9$, and fatty acid-like substances appeared at Rf $0.1{\sim}0.2$. The purified materials from the extracts showed antimicrobial effects to Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, Candida albicans and Microsporum gypseum. The S. aureus was the most inhibited. Minimal inhibitory concentration (MIC) of purified white powder and the Hercenone derivatives against S. aureus were $5.65\;{\mu}g/ml$ and $1.85\;{\mu}g/ml$, respectively.

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Molecular Mechanism of Inflammatory Signaling and Predominant Role of Saposhnikovia divaricata as Anti-inflammatory Potential

  • Khan, Salman;Kim, Yeong Shik
    • Natural Product Sciences
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    • 제19권2호
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    • pp.120-126
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    • 2013
  • Natural products have always been a pivotal source of new drug development. Dry roots of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae) is a perennial herb and is also known as Bang Pung in traditional medicine. Numerous in vitro and in vivo studies have revealed the diverse pharmacological effects of S. divaricata and its role in the treatment of various diseases. This herb has exhibited significant inhibitory effects against inflammation and associated disorders. The present study explored the ethnopharmacological applications and molecular mechanisms behind the anti-inflammatory effects of S. divaricata herb and a single compound blockade of multi-signaling inflammatory cascades. Taken together, this review provides insight into the potential role of S. divaricata against various inflammatory diseases.

Phytochemical Constituents of Geranium eriostemon

  • Chang, Sang-Wook;Kim, Ki-Hyun;Lee, Il-Kyun;Choi, Sang-Un;Lee, Kang-Ro
    • Natural Product Sciences
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    • 제15권3호
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    • pp.151-155
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    • 2009
  • Phytochemical investigation of the MeOH extract of the aerial parts of Geranium eriostemon resulted in the isolation of one triterpene, three furofuran lignans, one syringic acid and four flavonoids. Their chemical structures were characterized by spectroscopic methods to be oleanolic acid (1), (-)-kobusin (2), (-)-eudesmin (3), (+)-magnolin (4), syringic acid (5), quercetin (6), juglanin (7), juglalin (8), and hyperin (9). All compounds (1 - 9) were isolated for the first time from this plant source and the compounds 2 - 4 were reported first from the genus Geranium. Compounds 4 - 6 exhibited moderate cytotoxicity against four human cancer cell lines in vitro using a SRB bioassay.