• Title/Summary/Keyword: Characters of Water

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골프장 답압지역의 토양개량 (Effect of Soil Amendments at Heavy Traffic Area in Golf Course)

  • 태현숙;김용선;고석구
    • 한국조경학회지
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    • 제27권5호
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    • pp.107-113
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    • 2000
  • The purpose of this study is to investigate the effects of soil amendments for reducing soil compaction at heavy traffic area in golf course. Major results of this research are summarized at follows: 1. In the Lab. experiment, the porosity was improved significantly when the materials, such as peatmoss, charcoal, and tire chip mixtures were used respectively. Especially mixture of sand and 20% peatmoss showed higher effectiveness (10%) in porosity, comparing with ordinary sand. This soil mixture(sand 80%+peatmoss 20%) was observed the best in water retention, soil hardness and hydrauric conductivity. 2. In the greenhouse experiment, traffic pressure was given 7 times a day on several combination of mixture treatments to see the top dry weight. The soil mixture of 20% peatmoss showed the highest in the top dry weight. When the more traffic pressure(15 time/day) were given on the different treatment, the top dry weight was significantly reduced. However, the mixture of 20% peatmoss also had the least influence on this type of heavy traffic. 3. In the field experiment, the soil amendments were treated in traffic area f golf course, and observed at 30days, 60days, 90days, 120days after treatment. Visual turf quality(color), root length and soil compaction were compared to those of control. As a result, overall treatments with soil amendments were effective, which showed better turf quality and less soil compaction. 4. In the field test, physical characters of soil (such as soil hardness and hydrauric conductivity) in sand+tire chip+peatmoss(60:20:20, %, v/v) treatment was significantly improved. Also in the slow increasing of traffic, the soil compaction was the most effective in reducing soil hardness.

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Development of a thermo-stabel ${\beta}-agarase$ from marine organism

  • Lee, Sang-Hyeon
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVI)
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    • pp.31-32
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    • 2005
  • Neoagaro-oligosaccharides are produced only by enzymatic degradation of agarose by ${\beta}-agarase.^{1)}$ Neoagaro-oligosaccharides inhibit the growth of bacteria, slow the rate of degradation of starch, are used as low-calorie additives to improve food quality, and have macrophage-stimulating activity. Furthermore, neoagarobiose is a rare reagent that has both moisturizing effect on skin and whitening effect on melanoma $cells.^{2)}$ An agar-degrading marine bacterium was isolated from the sea water at the northeast coast in Cheju island, Korea. The strain was gram negative, aerobic, and motile rod. The 16S rRNA of the strain had the closest match of 98% homology, with that from Agarivorans albus. On the basis of several phenotypic characters and a phylogenetic analysis, this strain was designated Agarivorans sp. JA-1. In solid agar plate, Agarivorans sp. JA-1 produced a diffusible agarase that caused agar softening around the colonies. Agarivorans sp. JA-1 was cultured for 36 hr in marine broth 2216 (Difco, USA) and the supernatant that containing an extracellular ${\beta}-agarase$ was prepared by centrifugation of culture media. The enzyme exhibited relatively strong activity at $40^{\circ}C$ and was stable up to $60^{\circ}C$. Using PCR primers derived from the ${\beta}-agarase$ gene of Vibrio sp., the gene encoding ${\beta}-agarase$ from Agarivorans sp. JA-1 was cloned and sequenced. The structural gene consists of 2931 bp encoding 976 amino acids with a predicted molecular weight of 107,360 Da. The deduced amino acid sequence showed 99% and 34% homology to $agaA^{2)}$ and $agaB^{2)}$ genes for ${\beta}-agarase$ from Vibrio sp., respectively. The expression plasmid for ${\beta}-agarase$ gene of Agarivorans sp. JA-1 is being constructed and the recombinant enzyme will be biochemically characterized.

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사과의 역병: Ⅰ. Phytophthora cactorum에 의한 줄기역병의 발생 (Phytophthora Diseases of Apple in Korea: Ⅰ. Occurrence of a Destructive Collar Rot Caused by P. cactorum)

  • 지형진;조원대;김완규
    • 한국식물병리학회지
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    • 제13권3호
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    • pp.139-144
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    • 1997
  • 사과 줄기 밑둥을 썩히는 역병 (collar rot)이 경북의 사과 재배지역에 널리 발생하고 있으며, 충북, 충남, 전북 등의 일부 지역에서도 발생이 확인되었다. 이 역병은 주로 M26이나 M9를 왜성대목으로 사용한 후지품종에 심하게 발생되었는데, 발병율은 포장에 따라 큰 차이를 보이지만 의성, 군위, 예산, 무주 등지의 일부 포장에서는 이병주율이 45~80% 정도로 아주 높았다. 수집된 25 균주의 균학적 특성을 조사 결과 모두 Phytophthora cactorum으로 동정되었는데, 이들은 배지에서나 물 속에서 유두돌기가 뚜렷하며, 계란형의 쉽게 이탈되는 다량의 유주자낭을 형성하였고 짧은 자루 (약 4 ${\mu}m$)를 부착하고 있었다. 자웅동주 균으로 10% clarified V8 배지에서 다량의 난포자를 형성하였는데 모든 장정기는 측착 (paragynous) 하였다. 모든 공시 균주는 5$^{\circ}C$ 이하와 33$^{\circ}C$ 이상에서는 자라지 못하였으며 난포자도 형성되지 않았다. Phytophthora cactorum에 의한 사과 줄기역병은 국내에서 기록된 바가 없어 본 병해를 최초로 보고하는 바이다.

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온천 주변 소형하천에 서식하는 부착조류군집에 관한 연구 (A Study on the Epilithic Algae in a stream drained from Hot Springs)

  • 최환석;유춘만
    • 한국환경보건학회지
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    • 제24권3호
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    • pp.131-136
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    • 1998
  • Attached algal community and several physico-chemicai characters were investigated at Seokjong hot spring in Chollabukdo in February and in April, 1997. The results of physico-chemicai factors are as follows : water temperatures were varied from 6.5$^{\circ}$C to 32.0$^{\circ}$C; pH range was 6.9 to 7.7; The levels of electric conductivity were 105 $\mu$mhos/cm to 477 $\mu$mhos/cm; chemical oxygen demand(COD) range was 1.5 mg/l to 21.2 mg/l; ammonia concentration was 0.20 mg/l to 8.74 mg/l; nitrate concentrations were 0.36 mg/l to 2.43 mg/l; phosphate concentration was N.D. to 0.52 mg/l; sulfur concentration was 14.6 mg/l to 66.1 mg/l. Attacched algal species were identified. Totally, 63 taxa were classified and composed of 4 phylum, 4 class, 10 order, 17 family and 31 genera. The total biomass of attacched algae was $1.036 \times 10^{7}$ cells/l that composed of $5.39 \times 10^{6}$ cells/l of blue-green algae, $4.05 \times 10^{6}$ cells/l of diatom and $0.93 \times 10^{6}$ cells/l of green algae. The succession of dominant species was Synechocystis thermalis. This could be due to the thermal wastewaters. in biotic indices tests, the values of dominance index(DI) were 0.33 to 0.67 in winter, 0.18 to 0.68 in spring. The values of diversity index(H') were 1.44 to 2.69 in winter, 1.62 to 2.89 in spring. And the values of eveness index (J) were 0.31 to 0.61 in winter, 0.37 to 0.65 in spring.

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노래미의 난발생과 부화자어 (Eggs Development and Larvae of Rock-trout, Agrammus agrammus(Temminck et Schlegel))

  • 김용억;명정구
    • 한국수산과학회지
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    • 제16권4호
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    • pp.395-400
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    • 1983
  • 1982년 11월 18일 부터 25일 사이에 해운대 동백섬에 위치한 부산수산대학 해양과학연구소 앞 연안에서 주낚으로 채집된 성숙한 노래미를 이용하여 실험실내에서 인공수정에 의한 난발생과정과 부화자어에 관하여 관찰한 결과를 요약하면 다음과 같다. 난은 구형이며 침성점착난으로 난경은 $1.92{\sim}2.14mm$로 짙은 황색의 유구가 무수히 존재한다. 실내수온 $11.8{\sim}17.9^{\circ}C$(평균 $14.2^{\circ}C$)에서 수정후 463시간만에 부화하였다. 부화직후의 자어는 전장 $6.55{\sim}8.2mm$이며 근절수 12+36=48. 난황의 전단에 큰 유구가 하나 있다. 부화후 3일째의 전장 7.8mm의 자어는 꼬리부분의 $13{\sim}19$번째의 근절부분에 $4{\sim}5$개의 흑색소포 나타난다.

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벼 건답직파 재배시 중간낙수가 생육 및 도복에 미치는 영향 (Influence of Midsummer Drainage on Growth and Lodging of Rice in Direct Seeding on Dry Paddy)

  • 최민규;김상수;이선용;최선영
    • 한국작물학회지
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    • 제40권5호
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    • pp.574-579
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    • 1995
  • 건답직파 재배시 중간낙수처리가 도복에 미치는 영향을 구명하고자 1991년에 동률벼를 공시, 5월 1일에 휴립 세조파하고, 파종후 30일에 심수하고 심수후 20일 부터 10일 간격으로 1∼3회 낙수처리하여 도복관련형질 및 수량을 검토한 결과를 요약하면 다음과 같다. 1. 간장 및 절간장은 낙수회수가 많을수록 짧아지고 간벽은 두꺼워졌으나, 줄기 굵기는 상시심수에서 다소 굵었다. 2. 낙수회수가 많을수록 중심고는 낮아지고 좌절중은 무거워서 도복지수는 적어졌으며, 낙수회수가 많을수록 뿌리량이 많아지고 뿌리의 심층분포비율이 높아지는 경향이었다. 3. 도복은 상시심수에서는 심하게 발생되었으나 낙수회수가 많을수록 경감되어 2∼3회 낙수처리에서는 도복이 발생되지 않았거나 경징하였다. 4. 수량은 등숙후기(출수후 35일)에 도복이 발생되어 상시심수와 낙수처리간에 차이가 없었으나, 현미중의 청미비율은 낙수회수가 많을수록 감소되는 경향되었다. 5. 따라서 건답직파 재배시 심수후 20일부터 10일간격으로 2∼3회 중간낙수 처리하는 것이 도복방지를 위한 적절한 물관리 방법이라고 생각된다.

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초음파를 이용한 해저면 판독 시스템에 관한 연구 (A Study on Seabed Interpretation System Using Supersonic Waves)

  • 김재갑;김원중;황두진
    • 한국정보통신학회논문지
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    • 제5권2호
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    • pp.385-391
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    • 2001
  • 본 연구는 해저면의 뻘, 모래, 자갈, 패류 등을 초음파를 이용하여 형태별로 신호패턴을 데이터베이스로 구축한 후, 바다 현장에서 어군탐지기에 수신된 아날로그 신호를 A/D변환기를 사용하여 디지털 신호로 변환하고, 이 신호를 컴퓨터에서 가공, 분석한 후 DB에 있는 신호패턴과 실시간으로 비교하여 해저면 목표물을 인식할 수 있는 판독시스템을 개발하는 것이다. 지금까지 연구한 결과를 바탕으로 많은 실험을 거친 후(수조 및 현장 실험 등) 침전물의 데이터를 세밀히 샘플링하여 분석하면 해저면의 저질 상태 및 침전물들의 정확한 정보를 알아낼 수 있다. 또한, 수중에서 어종별로 어체에서 반사되는 초음파 특성과, 해저면에서 뻘과 딱딱한 패류 껍질, 모래, 자갈 등에서 반사되는 초음파 특성 등을 1차 신호와 2차, 3차 신호들에 대한 성분을 분석하여, 해저 목표물을 나타내는 1차 신호의 필요한 값은 추출하고, 그 외의 2차, 3차 신호는 필터링 시키는 해저면 판독시스템을 개발하는 것이다.

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Growth and Cultural Characteristics of Cordyceps cardinalis Collected from Korea

  • Sung, Gi-Ho;Shrestha, Bhushan;Han, Sang-Kuk;Kim, Soo-Young;Sung, Jae-Mo
    • Mycobiology
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    • 제38권4호
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    • pp.274-281
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    • 2010
  • Cordyceps cardinalis was reported in Japan and the USA in 2004, and its fruiting bodies have recently been cultured in Korea. Herbarium specimens preserved at the Cordyceps Research Institute, Mushtech, Korea were revised and identified as C. cardinalis, based on morphological characters and conidial structures. Most of the C. cardinalis specimens were collected from Mt. Halla in Jeju-do. The effects of various nutritional sources and environmental conditions such as temperature and pH on mycelial growth of C. cardinalis were studied. Oatmeal agar, Martin's peptone dextrose agar, and Schizophyllum (mushroom) genetics complete medium plus yeast extract resulted in the best mycelial growth. Among carbon sources, cereals, and nitrogen sources, maltose, oatmeal, and peptone resulted in the best mycelial growth respectively. Mineral salts helped to increase growth rate but only resulted in thin mycelial density, similar to water agar. A temperature of $25^{\circ}C$ and a pH of 7 resulted in the highest mycelial growth. Based on these results, a Cordyceps cardinalis composite medium (CCM) was formulated with 1% maltose, 2% oatmeal, 1% peptone, and 2% agar. Use of the CCM resulted in slightly better mycelial growth than that of other commonly used agar media. Only organic nitrogen sources imparted a reddish pigmentation to the agar media, but this character diminished after several subcultures. A 7 day culture duration resulted in the best mycelial growth.

라이트의 주택에 나타난 대지와 하늘의 인식에 관한 연구 (Frank Lloyd Wright's Houses in relation to the Earth and the Sky)

  • 김태영
    • 한국농촌건축학회논문집
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    • 제18권3호
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    • pp.1-8
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    • 2016
  • Frank Lloyd Wright(1867-1959) had the confident concept that architecture should be at home in nature. His architecture was meant to bear an intimate relation to the earth and the sky, and should look as though it began there at the ground and contrasted with the sky. In handling all the details of house design elements, his efforts for being married to the ground was to conceive the void of the sky. This study is to research his thinking process and its development to the earth and the sky, and to analyze how such thought could reflect his houses. The mass of house are divided into three parts such as the foundation or base, body, and roof. These parts are respectively related to the earth and the sky. This study goes on regarding them as an analytical framework. The subjects of study are the Prairie houses in the early 20th century and the Usonian houses after 1930's. As results of this study, the earlier foundation as a platform appeared as a base and water table, and a strong baseline pressed the structures into the soil in the Prairie houses. The direct contact of wood and brick to ground were dominant details after Wiley house(1934). The base was almost invisible to the eye in the Usonian houses. Secondly, the pierlike shapes and delicate friezes of walls were anchored to the ground, and horizontal bands as trims or copings also got close to the earth. These characters had disappeared after the Allen house(1917), all components including exterior walls had been unified with the grid patterns in the Usonian houses. Thirdly, the overhanging cantilever roof had got to the earthbound by the reflection of shadow as well as their evident horizontal. He lowered the roof, lengthened and brought it closer to the ground. In this way, Frank Lloyd Wright intended his houses to be at home in nature. And also he tried to bind the houses to the earth and contrasted them with the sky. The houses would perform their highest function in relation to the earth and sky.

토지피복 변화가 도시열수지에 미치는 영향에 관한 수치시뮬레이션 (Numerical Simulation on the Effect of the Land Coverage Change on the Urban Heat Budget)

  • 김상옥;여인애;한경민;이정재;윤성환
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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    • pp.176-179
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    • 2009
  • In this study, Urban Climate Simulation was performed using 3-Dimensional Urban Canopy Model. The characteristics of urban thermal environment was analyzed by classifying land coverage and increasing natural land coverage ratio. The results are as follows. The characteristics of the land coverage on urban thermal environment formation can be summarized by the effects like higher temperature on the artificial coverage, and the contrary effects on the natural coverage. When the water coverage 100% was made up, maximum temperature was declined by $5.5^{\circ}C$, humidity by the 6.5g/kg, wind velocity by 0.6m/s, convective sensible heat by $400W/m^2$ and the evaporative latent heat was increased by $370W/m^2$ compared to when artificial coverage 100% was formed. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analysing urban climate phenomenon.

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