• 제목/요약/키워드: Witch

검색결과 141건 처리시간 0.029초

담배장님노린재에 의한 오동나무 빗자루병 MLO의 일일초로의 전반 (Insert Transmission of Paulownia Witches'-Broom Mycoplmsma-Like Organism to Periwinkle Plant by Tobacco Leaf Bug, Cytropheltis tenuis Reuter)

  • 나용준;박원철
    • 한국식물병리학회지
    • /
    • 제10권3호
    • /
    • pp.211-214
    • /
    • 1994
  • Paulowina witches'-broom mycoplasma-like organism (PWB-MLO) was transmitted experimentally to periwinkle (Catharanthus roseus L.) plant by tobacco leaf bug (Cyrtopeltis tenuis Reuter). Adults of the leaf bugs were allowed to feed on the witch's-broom infected paulownia (Paulownia tomentoas Steud.) trees for three weeks to insure the acquisition of PWB-MLO and then transferred to healthy seedlings of periwinkle and paulownia plants. In 25∼35 days after transfer of the viruliferous leaf bugs, six out of the ten periwinkle plants showed‘little-leaf’symptoms, while the paulowina seedlings remained symptomless. Presence of MLO in the infected periwinkle tissue was diagnosed by fluorescence microscopy and MLO particles were observed under electron microscope, confirming the transmission of PWB-MLO to periwinkle.

  • PDF

연돌 효과를 이용한 태양열 굴뚝의 자연환기 성능에 관한 연구 (A Study on the Performance of Natural Ventilation of Solar Chimney Using Stack Effect)

  • 조성우;이재윤
    • 한국태양에너지학회 논문집
    • /
    • 제21권2호
    • /
    • pp.35-43
    • /
    • 2001
  • The results of numerical simulation on the performance of a solar chimney system in building are described. The inside surface temperature of four walls within the solar chimney arc calculated with solar radiation and outdoor temperature in summer. The air within the solar chimney is heated by conduction, convection and radiation. Air temperature distribution from the bottom to the top and outlet air temperature can be obtained by solving energy balance equation. Since the buoyance or stack effect is affected by temperature difference between the bottom and the top within the solar chimney. It is evaluated using inlet and outlet temperatures. It is expected that natural ventilation by the solar chimney of witch the height is 7.8m and the cross sectional area is $4.93m^2$ can provide about $6400m^3/h$ on sunny day.

  • PDF

Protein-based bio-plastics: formulation, processing, properties and applications

  • Guilbert Stephane;Gontard Nathalie;Morel Marie Helene
    • 한국고분자학회:학술대회논문집
    • /
    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
    • /
    • pp.357-357
    • /
    • 2006
  • Many industrial sources of proteins can be used as raw materials to produce films, molded materials, and various hollow items either by "casting" techniques or by "thermoplastic processing". Combining proteins with natural fibbers, paper or biodegradable polyesters is very promising to form biodegradable composites witch take advantage of the barrier and mechanical properties of each component. Using nano-fillers to form nanocomposites has also been shown to be interesting to improve properties. Production, with low transformation cost, of protein based materials to form biodegradable materials with controlled functional properties for food uses, medical uses, packaging, agriculture, controlled release systems, etc. is discussed.

  • PDF

유압모터 구면 정압베어링의 마찰특성에 관한 연구 (The study on the friction characteristics of spherical hydrostatic bearing for hydraulic piston motor)

  • 함영복;최영호;김성동
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2001년도 춘계학술대회 논문집
    • /
    • pp.647-650
    • /
    • 2001
  • In case of bent axis type axial piston hydraulic pump or motor, hydrostatic bearing used to achieve the lubrication effect on the mechanical sliding contact areas between the following pairs ; piston shoe and swash plate, valve plate and cylinder block, piston and cylinder block, etc. In this research, we designed two pairs of spherical ball joint in witch connecting rod piston end. The one is not hydrostatic bearing, the other is designed with spherical hydrostatic bearing in point of view minimum pumping power loss. By varying supply pressure on the piston, we can know that it is possible to reduce the friction torque by using hydrostatic bearing designed one. Finally, by comparing the results of driving torque between the two models, it was verified that the spherical hydrostatic bearing is well designed.

  • PDF

임대주택 주동계획의 사회통합적 증진에 대한 임차인 반응 연구 (A syudy on Renter's Response to Plannin of National Rental Housing for Improving Social Integration)

  • 김경연;이연숙;박민아;허윤경
    • 한국주거학회:학술대회논문집
    • /
    • 한국주거학회 2008년 추계학술발표대회 논문집
    • /
    • pp.102-107
    • /
    • 2008
  • The National Rental Houring has been built for solving the lack of house for the low-income group. However the national rental housing that the low-income group didn't feel aliention' we should improve the quality of National Rental housing. The purpose of this study aims to identify the facts for improving the social integra as the preference of Rental lived in Gwangju. The findings are as follows. The residents had marginal characteristics such as low income, the aged and were satisfied with the residential environment so they want to stay there as long as they can. However, they were dissatisfied with the scale of housing, housing facilities. Therefore, It is important to improve housing condition witch they enhance their self existence.

  • PDF

지름두께비를 고려한 콘크리트충전 원형강관기둥에 관한 실험적 연구 (An Experimental Study on the Concrete Filled Circular Steel Columns with D/t)

  • 한병찬;임경택;엄철환;연길환;윤석천;정수영
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1995년도 가을 학술발표회 논문집
    • /
    • pp.215-218
    • /
    • 1995
  • This paper presents an experimental study on the strength and deformation of concrete-filled circular steel short columns. Six specimens of concrete-filled circular short columns were tested under concentric compressive load. For comparsion, three specimens of circular steel short columns were also loaded to failure. The ultimate strength, ductility, and confinement mechanism of columns were compared. In the comparison, the effect of witch-thickness ratio and concrete compressive strength on the behavior of colimns were examed. As a result, the axial load verse axial average strain relationship of concrete-filled circular steel columns was very stable, because of interactions between the concrete and steel, the strength are 13% and 30% larger than the strength extimated by simply superimposed method of the concrete and steel. The ratio of the circumferential to longitudinal strain increment, both measured on the steel suface, was 0.28 up to the longitudinal strain of 0.1%, increases from 0.3 to 0.8 between the strain of 0.1% to 0.3%, and 0.8 beyond the strain of 0.3%

  • PDF

밀폐형 동회전 2축 스크류의 제작에 관한 연구 (A Study on Machining of the Self-Wiping Co-Rotating Twin Screw)

  • 최부희;이상혁;최상훈
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.1426-1429
    • /
    • 2003
  • This paper describes screw tool design and machining method witch is able to design tool profile and 3-dimensional geometry for screws in self-wiping co-rotating twin screw extruder. The geometric features of screws for co-rotating twin screw extruders are developed from kinematic principles. Closely self-wiping screw segments are manufactured in universal milling machine by using designed screw tools. It is shown that experimental results verified the closely intermeshing condition in twin screw.

  • PDF

금속의 두께를 고려한 나선형 인덕터의 집중형 등가 회로의 제안 (A new lumped equivalent circuits for spiral inductor with metal thickness)

  • 오데레사;김흥수
    • 전자공학회논문지D
    • /
    • 제34D권9호
    • /
    • pp.21-27
    • /
    • 1997
  • Square spiral inductors are designed with EM program in accordance with the inner diameter and the metal thickness which is 0.2.mu.m and 20.mu.m respectively. We propose a parameter extraction method based on the S-parameter. Lumped equivalent circuits of spiral inductors are analyed with reflection coefficient S$_{11}$, of witch freqency rnage is 1~10GHz. When metal thickness is 0.2.mu.m, S$_{11}$ with EM simulation is not the same as S$_{11}$ that of SPICE simulation. So we suggests a new lumped equivalent circuits which compensate circuits. Te new lumped equivalent circuits are adequate for other inductor with small scale at high frequencies.ncies.

  • PDF

2행정 디젤기관의 소기압력이 성능특성에 미치는 영향 (The Effect of Scavenging pressure on Performance Characteristics in Two-Stroke Diesel Engine)

  • 김기복
    • 한국산업융합학회 논문집
    • /
    • 제21권2호
    • /
    • pp.45-51
    • /
    • 2018
  • Compression ignition diesel engine can reduce carbon emission than gasoline engine in case of high efficiency, output and durability. So, compression ignition diesel engine is used in various fields such as automobiles, industries and so on. Due to reducing of emission exhaust by Developing of injection and combustion type of diesel engine, emission of pollution substance is developed compared the past. Moreover, its efficiency and reduce of carbon emission is better than gasoline engine and it is used in power source of industries, transports and others because of its high efficiency and durability nowadays. In this study, we experiment by making and designing of compression ignition diesel engine witch has air-cooling, 2 cylinder and 2 strokes.

극간절연회복성능 향상을 위한 초고압GCB의 노즐형상설계 (Design of Nozzle Shape for UHV GCB to Improve the Dielectric Recovery Characteristics between Electrodes)

  • 송기동;박경엽;신영준;권기영;송원표
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
    • /
    • pp.479-481
    • /
    • 1995
  • This paper presents a method witch tan improve the dielectric recovery characteristics of UHV class gas circuit breakers by changing the nozzle shape. To calculate the dielectric recovery voltage between electrodes, the flow field and electric field analysis in a 362kV model interrupter has been performed with the commercial programs, RAMPANT and FLUX2D, respectively. As a result, we found that the nozzle shape affects the characteristics of dielectric recovery between electrodes and obtained great improvement of it by the changing the downstream nozzle shape.

  • PDF