• 식물조직배양학회지
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• 제24권5호
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• pp.273-277
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• 1997

Rhizoctonia solani 추출물(elicitor)을 Hyoscyamus muticus 모상근배양에 처리하였을 때 sesquiterpene cyclase (SC)가 유도됨과 동시에 sesquiterpene화합물이 합성되어 배양액속에 축적하는 것으로 나타났다. 24시간 배양기간 동안 배양액으로부터 sesquiterpene을 추출ㆍ분리하여 배양할 경우, 추출ㆍ분리하지 않은 모상근배양보다 거의 두배의 함량이 생성되었다. Cyclase monoclonal antibody을 이용하여 immunoblot을 시도한 결과, 추출한 모상근배양과 추출하지 많은 모상근배양에서의 SC 절대량은 동일한 것으로 나타났으며, 효소활성도 현저한 차이가 없는 것으로 측정되었다. 이러한 결과는 terpenoid pathway에서 sesquiterpene 생합성이 이용가능한 기질의 량에 의해 조절되는 것으로 사료되며, feedback 조절은 sesquiterpene cyclase 효소에 앞서 일어나는 것으로 추정된다.

• 식물조직배양학회지
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• 제24권5호
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• pp.279-284
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• 1997

Hyoscyamus muticus의 phytoalexin으로 알려진 solavetivone, lubimin, rishitin 생합성에 결정적 역할을 담당하는 isoprenoid pathway의 첫 분지효소인 vetispiradiene synthase의 유도특성과 solavetivone, lubimin phytoalexin 생합성과의 관련성을 구명하기 위하여 H. muticus 현탁세포배양 및 모상근배양에 Rhizoctonia solani 추출액을 elicitor로 처리하였다. Elicitor을 처리하지 않은 현탁세포 및 모상근배양에서는 효소활성, 효소단백질 및 solavetivone, lubimin등이 전혀 검출되지 않았으나, elicitor을 처리한 세포에서는 효소활성이 급속히 유도되어 처리 12시간 후에 최고의 활성을 보였으며 그 후 점점 감소하였다. 효소활성의 정도는 면역반응을 이용하여 측정한 효소 단백질의 함량과 밀접한 상관관계를 보였으며, phytoalexin 총 함량은 모상근배양에서 2배이상 높았다. 특히 solavetivone 및 lubimin 생합성은 현탁 및 모상근배양에서 서로 다른 특이성을 보였는데, 현탁배양에서는 lubimin을, 모상근배양에서는 solavetivone을 선택적으로 다량 생산하였다.

• 비파괴검사학회지
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• 제29권6호
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• pp.525-533
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• 2009

Emphasis in the paper is placed on describing guided wave successes and challenges for applications in aircraft and composite materials inspection. Guided wave imaging methods discussed includes line of sight, tomography, guided wave C-scan, phased array, and ultrasonic vibration methods. Applications outlined encircles lap splice, bonded repair patch, fuselage corrosion, water loaded structures, delamination, and ice detection and de-icing of various structures.

• 한국추진공학회지
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• 제4권2호
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• pp.12-20
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• 2000

The numerical analysis, including chemical reaction of an entire ramjet engine is studied to understand the ignition transient mechanism and the dynamic characteristics of the Integrated Rocket Ramjet System comprehensively. Details of how a subsonic combustion environment is established from the supersonic ram air after removal of the inlet port cover, are examined during the ignition transient. Various physical processes are investigated systemically, including ignition, flame propagation, flame dynamics, and vorticity evolution.

• Journal of Welding and Joining
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• 제26권2호
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• pp.62-68
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• 2008

Effects of gravitational orientation on gas tungsten arc welding (GTAW) for 304 stainless steel were studied to determine the critical factors for weld pool formation, such as weld surface deformation and weld pool shape. This study was accomplished through an analytical study of weld pool stability as a function of primary welding parameters (arc current and arc holding time), material properties (surface tension and density), and melting efficiency (cross-sectional area). The stability of weld pool shape and weld surface deformation was confirmed experimentally by changing the welding position. The arc current and translational velocity were the major factors in determining the weld pool stability as a function of the gravitational orientation. A 200A spot GTAW showed a significant variation of the weld pool formation as the arc held longer than 3 seconds, however the weld pool shape and surface morphology for a 165A spot GTAW were 'stable', i.e., constant regardless of the gravitational orientation. The cross-sectional area of the weld (CSA) was one of the critical factors in determining the weld pool stability. The measured CSA ($13.5mm^2$) for the 200A spot GTAW showed a good agreement with the calculated CSA ($14.9mm^2$).

• 대한인간공학회지
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• 제15권2호
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• pp.165-176
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• 1996

Hand posture and force, which define aspects of the way an object is grasped, are features of robotic manipulation. A means for specifying these grasping "flavors" has been developed that uses an instrumented glove equipped with joint and force sensors. The new grasp specification system is being used at the Pennsylvania State University (Penn State) in a Virtual Reality based Point-and-Direct (VR-PAD) robotics implementation. In the Computer Integrated Manufacturing (CIM) Laboratory at Penn State, hand posture and force data were collected for manipulating bricks and other items that require varying amounts of force at multiple pressure points. The feasibility of measuring desired grasp characteristics was demonstrated for a modified Cyberglove impregnated with FSR (Force Sensitive Resistor) pressure sensors in the fingertips. A joint/force model relating the parameters of finger articulation and pressure to various lifting tasks was validated for the instrumented "wired" glove. Operators using such a modified glove may ultimately be able to configure robot grasping tasks in environments involving hazardous waste remediation, flexible manufactruing, space operations and other flexible robotics applications. In each case, the VR-PAD approach improved the computational and delay problems of real-time multiple- degree-of-freedom force feedback telemanipulation.

• 환경영향평가
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• 제4권2호
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• pp.39-57
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• 1995

이 논문은 미국 Pennsylvania의 델라웨어강 유역에서의 토지이용으로 인한 영향을 평가하기 위하여 수질모형 SWAT (Soil and Water Assessment Tool)를 GIS등과 결합하여 (Arc/info 와 GRASS)사용하였다. 이 논문에서는 GIS를 수치수질모형과 결합하여 사용하였으며 그 대상지역은 $250km^2$의 Brodhead Creek 유역이다. 수질모형에 사용된 자료는 1:250,000의 DEM (Digital Elevation Model)에서 추출된 자료와 토양자료 및 관측된 유량 및 질산염 농도와 관련된 자료이다. 그리고 DEM자료, Curve Number 및 기타 입력변수의 민감도를 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.495-496
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• 1998

The measurement of the amplitude and phase of electric fields on high voltage transmission lines is important for several reasons including a) Metering and determination of power flow, b) protective relaying. and c) fault sensing. The work reported here is directed toward a major improvement to optically based, electric-field sensors. This is a signal processing based technique for overcoming the instabilities of conventional, optically-based, electric-field sensors to changes in optical power or temperature.

• Applied Biological Chemistry
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• 제25권2호
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• pp.83-92
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• 1982

균일(均一)하게 환표식(環標識)된 $^{14}C-butachlor$를 2종(二種)의 한국토양중에서 3개월간(三個月間) 혐기적으로 배양시 생성된 $^{14}CO_2$와 휘발성 물질의 량(量)은 근소하였다. 토양A에서는 고압살균한 경우와 살균하지 않은 경우 처리된 방사능의 77.52%와 45.36%가 각각 MeOH로 추출되었고 나머지는 토양중에 흡착되었다. 반면 토양B에서는 58.85%와 37.23%가 각각 추출되었고 나머지는 토양중에 잔류하였다. $^{14}C-butachlor$의 흡착은 토양의 특성에 좌우되었다. 또한 GLC-MS에 의하여 2,6-diethyl-N-(butoxymethyl)-acetanilide가 주된 대사산물로 밝혀졌고 2,6-diethyl aniline과 2,6-diethyl acetanilide는 소량 생성되었다.

• 한국토양비료학회지
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• 제48권1호
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• pp.1-7
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• 2015

Global population is expected to reach nine billion in 2050 and the total demand for food is expected to increase approximately by 60 percent by 2050 as compared to 2005. Therefore, it is important to increase crop production in order to meet the global demand for food. Slow release fertilizers have been developed and designed in order to improve the efficiency of fertilizers. Mineral-based slow release fertilizers are useful because the minerals have a crystalline structure and are environmentally friendly in a soil. This review focuses on slow release fertilizers based on montmorillonite, zeolite, and layered double hydroxide phases as a host for nutrients, especially N. Urea was successfully stabilized in the interlayer space of montmorillonite by the formation of urea-Mg or Ca complex, $[(Urea)_6Mg\;or\;Ca]^{2+}$ protecting its rapid degradation in soils. Naturally occurring zeolites occluded with ammonium nitrate and potassium nitrate by molten salt treatment could be used as slow release fertilizer because the occlusion process increased the capacity of zeolites to store nutrients in addition to exchangeable cations. Additionally, surface-modified zeolites could also be used as slow release fertilizer because the modified surface showed high affinity for anionic nutrients such as nitrate and phosphate. Moreover, there were attempts to develop and use synthetic layered double hydroxide as a carrier of nitrate because it has positively charged layers which electrostatically bond nitrate anions. Kaolin was also tested by combining with a polymer or through the mechanical-chemical process for slow release of nutrients.