• 한국토양비료학회지
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• 제50권6호
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• pp.674-683
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• 2017

The frequency and intensity of soil moisture stress associated with climate change has increasing, and the stability of field crop cultivation has decreasing. This experiment was conducted to investigate the effect of soil moisture management method on growth and yield of corn. Soil moisture was managed at the grade of WSM (wet soil moisture, 34.0~42.9%), OSM (optimum soil moisture, 27.8~34.0%), DSM (dry soil moisture, 20.3~27.8%), and ESM (extreme dry moisture, 16.6~20.3%) during V8 (8th leaf stage)-VT (tasseling stage). After VT, irrigation was limited. The treated amount of irrigation was 54.1, 47.7, 44.0 and 34.5% of total water requirement, respectively. The potential evapotranspiration during the growing period was $3.29mm\;day^{-1}$, and upward movement of soil water was estimated by the AFKAE 0.5 model in the order of ESM, DSM, OSM, and WSM. We could confirm this phenomenon from actual observations. There was no significant difference in leaf characteristics, dry matter, and primary productivity depending on the level of soil moisture, but leaf development was delayed and dry weight decreased in DSM. However, dry weight and individual productivity of DSM increased after irrigation withdrawal compared to that of OSM. In DSM, ear yield and number of kernels per ear decreased, but water use efficiency and harvest index were higher than other treatments. Therefore, it is considered that the soil moisture is concentratedly managed before the V8 period, the V8-VT period is controlled within the range of 100 to 500 kPa (20.3~27.8%), and no additional irrigation is required after the VT.

• 한국작물학회지
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• 제29권3호
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• pp.267-274
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• 1984

질소의 추비가 소맥엽신의 기공개도에 어떠한 영향을 미치는가를 검토하기 위하여 소맥 조광 품종을 공시하여 질소추비와 무추비구로 처리하여 침윤법으로 최고분얼기, 절간신장기, 수잉기, 개화기, 등숙중기에 기공개도를 측정하였던바 그 결과는 다음과 같다. 1. 소맥엽신의 기공개도는 생육이 진전됨에 따라 증가하여 개화기경에 최대에 달하였으며 그 이후는 저하하였다. 2. 1 일중 기공개도가 최대로 되는 시각은 각시기 모두 정오경이었으며 오후 6시경에는 상당히 폐공 되었으나 이는 생육단계에 따라 다소 상이하였다. 3. 질소의 추비는 엽신의 기공개도를 증가시켰는데 그 정도는 생육이 왕성한 수잉기와 개화기에 특히 큰 경향이었다. 4. 상위엽은 하위엽에 비하여 모든 생육단계에서 큰 기공개도를 나타내었으며, 질소추비에 의한 기공개도의 차이도 상위엽이 하위엽에 비하여 크게 나타나는 경향이었다. 5. 엽신의 질소함량과 1 일중 기공개도의 최대치간에는 고도의 정상관(r=0.66＊＊) 관계가 있었는데, 상위엽과 하위엽 모두 같은 경향이었다. 6. 각 엽기의 엽위간 기공개도의 차는 완전 전개한 최상위엽이 최대치를 나타내었고 전개중인 미성숙엽이나 엽의 노화가 진전된 하위엽일수록 기공개도는 작았다. 7. 각 엽신의 함수중, 근중 및 근의 활력은 질소의 추비에 의하여 증가되었는데 이는 기공개도를 증대시친 한 요인으로 작용한 것으로 추찰되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.494-497
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• 2003

A rotating device driven by an Inchworm motor was designed and fabricated to be used as an angie standard system. 1. PZT was adopted as a driving source, while the movement of PZT was guided by the leaf spring employing the elastic transformation of metals. 2. The device could rotate in a 360-degree arc. continuously Performance test of the device showed about 0.02 sec. of the minimum revolution angle and 1/15 rpm of the maimum revolution speed. 3. To improve its performance requires further studies on realizing a shifting device with faster response time, on increasing the output current (capacity) of the power amplifier used to drive PZT, on the dynamic motion of clamping. and on determining the optimum clamping condition

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.272-273
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• 2013

Some living thingsuse micro- or nano- structures for living in nature. Scientists and engineers made efforts to mimic them, and they succeeded in making new types of applications. They used 'Namib desert beetle' to self-filling device by moisture harvesting and 'lotus leaf' to self-cleaning device by water repelling. 'Namib desert beetle' and lotus leaf have micro-patterns on their surface, which consists of hydrophobic or hydrophilic materials [1]. Moreover, micro-patterns on the surface make self-filling or self-cleaning property enhanced because of the surface roughness. Surface roughness enhances wettability [2]. Micro-pattern is a significant factor to make the surface be functional, so we want to make new types of functional surface by micro-patterning. In this work,we make several functional micro-patterns (radial, line, and dot arrays) using maskless lithography and analyze the characteristics of each micro-pattern. In order to analyze and understand surface characteristics, micro-patterns with varying sizes are investigated. All experiments are proceeded on mr-DWL5 photo resists coated on silicon wafers in same condition. All the experiments have demonstrated good performances about hydrophobic or hydrophilic property corresponding to their material and structural combinations. In radial micro-pattern, although the surface is flat, water drops on hydrophilic radial pattern can be convergent to a middle point and water drops on hydrophobic radial pattern can be divergent from the middle point. In line array micro-pattern, water drops can roll off along only one direction in parallel with the line arrays. Such phenomena might be mainly caused by the local change of surface roughness. From these results, controlling the movement and direction of water drops is made feasible without introducing a slope, which can potentially be used for new types of applications.

• Journal of Plant Biology
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• 제29권1호
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• pp.41-51
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• 1986

The plants of Nicotiana tabacum L. cv. NC2326 were germinated in 10 cm D$\times$20 cm H polyethylene pot, and sand-cultured with Hoagland solution near by the window of laboratory room(26$\pm$5$^{\circ}C$). The growing plants were sprayed with various concentrations of ABA around 9 : 00 a.m. once in every two days for 12 weeks in summer. As the results, frequency of stomatal number, stomatal opening, chlorophyll content, respiration rate, and protein content in the leaves were decreased with the increasing of concentrations of ABA, respectively. The plant growth was inhibited by exogenous ABA, but leaf abscission was not found during the experimental period. The ratio of three to one in chlorophyll a to b was not altered by exogenous ABA. All the stomata were closed within three minutes by 100 $\mu\textrm{g}$ ml-1 ABA and within seven minutes by 1-10 $\mu\textrm{g}$ ml-1 ABA after the spraying of ABA, and then reopended after a few hours in 1-10 $\mu\textrm{g}$ ml-1 ABA and after 24 hours in 100 $\mu\textrm{g}$ ml-1 ABA. The polar movement of chloroplast within the guard cells was found in the higher concentrations of 10 and 100 $\mu\textrm{g}$ ml-1 ABA, but not found in the lower concentrations than 1 $\mu\textrm{g}$ ml-1 ABA. During the night and weak light, it was fond that the inhibition of respiration rate by the higher concentration of ABA was owing to firstly the stomatal closure by the spraying of ABA and secondly the decrease of stomatal frequency by the inhibition of stomatal development with exogenous ABA for the long period of 12 weeks. In the band number of leaf protein by the electrophoresis, most of the protein bands were disappeared by the higher concentration of 100 $\mu\textrm{g}$ ml-1 ABA, but were not altered by the lower concentration of ABA in comparison with control.

• Smart Structures and Systems
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• 제7권1호
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• pp.1-13
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• 2011

It has been shown in the literature that active adjustment of the intake area of a jet engine has potential to improve its fuel efficiency. This paper presents the design and control of a novel proof-of-concept active jet engine intake using Nickel-Titanium (Ni-Ti or Nitinol) shape memory alloy (SMA) wire actuators. The Nitinol SMA material is used in this research due to its advantages of high power-to-weight ratio and electrical resistive actuation. The Nitinol SMA material can be fabricated into a variety of shapes, such as strips, foils, rods and wires. In this paper, SMA wires are used due to its ability to generate a large strain: up to 6% for repeated operations. The proposed proof-of-concept engine intake employs overlapping leaves in a concentric configuration. Each leaf is mounted on a supporting bar than can rotate. The supporting bars are actuated by an SMA wire actuator in a ring configuration. Electrical resistive heating is used to actuate the SMA wire actuator and rotate the supporting bars. To enable feedback control, a laser range sensor is used to detect the movement of a leaf and therefore the radius of the intake area. Due to the hysteresis, an inherent nonlinear phenomenon associated with SMAs, a nonlinear robust controller is used to control the SMA actuators. The control design uses the sliding-mode approach and can compensate the nonlinearities associated with the SMA actuator. A proof-of-concept model is fabricated and its feedback control experiments show that the intake area can be precisely controlled using the SMA wire actuator and has the ability to reduce the area up to 25%. The experiments demonstrate the feasibility of engine intake area control using an SMA wire actuator under the proposed design.

• 농약과학회지
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• 제7권4호
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• pp.302-309
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• 2003

신규 화합물 triazolyl quinoline 유도체 230여개의 벼 도열병, 벼 잎집무늬마름병, 토마토 잿빛곰팡이병, 토마토 역병, 밀 붉은녹병과 보리 흰가루병에 대하여 방제효과를 조사하고, 녹병과 흰가루병에 대하여 예방효과가 우수한 KSI-4315와 KSI-4317을 선발하여 밀 붉은녹병과 보리 흰가루병에 대한 작용 특성을 실험하였다. Triazolyl quinoline 유도체인 KSI-4315와 KSI-4317 두 화합물은 구조에서 탄소 4번 위치에 각각 MeS moiety와 MsO moiety를 가진 화합물이다. 두 화합물은 밀 붉은녹병과 보리 흰가루병에 대하여 우수한 예방효과와 치료효과를 나타냈다. KSI-4317은 보리 흰가루병에 대하여, KSI-4315 는 밀 붉은녹병에 대하여 더 높은 예방효과와 치료효과를 보였다. 또한 두 화합물은 지속성도 우수하였다. 밀 붉은녹병에 대하여는 두 약제가 유사하였으나, KSI-4317은 보리 흰가루병에 대하여 특히 약효 지속성이 뛰어나 약제처리 7일 후 에 접종하여도 90% 이상의 방제가를 보였다. 약제의 침투이행성을 엽육이행, 엽간이행과 뿌리로부터 지상 부로의 침투이행에 대하여 실험한 결과, 밀에서 KSI-4315와 KSI-4317은 거의 침투 이행하지 않았으나, 보리에서는 KSI-4315 보다 KSI-4317이 높은 침투이행성을 보였다. 이상의 결과로부터 KSI-4317은 포장에서 밀 붉은녹병과 보리 흰가루병을 효과적으로 방제하리라 생각된다.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.238-244
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• 2010

Rhizobia are well-known for their ability to infect and nodulate legume roots, forming a nitrogen-fixing symbiosis of agricultural importance. In addition, recent studies have shown that rhizobia can colonize roots and aerial plant tissues of rice as a model plant of the Graminaceae family. Here we show that rhizobia can invade tobacco, a model plant belonging to the Solanaceae family. Inoculation of seedling. roots with five GFP-tagged rhizobial species followed by microscopy and viable plating analyses indicated their colonization of the surface and interior of the whole vegetative plant. Blockage of ascending epiphytic migration by coating the hypocotyls with Vaseline showed that the endophytic rhizobia can exit the leaf interior through stomata and colonize the external phyllosphere habitat. These studies indicate rhizobia can colonize both below- and above-ground tissues of tobacco using a dynamic invasion process that involves both epiphytic and endophytic lifestyles.

• Applied Biological Chemistry
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• 제36권6호
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• pp.463-468
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• 1993

솔잎혹파리(Thecodiplosis japonensis Uchida et Inouye) 방제용으로 소나무의 수간에 주입된 침투성 살충제 phosphamidon(2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate)의 이행 및 분포를 구명하기 위하여 $[vinyl,\;carbonyl-^{14}C]phosphamidon$을 약 10년생의 적송과 해송에 각각 수간주사하였다. 이 약제의 최고이행속도는 적송(Pinus densiflora Sieb. et Zucc.)과 해송(Pinus thunbergii Parl.)에서 각각 약 10 cm/hr(7월)와 2 cm/hr(12월)이었다. 처리된 방사능은 하계의 적송에서는 75일까지 일정한 수준을 유지하였으나 동계의 해송에서는 150일까지 유지하였다. 본 약제가 살충가능한 농도로 top에 도달하는데 걸리는 기간은 적송(7월)에서는 3일 이내인 반면 해송(12월)에서는 15일 이내이었으며, 그 이행정도는 약제처리시기 및 수종에 의하여 영향을 받았다. 솔잎에 잔류하는 phosphamidon과 그 대사산물은 methanol로 잘 추출되었으며, 솔잎시료의 methanol 추출액을 autoradiography한 결과 phosphamidon은 소나무내에서 신속히 분해되어 7일 내에 약 80% 정도가 분해되었다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.248-251
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• 2002

The intensity modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation treatment of patients. Patient dose verification is clinically one of the most important parts in the treatment delivery of the radiation therapy. The three dimensional (3D) reconstruction of dose distribution delivered to the target helps to verify patient dose and to determine the physical characteristics of beams used in IMRT. A new method is presented for the pretreatment dosimetric verification of two dimensional distributions of photon intensity by means of Beam Intensity Scanner System (BISS) as a radiation detector with a custom-made software for dose calculation of fluorescence signals from scintillator. The scintillator is used to produce fluorescence from the irradiation of 6MV photons on a Varian Clinac 21EX. The BISS reproduces 3D- relative dose distribution from the digitized fluoroscopic signals obtained by digital video camera-based scintillator(DVCS) device in the IMRT. For the intensity modulated beams (IMBs), the calculations of absorbed dose are performed in absolute beam fluence profiles which are used for calculation of the patient dose distribution. The 3D-dose profiles of the IMBs with the BISS were demonstrated by relative measurements of photon beams and shown good agreement with radiographic film. The mechanical and dosimetric properties of the collimating of dynamic and/or step MLC system alter the generated intensity. This is mostly due to leaf transmission, leaf penumbra and geometry of leaves. The variations of output according to the multileaf opening during the irradiation need to be accounted for as well. These phenomena result in a fluence distribution that can be substantially different from the initial and calculative intensity modulation and therefore, should be taken into account by the treatment planning for accurate dose calculations delivered to the target volume in IMRT.