• 제목/요약/키워드: root point

검색결과 632건 처리시간 0.026초

천연경신(天然更新)의 요건(要件)으로서의 리기다소나무 곰솔 및 회양목의 내음성(耐陰性)의 조사(調査) (Investigation on the shade tolerance of Pinus rigida, P. Thunbergii and Buxus Koreana)

  • 김태욱
    • 한국산림과학회지
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    • 제4권1호
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    • pp.33-38
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    • 1965
  • It has already been noted that some tree species, denoted as tolerant species, endure to behavior shadiness in growth than those species, denoted as intolerant species, since this fact of tolerance must be involved in silvicultural practice, the present author, with pinus rigida, pinus Thunbergii, and Buxus koreana, investigated the relation of degree of shadiness to soil moisture condition. Because tolerant and intolerant trees must be considered from the standpoint of their ability to use any of the factors that are likely to be at low concentration in the dense or open forest. The observed results may be summarized as follows : 1. The ability of tolerance of the species to shadiness is differently concluded by the base with which the analysis was made, i.c. Height, growth, diameter growth, T-R ratio or dry matter increase and so on. Regarding this point root collar increment or dry matter increase were considered more reasonable bases for discussing the tolerability. 2. When total length growth, including both stem and root, is taken as standard for the comparison of the ability of tolerance for each species, higher soil moisture condition and thicker shadeniss lessened the ability of pinus rigida, seedlings. Pinus Thunbergii, showed. However more moisture resistant than pinus rigida. Buxus koreana, seemed to have stronger ability of tolerance than any others. 3. When total dry matter content taken as standard, the results obtained are given in Fig, 3. In pinus rigida, the soil moisture supplemented the lack of light.

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이선형 비선형성을 포함하는 접는 미사일 조종날개의 공탄성 해석 (Aeroelastic Analysis of Deployable Missile Control Fin with Bilinear Nonlinearity)

  • 배재성;신원호;이인;신영석
    • 한국항공우주학회지
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    • 제30권7호
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    • pp.29-35
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    • 2002
  • 접는 미사일 조종날개의 공력탄성학적 특성을 조사하였다. 접는 미사일 조종날개는 2차원 익형 모델로 가정하였다. 초음속 DPM을 이용하여 초음속 비정상 공기력을 계산하였으며, 최소 상태 변수 근사법을 이용하여 비정상 공기력을 근사화하였다. 선형 및 비선형 플러터 해석을 위해 근궤적법과 시간적분법을 사용하였다. 비선형 플러터 해석을 위해 전개부의 힌지는 비대칭 이선형 스프링으로 가정하였으며, 기술함수를 이용하여 선형화하였다. 플러터 해석으로부터, 비선형 파라미터가 공력탄성학적 특성에 미치는 영향을 조사하였다.

Response of Chickpea to Dual Inoculation with Rhizobium and Arbuscular Mycorrhiza, Nitrogen and Phosphorus

  • Solaiman, A.R.M.;Molla, M.N.;Hossain, M.D.
    • 한국작물학회지
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    • 제51권6호
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    • pp.527-533
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    • 2006
  • The response of chickpea (Cicer arietinum L.) to dual inoculation with Rhizobium (R) and arbuscular mycorrhiza (AM), nitrogen (N) and phosphorus (P) was studied on spore abundance and colonization of AM, nodulation, growth, yield attributes and yield. In all the parameters of the crop the performance of Rhizobium inoculant alone was superior to control. Dual inoculation with Rhizobium and AM in presence of P performed the best in recording number of spore $100g^{-1}$ rhizosphere soil and root colonization, number and dry weight of nodule, dry weights of shoot and root, number of pod $plant^{-1}$, number of seed $pod^{-1}$, seed and stover yields of chickpea. The maximum seed yield of 3.33 g $plant^{-1}$ was obtained by inoculating chickpea plants with Rhizobium and AM in association with P. From the view point of nodulation, growth, yield attributes and yield of chickpea, dual inoculation with Rhizobium and AM along with P was considered to be the balanced combination of nutrients for achieving the highest output from cultivation of chickpea in Shallow Red Brown Terrace Soil of Bangladesh.

포스트가 치근내 응력분산에 미치는 영향에 관한 삼차원 유한요소법적 연구 (STRESS DISTRIBUTION OF ENDODONTICALLY TREATED TOOTH ACCORDING TO THE POST -THREE-DIMENSIONAL FINITE ELEMENT STUDY-)

  • 이선형;최수영
    • 대한치과보철학회지
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    • 제34권4호
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    • pp.780-790
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    • 1996
  • The endodontically treated tooth is generally restored with post and core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the stress distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisor had extensively damaged. After the root canal therapy it was post cored, and restored with PFG crown. The three-dimensional model, in which the root was supported with a normal alveolar bone, was constructed. Force was applied to the centric stop point with the angle of 135 degrees to the long axis of the tooth. Force was assumed to be 250N as functional maximum bite force of upper central incisors. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin and the apical portion of the dentin. 2. Stress in the post was more concentrated on the post apex. 3. The displacement of the post at the post-cement interface was almost symmetrical la-bio-lingually. 4. It assumed that restoring extensively damaged tooth with a post-core and PFG crown is an adequate method of restoration.

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Oxidation of extracellular cysteines by mercury chloride reduces TRPV1 activity in rat dorsal root ganglion neurons

  • Jin, Yun-Ju;Park, Jin-Young;Kim, Jun;Kwak, Ji-Yeon
    • Animal cells and systems
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    • 제15권3호
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    • pp.181-187
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    • 2011
  • Transient receptor potential vanilloid type 1 (TRPV1) receptor plays an important role as a molecular detector of noxious signals in primary sensory neurons. Activity of TRPV1 can be modulated by the change in the environment such as redox state and extracellular cations. In the present study, we investigated the effect of the mercury chloride ($HgCl_2$) on the activity of TRPV1 in rat dorsal root ganglia (DRG) neurons using whole-cell patch clamp technique. Extracellular $HgCl_2$ reversibly reduced the magnitudes of capsaicin-activated currents ($I_{cap}$) in DRG neurons in a dose-dependent manner. The blocking effect of $HgCl_2$ was prevented by pretreatment with the reducing agent dithiothreitol (DTT). Inhibition of $I_{cap}$ by $HgCl_2$ was abolished by point mutation of individual cysteine residues located on the extracellular surface of TRPV1. These results suggest that three extracellular cysteines of TRPV1, Cys616, Cys634 and Cys621, are responsible for the oxidative modulation of $I_{cap}$ by $HgCl_2$.

STUDIES ON THE PHYSIOLOGY OF DEVELOPMENT IN CROPS. 4. STUDIES ON PHYTOPERIODICAL CONTROL FOR TUBER FORMATION IN SWEET POTATO

  • Kim, Yong-Choll
    • Journal of Plant Biology
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    • 제2권1호
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    • pp.35-42
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    • 1959
  • 1. 발아시부터 단일, 암기저온 조건하에서는 괴근은 전연 형성되지 않고, 장일조건에서만 괴근이 형성됨. 따라서 장일조건이 고구마괴근 형성에 대한 유도조건 내지 촉진조건임을 알 수 있다. 2. 본실험은 시종 약전광(300W 전구 사용)으로 재배하였기 때문에 동화작용이나 생장이 특히 미약한 상태에서도 괴근이 유도되었다. 따라서 괴근형성에는 동화물질이나 생장보다도 장일조건이 직접적결요인을 이루는 1종자극을 성립하는 것으로 보인다. 3. 장기조건과 단일조건하의 근계가 서로 특이한 상태를 나타냈고 그것은 단일과 장일조건이 이룬 자극과 관계하는 것으로 보인다. 4. 고구마괴근이 장일조건에 유되되는 사실의 생태학적 의의를 고찰함.

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근로자 구강검진 시 파노라마방사선사진의 필요성에 관한 고찰 (A Study of Usefulness of Panoramic Radiography in Case of Employees' Oral Examination)

  • 전성희
    • 대한디지털의료영상학회논문지
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    • 제13권2호
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    • pp.91-97
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    • 2011
  • This study was conducted to know usefulness of panoramic radiography by comparing clinical evaluation and dental panoramic radiography in case of oral examination. Following results were concluded by analyzing difference between the result of Clinical evaluation and dental panoramic radiography. According to comparison the result of clinical evaluation and panoramic radiography, In Shin's research, dental caries was higher by 23.1%, periodontal disease was 31.9%, in An's research, dental caries was 24.2%. From new point of view from panoramic radiography, impacted tooth was 33.6%, Sinus abnormalities was 11.6%, periapical lesion was 5.4% in Shin's research and periapical lesion was 17.4%, 3rd molar impaction was 15.3% and retained root was 5.3% in An's research. Any kind of caries were not found in oral examination in the 66.7% of patients among patients with dental root caries in An's research. There were misdiagnose in oral examination(even side(59.5%),proximal side(59.5%), seconds caries(44.0%).

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영산강.섬진강 유역을 대상으로 한 논 오염부하 산정 단순회귀모형 적용 (Application of Simple Regression Models for Pollutants Load Estimation of Paddy to Yeongsan and Seomjin River Watersheds)

  • 최우정;곽진협;정재운;윤광식;장남익;허유정
    • 한국농공학회논문집
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    • 제49권1호
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    • pp.89-97
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    • 2007
  • Simple regression models for pollutants load estimation of paddy developed by the Ministry of Environment in 1995 were tested with the data (T-N, T-P, $COD_{Mn}$, and SS) collected from Yeongsan and Seomjin river watersheds, and improvement measures were suggested. Overall, the simulated values showed a great difference from the measured values except for T-P according to the statistical analyses (RMSE, root mean square error; RMAE, root mean absolute error; RB, relative bias; EI, efficiency index). Such difference was assumed due to the fact that the models use only hydrologic factors (quantity factor) associated with precipitation and run-off as input parameters, but do not consider other factors which are likely to affect pollutant concentration (quality factor) including days after fertilization. In addition, in terms of accessibility of the models, some parameters in the models such as run-off depth and run-off amount which can not be obtained from the weather database but should be collected by on-site measurements need to be replaced with other variables.

풍력터빈 타워 하중 저감을 위한 타워 댐퍼 게인 스케줄링 알고리즘 설계 (Design of Tower Damper Gain Scheduling Algorithm for Wind Turbine Tower Load Reduction)

  • 김철진;김관수;백인수
    • 한국태양에너지학회 논문집
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    • 제38권2호
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    • pp.1-13
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    • 2018
  • This paper deals with the NREL (National Renewable Energy Laboratory) 5-MW reference wind turbine. The controller which include MPPT (Maximum power point tracking) control algorithm and tower load reduction control algorithm was designed by MATLAB Simulink. This paper propose a tower damper algorithm to improve the existing tower damper algorithm. To improve the existing tower damper algorithm, proposed tower damper algorithm were applied the thrust sensitivity scheduling and PI control method. The thrust sensitivity scheduling was calculated by thrust force formula which include thrust coefficient table. Power and Tower root moment DEL (Damage Equivalent Load) was set as a performance index to verify the load reduction algorithm. The simulation were performed 600 seconds under the wind conditions of the NTM (Normal Turbulence Model), TI (Turbulence Intensity)16% and 12~25m/s average wind speed. The effect of the proposed tower damper algorithm is confirmed through PSD (Power Spectral Density). The proposed tower damper algorithm reduces the fore-aft moment DEL of the tower up to 6% than the existing tower damper algorithm.

Photosynthetic Response of Korean Ginseng under Saline Condition

  • Cho, Jin-Woong;Kim, Choong-Soo
    • 한국작물학회지
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    • 제49권2호
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    • pp.100-104
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    • 2004
  • This study was conducted to investigate the effect of the salinity on growth, inorganic ion content, and photosynthetic rate ($\textrm{P}^{N}$) in Korean ginseng (Panax ginseng C.A. Meyer) with complex fertilizer (CF) and NaCl concentrations. The salinity was applied to plant using NaCl and CF, and controlled an EC as 0.0, 1.0, 2.0 and 3.0 dS $\textrm{m}^{-1}$. The salinity treated three times at 35, 42 and 49 d after transplanting. The leaf area in different electrical conductivity (EC) decreased only the higher NaCl 1.0 dS $\textrm{m}^{-1}$. The root growth increased with CF and especially, it was two times higher at 3.0 dS $\textrm{m}^{-1}$ than that of control. But the root growth sharply decreased with NaCl compared to CF. The light saturation point of Korean ginseng was around 100 $\mu\textrm{mol}\;\textrm{m}^{-2}\textrm{s}^{-1}$ photosynthetically active radiation (PAR), and $\textrm{P}^{N}$ increased as CF increased but decreased with NaCl especially at the late growth stage. The $\textrm{Na}^{+}$ content in Korean ginseng increased sharply with NaCl.