• Title/Summary/Keyword: root point

Search Result 633, Processing Time 0.032 seconds

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

  • Kim, Tai Wook
    • Journal of Korean Society of Forest Science
    • /
    • v.4 no.1
    • /
    • pp.33-38
    • /
    • 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.

  • PDF

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

  • Bae, Jae-Sung;Shin, Won-Ho;Lee, In;Shin, Young-Sug
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.30 no.7
    • /
    • pp.29-35
    • /
    • 2002
  • Aeroelastic characteristics of a deployable missile control fin have been investigated. A deployable missile control fin is modeled by a 2-dimensional typical section. Supersonic Doublet-Point method is used for the computation of supersonic unsteady aerodynamic forces and Karpel's Minimum-State approximation is used for the aerodynamic approximation. Root-locus method and time-integration method are used for the linear and nonlinear flutter analyses. For the nonlinear flutter analysis the deployable hinge is represented by a asymmetric bilinear spring and is linearized by using the describing function method. From the flutter analyses, the effects of nonlinear parameters on the aeroelastic characteristics are investigated.

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

  • Solaiman, A.R.M.;Molla, M.N.;Hossain, M.D.
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.51 no.6
    • /
    • pp.527-533
    • /
    • 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.

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

  • Lee, Sun-Hyung;Choi, Soo-Young
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.34 no.4
    • /
    • pp.780-790
    • /
    • 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.

  • PDF

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
    • /
    • v.15 no.3
    • /
    • pp.181-187
    • /
    • 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
    • /
    • v.2 no.1
    • /
    • pp.35-42
    • /
    • 1959
  • The cuttings and apical portion of stein in sweet potato were growlh under artificial light and specific photoperied and temperature. Though the plant growth was poor under insufficient light intensity of artificial light, the tuber formations were induced at long light period (16L+8D) and not induced at short light period (8L+16D) and low temperature of darkparied. The determinative factor for tuber formation of sweet potato seems to be a stimulation which has intimate relationship with specific photoperiod and temperature and no direct relation with the growth of plant body and light intensity. The root pattern of inductive state for tubers and non-inductive state were different distinctly, the former were silky and slender, the latter were branchy, and stout appearence. This different root pattern must be due also to the specific photoperiod and temperature and may have any relationship with the stimulation for tuber formation from the point of auxin physiology etc.

  • PDF

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

  • Jun, Sung-Hee
    • Korean Journal of Digital Imaging in Medicine
    • /
    • v.13 no.2
    • /
    • pp.91-97
    • /
    • 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%).

  • PDF

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

  • Choi, Woo-Jung;Kwak, Jin-Hyeob;Jung, Jae-Woon;Yoon, Kwang-Sik;Chang, Nam-Ik;Huh, Yu-Jeong
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.49 no.1
    • /
    • pp.89-97
    • /
    • 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.

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

  • Kim, Cheol-Jim;Kim, Kwan-Su;Paek, In-Su
    • Journal of the Korean Solar Energy Society
    • /
    • v.38 no.2
    • /
    • pp.1-13
    • /
    • 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
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.49 no.2
    • /
    • pp.100-104
    • /
    • 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.