• Title/Summary/Keyword: 접선

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Comparative Anatomy of the Secondary Xylem in the stem of Araliaceous Plants in Korea (한국산 두릅나무과 식물 줄기에서 2기목부의 비교 해부)

  • 박동옥
    • Journal of Plant Biology
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    • v.36 no.4
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    • pp.345-355
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    • 1993
  • Anatomical study of the secondary xylem in Araliaceous plants, induding 7 genera and 11 species grown in Korea, was carried out to elucidate the relationship among genera in the family. Wood of Hedera has difbse porous and shows ulmiform pattern of angular vessels, simple perforation plate, and alternate pitting. In addition, its ray is homogeneous type II with only procumbent ray cell. Ring porous wood of Dendropanax shows ulmiform of angular vessels, simple perforation plate, alternate pitting, and heterogeneous type II ray, which has sometimes horizontal secretory cavity. Fatsia has diffuse porous wood, which shows ulmiform of angular vessels, scalariform perforation plate (3-9 bars), scalariform pitting, spiral thickening in the lateral wall of vessel, and heterogeneous type II ray with sheath cells. Kalopanax has ring porous wood, which shows ulmiform of circular vessels, simple perforation plate and alternate pitting, and heterogeneous type II ray. While K pictum appears tylose with septum, K pictum var. maximowczii appears tylose without septum. Echinopanax shows ring porous wood, ulmiform of angular vessels, simple perforation plate, scalariform pitting, and tylose with septum. And the ray of Echinopanax is paedomorphic type I composed of only upright cells. Acanthopanax genus is composed of diffuse porous wood, ulmiform of angular vessels, simple perforation plate and alternate pitting. In this genus, A. sessiliflorus has heterogeneous type II ray, apotracheal axial parenchyma and tylose with septum. A. senticosus appears paedomorphic type I with only upright cells, and tylose with septum. A. koreanum and A. sieboldianum have heterogeneous type II ray but have not tylose. Aralia is composed of ring porous wood, ulmiform of circular vessels, simple perforation plate, alternate pitting, heterogeneous type II ray, and tylose contained both septum and reticulate. On the basis of arrangement, shape, length and diameter of vessel element, the angle of end wall to vessel axis, and ray type, the line of specialization in these genera is as follow: from Fatsia, the most primitive, to the most highly specialized Aralia, throughout Hedera, Acanthopanax, Echinopanax, Dendropanax, and Kalopanax by turns. turns.

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Radial Variation of Anatomical Characteristics of Chestnut Wood (Castanea crenata) Grown in Korea - Vessel Element and Ray - (국내산 밤나무 목재의 해부학적 특성의 방사방향 변이성 - 도관요소 및 방사조직 -)

  • Lee, Seon-Hwa;Kwon, Sung-Min;Lee, Sung-Jae;Lee, Uk;Kim, Mahn-Jo;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.1
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    • pp.19-28
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    • 2009
  • Some wood anatomical characteristics of seven chestnut cultivars (Tanzawa, Ibuki, Arima, Ginyose, Tsukuba, Riheiguri, and Mansung) grown in Korea were examined in this study. We investigated the radial variation of wood components such as diameter and number of earlywood vessel element and ray density in cross section and number and height of ray in tangential section. Discs were taken from the stem of seven chestnut cultivars at breath height and cut into the radial strip. Cross, radial, and tangential sections, 10 to $20{\mu}m$ thick, were sliced with a sliding microtome. These sections were stained, dehydrated, and mounted with Canada balsam according to common procedure. Measurement and observation were performed with a light microscopy. In all chestnut cultivars, radial and tangential diameter of vessel element increased but number of vessel element per $mm^2$ decreased with increasing tree age. Ray spacing (per mm) in cross section from pith to bark showed no significant variation, while number of ray per $mm^2$ increased but ray height decreased with the increase of tree age. Conclusively, the results obtained in present study were thought to be some valuable information for separating juvenile and adult wood as well as identifying chestnut cultivars.

Study on the Estimation of Duncan & Chang Model Parameters-initial Tangent Modulus and Ultimate Deviator Stress for Compacted Weathered Soil (다짐 풍화토의 Duncan & Chang 모델 매개변수-초기접선계수와 극한축차응력 산정에 관한 연구)

  • Yoo, Kunsun
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.47-58
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    • 2018
  • Duncan & Chang(1970) proposed the Duncan-Chang model that a linear relation of transformed stress-strain plots was reconstituted from a nonlinear relation of stress-strain curve of triaxial compression test using hyperbolic theory so as to estimate an initial tangent modulus and ultimate deviator stress for the soil specimen. Although the transformed stress-strain plots show a linear relationship theoretically, they actually show a nonlinearity at both low and high values of strain of the test. This phenomenon indicates that the stress-strain curve is not a complete form of a hyperbola. So, if linear regression analyses for the transformed stress-strain plot are performed over a full range of strain of a test, error in the estimation of their linear equations is unavoidable depending on ranges of strain with non-linearity. In order to reduce such an error, a modified regression analysis method is proposed in this study, in which linear regression analyses for transformed stress-strain plots are performed over the entire range of strain except the range the non-linearity is shown around starting and ending of the test, and then the initial tangent modulus and ultimate deviator stresses are calculated. Isotropically consolidated-drained triaxial compression tests were performed on compacted weathered soil with a modified Proctor density to obtain their model parameters. The modified regression analyses for transformed stress-strain plots were performed and analyzed results are compared with results estimated by 2 points method (Duncan et al., 1980). As a result of analyses, initial tangent moduli are about 4.0% higher and ultimate deviator stresses are about 2.9% lower than those values estimated by Duncan's 2 points method.

Evaluation of Tangential Fields Technique Using TOMO Direct Radiation Therapy after Breast Partial Mastectomy (유방 부분 절제술 후 방사선 치료 시 TOMO Direct를 이용한 접선 조사의 선량적 유용성에 관한 고찰)

  • Kim, Mi-Jung;Kim, Joo-Ho;Kim, Hun-Kyum;Cho, Kang-Chul;Chun, Byeong-Chul;Cho, Jeong-Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.23 no.1
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    • pp.59-66
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    • 2011
  • Purpose: Investigation of the clinical use of tangential fields technique using TOMO direct in comparison to conventional LINAC based radiation therapy after breast partial mastectomy. Materials and Methods: Treatment plans were created for 3 left-sided breast cancer patients who had radiation therapy after breast partial mastectomy by using wedged tangential fields technique, field in field technique (FIF), TOMO Direct, TOMO Direct intensity modulated radiation therapy (IMRT) under the normalized prescription condition ($D_{90%}$: 50.4 Gy/28 fx within CTV). Dose volume histogram (DVH) and isodose curve were used to evaluate the dose to the clinical target volume (CTV), organ at risk (OAR). We compared and analyzed dosimetric parameters of CTV and OAR. Dosimetric parameters of CTV are $D_{99}$, $D_{95}$, Dose homogeneity index (DHI: $D_{10}/D_{90}$) and $V_{105}$, $V_{110}$. And dosimetric parameters of OAR are $V_{10}$, $V_{20}$, $V_{30}$, $V_{40}$ of the heart and $V_{10}$, $V_{20}$, $V_{30}$ of left lung. Results: Dosimetric results of CTV, the average value of $D_{99}$, $D_{95}$ were $47.7{\pm}1.1Gy$, $49.4{\pm}0.1Gy$ from wedged tangential fields technique (W) and FIF (F) were $47.1{\pm}0.6Gy$, $49.2{\pm}0.4Gy$. And it was $49.2{\pm}0.4$ vs. $48.6{\pm}0.8Gy$, $49.9{\pm}0.4$ vs. $49.5{\pm}0.3Gy$ Gy for the TOMO Direct (D) and TOMO Direct IMRT (I). The average value of dose homogeneity index was W: $1.1{\pm}0.02$, F: $1.07{\pm}0.02$, D: $1.03{\pm}0.001$, I: $1.05{\pm}0.02$. When we compared the average value of $V_{105}$, $V_{110}$ using each technique, it was the highest as $34.6{\pm}9.3%$, $7.5{\pm}7.9%$ for wedged tangential fields technique and the value dropped for FIF as $16.5{\pm}14.8%$, $2.1{\pm}3.5%$, TOMO direct IMRT as $7.5{\pm}8.3%$, $0.1{\pm}0.1%$ and the TOMO direct showed the lowest values for both as 0%. Dosimetric results of OAR was no significant difference among each technique. Conclusion: TOMO direct provides improved target dose homogeneity over wedged tangential field technique. It is no increase the amount of normal tissue volumes receiving low doses, as oppose to IMRT or Helical TOMO IMRT. Also, it simply performs treatment plan procedure than FIF. TOMO Direct is a clinical useful technique for breast cancer patients after partial mastectomy.

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The Irradiated Lung Volume in Tangential Fields for the Treatment of a Breast (유방암의 접선 조사시 피폭 폐용적)

  • Oh Young Taek;Kim Juree;Kang Haejin;Sohn Jeong Hye;Kang Seung Hee;Chun Mison
    • Radiation Oncology Journal
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    • v.15 no.2
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    • pp.137-143
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    • 1997
  • Purpose : Radiation pneumonitis is one of the complications caused by radiation therapy that includes a Portion of the lung tissue. The severity of radiation induced pulmonary dysfunction depends on the irradiated lung volume, total dose, dose rate and underlying Pulmonary function. It also depends on whether chemotherapy is done or not. The irradiated lung volume is the most important factor to predict the pulmonary dysfunction in breast cancer Patients following radiation therapy. There are some data that show the irradiated lung volume measured from CT scans as a part of treatment Planning with the tangential beams. But such data have not been reported in Korea. We planned to evaluate the irradiated lung volume quantitatively using CT scans for the breast tangential field and search for useful factors that could Predict the irradiated lung volume Materials and Methods : The lung volume was measured for 25 patients with breast cancer irradiated with tangential field from Jan.1995 to Aug.1996. Parameters that can predict the irradiated lung volume included; (1) the peruendicular distance from the Posterior tangential edge to the posterior part of the anterior chest wall at the center of the field (CLD) ; (2) the maximum perpendicular distance from the posterior tangential field edge to the posterior Part of the anterior chest wall (MLD) ; (3) the greatest perpendicular distance from the Posterior tangential edge to the posterior part of anterior chest wall on CT image at the center of the longitudinal field (GPD) ; (4) the length of the longitudinal field (L). The irradiated lung volume(RV), the entire both lung volume(EV) and the ipsilateral lung volume(IV) were measured using dose volume histogram. The relationship between the irradiated lung volume and predictors was evaluated by regression analysis. Results :The RV is 61-279cc (mean 170cc), the RV/EV is $2.9-13.0\%\;(mean\;5.8\%)$ and the RV/IV is $4.9-29.0\%\;(mean\;12.2\%)$. The CLD, the MLD and the GPD ave 1.9-3.3cm, 1.9-3.3cm and 1.4-3.1cm respectively. The significant relations between the irradiated lung volume such as RV. RV/EV, RV/IV and parameters such as CLD, MLD, GPO, L. $CLD\timesL,\;MLD\timesL\;and\;GPD\timesL$ are not found with little variances in parameters. The RV/IV of the left breast irradiation is significantly larger than that of the right but the RV/EVS do not show the differences. There is no symptomatic radiation pneumonitis at least during 6 months follow up. Conclusion : The significant relationship between the irradiated lung volume and predictors is not found with little variation on parameters. The irradiated lung volume in the tangential held is liss than $10\%$ of entire lung volume when CLO is less than 3cm. The RV/IV of the left tangential field is larger than that of the right but there was no significant differences in RV/EVS. Symptomatic radiation pneumonitis has not occurred during minimum 6 months follow up.

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