• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.115-126
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• 1989

This study was conducted to determine the time and methods of predicting tobacco yield, by studying the relationship of yield components to yield. 1. The relationship between each position in leaf dry weight and approached gradually each other and also correlation coefficient of top leaf was higher than that of lower leaf. The leaf dry weight per plant was highly correlated with leaf area from 16th leaf position on stalk. Leaf dry weight of each leaf position on stalk was highly correlated with leaf dry weight per plant at 14 to 16th leaf position. 2. The correlation coefficient between leaf dry weight and leaf area per plant was higher at the late growth stage than at the early growth stage, and higher between the near stages. Correlation coefficient between leaf dry weights was higher than that of leaf areas. 3. Flue-cured tobacco yield be estimated from leaf dry weight per plant at 50 to 55 days after transplanting. 4. Air-cured tobacco yield could be predicted from leaf dry weight per plant at 60 days after transplanting.

• The Journal of Korean Society for Radiation Therapy
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• v.13 no.1
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• pp.47-50
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• 2001

Purpose : 체내에서 optimal한 dose distribution을 얻기 위해 도입된 IMRT를 시행할 때 사용하는 MLC는 기계특성상 장기적인 check와 교정을 요한다. 또한 MLC는 static하지 않고 dynamic하기 때문에 leaf position의 실제 위치가 매우 중요하다. MLC QA를 위해 QA 소요시간 및 노력이 많이 MLC position check 요구되는 불편이 있어, 삼성서울 병원에서 필름을 이용한 MLC position check device를 제작하여 간편하게 사용하고 그 우수성에 대해 결과를 보고하고자 한다. Materials and Method : MLC position을 check하기위해 사각형 의 device(acryl:$40{\times}40{\times}5cm$)를 제작하였다. position check device의 정확도를 위해 표면에 real scale 표시용으로 Pb marker를 2cm 간격으로 부착하였다. MLC QA film은 마주보는 (opposite) MLC leaf의 간격이 4mm로 set up한 상태에서 double exposure하여 marker를 이용하여 오차를 분석하였다. MLC position check device의 효율성을 평가하기위해 6MV photon으로 10번 반복 실험을 실시하여 MLC leaf의 평균오차를 조사하고 조사에 걸린 시간을 비교하여 유용성을 평가하였다. Results : 실험결과 MLC leaf의 평균오차를 조사하고 조사에 걸린 시간을 비교하여 유용성을 평가하였다. 범위는 1.45mm였고, 최소 오차는 0.34mm로 나타났다. 1회 조사에 걸린 시간은 평균적으로 약 30분 정도 소요되었다. MLC position check device의 효율성을 평가한 결과오차의 반복성은 관찰되지 않았다. Conclusion : MLC leaf position의 정기적인 check와 교정을 위해 본원에서는 주1회 정기 position error를 check하고 있으며, 평균 월1회 교정을 한다. 본 실험을 통해 MLC position check device를 사용하여 leaf 오차가 2mm이하의 만족할 만한 결과를 얻었다. 또한 MLC position check device를 사용하면 짧은 시간에 모든 leaf의 position error를 쉽게 측정할 수 있고 한 장의 필름으로 모든 결과를 평가할 수 있어 경제성 및 업무의 효율성도 높일 수 있었다.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.1
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• pp.74-81
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• 1991

This study was conducted to find out physical and chemical characteristics of burley and flue-cured tobacco leaves followed by location, growing season and leaf position during the period 1985 to 1989. The locations of flue-cured tobacco were 7(65farms) and burley tobacco were 4(40 farms). 1. Flue-cured tobacco leaves The locations of Ch'unch'on and Suwon were higher nicotine and ether extract content, Taegu and Chinju were higher total nitrogen content but Chiniju was lower red color of cured leaves than that of other location. Nicotine content increased but total sugar content decreased during the period 1985 to 1989. Nicotine and total nitrogen content increased but crude ash decreased from lower leaf position to higher leaf position. Total sugar and ether extract content were variable followed by leaf position. 2. Burley tobacco leaves. The location of Ch'onju was higher ether extract content than that of others location, but there was no significant difference the others chemical component among location. Nicotine content and red color of cured leaves increased during the period 1985 to 1989. Nicotine, total nitrogen and ether extract content increased but decreased crude ash content and brightness of cured leaf from lower leaf position to higher leaf position.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.297-303
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• 2006

Cuticular waxes on tea (Camellia sinensis L.) loaves consisted mainly of alkanes, fatty acids, primary alcohols, triterpenes, and a group of unknown compounds, dominated by primary alcohols and triterpenes. Tea tree accessions used in this study were M-1, M-2, Sakimidori, and Yabukita. For all accessions, the alkane, fatty acid, and primary alcohol constituents consisted of a homologues series, and the major constituents of primary alcohol class were the C28 and C30 homologues. Triterpenes consisted of friedelin, $\beta-amyrin$, and three unidentified ones and friedelin was the most abundant. Leaf area and the total amounts of cuticular waxes per leaf increased with lower leaf position from the apical bud in Yabukita variety. With different leaf position, total wax amount per unit leaf area on the youngest leaves of P1 (the uppermost leaf position) showed the largest amount $(12.80{\mu}g/cm^2)$, and on mature loaves of P2 to P6 ranged from 7.08 to $7.77{\mu}g/cm^2$, and then on the oldest loaves of P7 (the lowest leaf position) remained at an increased level $(17.53{\mu}g/cm^2)$. During leaf development (lower leaf position), the amount of primary alcohols decreased from P1 to P6 and increased at P7, whereas that of triterpenes increased from P1 to P7. The percentage of each wax class in the total wax amount occurred a decrease in primary alcohol and an increase in triterpene, with leaf age.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.186-192
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• 2004

This study was carried out to analyze the organic acids, polyphenols, pigments and fiber materials concentration with a different stalk position and grade of korean leaf tobaccos. Eight kinds of flue-cured leaf tobaccos which were different stalk position and grade were used for this study. Three kinds of major organic acids(citric, malic and oxalic), 2 kinds of polyphenols(chlorogenic acid and rutin), 3 kinds of pigments($\beta$-carotene, chlorophyll-a and chlorophyll-b), and 2 kinds of fiber components(pectin and lignin) were analyzed. All of these chemical components were changed with a different stalk position. When the citric acid, malic acid, $\beta-carotene$, chlorophyll-a, and lignin concentration were low in the middle stalk position and high in both bottom and upper position, oxalic acid and chlorogenic acid show the highest concentration in the middle stalk position. All of these chemical components also changed with a different grade of leaf tobaccos. As the citric acid, malic acid, $\beta-carotene$, chlorophyll-b, and lignin concentration decreased as the grade ascended, the oxalic acid and chlorogenic acid concentration increased as the grade ascended. This results assumed that the quality of korean leaf tobacco was directly proportional to oxalic acid and chlorogenic acid concentration but it was inversely proportional to citric acid, malic acid, $\beta-carotene$, chlorophyll-b and lignin concentration.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.38-45
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• 2002

This study was conducted to determine the smoke component concentration and the smoke distribution in the cambridge filter pad and cigarette filter with stalk position and grade of Korean leaf tobaccos. 12 grades of flue-cured and burley leaf tobaccos which were taken from the Kim-cheon and Ock-cheon leaf tobacco processing factory were used for this study. Six kinds of smoke components such as tar, nicotine, water, carbon monoxide(CO), carbon dioxide($CO_2$) puff No. collected in the cambridge filter pad and cigarette filter were analyzed. Also, nicotine/tar, CO/tar ratio were calculated from the analytical data. Puff no., CO, and $CO_2$ concentration of flue-cured and burley tobacco leaves at high stalk position were higher than those of low stalk position, and these components were increased in high grade of leaf tobacco. Compared with flue-cured tobacco, burley tobacco showed a little values of puff no., nicotine, and tar concentration. The pH range of burley tobaccos was broader than that of flue-cured tobaccos, and the ammonia concentration of burley tobaccos was significantly higher than that of flue-cured tobaccos. The pH value and ammonia concentration of burley tobaccos were decreased as stalk position of leaf tobaccos decreased. The distribution of smoke components collected in the cambridge filter pad and cigarette filter was different with a different grade and stalk position of tobacco leaves. In high stalk position of tobacco leaves, the portion of smoke components collected in the cambridge filter pad was also increased. The average nicotine, water, and tar removal efficiency by a cigarette filter in a flue-cured tobacco were 37%, 64%, and 48%, respectively. Compared with flue-cured tobaccos, smoke components of burley tobaccos had high nicotine and low water removal efficiency by a cigarette filter. The average ratio of nicotine/tar and CO/tar of flue-cured tobaccos and burley tobaccos were 0.097, 1.22, 0.094, and 0.97, in order. Nicotine/tar ratio was decreased and CO/tar ratio was increased in low stalk position.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.135-141
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• 1989

The experiment was conducted to obtain basic information on breeding of flue-cured tobacco varieties. Nine cultivars and partial diallel set of 36 F1 hybrides were grown at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1983. Estimated heritability in the narrow-sense ranged from 66.21% to 94.12% for yield, leaves per plant, days to flower, leaf weight, leaf width, leaf shape, nicotine content and reducing sugar content, while that for stalk height, leaf length, midrib weight and midrib width ranged from 28.12% to 56.25%. The genotypic correlations were positive among yield, leaf weight, leaf length, leaf width, midrib weight and midrib width in the middle leaves, days to flower, nicotine content and reducing correlated with leaf length than leaf width. At the path coefficient analysis of the effect of leaf and midrib characters upon yield according to stalk position, leaf weight, leaf width and midrib width in the middle leaves, and leaf weight, and leaf width in the top leaves showed high direct effects.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.173-176
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• 2006

The relationship between source leaf position and photo-assimilate translocation and distribution was characterized for tomato (Lycopersicon esculentum Mill) grown in the greenhouse. Three different positions of source leaf on the stem (first node above or below the first fruit cluster and $5^{th}$ node above the first fruit cluster) were tested for their influence on $^{14}CO_2$ assimilation and transfer to different parts of the plant. The leaves at the $5^{th}$ node above the first fruit cluster transferred the highest (57%) proportion of $C^{14}$ to other plant parts, followed by leaves home on the first node below the first fruit cluster (50%), and the first node above the first fruit cluster (39%). In all treatments, fruits served as the strongest sink for $C^{14}$, followed by stem, leaf, and root tissues. The leaf home on the $5^{th}$ node above the first fruit cluster transferred the largest amount of $C^{14}$ to the second fruit cluster.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.79-80
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• 2001

This study was conducted to estimate rooting and shooting in single-node cuttings (SNC) of roses 'Rote Rose' and 'Teresa' to several conditions: growth stage, node position, and leaf area of cutting, so that single-stemmed roses (SSR) could be used in rose factory system. There was no effects of growth stage of flowering shoots far cutting on the rooting and shooting of SNC in both of the two cultivars. However, the node position and leaf area of cuttings significantly affected the rooting and shooting of SNC: the speed was accelerated with larger leaf area and upper node cuttings, but the rate showed little difference as above 95%. Based on above results, rooting and shooting in SNC was forced by leaf area mainly, followed by node positions. On the other hand, flowering rate of shoots from SNC was improved mainly with larger leaf area in cuttings. Shoots of 45cm-longer, qualified for rose factory system, increased with lower node and larger leaf area significantly. Therefore, it could be said that the potential growth of shoots from SNC would be influenced mainly by leaf area, followed by node position on cutting.

• Progress in Medical Physics
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• v.29 no.2
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• pp.66-72
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• 2018

The proper position of a multi-leaf collimator (MLC) is essential for the quality of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) dose delivery. Task Group (TG) 142 provides a quality assurance (QA) procedure for MLC position. Our study investigated the QA validation of the mechanical leaf gap measurement and the maintenance procedure. Two $VitalBeam^{TM}$ systems were evaluated to validate the acceptance of an MLC position. The dosimetric leaf gaps (DLGs) were measured for 6 MV, 6 MVFFF, 10 MV, and 15 MV photon beams. A solid water phantom was irradiated using $10{\times}10cm^2$ field size at source-to-surface distance (SSD) of 90 cm and depth of 10 cm. The portal dose image prediction (PDIP) calculation was implemented on a treatment planning system (TPS) called $Eclipse^{TM}$. A total of 20 VMAT plans were used to confirm the accuracy of dose distribution measured by an electronic portal imaging device (EPID) and those predicted by VMAT plans. The measured leaf gaps were 0.30 mm and 0.35 mm for VitalBeam 1 and 2, respectively. The DLG values decreased by an average of 6.9% and 5.9% after mechanical MLC adjustment. Although the passing rates increased slightly, by 1.5% (relative) and 1.2% (absolute) in arc 1, the average passing rates were still within the good dose delivery level (>95%). Our study shows the existence of a mechanical leaf gap error caused by a degenerated MLC motor. This can be recovered by reinitialization of MLC position on the machine control panel. Consequently, the QA procedure should be performed regularly to protect the MLC system.