• Journal of Ginseng Research
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• 제5권2호
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• pp.85-91
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• 1981

Ginseng seeds were gathered from 3,4,5 and 6 years of age and were classified into four qroups (below 4mm, 4∼5mm, 5∼6mm and above 6mm in across sieve). They were sown in seedling bed and some characters were investigated in each qroup of seed size. 1. The distribution of seed size of below 4mm, 4-5mm, 5-6mm and 6mm were 23.7%, 60.8%, 12.4% and 4.5%, respectively. 2. The ratio of seed coat dehiscence was not affected by seed size but emergence ratio and emerging vigor were superior in large seed. 3. The large seed showed superiority in stem length, stem diameter, leat and also in root length, root diameter and root weight. but diseased root was not affected by seed size. The effect of age(seed harvest) was not significant on all those characters.

• Journal of Chest Surgery
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• 제46권5호
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• pp.353-356
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• 2013

A 74-year-old man was diagnosed with aortic root aneurysm and two-vessel coronary disease. Echocardiographic assessment revealed an enlarged sinus of Valsalva 60 mm in diameter with mild aortic regurgitation. Florida sleeve repair was performed using a vascular graft combined with coronary artery bypass grafting. The postoperative course was uncomplicated and follow-up echocardiographic evaluations showed an aortic root diameter of 38 mm without aortic insufficiency up to 1 year after surgery.

• Journal of Plant Biology
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• 제36권2호
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• pp.177-182
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• 1993

The root nodules of Elaeagnus umbellata were coralloid-shape due to repeated dichotomous branching of nodule meristem. The filamentous endophyte with vesicle cluster ranging from 30 ${\mu}{\textrm}{m}$ to 60 ${\mu}{\textrm}{m}$ in diameter was present only in the cortical cells. The isolated endophytes in vitro culture showed typical Frankia morphology, consisting of highly branched hyphae ranging from 0.8 ${\mu}{\textrm}{m}$ to 1.0 ${\mu}{\textrm}{m}$ in diameter, terminal and intrahyphal sporangia varing in shape and size up to 60 ${\mu}{\textrm}{m}$ in length and laminated vesicles. Its infectivity and effectivity were confirmed by induction of nitrogen-fixing root nodules on the inoculated seedlings of two Elaeagnus species. Consequently, the isolate was confirmed as a true symbiont of Elaeagnus umbellata root nodule and named Frankia EuIK1.

• Journal of Plant Biology
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• 제28권1호
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• pp.9-20
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• 1985

물오리나무와 사방오리나무의 뿌리 줄기 및 가지에 있어서 목부요소의 크기의 변이에 관해서 연구하였다. 도관요소의 직경은 뿌리에서 가장 넓고 그 다음은 줄기이며 가지에서 가장 좁다. 그런데 도관요소의 길이는 줄기에서 가장 길고 다음은 뿌리이며 가지에서 가장 짧은 것으로 밝혀졌다. 섬유의 직경 및 길이는 뿌리에서 가장 넓고 길며 그 다음은 줄기 가지의 순이다. 각 기관의 일정위치에서 중심부로부터 연륜이 증가함에 따라 목부요소의 크기는 뚜렷하게 증가되었다.

• 한국조경학회지
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• 제31권5호
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• pp.1-10
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• 2003

The purpose of this study was to verify the shore margin protection effect of a root system developed from direct sticking of Salix gracilistyla Miq., focusing on the reinforcement of soil shear strength. The materials were 20cm long sticks whose average diameter and weight were 7.52mm and 14.58g respectively, and sandy loam(Sand 60.36%, Silt 28%, Clay 11.64%), whose maximum dry weight(${\gamma}$$_{dmax}$) was 1.59gf/㎤ at the water ratio( $W_{opt}$) 13.8%. The direct shearing test(KS F 2343) was applied to cylindric columms(diameter 132mm) of pure soil and two years old root reinforced soil. At each condition of vertical stress, 10N/$ extrm{cm}^2$, 14.41N/$\textrm{cm}^2$ and 18.82 N/$\textrm{cm}^2$, five soil+root columns were sheared. After shear tests, the root area ratio and soil moisture on the shear plane were measured. The results of this research were as follows: 1. The average of root area ratio was 1.86% and the soil moisture 14.67%. 2. Two years old root system was found to increase the soil shear strength of pure soil in terms of Cohesion(C) and Inner friction Angle($\phi$) as follows. 3. The relationship between root area ratio and the increased shear strength can be presented with the following equation, $\Delta$S ≒ 0.33ㆍ TrㆍAs/A $\Delta$S : Increased Shear Strength Tr : Average Tension Strength of Root, Ar/A : Root Area Ratioioage Tension Strength of Root, Ar/A : Root Area Ratio

• Plant Resources
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• 제4권1호
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• pp.13-25
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• 2001

Growth and yield of licorice were investigated under the different conditions of photoperiod and shading in order to establish its cultural practice for the domestic production with the aim to substitute the import. The photoperiod was adjusted to 8,10, and 12 h by shielding plants from the light with blackout curtain. Large seedlings(11-20g) appeared to be affected by photoperiod since around 65 days. Most of growth parameters, including plant height, number of leaf, fresh and dry weight of plant and root, were the highest in 12 h photoperiod among all the photoperiod levels, excepting stem diameter which was the highest in 10 h photoperiod(4.5mm). Each photoperiod was similar to each other in root length and diameter. Small seedlings(4-l0g) showed a similar trend to large seedlings. The results from field photoperiod experiment demonstrated that 12 h photoperiod was also the best among three photoperiod treatments in plant height, stem diameter, number of leaf, root length, fresh and dry weight of plant and root. The effect of shading was tested under the three levels of control (0%), half-shading (55%), and full shading (90%). Shading remarkably suppressed the growth and yield, compared to no-shading. Although plant height and root length were little affected by the shading, stem and root diameters were heavily reduced.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.56.1-56.11
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• 2021

Objectives: This study evaluated 2 nickel-titanium rotary systems and a complementary protocol with an ultrasonic tip and a small-diameter instrument in flattened root canals. Materials and Methods: Thirty-two human maxillary second premolars with flattened canals (buccolingual diameter ≥4 times larger than the mesiodistal diameter) at 9 mm from the radiographic apex were selected. The root canals were prepared by ProDesign Logic (PDL) 30/0.01 and 30/0.05 or Hyflex EDM (HEDM) 10/0.05 and 25/0.08 (n = 16), followed by application of the Flatsonic ultrasonic tip in the cervical and middle thirds and a PDL 25/0.03 file in the apical third (FPDL). The teeth were scanned using micro-computed tomography before and after the procedures. The percentage of volume increase, debris, and uninstrumented surface area were analyzed using the Kruskal-Wallis, Dunn, Wilcoxon, analysis of variance/Tukey, and paired and unpaired t-tests (α = 0.05). Results: No significant difference was found in the volume increase and uninstrumented surface area between PDL and HEDM (p > 0.05). PDL had a higher percentage of debris than HEDM in the middle and apical thirds (p < 0.05). The FPDL protocol resulted in less debris and uninstrumented surface area for PDL and HEDM (p < 0.05). This protocol, with HEDM, reduced debris in the middle and apical thirds and uninstrumented surface area in the apical third (p < 0.05). Conclusions: High percentages of debris and uninstrumented surface area were observed after preparation of flattened root canals. The HEDM, Flatsonic tip, and 25/0.03 instrument protocol enhanced cleaning in flattened root canals.

• 한국자원식물학회지
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• 제26권6호
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• pp.709-717
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• 2013

The objective of this study was to examine the effect of root pruning intensity in combination with different initial seedling size on the growth of transplanting seedlings of Quercus acutissima. One-year-old seedlings were divided into three groups depending on their height, i.e. small (< 15 cm), medium (25-35 cm) and large size (35 cm <). Root of seedlings was pruned by three intensity such as, leaving 5 cm (severe), 10 cm (medium) and 15 cm (light) of taproot from the root-collar. After one year, we investigated survival rate, height and root-collar diameter (RCD) increment and final shoot dry weight. Also we measured characteristics of newly developed lateral roots such as number, total length, dry weight and diameter. Severe root pruning showed the lowest survival rate in all seedling size. Height increment, RCD increment and shoot dry weight were decreased with increasing intensity of root pruning. Seedlings of medium and light root pruning showed similar above-ground growth and dry weight of lateral roots. More large seedlings showed good survival rate, height increment and final shoot dry mass in all root pruning intensity. Therefore, one-year-old seedlings of Q. acutissima should be pruned taproot by 10 cm and transplanted to obtain excellent performance and increase the efficiency of transplanting work. Based on the findings of this study, it is important that applying to different root pruning intensity depending on initial seedling size for producing 2-year-old seedlings with excellent growth and high quality.

• 한국농공학회논문집
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• 제56권6호
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• pp.149-158
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• 2014

The effects of spot cooling on growing ever-bearing strawberry in hydroponic cultivation during summer by spot cooling system was estimated in plastic greenhouse located in Pyeongchang. The temperature of cooling water was controlled by heat pump and maintained at the range of $15{\sim}20^{\circ}C$. Cooling pipes were installed in root zone and very close to crown. Spot cooling effect was estimated by applying system in three cases which were cooling root zone, crown plus root zone, and crown only. White low density polyethylene pipe in nominal diameter of 16 mm was installed on crown spot, and Stainless steel flexible pipe in nominal diameter of 15A was installed in root zone. Crown and root zone cooling water circulation was continuously performed at flowrates of 300 ~ 600 L/hr all day long. Strawberry yields by test beds were surveyed from Aug. 1 to Sep. 30. The accumulated yield growth rate compared with a control bed of crown cooling bed was 25 % and that of crown plus root zone cooling bed was 25 % and that of root zone cooling bed was 20 %. The temperatures of root spot in root zone cooling was maintained at $18{\sim}23.0^{\circ}C$ and that of crown spot in crown cooling was maintained at $19{\sim}24^{\circ}C$. Also, the temperatures of root spot in crown plus root zone cooling bed was maintained at $17.0{\sim}22.0^{\circ}C$ and that of crown spot was maintained at $19{\sim}25^{\circ}C$.

• 한국환경농학회지
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• 제7권1호
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• pp.21-25
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• 1988

비소(砒素)의 토양처리(土壤處理)에 의(依)한 수도근(水稻根)의 생태적(生態的) 특성(特性)을 조사(調査)하기 위해 비소를 토양이 농도별(濃度別)로 처리(處理)하고 수도(水稻)를 재배(栽培)하여 근의(根) 제형질(諸形質) 및 조직내(組織內)의 변화등(變化等)을 조사(調査)하여 얻어진 결과(結果)는 다음과 같다. 수도(水稻)의 근수(根數) 근장(根長) 및 근경(根徑)은 토양중(土壤中) 비소농도(砒素濃度)가 증가(增加)함에 따라 현저히 감소(減少)되었으며 중심주(中心柱)의 직경(直徑)도 크게 좁아졌다. 한편 토양(土壤)에 비소(砒素)를 처리(處理)한 구(區)에서는 수도근(水稻根)의 피층내(皮層內) 이상세포(異常細胞)가 발생(發生)하였으며 비소처리농도(砒素處理濃度)가 높을수록 그 수가(數) 더 증가(增加)하였다. 근의(根) 부위별(部位別) 이들(細胞)의 발생정도(發生程度)를 보면 이들 세포(細胞)는 근단부(根端部)를 제외(除外)한 중간부(中間部)와 상위부(上位部)에서만 발생(發生)하였다. 또한 이들 세포(細胞)는 표피조직(表皮組織)이 없는 근(根)의 형상(形狀)을 하고 있었다. 따라서 토양중(土壤中) 비소처리(砒素處理)에 따라 수도근(水稻根)의 피층내(皮層內) 이상세포(異常細胞)의 발생(發生)은 뿌리에 유해물질(有害物質)을 과다(過多)하게 축적(蓄積)한 근에(根)서는 뿌리의 수분(水分) 및 무기양분(無機養分)의 흡수기능(吸收機能)이 저해(沮害)를 받으므로 이를 보충(補充)하기 위한 수단(手段)으로 이들 세포(細胞)가 발생(發生)되었거나, 뿌리에 유해(有害)한 물질(物質)의 침투(侵透)에 대(對)한 방어수단(防禦手段)으로 발생(發生)된 것으로 추정(推定)된다.