• Advances in aircraft and spacecraft science
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• v.6 no.2
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• pp.145-156
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• 2019

As the industrial desire for a step change in productivity within the manufacture of composite structures increases, so does the interest in Through-Thickness Reinforcement technologies. As manufacturers look to increase the production rate, whilst reducing cost, Through-Thickness Reinforcement technologies represent valid methods to reinforce structural joints, as well as providing a potential alternative to mechanical fastening and bolting. The use of tufting promises to resolve the typically low delamination resistance, which is necessary when it comes to creating intersections within complex composite structures. Emerging methods include the use of 3D woven connectors, and orthogonally intersecting fibre packs, with the components secured by the selective insertion of microfasteners in the form of tufts. Intersections of this type are prevalent in aeronautical applications, as a typical connection to be found in aircraft wing structures, and their intersections with the composite skin and other structural elements. The common practice is to create back-to-back composite "L's", or to utilise a machined metallic connector, mechanically fastened to the remainder of the structure. 3D woven connectors and selective Through-Thickness Reinforcement promise to increase the ultimate load that the structure can bear, whilst reducing manufacturing complexity, increasing the load carrying capability and facilitating the automated production of parts of the composite structure. This paper provides an overview of the currently available methods for creating intersections within composite structures and compares them to alternatives involving the use of 3D woven connectors, and the application of selective Through-Thickness Reinforcement for enhanced damage tolerance. The use of tufts is investigated, and their effect on the load carrying ability of the structure is examined. The results of mechanical tests are presented for each of the methods described, and their failure characteristics examined.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.454-459
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• 2009

The secondary growth of garlic depreciates the quality of a bulb and, in the worse cases, makes it difficult to be used as a seed bulb due to many insertions of small cloves in the seed bulb. Therefore, the effect of soil temperature, seedtime, and fertilization rate on the secondary growth of the big bulbils of Namdo garlic has been examined. When we analyzed into the growth characteristics of big bulbils of Namdo garlic under different fertilizer application levels (50% increased fertilization, experimental fertilization and 50% decreased fertilization), the plant height, numbers of leaf, sheathe diameter, leaf length, and leaf width were the best in 50% increase of the test rate of fertilizer. The occurrence rates of secondary growth were 34.2% in 50% decrease of the test rate of fertilizer, 44.3% in the test rate, and 54.1% in 50% increase of the test rate of fertilizer. In other words, the occurrence rate of secondary growth increased by increasing the fertilization rate. While the average harvested bulb weight were 34.1g in 50% decrease of the test rate of fertilizer, 35.1g in the test rate of fertilizer, and 33.9g in 50% increase of the test rate of fertilizer, there were no changes in the number of cloves under different fertilization rates. As the correlation diagram between the soil temperature and occurrence of the secondary growth showed very high relation with 0.892~0.997, the secondary growth in cultivation of Namdo garlic big bulbils had considerably close correlation with the soil temperature. As the earlier the seedtime was, the growth of the above-groundparts including the plant height, numbers of leaf, and sheath diameter were the better. The averages of bulb weight were 36g in the mid September sowed seed bulb, 29.6g in the late September sowed seed bulb, and 27.9g in the early October sowed seed bulb. Overall, our results showed that the bulb size is dependent on the seedtime and the seedtime has no particular effects on the secondary growth.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.820-828
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• 2015

This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.72-72
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• 2019

This study compared the growth characteristics of A. gigas according to the transplanting season, in the cultivation located in Yeongju, Gyeongsangbuk-do, transplanted in the autumn and spring. As a result of that the plant survival rate were observed the highest autumn transplanting (9.4%; autumn-92.2%, spring-82.8%) and bolting rate were observed lowest spring transplanting (7.1%; autumn-37.3%, spring-30.2%). Growth characteristics (height, leaf length and width, stem diameter) were observed the highest autumn transplanting in June and highest spring transplanting in August. The early growth is high growth due to long rooting time in autumn transplanting, but the difference in the ground growth between the two experiments was insignificant when the main growth period was from June to August. Further analysis of the growth characteristics and marker components of roots of A. gigas can be used to determine the optimal planting time and the establishment of high quality cultivation technology.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.608-615
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• 2015

Garlic (Allium sativum L.) has been used as both food and medicine in many cultures for thousands of years. Garlic cultivars are completely sterile and propagated through vegetative method. Collection of a large number of fertile accessions of these genus is needed to explore genetic variability. In order to investigate genetic variation among Allium species and its possibilities for direct cultivation in Korea, we characterized 12 accessions of A. longicuspis, flowering wild garlic which had collected from Central Asia, the main center of garlic diversity. Most of A. longicuspis accessions showed higher over-wintering and bolting rate, longer scape length and more number of bulbils than Korean landraces cultivar, Danyang and Euiseong, but A. longicuspis accessions exhibited smaller size of bulbs and bulbils. Most accessions of A. longicuspis had more number of cloves per bulb, except K229596 and K248824 than Korean landraces. All the accessions of A. longicuspis from Central Asia had complete bolters having many flowers and topsets in umbel. Further studies of A. longicuspis should focus on securing true seeds through removal of topsets and crosses among accessions to create the genetic variability.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.250-260
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• 2019

This study assessed clove germination, shoot growth, photosynthesis and bulb development of southern-type garlic (Allium sativum L.) in a temperature gradient tunnel (TGT), to examine the impacts of increases in temperature on the growth of garlic and find a way to minimize them. The temperatures in the middle and outlet of the TGT were 3.2℃ and 5.8℃ higher, respectively, than the ambient temperature at the tunnel inlet. The germination of garlic cloves was late at temperatures of ambient+3℃ (in the middle of the TGT) and ambient+6℃ (at the outlet) than at ambient temperature (at the inlet). However, bolting and the timing of maximum leaf number per plant were faster at ambient+3℃ or +6℃ than at ambient temperature. Shoot growth was generally greater at ambient temperature. Bulb growth did not significantly differ according to cultivation temperatures, but fresh and dry weights were slightly higher at ambient temperature and ambient+3℃ in the late growth stage. The photosynthesis rate (A), stomatal conductance (g_s), and transpiration rate (E) were higher at ambient+3℃ than at ambient temperature. Furthermore, at ambient+3℃, the net photosynthetic rate (A_max) was high, while the dark respiration rate (R_d) was low. At ambient temperature and ambient+3℃, bulb development was healthier, resulting in better productivity and more commercial bulbs, while at ambient+6℃, the bulbs were small and secondary cloves developed, resulting in low commercial value. Therefore, at elevated temperatures caused by global warming, it is necessary to meet the low-temperature requirements before clove sowing, or to delay the sowing time, to improve germination rate and increase yield. The harvest should also be advanced to escape high-temperature stress in the bulb development stage.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.187-192
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• 1994

This study was conducted to evaluate the effect of herbIcides on weed control, growth characteristics and yield in Angelica gigas NAKAI, after transplanting it to the field. All herbicids treated had no effect on the emergency period, bolting rate, and growth characteristics of A. gigos. Simazin wp, methabenzthiazuron wp were slightly harmful, but linuron wp pendimethalin ec, triflurain ec had no injury on the A. gigas, even with double dosage level. Under the treatment of pendimethalin ec, linulon wp, effect of weed control valuae at 55 days after transplanting was 89.6, and 88.3 respectively with 5 or 7 species of weeds appearing. Broadleaf weeds f?ere abundant than grasses, and the major weeds were C. albam, C. flexuos, D.sanguinalis, and E. arvense. Dry yield were increased somewhat more with herbicides than by hand weeding, even with double dosage level.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.267-271
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• 1995

To improve regeneration efficiency of Brassica campestris ssp. pekinensis (chinese cabbage) in vitro, the effect of ehtylene inhibitors [AgNO$_3$ and silver thiosulfate (STS)] and optimal age of explantse were investigated. On the effect of ethylene inhibitors either 100 $\mu$M of AgNO$_3$ or 5 $\mu$M of STS enhanced shoot regeneration from cotyledons when it was added in basal shoot induction media(MS salts, B5 vitamine, sucrose 2%, BA 2.0mg/L, NAA 1.0mg/L). But at higher concentrations, AgNO$_3$ induced abnormal shoots, and STS greatly reduced regeneration frequency. On the other hand, the maximum regeneration rate was obtained from the cotyledons taken from 3-day old seedlings. However there was no distinctive effect among the containers used for cultivation. The most optimal condition of root induction was a minimal Murashige and Skoog media containing 0.1 mg/L NAA. In order to induce bolting and flowering from in vitro regenerated chinese cabbage, the plant were healed at 4$^{\circ}C$ for weeks in a cold chamber. When they were planted in pots, the plane produced phenotipically normal flowers and seeds. The overall results suggest that ethylene inhibitors promote regeneration of shoot from cotyledons of chinese cabbage without alleviating fertility.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.97-103
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• 1993

Relationships between crown diameter divided into the small$(0.3{\sim}0.5cm)$, the medium$(0.5{\sim}0.7cm)$ and the large seedling$(0.7{\sim}0.9cm)$ by the size of crown diameter of Angelica gigas and topdressed nitrogen level of 0, 50, 70 and 100% were conducted to study on growth and yield of two year-planted A. gigas in Suwon. The larger of the crown diameter, the better of the dry weight of leaf and root of A. gigas. Growth of the plane was rapidly increased on June and August, but slowly increased on July and that of root was increased until October while decreasing the aerial stem growth from September. Lower top dressed nitrogen level in the larger seeding was greatly increased the bolting rate compared to the medium or small seedlings. Yields of dried root weight per 10a were 441kg for the large, 373kg for the medium, and 378kg for the small seedling, and weight of the higher nitrogen per 10a were more increased than that of the lower dressed nitrogen treatment.