• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.421-426
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• 2012

The effect of synthesis conditions such as various organic material and composition of organic-inorganic material in ozone resistance and surface characteristic of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Organic-inorganic hybrid coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 2,2,2-trifluoroethylmethacrylate, and various organic materials with acrylate group, bar-coated on substrates using applicator and densified by UV-curing. It was found that ozone resistance and surface hardness of the coating film was increased with contents of TEOS. It was also found that ozone resistance of coating film was increased with contents of 2,2,2-trifluoroethylmethacrylate. On the other hand, surface hardness was decreased with increase of 2,2,2-trifluoroethylmethacrylate. In addition, Surface hardness of coating film was increased with the addition of aliphatic urethane acrylate. It was also found that the transmittance of coating films was not influenced by content of TEOS and 2,2,2-trifluoroethylmethacrylate. In addition, the coating film exhibited high transmittance of above 90%.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.403-409
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• 2012

Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate, and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATWPUD) was synthesized by capping aniline on the NCO group of the prepolymer. Subsequently, ATWPUD was mixed with multi-walled carbon nanotube (MWCNT) to yield coating solutions, and the mixture was coated on the polycarbonate substrate. The surface resistance ($10^{7.6}{\sim}10^{7.7}{\Omega}/cm^2$) of coating films from ATWPUD showed better conducting properties than that ($10^{10.9}{\Omega}/cm^2$) from pure waterborne polyurethane dispersion (WPUD) when MWCNT was mixed. Also, the surface resistance of coating films was increased, but the pencil hardness and adhesion were decreased with increasing the amount of MWCNT added in the ATWPUD.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.247-252
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• 2017

Hydrophilic coating solutions were prepared by reacting a silane coupling agent, aminosilane with colloidal silica (15~20 nm in diameter). Hydrophilic coating films were also obtained by depositing the hydrophilic coating solutions on polycarbonate substrates by dip-coating and subsequently by thermal curing at $120^{\circ}C$. During this process, the effect of types of aminosilane was studied on the properties of coating films. As a result, coating films, prepared with 3-aminopropyltriethoxysilane (APTES) as aminosilane, showed contact angles of $25{\sim}44^{\circ}$ and a poor pencil hardness of B. On the other hand, coating films, prepared with 3-aminopropyltrimethoxysilane (APTMS) as aminosilane, exhibited contact angles of $26{\sim}37^{\circ}$ and a good pencil hardness of 2H.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.335-339
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• 2007

In order to overcome the problem of poor hardness of transparent polycarbonate (PC) sheets, organic-inorganic hybrid hard coating solutions, which show a high refractive index above 1.58, were made by the sol-gel method. These hybrid coating solutions were obtained from mixture of titanium tetraisopropoxide (TTIP), and (3-glycidoxypropyl)trimethoxysilane (GPTMS). The PC sheets were spin-coated, and cured at $120^{\circ}C$ for 2 hr. Change of refractive index in the range of 1.53-1.61 was obtained by varying the GPTMS content. The refractive index of the coated film decreased with increasing the GPTMS content, while the pencil hardness of the coated film was found to increase with increasing the GPTMS content.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.251-255
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• 2020

In 2019, the ash whitefly, Siphoninus phillyreae (Haliday, 1835), was firstly found on a pear tree in Jinju-si, Gyeongsangnam-do. From occurrence survey, we confirmed that S. phillyreae was occurred in seven cities, Busan, Changwon, Jinju, Gwangyang, Suncheon, Goheung, and Goseong. In addition, seven plants, such as Punica granatum, Pyrus pyrifolia, Cydonia oblonga, Prunus mume, Crataegus pinnatifida, Eriobotrya japonica, Photinia glabra, Pyracantha angustifolia, Lagerstroemia indica, and Malus prunifolia, were detected as hostplants. In this study, we present the first report of this species in Korea and describe the damage caused by S. phillyrease and its taxonomic information.

• Korean Journal of Plant Taxonomy
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• v.36 no.4
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• pp.309-333
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• 2006

Examined were the vegetative and reproductive characters such as external morphology, anatomy (leaf petiole, blade and stem), pollen and nutlet for the taxonomic revision of Elsholtzia in Korea. The inflorescence of all studied taxa of Elsholtzia in Korea is secund and 0.5-10 cm long. Leaves are ovate or nearly and $0.2-10{\times}0.2-6.0cm$. The shapes of inflorescence and leaves are very useful taxonomic characters. The stomata types are anomocytic and diacytic. The morphology of nutlet is ovoid and pitted in surface pattern of exocarp. All studied taxa are myxocarpy. The pollen grains are of medium size and subprolate in shape, and have typical bi-reticulate exine surface. Four species are recognized for Korean Elsholtzia by the identification key and descriptions in this study.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.115-127
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• 2005

Two anatomical features of leaves, transverse section of midribs and petioles, were examined for nine species of five genera of Thymelaeaceae, Daphne L. -4 spp., Diarthron Turcz. -1 sp., Edgeworthia Meisn. -1 sp., Stellera L. -1 sp., Wikstroemia Endl. -2 sp., using light microscopy and scanning electron microscopy. In terms of shape of upper side, three types were observed, i.e., flattened, depressed, and raised. Outline of petioles is mostly semi-circular or circular in transverse section, with two distinct wings/weakly developed wings or without wings. Other characters besides anatomical features of leaves such as vascular bundle tissues, crystal, tannin are also described in details. Finally, we briefly discussed the systematic significance of the anatomical features of leaves for identification of Korean Thymelaeaceae.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.459-476
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• 2008

Taxonomic characteristics of spores of 17 species belonging to 6 genera of the Korean Thelypteridaceae are examined. Description of each species and key to the species are provided. Spores of Korean Thelypteridaceae are monad and monolete with bilateral symmetry. Perispore, the sporoderm of spore, was found in all the species examined. The perispores and exospores of Thelypteris japonica var. japonica, T. japonica var. glabrata and Pseudocyclosorus subochthodes are much similar to each other, but the rest of taxa examined shows diverse patterns of the surface ornamentation of perispores and exopores enough to distinguish genera and sometimes to distinguish species in some genera. Previous study reported that perispore is not easily distinguished from exospore in Cyclosorus and Leptogramma. However, three species of Cyclosorus examined here show different pattern having scabrate or verrucate exospores and cristate or echinate perispores. Leptogramma pozoi ssp. mollisima also have echinate perispore and fossulate exospore. Macrothelypteris oligophlebia var. elegans and M. viridifrons have scabrate exospore which is contrast to previous report of reticulate exospore. Thelypteris glanduligera, T. angustifrons and T. laxa show same patterns of perispore and exospore with reticulate perispore and fossulate exospore and hence cannot be distinguished by spores only.

• Korean Journal of Plant Taxonomy
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• v.45 no.2
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• pp.178-182
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• 2015

Stellaria sessiliflora Y. Yabe (Caryophyllaceae), which is known to be distributed throughout Japan excluding Okinawa, was recently found on Jeju Island in Korea. Reports on the Japanese flora state that this species is distributed on Jeju Island, and a photograph of one specimen (Slide No. 6294) collected from Jeju Island by Ohwi in May 1935 confirms this. Additionally, specimens at the National Arboretum and Korea Forest Research Institute indicate that S. sessiliflora has occurred on Jeju Island for a considerable amount of time. However, the species has never been officially listed in the flora of Korea. Stellaria sessiliflora is distinguished from S. media by having broader leaves with a slightly undulate margin, petiolate leaves on the upper part of the stem, and 10 stamens. The local name 'Geu-Neul-Byeol-Kkot' is given to the species based on its shady habitat under deciduous broadleaf forest. Details of the morphological characters, an illustration, the type specimen, voucher specimen data, and photographs of Stellaria sessiliflora in Korea are presented.

• Korean Journal of Plant Taxonomy
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• v.45 no.2
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• pp.173-177
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• 2015

An unrecorded variety, Viola betonicifolia var. albescens (Nakai) F. Maek. & T. Hashim., was reported from Jeonju, Imsil, and Jinan in Jeollabukdo province, Korea. Viola betonicifolia var. albescens shares several characteristics with its related species V. patrinii Ging. (i.e., white flowers, long triangular blades, winged petioles, green pedicels, and a rounded sepal appendage), but is distinct from V. patrinii, which has a glabrous winged petiole, colorless upper petals, glabrous upper petals, and higher elevation habitats, in that it has a pubescent winged petiole, striate-colored upper petals, bearded upper petals, and lower elevation habitats. It is also distinguished from V. lactiflora Nakai, which has glabrous wingless petioles, red pedicels, and a toothed sepal appendage.