• Title/Summary/Keyword: 띠 형성

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Synthesis of Naphthalimidopropyl Acrylate and GMA Copolymers and Their Physical Properties (나프탈이미도프로필 아크릴레이트와 GMA 공중합체의 합성과 물성)

  • Lim, Deok Jum;Oh, Seung Min;Kim, Boo Yoon;Park, Jae Kyung;Kang, Inn-Kyu;Seo, Kwan-Ho;Oh, Dae Hee
    • Polymer(Korea)
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    • v.38 no.4
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    • pp.535-543
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    • 2014
  • This work, which was about the synthesis of naphthalimidopropyl acrylate and GMA copolymers and their physical properties, investigated the compositions of the copolymer, the reactivity ratios of the monomer, resonance effect (Q), polar effect (e) and fluorescence of naphthalene. Azobisisobutyronitronitryl (AIBN) as an initiator was employed at $60^{\circ}C$ with dimethylformamide (DMF) of solvent for the copolymerization of NIPA. $r_1$ was found to be higher than $r_2$ from the reactivity ratios of the monomer obtained from Fineman-Ross (F-R), Kelen-$T{\ddot{u}}d{\ddot{o}}s$(K-T) methods. NIPA was found to be more copolymerized than GMA. $r_1{\cdot}r_2$ product was lower than 1, copolymerization was maked random-alternating type. The fluorescence spectrum of these polymers showed a weak monomer fluorescence band at 380 nm and a strong excimer fluorescence band at about 460 nm. Fluorescence life time of NIPA monomer showed fluorescence cover with UV 355 nm at room temperature, and life time showed $5.1449{\times}10^{-7}s$.

A CASE REPORT OF DENTINOGENESIS IMPERFECTA (상아질 형성 부전증에 대한 증례보고)

  • Kim, Jae-Gon;Lee, Doo-Cheol;Lee, Seung-Young;Lee, Seung-Ik;Baik, Byeoung-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.1
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    • pp.1-6
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    • 2000
  • Dentinogenesis imperfecta is an inherited disorder of dentin formation, usually exhibiting an autosomal dominant mode of transmission. Type I dentinogenesis imperfecta occurs in patients afflicted with osteogenesis imperfecta. Type II dentinogenesis imperfecta is not associated with osteogenesis imperfecta. Type III dentinogenesis imperfecta (Brandywine type) occurs in a racial isolate area in the state of Maryland. In all three types, teeth of both dentitions are affected with variable clinical appearances. The teeth are opalescent with the color ranging from bluish-gray to brown to yellowish. The dentin is abnormally soft, providing inadequate functional support to the overlying enamel. Although the enamel is normal, it fractures or chips away easily, exposing the occlusal and incisal dentin. The exposed soft dentin often undergoes rapid and severe functional attrition. The teeth exhibit bulb-shaped crowns with constricted cementoenamel junctions and thin roots. The teeth will exhibit varying stages of obliteration of the coronal and root pulpal chambers. The cementum, periodontal ligament and supporting alveolar bone appear normal. The enamel is normal. The mantle dentin remains nearly normal, whereas the remaining dentin is severely dysplastic. The dentinal tubules are disoriented, irregular, widely spaced, and usually larger than normal.

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Electron Microscopic Study on the Role of Actin Filaments during the Formation of Bile Canaliculi in Isolated Rat Hepatocyte Culture System (흰쥐에서 분리 배양한 간세포의 담세관 형성에 있어서 액틴미세섬유의 역할에 관한 전자현미경적 연구)

  • Park, Chang-Hyun;Chang, Byung-Joon;Uhm, Chang-Sub
    • Applied Microscopy
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    • v.29 no.4
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    • pp.437-450
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    • 1999
  • Bile canaliculi are the structure delivering bile secreted by hepatocytes into the bile passage. Bile secretion is mainly controlled by the cytoskeletal elements, mainly of actin in the microvilli, pericanalicular web. Most studies on the bile secretion have been done in viva situation, however, to control the various parameters in vitro culture system seem to be more useful. To set up an in vitro experimental system, the investigator isolated hepatocytes with an enzymatic method using a mixture of collagenase and hyaluronidase from normal Sprague-Dawley rat liver and cultured. Isolated hepatocytes were round and formed cords in culture. Microvilli covered the whole surface of hepatocytes. Bile canaliculi were formed between hepatocytes and were characterized by the presence of microvilli of various lengths and shapes mainly arising from small surface mounds. Actin filament core in the microvilli and pericanalicular actin web were incomplete. After cytochalasin D treatment, cultured hepatocytes were round but the surface were irregular with surfacen blebs, folds and grooves. Microvilli on the surface were scarce. Bile canaliculi were markedly dilated often with the detached junctional complexes. Bile canaliculi lacks microvilli almost completely and extended into the pericanalirular cytoplasm showing complex vacuolar and tubular structures by transmission electron mciroscopy. Pericanalicular actin web, intermediate filaments were hardly identified. Subsurface actin filaments were scattered scarcely under the cell membranes. These results suggest that hepatocytes isolated from rats can survive and form bile canaliculi in culture and the actin filaments are involved in the formation and/or maintenance of the bile canaliculi.

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The Effect of Melt Stoichiometry on the Native Defects of LEC GaAs (LEC GaAs의 점결함에 대한 Melt 조성의 영향)

  • 고경현;안재환
    • Journal of the Korean Ceramic Society
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    • v.28 no.2
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    • pp.141-145
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    • 1991
  • The effects of the melt stoichiometry on the concentration of electron and hole traps formed by intrinsic defects of LEC GaAs were studied employing DLTS measurement technique. The concentration of EL2 were varied from $10^{16}cm^{-3}$ to $10^{11}cm^{-3}$ when the arsenic atomic fraction in the melt ([As]/{[As]+[Ga]} varied from 0.5 to 0.42. Specifically, when the fraction falls below 0.46, the 띠2 concentration start to decrease sharply. For 68meV and 77/200meV traps, their concentration increase inversely with the arsenic atomic fraction and have the values in the range of TEX>$10^{15}cm^{-3}$ and $10^{14}cm^{-3}$, respectively. It is, therefore, concluded that these hole traps originated from the intrinsic acceptor defects including $GS^{AS}$.

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Rust of Lysimachia clethroides Caused by Puccinia dieteliana (Puccinia dieteliana에 의한 큰까치수영녹병)

  • Kim, Seong-Hwan;Lee, Tae-Soo
    • The Korean Journal of Mycology
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    • v.36 no.2
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    • pp.196-198
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    • 2008
  • A rust disease occurred on Lysimachia clethroides in Deogyusan National Park, Jeollabukdo. The typical symptoms of the disease appeared as small, yellowish spots on leaves at first. The spots then turned yellowish brown and powdery mass of blackish brown spores appeared on the lesions. Severely infected leaves blighted and eventually shriveled. Teliospores were yellowish brown in color, clavate or fusiform in shape and $38{\sim}62\;{\times}\;14{\sim}22\;{\mu}m$ in size, the apex rounded or obtuse, the base attenuated. Pedicels hyaline, persistence, up to $75{\mu}m$ long. The causal fungus was identified as Puccinia dieteliana based on mycological characteristics and host specificity.

Phenotypic Expression of the Non Molting Gene in The 'Non-molting of Nho' of Bombyx mori (돌연변이 불면잠$(nm^n)$ 의 불면형질의 발현)

  • 유현주;노시갑
    • Journal of Sericultural and Entomological Science
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    • v.35 no.2
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    • pp.93-99
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    • 1993
  • Studies were carried out to investigate physiological and biochemical analysis of recessive lethal mutant "nmn" and to observe the cuticle formation and dermal gland. All nmn homozygous larvae continued to eat a few mulberry leaves, and died without entering into molt. In case of artificial hatching, eggs had a higher nmn individual segregation ratio than in hibernating eggs. The percentage of nmn individuals with the hatching days was alike during 3days period. As a result of histological observation, nmn mutants dermal gland was different from normal dermal gland in form and size. Normal was formed new cuticle in the middle of the molting, but not in nmn mutant. Total protein content in haemolymph of the normal larva was more than that of nmn smutant and there was a difference between normal and nmn mutant protein components.omponents.

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Acclimation of Ectomycorrhizal Pine (Pinus densiflora) Seedlings Inoculated with Tricholoma matsutake by the Treatment of PDMP and Tween Solutions (송이균 접종으로 외생균근을 형성한 소나무 묘목의 PDMP 및 Tween 용액 처리에 의한 순화)

  • Park, Hyun;Lee, Bong-Hun;Ka, Kang-Hyeon;Ryu, Sung-Ryul;Bak, Won-Chull
    • Journal of Korean Society of Forest Science
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    • v.98 no.4
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    • pp.357-362
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    • 2009
  • Trials to find a method for overcoming the depletion of Tricholoma matsutake mycorrhiza from the artificially inoculated pine seedling (Pinus densiflora) when it is transplanted in situ were carried out. The culturing jars containing mycorrhizal seedlings were punched at the bottom to make the jar like a pot with keeping the soil structure of the original medium in vitro, and 8 kinds of irrigation solution were applied. Irrigation of distilled water caused disappearance of T. matsutake mycorrhizae, but biweekly irrigation of 2.5% PDMP (24 g potato dextrose broth, 3 g malt extract, 1 g peptone) solution or 0.5% Tween 80 solution until 3 months of acclimation could keep mycorrhizal association stronger. The percentage of mycorrhizal roots out of total length of roots was increased during the acclimation, and the acclimation rate reached up to 70%. Thus, we recommend that the mycorrhizal pine seedlings inoculated with T. matsutake would be acclimated before transplanting into the field.

Anthracnose Caused by Colletotrichum acutatum in Robinia pseudoacacia (Colletotrichum acutatum에 의한 아까시나무 탄저병)

  • Cheon, Wonsu;Jeon, Yongho
    • Research in Plant Disease
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    • v.22 no.2
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    • pp.127-131
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    • 2016
  • During the year 2014, black locust (Robinia pseudoacacia L.) had been observed with dark brown spots on the leaves at Andong, Cheongsong, Mungyeong in Korea. Symptoms initially appeared as small, black lesions on the leaves, and sometimes, the leaves become yellow and ultimately leads to fall off the leaves. The pathogenic fungus grown in potato dextrose agar was white or sometime gray with mycelia in tufts and from which numerous conidia were produced. The conidia were straight and fusiform in shape and measured $8.3-17.2{\times}2.5-4.1{\mu}m$. Internal transcribed spacer (ITS) rRNA sequence analysis for sequence similarity of the ITS region revealed 100% identity with nucleotide sequences for Colletotrichum acutatum. The morphological characteristics, pathogenicity and molecular data have been confirmed that the symptomatic pathogen was C. acutatum. This is the first report of anthracnose caused by C. acutatum on black locust in Korea.

Si 기판위에 형성된 ZnO 나노입자의 열처리 온도변화에 따른 구조적 성질과 전자적 성질에 관한 연구

  • Park, Geun-Gap;No, Yeong-Su;Park, Gyeong-Hun;Son, Dong-Ik;Kim, Tae-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.107-107
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    • 2010
  • ZnO는 상온에서 에너지 밴드갭이 3.37 eV 이고 엑시톤 속박에너지가 60 meV 인 넓은 에너지 띠를 가진 반도체이다. ZnO 반도체는 고에너지 영역에서 광투과율 및 에너지 수집율이 큰 특성을 가지고 있기 때문에 단파장 영역에서 작동하는 발광 다이오드나 반도체레이저 소자 응용에 사용되고 있다. 이와 더불어 액정디스플레이, 유기발광소자 및 태양전지에서 투명 산화물 전극으로 많은 응용이 되고 있다. 본 연구에서는 p-type Si 기판 위에 ZnO 나노입자 형성과 구조적 성질과 전자적 성질에 대하여 조사하였다. ZnO 나노입자를 형성하기 위해 ethanol에 zinc acetate dehydrate (5 wt%)을 적절히 분산시킨 $Zn(CH_3COO)_2H_2O\;+\;CH_3OH$ 용액을 스핀 코팅하여 산소 분위기에서 각각 $300^{\circ}C$, $500^{\circ}C$, $700^{\circ}C$$900^{\circ}C$로 각각 2시간 동안 열처리 하였다. X-ray 회절 실험 결과는 열처리 온도에 관계없이 ZnO (0001)의 피크가 관측되었다. 원자힘 현미경 이미지상으로 열처리 온도에 따른 ZnO 나노입자의 표면상태의 변화와 나노입자의 크기의 변화를 확인하였다. X-ray 광전자 분광 스펙트럼 결과는 Zn $2p_{3/2}$와 O 1s의 전자상태 스펙트럼을 분석하여 ZnO 나노입자가 형성됨을 보여주었다. 본 연구를 통하여 용액방법을 사용하여 제작된 ZnO 나노입자의 열처리 온도변화에 따른 구조적 성질과 전자적 성질을 이해하는데 도움을 줄 것이다.

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Influence of Surfactant on the Iodine Complex Formation of Some Non-ionic Polymers (비이온성 고분자의 Iodine 착물형성에 대한 계면활성제의 영향)

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1031-1037
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    • 2018
  • The formation of a complex between PVP or HPC and iodine was indicated by a red shift in the tri-iode band while PVA-iodine complex showed its characterized band around 500 nm in pure aqueous media. Addition of surfactant SDS resulted in a disapperance of the characteristic blue color of the PVA-iodine complex indicating that the complex is not formed in aqueous surfactant media. However in case of PVP or HPC, presence of the monomers of SDS favored the complex formation but in higher concentration, the micelles of SDS decreased the complex. Complexation was found to increase with increasing content of n-propanol in the system since n-propanol inhibits the formation of gels or microgels in the polymer solution. But in case of PVA-iodine complex, addition of n-propanol led to conversion of bigger polyiodides into smaller ones, which is indicative of increased intermolecular hydrogen bond interaction between propanol and PVA effecting a decrease in the PVA aggregate space.