• Title/Summary/Keyword: natural hybrid

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Study of Wrinkle Effect on Primary Natural Frequency of Nano-resonator (나노 공진기의 1차 고유진동수에 미치는 링클 영향 연구)

  • Yoon, Juil;Kang, Sang-Wook
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.12
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    • pp.1157-1163
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    • 2012
  • Natural frequency of a nano-resonator via nano transfer printing is studied. Through a nano transfer printing, the hybrid metal/polymer membrane may evolve a wrinkle. Natural frequency of a wrinkled hybrid membrane decreases significantly, as the amplitude to wavelength ratio becomes larger. To address the design limit of a hybrid nano resonator, we perform parametric study using finite element analysis. Specifically, we study the effects of the Young's modulus ratio of the metal/polymer membrane, thickness ratio and wrinkle amplitude to wavelength ratio, respectively. The results from the parametric studies can serve as guideline to design hybrid nano resonators.

Hybrid LVDC Circuit Breakers (저압직류용 하이브리드 차단기)

  • Hyo-Sung, Kim
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.6
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    • pp.489-497
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    • 2022
  • This work investigates the commutation characteristics of the current flowing through an electrical-contact-type switch to the semiconductor switch branch during the breaking operation of hybrid DC switchgear. A simple, reliable, low-cost natural commutation method is proposed, and the current commutation characteristics are analyzed in accordance with the conduction voltage drop of the semiconductor switch branch through experiments. A prototype 400 V/10 A class natural commutation type hybrid DC switchgear is set up. Its performance is verified, and its characteristics are analyzed.

Seed Setting and Viability and Fertility of Pollens in Families of Artificial and Natural Interspecific Hybrids in Lepidobalanus of Genus Quercus (참나무속의 인공 및 자연 종간잡종 가계의 종자결실 및 활력과 화분의 임성)

  • Lee, Jeong-Ho
    • Journal of Korean Society of Forest Science
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    • v.96 no.3
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    • pp.290-294
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    • 2007
  • Interspecific hybrid seedlings by artificial crossing of Genus Quercus (Q. serrata, Q. dentata, Q. mongolica var. crispula, Q. aliena) were planted at nursery in Tottori University. Seedlings of hybrids by natural crossing(Q. fabri and $Q.{\times}mccormickii$) were selected and planted at Hiruzen district in Tottori University. Artificial interspecific hybrid $F_1$ and natural hybrid $F_1$ bloomed when they were 4 years old and 3 years old, respectively. The pollen fertility and seed viability were investigated from the bloomed individuals in 2001. The germination percentages of the pollens of artificial interspecific hybrid were more than 84% except one individual, and the extension of pollen tubes was normal. The normal seed percentages of artificial interspecific hybrid were more than 90% similar to parents. Germination percentages of normal seed of natural crossing family were more than 64%, respectively, and selfed offsprings of Q. fabri, and $Q.{\times}mccormickii$ hade high reproductive ability.

Green Fluorescent Protein-reporter Mammalian One-hybrid System for Identifying Novel Transcriptional Modulators for Human $p14^{ARF}$ Tumor Suppressor Gene

  • Lee, Hye Jin;Yang, Dong Hwa;Yim, Tae Hee;Rhee, Byung Kirl;Kim, Jung-Wook;Lee, Jungwoon;Gim, Jin Bae;Kim, JungHo
    • Animal cells and systems
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    • v.6 no.4
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    • pp.317-322
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    • 2002
  • To improve conventional yeast one-hybrid screening, we have developed an efficient mammalian one-hybrid system that allows rapid isolation of com-plementary DNAs which are able to induce human p14$^{ARF}$. tumor suppressor gene. A 1.5 kb promoter region of p14$^{ARF}$ was fused to EGFP to generate ARF promoter-EGFP reporter vector. This reporter plasmid was stably trans-fected into NIH3T3 cells for generation of reporter cell line. When the reporter cell line was infected with E2F-1 together with excess amounts of empty vector, the cells that received the positive modulator were readily identifiable by green fluorescence using FACS. The GFP-positive cells were cloned directly from the cultured cells and expanded in bulk culture. The genomic DNAs from GFP-positive cells were prepared and the CDNA insert in integrated retroviral genome was recovered by PCR using primers annealing to the retroviral vector sequences flanking the insert-cloning site. This system should be useful for efficient screening of expression CDNA libraries in mammalian cells to identify novel upstream regulators for spe-cific genes by one-hybrid interaction.ion.

Purification and Properties of Escherichia coli-Corynebacterium nephridii Hybrid Thioredoxin

  • Sa, Jae-Hoon;Lee, Hee-Bong;Lim, Chang-Jin
    • BMB Reports
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    • v.29 no.2
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    • pp.116-121
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    • 1996
  • In earlier studies, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C-3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3 (N to C-terminal) and C3-E. The hybrid thioredoxins were overexpressed in E. coli from the cloned chimeric thioredoxin genes by a T7 promoter/polymerase system. To investigate the structure-function relationship of thioredoxin, we purified the E-C3 hybrid thioredoxin through ammonium sulfate fractionation, DEAE-cellulose chromatography, and Sephadex G-50 gel filtration. Its purity was examined on SDS-polyacrylamide gel electrophoresis and the molecular weight of the purified E-C3 hybrid thioredoxin was estimated to be 12,000. On native polyacrylamide gels, the purified E-C3 hybrid thioredoxin shows a much lower mobility than E. coli thioredoxin. E-C3 hybrid thioredoxin exhibits a 40-fold lower catalytic efficiency with E. coli thioredoxin reductase than E. coli thioredoxin. It was shown to catalyze the reduction of insulin disulfide by dithiothreitol. The purified E-C3 hybrid thioredoxin was also characterized in other aspects.

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Occurrence of a Natural Intergeneric Hybrid, Rhodeus uyekii${\times}$Acheilognathus signifer (Pisces : Cyprinidae) from Jojongcheon Bukhan River (각시붕어 Rhodeus uyekii와 묵납자루 Acheilognathus signifer (Pisces : Cyprinidae)의 속간 자연 잡종의 출현)

  • Kim, Chi-Hong;Lee, Wan-Ok;Kang, Yong-Jin;Baek, Jea-Min
    • Korean Journal of Ichthyology
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    • v.22 no.4
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    • pp.225-229
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    • 2010
  • A intergeneric hybrid between Rhodeus uyekii and Acheilognathus signifer was collected in the Jojongcheon Bukhan River. The hybrid showed intermediate characteristics of two parental types in some key characters, such as color pattern of body, pigmentation of dorsal, anal, and caudal fins, and body spot and stripe. In addition, the hybrid had a fairly large number of lateral line scales, while it lacked a barbel, which is known as a key intergeneric character. The probable occurrence of a natural hybrid is supported by a viable $F_1$ hybrid produced with the parental species.

Construction and Characterization of Escherichia coli-Corynebacterium nephridii Hybrid Thioredoxins

  • Sa, Jae-Hoon;Kim, Kyung-Hoon;Lim, Chang-Jin
    • BMB Reports
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    • v.28 no.1
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    • pp.51-56
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    • 1995
  • Thioredoxin is a small redox protein with an active-site disulfide/dithiol, and is ubiquitous in bacteria, plants, and animals. To investigate the structure-function relationship of thioredoxin, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3(N to C-terminal) and C3-E. The hybrid thioredoxin genes were put under the T7 promoter and their productions were confirmed. The two hybrid thioredoxins complemented phenotypes of a thioredoxin-deficient E. coli strain. A strain containing the C3-E hybrid thioredoxin supported growth of the T7 phage, whereas a strain expressing the E-C3 hybrid thioredoxin did not. However, both hybrids supported growth of M13 phages. The two hybrid thioredoxins were also characterized in other aspects. Differences in activity between the hybrid thioredoxins were attributed to altered interactions of the N- and C-terminal domains of the molecule, which produced changes in the three-dimensional structure of the active site region.

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Occurrence of Natural Hybrid between Oplegnathus fasciatus and Oplegnathus punctatus from the South Sea of Korea (한국 남해에서 출현한 돌돔 (Oplegnathus fasciatus)과 강담돔 (Oplegnathus punctatus) 사이의 자연교잡종)

  • Kwun, Hyuck-Joon;Kim, Jin-Koo
    • Korean Journal of Ichthyology
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    • v.22 no.3
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    • pp.201-205
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    • 2010
  • One specimen of a natural hybrid of an Oplegnathus (Oplegnathus fasciatus $\times$ Oplegnathus punctatus) was found in Tongyeong, Korea in August 2008. We, herein, describe its morphological and genetic characteristics and compare them with those of O. fasciatus and O. punctatus. In morphology, the hybrid showed many distinctive black rounded blotches on body sides and four faint vertical bars, being in those features similar to O. punctatus. Although the counts and measurements of the hybrid mostly overlapped between O. fasciatus and O. punctatus, the Oplegnathus hybrid resembled O. punctatus in the ratio of pelvic-fin length in standard length: Oplegnathus hybrid (26.7%) was closer to O. punctatus (26.4%) than to O. fasciatus (17.2~23.6%). In genetics, as a result of analysis of 510 base pair sequences of mitochondrial DNA 16S rRNA, the hybrid was closer to O. fasciatus (d=0.000~0.010) than to O. punctatus (d=0.020). Our results suggest that the natural hybridization represented by the subject specimen occurred between an O. fasciatus female and an O. punctatus male.

Effect of Fiber Orientation on Failure Strength Properties of Natural Fiber Reinforced Composites including Adhesive Bonded Joints (접착제 접합된 자연섬유강화 복합재료의 파괴 강도특성에 미치는 섬유방향의 영향)

  • Im, Jae-Gyu;Yun, Ho-Cheol;Lee, Sang-Yong;Renliang, Wang
    • Proceedings of the KWS Conference
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    • 2005.11a
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    • pp.94-96
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    • 2005
  • This paper is concerned with a fracture strength study of composite adhesive lap joints. The tensile and peel tests were carried out on specimen manufactured hybrid stacked composites such as the polyester and bamboo natural fiber layer. The main objective of the work was to test the failure strength of adhesive bonded joints using hybrid stacked composites with a polyester and bamboo natural fiber layer adjacent to the fiber orientation. From results, the load directional orientation, small amount and low thickness of bamboo natural fiber layer have a good effect on the tensile and peel strength of natural fiber reinforced composites. and these characters are have a great influence on fracture strength and failure shape of adhesive bonded joints using hybrid stacked composites in the difference of fiber orientation.

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A Natural Hybrid of Intergeneric Mating between a Female Pungtungia herzi and a Male Pseudorasbora parva (Cypriniformes: Cyprinidae)

  • Kim, Keun-Yong;Ko, Myeong-Hun;Cho, Sung Jang;Kim, Woo-Jin;Son, Min Ho;Bang, In-Chul
    • Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.99-107
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    • 2015
  • A natural hybrid of a probable intergeneric mating between the striped shiner Pungtungia herzi and the stone morocco Pseudorasbora parva (Cypriniformes: Cyprinidae) was captured in the Geumho River, a tributary of the Nakdong River basin in Korea. Morphological characters and DNA sequences were analyzed to verify its hybrid state and identify the parentage of its parent species. The hybrid exhibited a phenotypic intermediacy between the two parent species in the number of vertebrae and the mouth shape. Out of 1,488 base pair (bp) positions of the nuclear recombination activating gene 1 gene (rag1), which has a biparental mode of inheritance, 41-bp substitutions were detected between the two parent species, whereas an electropherogram of the hybrid displayed polymorphic double peaks at all of the base positions, along with one additional one, strongly indicating its hybrid state. Meanwhile, sequence comparison of the mitochondrial cytochrome b gene (mt-cyb) (1,140 bp), which has a maternal mode of inheritance, showed only 5-22-bp differences (97.6-99.5% identities) between the hybrid and Pu. herzi, but as many as 158-168-bp differences (85.2-86.1% identities) between the hybrid and Ps. parva, clearly indicating Pu. herzi as the maternal species. Thus, combined analyses of independent data sets (i.e., morphology and nuclear and mitochondrial DNA sequences) offered convincing evidence for the hybrid state of a naturally occurring hybrid resulting from intergeneric mating between a female Pu. herzi and a male Ps. parva.