• Title/Summary/Keyword: C-hook

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A new approach for the cylindrical cavity expansion problem incorporating deformation dependent of intermediate principal stress

  • Zou, Jin-Feng;Xia, Ming-yao
    • Geomechanics and Engineering
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    • v.12 no.3
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    • pp.347-360
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    • 2017
  • The problem of cylindrical cavity expansion incorporating deformation dependent of intermediate principal stress in rock or soil mass is investigated in the paper. Assumptions that the initial axial total strain is a non-zero constant and the axial plastic strain is not zero are defined to obtain the numerical solution of strain which incorporates deformation-dependent intermediate principal stress. The numerical solution of plastic strains are achieved by the 3-D plastic potential functions based on the M-C and generalized H-B failure criteria, respectively. The intermediate principal stress is derived with the Hook's law and plastic strains. Solution of limited expansion pressure, stress and strain during cylindrical cavity expanding are given and the corresponding calculation approaches are also presented, which the axial stress and strain are incorporated. Validation of the proposed approach is conducted by the published results.

An Unrecorded Naturalized Plant in Korea : Cakile edentula (Brassicaceae) (미기록 귀화식물: Cakile edentula (Brassicaceae))

  • Kil, Ji-Hyon;Lee, Kyu Song
    • Korean Journal of Plant Taxonomy
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    • v.38 no.2
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    • pp.179-185
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    • 2008
  • Unrecorded species from the beach at Gangnung City is reported: Cakile edentula, Brassicaceae. The genus Cakile is unrecorded in Korea and easily distinguished from other genera in Brassicaceae by the upper member of fruits distinctly longer or thicker than the lower part, petiole white or anthocyanic, style absent and leaves glabrous. The local name is Seo-yang-gaet-naeng-i and the morphological characters and illustrations of the species are provided.

Control of Semi-Active Suspensions for Commercial Vehicles (상용 차량용 반능동 현가 시스템의 제어)

  • Yi, K.;Jung, J.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.98-106
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    • 1998
  • In this study a control law and performance potential of semi-active suspensions for a tractor/semi-trailer have been investigated. The control law for airbag semi-active suspensions modeled in this study is developed using feedback linearization and Linear Quadratic (LQ) optimal control method. Inherent nonlinearity of the airbag suspensions has been considered in the control law development. It has been shown that the proposed semi-active control law provides better performance than that of well known sky-hook damping control strategy.

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New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea

  • Yang, Hee-Min;Min, Gi-Sik
    • Journal of Species Research
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    • v.11 no.3
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    • pp.174-179
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    • 2022
  • In this study, we identified two marine synchaetid rotifers, Synchaeta grimpei Remane, 1929 and S. vorax Rousselet, 1902, in Korea, which are the first synchaetid rotifers collected from a marine environment in the country. Prior to this study, all six synchaetids recorded in Korea were collected from freshwater environments. The morphological characteristics of both species are consistent with those recorded in previous studies of each species. Synchaeta grimpei is distinguished from other synchaetid rotifers by its cone-shaped body, wide and flat apical field, indistinct auricles, and long foot with two separated small toes. The morphological characteristics of Korean S. vorax specimens were most similar to the original description of Rousselet (1902), with its slender and cylindrical trunk shape, strongly convex apical field, and short foot with two small, separated toes. The rami of the Korean S. vorax specimen contained one frontal hook and several distinct and large teeth. Here, we provide the morphological diagnoses of the two synchaetid rotifers and the sequences of the partial mitochondrial cytochrome c oxidase subunit I (COI) of the two species.

Triptolide Suppresses the Expression of Cyclooxygenase-2 Induced by Toll-Like Receptor 3 and 4 Agonists

  • Gu, Gyo-Jeong;Eom, Sang-Hoon;Min, In Soon;Youn, Hyung-Sun
    • Biomedical Science Letters
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    • v.19 no.2
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    • pp.112-117
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    • 2013
  • Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2). Triptolide (TP), a natural component of Tripterygium wilfordii Hook. F, has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that TP inhibits the NF-${\kappa}B$ activation induced by polyriboinosinic polyribocytidylic acid (Poly[I:C], TLR3 agonist) and lipopolysaccharide (LPS, TLR4 agonist). TP also inhibits COX-2 expression induced by Poly[I:C] and LPS. These results suggest that TP can modulate the immune responses regulated by TLR3 and TLR4 signaling pathways.

Glochidial attachment and cyst formation on the fish (석패과 유생의 어체부착과 어류의 피낭형성)

  • Song, Ho-Bok;Kwon, Oh-Kil
    • Korean Journal of Ichthyology
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    • v.6 no.1
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    • pp.51-59
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    • 1994
  • Morphology of glochidia of two species of Unionidae mussels, Unio douglasiae and Anodonta woodiana were studied based on SEM, and their attachment on Acheilognathus yamatsutae(Acheilognathinae) was observed in the experimentally infected fishes. The glochidia were round-triangle in shape and possessed larval threads, hooks, hooklets, and sensory hairs. Glochidal attachment and cyst formation of the fish were observed without regard to feeding habit and habitat. Density of glochida on the fish (Acheilognathus yamatsutae) was in the order of pectoral fin, dorsal fin, gill and caudal fin. The host fish became encysted about 5-10 hours to the glochidia, and the glochidia detached about 5-6 days after attachment at water temperature $26{\pm}1^{\circ}C$.

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Comparative Tooth Morphology and Qualitative Analysis on the Enamel Surface using Energy Dispersive X-ray Spectroscopy in the White-Toothed Shrew Crocidura lasiura and C. suaveolens and the Red-Toothed Shrew Sorex caecutiens from Korea (한국 땃쥐속 우수리땃쥐 Crocidura lasiura와 작은땃쥐 C. suaveolens, 뒤쥐속 뒤쥐 Sorex caecutiens의 치아형태와 Energy Dispersive X-ray Spectroscopy를 이용한 법랑질 표면의 정성적 분석 비교)

  • Jeong, Soon-Jeong
    • Journal of dental hygiene science
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    • v.13 no.2
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    • pp.203-212
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    • 2013
  • The tooth morphology and qualitative mineral contents on enamel surface using energy dispersive X-ray spectroscopy, (EDX) were examined in the white-toothed shrew (genus Crocidura ) Crocidura lasiura and C. suaveolens and the red-toothed shrew (genus Sorex) Sorex caecutiens. In the case of C. lasiura and C. suaveolens, dental formula was found I 3/1 C1/1 P1/1 M3/3=28. The upper 1st and 2nd molars had an unequal W-shape formed by 5 cusps on the crown. The 3rd molar was found one-third the size of those of 1st and 2nd molars. The upper 1st incisor had two different sized hook-shapes and the lower 1st incisor was even. In the case of S. caecutiens, dental formula was found to be I3/1 C1/1 P3/1 M3/3=32. The upper 1st and 2nd molars had an equal W-shape on crown. The upper 3rd molar was half the size of those of the other molars. The upper 1st incisor possessed two similar sized hook-shapes and the lower 1st incisor had an uneven and serrated form. A comparison with the dental and cranial measurements revealed C. lasiura to be the largest of the three species (p<0.001) and C. suaveolens and S. caecutiens were similar in size (p>0.05). A qualitative analysis of mineral contents on enamel surface of the lower 1st incisor and lower 1st molar using EDX revealed C, O, P, Ca and Cu in all specimens and Pb was detected in several enamel specimens. No significant differences in the mineral contents (% weight) were observed among the three species (p>0.05). Fe was only detected on enamel surface of S. caecutiens with red pigmented teeth. Therefore, Fe is responsible for the red tip of the teeth. These results suggest that tooth morphological characteristics including the color of the tooth tip might be used as the key classifying species belonging to Crocidura and Sorex.

Field and Culture Studies on the Growth and Reproduction of Campylaephora hypnaeoides (석묵 (Campylaephora hypnaeoides)의 생장과 성숙에 대한 야외 및 배양 연구)

  • Yoo, Hyun-Il;Kim, Ji-Hwan;Choi, Han-Gil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.3
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    • pp.290-297
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    • 2011
  • The phenology of Campylaephora hypnaeoides J. Agardh and optimal conditions for carpospore release, growth and reproduction were examined in the field and in the laboratory from January to December 2007. In the field population of C. hypnaeoides, approximately 50% of the plants were vegetative during the study period. Additionally, the percentages of carposporophytes and tetrasporophytes were maximal in April (37%) and June (57%), respectively. Maximum growth in plant length, dry weight, and hook number coincided with the tetrasporophyte reproductive peak in the field. In culture, carpospore release, sporeling growth and reproduction were affected by environmental factors such as daylength, temperature, and salinity. The liberation of carpospores was maximum under continuous light and at a combination of $15^{\circ}C$ and $10\;{\mu}mol$ photons $m^{-2}\;s^{-1}$. Maximum growth of tetrasporophyte sporelings occurred at a combination of $20\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and $25^{\circ}C$. However, the growth of gametophyte sporelings was maximal under $40\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and in a combination of $20^{\circ}C$ and 35 psu. The tetrasporophyte sporelings were grew faster than gametophytes, indicating that gametophyte- and tetrasporophyte-sporelings have different physiological responses to irradiance and temperature. Tetrasporangial branches and cystocarps of C. hypnaeoides were produced from carpospores and tetraspores within 1 month, and they were stimulated at high temperature and irradiance levels. In conclusion, C. hypnaeoides should be seeded using carpospores during early winter (November-December) because cystocarps are easily identified by fishermen, and tetrasporophytes grow faster than gametophytes.

Growth and Morphological Charactersistics of Soybean Sprouts Treated with Leaf Extracts of Thea sinensis L. and Eucommia ulmoides Oliver (녹차와 두충 잎 추출물 처리에 따른 콩나물의 생장 및 형태적 특징)

  • Kang, Jin-Ho;Park, Cheol-Jong;Yoon, Soo-Young;Jeon, Seung-Ho;Her, Chang-Young
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.1
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    • pp.11-16
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    • 2005
  • Soybean sprouts presoaked to leaf extracts were on sale as taking a growing concern about wellbeing foods. The study was carried out to compare the effects of culture period after presoaking tea (Thea sinensis L.) and hard rubber tree (Eucommia ulmoides Oliver) leaf extracts on lateral root formation, growth and morphological characters of the sprouts. Seeds of three cultivars, Pungsannamulkong, Sowonkong and Junjery, were imbibed for 5 hours into 10% solutions immediately before 5, 6 and 7 day cultures. The cultured sprouts were classified into 4 categories to calculate their composition rates on the base of hypocotyllengths; >7 cm (A),4 to 7 cm (B),< 4 cm (C) and not germinated (D), and their morphological characters, fresh and dry weights were measured. Rate of A was the lowest in Junjery of the three cultivars, while that of C showed reverse result compared to A. Similar results to that of A were observed between the three cultivars in sprout length including hypocotyl and root, diameters in middle and hook parts of hypocotyl, total fresh and dry weights. Regardless of tea and hard rubber tree leaf extract treatments, longer culture periods increased rate of A due to decrements of B, C and D, and also did the growth and the morphological characters mentioned above. Although longer culture periods reduced the increment of lateral roots, the latter treatment was more delayed in their formation and less in the roots per sprout than the former one. The growth and the morphological characters above were less in the latter treatment than in the former one in general, meaning that hard rubber tree leaf extract could more repress growth of soybean sprouts than tea leaf extract.

Unrecorded fern species from Korean flora : Ctenitis maximowicziana, Dryopteris lunanensis and D. decipiens var. diplazioides (Dryopteridaceae) (한국산 미기록 양치식물 : 흰비늘고사리, 남도톱지네고사리, 애기지네고사리 (관중과))

  • Kim, Chul Hwan;Sun, Byung-Yun;Kim, Yong Bok
    • Korean Journal of Plant Taxonomy
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    • v.34 no.1
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    • pp.27-35
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    • 2004
  • Three unrecorded fern species from the flora of Korea belonging to family Dryopteridaceae, Ctenitis maximowicziana, Dryopteris lunanensis, and D. dcipiens var. diplazioides, are found along the valley of Mt. Wolgak (alt. 275m) in Gwangju, Korea. C. maximawicziana is well distinguished from the rest of the species in the genus including C. sinii by the color and morphology of scales in basal part of petioles, shape of blades, and the presence of round-reniform shaped indusia. Dryopteris lunanensis is also well distinguished from its close relative, D. atrata, by the number of lateral pinnae, degree of division of first and/or second pinnules in lower pinnae of the blades, and distribution pattern of sori. Dryapteris decipiens var. diplazioides is distinguishable from type variety by degree of division in lower pinnae of the blades. In terms of morphology, var. diplazioides seems to be intermediate between a type variety and D. fuscipes.