• 제목/요약/키워드: Pointed tip

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Microstructure of the biological attachment devices in the ladybug Harmonia axyridis (Coleoptera: Coccinellidae)

  • Moon, Myung-Jin;Kim, Hyo-Jeong;Kim, Hoon;Park, Jong-Gu
    • Animal cells and systems
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    • v.16 no.6
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    • pp.479-487
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    • 2012
  • Biological attachment device is optimized in insect legs for attachment onto the variety of natural substrate. We have studied the microstructural characteristics of the tarsal appendages in the ladybug Harmonia axyridis using scanning electron microscopy to reveal the attachment system of their legs. The attachment devices are composed of claws and adhesive pads. The claws are connected with pretarsal segment, and their apical diverged hooks are developed to hold rough substrates. In contrast, the adhesive pads have an adhesive function onto smooth surface. The pads are interspersed at the ventral part of each tarsomere, and are composed of two kinds of hairy setae. The discoid tip seta (DtS) has a spoon-shaped endplate usually with a rounded concave structure, whereas the pointed tip seta (PtS) has a pointed tip, usually with a hooked endplate. While the PtS is broadly localized concentrically on the marginal area of both the proximal and distal pads, the DtS can be seen at the central areas of each adhesive pad except for the hind legs. Our findings demonstrate the presence of the direction-dependence pattern of the fibrillar system as well as a functional modification of the tenent setae to achieve proper contact with almost any kind of substrates.

Numerical study on bearing behavior of pile considering sand particle crushing

  • Wu, Yang;Yamamoto, Haruyuki;Yao, Yangping
    • Geomechanics and Engineering
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    • v.5 no.3
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    • pp.241-261
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    • 2013
  • The bearing mechanism of pile during installation and loading process which controls the deformation and distribution of strain and stress in the soil surrounding pile tip is complex and full of much uncertainty. It is pointed out that particle crushing occurs in significant stress concentrated region such as the area surrounding pile tip. The solution to this problem requires the understanding and modeling of the mechanical behavior of granular soil under high pressures. This study aims to investigate the sand behavior around pile tip considering the characteristics of sand crushing. The numerical analysis of model pile loading test under different surcharge pressure with constitutive model for sand crushing is presented. This constitutive model is capable of predicting the dilatancy of soil from negative to positive under low confining pressure and only negative dilatancy under high confining pressure. The predicted relationships between the normalized bearing stress and normalized displacement are agreeable with the experimental results during the entire loading process. It is estimated from numerical results that the vertical stress beneath pile tip is up to 20 MPa which is large enough to cause sand to be crushed. The predicted distribution area of volumetric strain represents that the distributed area shaped wedge for volumetric contraction is beneath pile tip and distributed area for volumetric expansion is near the pile shaft. It is demonstrated that the finite element formulation incorporating a constitutive model for sand with crushing is capable of producing reasonable results for the pile loading problem.

MORPHOLOGY OF UROHYAL BONES OF PLEURONECTIDAE FISHES IN KOREAN WATERS (한국산 가자미과 어류의 미설골의 형태에 관하여)

  • KIM Yong Uk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.5 no.4
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    • pp.121-127
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    • 1972
  • The present paper deals with the results of the comparative morphology on the urohyal bones on the right-eye flounders, pleuronectidae fishes in Korean waters. The results obtained are as follows : 1. The position of the tip of sciatic part is quite different depending on the genera and species of the fishes. The sciatic part of the genera, Platichthys and Cleisthenes, is very short extending to the middle portion of the main part. In the fishes of Eopsetta and Tanakius, it is also very short extending to the anterior 1/3 of the distance from the tip of main part. The fishes of Verasper and Dexistes have a short sciatic part which extends toward the posterior 1/4 of the distance from the tip of main part. The fishes Of Limanda, Clidoderma, Glyptecephalus and Microstomus have a long sciatic part which extends as long as the main part. However, those of Kareius and Pleuronichthys have a very long sciatic part extending twice long as the main part. The tip of sciatic part of the fishes belonging to Eopsetta, Verasper, Limanda, Platichthys, Tanakius and Glyptocephalus is a truncate form. It is pointed upward in the fishes of Kareius, Pleuronichthys, Clidoderma and Microstomus, but pointed forward in Cleisthenes and Dexistes. 2. The size and form of the cardiac apophysis vary with the developmental grades of the urohyal bone. The fishes of Eopsetta, Verasper, Platichthys, Tanakius, Kareius and Dexistes possess relatively large apophyses and those of Pleuronichthys and Clidoderma have small apophyses. Intermediate size of the apophysis is found in the fishes of Limanda, Microstomus and Cleisthenes. A long and barlike apophysis is found in Glyptocephalus. Three kinds of the cardiac. apophysis are found in the fishes examined, i. e., lateral wing in Eopsette, Verasper, Limanda, Platichthys, Tanakius, Glyptocephalus, Kareius, Pleuronichthys and Clidoderma, pointed forward in Microstomus and Cleisthenes, and truncate with a well-developed inner ridge type in Dexistes. 3. The angle of the main part and sciatic part varies from 30 to 60 degrees in the fishes studied except for the fishes of Pleuronichthys, Clidoderma and Microstomus which show a semi-elliptical form.

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Effects of electrode tips on the weldability of galvannealed steel (Galvannealed steel의 점 용접성에 미치는 전극 팁의 영향)

  • 유병길;강춘식
    • Journal of Welding and Joining
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    • v.5 no.3
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    • pp.11-18
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    • 1987
  • Effects of electrode tips shapes of spot welding on the galvannealed steel have been studied, and the results obtained from this studies are as follows. 1) Expulsion had no effect on the shear strength of the specimen but been observed on the tensile strength of the specimen. 2) Effect of holding time after welding was neglegible when the spot welding supplies enough heat input. 3) Depending on the sopt welding tip shape it has different weldbility. It has better weldability in the order of pointed shape, truncated shape and dome shape. But the effect of coolind was just the opposite of the above order.

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Illustrations of the Nine Types of Needles based on Huangdi's Internal Classic Ling-shu

  • Kim, Hyo Jin;Lee, Kwang Ho;Yang, Gi Young
    • Journal of Acupuncture Research
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    • v.36 no.1
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    • pp.38-44
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    • 2019
  • Background: The phrase "Nine Needles" refers to the 9 types of acupuncture needles describing their shapes, sizes, and uses in Huangdi's Internal Classic Ling-shu. The aim of this study was to present 3D illustrations of the "Nine Types of Needles" based on Huangdi's Internal classic Ling-shu, taking into consideration the conformation and application of the Nine Needles. Methods: Sketches of the "Nine Needles" were based on references to those needles cited in Huangdi's Internal Classic Ling-shu, the Great Compendium of Acupuncture and Moxibustion, and the Golden Mirror of Medicine. The computer programs Creo 3.0, Keyshot 5, Adobe Photoshop CS5, and Adobe Illustrator CS5 were used for 3D modelling and visualization. Results: Based on a review of Huangdi's Internal Classic Ling-shu, illustrations of the Spade needle, Round-Pointed needle, Pressure needle, Sharp-Edged needle, Sword-Shaped needle, Round-Sharp needle, Fine needle, Long needle, and Large needle, 3D models were created. The Spade needle had a sharp, large head, the Round-Pointed needle had an egg-shaped tip, and the Pressure needle had a blunt head like a grain of millet. The Sharp-Edged needle had a sharp blade with a triangular edge for bloodletting. The Sword-Shaped needle resembled a sword. The Round-Sharp needle resembled a horse's tail. The Fine needle and the Long needle had sharp points and thin bodies. The Large needle had a cylindrical shaft and rounded tip. Conclusion: This study demonstrated that 3D illustrations could be generated for the Nine Needles according to the descriptions and figures provided in the ancient literature.

A Study on Temperature Rising near Fatigue Crack Tip at Cryogenic Temperature (극저온 환경에서의 피로균열 선단의 온도상승에 관한 연구)

  • ;Maekawa, I.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.1
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    • pp.79-86
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    • 1995
  • The structural materials for cryogenic technology have been recently developed to support the many modern large-scale application from superconducting magnets for nuclear fusion reactor, magnetic levitation railway to LNG tankers. However it is pointed out that quenching phenomenon is one of the serious problems for the integrity of these applications, which is mainly attributed to the rapid temperature rising in the material due to some extrinsic factors of structures. From the viewpoint of fracture mechanics, it is therefore very important to clarify the mechanism of temperature rising of structural material due to cyclic loading at cryogenic temperature. From this purpose, fatigue test was carried out for high manganese steel at liquid helium temperature(4.2K) using triangular stress waveform to identify both the mechanism of temperature rising near crack tip and the effect of loading stress waveform on temperature rising near crack tip and the effect of loading stress waveforms on temperature rising. As the results, two types of temperature rising, that is, regular and burst types were observed. And a periodical temperature rising corresponding to the stress waveforms was also found. The peaks of the temperature rising were recorded near both the maximum and the minimum values of the applied stress. The sudden temperature rises, which indicated the higher values than those of periodical temperature rises under the repetition of stress, were observed at the final region of crack growth. It was shown that the peak values of the temperature rising increased with stress intensity factor range.

The Alar Extension Graft for Retracted Ala (Alar Extension Graft를 이용한 콧방울뒤당김의 교정)

  • Kim, Hyun soo;Roh, Si Gyun
    • Archives of Plastic Surgery
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    • v.36 no.1
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    • pp.66-74
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    • 2009
  • Purpose: The importance of the deformities in alar - columellar complex has been underestimated in Asian ethnic groups for the last decades. Fortunately, with increasing familiarity of the open rhinoplasty techniques, the anatomic details of the nasal tip have been pointed up. Definitely, having an interest and demand for improving the sub - normal relationship between the alar rim and columella are indebted for such growing of knowledge about nasal tip anatomy. However, it is true that any single procedure is not settled as versatile and fully confident modality to correct the retracted notching of the alar rim. With this article, I should like to propose another useful option for treating retracted ala. Methods: The author has tried to correct alar rim retraction by means of: (1) Triangular onlay septal cartilage graft on the lower lateral cartilage with the medial end fixed to the anterior surface of the lateral crus(Alar extension graft), (2) Inserting lateral end of the alar extension graft to the vestibular skin pocket in the form of a finger - in - groove, (3) using the vestibular skin in the form of an advancement flap, and (4) using the soft shield graft to prevent possible visible step - off of the alar margin. Results: The author applied an alar extension graft to 16 patients in order to correct a retracted ala for the last 27 months (August, 2003 - October, 2005). The distances from alar rim to long axis of nostril were improved to be within 2 mm in all of the cases, and also the shape of the alar rim changed to a round form. Nostril asymmetry (6%) in one case, temporary palpable step - off (18%) in three cases, temporary visible step - off (6%) in one case, and temporary paresthesia of the tip (25%) in four cases were observed. Conclusion: The alar extension graft is simple and efficacious. It does not need donor sites other than the operative field, and its results are predictable. In particular, since it may give structural intensity to a weak lower lateral cartilage, it may be preferentially used for the correction of a retracted ala that arises from hypoplastic lower lateral cartilage. Moreover intensified lower lateral cartilage also improves the esthetic shape of lobule.

Report on new record of sea slug nudibranch species Cadlinella subornatissima (Gastropoda: Chromodorididae) from Korean waters

  • Jung, Daewui;Gazi, Mohiuddin;Park, Joong-Ki
    • The Korean Journal of Malacology
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    • v.30 no.4
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    • pp.433-435
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    • 2014
  • A chromodorid nudibranch species Cadlinella subornatissima Baba, 1996 (Gastropoda: Nudibranchia: Chromodorididae) is newly recorded from Korean water. In this report, detailed external morphology is provided with its colored illustrations. This species is morphologically distinguished from other congeneric species by the following characteristics: the tip of dorsal papillae is pointed with pink pigment; yellow dorsal marking on central dorsum without mantle margin. The Korean chromodorid nudibranchs are composed of 19 species of 10 genera, including Cadlinella subornatissima which is firstly reported in the present study.

New record of the snake eel Ophichthus asakusae (Ophichthidae: Anguilliformes) from Korea

  • Kim, Byung-Jik;Choi, Jung-Hwa;Chang, Dae-Soo;Cha, Hyung-Kee;Park, Jong-Hwa
    • Fisheries and Aquatic Sciences
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    • v.12 no.3
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    • pp.236-239
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    • 2009
  • We describe Ophichthus asakusae from Korea based on a single specimen (426.0 mm TL) collected from the southern sea off Jeju Island. The species is characterized by a pointed, hard, sponge-like tail tip without a caudal fin and 126-132 total vertebrae. We propose a new Korean name, "Je-ju-ba-da-baem" for the species.

A new species of the genus Robertgurneya (Copepoda: Harpacticoida: Miraciidae) from the East Sea of Korea

  • Hyun Woo Bang
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.590-603
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    • 2021
  • Benthic harpacticoids were collected from the East Sea of Korea. Specimen were identified as members of the genus Robertgurneya Apostolov & Marinov, 1988 based on the following characteristics: the fourth segment of antennule with aesthetasc, antenna with three-segmented exopod, shape of mandible, and P1-P4 armature formula. Robertgurneya donghaensis sp. nov. is morphologically most closely related to R. simulans (Norman & Scott T., 1905) and R. similis similis (Scott A., 1896). However, R. donghaensis is characterized by the rostrum with a pointed tip, caudal rami about as board as the length of its inner edge, the first segment of the P1 endopod much longer than entire exopod, and the P5 exopod with five setae in male. The genus Robertgurneya is reported from Korean waters for the first time.