• Title/Summary/Keyword: Hollow Body

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A Strength Analysis of a Hull Girder in a Rough Sea

  • Kim, Sa-Soo;Shin, Ku-Kyun;Son, Sung-Wan
    • Selected Papers of The Society of Naval Architects of Korea
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    • v.2 no.1
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    • pp.79-105
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    • 1994
  • A ship in waves is suffered from the various wave loads that comes from its motion throughout its life. Because these loads are dynamic, the analysis of a ship structure must be considered as the dynamic problem precisely. In the rationally-based design, the dynamic structural analysis is carried out using dynamic wave loads provided from the results of the ship motion calculation as a rigid body. This method is based on the linear theory assumed low wave height and small amplitude of motion. But at the rough sea condition, high wave height, compared with ship's depth, induce the large ship motion, so the ship section configuration under waterline is rapidly changed at each time. This results in a non-linear problem. Considering above situation in this paper, a strength analysis method is introduced for the hull girder among waves considering non-linear hydrodynamic forces. This paper evaluates the overall or primary level of the ship structural dynamic loading and dynamic response provided from the non-linear wave forces, and bottom flare impact forces by momentum slamming theory. For numerical calculation a ship is idealized as a hollow thin-walled box beam using thin walled beam theory and the finite element method is used. This method applied to a 40,000 ton double hull tanker and attention is paid to the influence of the response of the ship's speed, wave length and wave height compared with the linear strip theory.

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An Experimental Study of Nonlinear Viscoelastic Bushing Model for Axial Mode

  • Lee, Seong-Beom;Shin, Jung-Woog;Alan S. Wineman
    • Journal of Mechanical Science and Technology
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    • v.17 no.9
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    • pp.1324-1331
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    • 2003
  • A bushing is a device used in automotive suspension systems to cushion the force transmitted from the wheel to the frame of the vehicle. A bushing is essentially a hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer surface. The shaft is connected to the suspension and the sleeve is connected to the frame. The cylinder provides the cushion when it deforms due to relative motion between the shaft and sleeve. The relation between the force applied to the shaft or sleeve and its deformation is nonlinear and exhibits features of viscoelasticity. An explicit force-displacement relation has been introduced for multi-body dynamics simulations. The relation is expressed in terms of a force relaxation function and a method of determination by experiments on bushings has been developed. Solutions allow for comparison between the force-displacement behavior by experiments and that predicted by the proposed method. It is shown that the predictions by the proposed force-displacement relation are in very good agreement with the experimental results.

A Study of A Nonlinear Viscoelastic Model for Elastomeric Bushing in Automotive Suspension System (I) -Axial Mode- (차량현가장치용 일래스토메릭 부시으이 비선형점탄성 모델연구 (I) -축 방향 모드-)

  • 이성범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.154-161
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    • 1999
  • An elastomeric bushing is a device used in automotive suspension systems to cushion the force transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer suface. The relation between the force applied to the shaft or sleeve and their relative deformation is nolinear and exhibits features of viscoelasticity. Numerical solutions of the boundary value problem represent the exact bushing response for use in the method for determining the force relaxation function of the bushing. The new nonlinear viscoelastic bushing model, which is called Pipkin-Rogers model, is proposed and it is shown that the predictions of the proposed force-displacement relation are in very good agreement with the exact results. This new bushing model is thus very suitable for use in multi-body dynamics codes. The success of the present study for axial mode response suggests that the same approach be applied to other modes, such as torsional or radial modes.

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A literatural study on the cause, treatment, prescription of Hiccup (애역에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Lee, Jong-Neun;Kim, Byeong-tak
    • Journal of Haehwa Medicine
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    • v.5 no.1
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    • pp.215-231
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    • 1996
  • In the literatual study on the hiccup, the results were as follows; 1. Hiccup is usually named as Hae yek, Hyel yek, Yel yek. 2. The cause of hiccup are stomach cold, rising of stomach fire, stagnation of vital energy and stagnation of phlegm, yang deficiency of spleen and kideny, deficiency of stomach-yin, or mental disorder due to the stagnation of phlegm, dyspepsia, depressed vital energy. 3. The treatment of hiccup are dispel cold by warming the middle warmer due to stomach cold, expel the heat-evil to loose hollow-organ due to rising up of stomach yin, regulate vital energy and dissipate phlegm due to stagnation of vital energy and stagnation of phlegm, warm and recuperate both of spleen and kidney due to spleen and kidney yang deficiency, nourish the stomach to promote the production of body fluid due to deficiency of stomach yin. 4. The prescription of hiccup are frequently used Gamchogungangtang Gangwhalbujatang Leejungtang Guelpigungang-tang due to stomach cold, Sosihotang Daesihotang Sojaganggitang due to rising up of stomach fire, Sunbokdaejasuktang due to stagnation of vital energy an dstagnation of phlegm, Bojungikgitang Goakhwanganwyisan Samsoeum due to spleen and kidney yang deficiency, Jaeumganghawtang Daebohoan due to deficiency of stomach yin, Hwanglyenjuklyetang Leejintang Guelpitang due to the stagnation of phlegm, Daewhajungeum due to dyspepsia, Mokhwangjogisan due to depressed vital energy.

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Effect of Additive Composition on Flexural Strength of Cullet-Loess Tile Bodies (첨가제의 조성이 폐유리-점토 타일의 곡강도에 미치는 영향)

  • Lee, Young-Il;Eom, Jung-Hye;Kim, Young-Wook;Song, In-Hyuck
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.416-422
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    • 2013
  • Cullet-loess tile bodies are successfully fabricated using cullet, loess, hollow microspheres, and sintering additives (borosilicate glass frit, boric acid, or fumed silica) as starting materials. The effects of the additive composition and sintering temperature on the sintered density and flexural strength of the cullet-loess tile bodies are investigated. The sintered density of the cullet-loess tile bodies increases with an increase in the sintering temperature as a result of the enhanced densification of pore walls through the viscous flow of a liquid phase formed from the glass frit and sintering additives. The flexural strength of the cullet-loess tile bodies increases with increases in the sintering temperature and the cullet content in the starting composition. A maximal flexural strength of 40 MPa is obtained in cullet-loess tile bodies sintered with glass frit at $800^{\circ}C$ in air.

An Evaluation on the Properties of the Hardened Lightweight Cement Using the Polyethylene Tube (폴리에틸렌 튜브를 혼입한 경량 시멘트 경화체의 기초물성 평가)

  • Kim, Sae-Young;Jeon, Bong-Min;Kim, Hyo-Youl;Oh, Sang-Gyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.57-60
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    • 2006
  • This study proposes the physical properties of the hardened lightweight cement using the polyethylene tube and to make the fundamental data regarding a new lightweight concrete development. The aerated concrete is displaying various effects such as lightweight, insulation characteristic and it is coming to be widely applied the slab layer of apartment as an insulating material but currently the aerated concrete has many problems. Therefore, demonstrating similar property of former aerated concrete and improving the defects, developing new hardened cement is needed. In this study, we predict adopting possibility of hollow core polyethylene tube, as a material to make cement hardening containing a lot of void. So we changed the mixing ratio, a diameter and length of the polyethylene tube and improved the compressive strength and unit capacity weight of the lightweight cement hardening body. From the test results, we judge that the aerated concrete is a developmental possibility.

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Study of oriental medical science documentory records of hiccup and neuropsychiatric aspect of hiccup (액역(呃逆)에 관한 한방정신의학적 고찰(考察))

  • Shim, Tae-Kyung;Jung, In-Chul;Lee, Sang-Ryong
    • Journal of Haehwa Medicine
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    • v.18 no.1
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    • pp.49-66
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    • 2009
  • 1. Hiccup is usually named as Hae yek, Hyel yek, Yel yek. 2. The cause of hiccup are stomach cold, rising of stomach fire, stagnation of vital energy and stagnationof phlegm, yang deficiency of spleen and kideny, deficiency of stomach-yin, or mental disorder due to the stagnation of phlegm, dyspepsia, depressed vital energy. 3. Vicera and Bowels related with Hiccup are lung, spleen, stomach, and heart. 4. The treatment of hiccup are dispel cold by warming the middle warmer due to stomach cold, expel the heat-evil to loose hollow-organ due to rising up of stomach yin, regulate vital energy and dissipate phlegm due to stagnation of vital energy and stagnation of phlegm, warm and recuperate both of spleen and kidney due to spleen and kidney yang deficiency, nourish the stomach to promote the production of body fluid due to deficiency of stomach yin. 5. Regarding neuropsychiatric aspect of hiccup, qi movement disorder was the main mechanism of disease and qi depression was the main cause. The prescriptions for neuropsychiatric hiccup were Mokhwangjogisan Pyunjakjunghyangsan, Daegwakhyangsan, and Haeaedan.

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Production Processes of Porous Metals and Their Applications (다공질 금속의 제조와 응용)

  • Shim, Jae-Dong;Byun, Ji-Young
    • Korean Journal of Materials Research
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    • v.25 no.3
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    • pp.155-164
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    • 2015
  • Porous metals are called as a new material of 21th century because they show not only extremely low density, but also novel physical, thermal, mechanical, electrical, and acoustic properties. Since the late in the 1990's, considerable progress has been made in the production technologies of many kinds of porous metals such as aluminum, titanium, nickel, copper, stainless steel, etc. The commercial applications of porous metals have been increased in the field of light weight structures, sound absorption, mechanical damping, bio-materials, thermal management for heat exchanger and heat sink. Especially, the porous metals are promising in automotive applications for light-weighting body sheets and various structural components due to the good relation between weight and stiffness. This paper reviews the recent progress of production techniques using molten metal bubbling, metal foaming, gas expansion, hollow sphere structure, unidirectional solidification, etc, which have been commercialized or under developing, and finally introduces several case studies on the potential applications of porous metals in the area of heat sink, automotive pannel, cathod for Ni-MH battery, golf putter and medical implant.

Development of Hollow Fibers for the Controlled Release of Drugs

  • Feijen, J.;Eenink, M.J.D.;Olijslager, J.;Schakenraad, J.M.;Nieuwenhuis, P.;Molenaar, I.
    • Journal of Biomedical Engineering Research
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    • v.7 no.2
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    • pp.111-112
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    • 1986
  • Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise.

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A Study on Manufacturing Techniques and Conservation Treatment for Yongjam, Ceremonial Hairpin with a Dragon-shaped Engraving in 17th Century - Focusing on Yongjam of the Clothes Worn by Oejae Yi Dan-ha and His wife, National Folklore Cultural Heritage No.4 - (17세기 대례용 용잠의 제작기법 조사와 보존처리 - 국가민속문화재 제4호 외재 이단하 내외옷 용잠을 중심으로 -)

  • Ryu, Dongwan;An, Boyeon;Lee, Ryangmi;Lee, Jaesung;Park, Yeonghwan;You, Harim
    • Journal of Conservation Science
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    • v.37 no.3
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    • pp.270-281
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    • 2021
  • The Yongjam of Oejae, Yi Dan-ha's wife, is an ornamental hairpin with a dragon-shaped engraving; designated as National Folklore Cultural Heritage No. 4. It is also a component of the ceremonial costume, and an artifact of great value as it clearly identifies the position of the wearer and the period of this artifact. The Yongjam has been well preserved in general; however, various pollutants and corrosive products have affected the engraved patterns, requiring conservation treatment. Furthermore, a non-destructive analysis was conducted to identify the components of the materials and the manufacturing techniques used in the ornament. The Yongjam is hollow inside to reduce its weight when placed in the hair and has a color contrast of gold, red, and black. The decorative part and the body were made separately. That is, the body was made from an alloy of copper, silver, and zinc, and its joint was elaborately connected without any overlaps. In the decorative part, different alloy ratios were identified in the dragon's face, beard, horn, body, and fin. Further, for the dragon's face with its delicate patterns, an alloy of silver and copper was used, likely to make the face appear as realistic as possible.