• Title/Summary/Keyword: interlocking mechanism

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Study on Eum-yang Interlocking in "Hwangjenaegyeong(黃帝內經)" ("황제내경(黃帝內經)" "음양교(陰陽交)" 병해석(病解析))

  • Ju, Bao-Zhao;Kim, Hyo-Chul
    • Journal of Korean Medical classics
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    • v.23 no.4
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    • pp.31-33
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    • 2010
  • The earliest record of 'Eum-yang Interlocking(陰陽交)' is in "Hwangjenaegyeong(黃帝內經)". In this article, we reviewed the meaning of the two Chinese Characters 'On'(溫) and "Gyo"(交), discussed the meaning, mechanism and treatment principles of Eum-yang Interlocking and Three Incurable Symptoms in order to provide a theoretical basis for treating the warm febrile disease in modern times.

Frictional Behavior of Solid and Hollow Cylinders in Contact Against a Porcine Intestine Specimen

  • Kim, Young-Tae;Kim, Dae-Eun;Park, Suk-Ho;Yoon, Eui-Sung
    • KSTLE International Journal
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    • v.7 no.2
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    • pp.51-55
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    • 2006
  • In order to design an effective foot surface which can provide adequate friction for a self-propelled medical microrobot moving inside the small intestine, frictional mechanisms between the small intestine inner wall and the foot surface of the robot must be understood. In this paper, mechanical interlocking effect was considered to design the surface of the foot that can generate the desired frictional force. The concept of the design was derived from the hookworm that lives inside the small intestine. Hookwarms are known to adhere to the small intestine wall by interlocking with villi on the surface of the small intestine. The interlocking mechanism was considered as the main frictional mechanism for the design of the microrobot foot surface in this work. 2 mm and 6 mm diameter solid and hollow cylindrical shaped foot specimens were designed and tested to assess the frictional force between the specimens and the porcine small intestine specimen.

Understanding of Subsurface Cavity Mechanism due to the Deterioration of Buried Pipe (노후 매립관로로 인한 지하 공동발생 메카니즘 고찰)

  • Lee, Dae-Young;Cho, Nam-Kak
    • Journal of the Korean Geotechnical Society
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    • v.32 no.12
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    • pp.33-43
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    • 2016
  • In order to analyze ground relaxation and cavity formation mechanism due to deteriorated sewer pipe, field test was carried out and a numerical assessments were compared with the field test results. An artificial underground cavity was intended using the ice block overlaying the buried pipe and confirmed that the cavity and relaxation of the surrounding ground were gradually formed as the ice block starts to melt down. Such mechanism was highly suspected to be involved with soil particle interlocking as a soil compaction was a typical process for the buried pipes. In exploring such mechanism numerically, commercially available DEM (Discrete Element Method) code PFC2D was used and the interlocking induced cavern behaviors were successfully simulated and compared with field test results by utilizing the clump logic imbedded in PFC code.

Study on the Evolution of Sand Structure during Shearing (전단시험 중 모래입자의 변형에 관한 연구)

  • 이석원
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.289-296
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    • 2000
  • This paper summarizes the results of a study which has quantified the evolution of the structure of sands adjacent to geomembranes of varying roughness at different stages of shearing. The results show that the structure evolution, and hence shear mechanisms for rounded uniform sands adjacent to geomembranes, are directly influenced by the surface roughness of the geomembranes. For smooth geomembranes, the shear mechanism predominantly involves sliding of sand particles and only affects the sand structure within two particle diameters of the geomembrane. For slightly textured geomembranes, the effects of interlocking and dilation of sand particles extends the zone of evolution to four particles diameters from the interface. For moderately/heavily textured geomembranes, the interlocking and dilation of sand particles is fully developed and results in large dilation in the interfacial zone, which extends up to six particle diameters from the interface. By understanding how the structure of the sand adjacent to geomembranes of different roughness changes during shearing, it may be possible to identify alternative geomembrane roughening procedures and patterns that can lead to more efficient interface designs.

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Mechanism of Strength Development in Ultra High Strength Concrete Using the Electric Arc Furnace Oxidizing Slag as Fine Aggregate (초고강도 콘크리트에서 전기로 산화 슬래그 잔골재 사용에 의한 강도 증진 기구)

  • Lee, Seung-Heun;Lim, Doo-Sub;Lee, Seung-Hoon;Lee, Joo-Ha
    • Journal of the Korea Concrete Institute
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    • v.25 no.1
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    • pp.3-9
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    • 2013
  • In ultra high strength concrete, when electric arc furnace oxidizing slag is substituted for sea sand as fine aggregate, compressive strength was improved about 15 MPa. To figure out the cause of the improvement in compressive strength, this study considered the dissolution characteristics of Ca component in fine aggregate and examined the microstructure, porosity, microhardness, and Ca/Si mole ratio on the interface of fine aggregate and paste. And to examine the mechanism of strength improvement resulted from the shape of fine aggregate, this study measured the surface roughness of fine aggregate with AFM. According to the result of this experiment, the mechanisms of strength improvement in ultra high strength concrete resulted from the use of electric arc furnace oxidizing slag as fine aggregate can be divided into chemical and physical mechanisms. In the chemical mechanism, the soluble Ca component contained in electric arc furnace oxidizing slag is dissolved and forms a hydrate between fine aggregate and paste to improve the interlocking strength of fine aggregate-paste. Also, it makes the microstructure around the fine aggregate. And in the physical mechanism, electric arc furnace oxidizing slag has a twice greater surface roughness than sea sand, so the interlocking strength between fine aggregate and paste increases, which contributes to the development of compressive strength.

Discrete element modelling of geogrids with square and triangular apertures

  • Chen, Cheng;McDowell, Glenn;Rui, Rui
    • Geomechanics and Engineering
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    • v.16 no.5
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    • pp.495-501
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    • 2018
  • Geogrid application that has proved to be an effective and economic method of reinforcing particles, is widely used in geotechnical engineering. The discrete element method (DEM) has been used to investigate the micro mechanics of the geogrid deformation and also the interlocking mechanism that cannot be easily studies in laboratory tests. Two types of realistically shaped geogrid models with square and triangle apertures were developed using parallel bonds in PFC3D. The calibration test simulations have demonstrated that the precisely shaped triangular geogrid model is also able to reproduce the deformation and strength characteristics of geogrids. Moreover, the square and triangular geogrid models were also used in DEM pull-out test simulations with idealized shape particle models for validation. The simulation results have been shown to provide good predictions of pullout force as a function of displacement especially for the initial 30 mm displacement. For the granular material of size 40 mm, both the experimental and DEM results demonstrate that the triangular geogrid of size 75 mm outperforms the square geogrid of size 65 mm. Besides, the simulations have given valuable insight into the interaction between particle and geogrid and also revealed similar deformation behavior of geogrids during pullout. Therefore, the DEM provides a tool which enable to model other possible prototype geogrid and investigate their performance before manufacture.

Effect of Ni Bond Coat on Adhesive Properties of Fe Coating Thermal Sprayed on Al Substrate (Ni 본드코팅이 Al 기지에 고온 용사 코팅된 Fe 코팅층의 접합특성에 미치는 영향)

  • Kwon, Eui-Pyo;Kim, Dae-Young;Lee, Jong-Kweon
    • Korean Journal of Materials Research
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    • v.26 no.10
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    • pp.542-548
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    • 2016
  • The influence of NiCrAlY bond coating on the adhesion properties of an Fe thermal coating sprayed on an Al substrate was investigated. By applying a bond coat, an adhesion strength of 21MPa was obtained, which was higher than the 15.5MPa strength of the coating without the bond coat. Formation of cracks at the interface of the bond coat and the Al substrate was suppressed by applying the bond coat. Microstructural analysis of the coating interface using EBSD and TEM indicated that the dominant bonding mechanism was mechanical interlocking. Mechanical interlocking without crack defects in the coating interface may improve the adhesion strength of the coating. In conclusion, the use of an NiCrAlY bond coat is an effective method of improving the adhesion properties of thermal sprayed Fe coatings on Al substrates.

A Study on the Spring Design of Smooth Lifting System for Monitor (모니터용 유연 승강의 스프링 설계에 관한 연구)

  • Cheong, Seon-Hwan;Choi, Seong-Dae;Byun, Yong-Kun;Choi, Eun-Hwan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.4 no.4
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    • pp.48-53
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    • 2005
  • This research is materialized the mechanism of a interlocking elevator device to meet with customer's requirement demanding a variety of function. On this suitably theoretical translation and by considering of material significance of the most factor's tension spring and torsion spring, it's compared and reviewed the stress's calculation according that SWC and SWPB applied differently. And also that is approved through actual experiment. Out of a variety of feasible movement. Torque Balance is materialized by combination of tension spring, torsion spring and disk spring. So that application of 3 factors for optimal design is very important factor. In future, this research thesis make sure to play a highly role for application and improvement mechanically in various industry sector out of materializing interlock.

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Effect of Desmear Treatment on the Interfacial Bonding Mechanism of Electroless-Plated Cu film on FR-4 Substrate (Desmear 습식 표면 전처리가 무전해 도금된 Cu 박막과 FR-4 기판 사이의 계면 접착 기구에 미치는 영향)

  • Min, Kyoung-Jin;Park, Young-Bae
    • Korean Journal of Materials Research
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    • v.19 no.11
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    • pp.625-630
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    • 2009
  • Embedding of active devices in a printed circuit board has increasingly been adopted as a future electronic technology due to its promotion of high density, high speed and high performance. One responsible technology is to embedded active device into a dielectric substrate with a build-up process, for example a chipin-substrate (CiS) structure. In this study, desmear treatment was performed before Cu metallization on an FR-4 surface in order to improve interfacial adhesion between electroless-plated Cu and FR-4 substrate in Cu via structures in CiS systems. Surface analyses using atomic force microscopy and x-ray photoemission spectroscopy were systematically performed to understand the fundamental adhesion mechanism; results were correlated with peel strength measured by a 90o peel test. Interfacial bonding mechanism between electrolessplated Cu and FR-4 substrate seems to be dominated by a chemical bonding effect resulting from the selective activation of chemical bonding between carbon and oxygen through a rearrangement of C-C bonding rather than from a mechanical interlocking effect. In fact, desmear wet treatment could result in extensive degradation of FR-4 cohesive strength when compared to dry surface-treated Cu/FR-4 structures.

A Study on the Strength and Fracture Toughness of High Strength Hardened Cement Paste (고강도 시멘트 경화체의 강도 및 파괴인성에 관한 연구)

  • 김정환
    • Magazine of the Korea Concrete Institute
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    • v.6 no.6
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    • pp.151-158
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    • 1994
  • In this work, in order to inrprove the flexural strength of hardened portlarid cerncrit paste, mix ing water was reduced to water ccrnent ratio of 0.1 aid water soluble polymer such as hydroxy propyl methyl cellulose was adclelri to the paste to obtain a better dispersion. The paste was kneaded by the twin roll mill for cornpact and homogeneous mixing. The high strength mechanism of the hardened cement paste may be due to the removal of macropores larger than 100${\mu}m$, the reduction of capillary pores acting as the passage of crack propagation, the increase of Young's moculus with iticrease of unhytlratcci cenxxnt ard the incicasc of fracture toughnevs with the crack toughening mechanism (grain bridging, polymer fibril bridging and fritional inter-locking).