• 제목/요약/키워드: Anchoring effects

검색결과 67건 처리시간 0.029초

Root proximity of the anchoring miniscrews of orthodontic miniplates in the mandibular incisal area: Cone-beam computed tomographic analysis

  • Jeong, Do-Min;Oh, Song Hee;Choo, HyeRan;Choi, Yong-Suk;Kim, Seong-Hun;Lee, Jin-Suk;Hwang, Eui-Hwan
    • 대한치과교정학회지
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    • 제51권4호
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    • pp.231-240
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    • 2021
  • Objective: This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area. Methods: Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses. Results: The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area. Conclusions: Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1-MPASs to be placed in the no-root area.

탄소섬유 Rod로 성능향상된 R/C보의 휨 거동 연구 (The Study on Flexural Behavior of Reinforced Concrete Beams Strengthened with the Carbon Fiber Rod)

  • 심종성;문도영;김영호;김동희
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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    • pp.611-616
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    • 2002
  • The concrete beam is quickly required to be replaced or strengthened due to decreasing load carrying capacity. Flexural tests on 3.1m long reinforced concrete beams with carbon-fiber rod are reported. The selected experimental variable is the method of the anchoring beam. The effects of this variable in overall behavior are discussed. This paper considered relation of load-displacement and load-strain. The maximum load was increased to the static behavior of the R/C beam strengthened with CFR rod. The results indicated generally that the flexural strength of strengthening beam was increased. It was required a proper anchorage system and can be led the ductility of beams of a carbon-fiber rod.

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Effect of nonionic surfactants on the electrorheology of emulsions

  • Ha, Jong-Wook;Moon, Jung-Hyuk;Yang, Seung-Man
    • Korea-Australia Rheology Journal
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    • 제11권3호
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    • pp.241-246
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    • 1999
  • In this study, we consider the effect of nonionic surfactants on the rheological responses of emulsion systems under the action of a uniform do electric field. The model emulsions consist of a less conducting dispersed phase and a more conducting continuous phase. When the shear flow is weak, the positive viscosity effect is produced due to the formation of chain-like morphology. The nonionic surfactants used here generate two distinctively different effects. Specifically, first, the steric hindrance induced by the surfactant molecules renders the structure unstable, and thereby reduces the degree of positive viscosity effect. Secondly, the presence of surfactant molecules also prevents the rotation of the dispersed droplets by anchoring across the interface or by decreasing the size of dispersed phase. The second effect suppresses the negative viscosity effect.

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배향막의 극성이 a-TN-LCD의 전기광학특성에 미치는 효과 (Effects of Polarity of the Orientation Film for Electro-optical Characteristics on a-TN-LCD)

  • 서대식;이창훈;이보호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.27-30
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    • 1997
  • We investigated the electro-optical characteristics of amorphous (a) - twisted nematic (TN) - liquid crystal display (LCD) on polyimide (Pl) films with different polarity. It was found that the threshold voltage of a-TN-LCD is decreased with increasing the polarity of the Pl film. We considered that the threshold voltage in a-TN-LCD is affected to the surface anchoring strength with polarity of the Pl films. Also, we observed the response time of a-TN-LCD on medium polarity of the Pl film is fast compared to high polarity of the Pl film. Finally, we obtained that the viewing angle of a-TN-LCD are almost same on different polarity of the PI films.

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슬래브교 네트형 외부강선 보강 공법의 실험적 연구 (A Study of Net Type External Prestress Strengthening Method for Slab Bridges)

  • 한만엽;신재우;강태헌;진경석;강상훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.266-269
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    • 2006
  • External pre-stressing strengthening method is the most popular way to strengthen concrete structures because of its efficiency and economic advantage. The laboratory test was performed to reinforce the slave bridge with the external tendon strengthening by longitudinally and transversally, which is concerned with formal feature of slave bridge, generally. Based on this test, anchoring device to strengthen the external tendon strengthening method was established and its strengthening effects were verified by evaluating the load bearing capacity.

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실험시장접근법을 이용한 먹는 물 수질개선에 대한 지불의사 측정 (Valuing Drinking Water Risk Reductions Using Experimental Market Method)

  • 엄영숙
    • 자원ㆍ환경경제연구
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    • 제9권4호
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    • pp.747-771
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    • 2000
  • This paper reports the results of a study to elicit willingness to pay (WTP) for changes in health risks from exposure to As, Pb, THM in tap water using experimental market method. The experimental market method, compared with other non-market valuation methods, allows us to use incentive compatible demand revealing scheme, to acquire market-like experience through repetitive auctions, and to incorporate learning process by providing new information during the session. Participants seemed to utilize the objective risk information in a 'rational' manner, and to change their WTP bids accordingly. Moreover they were able to reduce the 'ambiguity' in risk perception processes when objective risk probabilities provided are quite different from their subjective perceptions. Nonetheless, anchoring effects appeared to be still persistent in spite of market-like experience and learning opportunity. And implicit values entailed by WTP bid/risk tradeoffs indicate a wide variation in values across alternative risk reductions and overrated responses to very small risk reductions.

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Effects of concrete strength on structural behavior of holed-incrementally prestressed concrete (H-IPC) girder

  • Han, Man Yop;Kim, Sung Bo;Kang, Tae Heon
    • Advances in concrete construction
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    • 제3권2호
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    • pp.113-126
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    • 2015
  • Holed-Incrementally Prestressed Concrete (H-IPC) girders are designed using the following new design concepts. At first, web openings reduce the self-weight of the girder, and also diffuse prestressing tendon anchorages. The reduced end anchoring forces decrease the web thickness of the end sections. Additionally, precast technology help to improve the quality of concrete and to reduce the construction period at the site. For experimentally verification, two 50 m full-scale H-IPC girders are manufactured with different concrete strength of 55 MPa and 80 MPa. The safety, stiffness, ductility, serviceability and crack development of H-IPC girder are measured and compared with each other for different strengths. Both girders show enough strength to carry live load and good stiffness to satisfy the design criteria. The experimental result shows the advantages of using high strength concrete and adopting precast girder. The test data can be used as a criterion for safety control and maintenance of the H-IPC girder.

a-TN-LCD의 전기광학특성에 미치는 액정배향의 효과 (Effects of Liquid Crystal Alignment on the Electro-Optical Characteristics of a-TN-LCD)

  • 서대식;이창훈;황율연;이보호;이승희;김향율
    • E2M - 전기 전자와 첨단 소재
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    • 제10권1호
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    • pp.15-19
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    • 1997
  • The characteristics of the response time and the viewing angle on twisted nematic (TN) liquid crystal display (LCD) and amorphous (a)-TN-LCD without rubbing were investigated. To measure the tansmission-voltage, response time, and viewing angle characteristics, we prepared three kinds of LC cells and then studied the surface liquid crystal alignment effect. It was found that the response time on A-TN-LCD was fast compared to the TN-I-CD, and the weak anchoring strength was attributed to the fast response time on a-TN-LCD. Also, we obtained the wide viewing angle characteristics on a-TN-LCD. The liquid crystal alignment of LCD device for electro-optical characteristics is discussed in the present paper.

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표면전처리가 반응성 스퍼터링법으로 제조한 TiN 코팅층의 밀착력에 미치는 영향 (The Effects of Surface Pretreatments on Adhesion Strength of TiN Films by DC Magnetron Sputtering)

  • 김흥윤;백운승;권식철;김규호
    • 한국표면공학회지
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    • 제26권5호
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    • pp.225-234
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    • 1993
  • Titanium nitride coatings were deposited onto SUS304 stainless steel substrates pretreated by mechanical scrubbing, chemical etching at 50% HCl solution and Ar ion etching. Adhesion strength were measured by scratch tester and confirmed by SEM with EDS. Adhesion strength of Ar ion etched substrate was 10 to 15 times higher than that of mechanical scrubbed or chemical etched substrate. Ar ion etching brought about an uniform and fine spherical shaped surface, while chemical etching gave rise to a rough and irregular surface on SEM micrograph. It was suggested that higher adhesion strength might be caused by anchoring effect of Ar ion etched surface prior to TiN deposition.

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Inhibitory Effects of Streptomyces sp. MBTH32 Metabolites on Sortase A and Sortase A-Mediated Cell Clumping of Staphylococcus aureus to Fibrinogen

  • Chung, Beomkoo;Kwon, Oh-Seok;Shin, Jongheon;Oh, Ki-Bong
    • Journal of Microbiology and Biotechnology
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    • 제29권10호
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    • pp.1603-1606
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    • 2019
  • Sortase A (SrtA), a type of transpeptidase responsible for anchoring surface proteins to the peptidoglycan cell wall, is important in the virulence of gram-positive bacteria. Three compounds were isolated from marine-derived Streptomyces sp. MBTH32 using various chromatography techniques. The structures of these compounds were determined based on spectroscopic data and comparisons with previously reported data. Among the metabolites tested, lumichrome showed strong inhibitory activity against Staphylococcus aureus SrtA without affecting cell viability. The results of cell clumping activity assessment suggest the potential for using this compound to treat S. aureus infection by inhibiting SrtA activity.