• Title/Summary/Keyword: adhesion amount

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ORIGINAL ARTICLE - Adhesion of Streptococcus mutans and Streptococcus sobrinus to different types of self-ligating brackets

  • Yang, Pil-Seung;Yu, Yoon-Jeong;Cha, Jung-Yul;Hwang, Chung-Ju
    • The Journal of the Korean dental association
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    • v.50 no.7
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    • pp.394-406
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    • 2012
  • Objective: The adhesion capabilities of different types of self-ligating brackets were measured with respect to Streptococcus mutans and Streptococcus sobrinus. Methods: Five types of self-ligating brackets (Clippy-C; Mini Clippy; Clarity-SL; Speed; Damon 3) were used for the experiment group and composite resin brackets (Spirit-MB), metal brackets (Victory) and polycrystalline alumina brackets (Clarity) were used for the control group. In order to assess adhesion of bacteria to the brackets, the brackets were cultured for 3, 6 and 24 hours in media containing bacteria and 20% sucrose. Results: There was no statistic difference in adhesion amount of Streptococcus mutans and Streptococcus sobrinus according to the types of brackets. A total adhesion amount according to bracket type was different. An extended incubation time increased adhesion amount. Observation under scanning electron microscope showed that Streptococcus sobrinus adhered more to Clippy-C and Victory rather than to Clarity-SL. Conclusions: Clarity-SL, a self-ligating esthetic bracket was confirmed to show lower bacterial adhesion to cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus group than other self-ligating brackets or conventional brackets, which suggests that proper use of self-ligating esthetic brackets might even be better in preventing tooth surface decalcification.

Adhesion Amount of Acetamipride on Plant and the Pest Control Effect According to the Reduced Application Amount (살포량 감소에 의한 살충제 Acetamipride의 작물 부착량과 나방류 방제효과)

  • Kim, Young-Shin;Jang, Ji-Woong;Jin, Na-Young;Yu, Yong-Man;Youn, Young-Nam;Lim, Chi-Hwan
    • The Korean Journal of Pesticide Science
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    • v.19 no.3
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    • pp.317-322
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    • 2015
  • This study was conducted to obtain basic data for deriving the appropriate application amount of insecticide for effective pest control. We have investigated the correlation among the application amount of insecticide, the adhesion amount of active ingredient and the pest control effect. The linear standard curve of acetamiprid was $R^2=0.9994$, and the scope of the recovery factor was between 71% and 93% with less than 6% of the coefficient of variation. During the test conducted in 2015, the application amount was reduced to 302 L/10a which was 70 L less than the previous year and the spraying pressure was reduced as well. After analyzing the adhesion amount of active ingredient, it was found that a correlation coefficient of adhesion amount of the active ingredients became lower from 82% to 69%, that indicated insecticide liquid was evenly distributed compared to 2014. Also more than 95% of control effect was displayed, thereby indicating that there is a close relation with the correlation coefficient of the adhesion amount of active ingredient. It also presented that the adhesion amount of active ingredient on the ground was 2.2 times more than that on the leaves of apple trees.

Adhesion of Soil to Polyester Fabric According to Polarity of Oily Soil in Oily/Particulate Mixed Soil System (지용성/고형오구의 혼합오염 계에서 지용성오구의 극성에 따른 Polyester직물에의 오구부착)

  • Kang, In-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.7
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    • pp.1175-1183
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    • 2010
  • This study investigates the effect of polarity of oily soil on adhesion of oily and particulate soil to PET fabric in oily/particulate mixed soil systems. The potential energy of interaction between two particles was examined as a fundamental environment of adhesion of soil to fabrics. The ${\zeta}$-potential of ${\alpha}-Fe_2O_3$ particles was measured by a microelectrophoresis method, and the potential energy of interaction between two particles was calculated by using the Verwey-Overbeek theory. The ${\zeta}$-potential of particle and the potential energy of interaction between two particles was slightly influenced by the polarity and type of oily soil, but increased with the increased anionic surfactant concentration and amount of oily soil. The adhesion of oily soil to fabric increased with the additional amount of polarity of oily soil and decreased surfactant concentration that was relatively high at a temperature of $60^{\circ}C$ surfactants solution. The adhesion of ${\alpha}-Fe_2O_3$ particle to PET fabric decreased with an increased amount and polarity of oily soil and increased surfactant concentration Although some similarity exists, the general trend of the adhesion to fabric by particulate soil differ from oily soil.

Synthesis and PSA Properties of Acryl Modified Resin for Semiconductor Wafer (반도체 웨이퍼용 아크릴 변성 수지의 합성 및 점착 특성)

  • Sim, Jong Bae;Shin, Kyoung Sub;Hwang, Taek Sung
    • Journal of Adhesion and Interface
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    • v.11 no.2
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    • pp.63-69
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    • 2010
  • In this study, acryl resin PSA containing hydroxyl group based on 2-EHA (2-ethyl hexyl acrylate), 2-EHMA (2-ethyl hexyl methacrylate), 2-HEA (2-Hydroxy ethyl acrylate), acrylic acid was synthesized and then, isocyanate modified acryl resin PSA prepared with adduct reaction according to the amount of MOI (Methacryloyloxyethyl isocyanate) or 2-isocyanatoethyl methacrylate that can improve the curing property. This research shows that the initial PSA and peel adhesion are decreased according to the increase of the amount of the MOI and isocyanate curing agent. After UV irradiating, the peel adhesion is decreased with increasing the amount of the MOI (Methacryloyloxyethyl isocyanate) and isocyanate curing agent, because of the high curing property.

Influence of plant surface spray adhesion of dinotefuran and thiodicarb on control of apple leafminer

  • Kim, Young-Shin;Kim, Kwang-Soo;Jin, Na-Young;Yu, Yong-Man;Youn, Young-Nam;Lim, Chi-Hwan
    • Korean Journal of Agricultural Science
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    • v.43 no.3
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    • pp.346-352
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    • 2016
  • This study was conducted to obtain the correlation between the plant surface spray adhesion amount of pesticides and the pest control effect. The linearity of the standard curves of dinotefuran and thiodicarb was $R^2=0.9999$, and recovery was between 70% to 120% which was satisfactory for insecticide residue analyses. The pest control effect was evaluated by assessing the number of apple leafminers (Phyllonorycter ringoniella, Gracillariidae, Lepidoptera) captured by sex pheromone traps from late June to late September in 2015. For the adhesion amount, dinotefuran recovered from trap A and B, respectively were $47{\mu}g/50cm^2$ and $23{\mu}g/50cm^2$, which can be characterized as a very low adhesion amount in comparison to the average adhesion amount of $81{\mu}g/50cm^2$ in the field. In case of thiodicarb, $691{\mu}g/50cm^2$ and $71{\mu}g/50cm^2$ were recovered from trap A and B, respectively, and the average amount in the field is $325{\mu}g/50cm^2$. These results showed close correlation with the insect population captured by trap A and B. The numbers of insects captured by trap A and B between the end of July and late August were similar. After spraying thiodicarb on August 28, the number of apple leafminers captured by trap B is bigger than that of trap A. It appears that pest occurrence tended to be high at low adhesion amounts of the active ingredient. Therefore, in order to obtain an optimal control effect, it is suggested that uniform application of insecticides is critical instead of relying on the amount of insecticide applied in the field.

A Study on the Adhesion of Zinc thin Film Deposited by Thermal Evaporation (열증착에 의한 아연박막 밀착성에 관한 연구)

  • 김영호;김경미;신순범;이상래
    • Journal of the Korean institute of surface engineering
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    • v.26 no.1
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    • pp.11-21
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    • 1993
  • The relationship between the amount of deposited-Zn and the adhesion of Zn film has beend investigated. This study changed the mild steel substrate temperature range of $100^{\circ}C$~$250^{\circ}C$, with the aim of studying the adhesion of Zn film coated by PVD on substrates in 10-2~10-3torr and deoxidant gas atmospheres 50%H2~50%N2 and 75%H2+25%N2. The result revealed that the adhesion of Zn film was remarkably good in a 75% H2+25%N2 gas atmosphere as well as deoxidant time was short, and with increasing the substrate tempera-ture up to $250^{\circ}C$. Whiled the amount of deposition tended to increase linearly with time at constant evaporation temperature. It was almost constant when the substrate temperature was lower than $200^{\circ}C$, slightly decreased between $200^{\circ}C$ and $250^{\circ}C$ and significantly decreased at $300^{\circ}C$.

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Effects of Surface Pretreatment on Deposition and Adhesion of Electrophoretic Paint on AZ31 Mg Alloy

  • Nguyen, Van Phuonga;Moon, Sungmo
    • Journal of the Korean institute of surface engineering
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    • v.50 no.2
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    • pp.72-84
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    • 2017
  • In this work, electrophoretic paint (E-paint) was deposited on AZ31 Mg alloy after four different surface pretreatments: knife abrading, SiC paper abrading, deionized (DI) water immersion and NaOH immersion. The deposition process of E-paint was studied by analyses of voltage-time and current-time curves, amount of deposited paint, current efficiency and surface oxide film resistance and the adhesion of E-paint was examined by tape test before and after immersion in DI water for 500 h at $40$^{\circ}C$. It was found that the induction time for the deposition, the amount of deposited paint and the current efficiency are inversely proportional to the resistances of surface films prepared by different surface pretreatment methods. The electrophoretic painting showed longer inductance time, larger amount of deposited paint and higher current efficiency on the highly conducting surfaces, such as knife-abraded and SiC-abraded surfaces than on the less conducting surfaces, such as DI water-immersed and NaOH-immersed samples. Excellent adhesion was observed on the E-paintings deposited onto knife-abraded and SiC-abraded AZ31 Mg alloy samplesSiC-abraded AZ31 Mg alloy samples.

Influence of Interaction of Surface Charges of PET Fiber and $\alpha$-Fe2O3 Particle on Detergency of Particulate Soil (PET섬유와 $\alpha-Fe_2O_3$ 입자의 표면전하간 상호작용이 고형오구의 세척성에 미치는 영향)

  • 강인숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.8
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    • pp.1132-1140
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    • 1998
  • The adhesion and removal of $\alpha$-Fe2O3 particles on the from PET fabric in NPE solution with different ionic strength were discussed in terms of interaction of surface charge of particle and substrate. The adhesion of $\alpha$-Fe2O3 particles to PET fabric and its removal from PET fabric were carried out by using water bath shaker and Terg-O-Tometer under various solution conditions. The ζ potential of PET fiber and $\alpha$-Fe2O3 particles in the detergent solution were measured by steaming potential and microelectrophoresis methods, respectively. The adhesion and removal amount of $\alpha$-Fe2O3 particles on the from PET fabric increased with increasing time of adhesion and removal, and the rates of adhesion and removal were high at the initial stage of adhesion and removal, and then the rates decreased with passing time. The adhesion and removal amount of $\alpha$-Fe2O3 particles on and from PET fabric increased with increasing pH of solution regardless ionic strength. The tendencies and degree of adhesion and removal were very similar regardless interaction of surface charge of particle and fiber. Therefore, in the presence of a surfactant and electrolyte, the influence of interaction of surface charge of particle and substrate on the detergency of particulate soil was small.

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Adhesion between Cu-18wt% Cr Alloy Film and Polyimide : Effect of Heat Treatment (Cu-18wt% Cr 합금박막과 폴리이미드사이의 접착력 : 열처리 영향)

  • 임준홍;김영호;한승희
    • Journal of the Korean institute of surface engineering
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    • v.26 no.6
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    • pp.327-333
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    • 1993
  • The effect of heat treatment on the adhesion between Cu-18wt% Cr film and polyimide has been studied by using T-peel test, AES, and XRD. Cu-18wt% Cr alloy and pure Cu films were sputter deposited onto pol-yimide. Cu was electroplated before and after heat treatment at $400^{\circ}C$ for 0.5 hr and 2 hrs respectively. The adhesion of metal film onto polyimide was considerably good before heat treatment, but heat treatment re-duced the peel adhesion strength in all specimens. The reduction in adhesion in adhesion strength values in the specimens which were plated after heat treatment was mainly due to Cr-O rich pahse formed in the metal/polyimide in-terface. In the specimens which were heat treated after plating, the enhanced ductility in the metal films con-tributes the peel adhesion strength by increasing the amount of deformation in metal strips.

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Effect of Additional Electrical Current on Adhesion Strength between Copper and Polyimide Films (인가 전류가 구리 도금 피막과 폴리이미드 필름의 접합력에 미치는 영향)

  • Lee, Jang-Hun;Han, Yoonsung;Lee, Ho-Nyun;Hur, Jin-Young;Lee, Hong Kee
    • Journal of the Korean institute of surface engineering
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    • v.46 no.1
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    • pp.9-15
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    • 2013
  • The effect of the additionally applied electrical current on the adhesion strength between electroless Cu and polyimide films was investigated. Peel tests were performed after applying electrical current within the range from 0.1 to 100 mA for the duration from 1 to 30 minutes. Sample with more than 1 mA of additional electrical current for 1 minute showed higher adhesion strength than that without additional electrical current. However, samples with 10 mA of additional electrical current for more than 10 miniutes showed the degradation of adhesion strength. Ra and RMS values of the peeled polyimide surface were proportional to the adhesion strength though there were no significant changes in the morphology of the peeled surfaces with varied amount and time-length of additional electrical current. Applying electrical current could increase the density of chemical bonding, which results in increase of the adhesion strength between copper and polyimide. However, in the case of applying additional electrical current for excessive amount or time, the degradation of the adhesion strength owing to the formation of copper oxide at the interface could occur.