• Title/Summary/Keyword: Adhesive patterns

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Shear bond strength and adhesive failure pattern in bracket bonding with plasma arc light (Plasma arc light를 이용한 bracket 부착시의 전단결합강도와 파절양상의 유형)

  • Yoo, Hyung-Seok;Oh, Young-Geun;Lee, Seung-Yeon;Park, Young-Chel
    • The korean journal of orthodontics
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    • v.31 no.2 s.85
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    • pp.261-270
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    • 2001
  • The purpose of this study was to evaluate the clinical usefulness of plasma arc light which can reduce the curing time dramatically compared by shear bond strengths and failure patterns of the brackets bonded with visible light in direct bracket bonding. Some kinds of brackets were bonded with the Transbond$^{\circledR}$ to the human premolars which were embedded in the resin blocks according to the various conditions. After bonding, the shear bond strength was tested by Instron universal testing machine and in addition , the amount of residual adhesive remaining on the tooth after debonding was measured by the stereoscope and assessed with adhesive remnant index(ARI). The results were as follows : 1. When plasma arc light was used for bonding the brackets, the shear bond strength was clinically sufficient in both metal and ceramic brackets, but resin brackets showed significantly lower bond strength but which was clinically useful. 2. When metal brackets were bonded using visible light, there was no significant difference in shear bond strength due to the light-curing time and the bond strength was clinically sufficient. 3. When the adhesive failure patterns of brackets bonded with plasma arc light were observed by using the adhesive remnant index, the bond failure of the metal and resin bracket occurred more frequently at bracket-adhesive interface but the failure of the ceramic bracket occurred more frequently at enamel-adhesive interface. 4. There was no statistically significant difference of the shear bond strength and adhesive failure pattern between metal bracket bonded for 2 seconds by curing with plasma arc light and 10 seconds by curing with visible light. 6. When metal brackets were bonded using plasma arc light, the shear bond strength decreased as the distance from the light source increased. The above results suggest that plasma arc light can be clinically useful for bonding the brackets without fear of the decrease of the shear bond strength.

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Development of Nano Convergence Films Using a Roll-to-Roll Coating System

  • Hwang, Joong Kook;Chang, Sang-Mok;Shin, Hoon-Kyu
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.3
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    • pp.168-171
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    • 2016
  • There has been growing interest and rapid development in transparent electrode films, which are flexible and light and used in mobile, simple information, and electronic devices, and based on recent advancements in nano technology, information technology, and display technology. In particular, studies on developing such films with both high conductivity and high transmittance of visible rays are highly in demand for commercialization. In this study, transparent electrode films were developed for IT using micro patterns that show sheet resistance less than 10 Ω/□, adhesive strength more than 98%, and light transmittance more than 90%. The results of applying a surface emission gradient minimization (Honey Comb) technology to the films was the verification of the sheet resistance, adhesive strength, and light transmittance satisfying the target level of this study through Imprinting and Remolding processes.

Analysis of Characteristics of Functional Outers with Moisture-permeable Waterproof Fabric - Focus on Fabrics, Washing·Cares, Design, Patterns, Subsidiary Materials, and Sewing - (투습방수 직물을 사용한 기능성 아우터의 특성 분석 - 소재, 세탁·취급, 디자인, 패턴, 부자재, 봉제를 중심으로 -)

  • Roh, Eui Kyung;Yoon, Mi Kyung
    • Fashion & Textile Research Journal
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    • v.23 no.1
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    • pp.129-141
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    • 2021
  • This study investigated fabrics, washing and cares, design, pattern, subsidiary materials, and sewing methods with a focus on the functional outers using moisture-permeable waterproof fabric as a shell; in addition, each element was analyzed for differences depending on fabric type. The characteristics of 34 outers were investigated through labels, online product introductions, visual inspection, observations from two experts with more than 30 years experience and wear tests. Moisture-permeable waterproof fabrics used for the outer were classified into two types; in addition, the shell of the high-density fabric and the 2 & 3-layer fabrics had different characteristics. Various fabrics, detailed designs, and three-dimensional patterns suitable for each part of the human body were used to improve functionality. In addition, various subsidiary materials and sewing methods were used to form an organic relationship. The same washing and cares, patterns and subsidiary materials were used regardless of fabric type; however, the fabric type influenced the detailed design and sewing. The outers with high-density fabric had a loose fit, short placket, e-banded cuffs, lock-stitch, and lock-stitch+binding. However, the outer with 2 & 3 layer fabric had a slim fit, hood width adjustment, zippered pockets, cuffs with tab, seamless adhesive sewing such as laminating, lock-stitch+ seam-sealing, and welding.

Comparison of Mechanical and Interfacial Properties on Chemical Structures of Acrylic and Epoxy Adhesives (아크릴 및 에폭시 접착제의 화학적 구조에 따른 유리섬유 복합재료의 기계적 및 계면 물성 변화 평가)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Choi, Jin-Yeong;Kwon, Dong-Jun;Lee, Sang-Il;Park, Joung-Man
    • Composites Research
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    • v.29 no.2
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    • pp.79-84
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    • 2016
  • An adhesive can be used to connect two different materials in structures. In comparing with other connecting methods, such as bolt, rivet, and hot melting, the adhesive does not need to use them. It leads to reduce the weight and decrease the stress concentration along the connecting line. This work studied the comparison of mechanical and interfacial properties of commonly-used two adhesives, acrylic type and bisphenol-A epoxy type. Tensile and flexural strength of neat adhesives were also compared. Lap shear test of two adhesives was deduced from the measurement of tensile and fatigue tests. After testing, the failure patterns of adhesive surfaces were observed by a microscope. Tensile strength and mechanical fatigue resistance at using bisphenol-A epoxy adhesive were better than acrylic adhesive. Also adding CNT reinforcement in epoxy adhesive can anticipate mechanical improvement.

Effects of one or two applications of all-in-one adhesive on microtensile bond strength to unground enamel (Unground enamel에 대한 all-in-one adhesive의 1회 또는 2회 적용이 미세인장 결합강도에 미치는 영향)

  • Son, Chang-Yong;Kim, Hyeon-Cheol;Hur, Bock;Park, Jeong-Kil
    • Restorative Dentistry and Endodontics
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    • v.31 no.6
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    • pp.445-451
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    • 2006
  • The purposes of this study were to compare the effects of one or two applications of all-in-one adhesives on microtensile bond strengths (${\mu}$TBS) to unground enamel and to investigate the morphological changes in enamel surfaces treated with these adhesives using a scanning electron microscopy (SEM). Twenty-five noncarious, unrestored human mandibular molars were used. The unground enamel surfaces were cleansed with pumice. The following adhesives were applied to lingual, mid-coronal surfaces according to manufacture's directions; Clearfil SE bond in SE group, Adper Prompt L-Pop$^{TM}$1 coat in LP1 group, 2 coats in LP2 group, Xeno$^{\R}$III1 coat in XN1 group, and 2 coats in XN2 group. After application of the adhesives, a hybrid light-activated resin composite was built up on the unground enamel. Each tooth was sectioned to make a cross-sectional area of approximately 1.0 mm$^2$ for each stick. The microtensile bond strength was determined. Each specimen was observed under SEM to examine the morphological changes. Data were analyzed with one-way ANOVA. The results of this study were as follows; 1. The microtensile bond strength values were; SE (19.77 ${\pm}$ 2.44 MPa), LP1 (13.88 ${\pm}$ 3.67 MPa), LP2 (14.50 ${\pm}$ 2.52 MPa), XN1 (14.42 ${\pm}$ 2.51 MPa) and XN2 (15.28 ${\pm}$ 2.79 MPa). SE was significantly higher than the other groups in bond strength (p < 0.05). All groups except SE were not significantly different in bond strength (p < 0.05). 2. All groups were characterized as shallow and irregular etching patterns.

The shear bond strength and adhesive failure pattern in bracket bonding with different light-curing methods (브라켓 접착시 광중합방식에 따른 전단결합강도와 파절양상 비교)

  • Shin, Jai-Ho;Lim, Yong-Kyu;Lee, Dong-Yul
    • The korean journal of orthodontics
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    • v.34 no.4 s.105
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    • pp.333-342
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    • 2004
  • The purpose of this study was to evaluate the clinical effectiveness of a plasma arc light and light emitting diode (LED), compared with shear bond strength and the failure pattern of brackets bonded with visible light in direct bonding. Brackets were bonded with Transbond XT to 60 human premolars embedded in the resin blocks according to different light-curing methods. Then, the shear bond strength of each group was measured using a universal testing machine (Instron) and the adhesive failure pattern after debonding was visually examined by light microscope. The results were as follows: 1. The shear bond strength showed no significant difference between the visible light and light emitting diode, but the plasma arc light exhibited a significantly lower shear bond strength compared with the visible light and light emitting diode. 2. In the visible light and light emitting diode, adhesive failure patterns were similar. Bond failure occurred more frequently at the enamel-adhesive interface. 3. The bonding failure of brackets bonded with plasma arc light occurred more frequently at the bracket-adhesive interface. The results of this study suggest that plasma arc light, light emitting diode and visible light are all clinically useful in the direct bonding of orthodontic brackets.

A study on the relationship between the symptom of Shanghanlun(傷寒論) and the Nutritive-Gi(營氣) (『상한론(傷寒論)』 병증(病症)과 영기(營氣)의 관계에 대한 연구(硏究))

  • Bang, Jung-kyun
    • Journal of Korean Medical classics
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    • v.30 no.1
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    • pp.211-221
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    • 2017
  • Objectives : The practices of Wei-qi and Nutritive-qi are generally divided into external Mai and internal Mai. However, they are closely interrelated and practiced together. While taking these aspects into consideration, this paper attempts to make interpretations in relation with Nutritive-qi the disease pathogens that appear in Shanghanlun's disease symptoms. Methods : Using the practice and function of Nutritive-qi described in Huangdineijing, the paper shall make interpretations for the patterns of Mawhangtang, patterns of Gaejitang, and the pathologies of pain, oedema, and nosebleed as described in Shanghanlun. Results & Conclusions : The pain from the patterns of Gaejitang differ from that of the patterns of Mawhangtang. First, the pain from the the patterns of Gaejitang cannot be the main symptom. Even if there is a symptom of pain, it's severity is not serious. Second, the pain from the patterns of Gaejiang takes the form of stiffness, and not general bodily pain. The reason for this stiffness is because of the emptiness of Wei-qi that leads to the congestion of Nutritive-qi which in turn causes the lack of qi and blood flow in muscula area such as abdomins. The symptom of oedema where one's body becomes swollen comes from a number of pathogens. First, the flow of meridian becomes hindered due to external dampness, a character which tends to be adhesive when added with humidty, and this results in the blockage of water qi which then causes the coagulation of nutritive blood. Second, when toxic heat is repressed and blocked within the lesser-yang channel, lesser-yang meridian stops working, which causes nutritive blood to clog at the front and back of ears since lesser-yang channel flows through that portion of body. Third, although oedema is not specifically mentioned in the sentences, but there exists the patterns of Daechungyongtang where water lumps are formed due to the accumulation and blockage of watery dampness. The patterns of Daechungyongtang is cuased when meridian is hindered from externally discharging body fluid due to a problem with meridian that blocks the fumigated internal heat which turns into bodily fluid from being discharged externally.

The Study on Construction of Blue Jeans & Pressure (블루진의 설계와 피복압에 관한 연구)

  • 권윤희
    • Journal of the Korean Home Economics Association
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    • v.36 no.2
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    • pp.121-130
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    • 1998
  • The purpose of this study was construction of bell-bottom blue jeans according to change of flare line and investigate the effects clothing pressure according to various movements of the legs. In this study, movements of leg were classified by M1, M2, M3, M4.(M1:erecting, M2: leapfrogging position, M3:sit-on-one' keens position, M4:Traditional nobel-sitting position) The results were as follows: As usings the leg surface shell by the adhesive paper taping method, basic slacks pattern and blue jeans patterns according to change of flare line was constructed. The order of clothing pressure of the different patterns is C(the flare line is on the calf of the leg)>B(the flare line is on the knee)>A(the flare line is on the thigh). Clothing pressure in the knee point was highest and when the flare line was on the calf of the leg, clothing pressure showed high.

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Analysis of Voltage Generating Characteristics of Composite Rail Pad Composed of Piezoelectric PVDF Film and Polyurethane Bonding Materials (철도레일 복합 압전패드의 구성 차이에 따른 전압 발생 특성 분석)

  • Cho, Hojin;Lim, Yujin;Kim, Sung Su;Lee, Jong Kwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.6
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    • pp.381-386
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    • 2017
  • A railway track generates severe levels of vibrations. In order to reduce these vibrations and to provide structural stability, various rail pads, mats, etc., are used for vibration protection. In this study, a specially designed rail pad was developed to reduce vibration and to generate electric power simultaneously, that is, by using the vibrations generated by railway cars on the track. The newly developed rail pads were tested to evaluate the characteristics of electric power by investigating the generated voltage and the current levels and patterns. In addition, we proposed an optimal laminated structure and adhesive by comparing the voltage generated by each type of adhesive required for optimal adhesion of the rail pad and the piezoelectric device.

A STUDY ON FLEXURE STRENGTH OF THE SOLDER JOINTS FORMED USING VARIOUS SOLDERING TECHNIQUES FOR CERAMO-METAL ALLOYS (도재소부전장관용 합금의 납착방법에 따른 납착부 굽힘강도에 대한 연구)

  • Kim, Jin-Yeoul;Chun, Young-Charn
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.2
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    • pp.191-205
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    • 1993
  • In order to compare the strength of soldered joints relative to the various sol dering method, soldering processes were performed using Palladium based ceramo-metal alloy(Bond-on 4)and Nickel-cromium alloy(Vera Bond). The obtained data include difference in strength between presoldering and postsoldering The data also contain difference among postsoldered groups for 3 difference soldering methods(torch, infrared. Oven) The following results were obtained : 1. For postsoldering with Pd alloy, the oven-using group showed the highest strength while the difference in strength between the torch-using group and the infrared machine group was negligible. 2. For Pd alloy with the torch method, postsoldering resulted in the higher strength than presoldering. 3. There was a negligible difference in strength between presoldering and postsoldering when Ni-Cr alloy with torch method is used. 4. Through microscopic study of the fractured surfaces, the torch-using group showed more porosity than both the oven-using and the infrared machine groups. 5. In terms of fracturing patterns, the oven-using group showed adhesive failure while both the torch and the infrared machine groups showed cohesive failure and cohesive-adhesive failure.

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