• 보존과학회지
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• 제34권3호
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• pp.157-166
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• 2018

본 연구에서는 아교의 접착 특성 향상을 위해 가교제(Cross-linking Agent)를 첨가하는 방법으로 젤라틴 결합력을 증대하였다. 제니핀 첨가 아교는 물성 측정, 구조 분석, 색잔류도, 용출도, 파단강도를 측정하였으며, 수분과 자외선에 대한 내수성과 내광성을 비교하였다. 연구 결과 겔강도와 점도는 제니핀 첨가량에 따라 증가하였다. 구조분석 결과, 젤라틴에서는 구조적으로 안정된 콜라겐의 3중 구조의 흡수 피크가 관찰되었다. 색잔류도 결과, 명도가 낮아지기 때문에 피막이 관찰되는 것으로 판단된다. 용출량은 $50^{\circ}C$ 증류수에서 제니핀 첨가량이 증가할수록 용출된 아교 양이 증가하였고 파단강도는 제니핀 첨가량에 따라 증가하였다. 내수성과 내광성은 제니핀 첨가에 따른 열화 전 후 양상이 나타나지 않았다. 본 연구 결과를 바탕으로 제니핀 첨가 아교의 접착 특성을 확인할 수 있었으며 아교에 적용 가능한 실험 방법을 고찰하였다. 제니핀을 첨가한 후에도 아교 고유의 특성인 유연성, 재용해성, 접착력, 경화속도가 사라지지 않고 향상되기 때문에 균질한 아교가 확보된다면 문화재 보존 및 아교 제작에 적용이 가능할 것으로 기대한다.

• 한국환경과학회지
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• 제30권12호
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• pp.1041-1051
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• 2021

The purpose of this study was to identify for extenders, adhesives, colorants, and fungicides suitable for the production of high-quality film-coated seeds of Chinese cabbage. In addition, the effect of various additives used for film coating on the germination of coated seeds and seedling vigor was investigated to establish appropriate treatment conditions for film coating efficiency. The germination rate and germination speed in Chinese cabbage film-coated seeds did not differ significantly depending on the type and concentration of the extender, while the use of Talc resulted in superior granulation capacity and adhesion of the seed coat in comparison to Zeolite. There was no significant difference in the germination rate depending on the type of adhesive used for film coating of Chinese cabbage seeds, but the germination rate was slightly slower in the film-coated seeds using carboxymethyl cellulose as an adhesive. On the other hand, the seeds coated with a film using 1% PVA as an adhesive not only maintained hardness enough to withstand external pressure, but also showed a high germination rate. In addition, the suitable disinfectant for film coating was venoram, and the treatment concentration was good at 250 mg·L^-1. The type of colorant used in the film-coated seeds of Chinese cabbage did not significantly affect the germination rate, germination speed, and seedling vigor. The seeds film-coated using the liquid colorant were superior in appearance to the seeds film-coated with the solid colorant, which implies the possibility of reduction in the manufacturing costs by using the water-soluble paints as colorants for film-coated seeds.

• 대한치과교정학회지
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• 제31권2호통권85호
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• pp.261-270
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• 2001

본 연구의 목적은 bracket 부착시 광조사시간을 획기적으로 감소시킬 수 있는 plasma arc light의 임상적 유용성을 visible light 중합시의 전단결합강도와 접착파절양상과 비교해 봄으로써 평가해 보는데 있다. 사람의 상하악 소구치를 포매하여 만든 레진블럭시편에 광중합 접착제인 Transbond$^{\circledR}$를 사용하여 수종의 bracket을 각각의 조건에 따라 부착한 후 만능 물성시험기를 이용하여 전단결합강도를 측정하고, 접착파절양상을 stereoscope을 이용하여 관찰하여 다음과 같은 결과를 얻었다. 1. Plasma arc light를 이용한 수종의 bracket 접착시 metal bracket과 ceramic bracket의 전단결합강도는 임상적으로 사용하기에 충분한 값을 나타내었으며, resin bracket 경우 다른 bracket 비해 전단결합강도가 현저히 작은 값을 나타내었지만 임상적으로 사용이 가능한 값을 나타내었다. 2. Visible light를 이용한 metal bracket의 광중합시 광조사시간에 따른 전단결합강도는 광조사 시간에 따른 유의한 차이를 보이지 않았으며, 임상적으로 사용하기에 충분한 강도를 나타내었다. 3. Plasma arc light를 이용한 수종의 bracket 접착시 접착제 잔류지수를 통해 접착파절양상을 관찰한 결과, metal bracket과 resin bracket 경우 bracket기저면에 접착제가 반 이상 남아 있지 않은 경우가 많았으며, ceramic bracket의 경우 bracket기저면에 접착제가 반 이상 남아 있는 경우가 많았다. 4. Metal bracket의 부착시 plasma arc light를 2초간 광조사한 군과 visible light를 10초간 광조사한 군의 전단결합강도와 접착파절양상을 비교시 유의한 차이를 보이지 않았다. 6. Plasma arc light를 이용한 광중합시 광조사 거리에 따른 전단결합강도는 거리가 증가할수록 감소하였다. 이상의 실험 결과는 plasma arc light를 이용한 bracket의 접착시 전단결합강도 저하의 우려 없이 임상적으로 사용 가능함을 시사한다.

• Biomolecules & Therapeutics
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• 제9권4호
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• pp.298-306
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• 2001

To develop a novel transdermal delivery system of loxoprofen (LP), a potent antiinflammatory and analgesic agent, the effects of vehicle composition and drug loading dose on the skin permeation property were investigated. And in vivo skin absorption property studied by analysing the $C_{max}$ and AUC was investigated after applying the developed plaster systems on rabbit back skin. Addition of isopropyl myristate (IPM) and IPM-diethylene glycol monoethyl ether (DGME) cosolvent in the plaster showed higher permeation rates than those from propylene glycol laurate-DGME cosolvent systems. As the concentration of LP in the plaster increased from 0.56 mg/$\textrm{cm}^2$ to 1.19 mg/$\textrm{cm}^2$, the drug release and skin permeation rates increased linearly. At loading dose of 1.19 mg/$\textrm{cm}^2$, the flux reached 35.6 $\mu$g/$\textrm{cm}^2$/hr. New LP plasters showed a good adhesive property onto skin, and showed no crystal formation. The AU $C_{0-24hr}$ and $C_{max}$ after dermal application of LP plaster (60 mg/70 $\textrm{cm}^2$) were found to be 6951$\pm$230 ng.hr/ml and 400$\pm$44 ng/ml, respectively. And the plasma concentration maintained above 300 ng/ml up to 24 hr period. In the carrageenan-induced rat paw edema test, LP plaster showed similar inhibition rate with marketed ketoprofen (Ketoto $p^{R}$) plaster.aster.r.

• Structural Engineering and Mechanics
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• 제74권4호
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• pp.457-470
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• 2020

The force resisting ability of a connection has direct implications on the overall response of a timber framed structure to various actions, thereby governing the integrity and safety of such constructions. The behavior of timber framed structures has been studied by many researchers by testing full-scale-connections in timber frames so as to establish consistent design provisions on the same. However, much emphasis in this approach has been unidirectional, that has focused on a particular connection configuration, with no research output stressing on the refinement of the existing connection details in order to optimize their performance. In this regard, addition of adhesive to dowelled timber connections is an economically effective technique that has a potential to improve their performance. Therefore, a comparative study to evaluate the performance of various full-scale timber frame Nailed connections (Bridled Tenon, Cross Halved, Dovetail Halved and Mortise Tenon) supplemented by adhesive with respect to Nailed-Only counterparts under tensile loading has been investigated in this paper. The load-deformation values measured have been used to calculate stiffness, load capacity and ductility in both the connection forms (with and without adhesion) which in turn have been compared to other configurations along with the observed failure modes. The observed load capacity of the tested models has also been compared to the design strengths predicted by National Design Specifications (NDS-2018) for timber construction. Additionally, the experimental behavior was validated by developing non-linear finite element models in ABAQUS. All the results showed incorporation of adhesive to be an efficient and an economical technique in significantly enhancing the performance of various timber nailed connections under tensile action. Thus, this research is novel in a sense that it not only explores the tensile behavior of different nailed joint configurations common in timber construction but also stresses on improvising the same in a logical manner hence making it distinctive in its approach.

• 구강회복응용과학지
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• 제23권4호
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• pp.283-292
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• 2007

Two-step or one-step bonding systems generally inhibit curing process of dual-cured core build-up resin composite for their adhesive acidity. In addition this dual-cured core build-up resin composite can be applied to dentin of pulp chamber and root at the time that complete the endodontic treatment. The purpose of this investigation was to determine the influence of sodium hypochlorite on rnicrotensile bond strength of dual-cured core build-up resin composite. Extracted human molars were horizontally sectioned with 1mm thickness using low speed diamond saw. After the sectioned specimens were divided into 8 groups, adhesive systems (Clearfil SE-Bond, Prime&Bond NT[2-step, 1-step], Adper Prompt L-Pop) were then applied with or without sodium hypochlorite pretreatment. The treated specimen was filled with dual-cured core build-up resin composite (Luxacore, DMG corp., German). Then light cured for 40 seconds and soaked in $37^{\circ}C$ water bath for 24 hours. After the treated specimen was grinded with 1mm width and measured rnicrotensile bond strength by testing machine. Additionally 8 teeth were prepared for SEM evaluation. The results were as follows. : NaOCl treated groups generally had lower rnicrotensile bond strength but did not show any difference statistically except Adper Prompt L-Pop. When the teeth were treated by NaOCl, though the difference of applied adhesive system, it had no statistically significant difference within the NaOCl treated groups except the relation of between ClearFil SE-Bond adhesive system and Adper Prompt L-Pop adhesive system. In the SEM evaluation, NaOCl treated groups presented relatively long resin tags and incomplete hybrid layer formation generally.

• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.49-54
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• 2020

신축/유연한 전극을 무언가에 접착하거나 전극에 무언가를 접착하기 위해서는 전극의 특성에 맞는 전도성 접착제가 필요하다. 전도성 접착제는 접착성과 전도성이 필수적으로 요구된다. 특히 접착성 부분은 내구성과 내열성이 요구되며 기존 접착제와 다르게 전도성까지 보유해야한다. 그러기 위해서는 강도와 접착성이 좋은 에폭시를 접착제로 선정하였고 여기에 기존 주제와 경화제로 이루어진 2액형 소재가 아닌 가소제와 보강제까지 혼합하여 4액형 소재를 사용하여 신축/유연성을 고분자에 부여하였다. 전도성 필러는 비저항이 낮은 재료인 은으로 선정하였고 높은 전도성을 위해 3가지 모양의 Ag 입자를 사용해 패킹성을 높였다. 이렇게 개발된 전도성 접착제와 실제 판매되고 있는 에폭시 기반 전도성 접착제 2개와 전도성을 비교하였고 실제 판매되고 있는 제품보다 약 10배정도의 우수한 전도성 결과가 도출되었다. 그리고 가소제와 보강제 여부에 따른 전도성, 기계적 특성, 접착력, 강도를 평가하였다. 또한 120℃에서 5분 경화 후에 60%의 인장에도 문제가 없었으며 연필경도는 6H로 우수하게 측정되었다. 3M tape test를 통해 전극의 접착력을 확인한 결과 바인더의 배합 비율에 관계없이 모두 우수한 결과를 보였다. 전극 위에 Cu sheet를 전도성 접착제를 통해 부착시킨 후 접촉저항을 확인한 결과 0.3 Ω으로 우수한 성능을 보였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.31-34
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• 2003

Sandwich panel is composed of the facing sheets which support the external load, the cellular core with the low thermal conductivity and the adhesive agent to bond them. The cellular core was produced by binding lightweight cellular aggregates with cement and two types of acrylic base St/BA emulsion were added with a view to improving the workability ion due to high absorption of light weight aggregate and to develope more strength, respectively. This investigation is to comprehend the effect of the addition of two types of St/BA on thermal conductivity, calorific value and exhaustion content of noxious gas in addition re compressive and flexural strength. Flexural strength of the specimen made with St/BA-2 ranged 20kgf/cm2 to 25kgf/cm2 and was about 50% to 100% as high as that of the non-fiber specimen. Thermal conductivity was recorded from 2.0 to 3.0 kcal/mh$^{\circ}C$ and calorific value of St/BA modified specimen was much lower than that of commercial sandwich panel core of EPS and urethane. Careful caution has to be taken because generation of noxious gas such as CO, NO and SO2 tend to increase with addition of polymer cement ratio.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.922-927
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• 2001

In an effort to regulate the mammalian cell behavior in entrapment with a gel, we have functionalized hydrogels with the putative cell-binding (-Arg-Gly-Asp-)(RGD) domain. An adhesion molecule of Gly-Arg-Gly-Asp-Ser (GRGDS) peptides, a cell recognition ligand, was induced into thermo-reversible hydrogels, composed of N-isopropylacrylamide with small amounts of acrylic acid (typically 2-5 $mol\%$ in feed), as a biomimetic extracellular matrix (ECM). The GRGDS containing a p(NiPAAm-co-AAc) copolymer gel was studied in vitro for its ability to promote the spreading and viability of cells by introducing a GRGDS sequence. Hydrogel with no adhesion molecule was a poor ECM for adhesion, permiting spreading of only $3\%$ of the seeded cells for 36h. By immobilizing the peptide linkage into the hydrogel, the conjugation of RGD promoted $50\%$ of proliferation for 36h. However, the GREDS sequence, nonadhesive peptide linkage, conjugated hydrogel showed only $5\%$ of the seeded cell for the same time period. In addition, with the serum-free medium, only GRGDS peptides conjugated to hydrogel was able to promotecell spreading, while there was no cell proliferation in the hydrogel without GRGDS. Thus, the GRGDS peptide-conjugated thermo-reversible hydrogel specifically mediated the cell spreading. This result suggests that utilization of peptide sequences conjugating with the cell-adhesive motifs can enhance the degree of cell surface interaction and influence the long-term formation of ECM in vitro.

• Restorative Dentistry and Endodontics
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• 제28권3호
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• pp.209-221
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• 2003

The objectiveness of this study was to evaluate whether low-viscosity composite can bond effectively to dentin surface without bonding resin. The low-viscosity composites being 50wt% filler content were made by the inclusion of bonding resin of two self-etching systems(Cleafil SE Bond, Unifil Bond) varied with contents as 0, 10, 20, 30, 40, 50wt%. Exposed dentin surfaces of extracted 3rd molars are used. Dentin bond strengths were measured. The tests were carried out with a micro-shear device placed testing machine at a CHS of 1mm/min after a low-viscosity composite was filled into an iris cut from micro tygon tubing with internal diameter approximately 0.8mm and height of 1.0mm. 1 Flexural strength and modulus was increased with the addition of bonding resin. 2. Micro-shear bond strength to dentin was improved according to content of bonding resin irrespective of applying or not bonding resin in bonding procedure, and that of Clearfil SE Bond groups was higher than Unifil Bond. 3. There were no significant difference whether use of each bonding resin in bonding procedure for S-40, S-50, U-50(p＞0.05). 4. In SEM examination, resin was well infiltrated into dentin after primed with self-etching primer only for S-50 and U-50 in spite of the formation of thinner hybrid layer. Low viscosity composite including some functional monomer may be used as dentin bonding resin without an intermediary bonding agent. It makes a simplified bonding procedure and foresees the possibility of self-adhesive restorative material.