• Composites Research
• /
• v.30 no.4
• /
• pp.254-260
• /
• 2017

In this paper, we investigated the application method and properties of 0.1 mm, 0.2 mm and 0.3 mm beads, which can secure a certain thickness due to the molding stability of joint surfaces of different materials (aluminum and composite). In order to verify this, the influence was evaluated according to the thickness of the adhesive in the Double lap test and the FEM simulation. As a result, it was confirmed that as the content of the bead of the adhesive increased more than 1%, the strength of the adhesion increased and the elongation decreased. We confirmed as the size of the bead became larger, the rigidity became lower and the elongation increased.

• Biomedical Science Letters
• /
• v.11 no.3
• /
• pp.337-341
• /
• 2005

This study was undertaken to clerify the cytotoxic effect of syringic acid by colorimetric assay on human cancer cells. For the evaluation of cytotoxicity of syringic acid, the cell viability and cell adhesion activity of syringic acid on cancer cells, human oral epithelioid carcinoma cells were determined using by colorimetric assays such as MTT (3-[4,5­dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and XTT (2,3-bis-[2-methoxy-4-nitro-5-sulfophenyl]­2H-tetrazolium-5-caboxanilide) assay, respectively after human oral epithelioid carcinoma cells were treated with syringic acid for 48 hours. In this study, the cell viability of syringic acid on human oral epithelioid carcinoma cells showed a significant decrease by MTT assay compared with control, and also, the cell adhesion activity by XTT assay was decreased significantly in these cells after cells were treated with various concentrations of syringic acid for 48 hours. $MTT_{50}\;and\;XTT_{50}\;were\;282.3\;{\mu}M\;and\;418.8{\mu}M$ syringic acid, respectively. These results suggest that syringic acid shows midcytotoxic effect on human oral epithelioid carcinoma cells by the decreasement of the cell viability and the cell adehision activity assessed by colorimetric assay in these cultures.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.333-336
• /
• 1997

The adhesion of activated and normal platelets to fibrinogen requires the receptor binding site of GPIIb/IIIa. These recognition sites exists in the A ${\alpha}$ chain(RGDS at 572-575 and RGDF at 95-98) and the carboxy-terminal of ${\gamma}$ chain (HHLGGAKQAGDV at 400-411) of fibrinogen. In this study, we developed RGDF-immobilized surface to detect the unctional state of platelet. RGDF-immobilized surface was prepared on the glass using photolithographic technology. Platelet adhesion to RGDF-immobilized surface was observed by staining platelets with mepacrine using a fluorescence microscope using mepacrine. Using the RGDF peptide of fragment E, we observed that the platelets pretreated with PGE1 interacted incompletely with RGDF-immobilized surface, whereas ADP activated platelets interacted with the surface extensively. These results show that the distinct selectivity of RGDF-immobilized micro-patterned surface can be used to detect the unctional state of platelets.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.7
• /
• pp.1349-1352
• /
• 2008

We report a novel patterning method for a homo-polymeric poly(3-hexylthiophene) (P3HT) nanofilm particularly capable of strong adhesion to a $SiO_2$ surface. An oxidized silicon wafer substrate was micro-contact printed with n-octadecyltrichlorosilane (OTS) monolayer, and subsequently its negative pattern was selfassembled with three different amino-functionalized alkylsilanes, (3-aminopropyl)trimethoxysilane (APS), N- (2-aminoethyl)-3-aminopropyltrimethoxy silane (EDAS), and (3-trimethoxysilylpropyl) diethylenetriamine (DETAS). Then, P3HT nanofilms were selectively grown on the aminosilane pre-patterned areas via the vapor phase polymerization method. To evaluate the adhesion, patterning, and the film itself, the PEDOT nanofilms and SAMs were investigated with a $Scotch^{(R)}$ tape test, contact angle analyzer, ATR-FT-IR, and optical and atomic force microscopes. The evaluation showed that the newly developed all bottom-up process can offer a simple and inexpensive patterning method for P3HT nanofilms robustly adhered to an oxidized Si wafer surface by the mediation of $FeCl_3$ and amino-functionalized alkylsilane SAMs.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.132-145
• /
• 1996

Ethyl ether fractions of Ferula Resina(EFR) and Lithospermi Radix(ELR) and hexane fraction of Salviae miltiorrhizae Radix(HSR) exerted an inhibitory effect on cell adhesion of A549 to extracelluar matrix most effectively in vitro cell adhesion assay. Thus, with above fractions for the evaluation of antitumor activity, T／C% was monitored in ICR bearing S-180 and for antimetastatic effect, pulmonary colonization assay, weight of organs, changes of WBC and platelet were studied. In pulmonary colonization assay incidence rate to control was 73 % 42 %, 14 % in ELR, HSR and EFR-treated groups repsectively. Gain of lung weight was significantly inhibited in all groups while spleen weight was significantly reduced only in SMR group, but no changes in kidney and liver as compared with control. Number of platelet was significantly increased in all groups to normal range as compared with thrombocytopenic contol. WBC was significantly reduced only in LR group. These results suggest that ethyl ether fraction of Ferula Resina has more effective antimetastatic activity.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.3
• /
• pp.692-697
• /
• 1997

A 62-year-old male was admitted for evaluation of a mass shadow on chest film. Chest PA showed $7{\times}5cm$ lobulated homogenous mass in right upper medial area of lung. On chest computed tomography, there was a large irregularly lobulated mass with central necrotic low density area in apical segment of right upper lobe. Right upper lobectomy of the lung was performed. Partial adhesion to parietal pleura of posterior mediastinum and severe adhesion to right upper apicoposterior segment was found during the operation. Microscopic and ultrastructural studies(including immunocytochemical stains) of the mass revealed malignant fibrous histiocytoma.

• Journal of the Korean Society of Safety
• /
• v.13 no.3
• /
• pp.102-111
• /
• 1998

This study was concerned with the development of a heavy duty rust-converting agent, the function of which is to form metal complex coatings, containing vinyl halide-acrylic terpolymer emulsion, defoamer, emulsifying agent, glass flakes, chelating agent such as gallotannic acid, gallic acid, and pyrogallic acid, and other additives. The resulted emulsion products(Sample No.1~No.5) were characterized through test either in the forms of emulsions, which include Viscosity, Penetration rate, Acidity and Film drying rate test, or in the forms of coated layer on rusty steel substrates by FT-IR, which include hardness, gloss, salt spray, adhesion and flame retardant test. The test results are as follows ; Penetration rate(0.1~0.4 mm/min), Solid content(70%), Acidity (pH 1.8~2.0), Specific gravity(1.30~1.35), Film drying rate(108min, RH 40% ; 150min, RH 80%), Gloss(83~92, incident angle $60^{\circ}$; 88~97, incident angle $85^{\circ}$), Pencil hardness(4H~5H), Adhesion (100/100), Salt spray test(>720Hr), LOI(%) value(38%), Vertical burning test(UL 94-v-l). According to the various performance of specimens show above, the evaluation of the availability of this heavy duty rust-converting agent can be concluded that all the samples(No.1~No.5) are capable of being used in the field of chemical plant and in the hazard areas of fire and explosion potential. It was observed that the properties of sample No.2, especially gloss and hardness, were much better than that of the other samples.

• Journal of the Korea Institute of Building Construction
• /
• v.3 no.4
• /
• pp.103-109
• /
• 2003

Reinforced concrete structures under sever conditions such as marine structures, bridges and structural constructed with aggregated(dredged front sea). can be deteriorated from corrosion of the reinforcing bars. The purpose of this study is to evaluate the corrosion reflectance of coated steel using polymer dispersion and polymer cement slurry. Polymer dispersion and polymer cement slurry with various polymer types were coated to the surface of bars and steel plate, and tested for accelerated corrosion tests. Tests include adhesion in tension, bending test, chloride ion spray, penetration of NaCl 10％ solution and carbonation. From the test results, the corrosive resistance of steel is considerably improved by using polymer dispersion and polymer cement flurry at surface of steel. The difference of the corrosive resistance is hardly recognized according to types of polymer dispersion. The coated steel using polymer dispersion and polymer foment slurry will be improved to a great extent compared to those of plain steel when increasing content of chloride ion in cement concrete.

• Journal of the Korean Society for Heat Treatment
• /
• v.32 no.5
• /
• pp.224-229
• /
• 2019

PVD coating is a technology that can be applied to various industries, and is widely used for processing molds and machinery, improving performance of core parts, and extending the life. Therefore, there is a need for a research on a device and a process technology that can adjust the performance to suit each application. In this study, a PVD coating device with ion density control was used to deposit a coating layer on SKD 11, a cold die steel, with magnetron currents of 1 A, 2 A, 3 A at arc currents of 80 A, 100 A, 130 A. It examined the mechanical properties for each condition. Increasing the arc current and magnetron current could improve the thickness, adhesion, and hardness of the coating layer. Especially, When the magnetron current was high, it suppressed the droplets that could be generated by the high arc current, showing excellent surface uniformity and adhesion of the coating layer.

• International Journal of Highway Engineering
• /
• v.16 no.5
• /
• pp.73-82
• /
• 2014

PURPOSES : The purpose of this study is to determine the optimum addition rate of SBR latex through the evaluation of durability and strength of SBR latex applied soil pavement. Formerly used materials such as fly ash and cement in soil pavement had resulted in decreased durability due to micro crack by heat of hydration and shrinkage crack in winter. However, that agglutinated polymers help adhesion to aggregate increased comes up with preventing the crack opening when the number of capillary tubes of SBR latex get decreased in the hydration process of cement. Therefore, in this study, it is suggested that the evaluation of the field applicability of soil pavement be conducted through the performance lab test in terms of strength increment, adhesion improvement, and crack resistance based on SBR latex addition rate. METHODS : In order to evaluate the field applicability of soil pavement, SBR latex was added 0 to 3% by 1% increment, with fixed cement contents of 3% and 5%. The resistance of shear failure and crack of soil pavement were evaluated by performing the uniaxial compressive strength test and indirect tensile strength test at -20 and $20^{\circ}C$, respectively. RESULTSCONCLUSIONS : It was found out that from both tests, resistance of shear failure and crack were improved with increment of curing time, and especially more than 2% of SBR latex addition rate and 5% cement content gave better results.