• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.306-307
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• 2014

진공용 장비의 sealing 방법으로 Cu gasket을 이용한 CF type과 O-ring을 이용한 NW type이 있다. 이중 O-ring을 이용한 sealing 방법에는 clamp를 사용하게 되는데 Al 합금으로 제작된 clamp에 bellows의 수축 시 받는 전단응력과 전단응력한계 이상의 힘을 받았을 때의 clamp 파손에 따른 역압에 의한 TMP 손상 분석.

• Journal of the Korean institute of surface engineering
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• v.53 no.5
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• pp.249-256
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• 2020

As the size of manufacturing equipment for LCD and OLED displays increases, replacement of existing heavy stainless steel components with light metals, such as aluminum alloys, is being more important in semiconducting and display manufacturing industries. To use aluminum alloys for components in semiconducting and display industries, it is important to develop a new anodization method for improved performance of anodic oxide films than conventional anodization method based on sulfuric acid. In this work, optimum applied current density and the best sealing methods for anodic oxide films in 3% oxalic acid were explored. Experimental results showed 2.5 A/dm2 is the best applied current density for improved hardness and dielectric breakdown voltage. Sealing of the anodic oxide films further improved their hardness, dielectric breakdown voltage and resistance to HCl, by which application of anodic oxide films become applicable for components in semiconducting and display industries.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.65-69
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• 2001

In this study, the deformation of the free surface motion of a magnetic fluid for the change in electromagnetic force is discussed. In case, magnetic fluid in characteristics of fluid adjusted to the opposite direction of the gravity direction. Thus, the device of a magnetic fluid proposed the complete zero-leakage Sealing and the surface actuator. The device of surface deformation as well comparison between numerical simulation and experiments as will be presented.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.767-780
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• 1997

One of the most common problems of implant prosthesis is the screw loosening of abutment screws. This brings on discomfort in mastication, inflammation in the peri-implant tissue due to poor oral hygiene and fracture of prosthesis or loss of osseointegration. To prevent screw loosening, appropriate implantation to direct the occlusal force to the long axis of the implant, accurate design of the superstructure, decrease of the occlusal table, and adequate torque on the abutment screw are necessary. In this study the screw loosening torque was evaluated in implants with dimples or flutes in the internal surface of abutment screw holes. The abutments were fastened with slot type and hexagonal type abutment screws and were sealed with vinyl poly siloxane impression and bite registration material respectively. The screw loosening torque was evaluated after 1,800 and 12,600 times loading under a loading machine. The results were as follows. 1. The flute form group showed significantly higher loosening torque compared to the dimple form group and the group with no inner surface treatment (p<0.05). 2. There was no statistical difference in loosening torque according to the sealing materials. 3. The loosening torque according to the types of abutment screw showed no significant difference. 4. The loosening torque was significantly higher after 1800 times loading compared to 12600 times loading(p<0.05). From the above results. it is thought that formation of a flute in the internal surface of the screw hole decreases the chance of screw loosening, but the sealing materials and types of abutment screw did not show significant difference in prevention of screw loosening.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.103-109
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• 2020

Purpose: The purpose of this study was to evaluate the preload maintenance of the retaining screw when using anaerobic sealing agents in implant fixture and abutment components. Specifically, the study examines the effects of anaerobic sealing agents on different types of screws. Materials and methods: External hexagon implants made of titanium and anti-rotational abutments were used. Titanium abutment screws and ebony abutment screws from the same manufacturer were used. The experiment was divided into four groups (n = 10 in each group). In the control group, no sealing agent was used at the implant fixture and abutment screw interface. All abutment screws were tightened according to the manufacturer's recommended torque (30 N.cm). After 24 hours, the removal torque (detorque) of each screw was measured using a digital torque gauge device. The data were analyzed by two-way ANOVA test according to normality distribution satisfaction. Results: Looking at the results for each group, titanium screws and no treatment showed detorque values of 20.3 ± 1.6 N.cm. titanium screws and applied anaerobic sealing agent showed detorque values of 32.4 ± 6.7 N.cm. Ebony screws and no treatment showed detorque values of 20.2 ± 1.5 N.cm. ebony screws and applied anaerobic sealing agent showed detorque values of 30.4 ± 4.5 N.cm. Conclusion: The detorque value was higher in the case of using anaerobic sealing agents in both the titanium screw and ebony screw groups. But there was no difference between the two screws.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.394-403
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• 2009

As the minimally invasive approach against white spot like early caries lesions in proximal surfaces of the teeth, therapeutic sealing has been introduced and studied for effective materials and methods to arrest the early caries lesion effectively, which is still going on. This study was performed for the purpose of evaluating its validity for the non-cavitated lesions according to the depth from surface using therapeutic sealing followed by artificial caries induction and evaluation with micro-CT, and we obtained the results as follows. 1. It was revealed that the deeper the caries lesions are, the lower radiation intensity at lesion body areas in pre-treatment specimen. 2. In the sealed groups, there were no differences in radiation intensity between pre- and post-treatment, whereas there were significant decreases in unsealed groups(p<0.05). 3. Even in the specimens with the lesions reaching deeply into DEJ, the effect of sealing was significant(p<0.05). Conclusively, it was thought therapeutic sealing can be an effective tool against the early caries lesions, regardless of their depth into tooth, unless cavitated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.974-980
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• 2015

Arc thermal spray coating using Al-3%Mg thermal spray wire was carried out to prevent steel from corrosion damage under the marine environment. Post-sealing was applied to Al-3%Mg spray coating treatment using organic/inorganic composite ceramics in order to improve the corrosion resistance of the as-sprayed coating. The results of various electrochemical experiments with sealing treatment indicated that the improvement in corrosion resistance was observed due to low current density in all applied potential range during anodic and cathodic polarization experiments. Futhermore, the natural potential measurement exhibited severe potential fluctuation due to influence of micro-crack presence on the surface of sealed thermal spray coating layer. In addition, the sealed layer was easily eliminated during anodic polarization. Nevertheless, Al-3%Mg spray coating layer improved corrosion resistance by sealing treatment because the sealed coating efficiency was determined to be 92.11%, indicating the exterior environment barrier effect which is based on the Tafel analysis.

• Analytical Science and Technology
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• v.20 no.4
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• pp.261-267
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• 2007

The 20 L small chamber test method is to evaluate pollutants such as TVOC, formaldehyde emitted from building materials. This method was only designed to evaluate the surface emission of sample exposed in the chamber. In this method, building materials cut with a fixed standard size are fixed in a sample sealing box. The sample sealing box is put into the 20 L test chamber. This chamber is ventilated at a standard air change rate with purified air for 7 days then the sample from the chamber is collected and analyzed to measure the emission rate of TVOC and formaldehyde. In this method, however, if the sealing box does not guarantee airtightness, accurate evaluation for the building materials can not be achieved due to the pollutants emitted from edge of the sample so called, edge effect. This edge effect can be much greater when evaluating panels such as plywood, flooring due to their surface treatment. In this study, flooring was tested to check airtightness of the sample sealing box with analytic results between 1L and 20 L test chamber. Furniture materials like LPM coated one side surface treatment and MDF coated both sides surface treatment with LPM were tested to identify whether the improvement of the sample sealing box airtightness is possible with the comparison between existing and improved test method that low VOC emission tape was used to seal the sample edge. After 7 days, MDF TVOC emission rate was different according to the existence and nonexistence of tape. The emission rate of the existing test method was $0.009mg/m^2h$ and that of improved test method was $0.003mg/m^2h$. Relative standard deviation for the existing test method was $0.004mg/m^2h$ and relative standard deviation for the improved test method was $0.002mg/m^2h$ when the same sample was analyzed three times. The improved test method in this study using low VOC emission tape was effective and able to reduce the heterogeneous effect of the edge from the sample sealing box.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.307-315
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• 2001

The application of Nd:YAG laser and irrigants to the root surface can change its surface configurations. The purpose of this study was to investigate the effects of Nd:YAG laser and irrigants on the apical seal of obturated canals. In this study, 66 single rooted teeth were randomly assigned to 4 group of 14 teeth each. 8 teeth were served us positive and negative controls. The teeth were divided into 6 groups as follows. Group A: Nd:YAG laser, 5% NaOCl + Rc-prep Group B: Nd:YAG laser, Saline Group C: 5% NaOCl + Rc-prep Group D: Saline Group E: Positive control Group F: Negative control 66 teeth were instrumented using Maillefer ProFile$^{\circledR}$ (Orifice Shapers, .04 taper, .06 taper Dentsply, Switzerland). Two of each group were selected at random, and the canal wall surfaces were examined under a SEM. 12 teeth of each group were obturated using by lateral condensation technique. Specimens were immersed in india ink for 7days, decalcified by 10% nitric acid, dehydrated by 75. 80. 85, 90, 95 and 100% alcohol in order cleared by methyl salicylate and then measured of dye penetration with stereomicroscope($\times$15 magnification) and Image Pro plus. The data were analyzed statistically by one-way ANOVA test and Duncan's Multiple Range test. The results were as follows : 1. The mean leakage was 0.128$\pm$0.376 for group A, 0.237$\pm$0.325 for group B, 0.397$\pm$0.468 for group C, 0.586$\pm$0.402 for group D, and there were statistically significant differences between group A and group D, group B and group D. (p<0.05). 2. Group A had better sealing ability than Group C, but there was statistically no significant differences. (p>0.05). 3. Group B had better sealing ability than Group D and there was statistically significant difference. (p<0.05). 4 Group A had better sealing ability than Group B, but there was statistically no significant difference. (p>0.05). 5. Group C had better sealing ability than Group D, but there was statistically no significant difference. (p>0.05). 6. As a result of observation under SEM, Smear layers were removed in Group A, B. but Smear layers were partially removed and smear plugs were remained in Group C, Smear layers were not removed in Group D. To be specially, Melting of smear layer were showed in Group C. 7. These results suggests that the laser has a potential in reducing the apical microleakage of obturated canals.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.7
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• pp.525-529
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• 1999

The influence of ambient gases on field emission performance of Mo-field emitter array(FEA) in the frit-sealing step of field emission display(FED) packaging process was investigated. Mo-tip FEA was mounted on the glass substrate having a surrounded frit(Ferro FX11-137) and fired at $415^{\circ}C$ in the ambient gases of air, $N_2$ and Ar. The Ar gas was proved to be most proper ambient among the used gases through evaluating the turn-on voltage and field emission current of the fired Mo-tip FEA devices. It was confirmed that the Mo surface fired in Ar ambient was less oxidized when compared with another ones annealed in air and Ar ambient by the AFM, XPS, AES and SIMS analysis. Finally, the 3.5 inch-sized Mo-tip FED, which was packaged using frit-sealing process in the Ar ambient, was proposed.