• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.3
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• pp.83-88
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• 2010

This study aimed to enhance the durability by distributing the stress concentration at the contact and increasing the mechanical characteristics, as well as by changing the surface shape for LIP in the low-pressure seal among oil seals installed to the power steering of automotive. Accordingly, results were derived from comparisons and reviews with oil seals under the existing mass production by carrying out the performance tests after designs and productions are done with the addition of embo shapes on the surface of LIP in the low-pressure seal. As a result of this study, it has been identified that the durability of oil seals with the addition of embo shapes was enhanced with higher radial force and less variation in the internal diameter for the LIP. In addition, it was seen that the sealing ability for those oil seals is superior to the existing oil seals as their rotational torque values are less than those of the existing oil seals.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.154-166
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• 2015

The in-core instrumentation measures core power distribution and coolant temperature in local regions of the core in pressurized water reactors. The installation types are distinguished by the designs of routing paths that exit either through reactor bottom mounted instrument nozzles or through reactor top mounted instrument nozzles. Although each type has unique advantages, it is generally known that top mounted design is more competitive with respect to emphasizing nuclear safety issues and ability to cope with severe accidents. The international nuclear vendors have provided various types of reactors with top mounted design. Nuclear power reactors in Korea, however, only have been designed to be applicable to the use of bottom mounted design, and it has been pointed out that the capabilities of Korean reactors against severe accidents should be further enhanced. The paper deals with technical issues on reactor internal and external design, in-core instrumentation, support assembly, sealing mechanism with nozzles, handling, and analytical issues in order to establish the ways of development.

• Restorative Dentistry and Endodontics
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• v.14 no.2
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• pp.31-37
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• 1989

The purpose of these study was to compare the sealing ability of a injection-molded thermoplasticized gutta-percha and silver amalgam as retroseal material in vitro. Sixty two upper and lower extracted human teeth with single root were randomly selected and instrumented in a conventional method with H-file. After instrumentation the root canal was obturated with gutta-percha by lateral condensation technique with AH26 and an apicoectomy was performed by beveling the root tip 45 angle. In the experimental group 1 and 2, a class I preparation was made and filled with silver amalgam or gutta-percha and in the experimental group 3 an apicoectomy only was performed. All specimens were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the canals were evaluated by califer. The results were as follows ; 1. The experimental group 1 displayed the smallest mean dye penetration as 0.45mm. 2. The experimental group 3 displayed the greatest mean dye penetration as 0.65mm. 3. There was the difference in dye penetration between each group, but the difference was not statistically significant(P>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.3 no.1
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• pp.33-39
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• 1976

The present in vitro study was undertaken to evaluate the initial marginal sealing ability of the sealant known as Nuva-Seal to seal cavity margins when used in conjunction with Adaptic and Nuva-Fil restorative materials. The results were as follows; 1. Where each Adaptic and Nuva-Fil restorative material was filled, showed the greatest degree of marginal leakage. 2. Where Adaptic and Nuva-Fil restorative materials were filled after acid etched surrrounding enamel surface adjoining the cavity margins, showed some degree of marginal leakage. 3. Where the Nuva-Seal was applied after acid etching a) to the cavity walls and the peripheral enamel surface adjoining the cavity margins, b) only to the surrounding enamel surface adjoining the cavity margins, and c) over the restorations and the peripheral enamel surface, showed complete absence of marginal leakage of Adaptic and Nuva-Fil restorative materials. 4. Where the Nuva-Seal was applied with the same methods as above, and restorations were placed on thermal stress also showed complete absence of marginal leakage of Adaptic and Nuva-Fil restorative materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.183-189
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• 2009

In this study, the growth diagnosis of root is analyzed through plant's auxanology point of view, and the inductive root barrier ability of panel type waterproofing method which is designed to deal with it, is confirmed positively through long term(2 years) mock-up test. Moreover, basic ideas for inductive root barrier design in joint is presented through this study. The experiment result for the root barrier of sealed A-type during 24 months, there were no damages found on the waterproofing layer. -urethane sealing material was used to apply for waterproofing of joint- for roots. As the result, it was confirmed that it is possible to maintain the root barrier of method through applying inductive root barrier design such as the installation of decreasing space of bearing power which considers the growth diagnosis of root, even if the root barrier was not secured.

• Journal of the Korean Vacuum Society
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• v.9 no.1
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• pp.7-15
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• 2000

An ECR-PECVD system with the characteristics of high ionization rat다 ability of plasma processing in a wide pressure range and deposition at low temperature was manufactured and characterized for the deposition of thin films. The system consists of a vacuum chamber, sample stage, vacuum gauge, vacuum pump, gas injection part, vacuum sealing valve, ECR source and a control part. The control of system is carried out by the microprocessor and the ROM program. We have investigated the vacuum characteristics of ECR-PECVD system, and also have diagnosed the characteristics of ECR microwave plasma by using the Langmuir probe. From the data of system and plasma characterization, we could confirmed the stability of pressure in the vacuum chamber according to the variation of gas flow rate and the effect of ion bombardment by the negative DC self bias voltage. The plasma density was increased with the increase of gas flow rate and ECR power. On the other hand, it was decreased with the increase of horizontal radius and distance between ECR source and probe. The calculated plasma densities were in the range of 49.7\times10^{11}\sim3.7\times10^{12}\textrm{cm}^{-3}$. It is also expected that we can estimate the thickness uniformity of film fabricated by the ECR-PECVD system from the distribution of the plasma density.

• Composites Research
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• v.35 no.6
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• pp.402-411
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• 2022

In this study, the channels-contained hybrid membranes have been fabricated through the incorporation of glass fibers and GO sheets (GO/glass fibers, GG), or a mixture of chitosan/GO (CS/GO/glass fibers, CGG), as hybrid membranes using in organic dye removal. The material properties are well investigated the terms in the morphological, chemical, crystal, and thermal characterizations for verifying interactions in their formed structure. These hybrid membranes have been fitted well in pseudo-second order and Langmuir models that are associated with chemical adsorption and a monolayer approach, respectively. The highest adsorption ability of methylene blue and methyl orange reached 59.40 mg/g and 229.07 mg/g (GG); and 287.47 mg/g and 252.91 mg/g (CGG), which is more enhanced than that of previous GO-based other adsorbents. Moreover, the dye separation on these membranes could be favorable to superb sealing and trapping dye molecules from water instead of only the dye connection occurring on their surface, regarding the physically sieving effect. The membranes can also be reused within two and three adsorbing-desorbing cycles on the GG and CGG ones, respectively. These membranes can become future adsorbents to be applied for wastewater treatment due to their structural features.

• Restorative Dentistry and Endodontics
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• v.36 no.5
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• pp.385-396
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• 2011

Objectives: This study evaluated the effects of adhesion variables such as the priming concepts of canal wall and the curing modes of adhesives on the sealing ability of a resin-based root canal filling system. Materials and Methods: Apical microleakage of the Resilon-RealSeal systems filled with 3 different combinations of adhesion variables was compared with the conventional gutta-percha filling using a dye penetration method. Experimental groups were SEDC, Resilon (Resilon Research LLC) filling with self-etch RealSeal (SybronEndo) primer and dual-cure RealSeal sealer; NELC, Resilon filling with no etching, Scotchbond Multi-Purpose (3M ESPE) primer application and light-curing adhesive; and TELC, Resilon filling with Scotchbond Multi-Purpose primer and adhesive used under total etch / wet bonding and lightcure protocols. GPCS, gutta-percha filling with conventional AH26 plus sealer, was the control group. Results: The median longitudinal dye penetration length of TELC was significantly shorter than those of GPCS and SEDC (Kruskal-Wallis test, p < 0.05). In the cross-sectional microleakage scores, TELC showed significant differences from other groups at 2 to 5 mm from the apical foramen (Kruskal-Wallis test, p < 0.05). Conclusions: When a resin-based root canal filling material was used, compared to the self-etching primer and the dual-cure sealer, the total etch/wet-bonding with primer and light-curing of adhesive showed improved apical sealing and was highly recommended.

• Proceedings of the KACD Conference
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• 2008.05a
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• pp.198-203
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• 2008

The purpose of this study was to compare the sealing abilities of four endodontic temporary restorative materials using a methylene blue dye penetration test under dynamic loading. Standardized access cavities were prepared in forty-four intact human permanent molar teeth, and the cavities were restored with Caviton, MD-Temp, IRM, or ZOE. After thermocycling, an intermittent load of 98 N at 1 Hz was applied for 1,000 cycles to the long axis of the functional cusp of each of the teeth, which were immersed in a 1% methylene blue solution. The teeth were split in half, and the linear depth of dye penetration was evaluated according to the criteria. The results were analyzed using one-way ANOVA (p = 0.05) and Duncan's multiple range test. The results demonstrated that Caviton and MD-Temp showed significantly lower microleakage than IRM and ZOE. It was concluded that Caviton and MD-Temp exhibited better sealing ability than IRM and ZOE under dynamic loading.

• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.385-392
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• 2005

The purpose of this study was to observe the effect of canal filling on the bacteria left in the dentinal tubules and to compare the sealing ability between Gutta-percha and Resilon. The bovine dentin block models were prepared E. faecalis was inoculated to dentin blocks and incubated. The dentin blocks were divided into 5 groups. Group 1 was the negative control. Group 2 was the positive control. Group 3 was filled with ZOE based sealer and Gutta-percha, Group 4 with resin based sealer and Gutta-percha, and Group 5 with resin based sealer and Resilon. After 24 hour, the blocks were incubated at $37^{\circ}C$ for 1, 2, 3 and 4 weeks on BHI agar plates. The internal dentin portion of the blocks was removed using ISO 027, 029, 031, 035 round burs and the dentin chips were incubated at $37^{\circ}C$ for 24 hour Following incubation, the optical density of the medium was measured. The data were statistically analysed using repeated measures ANOVA and one-way ANOVA. The results were as follows, 1. There. was statistically significant reduction in the number of E. faecalis of the group where dentinal tubules were completely sealed with nail varnish in comparison with the groups obturated with gutta-percha or resilon (p < 0.05). 2. In group 5, the number of E. faecalis in the dentinal tubules decreased significantly with time (p < 0.05). whereas in Group 3 and 4, there was no reduction in its number (p > 0.05). 3. Under the conditions of this experiment, E. faecalis survived up to 4 weeks after obturation with gutta-percha or resilon (p > 0.05).