• Magazine of RCR
• /
• v.18 no.3
• /
• pp.24-28
• /
• 2023

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.161-161
• /
• 2016

연질 폴리염화비닐 졸 (PVC Sol) 코팅의 물리적, 화학적 내구성을 향상시키기 위하여 표면 개질된 무기물 입자를 첨가시킨 PVC 코팅을 형성하였고 그 특성을 분석하였다. 이를 통해 다양한 분야에 적용할 수 있는 고내구성 PVC sol 코팅공정을 확립하였다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.4
• /
• pp.1095-1104
• /
• 2014

This paper presents the results of experimental work on both strength characteristics and durability of concrete or mortar having 50% ground granulate blastfurnace slag(GBS) with different fineness levels (4,450, 6,000 and $8,000cm^2/g$). Compressive and split tensile strength test results indicated that the concrete with a higher fineness level of GBS exhibited a better strength development due to the acceleration of latent hydraulic property at the later curing stage compared with ordinary portland cement concrete. Meanwhile, it was found that a higher fineness level of GBS showed some negative effects on the resistance against freezing-thawing action. However, incorporation of GBS to concrete, irrespective of fineness levels, significantly enhanced the chloride ions penetration resistance. The resistance against sulfate attack of mortar with GBS was greatly dependent on the attacking sources from sulfate environments.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.147.1-147.1
• /
• 2014

대부분의 반도체공정은 플라즈마 기술을 활용함에 따라서 진공공정장비 부품은 플라즈마 이온, 활성기체, 고온 공정에 노출 된다. 또한 장시간 플라즈마 공정에 노출이 되면서 부품 내구성이 떨어지기 때문에 내플라즈마성이 강한 재료를 코팅하여 사용하고 있다. 하지만 코팅재료의 종류, 코팅방법에 따라서 내부식성이 각각 다르고 장시간 설비 활용 시 코팅재료가 부식되어 공정특성이 변함에도 불구하고 현재 Fault Detection and Classification (FDC) 기술에서는 모니터링이 어려운 문제점이 있다. 본 연구에서는 공정특성을 플라즈마 임피던스 변수로 모니터링 하여 코팅부품의 상태에 따른 플라즈마 공정변화를 모니터링 가능한 신규 플라즈마 공정모사용 평가 장비를 소개하고자한다.

• Journal of the Society of Disaster Information
• /
• v.15 no.3
• /
• pp.450-458
• /
• 2019

Purpose: The purpose of this study is to develop a new sewage bay that has removed its previous problems and verify the excellence of the maintainability of the new sewage bay. Method: The fluid characteristics in the developed sewage bay was analysed with computer simulation tool(COMSOL MultiphysicsTM ver. 3.2 ; COMSOL) and clarified the problems of the existing sewage bay. In addition, the durability of the newly developed sewage bay was verified by the long-term usability testing. Results: As a result of the simulation of a blocked drainage trap, an whirlpool and blockage did not occurred at the flow rate of 0.6m/sec, and we verified that switch device of drain trap was in good condition durably with 6 months long-term usability test. Conclusion: In this study, a newly advanced sewage bay was developed that solved the problems of the existing sewage bay structure. With the fluid simulation and the long-term usability tests, the excellence of the maintenance ability of the newly developed sewage bay was proved.

• Applied Chemistry for Engineering
• /
• v.28 no.2
• /
• pp.158-164
• /
• 2017

In this study, the reaction activity and XRD, BET, and Raman analysis were performed to verify $NH_3$-SCR reaction characteristics of various commercial SCR catalysts. It can be seen that the reaction rate of each commercial SCR catalyst increased linearly with increasing the vanadium content (1.3-5.4 wt%). In addition, through the above analysis, it was possible to confirm that the addition of WOx in the catalyst increased the Turn over frequency (TOF) within the range where the VOx surface density was more than 8.1 and the crystalloid VOx was not formed through the surface structure analysis. $SO_2$ durability tended to decrease with increasing the vanadium content, and the durability increased the most when W and Si were added.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.2
• /
• pp.46-52
• /
• 2017

Recently durability design based on deterministic or probabilistic method has been attempted since service life evaluation in RC(Reinforced Concrete) structure exposed to chloride attack is important. The deterministic durability design contains a reasonable method with time effect on surface chloride content and diffusion coefficient, however the probabilistic design procedure has no consideration of time effect on both. In the paper, a technique on PDF(Probability of Durability Failure) evaluation is proposed considering time effect on diffusion and surface chloride content through equivalent surface chloride content which has same induced chloride content within a given period and cover depth. With varying period to built-up from 10 to 30 years and maximum surface chloride content from $5.0kg/m^3$ to $10.0kg/m^3$, the changing PDF and the related service life are derived. The proposed method can be reasonably applied to actual durability design with preventing conservative design parameters and considering the same analysis conditions of the deterministic method.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.4
• /
• pp.53-59
• /
• 2012

In this study, strength and durability of a geo-polymer grout material(HIT) was investigated through unconfined compression strength tests(UCS)), scanning electron microscope(SEM), elution tests, and surface observations. UCS tests showed high initial strength and rapid continuous strength increments when compared to labile wasser glass(LW) and space grouting rocket system (SGR) grout materials, which showed strength reduction after 28 days. The higher strength was also reflected in SEM results which showed calcium silicate hydroxide(C-S-H) gels of the dense hydrate range, indicating higher strength and durability. Additionally, elution tests and grout surface observations showed HIT was in good condition and the decrease in weight was minor when under water for six months. LW and SGR showed the grout surface to be constricted and lower durability due to higher weight increase. These results and observations show HIT to be better suited for coastal structural applications than LW and SGR in long terms of strength and durability.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.6
• /
• pp.537-546
• /
• 2010

This research work contributed to a study for the procedure and methodology to assess the fatigue durability for a composite torque link of helicopter landing gear, which was newly developed and fabricated by the resin transfer moulding technique to interchange with metal component. The simulated load spectrum anticipated to be applied to the torque link during its operation life was generated using an advanced method of probabilistic random process, and the fatigue durability was evaluated by the strength degradation approach on the basis of material test data. The full scale fatigue test was also performed and compared with the analysis results.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.301-302
• /
• 2009

Uncertainties in carbonation process of concrete structures are treated by probability-based durability analysis for carbonation using Monte Carlo simulation technique. The results requires the minimum cover thickness of 53mm for 10% of corrosion probability under 4mm/$year^{0.5}$ of carbonation coefficient. The more researches on statistical properties of design variables may give reliable durability analysis/design methods for carbonation of concrete structures.