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Fluid Solid Coupling Analysis of Large Underground Oil Storage Caverns in Containment of Groundwater
Yang Shang-Yang,Li Shu-Cai,Xue Yi-Guo,Zhang Qing-Song 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.11
Triaxial compression tests had been performed to determine the properties of the rock mass around unlining underground crude oil a storage cavern which was the first one in China. The execution situation of the tunnel project and the seepage law of groundwater were taken into account. The stress and the seepage field around the tunnel in different working states were simulated by applying Comsol around a underground crude oil storage caverns. According to the test results, it was found that the excavation process may arise the local damage. The extension of the loose zone induced by excavation ranged from 0 to 15.6 m, depending on the buried depth of the caverns. According to numerical simulation results, the crown settlement and stress concentration was depended on the buried depth and the water pressure distribution after excavation of the main cavity. This research results can provide the reference for analysis on the stability of the underground cavities under low stress level and on the water sealed underground petroleum storage rock caverns.
Antibacterial Efficacy of Dental Sealant Containing Phytoncide
Song-Yi Yang,Myung-Jin Lee 한국치위생과학회 2023 치위생과학회지 Vol.23 No.4
Background: Dental caries prevention is a key research focus in dentistry, requiring advancements in the formulation of dental sealants. This study investigated the physical and antibacterial attributes of dental sealant enriched with phytoncide. Methods: Phytoncide was mixed with a commercially available dental sealant (Clinpro) at concentrations of 0 (control), 1.5%, 3%, and 4.5% by weight (wt%). The flexural strength, curing depth, and wettability of the dental sealant were measured. Antibacterial properties against Streptococcus mutans were evaluated through the enumeration of colony-forming units. Statistical analyses employed one-way variance analysis followed by Tukey’s test (p<0.05). Results: The dental sealant containing 3% phytoncide showed no significant difference in flexural strength and curing depth compared with that in the control group (p>0.05). The flexural strength and curing depth decreased with increasing phytoncide content and significantly differed in sealant containing 4.5 wt% phytoncide (p<0.05). Wettability did not differ between the experimental and control groups (p>0.05). The antibacterial properties of the sealant containing 1.5% phytoncide were the same as those of the control group (p>0.05). The bacterial viability was significantly reduced in groups containing 3% and 4.5% phytoncide compared with that in the control group (p<0.05). Conclusion: Dental sealants incorporating phytoncide have a promising potential as antibacterial dental materials.
Yang Shang-Yang,Li Shu-Cai,Xue Yi-Guo,Zhang Qing-Song 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.10
Triaxial compression tests had been performed to determine the properties of the surrounding rock. The displacement and stress of surrounding rock had been analyzed according to Silin 2 at Yungui railway under three kinds of conditions: the initial state, excavation without supporting , and supporting after excavation. Plane strain FEM was established to analyze the stability of the surrounding rock. Contrasted the monitor measuring data, the results showed that the most unfavorable position in the tunnel was found at the ridge side of the arch, and the implementation of support afforded to ensure the stability of surrounding rock, and the design of the early support approach had the ability to meet the safety requirements. The results had certain significance for understanding the mechanical behavior of shallow tunnel in unsymmetrical strata. tunnel, mechanical behaviour, numerical simulation, deformation, stability.
Antibacterial Effects of Tea Tree Oil and Mastic Oil to Streptococcus mutans
Song-Yi Yang,So-Hyun Lee,On-Bi Park,Hee-Rang An,Yeong-Hyeon Yu,Eun-Bi Hong,Kyung-Hee Kang,Hwa-Soo Koong 한국치위생과학회 2023 치위생과학회지 Vol.23 No.1
Background: Tea tree oil has antiviral, antimicrobial and antifungal effects and Mastic oil has antifungal and anticancer effects. For synergistic effects of oils, blending oil containing a mixture of two to three oils is recommended. This study aimed to determine the antibacterial effects of Tea tree oil, Mastic oil, and Blending oil containing the two oils in a mixture, to verify and suggest the potential use of these oils as a substance to prevent dental caries.Methods: Tea tree oil, Mastic oil, and Blending oil with a 1:1 blend of the two oils were diluted in liquid medium to 0% (negative control), 0.5%, 1.0%, and 2.0%. Streptococcus mutans was applied to each experimental group of the three diluted oils and after 8 h culture, the optical density (OD) was measured and the growth inhibition rate for S. mutans was estimated.Results: Tea tree oil had significantly low OD values across all concentrations (p<0.05) without significant variation among different concentrations (p>0.05). Mastic oil did not significantly vary in OD compared to the negative control across all concentrations (p>0.05) without significant variation among different concentrations (p>0.05). Blending oil, compared to the negative control, did not significantly vary in OD at 0.5% (p>0.05) but significant variation was found as the concentration increased (p<0.05). Additionally, for Tea tree oil and Mastic oil, the growth inhibition rate showed no significant variation according to concentration (p>0.05), whereas for Blending oil, the growth inhibition rate for S. mutans showed a significant difference at 1.0% (p<0.05) and at higher concentrations. Conclusion: Blending oil containing a Tea tree oil and Mastic oil demonstrated a significant growth inhibition effect on S. mutans from the concentration of 1.0%, which suggested its potential use as an effective antibacterial agent for dental caries.
양송이 ( Song Yi Yang ),오정민 ( Jeong Min Oh ),송다혜 ( Da Hye Song ),송보람 ( Bo Ram Song ),강명진 ( Myung Jin Kang ),이명선 ( Myung Sun Lee ),손가연 ( Ga Yeon Son ),오상환 ( Sang Hwan Oh ) 한국치위생학회(구 한국치위생교육학회) 2014 한국치위생학회지 Vol.14 No.4
Objectives : Latex gloves hygiene is the most effective method to prevent infection of microorganisms and to reduce the incidence of cross infections. The aim of this study was to compare the bacteria reduction ratio of cleansing with water, liquid soap and alcohol gauze. Methods : The left side glove was the control group and the right side was the experimental group. The experimental group washed hand with water, soap, and alcohol gauze. The hand plate was inoculated by the hand and inoculated for 24 hours in 35℃. Results : Washing with water showed that CFU of control group was 1116.9 and that of experimental group was 302.8. Hand washing by water reduced 74.3% of bacteria. Liquid soap revealed that CFU of control group was 619.9 and that of experimental group was 8.3. Hand washing by liquid soap reduced 97.5% of bacteria. Alcohol gauze included 875.2 CFU in control group and 5.8 CFU in experimental group. Washing by alcohol gauze reduced 99.5% of bacteria. Conclusions : Based on the results, the most effective latex gloves cleansing method was recommended as the standardized hand washing with the liquid hand soap and alcohol gauze. The results can be used to improve training strategies for enhancing glove hygiene practice in dental clinic.