• 한국안전학회지
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• 제21권2호
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• pp.107-113
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• 2006

Earthquake motion is one of the most significant influence factors on the slope stability. In this paper, an effective stress analysis with the elasto-plastic model was carried out to investigate the behavior of the slope stability subjected to the successive two strong earthquake motions, fore and main shock. The major influence of fore shock to the slope stability was considered as the existence of the residual excess pore water pressure. The paper presents the influence of the existence of the fore shock to slope stability using the numerical analyses. In conclusion, the excess pore pressure by the fore shock was not dissipated during the 7hrs of consolidation. By this residual excess pore water pressure, the factor of safety at the sliding face showed the minimum values, and the deformations of slope was large when compared with the case that considered the main shock only. Furthermore, the minimum of the factor of safety came out after the end of the earthquake motion.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.550-555
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• 2005

In vicinity of Seoul, there has been water service tunnel that classified into 1st grade facility by special act for the safety control of public structures and with providing capacity equals to $1,543{\times}10^3$(ton/day) and inner pressure equals to $2.5-3.5kg/cm^2$. In this research, site investigation and stability analysis for water tunnel caused by new construction of road tunnel were carried out. the ground near water tunnel were zoned into spatial area having similar geotechnical characteristics and estimating geotechnical properties for each area. The site for analysis consists of banded biotite gneiss, biotite schist and granite gneiss with spatial non-homogeneity, and for that reason weathering and fault zone were distributed with large scale. It's important thing to consider spatial ground zone and their geotechnical properties properly into stability analysis at design and construction stage. Also, using results of site investigation, stability of existing tunnel have been analyzed for Hydraulic Fracture/Jacking and deformation in detail.

• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.278-287
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• 2015

PURPOSE. The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS. Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study. One hundred five specimens were fabricated. For the color stability test, specimens were immersed in the coffee and green tee for 1 and 8 weeks. Color change was measured by spectrometer. Water sorption was tested after 1 and 8 weeks immersion in the water. For the test of cytotoxicity, cell viability assay was measured and cell attachment was analyzed by FE-SEM. RESULTS. All types of denture base resin showed color changes after 1 and 8 weeks immersion. However, there was no significant difference between denture base resins. All specimens showed significant color changes in the coffee than green tee. In water sorption test, thermoplastic acrylic resin showed lower values than conventional heat-polymerized acrylic resin and thermoplastic polyamide resin. Three types of denture base showed low cytotoxicity in cell viability assay. Thermoplastic acrylic resin showed the similar cell attachment but more stable attachment than conventional heat-polymerized acrylic resin. CONCLUSION. Thermoplastic acrylic resin for the non-metal clasp denture showed acceptable color stability, water sorption and cytotoxicity. To verify the long stability in the mouth, additional in vitro studies are needed.

• 한국축산식품학회지
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• 제39권4호
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• pp.623-631
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• 2019

Tetramethylpyrazine (TMP), an alkaloid rich in Ligusticum wallichii and fermented products, possesses multiple pharmacological activities in antioxidant, antiinflammatory, and antibacterial. This study aimed to investigate the effect of TMP (15 mg/L) on the physicochemical and gelation properties of rabbit myofibrillar proteins (MPs) with/without oxidative stress. Results showed that compared to the control, oxidative stress to MPs decreased free thiol content, gel yield, whiteness, water-holding capacity, bounder water, immobilized water, and endogenous tryptophan fluorescence intensity, but increased surface hydrophobicity, dityrosine content, and free water content (p<0.01). Without oxidative stress, MPs treated with TMP increased free thiol content, whiteness, and bound water, but decreased dityrosine content and free water (p<0.05). Under oxidative conditions, all parameters were conversely affected by TMP (p<0.01). The results suggest that TMP can be an antioxidant to decrease the concern on oxidative deterioration during meat processing and storage by improving the oxidative stability, water retention, and gel forming property of rabbit MPs.

• Geomechanics and Engineering
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• 제14권3호
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• pp.241-246
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• 2018

The displacement monitoring data series reconstruction method was developed under equal water level effects based on displacement monitoring data of concrete dams. A dam displacement variation equation was set up under the action of temperature and aging factors by optimized analysis techniques and then the dam displacement hydraulic pressure components can be separated. Through the dynamic adjustment of temperature and aging effect factors, the aging component isolation method of dam displacement was developed. Utilizing the isolated dam displacement aging components, the dam stability model was established. Then, the dam stability criterion was put forward based on convergence and divergence of dam displacement aging components and catastrophe theory. The validity of the proposed method was finally verified combined with the case study.

• Journal of the Korean Wood Science and Technology
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• 제24권4호
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• pp.40-46
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• 1996

It is well-known fact that dimensional stability of wood is greatly enhanced by acetylation of wood. This dimensional stability results from bulking of the reacted acetate within the cell wall, which reduces further swelling when the modified woods corne into contact with water or water vapor. The purpose of this research was to determine the water absorption and dimensional stability of the acetylated solid wood in liquid water and in humidity tests. Radiata pine, Siberian larch, and Japanese larch were acetylated. Antiswelling efficiency(ASE) and equilibrium moisture content(EMC) of acetylated wood, at 95% RH and $20^{\circ}C$ after 4weeks, was quite dependent on WPG, but was not dependent on species.

• Journal of Forest and Environmental Science
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• 제29권2호
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• pp.109-115
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• 2013

Fast-grown wood generally contains a high proportion of juvenile wood that results in inferior dimensional stability and durability against biological deteriorations. In the present research, the Acacia mangium wood from plantation forests in Vietnam was treated with high temperature in air. The effects of heat treatment on physical properties of Acacia mangium wood, including mass loss (ML), water absorption (WA), water-repellent effectiveness (WRE) and anti-swelling efficiency (ASE) were examined. The results showed that the dimensional stability and the water-repellent effectiveness are increased by about 15-46% and 8-18%, respectively. However, the mass and dimension of wood are decreased. The results also indicated that both treatment temperature and treatment duration significantly affect the wood properties of Acacia mangium. It is thus concluded that heat treatment demonstrates an interesting potential to improve the wood quality of Acacia mangium for solid timber products. This technology provides an environmentally safe method of protecting sustainable common woods to give a new generation of value-added biomaterials with increased stability without the use of toxic chemicals.

• Geomechanics and Engineering
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• 제13권3호
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• pp.447-458
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• 2017

This study proposes a sensitivity analysis method for slope stability based on the least squares support vector machine (LS-SVM) to examine the influencing factors of slope stability. The method uses LS-SVM as an algorithm for machine learning. An appropriate training dataset is established according to the slope characteristics, and a testing dataset is designed orthogonally. Results of the testing data in the experiment design are calculated after training using the LS-SVM model. The sensitivity of the slope stability of each factor is examined via gray correlation analysis. The results are consistent with those of the traditional Bishop analysis and can be used as a reference for optimizing slope design.

• 약학회지
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• 제25권1호
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• pp.37-42
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• 1981

Penicillin derivatives have a stability problem by hydrolysis of their .betha.-lactam ring. At high temperature, crystal water is released from penicillin derivatives, especially ampicillin trihydrate and concerns itself in hydrolysis. Penicillin derivatives having crystal water show different crystal states and different stability according to the variation of different condition on the process of manufacturing. The stability of ampicillin trihydrate in solid states was determined. Physico-pharmaceutical properties of this compound were determined by using IR spectra, X-ray powder diffraction and differential thermal analysis (DTA).

• 전기의세계
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• 제16권2호
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• pp.17-21
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• 1967

In reactor operation, it is widely known that the absolute stability may not exist for multiple feedback paths even though the single lumped negative temperature coefficient feedback case is clearly stable at all frequencies above those creating xenon poisoning effects. However, interesting and useful stability information may be obtained from a two-path temperature coefficient feedback which can be represented in a water-cooled, water-moderated hetergeneous reactor. In this paper, the outline of an operating stability of a reactor having two-path temperature coefficient feedback is analyzed and described neglecting poison effects.