• Journal of Advanced Marine Engineering and Technology
• /
• v.27 no.6
• /
• pp.704-713
• /
• 2003

The effect of partial substitution of tungsten for molybdenum on the microstructure and corrosion resistance in 22Cr-5Ni-3Mo duplex stainless steel(DSS) aging heat treated in a temperature range of 600~$1000^{\circ}C$ has been investigated. Electrochemical tests were carried out for the evaluation of corrosion resistance. Aging treatment had hardly influenced the general corrosion resistance. With the increase of aging time, the pitting corrosion resistance of the DSS had decreased, After aging for 2min at 700~$900^{\circ}C$, the pitting potential of the 3Mo steel decreased remarkably, while that of the W-substituted steel hardly changed. During aging. the intermetallic $\sigma$ and secondary austenite ($\gamma_2$) phases were precipitated. and the pitting corrosion and intergranular corrosion resistance were significantly decreased after aging at 700~$750^{\circ}C$ for 10 h, which could be caused by the $\gamma_2$ formation. The ${\gamma}$$_2$ phase could affect the depletion of molybdenum and chromium in the $\gamma_2/\alpha and \gamma_2/\sigma$ boundaries.

• Geomechanics and Engineering
• /
• v.14 no.3
• /
• pp.241-246
• /
• 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.

• Geomechanics and Engineering
• /
• v.28 no.1
• /
• pp.1-10
• /
• 2022

In Korea, accidents related to the collapse of deteriorated aging reservoirs occur every year. The grouting method is generally applied to reinforce an aging reservoir. However, when using this method, different reinforcing effects appear depending on the ground conditions. Thus, new construction methods and materials capable of providing consistent reinforcing effects are required. In this study, the direct shear test (DST), model test, and simulation analysis were performed to evaluate the impact of surface stabilizers, generally used to reinforce roads, rivers, and slopes of roads, applied using surface curtain walls on aging reservoirs. The DST results indicate that when the surface stabilizer was mixed with in-situ soil, the increase in cohesion was the highest at a mixing ratio of 9%. No changes in the friction angle were evident; therefore, 9% was determined to be the optimal mixing ratio. In addition, the model test and simulation analysis showed that when 9% of the surface stabilizer was mixed and applied to the aging reservoir, the seepage quantity of water and the saturated area were reduced by approximately 42% and 73%, respectively. Moreover, the comprehensive analysis of results showed that the grouting method could be completely replaced by surface stabilizers applied through surface curtain walls because the technique could secure stability by decreasing the seepage in the aging reservoir.

• Journal of Korean Medical classics
• /
• v.27 no.2
• /
• pp.25-48
• /
• 2014

Objectives : This study aims to analyze the terms describing anti-aging effects in Dongeuibogam, and to propose the methodology for selecting medicinal herbs related to anti-aging effects. Methods : We considered aging or anti-aging theories by reviewing the major literature in korean medicine or traditional chinese medicine, and then we deduced the concepts describing anti-aging effects and the medicinal herbs for anti-aging effects. We investigated the medicinal herbs based on the terms describing anti-aging effects in Dongeuibogam and drew the methodology for selecting and classifying the medicinal herbs related to anti-aging. Results & Conclusions : The following conclusions could be drawn. 1. A set of causes and signs of aging in Dongeuibogam and a set of therapies for alleviating the aging signs in Chengumikbang, Yanglobongchinseo, and Nolohangeon was found. 2. Anti-aging effects should not be confused with disease treatments. Therefore, we defined the medical terms of anti-aging effects as "the terms expressing the effect of delaying or alleviating the subjective or objective signs of aging concretely". Based upon the terms of anti-aging effects, we defined the medicinal herbs for anti-aging effects as "the medicinal herbs whose effects are described in medical terms expressing the effects of delaying or alleviating the subjective or objective signs of aging concretely". 3. We considered Lycii Fructus, Asparagi Tuber in Dongeuibogam as examples of medicinal herbs whose effects are described in medical terms expressing anti-aging effects. It shows that we can select medicinal herbs for anti-aging effects by comparing the effects of 937 single therapies in Dongeuibogam to the terms describing anti-aging effects defined in this study. Futhermore, the results could be utilized as the basic materials of experimental study on anti-aging.

• The Journal of the Korea Contents Association
• /
• v.16 no.7
• /
• pp.100-111
• /
• 2016

This study analyzes targeting 584 senior citizens aged 65 and over in Gyeongsangnam-do to verify a mediated control effect of optimism and family support in stress and successful aging of the aged. Using SPSS Macro Way suggested by Preacher and Hayes. A study model is verified through a route model, and the verification of the study model is conducted in three stages. The first stage analyzes whether a control variable has a control effect in a relationship between predictor variable and standard variable, and the second stage confirms a relationship between predictor variable and mediated variable. In addition, the third stage confirms a mediated control effect. An analytical result is summarized as follows. First, as a result to verify a mediated effect between stress and successful aging, and optimism, it is confirmed that it supports a partially-mediated model. Second, as a result to verify a control effect of optimism and family support of successful aging, it is confirmed that everything has a control effect. Third, as a result to verify a mediated control effect of stress, optimism, successful aging, and family support, there is a mediated control effect. Based on these study results, practical undertone and future task are suggested, and a way to improve family support is presented for successful aging in advanced age.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.2
• /
• pp.241-243
• /
• 2001

• Korean Journal of Materials Research
• /
• v.26 no.5
• /
• pp.287-291
• /
• 2016

The effect of heat treatment on the microstructure and mechanical properties of cast Ti-6%Al-4%V alloy was investigated. Heat treatment of cast Ti-6Al-4V alloy was conducted by solution treatment at $950^{\circ}C$ for 30 min; this was followed by water quenching and then aging at $550^{\circ}C$ for 1 to 1440 min. The highest hardness of the heat-treated specimens was obtained by solution treatment and subsequent aging for 5 min due to precipitates of fine ${\alpha}$ that formed from retained ${\beta}$ phase. The tensile strength of this alloy increased without dramatic decrease of the ductility due to microstructural refinement resulting from the decomposition of ${\alpha}^{\prime}$ martensite into fine ${\alpha}$ and ${\beta}$ phases, and also due to the fine ${\alpha}$ phase formed from the retained ${\beta}$ phase by aging treatment for 5 min. In addition, this strengthening might be caused by the transformation induced plasticity (TRIP) effect, which is a strain-induced martensite transformation from the retained ${\beta}$ phase during deformation, and which occurs even after aging treatment at $550^{\circ}C$ for 5 min.

• Journal of Korean Traditional Oncology
• /
• v.20 no.1
• /
• pp.81-88
• /
• 2015

Generally, normal cells synthesize adenosine triphosphate (ATP) through oxidative phosphorylation in the mitochondria. However, they produce ATP through lactic acid fermentation on hypoxic condition. Interestingly, many cancer cells rely on aerobic glycolysis for ATP generation instead of mitochondrial oxidative phosphorylation, which is termed as "Warburg effect". According to results from recent researches on differences of cancer cell metabolism from normal cell metabolism and because chemotherapy to suppress rapidly growing cells, as a side effect of cancer treatment, can still target healthy cells, there is merit in the development of small-molecule inhibitors targeting metabolic enzymes such as pyruvate dehydrogenase kinase (PDHK), lactate dehydrogenase (LDH) and monocarboxylate transporter (MCT). For new anticancer therapy, in this review, we show recent advances in study on cancer cell metabolism and molecules targeting metabolic enzymes which are importantly associated with cancer metabolism for cancer therapy. Furthermore, we would also like to emphasize the necessity of development of molecules targeting metabolic enzymes using herbal medicines and their constituents for anticancer drugs.

• Journal of the Korean Society of Tobacco Science
• /
• v.26 no.1
• /
• pp.27-34
• /
• 2004

This study was carried out to examinate the effect of aging period on chromatic, chemical and organoleptic characteristics, and to evaluate of optimum aging period for each grade in flue-cured leaf tobacco. The leaf tobaccos were produced in 2000, and threshed, redried and packed in carton box under the current methods. Four grades of processed leaf(A3O, B1O, C1L and D3L) were stored during 24 months(May 10, 2001 to April 31, 2003) in warehouse of Chungju Leaf Tobacco Processing Factory. The leaf tobaccos were sampled at three month intervals for analysis of chromatic, chemical and organoleptic properties. Yellow(b), pH values and total sugar contents of four grades were significantly decreased during the aging. Filling values, tar, nicotine and CO contents of tobacco smoke, and puff number of cigarettes were not significantly changed during the aging. Positive correlation coefficients were significantly observed between taste and irritation of the calculated attributes from contents of volatile oil components in leaf tobacco and those of the panel sensory attributes. The ratio of maximum change in taste attribute was larger than that in irritation attribute during aging. The optimum aging periods estimated by taste for A3O, B1O, C1L and D3L were 17.8, 14.9, 10.8, and 9.8 months, respectively. The thin leaf(Primings and Cutters) undergo satisfactory aging earlier as compared to bodied leaf(Leaf and Tips). The results suggest that decrease of aging period for thin leaf from 18～21 to 9～12 months may be beneficial to save storage cost in flue-cured tobacco.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.440-446
• /
• 2018

This study examines the contrasting effects of an aging workforce on organizational innovation and the moderating role of age diversity. By utilizing a knowledge-based view, this study asserts that an aging workforce can contribute to organizational innovation to some degree due to accumulated firm-specific knowledge and experiences as well as various social networks within and outside the firm. On the contrary, as the portion of an aging workforce increases, the negative effect of the aging workforce on organizational innovation can overwhelm the positive effects because of the limitations of new knowledge creation. In addition, this study explores the effect of age diversity to moderate the relationship between aging workforce and organizational innovation.Empirical findings showed that an aging workforce and organizational innovation had an inverted-U relationship, and age diversity moderated this curvilinear relationship as this study predicted. These theoretical arguments and empirical findings highlight the necessity to explore the complex effects of an aging workforce on organizational innovation as well as additional factors influencing the relationship between aging workforce and firm innovation.