• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.21-24
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• 1978

This study was conducted to find out the co-operative effect of antioxidants (butyl hydroxy anisol, dibutyl hydroxy toluene, propyl gallate, dl-$\alpha$-tocopherol) and organic acid (citric acid, tartaric acid, succinic acid) on the stability of soybean oil by active oxygen method. The results obtained were summarized as follows: 1. When antioxidants and organic acid were used together, the antioxidants activity was more strong than antioxidants were used only. 2. The co-operative effect of citric acid for antioxydants was the strongest whereas succinic acid was the weakest. 3. The co-operative effect of phenolic antioxydants for organic acid was more strong than dl-$\alpha$-tocopherol.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.192-199
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• 2003

Trimethylglycine, commonly named betaine, is the most simple amphoteric molecule. It is completely vegetal (1,2), as it is produced in the sugar industry by industrial chromatography of molasses. While abundantly used in foods and diet supplements, many interesting applications in cosmetics have recently been investigated, like its capability to increase the volume and stability of foams in surfactant solutions. For its special chemical structure (it is the internal salt of a weak acid and a strong alkali) trimethylglycine is a solvent and buffering agent for strong acids and Lewis' acids. It allows to improve the efficiency of $\alpha$- and $\beta$-hydroxy acids in increasing the physiological rate of epidermal cell renewal, while keeping a low skin-irritation level. In oral care cosmetics, it acts as a mucous membrane protectant (3). For its special water co-ordination capability, its solubilising power, polymer swelling capability, after-feel improvement in hair products, skin moisturization and elasticity enhancing properties, trimethylglycine provides unusual characteristics to many products intended for skin maintenance (4).(omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.413-413
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• 2012

Lead sulfide (PbS) Colloidal quantum dots (CQDs) are promising material for the photovoltaic device due to its various outstanding properties such as tunable band-gap, solution processability, and infrared absorption. More importantly, PbS CQDs have large exciton Bohr radius of 20 nm due to the uniquely large dielectric constants that result in the strong quantum confinement. To exploit desirable properties in photovoltaic device, it is essential to fabricate a device exhibiting stable performance. Unfortunately, the performance of PbS NQDs based Schottky solar cell is considerably degraded according to the exposure in the air. The air-exposed degradation originates on the oxidation of interface between PbS NQDS layer and metal electrode. Therefore, it is necessary to enhance the stability of Schottky junction device by inserting a passivation layer. We investigate the effect of insertion of passivation layer on the performance of Schottky junction solar cells using PbS NQDs with band-gap of 1.3 eV. Schottky solar cell is the simple photovoltaic device with junction between semiconducting layer and metal electrode which a significant built-in-potential is established due to the workfunction difference between two materials. Although the device without passivation layer significantly degraded in several hours, considerable enhancement of stability can be obtained by inserting the very thin LiF layer (<1 nm) as a passivation layer. In this study, LiF layer is inserted between PbS NQDs layer and metal as an interface passivation layer. From the results, we can conclude that employment of very thin LiF layer is effective to enhance the stability of Schottky junction solar cells. We believe that this passivation layer is applicable not only to the PbS NQDs based solar cell, but also the various NQDs materials in order to enhance the stability of the device.

• Korean Journal of Social Welfare
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• v.54
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• pp.321-345
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• 2003

Aggregate income stability depends heavily on labor market institutions that stabilize or de-stabilize earnings. But, with the expansion of sate welfare programmes, public income transfers are also important sources of income stability for individual and families. Moreover, income stability is determinant factor of individual and family well being, there are another strategies of income stability in society. Family-based and community-based strategies are particularly important. Accordingly, the distribution of income stability in a given society depends on such institutional arrangements as market, family, state, and community. The purpose of this study is to analyse the income stabilizing role of family, state, and community. I found that stabilizing effect of the family and community was very strong in Korea. When institutional features of labor market and the state leave individuals exposed to market risk, they may be respond by relying more on family-based or community-based strategies of income stabilization. But, I can't deny the possibility of an inadequacy of these strategies in according to the rapid changes of family structures and informal networks. Therefore, state-based strategies of income stabilization should be more strengthened in Korea.

• Korea journal of population studies
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• v.29 no.1
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• pp.71-95
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• 2006

This study aimed at identifying the relationship between marital satisfaction and marital stability, with primary focus on the effect of double sexual standards on their relationship. Data from 370 married women of community and culture centers in Daegu Metropolitan area were analyzed through multi-step multiple regressions. Findings indicated that communication and intimacy were positively related to marital satisfaction, which showed strong effect on marital stability, and that double sexual standard weakened the relationship between marital satisfaction and stability. Relationship between sexual satisfaction and marital satisfaction were not statistically significant in the sample of married women. Construction of comprehensive and systemic theoretical model on marital stability was suggested for further study.

• Wind and Structures
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• v.25 no.6
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• pp.507-535
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• 2017

In the strong wind shutdown state, the blade position significantly affects the streaming behavior and stability performance of wind turbine towers. By selecting the 3M horizontal axis wind turbine independently developed by Nanjing University of Aeronautics and Astronautics as the research object, the CFD method was adopted to simulate the flow field of the tower-blade system at eight shutdown positions within a single rotation period of blades. The effectiveness of the simulation method was validated by comparing the simulation results with standard curves. In addition, the dynamic property, aerostatic response, buckling stability and ultimate bearing capacity of the wind turbine system at different shutdown positions were calculated by using the finite element method. On this basis, the influence regularity of blade shutdown position on the wind-induced response and stability performance of wind turbine systems was derived, with the most unfavorable working conditions of wind-induced buckling failure of this type of wind turbines concluded. The research results implied that within a rotation period of the wind turbine blade, when the blade completely overlaps the tower (Working condition 1), the aerodynamic performance of the system is the poorest while the aerostatic response is relatively small. Since the influence of the structure's geometrical nonlinearity on the system wind-induced response is small, the maximum displacement only has a discrepancy of 0.04. With the blade rotating clockwise, its wind-induced stability performance presents a variation tendency of first-increase-then-decrease. Under Working condition 3, the critical instability wind speed reaches its maximum value, while the critical instability wind speed under Working condition 6 is the smallest. At the same time, the coupling effect between tower and blade leads to a reverse effect which can significantly improve the ultimate bearing capacity of the system. With the reduction of the area of tower shielded by blades, this reverse effect becomes more obvious.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.155-161
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• 2021

This study was conducted to estimate the effect of different cutting lengths on fermentation characteristics and aerobic stability of whole crop rice (WCR) silage. The WCR was harvested at the yellow ripe stage (43.7%, DM), and then cut at 5 (R05), 10 (R10), and 20 cm (R20) of the theoretical length of cut with no cut WCR (R60). Each forage was ensiled into 20 L mini bucket silo (5 kg) for 150 days in quadruplicates. The cutting lengths were not affected the chemical compositions of WCR silage (p > 0.05). The pH (p < 0.001) and concentration of ammonia-N (p = 0.022) in WCR silage were increased linearly with the increase of cutting length. The concentration of lactate had quadratic effect (p = 0.007), which was highest in R20 silage (p < 0.05). The concentration of acetate was increased linearly (p = 0.014), but the concentration of butyrate was decreased linearly (p = 0.033). The lactic acid bacteria count was decreased linearly (p = 0.017), and yeast count had quadratic effect (p = 0.009), which was the highest in R20 silage (p < 0.05). Aerobic stability had strong quadratic effect (p < 0.001), which was the highest in R20 silage (p < 0.05). In conclusion, R60 silage had highest pH by a linear increase of ammonia-N concentration and led to low aerobic stability. While R20 silage had the lowest pH by high lactate concentration and led to high aerobic stability.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.118-130
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• 2023

Decay or large cavities inside trees are the main causes of trees overturning and broken branches, and structurally weakened trees are more vulnerable to strong winds and heavy snowfall. Recently, as strong winds and typhoons increase due to climate change, the damage to human life and property due to trees overturning continues to increase, and cultural assets are in a similar situation. In particular, old big trees are structurally vulnerable to external shocks such as strong winds and heavy snowfall. This study was aimed at providing a scientific basis for preventive protection measures by conducting a structural stability diagnosis of seven retusa fringe trees designated as natural monuments. For the structural stability diagnosis, tree risk assessment and internal tree defect measurements were performed. As a result of the tree risk assessment, the Retusa Fringe Trees in Sinjeon-ri, Yangsan and Gwangyangeupsu had the highest risk of broken branches due to weak branch attachment strength. As a result of the diagnosis of internal defects of cross sections of measured trees, there were suspected cavities or severe decay in all except two trees of the population of Retusa Fringe Trees in Pyeongji-ri. Natural disasters due to climate change are increasing, and the scale is getting larger, so it is very important to preemptively manage large old trees through scientific structural safety diagnosis to manage trees that are vulnerable to environmental changes.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.475-488
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• 1988

Certain malocclusion are associated with specific "facial type," and it is important for the clinician to classify the common facial characteristic of each patient. Because the reaction to treatment mechanics and the stability of the denture is depended upon the analysis of the facial pattern. Basically, there are 3 district facial types or patterns under which almost all malocclusion can be classified. 1. mesofacial is the most average growth. 2. brachyfacial which is a horizontal growth pattern has a week muscle, with dental arch, deep bite. 3. dolichofacial which is a vertical growth pattern has a strong muscle, narrow dental arch, open bite. Brachyfacial pattern show a resistant to mandibular rotation during treatment can accept a more protrusive denture and are prominantly nonextraction, whereas dolichofacial patterns tend to open during treatment require a more retracted denture in order to assure post-treatment stability. Brachyfacial pattern would better treat to use extrusive force system, whereas dolichofacial pattern treat to use intrusive force system with head gear and intermaxillary elastics.

• International Journal of Control, Automation, and Systems
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• v.5 no.6
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• pp.691-700
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• 2007

This paper proposes a simple but effective design method of PID control using a numerical optimization method. In order to achieve both stability and performance, gain and phase margins and performance indices of step response directly compose of the cost function. Hence, the proposed approach is a multiobjective optimization problem. The main effectiveness of this approach results from the strong capability of the used optimization method. A one-dimensional example concerning gain margin illustrates the practical applicability of the optimization method. The present approach has many degrees of freedom in controller design by only adjusting related weight constants. The attained PID controller is compared with Wang#s and Ho#s methods, IAE, and ISE for a high-order process, and the simulation result for various design targets shows that the proposed approach achieves desired time-domain performance with a guarantee of frequency-domain stability.