• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.137-146
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• 2002

Geomembrane, compacted clay liner, and geosynthetic clay liner (GCL) are widely used to prevent leachate from leaking to adjacent geo-environment at a municipal solid waste (MSW) landfill. Interface shear strength between GCL and geomembrane installed at a landfill side slope is important properties for the safe design of side liner or final cover systems. The interface shear strength between two geosynthetics was estimated by a large direct shear test in this study. The shear strength was evaluated by the Mohr-Coulomb failure criterion. The effects of normal stress, hydration or dry condition, and a hydration method were investigated. The test results show that the interface shear strength and shear behavior varied depending up on the level of normal stress, the type of geosynthetic combinations, and a hydration method. When GCLs were sheared after being hydrated under 6kPa loading, the results were consistent with those published by other researchers. Summaries of friction angles, normal stress and hydration condition is presented. These friction angles could be used as a reference value at a site where similar geosynthetics are installed.

• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.79-89
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• 2002

Various geosynthetics used as liners or protection layers are installed in the solid waste landfills. The interface shear strength between geosynthetics installed at the slope of the landfill is a very important variable for the safe design of the bottom and cover systems in the solid waste landfills. The interface shear strength between Geomembrane and Geotexile is estimated by a large direct shear test in this study, The effects of normal stress, water existing between geosynthetics and surface condition of Geomembrae, i.e. smooth or textured, were investigated. The test results show that the effect varied depending on the level of normal stress and the type of geosynthetic combinations. The shear strength was evaluated by the Mohr-Coulomb failure criterion in this research. The shear strength parameters obtained from tests considering the site specific conditions such as normal stress, dry or wet, and surface condition of geosynthetic should be applied to the design of geosynthetics installed at the slope of the landfill to construct a safe solid waste landfill.

• The Korea Journal of Herbology
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• v.23 no.4
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• pp.71-79
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• 2008

Objectives: SimJeok-Hwan(CP, Cardiotonic Pills) was made to treat patients with coronary arteriosclerosis, angina pectoris and hyperlipidemia. This study was designed to investigate the effects of CP on Proliferation rates neuroglia cells and protective effect of CP against oxidative stress, and also investigate the effects on regional Cerebral Blood Flow(rCBF) in normal rats. Methods: In this experiment, effects of CP on proliferation rates of neuroglia cells were measured using modified MTT methods. Oxidative stress was induced by treatment with 200 mM of hydrogen peroxide for 2 hr. rCBF and MABP were measured using Laser doppler flowmeter. Results: Treatment with CP elevated proliferation rates in C6 cells. In addition, CP protected cell death of C6 cells induced by oxidative stress. In results, rCBF was elevated by treatment with CP in normal rats. But, Mean Arterial Blood Pressure(MABP) did not affected by CP. In addition, the elevation of rCBF was blacked by pre-treatment with 1 mg/kg of indomethacin effectively. On the other hand, pre-treatment with 0.01 mg/kg of methylene blue did not affect rCBF level in normal rats. Conclusions: In conclusion, these results suggest that CP can act as anti-oxidant to protect neuroglia cells and also suggest that CP can elevate rCBF, which are involved in cyclooxygenase pathway.

• Journal of the Semiconductor & Display Technology
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• v.3 no.2
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• pp.35-40
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• 2004

The total relaxed stress in annealing and the thermal strain/stress were obtained from the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI). The residual stress fields in case of both single and film / substrate systems were modeled using the thermo-elastic theory and the relationship between relaxed stresses and displacements. We mapped the surface residual stress fields on the indented bulk Cu and the 0.5 $\mu\textrm{m}$ Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -1.7 GPa to 700 MPa and -800 GPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI...

• International Journal of Safety
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• v.1 no.1
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• pp.36-42
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• 2002

This paper is aimed at predicting the life of rubber insulating gloves under normal operating stresses from relatively rapid test performed at higher stresses. Specimens of rubber insulating gloves are subject to multiple stress conditions, i.e. combined electrical and thermal stresses. Two modes of electrical stress, step voltage stress and constant voltage stress are used in specimen aging. There are two types of test for electrical stress in this experiment: the one is Breakdown Voltage (BDV) test under step voltage stress and thermal stress and the other is lifetime test under constant voltage stress and temperature stress. The ac breakdown voltage defined as the break-down point of insulation that leakage current excesses a limit value, l0mA in this experiment, is determined. Because the very high variability of aging data requires the application of statistical model, Weibull distribution is used to represent the failure times as the straight line on Weibull probability paper. Weibull parameters are deter-mined by three statistical methods i.e. maximum likelihood method, graphical method and least squares method, which employ SAS package, Weibull probability paper and FORTRAN, respectively. Two chosen models for predicting the life under simultaneous electrical and thermal stresses are inverse power model and exponential model. And the constants of life equation for multistress aging are calculated using numerical method, such as Gauss Jordan method etc.. The completion of life equation enables to estimate the life at normal stress based on the data collected from accelerated aging test. Also the comparison of the calculated lifetimes between the inverse power model and the exponential model is carried out. And the lifetimes calculated by three statistical methods with lower voltage than test voltage are compared. The results obtained from the suggested experimental method are presented and discussed.

• Korean Journal of Community Nutrition
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• v.14 no.2
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• pp.175-181
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• 2009

The purpose of this study was to investigate the relationships of stress, depression, binge eating and food behavior of high school girls with their degree of BMI. One hundred twenty high school girls from the Seoul metropolitan area participated in this study. Self-administrated questionnaires to search for degree of stress, depression, binge eating, and food behavior were distributed. Anthropometric assessment was carried out to calculate the body mass index(BMI). The results are as follows: The mean of age and BMI of the subjects were $17.6{\pm}0.6$ years and $21.0{\pm}2.9kg/m^2$(ranged from 15.4 to $31.7kg/m^2$), respectively. 16.7%, 65.8% and 17.5% of the subjects were classified as under weight, normal weight and overweight, respectively. The average scores of stress, depression and binge eating were $124.9{\pm}31.4$, $15.2{\pm}9.8$, $29.5{\pm}7.8$ points, respectively. The food behavior score was $11.5{\pm}2.4$ points. Their degree of stress, depression, binge eating was significantly higher in overweight high school girls compared to underweight or normal weight high school girls. There were significant correlations of BMI with stress(p<0.05), depression(p<0.001), and binge eating(p<0.01). Also there were significant correlations of food behavior with stress(p<0.05), depression(p<0.05) and binge eating(p<0.001). These results indicate that the high school girls who have higher BMI seem to have more stress, depression, and binge eating habits. Also the high school girls who have more stress, depression and binge eating habits have poor food behaviors. Therefore proper control of emotions is required to maintain desirable food behaviors in high school girls.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.260-271
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• 1992

Fruits are generally subjected to mechanical forces during harvesting, handling, and transportation that may cause damage in the form of bruises, punctures, and cracks. In order to prevent damage, and insure better quality fruits for consumers, it is very essential to study physical properties of these materials. The studies were conducted to examine the effect of storage period, storage condition, and other factors, such as loading rate and initial strain, on the stress relaxation behavior of the fruit flesh, and develop nonlinear viscoelastic models to represent its stress relaxation behavior. The following results were obtained from the study : 1. Since the viscoelastic behavior of the fruits flesh was nonlinear, the behavior was satisfactorily modelled as follows ; $${\delta}({\varepsilon},\;t)={\varepsilon}^A[B\;{\exp}(-Ct)+D\;{\exp}(-Ft)+G(-Ht)]$$ But, for the every strain applied, the stress relaxation behavior of the fruit flesh, such as apple and pear, could be well described by the Generalized Maxwell model, respectively. 2. The effect of loading rate on the stress relaxation behavior was remarkable. The higher loading rate resulted in the higher initial stress, and the faster stress relaxation. 3. The higher initial strain resulted in the higher initial stress, and stress relaxed at the large initial strain was also much higher than at the small initial strain. 4. Stress relaxation rate and quantity stored in the fruits at the low temperature storage were much higher than those at the normal temperature storage in the same storage period. Also, in all fruits tested, the longer storage period was the more relaxation rate and quantity were shown. These trends in the normal temperature condition was the more significant than in the low temperature condition.

• Child Health Nursing Research
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• v.5 no.1
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• pp.5-17
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• 1999

This study was designed to determine the schemata and their characteristics of stress experience the subjectivity of stress experience(structure of subjectivity) would be a basic step for the effective clinical education through the stress management for characteristics of these types. Q-methodological method was used for that purpose. The research method statements were collected prior to the study through indepth interviews. For the study, 31 Q-statements were selected. There were 34 nursing students as subjects for the research. The 34 nursing students sorted the 31 statements using the principal of forced normal distribution. The principle of forced normal distribution, which has 9 scales to measure the individual opinions, was called. Q-factor analysis by using PC QUANL program supply the material. According to the outcomes of this study, there were 3 types of special opinion about the stress experience of clinical practice. The first type is called 'Influence of practical atmosphere type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The second type is called 'conflict of nursing role type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The third type is called 'Lack of confidence type'. Members of this type experienced stress because of a lack of confidence for their own nursing knowledge and skill. As a result, we now need further study to identify individual psychological aspects of stress for clinical practice. The findings will guide the development in effective approaches for clinical education. Finally, the result of the study will provide us the need for developing systematic and integrated practice education program for students and active involvement of clinical instructor.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.1
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• pp.58-72
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• 2004

Statement of problem : Clinically, maxillary first premolar has a high risk of fracture. This is thought to be caused by the susceptible figure which the maxillary first premolar has In other words, sharp cusp angles of the premolar is thought to influence this situation. Purpose : This study was to know stress distribution of all-ceramic crown according to the cusp angle. Material and Method : It was manufactured a three dimensional finite element model simplified maxillary first premolar, and then analyzed stress distribution when cusp angle was each $80^{\circ}$, $90^{\circ}$, $100^{\circ}$, $110^{\circ}$ and $120^{\circ}$. Results and conclusion : 1. The von Misses stress showed that stress decreases as cusp angle increases in the central groove of the occlusal surface. 2. It showed that maximum principal stress was centered at the region of the central groove of the occlusal surface and a region which the force was inflicted. And also it appeared high on the lingual and buccal side of finish line. 3. The X axis of normal stress was focused in the central groove of the occlusal surface. The Y axis normal stress appeared high in the central groove of the occlusal surface, buccal and lingual side. 4. The Stress near the finish line showed a low value compared with stress in the region of the central groove of the occlusal surface. 5. It shows that the most dangerous angle for tooth fracture was on $80^{\circ}$ of the cusp angle and low on $120^{\circ}$ of its.

• Journal of Sasang Constitutional Medicine
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• v.18 no.3
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• pp.155-165
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• 2006

1. Objectives The purpose of this research is to find out the Constitutional difference of Oxidative stress by Free oxygen radicals. 2. Methods We enrolled 55 patients who visited our hospital for medical examination from February 1, 2006 to May 31, 2006. This research investigated the Constitutional difference of Oxidative stress by Free oxygen radicals. 3. Results and Conclusions l) The Sasang Constitutional distribution of patients have oxidatative stress by Free oxygen radicals was Taeunmin 30%(8persons of total 27persons), Soeumin 56%(9persons of total 16persons), Soyangin 33%(4persons of total 12persons). The rate of patients have oxidatate stress was high in Soeumin. The Sasang Constitution had significance relation with oxidatative stress by Free oxygen radicals. 2) Triglyceride on the average of Taeumin patients have oxidatative stress by Free oxygen radicals is ststistical significantly higher than Triglyceride on the average of controlled normal persons in Taeumin(p-value=0.010) and Soyangin(p-value=0.015). Blood uric acid level on the average of patients have oxidatate stress by Free oxygen radicals is ststistical significantly lower than Blood uric acid level on the average of controlled normal persons in Taeumin(p-value=0.004) and Soyangin(p-value=0.037). This research has shown that there is a statistical significance between the Triglyceride level, Blood uric acid level and oxidatate stress by Free oxygen radicals.