• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.1
• /
• pp.52-60
• /
• 2015

Nuclear power plant contain many dissimilar metal welds that connect carbon steel components with stainless steel pipes using alloy600 welding materials. Primary water stress corrosion cracks at dissimilar metal welds have been continuously reported around the world. In periodic integrity evaluations, dissimilar metal welds are examined using a generic ultrasonic testing procedure, KPD-UT-10. In this procedure, the gap between the probe and examination surface is limited to 1/32 inch (0.8mm). It is not easy to test some dissimilar metal welds in Korean plants applying ordinary technology because of their tapered shapes and irregular surface conditions. This paper introduces a method for applying a flexible phased array technology to improve the reliability of ultrasonic testing results for various shapes and surface conditions. The artificial flaws in specimens with irregular surfaces were completely detected using the flexible phased array ultrasonic technology. Therefore, it can be said that the technology is applicable to field examination.

• International Journal of Highway Engineering
• /
• v.3 no.1 s.7
• /
• pp.165-176
• /
• 2001

Joints in jointed concrete Pavement are designed to control against randomly occurred cracks within slabs, which may be caused by temperature or moisture variation. The advantage of these artificial cracks (joints) over naturally occurred cracks are easy access of protections, such as installation of joint seal and load transfer mechanism. The potential benefits of joint seals are to prevent infiltration of surface water through the joint into underlying soil and intrusion of incompressible materials (debris, fine size aggregate) in to the joint, which may prevent weakening of underlying soils and spallings due to excessive compressive stress, respectively. For the adequate design of joint seal, horizontal variation of joint widths (horizontal joint movements) are essential inputs. Based on long-term in-situ joint movement data of sixteen jointed concrete pavement sections in Long Term Performance Pavement Seasonal Monitoring Program (LTPP SMP), it was indicated that considerable Portion of joints showed no horizontal movements with change in temperature. This Phenomenon is called 'Joint Freezing'. Possible cause for joint freezing is that designed penetrated cracks do not occur at a joint. In this study, a model for the prediction of the ratio of freezing joints in a particular pavement sections is proposed. In addition, possible effects of joint freezing against pavement performance are addressed.

• Tunnel and Underground Space
• /
• v.18 no.6
• /
• pp.465-479
• /
• 2008

For the quantitative identification of rock behavior in shallow tunnels, we recommend using the rock behavior index (RBI) by the analytic hierarchy process (AHP) and the Rock Engineering Systems (RES). AHP and RES can aid engineers in effectively determining complex and un-structured rock behavior utilizing a structured pair-wise comparison matrix and an interaction matrix, respectively. Rock behavior types are categorized as rock fall, cave-in, and plastic deformation. Seven parameters influencing rock behavior for shallow depth rock tunnel are determined: uniaxial compressive strength, rock quality designation (RQD), joint surface condition, stress, pound water, earthquake, and tunnel span. They are classified into rock mass intrinsic, rock mass extrinsic, and design parameters. An advantage of this procedure is its ability to obtain each parameter's weight. We applied the proposed method to the basic design of Seoul Metro Line O and quantified the rock behavior into RBI on rock fall, cave-in, and plastic deformation. The study results demonstrate that AHP and RES can give engineers quantitative information on rock behavior.

• Biomolecules & Therapeutics
• /
• v.5 no.2
• /
• pp.165-173
• /
• 1997

This study was conducted to investigate the effect of DA-9601, an extract of Artemisiae Herba, which is known to possess mucoprotective action either by free radical scavenging effect or increase of mucus secretion, against animal models of inflammatory bowel disease (IBD) induced by trinirobenzene sulfonic acid (TNBS) or other noxious agents. Experimental colitis was induced by intracolonic administration of TNBS in 50% ethanol, or 1 ml of 7% acetic acid solution (AA), by subcutaneous injection of indomethacin (INDO) in rats, or by supplementing drinking water with 5% dextran sodium sulfate (DSS) in albino mice. DA-9601 was treated orally for 4 to 7 days. Animals were euthanized 1 day after the last treatment for morphological and biochemical analysises. All the noxious agents including TNBS, AA, INDO and DSS elicited severe colitis. The animals treated with DA-9601 showed a consistent, dose-related reduction in the severity of colitis, grossly and histologically. The reduction was significant (p<0.05) after administration of DA-9601 at dose range of 10 mg/kg or above. In TNBS-induced colitis, the rats receiving DA-9601 showed significantly decreased mucosal myeloperoxidase (MPO) and thiobarbituric acid-reactive substances (TBA-RS), when compared to control and mesalazine groups. Mucosal proinflammatory cytokine levels were also decreased after DA-9601 treatment. In conclusion, DA-9601 ameliorated macroscopic and histologic scores in experimental colitis either through decreasing oxidative stress or by attenuating cytokines involved in inflammation. DA-9601 could be a promising drug for the therapy of IBD.

• Journal of the Korean Society of School Health
• /
• v.33 no.2
• /
• pp.125-138
• /
• 2020

Purpose: The study investigated the effect of adolescent health behavior on the prevalence of current allergic diseases. Methods: The subjects were 57,303 middle and high school youth. Data were analyzed using Rao-Scott χ² test and complex sample logistic regression analysis. Results: While controlling the affect of the general characteristics of the subjects, health behaviors affecting the current prevalence of allergic diseases were smoking, drinking, physical activity, eating habits, drug abuse, and mental health. Smoking behaviors affecting the current prevalence of allergic diseases were lifetime smoking experience, smoking days, liquid e-cigarette lifetime smoking experience, number of liquid electronic cigarette smoking days, e-cigarette lifetime smoking experience, e-cigarette smoking days, amount of smoking, second-hand smoking and drinking behaviors were lifetime drinking, drinking days, the amount of drinking, and severe drinking. Variables such as physical activity exceeding 60 minutes days, intake of energy and sweet drinks, water intake, habitual drug use and mental health behavior such as stress perception, weekday sleep time, subjective sleep satisfaction, depression, suicidal thoughts/ plan/ attempts affect current allergic diseases (p<.001). Conclusion: The results showed that current allergic disease related health behaviors in Korean adolescents. Therefore, considering these factors, it may be helpful to facilitate a health promotion plan for prevention and management of such diseases and to promote evidence-based health practices at school.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.5
• /
• pp.332-339
• /
• 2014

This research was performed to test the hypothesis that the optimal fertilization rate for red pepper is changed by soil moisture condition. The experiment was conducted in rainfall-intercepted fields in Suwon, South Korea from 2002 to 2003. Soil was irrigated at 30, 50, or 80 kPa of soil moisture tension at 20 cm soil depth in 2002 and 30, 50, 100, or 150 kPa in 2003. For both years, fertilization was performed with four levels: none, 0.5, 1, and 1.5 times of the recommended N, P, and K fertilization rate. The irrigation amount was the greatest at 30 kPa irrigation while the water use efficiency increased with decrease of irrigation amount. The Irrigation amount was 508 mm at 30 kPa irrigation and ranged from 355 mm to 435 mm at 50 kPa irrigation. The maximum yield was found at 30 kPa irrigation and 1.5 times of the recommend fertilization rate in 2002 and 2003. The yield index of red pepper increased linearly with the fertilization rate at 30 kPa which implied that excess irrigation induced nutrient leaching and reduced nutrient availability. The maximum yield in 50 kPa and 80 kPa was found at the recommend fertilization rate while the yield decreased by fertilization at 100 kPa and 150 kPa irrigation. It implies that reduction of fertilization is the feasible practice to mitigate drought stress in fields without stable irrigation resources.

• Journal of Haehwa Medicine
• /
• v.18 no.2
• /
• pp.1-12
• /
• 2009

Most of the cholesterol is synthesized by liver in the body while about one of third is taken via dietary. The main functions of cholesterol is to protect membranes in cell surface, avoid the arterial bleeding by hypertension, and prolong the life of erythrocytes, and so on. However, overload of cholesterol leads to arteriosclerosis associated with leading death cause. Lack of physical activity, emotional and environmental stress, and low intake of protein or vitamin E induce the unbalance between HDL- and LDL-cholesterol so become a basis of ischemic disorders in heart, brain and elsewhere in the body. So far, four major classes of medications for hyperlipidemia are HMG-CoA reductase inhibitors (statins), bile acid sequestrants, nicotinic acid, and fibric acids. The statins can lower LDL and levels triglyceride, but may induce myopathy and an elevation of liver enzyme levels. The bile acid sequestrants lower LDL levels and raise HDL levels with no effect on triglyceride levels but side effects of gastrointestinal (GI) distress, constipation, and a decrease in the absorption of other drugs. Nicotinic acid and fibric acids lower LDL and triglyceride levels with showing flushing, hyperglycemia, hyperuricemia, GI distress, and hepatotoxicity dyspepsia, gallstones, myopathy, and unexplained noncardiac death as adverse effects. Above western drugs lower cholesterol by 15 to 30% while all have notable adverse effects. In traditional medicine, hyperlipidemia is regarded as retention of phlegm and fluid disease. Etiology and pathogenesis of hyperlipidemia is basically based on Spleen-Deficiency and Phlegm-Stagnation, accumulation and stasis of -heat, and Qi & blood stagnation induced by Phlegm-damp, water-dampness, and blood stasis. Thereby, strengthening Spleen and dissolving Phlegm, clearing away heat and diuresis, and supplementing Qi and activating blood circulation are commonly used therapeutic methods for hyperlipidemia. The traditional herbal medicine, have been used for patients with CVA, hypertension or hyperlipidemia in Oriental hospital or Oriental clinic. The lock and key theory is used to develop most of western medicine, however many diseases are caused by mixed factors in body-complex system. We expect that Oriental pharmacological theory could be newborn as a novel drug showing high advantage of blood levels of lipidsand QOL of performance without side effects.

• Journal of the Korea Furniture Society
• /
• v.22 no.1
• /
• pp.72-81
• /
• 2011

These days, beds have been developed not as furniture to sleep in but Healthcare Furniture. The function of heating, non-electronic-waves and far-infrared rays have been added. Also, eco-friendly materials such as stone, mud, rubber and wood are combined to them together with the radiation-heating method using heat conduction through electronic coil and hot water circulation. Modern people suffer from stress and fatigue. The hot issue is "health." Focused on the health, the development of design for beds considering the influence electronic waves, anions, deep sleep and the density of toxic materials have on human bodies has become urgent. In this study, the trend, specification and efficiency of the functional health-related electronic coil technology are analyzed. Through the analysis, the environmental standards are set. According to them, technology, eco-friendly materials and additional functions for the development of the design are considered. Also, the government is promoting the IEC international standardization for the Korean traditional floor heating style beds. In preparation for that, we adopted new HPT method technology. It enables non-electronic-waves, low electricity and stable temperature maintenance control for the warm top and the cool bottom. Also, the head boards and the frames of the beds can be separated. Through this separation, the beds can be easily moved or installed. Eco-friendly materials such as Hinoki cypress wood and red clay and the existing tables function are combined to the head boards so they can be used as drawers and display shelves. If they are used as separate items, they can be used as covers. This is how we suggest the design for the heating beds.

• Journal of Nutrition and Health
• /
• v.16 no.4
• /
• pp.243-252
• /
• 1983

This study was undertaken to invesigate the effect of early nutritional deprivation and environment on neurotransmitter concentrations and behavior in later life. The restoring process of rats fed foods ad libitum after 50% restriction of the casein or the Korean diet during the prenatal and/or the lactating periods was observed. There were two rearing conditions, isolated and enriched, after weaning. Behavioral development was measured by the Y- shaped water maze and the open field test. The neurotransmitters were analyzed after sacrifice at the age of 21 weeks. The results are summarized as follows. 1) The body weight impairment by dietary restriction during the prenatal and lactating periods could be restored within 18 weeks after weaning in case of living in a classical cage. The effect of quantitative restriction was bigger in the Korean diet than in the casein diet. 2) The brain weight was decreased by nutritional deprivation. Environmental enrichment increased it slightly. 3) The concentration of neurotransmitters, norepinephrine, dopamine, and serotonin, were not shown any traces of the dietary restriction at the age of 21 weeks. 4) In the maze test, the deprived rats made more errors than the nourished and the rats fed the Korean diet more than those fed the cascin dict. The environmental enrichment could decrease the number of errors. 5) In the open field test, the dietary deprived groups showed less reaction time, more squares entered in the field, and less number of fecal boli than the nourished among the environmentally isolated rats. However, rats living in the enriched cage without experience of nutritional stress showed the lowest emotionality and the elevated exploratory activity.

• Computational Structural Engineering
• /
• v.9 no.4
• /
• pp.189-198
• /
• 1996

The fracture behaviour of concrete gravity dam mainly due to uplift pressure acting at the crack face was studied. Triangular type and parabolic type distribution of the uplift pressure including uniform type were first considered in case of calculating stress intensity factor(SIF) by the surface integral method. Second, the directions of crack propagation according to the uplift pressure distribution were pursued by FRANC(FRacture ANalysis Code). Third, critical crack lengths according to the uplift pressure distribution under the overflow depth were calculated. The SIF values obtained from the surface integral method were compared with those by FRANC and relatively good agrements could be obtained between both of them. And it could be seen that the direction of crack propagation in case of triangular pressure distribution was a little benter to the dam base than the one by the uniform type. Maximum critical crack lengths under the overflow depth were obtained at about 2/5-1/2 of the dam height.