• Proceedings of the KSME Conference
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• 2004.04a
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• pp.348-352
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• 2004

Recently the steel parts used for automiles and trains are required to be used under higher stress than ever before in need of the weight down. However, threr are a lot of problems with developing such of fatigue strength and fatigue life are mainly focused on by adopting residual stress. And got the following characteristics from crack growth test carried out stress ratio. Fatigue life shows more improvement in the Un-peening material. And Compressive residual stress of surface on the Shot-peening processed operate resistance force of fatigue. So we cam obtain fallowings. (1) The fatigue crack growth rate on stage II is conspicuous with the size of compressive residual stress and is dependent of Paris equation. (2) Although the maximum compressive residual stress is deeply and widely formed from surface, fatigue life does not improve than when maximum compressive residual stress is formed in surface. (3) The threshold stress intensity factor range is increased with increasing compressive residual stress.

• International Journal of Ocean System Engineering
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• v.2 no.2
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• pp.82-91
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• 2012

Fillet welding is widely used in the assembly of ships and offshore structures. The T-joint configuration is frequently reported to experience fatigue damage when a marine structure meets extreme loads such as storm loads. Fatigue damage is affected by the magnitude of residual stresses on the weld. Recently, many shipping registers and design guides have required that the fatigue strength assessment procedure of seagoing structures under wave-induced random loading and storm loading be compensated based on the effect of residual stresses. We propose a computational procedure to analyze the residual stresses in a T-joint. Residual stresses are measured by the X-ray diffraction (XRD) method, and a 3-D finite element analysis (FEA) is performed to obtain the residual stress profile in the T-joint. The proposed finite element model is validated by comparing experiments with computational results, and the characteristics of the residual stresses in the T-joint are discussed.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.6
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• pp.453-479
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• 2011

Residual pharmaceutical compounds have been recognized as emerging environmental pollutants and are widely distributed all over the world. These compounds cause bioaccumulation and biomagnification during present for a long time in the environment: thereby after adversely biota and human bodies. It is difficult to remove residual pharmaceutical compounds using conventional water/wastewater treatment because of resistant property to photodegradation, biodegradation and chemical decomposition. Moreover, domestic literature data on the pollution of residual pharmaceutical compounds in rivers and lakes are limited. In this paper, species, sources, fate and risk of residual pharmaceutical compounds as well as behavior properties in freshwater resources are demonstrated to encourage the domestic concern about residual pharmaceutical compounds. An extensive review of existing data in the form of figures and tables, encompassing many therapeutic classes are presented.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.177-182
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• 1983

In order to clarify the effect of the unilateral pneumonectomy on the compensatory growth of the residual lung, liver and kidney, and serum electrophoresis pattern, right lung pneumonectomy was performed on rabbits under general anesthesia with pentobarbital sodium. On the fifth day after the surgery, the weight of the residual lung, liver and bilateral kidneys was measured and organ weight-body weight ratio was calculated. And in an attempt to know whether the cells in the liver and the kidney were proliferated by unilateral pneumonectomy, DNA content was determined. The quantity(g/100 ml) of serum protein was determined also and serum electrophoresis was performed on cellulose acetate membrane. The results obtained are summarized as following. The weight of the residual lung and lung weight-body weight ratio was significantly increased respectively. The weight of the liver and organ weight-body weight ratio were not changed but the DNA content of the liver and kidney tissue increased significantly, illustrating that unilateral pneumonectomy caused cellular hyperplasia in the liver and in the kidney as well as in the residual lung. The quantity(g/100 ml) of serum protein was significantly increased and in the analysis of the electrophoregram, there was significant difference between the normal and pneumonectomy group. Taken together, these results indicate that unilateral pneumonectomy caused the compensatory hyperplasia of the liver, the kidney and the residual lung as well as the change of electro-phoretic pattern. And it also suggests that a humoral factor, which proliferates the cells in the residual lung, the liver and the kidney, existed in the pneumonectomized rabbits.

• Corrosion Science and Technology
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• v.17 no.1
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• pp.12-19
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• 2018

Langelier Index (LI) is used as a tap water corrosiveness index. Residual chlorine in tap water induces corrosion inside water pipes. This study takes a deeper look into the effect of residual chlorine in water pipes. Comparison between tap waters of Y and K water treatment plant (WTP) shows that the LI index of K WTP is lower than that of Y. However, the corrosion rate of Y WTP is higher than that of K WTP. This means that the higher the concentration of residual chlorine in tap water, the higher the corrosion rate of pipe materials. When calcium hydroxide was added to tap water, the corrosiveness index was improved and thus the corrosion rate reduced. It is possible to increase the disinfection efficiency by increasing the duration of residual chlorine and suppressing the rust generation of water pipes and to supply minerals. A guideline for corrosion control with residual chlorine should be set up. The effects of residual chlorine should be included in the corrosiveness index of tap water.

• Korean Journal of Community Nutrition
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• v.3 no.3
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• pp.454-465
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• 1998

This study was to investigate the recognition level of food contamination with residual pesticides and hazardous heavy metals from 365 male and female adults in Taejon area using questionnaires. Among the recognizing level of residual pesticides in overall foods, 69.1% were 'serious', 25.6% were 'average' and 5.3% were 'not serious'. Over 94.7% of the subjects recognized residual pesticides pollution infoods. for hazardous heavy metals in food, 47.8% responsed as 'serious', 40.5% as 'average' and 11.8 as ' not serious' . Over 88.3% of the subjects recognized contaminated pesticides seriously in fruits, 72.1% in vegetables and 51.7% in cereals, whereas 55.7% of the subjects recognized hazardous heavy metal contamination seriously in fruits, 53.4% in vegetables, 40.8% in fishes and shellfishes and 35.0% in seaweeds. The subjects recognized residual pesticides contamination more seriously in overall foods, cereal, potatoes and starches, bean, vegetables and fruits, whereas hazardous heavy metal contamination was recognized more seriously in fishes and shellfishes, and seaweeds food groups. Comparisons were shown based on individuial's occupation. Farmer, forester, iner and fisher showed the lowest recognizing level of food contamination in most food groups. The mean score of the dietary effect by mass media's information on food contamination from residual pesticides and hazardous heavy metals were 3.51±0.96 out of 5 points. By Duncan's multiple range test, sex, age, marriage, food cost per month, concerns about health and nutrition knowledge showed significant differences in the mean effect score at p<0.05. According to a pesticides contamination in several food groups were affected by food cost per month, mass media's information on food contamination, health status, and concerns about health, But a recognition level of hazardous heavy metals in food were affected by income and, food cost per month mass media's information on food contamination, health status, concern about health and nutrition knowledge. People who need to take extreme precautions of food contamination were in order of producers, government officials, homemakers, the consumer's association and consumers.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.608-619
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• 2017

In this paper, the effects of parameters related to the residual stress induced due to laser shock peening process to determine mitigation of the initial tensile residual stresses are discussed, such as the maximum pressure, pressure pulse duration, laser spot size and number of laser shots. In order to estimate the influence of the initial tensile residual stresses, which is generated by welding in 35CD4 50HRC steel alloy, the initial condition option was employed in the finite element code. It is found that $2{\times}HEL$ maximum pressure and a certain range of the pressure pulse duration time can produce maximum mitigation effects near the surface and depth, regardless of the magnitudes of tensile residual stess. But plastically affected depth increase with increasing maximum pressure and pressure pulse duration time. For the laser spot size, maximum compressive residual stresses have almost constant values. But LSP is more effective with increasing the magnitudes of tensile residual stress. For the multiple LSP, magnitudes of compressive residual stresses and plastically affected depths are found to increase with increasing number of laser shots, but the effect is less pronounced for more laser shots. And to conclude, even though the initial tensile residual stresses such as weld residual stress field are existed, LSP is enough to make the surface and depth reinforcement effects.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.83-88
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• 2001

Residual effect of imidacloprid on brown planthopper (BPH) and residues on rice plant were investigated in pot and field tests. Residual effect (showing 100% mortality) of imidacloprid of granule formulation on the BPH lasted for 40 days at a recommended dose (0.3 kg a.i./ha) and for 30 and 20 days at a half and a quarter of the recommended dose, respectively. In case of liquid formulation of imidacloprid, the residual effect lasted for 40 days at both recommended dose (0.032 kg a.i.1ha) and a half of it, and lasted for 30 days at a quarter of it. The next generation formation of BPH was throughly depressed by the imidacloprid application at the former generation. This result supports the residual effect of imidacloprid on BPH. Seed dressing (3 ghg) showed insecticidal activity (96.7% mortality) for 55 days after treatment. When granule formulation of imidacloprid was applied to soil at a recommended dose , imidacloprid residue in leaves of rice plant increased up to 0.46 ppd for 6 days and then decreased to 0.09 ppm on 40 days after application. Residue of imidacloprid in leaves of rice plant increased up to about 0.23 ppm and about 0.2 ppm for 6 days when applied at a half and a quarter of the recommended dose, respectively and after that they decreased.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.156-158
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• 2003

Sheets of aluminum alloy 1050 were asymmetrically cold rolled in a rolling mill with different roll speeds. In order to promote the shear deformation during asymmetrical rolling, cold rolling without lubrication was performed. The variation of the shear strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced residual shear strain gradients throughout the thickness layers.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.823-830
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• 2001

The single fiber pull-out technique has been commonly used to characterize the mechanical behavior of fiber/matrix interface in fiber reinforced composite materials. In this study, an improved analysis considering the effect of thermal residual stresses in both radial and axial directions is developed for the single fiber pull-out test. It is found to have the pronounced effects on the stress transfer properties across the interface and the interfacial debonding behavior.