• Journal of Electrochemical Science and Technology
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• 제10권3호
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• pp.271-275
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• 2019

Anodic $TiO_2$ nanotubes were simultaneously grown and doped with $RuO_2$ by single-step anodization in a negatively-charged $RuO_4{^-}$ precursor. Subsequently, a high positive voltage was imposed on the nanotubes in an $F^-$-based electrolyte (a process referred to as potential shock), which led to the formation of a through-hole $RuO_2$-doped $TiO_2$ nanotube membrane without significant loss of the $RuO_2$ catalyst. XPS results confirmed that the doped Ru metal was converted into $RuO_2$ as the potential shock voltage increased. Further increases in the potential shock voltage led to the formation of $RuO_x/Ru$ in the $TiO_2$ nanotubes. All of our results clearly showed that a through-hole catalyst-doped $TiO_2$ nanotube membrane can be produced by a sequence consisting of single-step anodization and the potential shock process.

• 한국안전학회지
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• 제22권1호
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• pp.40-46
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• 2007

It is evaluated that electric shock risk in bath so that we made and designed a bathtub which is the same size in real public bath. And then, we did an experiment, provided of electric leakage in various conditions, so we measured how to form an electric potential and knew the electric potential is formed variously under exposed conductor in bath. Also, we made certain that electric shock risk is down if we insert an insulated pipe in bathtub pipe which is prevent from being formed the electric field sharply. The results show that the increased shock risk and safe distance are estimated by the bathtub of limited width and depth, and the voltage simulated on the basis of Flux 3D concept is compared with the measured value.

• 한국환경성돌연변이발암원학회지
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• 제25권1호
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• pp.32-39
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• 2005

In order to identify potential biomarkers of environmental monitoring, we evaluated heat shock genes expressions as effects of various environmental pollutants (nonylphenol, bisphenol-A, 17a­ethynyl estradiol, bis(2-ethylhexyl)phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride) on larvae of aquatic midge Chironomus tentans (Diptera, Chironomidae). Heat shock protein 70 gene expression increased in most of chemicals treated larvae compared to control. The response was rapid and sensitive to low chemical concentrations but not stressor specific. In conjunction with stressor specific biomarkers, heat shock protein 70 gene expression in Chironomus might be developed for assessing exposure to environmental stressors in the fresh water ecosystem. Considering the potential of Chironomus larvae as biomonitoring species, heat shock gene expression has a considerable potential as a sensitive biomarker for environmental monitoring in Chironomus.

• 한국안전학회지
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• 제22권2호
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• pp.41-46
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• 2007

This paper considers the electrical shock risk of the human body due to underwater leakage current in such places of public baths. Many submerged electric facilities in a public bath may create a severe electric shock hazard for the human body, since wet body in an accidentally energized bathtub can result in low electrical resistance through the human body for leakage or fault currents. Therefore a major consideration, in the context of electrical safety underwater, is the shock risk to the bather as a result of electric current flowing through the water in bathtub. To assess the electric shock risk and to analyze the potential distribution in a bathtub, 2 different situation cases are set up, then experimental and simulation methods are adopted. The validity of 2 cases of simulation and experiment data in a bathtub for electric distribution underwater are compared and analyzed. Also electric shock risk assessment underwater in a real public bathtub by simulation program package, Flux 3D, was conducted herein, and the results are presented and discussed.

• 한국안전학회지
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• 제23권6호
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• pp.44-50
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• 2008

This paper presents study on the electric potential distribution when have a short in street lamp. In order to measure electric potential testing ground is built in. A experiment is conducted to simulate dry and submerged situation of street lamp. The street lamp is leaked by artificial means. And electric potential is measured in grounded street lamp and street lamp alone. The results show that touch voltage of grounded street lamp is possible more high than street lamp alone. And the electric shock hazard is high because high electric potential is distributed near submerged street lamp. Also if street lamp is submerged ground is not useful to decrease electric shock hazard.

• 한국방재학회 논문집
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• 제7권5호
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• pp.111-118
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• 2007

최근에 들어와 가로등에 의한 감전사고가 지속적으로 발생하고 있다. 특히 집중호우로 인해 가로등이 침수될 경우 누전에 의한 감전 사고는 매우 높다. 전기감전사고가 발생할 경우 사고전압을 분석해 보면 주로 220V의 저압시설물에서 발생되고 있으나 이에 대한 위험성을 충분히 인식하지 못하고 있는 실정이다. 가로등 시설물의 사용전압 220V는 주로 일반인이 쉽게 접촉할 수 있는 도로변에 시설되어 있기 때문에 감전사고의 위험성은 매우 높은 편이다. 그러나 가로등 침수로 인해 누전이 발생했을 경우 누전체에서의 거리변화에 따른 수중전위분포가 인체에 미치는 영향을 연구하는 사례는 미약한 실정이다. 본 논문에서는 수중에서 누전이 발생했을 경우에 인체에 미치는 영향과 수중전위분포를 분석하고 수중에서 누전체와의 거리 및 깊이에 따른 변화가 어떻게 인체에 영향을 주는지 실험을 통하여 감전경로와 감전메카니즘을 비교 분석하고자 한다.

• 대한수학회논문집
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• 제15권1호
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• pp.155-172
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• 2000

Mode interactions at Unstable fluid interfaces induced by a shock wave (Richtmyer-Meshkov Instability) are studied both analytically and numerically. The analytical approach is based on a potential flow model with source singularities in incompressible fluids of infinite density ratio. The potential flow model shows that a single bubble has a decaying growth rates at late time and an asymptotic constant radius. Bubble interactions, bubbles of different radii propagates with different velocities and the leading bubbles grow in size at the expense of their neighboring bubbles, are predicted by the potential flow model. This phenomenon is validated by full numerical simulations of the Richtmyer-Meshkov instability in compressible fluids for initial multi-frequency perturbations on the unstable interface.

• 한국안전학회지
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• 제17권3호
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• pp.61-65
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• 2002

A study on the characteristics of electric shock in fresh water due to the leakage of submerged electric facility is conducted by using a reduced scale model at a scale of 1:10 in laboratory. Electric potential as a function of distance from leakage source, type of the leakage source, magnitude of the source voltage, submerged depth and diameter of a copper rod electrode is measured. On the basis of safety standard, separation for guarantee of safety is determined by the measured potential. Also supposing that body resistance is 500［$\Omega$］, the human reaction was estimated by calculating body current for some shock duration. Thus, in this paper, the hazard of the electric shock is assessed by introducing representative safety factors, body voltage and body current due to leakage source.

• 전기학회논문지P
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• 제56권4호
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• pp.195-200
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• 2007

This paper describes the countermeasures for preventing the electric shock which can be occurred in the low-voltage handhole underwater. Low-voltage handholes were designed and made for the test in the testing field. Which were installed 4 cases. a metal handhole cover was employed in case 1; FRP(Fiber glass Reinforced Plastic) handhole cover in case 2; an insulated rubber was put on the joint of the cables in case 3; the exposed conductors(cover, frame etc) were commoned and grounded in case 4. Thus, an ground potential near the low-voltage handhole was measured and evaluated quantitatively for the 4 cases. The measured results show that the potential of case 2.3 were lower than that of case 1 because the insulated rubber and the FRP cover prevented direct contact to the fault point. The case 4 is the lowest among the 4 cases because the common and grounding helps the fault current release into the ground, which makes the ground potential rise lower. As a result, although each case has the defects, these ways can effectively lower the electric shock risk in the low-voltage handhole.

• The Korean Journal of Physiology
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• 제2권1호
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• pp.47-52
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• 1968

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.