• 한국산림과학회지
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• 제20권1호
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• pp.51-60
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• 1973

The trend and achievments of soil erosion control research in Japan were investigated through observation tours and reference work and following facts were found to be important aspects which should be considered in the soil erosion control research program in Korea. Experiments on forest and water relations, and ground water phenomena at the water source zone in Tokyo University. Studies on land-slides and erosion control dam in Kyoto University. Studies on mud-flow and snow avalanches in Hokkaido University. Studies on sanddune fixation and disaster damage prevention forests in Kyushu University. Studies on forest denudations in Nagoya University. Studies on Greening-works and soil erosion prevention chemicals in Tokyo Agriculture University. Training on planning of erosion control works and prevention of disaster damages in Forest Research Institute. Experiments on soil erosion phenomena and infiltration in Tohoku Branch, FRI. Experiments on erosion and surface stratum failure of steep slopes and their prevention methods in Railway Technical Research Institute.

• Corrosion Science and Technology
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• 제20권6호
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• pp.384-390
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• 2021

In this paper, durability evaluation and surface damage mechanism were investigated through solid particle erosion (SPE) test after applying hot-dip aluminizing (HDA) technology for the purpose of maintenance of marine economizer tube. Damaged surface shape was analyzed using SEM and 3D microscope. Compositional changes and microstructure of the HDA layer were analyzed through EDS and XRD. Durability was evaluated by analyzing weight loss and surface damage depth after SPE. HDA was confirmed to have a two-layer structure of Al and Al₅Fe₂. HDA+HT was made into a single alloy layer of Al₅Fe₂ by diffusion treatment. In the microstructure of HDA+HT, void and crack defect were induced during the crystal phase transformation process. The SPE damage mechanism depends on material properties. Plastic deformation occurred in the substrate and HDA due to ductility, whereas weight loss due to brittleness occurred significantly in HDA+HT. As a result, the substrate and HDA showed better SPE resistance than HDA+HT.

• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.13.1-13.7
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• 2018

Dental erosion is frequently overlooked in clinical practice. The management of erosion-induced damage to the dentition is often delayed, such that extensive occlusal rehabilitation is required. These cases can be diagnosed by a careful clinical examination and a thorough review of the patient's medical history and/or lifestyle habits. This case report presents the diagnosis, categorization, and management of a case of gastro-esophageal reflux disease-induced palatal erosion of the maxillary teeth. The early management of such cases is of utmost importance to delay or prevent the progression of damage both to the dentition and to occlusal stability. Non-invasive adhesively bonded restorations aid in achieving this goal.

• Tribology and Lubricants
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• 제9권1호
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• pp.55-61
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• 1993

Recently, due to the erosion damage that were generated increasingly at alloy metals of slide bearing by cavity of lubricating oil with tendency of high speed and high output of reciprocating engine, there is a need to study the process on the formation of cavitation erosion, and the characteristic of cavitation erosion at lubricating oil environments under various condition for marine ship. Therefore, the apparatus of cavitation erosion experiment used 20 KHz, $24 \mu m$ piezoelectric vibrator. The main results obtained through this test method are as follows: 1. The max. erosion rate at lubricating oil environments was related to the change of space, oil film thickness, and shown to tendency of gear oil>system oil>turbine oil>mixed oil environments with different viscosity. 2. The pitted hole by cavitation erosion at high viscosity oil environments became small and deep, and in addition to, they appeared to be wide and shallow at low viscosity.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.67-74
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• 1998

Two kinds of polished and unpolished freestanding films prepared by DC plasma CVD method were impacted by SiC particles to understand erosion mechanism. Erosion damage caused by solid impact was characterized by surface profilometer, scanning electron microscopy and Raman spectroscopy. Gradually decrease of surface roughness and sharp reduction of crystallinity for unpolished CVD films were observed with increasing erosion time. It was found that smaller grains of the diamond were removed in early stage of erosion process and larger grains were eroded with further impingement. By introduction of re-growth method on polished diamond, further understanding of erosion mechanism was achieved. Most of the surface fractures were initiated at the grain boundary.

• Journal of Forest and Environmental Science
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• 제26권3호
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• pp.181-192
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• 2010

Water erosion is progressing in the Loess Plateau, especially in gullies, and the sediment runoff to the Yellow River amounts to 975 million tons every year. Natural factors for water erosion include climate, soil, geological feature, terrain and vegetation. Many development projects due to the increasing population reduced the forest coverage ratio to 10%, and 200 million people in the downstream area are suffering from the damage during intense rainfall. Accordingly, the Chinese government is continuously trying to efficiently prevent the erosion by establishing measures for water erosion, including fish-scale pits, terrace technique, and check dams.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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• pp.359-365
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• 2000

Port facilities and marine structures used in marine environment were encountered to corrosion damages because of the influence of $Cl^-$. Generally, to protect these accidents, mainly applied anti-corrosion paint and epoxy coating. But it was still remained erosion-corrosion damage such as impingement erosion, cavitation erosion, deposit attack. There was needs to develope the new coating materials to protective those corrosion damages. This paper, polyester glass flake, vinylester glass flake lining and epoxy coating for SS were investigated electrochemical tests and cavitation erosion test for corrosion behaviour under sea water. The main results obtained are as follows, 1) Surface of epoxy coating appear erosion pin hole but surface of polyester glass flake and vinylester glass flake lining do not appear erosion pin hole after impingement-cavitation erosion test in sea water. 2) Weight loss of polyester glass flake and vinylester glass flake lining do not occur after impingement-cavitation erosion test in sea water. 3) Corrosion current density of polyester glass flake lining less drained than epoxy coating and substrate under corrosion potential.. 4) Corrosion current density of vinylester glass flake lining with three coating less drained than that of polyester glass flake lining with two coating.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.98-104
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• 2001

Recently, the researches on the prevention of marine oil pollution being strengthened. Sludge oils were unavoidably produced in ship's operations, therefore it is necessary to manage the sludge oils inside the ship itself with the view to prevent marine oil pollution from ship. The present study deals with the ultrasonic breaking systems that recycle the sludge oil from ships into usable oil to be burnt. At the first instanceexperimental studies were carried out to investigate the homogenizing effect of the marine oils and the erosion aspect of horn disc by repeated vibration of ultrasonic transducer. The erosion damages for horn disc SS41 steel with weight loss rate and the irradiation time to max. erosion rate were examined according to the variation of the transducer amplitude, the oil temperature and the immersing depth of horn disc. As the result of it, the erosion aspects of horn disk were varied with oil environments and testing time.

• 한국전기전자재료학회논문지
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• 제13권2호
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• pp.163-169
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• 2000

In this paper, we showed the erosion characteristic of MgO protector layer releated to lifetime of plasma display panel(PDP). We observed MgO erosion characteristic as a functions of deposition conditions, pressure and distance between electrodes. In RIE condition of Xe gas, the lowest erosion rate appears in the conditions of no heating bias voltage -30V and pressure 5mtorr. In general, as deposition rate increases, erosion rate decreases. In real panel, when the gap distance between electrodes is narrow and the pressure is low, the heavy plasma damage appears. Also, the surfaces between electrodes and on the bus electrode are extremely damaged.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.16-16
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• 2011

Plasmas in saline solutions receive considerable attention in recent years. How the operating parameters influence the plasma characteristics and how the electrode erosion occurs have been topics that require further study. In the first part of this talk, the effect of the frequency on the plasmas characteristics in saline solution driven by 50~1000 Hz AC power will be presented. Two distinct modes, namely bubble and jetting modes, are identified. The bubble mode occurs under low frequencies. In this mode, one mm-sized bubble is tightly attached to the electrode tip and oscillates with the applied voltage. With an increase in the frequency, it shows the jetting mode, in which many smaller bubbles are continuous formed and jetted away from the electrode surface. Multiple mechanisms that are potentially responsible to such a change in bubble dynamics have been proposed and the dominant mechanism is identified. From the Stark broadening of the hydrogen optical emission line, electron densities in both modes are estimated. It shows clearly that the driving frequency greatly influences the bubble dynamics, which in turn alters the plasma behavior. In the second part, the study of the erosion of a tungsten electrode immersed in saline solution under conditions suitable for bio-medical applications is presented. The electrode is immersed in 0.1 M saline solution and is positively or negatively biased using a DC power source up to 600 V. It is identified that when the electrode is positively biased, erosion by the surface electrolytic oxidation is the dominant mechanism with an applied voltage below 150 V. An increase in the applied voltage leads to the formation of the plasma and the damage by the plasma and the thermal effect becomes more prominent. The formation of the gas film at the electrode surface leads to the formation of the plasma and hinders the electrolytic erosion. In the negatively-biased electrode, no electrolytic oxidation is seen and the damage is mostly likely due to the plasma erosion and the thermal effect.