• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.135-137
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• 1968

Bathythermograph (B. T) has been coumonly used to obtain a records of water temperature in the depth of 270m from the surface. We have, however, experienced some difficulties in obtaining smoked or coated glass which is used for the bathythermograph in this region, Therefore I introduce a easy method of preparing the smoked-glass slide. Preparing method is as follows. 1. Glass slides must be cleaned by dipping into the concentrated solution of sodium hydroxide ana hydrochloric acid then rinsing with hot water and polishing with a clean gauge. 2. The cleaned slide is immersed in the wax solution for coating, and dried on the filter paper. The Wax solution is prepared as follow : 1g of white wax is dissolved in 200CC of benzol or 1g of lard is dissolved in 300CC of gasoline. 3. A slide held in a fingertip is smoked on the flame of alcohol lamp, or Meter burner. When alcohol lamp is used the fuel alcohol must contain 1/5 of benzol, and when Meker burner is used, the air intake must be blocked up. The smoking on the glass slide should be light and uniform, after smoking the slide is cooled down. 4. The smoked glass slide is again dipped into the wax solution using a fingertip and the excessive wax solution on the slide is absorbed on the filter paper and drain off. 5. Thus prepared smoked slide can be used for B.T.

• Korean Journal of Microbiology
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• v.31 no.3
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• pp.255-260
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• 1993

The Enterobacter cloacae biofilms developed on slide glasses and galvanized-iron coupons were applied to test the attached bacterial resistance to chlorination. The chlorine resistances of biofilm bacteria grown on the slide glasses and galvanized-iron coupons were 14 and 480 times that of the suspended bacteria, respectively. The chlorine resistance of particleattached bacterial populations was 48 times that of suspended bacterial populations. The biofilm bacterial densities developed on the slide glasses and galvanized-iron coupons which were immersed in the flowing tap water for 75 days were $4.75 {\times} 10^{4}$ and $1.12 {\times} 10^5 cfu/cm^{2}$ It is concluded that main mechanisms of enteric or HPC bacterial resistance to chlorination in tap waters are bacterial attachment or . adsorption to particles or bacterial aggregations and formation of biofilms on the inner wall of distribution systems by escaped bacteria from chlorination in water treatment processes, which results in bacterial regrowth in water distribution systems.

• Smart Structures and Systems
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• v.24 no.6
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• pp.793-802
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• 2019

The centrifuge model test is usually used for two-dimensional deformation and instability study of the soil slopes. As a typical loose slope, the municipal solid waste (MSW) landfill is easy to slide with large deformation, under high water levels or large earthquakes. A series of centrifuge model tests of landfill slide induced by rising water level and earthquake were carried out. The particle image velocimetry (PIV), laser displacement transducer (LDT) and marker tracer (MT) methods were used to measure the deformation of the landfill under different centrifugal accelerations, water levels and earthquake magnitudes. The PIV method realized the observation of continuous deformation of the landfill model, and its results were consistent with those by LDT, which had higher precision than the MT method. The deformation of the landfill was mainly vertically downward and increased linearly with the rising centrifugal acceleration. When the water level rose, the horizontal deformation of the landfill developed gradually due to the seepage, and a global slide surface formed when the critical water level was reached. The seismic deformation of the landfill was mainly vertical at a low water level, but significant horizontal deformation occurred under a high water level. The results of the tests and analyses verified the applicability of PIV in the two-dimensional deformation measurement in the centrifuge model tests of the MSW landfill, and provide an important basis for revealing the instability mechanism of landfills under extreme hydraulic and seismic conditions.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.399-404
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• 2008

The influence of gas hydrate dissociation on submarine slope stability was studied in this paper. Gas hydrates are stable under high pressure and low temperature conditions. Once gas hydrate dissociates due to natural or human activities, it generates large amount of gas and water. During gas hydrate dissociation, a pore pressure between soil particles increases and results in the loss of an effective stress and degradation of soil stiffness. A pore pressures model was proposed to calculated excess pore pressures generated by gas hydrate dissociation at the Storegga Slide. A slope stability analysis for the Storegga Slide using a two dimensional finite difference method was carried out by considering excess pore pressures due to gas hydrate dissociation. Since the excess pore pressure calculated by the proposed method resulted in the considerable loss of stiffness and strength in slope, a submarine slope failure occurred at the Storegga slide was well simulated.

• Geomechanics and Engineering
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• v.8 no.3
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• pp.391-414
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• 2015

In this paper, stabilities of a plane slide rock slope under different hydraulic distributions were studied based on the nonlinear Barton-Bandis (B-B) failure criterion. The influence of various parameters on the stability of rock slopes was analyzed. Parametric analysis indicated that studying the factor of safety (FS) of planar slide rock slopes using the B-B failure criterion is both simple and effective and that the effects of the basic friction angle of the joint (${\varphi}_b$), the joint roughness coefficient (JRC), and the joint compressive strength (JCS) on the FS of a planar slide rock slope are significant. Qualitatively, the influence of the JCS on the FS of a slope is small, whereas the influences of the ${\varphi}_b$ and the JRC are significant. The FS of the rock slope decreases as the water in a tension crack becomes deeper. This trend is more significant when the flow outlet is blocked, a situation that is particularly prevalent in regions with permafrost or seasonal frozen soil. Finally, the work is extended to study the reliability of the slope against plane failure according to the uncertainty from physical and mechanics parameters.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.3
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• pp.42-49
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• 1993

Recently, because the lubricating oil showed a tendency to be emulsified and oxidized by high speed, high output and the extension of maintenance & conservation of marine engine, the cavitation erosion-corrosion at such an environment became a big problem on effective performance of engine. Therefore, there was a need to study the behavior and protection of erosion-corrosion damage, and then applied inhibitor to a protective method of cavitation erosion- corrosion damage. At this time, test environments were marine lubricating oil & various emulsified oil that mixed distilled water and sea water etc., and also used 20KHz, 24.mu.m piezoelectric vibrator as an experimental apparatus of cavitation erosion. With this apparatus, we investigated an influence of the emulsified oil on characteristics of erosion-corrosion and protection for erosion-corrosion by inhibitor at slide bearing metals.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.283-298
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• 2022

Landslides triggered by the combination of heavy precipitation and anthropological disturbance in hilly areas cause severe damage to human lives, properties, and infrastructure constructions. A comprehensive investigation of the influencing factors and failure mechanisms of landslides are significant for disaster mitigation and prevention. This paper utilized the combination of detailed geological investigation, physical experimental testing as well as numerical modelling to determine the failure mechanism, and proposed a countermeasures of the Lantian landslide occurred on 2, July 2017. The results reveal that the Lantian landslide is a catastrophic reactivated slide which occurred in an active tectonic region in Southwest China. Because of the unique geological settings, the fully to highly weathered basalts in the study area with well-developed fractures favored the rainwater infiltration, which is the beneficial to slide reactivation. Engineering excavation and heavy precipitation are the main triggering factors to activate the slide motion. Two failure stages have been identified in the landslide. The first phase involves a shallow mass collapse originated at the upper slopes, which extends from the road to platform at rear part, which is triggered by excavation in the landslide region. Subjected to the following prolonged rainfall from 19 June to 2 July, 2017, the pore water pressure of the slope continually increased, and the groundwater table successively rise, resulting in a significant decrease of soil strength which leads to successive large-scale deep slide. Thereinto, the shallow collapse played a significant role in the formation of the deep slide. Based on the formation mechanisms of the landslide, detailed engineering mitigation measures, involving slope cutting, anchor cable frame, shotcrete and anchorage, retaining wall and intercepting ditch were suggested to reduce the future failure risk of the landslide.

• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.119-129
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• 1986

Disappearence of the trichlorfon (Dipterex) in the forest, following aerial to control Agelastica coerulea B., were studied by sampling deposits on slide glasses, soils, water, and leaves, and analysing with a gas chromatograph equipped with an electron capture detector. By analysing the amount remained on slide glasses, it was shown that the pesticide was adequately sprayed and nearly all deposit was lost in a day. The amount deposited under the tree was about 1/100 of the amount at an exposed site. Concentration of trichlorfon in creek water was 10 to 100 times as high as the acute toxic level to zooplankton for 6 to 24 hours, The rain could recontaminate the stream water up to the toxic level. Loss rate of trichlorfon from soils showed variations by sampling sites and was generally slower than from slide glasses. Amount deposited on leaves were less than the calculated or expected amount. The loss from leaves were similar to that from soil.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.201-207
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• 2016

Purpose: A water-spraying type automatic glochids removal system for cactus (Opuntia humifusa) stem was developed, and its performance was evaluated. The system was developed to reduce intensive human labor in removing glochids from cactus stem skin without inducing damage prior to further processing into value-added products. Methods: The developed system consists of conveyor and water-spraying systems. The conveyor system delivers cactus stems through water-spraying compartments and finally to a collecting box. In order to remove the glochids, rotating nozzles spray water over all areas (i.e., front and back faces and sides) of the cactus skin under controlled water pressure. Operating conditions such as conveyor speed, water pressure, angle of water-spraying nozzles, distance between conveyor belt and rotating nozzles, and angle of cactus flipping slide were adopted from our previous study and applied on the system design and manufacturing. The performance of glochids removal was evaluated by counting the number of glochids on the cactus stem before and after processing on the system. Results: The developed system performed efficiently and effectively under the pre-studied operating conditions except for the angle of cactus flipping slide. The new system had a glochids removal ratio of 94.1% without damaging the cactus skin. Considering the original number (approximately 30-60) of glochids, the remaining number was low (1-4), and most of them were found at the side edge of the cactus stem. This system can remove glochids from 360 cactus stems in 1 hr regardless of cactus size. Conclusions: The performance of the new system in glochids removal without damaging cactus skin is superior to any other existing device (i.e., brush type, rubber-friction type, and agitation type). The system is expected to be applied in cactus (O. humifusa) processing facilities.

• Geomechanics and Engineering
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• v.8 no.4
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• pp.511-521
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• 2015

It is a common failure type that high-filled embankment slope sideslips. The deformation mechanism and factors influencing the sideslip of embankment slope is the key to reduce the probability of this kind of engineering disaster. Taking Liujiawan high-filled embankment slope as an example, the deformation and failure characteristics of embankment slope and sheet-pile wall are studied, and the factors influencing instability are analyzed, then the correlation of deformation rate of the anti-slide plies and each factor is calculated with multivariate linear regression analysis. The result shows that: (1) The length of anchoring segment is not long enough, and displacement direction of embankment and retaining structure are perpendicular to the trend of the highway; (2) The length of the cantilever segment is so large that the active earth pressures behind the piles are very large. Additionally, the surface drainage is not smooth, which leads to form a potential sliding zone between bottom of the backfill and the primary surface; (3) The thickness of the backfill and the length of the anti-slide pile cantilever segment have positive correlation with the deformation whereas the thickness of anti-slide pile through mudstone has a negative correlation with the deformation. On the other hand the surface water is a little disadvantage on the embankment stability.