• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.212-219
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• 2007

This study were developed with the preventive structures of shore erosion using the seawater circulation system in wave dissipation block of the natural affinity. The shore protection structures were established to excellent by the hydraulic model experiment on reflectivity and stability and wave overtopping in comparison with existing other structures. These structures, in order to analyzes also as the shore protection and the erosion preventive, were examined with the field applications of performance and the capacity of prevention, respectively, from field construction of the pending positions. As the result, the structures were ensured with the applications and the efficiency as the shore protection structure of erosion preventive by certifying accumulated sediment deposits in the field measurement and monitoring.

• Water for future
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• v.35 no.5
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• pp.21-30
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• 2002

The inflow into a multi-purpose dam reservoir contains many suspended solids from the upper stream during the rainy season. Concentrations of SS increased to 73.3 mg/l and the TP measurement increased to 0.09 mg/l during the rainy season in 1999. It was discovered that particles less than $10\;\mu\textrm{m}$ in size composed about 50% of the total amount. Some of these particles reduce the reservoir capacity and have an impact on water. In this study, the sediment depth at Daecheong multi-purpose dam was examined. Piston coring was performed at 9 locations At Hoenam 1 out of 9 locations examined showed maximum depth, which was 90 cm and at Muneui 3 showed the minimum depth, which was 35 cm. At Hoenam, the release rate of TN was found to be $62.14~84.72\;mg/\textrm{m}^2{\cdot}day$ in 1998. However, it was found to considerably reduced to $23.20\;mg/\textrm{m}^2{\cdot}day$ in 2001. The release rate of TP was measured at $13.02~14.38\;mg/\textrm{m}^2$.day at 1998, and it was reduced to $6.93mg/\;mg/\textrm{m}^2{\cdot}day$ in 2001.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.40-47
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• 1993

Gelatinization properties of the air-dried sediment of cowpea were investigated. The water-binding capacity of cowpea flour was drastically increased over the temperature range of 52~55$^{\circ}C$. The percent transmittance of flour suspension was linearly increased at temperature between $65^{\circ}C$ to 75$^{\circ}C$. The gelatinization temperature determined by differential scanning calorimetry was 63.4~76.$0^{\circ}C$. Cowpea flour showed a single-stage of swelling and a low solubility pattern. The minimum moisture content required for the gelatinization was 37.0% . The amylograph peak viscosity was greatly influenced by concentration of the flour, but was not affected by heating temperatures (85~94$^{\circ}C$) at a given concentration. The 20 min height and cold viscosity at 3$0^{\circ}C$ at a fixed concentration was negatively correlated (p<0.05) with heating temperatures.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1315-1320
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• 2008

An experimental study was carried out to study the solid-liquid mixture upward flow in a vertical and inclined annulus with rotating inner cylinder. Lift forces acting on a fluidized particle plays a central role in many importance applications, such as the removal of drill cuttings in horizontal drill holes, sand transport in fractured reservoirs, sediment transport and cleaning of particles from surfaces, etc. Field measurements have revealed that the pressure drop over a borehole during drilling of a slim oil well or a well with a long reach can depend significantly on the rotation speed of the drill pipe. An accurate prediction of the annular frictional pressure drop is therefore important for conditions where the annular clearance is small. Effect of annulus inclination and drill pipe rotation on the carrying capacity of drilling fluid, particle rising velocity, and pressure drop in the slim hole annulus have been measured for fully developed flows of water and of aqueous solutions.

• Water for future
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• v.17 no.2
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• pp.107-112
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• 1984

It si presented here that in order to estimate reservoir sedimentation rate through the use of reservoir survey data of 66 irrigation reservoir in 3 major watersheds in this country, the correlation between reservoir sedimentation rate and the following factors; watershed area, trap-efficiency, watershed slope, shape factor of water shed, and reservoir deposition age in two models simple regression model and multiple regression model. Appropriatness of the proposed models have been calibrated from the survey data and as a result, it has been determined that the multiple regression model is much more accurate than the simple regression model. The annual sediment yield is correlated with watershed area and reservoir trap efficiency. It has been found that variation of the annual average sedimentation rate and the annual reservoir capacity loss rate are influenced by the trap efficiency of reservoir.

• Journal of Environmental Science International
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• v.12 no.11
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• pp.1173-1179
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• 2003

Laboratory sorption isotherm batch studies have been attempted to elucidate interaction of synthetic pyrethroids (bifenthrin and permethrin) with sediments and their fractions. As a nonlinear isothermal model, the Freundlich equation was applied to sorption results obtained from sediments to investigate the relationship between synthetic pyrethroids and sediments containing different amounts of organic carbon. Results demonstrated that the sorption capabilities of bifenthrin and cis- and trans-permethrin was in the order of bifenthrin, cis-permethrin and trans-permethrin, respectively, indicating that adsorbed bifenthrin was the most stable followed by cis- and trans-permethrin in all sediments. Their sorption capability was closely related to organic carbon contents in sediments. Higher sorption was observed in sediments containing higher organic carbon contents. Sorption study extended into the fractions, clay and humic acids, extracted from a sediment, indicated that higher sorption capacity in humic acids occurred than in the clay of both examined bifenthrin and permethrin. This study demonstrates the sorption of synthetic pyrethroids with sediments, and will help in the understanding of the transport and fate of synthetic pyrethroids existing in field sediments.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.907-912
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• 2008

In order to reduce the availability of dissolved inorganic phosphorus in surface water, lakes, and estuaries, black shale and zero valent iron can be used as reacitve materials. Sorption of phosphate to sampled sediment, black shale, and zero valent iron was quantitatively evaluated in this research. Effect of coexistence of calcium was also tested, since coexisting ions can enhance the precipitation of phosphate. An empirical kinetic model with fast sorption(k$_t$), slow sorption(k$_s$), and precipitation(k$_p$) was well fitted to experiment data from this research. Langmuir and Freundlich sorption isotherms were also used to evaluated phosphate maximum sorption capacity. Calcium ions at 0, 1 and 5 mM affected the precipitation kinetic coefficient in empirical kinetic model but did not have impact on the maximum sorbed concentration.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.53-62
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• 2009

This study was conducted to investigate characteristics of the non-point source pollution under construction and evaluate available pollution control methods. Suspended solid loading is high when soil disturbs by rainfall and this phenomenon is much more severe at the initial stage of construction than at the final one. There are three methods available for erosion and sediment control, which are check dam, silt fence, and geotextile. Check dam and silt fence are for control of suspense solids and geotextile is for preventing soil erosion during rainfall. They can be installed as temporary control facilities at construction sites. From the comparison of those methods, it was found that geotextile method was the most efficient for the runoff control of non-point source pollution. Check dam and silt fence can remove suspense solids by pore spaces to some degree, but the removal of pollutants mainly occurs through sedimentation. Because the temporary control facilities have limited removal efficiency of pollutant, they often cause civil claims and contamination of water environment. Hence, using a pressurized filtration system along with temporary control facilities, highly enhanced treatment efficiency was anticipated. In addition, the loading capacity of these techniques depends on filtration velocity and input loading. And their pre-treatments are necessary for efficient operation.

• Journal of Aquaculture
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• v.8 no.2
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• pp.85-98
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• 1995

In Kunsan coastal areas, there are some plans to construct industrial zone and, it will affect physical and chemical parameters of marine environment of the area. As one of many environmental surveys on the aquacultural farm in Korean west coast, the survey on the bottom sediment characteristics of intertidal farm was conducted from May 1992 to April 1993. Dominant grain size was fine sand $(69-98\%)$ and the pH of sediment was ranged of $7.2\~9.1$. Especially the pH increased after embank was constructed. The water holding capacity was $11.1-28.1\%$ and showed high value in silt and clay area. The COD was 1.27 mg/g dry mud and increased after embank was constructed. The total organic matter content ranged of $0.84-8.11\%$ and the DO absorption was $0\~6.56 mg/g$ dry mud. The value of DO absorption showed low in winter and spring, but high in summer and fall. The total nitrogen and the sulfide were rang of $0\~402{\mu}g/g$ dry mud and $0\~122{\mu}g/g$ dry mud respectively. These values were high in summer and winter season, and higher in upper layer than that of lower layer in general.

• Korean Journal of Remote Sensing
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• v.25 no.5
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• pp.445-454
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• 2009

Localized unprecedented torrential rain and heavy rainfall cause repeated damages and make it difficult to detect and predict the landslide caused by heavy rainfall. To analyze the landslide characteristics of Inje area this study used satellite images photographed after the occurrence of landslide caused by the typhoon Ewiniar occurred in July, 2006, and for GIS analysis purpose, interpreted the satellite images (SPOT5) visually to digitize into developing parts, water traveling parts and sediment parts. For analysis of spatial characteristics, landslide areas obtained from visual interpretation of digital map, 3rd & 4th forest vegetation maps and detailed soil map and grids were overlaid and analyzed. As a result, in regard to topographic features, landslide occurred at places, of which average slope is $26.34^{\circ}$, had south, south-east, south-west aspects and average altitude of 627m. From hydrological analysis, it was found out that water traveling area rapidly spread approaching water traveling area and sediment area. From forest type analysis, it was found out that landslide occurrence was high in pine woods, and in terms of girth class attribute, landslide occurred in small-sized woods, in which the crown occupancy of trees that have the diameter at breast height, 6~16cm, was greater than 50%. From the analysis of soil series, landslide areas constitute 37.85% of OdF and 37.35% of SmF, which had sandy loam soil and excellent drainage capacity. Through this study, landslides in Inje area were characterized and SPOT5 images of 2.5m resolution could be used. But there was a difficulty in determining water traveling parts adjacent to urban area.