• Journal of Environmental Impact Assessment
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• v.17 no.6
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• pp.349-356
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• 2008

This paper aims to understand the effects of a turbidity flow intrusion on eutrophication in Daecheong Dam Reservoir. CE-QUAL-W2, a two-dimensional hydrodynamic and water quality model, is applied. The elevation of the reservoir water surface is used to validate the hydrodynamic model parameters and maximum fluctuations in the water surface elevations reaches about 1 m in the reservoir. During the heavy storm season, July, the thermocline submerged to less than 30 m below the surface. The thickness of the thermocline also reduced to 10 to 15 m. While the average TSS in June, the beginning of the monsoon was still low but it peaked in July due to heavy rainfall. Vertical profiles of the TSS regime in July indicated higher concentration in upper water layers and then the regime moves gradually downward in accordance with the time lapse. Due to the dam spillway opening, high concentrations of TSS attributed to storm turbidity ascended to the upper water layer by following the upward current movement and then, the regime precipitated to a layer below 30 to 40 m after September.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.169-173
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• 2008

A field monitoring was conducted in order to find out the discharge characteristics of non-point source pollutants in the agricultural area. Event Mean Concentration (EMC) of TSS, $BOD_5$, $COD_{Mn}$, TP, TN was calculated based on the monitoring data of 10 rainfall events at agricultural watersheds. A significant relationship was observed from the correlation between EMCs and rainfall characteristics. The result shows that EMC ranges of 95% confidence intervals were 50.5~203 mg/L for TSS, 0.8~14.2 mg/L for $BOD_5$, 4.2~20.7 mg/L for $COD_{Mn}$, 2.4~4.5 mg/L for TN and 0.2~0.5 mg/L for TP, respectively. The correlation coefficients between TSS and TP and between $BOD_5$ and $COD_{Mn}$ were found to be 0.912 and 0.961. But TN was lower correlated with other EMC factors. It was also found that rainfall characteristics was not correlated with EMCs.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.121-128
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• 2012

The purpose of this study is to solve the problem of nutrient removal due to rapid hydraulic retention time (HRT) variation in small size private sewage treatment facility and to have better effluent quality by using natural zeolite as a coagulant aid. The experiments were conducted by applying different conditions of HRT, coagulant, and zeolite dosages. As an experimental result, $TBOD_{5}$, TSS, and TP removal efficiencies were 64.9%, 94.5%, and 98.8% at co-injection with zeolite. Overall removal efficiencies of $TBOD_{5}$, TSS, and TP have improved 15.7, 28.7, 6.1%, respectively. This result shows that zeolite addition could improve flocculation, increase setting velocity, and thus have better treatment. Therefore the use of zeolite as a coagulant aid can be useful in small size private sewage treatment facility, where especially extra nutrient removal is required to meet the legal standard for discharge.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.93-103
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• 2008

This study was conducted to optimize a unidirectional flushing program in distribution pipes by analysis of water pressure, velocity, quality, and other parameters during flushing. As a result, correlation coefficient between flushed pipe length and the flushing duration was obtained $R^2=0.83$ and the equation $Y_{Time}=0.0571{\cdot}X_{Pipe\;length}+4.7648$ for 10 pipes. The averaged flushing velocity in the pipes, 1.1 m/s, was enough to remove loose deposits on the inner wall of the pipes. 3 of 92 water samples taken during flushing met the National Drinking Water Quality Standard for Fe and Mn, but not for Al. Turbidity less than 1 NTU is suggested for the appropriate criteria to finish flushing in pipes. The coefficient of determination ($R^2$) between turbidity and TSS was 0.95 and the equation was induced as $Y_{TSS}=1.2068{\cdot}X_{Turbidity}$. The amount of removed deposits could be estimated from the turbidity data of discharged water in field because turbidity and TSS in the discharged water is highly correlated.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.851-860
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• 2012

In this study, to evaluate the abatement of runoff pollution loads by the road sweeping(cleaning), various investigations are implemented at the sample area of the highway. As the results of evaluating the removal efficiency of pollutants along road cleaning, TSS showed about 78 % of the removal efficiency and COD showed 49 % of removal efficiency through the operation of cleaning vehicle of vacuum suction method. In case of TN and TP, they showed the relatively-lower removal efficiency by 30~35 %. TSS removal efficiency along the number of cleaning appeared about 60 % in case of one time of cleaning and the additional removal effect did not appear though the number of cleaning increased to two times. With running speed of cleaning vehicle, TSS removal ratio is lessened from 60 % to 20 % when cleaning vehicle speed up to 20 km/hr from 6 km/hr. It seems that the reasons why the removal efficiencies are inversely proportional to its speed are related to the lower vacuum efficiencies and the disturbed particles on the road. In the pollutant build-up analysis, it is showed that it takes more time to the critical pollutant build-up in the shoulder than the center of the road. It is also showed that the proper cleaning cycle is recommended as 4~6 dry weather days without rainfall events.

• Journal of Korean Society for Quality Management
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• v.32 no.4
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• pp.92-102
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• 2004

In this era of intense competition, TQM has become the key program in organizations as they strive for a competitive advantage. It has been applied to manufacturing and service sector since BNQA model was established in 1987. TQM literature for manufacturing sector abounds with empirical studies on the critical dimensions of TQM, but there is few empirical studies on the TQM evaluation for service sector. In this paper, two methodologies are applied to evaluate the TQM activities of service companies comparatively One of them is the traditional scoring system(TSS) by analytic hierarchy process(AHP). The other is the efficiency measuring system(EMS) by data envelopment analysis(DEA). DEA outperformed other alternative methods to measure the efficiency and it can be applied to evaluate the TQM activities. The objective of this paper is to evaluate TQM activities of domestic service companies by applying TAE(Total quality management Activities Evaluation) model to them. The result of this study is that TSS scores are not significantly correlated with EMS scores. It means that service organizations must not only make efforts to get the higher scores in terms of TSS but also take necessary steps to enhance their efficiencies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.85-90
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• 2004

The effect of the hydraulic residence time (HRT) for the removal of aquarium waste, such as protein, total suspended solids (TSS) and turbidity were investigated by using a foam separator Protein, TSS and turbidity removal efficiencies were increased with the increase of hydraulic residence time. The optimum hydraulic residence time was 0.5 min, and the highest protein and TSS removal rates were $14.4\;g/L{\cdot}day\;and\;38.9\;g/L{\cdot}day,$ respectively. The tendency of turbidity removal rate and efficiency was similar to that of protein.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.763-770
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• 2006

The purpose of this study was to investigate the effects of mechanical(ball-mill) solubilization of excess sludge especially focused on the TSS(total suspended solid) reduction during the conventional aerobic digestion of sewage sludges including primary and/or excess sludge, HRT was examined at the 10 days and 20 days. According to the results of this study, TSS removal efficiency of solubilized excess sludge was almost two times higher than that of non-solubilized excess sludge. And as the proportion of the primary sludge increased, TSS removal efficiency became worse because primary sludge rarely contained microbial cells which could be easily solubilized physically. It was also proved that by the application of proper solubilization techniques to the excess sludge, HRT for the aerobic digestion could be lessened(above 50%) dramatically keeping the same or better digestion performance. The fact that between primary and excess sludges, only the excess sludge is quite effective in the sludge solubilization and in it's reduction says that excess sludge releasing sources are key-point in the sludge cake reduction field as a source control.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.35-43
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• 2004

It is well known that the five-axis machining has advantages of tool accessibility and machined surface quality when compared with conventional three-axis machining. Traditional researches on the five-axis tool-path generation have addressed interferences such as cutter gouging, collision, machine kinematics and optimization of a CL(cutter location) or a cutter position. In the paper it is presented that optimal CL data for a face-milling cutter moving on a tool-path are obtained by incorporating TSS(tool swept surface) model. The TSS model from current CL position to the next CL position is constructed based on machine kinematics as well as cutter geometry, with which the deviation from the design surface can be computed. Then the next CC(cutter-contact) point should be adjusted such that the deviation conforms to given machining tolerance value. The proposed algorithm was implemented and applied to a marine propeller machining, which proved effective from a quantitative point of view. In addition, the algorithm using the TSS can also be applied to avoid cutter convex interferences in general three-axis NC machining.

• Elastomers and Composites
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• v.44 no.3
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• pp.260-268
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• 2009

Modification of clay surface was attempted by treating the clay with bis[(3-triethoxysilylpropyl)tetra sulfide (TSS) to raise the hydrophobicity and to induce a chemical reaction between the clay and the high temperature vulcanization-type silicone rubber matrix with purpose of improving the compatibility between the components, and thereby Na-$MMTS_4$ and Fe-$MMTS_4$ were synthesized by treating Na-MMT and Fe-MMT with TSS, respectively. Silicone rubber/clay composites were prepared by compounding the clays with silicone rubber. Thermal stability and mechanical properties were evaluated as a function of the clay types and the surface modification.