• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.6
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• pp.877-884
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• 2005

The importance and usefulness of a subjective evaluation of the sensorial properties of scoured silk fabrics is discussed. Silk fabric was treated at 12 different scouring rates and the scoured fabrics were used as specimens. Using paired comparisons, three trained subjects, evaluated seven subjective sensorial properties; softness, elasticity, drape, stiffness, crispness, and luster. A quad experimental design was adopted as an effective and reliable evaluation method. Results showed that some properties such as drape, luster were easily discriminated depending on the scouring rates whereas the smoothness was not easily discriminated. As the scouring rate increased, it was hard to discriminated the softness, drape, and stiffness, which indicates there is an optimum scouring rates to have a certain sensorial properties. It was suggested that these results should be applied to the manufacturing process.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.974-978
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• 1999

This study was concerned with the scouring effect of anionic surfactants, PAPE(sodium polyoxyethylene alkyl phosphoric ester) for cotton fibres. Sodium polyoxyethylene(7) nonylphenyl phosphoric ester(CPB-1) and the sodium polyoxyethylene(7) tridecyl phosphoric ester(CPB-2) were synthesized by the phosphoric esterification reaction from NP-7(polyoxyethylene(7) nonylphenyl ether) and TDA-7(polyoxyethylene(7) tridecyl ether) as scouring agents. Defoaming ability, fibre wetting time and absorbency rate of scouring agents were investigated. Being compared with the conventional scouring agent(Ultravon GP; Ciba-guyge Co.), CPB-1 and CPB-2 showed a higher defoaming ability in the cotton scouring process at room temperature. And CPB-1 has a higher wetting effect than the agents, CPB-2 or GP in distilled water bath but CPB-2 showed more scouring effect in 1.2 wt % NaOH solution bath.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.133-139
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• 2019

In this study, the degree of scouring according to the bed material according to the flow rate and the relationship between the flow velocity and the bed scouring were investigated in order to examine the operability of the revetment and embankment. The materials used in the experiment were sand and loess as materials used in the embankment. We measured the scouring of the material according to the change of the flow velocity by using the indoor high flow velocity experiment device and verified the flow rate. In this way, The purpose of this study was to compare and analyze changes in material before and after scouring, and compare basal scouring evaluation by bed material with high flow velocity. In case of sand, the cohesive force is very weak, so more than 40% of the material is lost even at less than 1.0 m/s. In the case of loess, less than 6% of the bed material is lost at more than 2 m/s. The reason why the material was lost was that the cohesion was so strong that the material was dried after the compaction and cracked. As a result, the material was lost from the part where the dry crack occurred. In this study, the composition and loss of bed materials were evaluated.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.71-80
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• 2005

More than 100 bridges have been annually collapsed or seriously damaged by scouring in Korea. It is extremely hard to understand the complicated scour mechanism and estimate the scour depth with accuracy in fields, however since scouring is a very complex manifestation of sediment transport unable to describe with a simple mathematical tool. In order to obtain the reasonable solution to bridge scouring, therefore, the interdisciplinary co-operation is strongly recommended. In this study the special task force team for the scour problems around Incheon 2nd bridge piers is made, in which all kinds of scour oriented researches such as oceangraphic survey, hydraulic model test, numerical simulation, scour rate test, real-time scour monitoring, etc will be carried out. This paper provides this interdisciplinary procedure in details.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.67-73
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• 1988

This study was conducted to isolate etiological agents from the 103 scouring piglets in Gyeongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical served. The incidence of scouring piglet was most prevalent as 81.6% in the age of 2 to 4 weeks after birth, while the rate was less than 10% in the age of 5 to 6 weeks and under 1 week after birch. When compared the isolation frequency of the each etiological agent, enteropathogenic E. coli was most prevalent as 46.6%, thermophilic Campylobacter 26.2% and Salmonellae was 8.7% in order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85 (20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni were belong to type I (50.0%) and II (25.0%), and most strains of C. coli were belong to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C. and each 1 strain was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, wherease about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C.jejuni and C. coli were sensitive to kanamycin and gentamicin.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.1 s.16
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• pp.45-53
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• 2005

Scour plays a principal role in maintaining stability and durability of bridges. Especially, in case of severe flood events, flow rate getting increase in a short time, scour can impede the functioning of bridges to the extent that they must be taken out of operation, and even can imperil their stability and structural integrity. In Korea, about 100 bridges were collapsed or damaged every you. Sufficient field investigation, however, was not made and, therefore, no adequate countermeasure for scouring is available. In this study, literature on scour-protection methods are reviewed and data on countermeasures of scouring which were collected through field investigation in central region of Korea are analyzed.

• Journal of the Korean Geosynthetics Society
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• v.16 no.1
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• pp.41-52
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• 2017

This research conducted the two types of model tests to examine the failure parameters by levee overflow, those were the pilot-scale levee (model height 0.4~0.8 m) and real scale levee (model height 1.0 m). The procedure of levee failure by overflow was succeeded to the following three steps: At first step, the local scouring on levee slope was happened and the overflow velocity was increased slowly. At second step, the enlarged scouring surface and the rapid overflow velocity were succeeded. At last, the levee section was broken totally and the overflow velocity was decreased because of the wide failure surface of levee. The levee failure angle (${\theta}$) was appeared bigger than slope failure angle of Rankine earth pressure. The enlarged levee height (H) made the faster overflow velocity (${\upsilon}$) of the levees, therefore additional tractive force was applied to it, futhermore the failure angle (${\theta}$) and failure surface (A) were enlarged. Because the sand sample for pilot-scale and real scale tests had the same diameter, the critical scouring velocity of each type was also the same, and the scouring properties were governed by variation of overflow velocity.

• Journal of the Korean Professional Engineers Association
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• v.15 no.2
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• pp.24-31
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• 1982

This study concerns with the reduction of the COD and deceleration of dyeing wastewater from DAEGU city area by ozonation. The COD reduction by ozonation follows near linear relationships versus ozonation time, temperature and concentration. The color in dyeing wastewater and of dyes can he strikingly reduced as the water is quasi colorless after ozone treatment. COD reduction rate of wastewater was found not to be dependented on pH, however, high temperature gave better results, although economically not feasible. The ozonation of dyeing wastewater can give good results when dyes, scouring agent and sticking agents were pre-separated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.821-834
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• 2015

This study presents the analysis of flow and bed change characteristics considering bed protection work built on the immediate downstream of weir to protect river bed from scouring. The study area is 37km reach from Hyunpoong station to Masuwon station including Hapcheon- Changryoung multi-function weir in the Nakdong river. CCHE2D model is calibrated and validated for evaluating the flow and bed change characteristics during Typhoon Kompasu in 2010. Three simulation conditions are set up: Case 1 is a natural channel without installation of weir. Case 2 involves an installation of weir in the natural channel. Case 3 involves an installation of weir with bed protection in the natural channel. Flood frequency (50, 100 and 200yr) is applied to each scenario to analyze the effects of bed protection work. While the sediment rate is increased in the downstream of fixed gate and sluice-type gate, river bed scouring rate is increased in the downstream of lift-type gate in Case 2 comparing with the results of Case 1. The river bed scouring is not occurred in the immediate downstream of weir (~30m) due to the effect of bed protection, but larger amount of sediment is occurred in the downstream of weir (60m~) which the bed protection is not installed comparing with the results Case 1. Through the results of simulation considering bed protection work, this study would be helpful to expect bed change and operate the weir as well as manage.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.838-845
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• 2006

Characterization of sediment in the riverbed is of importance for effective water quality management, yet have not been monitored sufficiently. This paper reports monitoring results of nutrient concentrations of sediments. Surface waters and sediments were sampled four times during rainy season at five monitoring points. Organics of overlying water were increased after high flow condition followed by decreasing tendencies. Soluble phosphorus fraction among total phosphorus was increased after high flow condition while total phosphorus was in decreasing tendencies. Monitoring result suggested that more extended monitoring scheme for flow rate, scouring velocity, and suspended material is required for analyzing relationship between water quality and sediment.