• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.6
• /
• pp.689-696
• /
• 2008

In a water treatment process a complete and homogeneous dispersion of the coagulants in the raw water could be most important factor. This research was performed to evaluate coagulation performance of the in-line-orifice mixer which was recently introduced as a rapid mixing device. The test was to determine the actual coagulant dispersion distribution on the overall cross-section at a distance of 1.6~3D from the chemical injection point by measuring zeta potential. From the results of zeta potential test, it was shown that the coagulant dispersion within the in-line orifice mixer was occurred very unevenly. The results have confirmed that it is necessary to increase the velocity of coagulants injection or pressurized water rates, in order to reduce nonuniform distribution of chemicals.

• Journal of the Korean Society of Safety
• /
• v.11 no.2
• /
• pp.109-115
• /
• 1996

The movement of water through a river embankment and its influenced upon the stability of the slope of the embankment are described. The stability of the embankment is depended upon the location of seepage line. As the seepage flow occurs in the embankment, the slope of the embankment loses its stability. Of particular interest is the stability following a rapid change of water level. The variation of seepage line in the embankment model by a fluctuation of water level is discussed. The experimental models were construction with slopes of 1 : 1.5, 1 : 2.0, 1 : 2.5 and the flow velocity was turned from 60cm/sec~90cm/sec. Based on the experimental study, the following conclusions are drawn. 1) When water level is raised, the seepage line of downstream slope Is raised rapidly as flow velocity increases. 2) For the case of permeable layer, the seepage line raised rapidly as compare with impermeable layer when water lever is raised.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.22 no.2
• /
• pp.64-82
• /
• 1980

The aim of this thesis, when water permeates dam, is to study the shape of seepage line and seepage quantity. As for the process, various sand model dams of same capacity were constructed in the water tank : they are a central, middle, inclined, up and down stream point of which is paralled, and filter-installed types. And the slope of seepage line and seepage quantity in these various models for experiment were measured, observed data were analyzed, and several formulas which already published were compared and examined. As for the shape of seepage line, the relation between upstream water level and exit: slope of seepage line, near the entrance and exit point, geometrically similar model, and the shape of seepage line filter-installed were examined. As regards to the seepage quantity, several formulas which already published and testing result values were compared and examined, and relation with the slope of seepage line, the seepage quantity, the slope of upstream point, and the upstream water level were mutually studied. Particulary, when horizontal filter was installed, propriety of the existing formulas for effective filter length w as examined, and the relative position of exit point in various. conditions was also studied.

• Water for future
• /
• v.14 no.2
• /
• pp.53-62
• /
• 1981

In the Hydraulic Structure, Such as dam body or levee of river that is constructed with soil, We analyzed a top line of free ground water table. This study is based on the logical reason that the pressure on the free surface is atmospheric and the seepage line is a stream line. In order to research for the unknown seepage line. We analyzed seepage water of steady flow through parous media by Finite Element method based on Galerkin Principle, and compared the comluted value with experimental value. The results show that the computed value was nearly equal to the experimental value. Finally, it noticed that finite Element method was more practical than Experimental Method for Seepage line analysis.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.171-178
• /
• 2006

In advanced countries, state-of-the-art temperature monitoring technique is widely used for effective use of geothermal resources. But these kind of modern tools such as Thermal Line Sensor has not been applied to find geothermal characteristics of alluvium and riverbed in domestic area. In this research, state-of-the-art thermal line temperature sensor monitoring was introduced. And long term field test using this type of sensor was performed to find geothermal characteristics of alluvium and riverbed and evaluate the availability for heat energy source. As a result, temperature monitoring technique through thermal line sensor was very effective to obtain basic geothermal information of alluvium deposit and riverbed. Also, it was found that the groundwater temperature phase showed its potential of utilization as a energy source of heat pump. It is estimated that further study shows a specific corelation between temperature monitoring data and its availability as a energy source.

• International Journal of Ocean System Engineering
• /
• v.1 no.1
• /
• pp.46-51
• /
• 2011

In a line heating process for hull forming, the phase of the steel transforms from austenite to martensite, bainite, ferrite, or pearlite depending on the actual speed of cooling following line heating. In order to simulate the water cooling process widely used in shipyards, a heat transfer analysis on the effects of impinging water jet, film boiling, and radiation was performed. From the above simulation it was possible to obtain the actual speed of cooling and volume percentage of each phase in the inherent strain region of a line heated steel plate. Based on the material properties calculated from the volume percentage of each phase, it should be possible to predict the plate deformations due to line heating with better precision. Compared to the line heating experimental results, the simulated water cooling process method was verified to improve the predictability of the plate deformation due to line heating.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
• /
• v.4 no.1
• /
• pp.177-197
• /
• 1998

This experimental study was carried out to evaluate the effect of Yipahnsan on angiogenic inhibition mechanism. This study investigates the effects of Yipahnsan on angiogenic inhibition mechanism evaluate cell adhesive inhibition effect, DNA fragmantaion analysis, nuclear condensation assay, FACScan analysis, angiogenic lumen formation assay, immunocytochemistry analysis, RT-PCR for mRNA expression, western blot analysis, confocal analysis for $Ca^{2+}influx$. The results were summarized as follows : 1. The cell adhesive inhibition ability was strongly increased from $5{\mu}g/ml$ on ECV304 cell line and ECVPAR cell line. 2. YY water extract caused $G_0/G_1$ arrest peak to existed on the ECV304 cell line. 3. YY water extract caused inhibition of proliferation and inducement of apoptosis on the collagen coated plate in ECV304 cell line. 4. YY water extract inhibited the lumen formation on the matrigel coated plate in ECV304 cell line. 5. YY water extract inhibited the expressions of LFA-1 and ELAM-1 on ECV304 cell line and ECVPAR cell line. 6. YY water extract inhibited the expressions of MMP-9 and uPA on ECV304 cell line and ECVPAR cell line. 7. YY water extract inhibited the expression of integrin ${\alpha}_v{\beta}_3$ on ECV304 cell line and ECVPAR cell line. 8. YY water extract decreased the change of $Ca^{2+}$ in intracellular on ECV304 cell line and ECVPAR cell line. According to the results, Yipahnsan showed to be a key antagonist of integrin ${\alpha}_v{\beta}_3$, and to be induction of apoptosis by p53 through flow cytometry. This report also demonstrated that expressions of MMP-9 and uPA were blocked under the angiogenesis model. Thus, we suggested that Yipahnsan blocks angiogenesis by inducing apoptosis in ECV304 and ECVPAR cell lines, and another oriental herbal medicine that treats qi-stagnation and blood-stasis type also has angiogenic inhibition effects.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.4
• /
• pp.299-307
• /
• 2016

This study aims to investigate effects of the length of the buoy and sand bag line on the loss of webfoot octopus pot. A numerical modeling and simulation was carried out to analyze the process that the pot gear affected by wave using the mass spring model. Through the simulation, tensions of sand bag line under various condition were investigated by length of buoy and sand bag line. The drag force and coefficient k of an artificial shell used in the webfoot octopus pot was obtained from an experiment in a circular water channel, and the coefficient k was applied to the simulation. To verify the accuracy of the simulation model, a simple test was conducted into measuring a rope tension of a hanging shell under flow. Then, the test result was compared with the simulation. The lengths of the buoy line in the simulation were 1.12, 1.41, 1.80, 2.23, 2.69, and 3.17 times of water depth. The lengths of sand bag line were 10, 20, 30, and 40 meters, and conditions of water depth were 8, 15, 22 meters. 4 meter height and 8 second period of wave were applied to all simulations. As a results, the tension of the sand bag line was decreased as the buoy and sand bag line were increased. The minimum tension of the sand bag line was appeared in conditions that the length of the buoy line is twice of water depth and the sand bag line length is over 40 meters (except in case of depth 8 meters.).

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3755-3759
• /
• 2010

A on-line SPE (solid phase extraction)-HPLC preconcentration method was developed for the determination of phenolic compounds at trace levels in environmental water sample. XAD-4 and Dowex 1-X8 were used as sorbent in the on-line SPE-HPLC method for the selective enrichment of nine phenolic compounds, which are included in the priority pollutants list of the US EPA. Also alumina prefiltering considerably reduced the amount of interfering peaks due to humic substances that could accumulated due to the preconcentration step and prevent quantification of polar phenolic compounds in environmental water samples. This method was used to determine the phenolic compounds in tap and river water and superiority to the US EPA 625 method in its enrichment factor, pretreatment time, recoveries, and detection limit. The limits of detection were in the range of $0.3-0.9\;{\mu}g/L$ in tap water sample.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.75-85
• /
• 2006

In recent geotechnical engineering, geothermal approach has been on the horizon to deal with geoenvironmental issues, freezing and thawing problems, and seepage phenomenon in dams and embankments. In this study, geothermal characteristic through inner body of dams and its influence on the seepage flow were experimented by lab test and field instrumentation. Also, one of up-to-date temperature monitoring technique, called as multi-channel thermal line sensing, was evaluated its availability. As a result of lab test, it is found that the seepage flow has influence on the geothermal characteristic and a potential of finding phreatic line and seepage fluctuation could be possible by continuous temperature monitoring using thermal line sensing skills. These kine of geothermal information could be available to the modelling of water geo-structure interaction. Out of short-term field tests, clear water table and temperature distribution of a dam were easily found through temperature monitoring in holes located near a reservoir and holes within a depth of constant temperature layer. However, it is also found that the geothermal flow and finding seepage line could not be easily understandable through multi-channel temperature monitoring because of the existence of constant temperature field, thermal conductivity of soils and rocks, and unsaturated characteristics of geo-material. In this case, long-term geothermal monitoring is recommended to find sudden fluctuation of seepage line and amount of leakage.