• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.617-623
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• 2015

In this study, determination methods of monitoring location in water distribution system were suggested and applied to real test bed. Small block of Gwangtan water distribution system is consisted of 582 pipes, 564 junctions, 1 reservoir, and 1 pump station. Small block of Ho Chi Minh water distribution system is consisted of 162 pipes, 148 junctions, and 1 reservoir. Two small block water distribution systems were analyzed by pressure contribution analysis method to determine the optimum monitoring locations. The pressure change was estimated at each junctions by the additional demand at a junction. From the results, the optimum monitoring location can be determined by rank of pressure contribution index at each junctions due to demand change at a junction.

• Ecology and Resilient Infrastructure
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• v.4 no.4
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• pp.187-192
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• 2017

This study evaluated the reduction performance of ambient temperature and the amount of evaporation that takes place depends on the temperature difference of paving blocks which are used in the sidewalk, roadway, parking lot, park, plaza, and etc. The water-retentive block of the LID (Low Impact Development) practice was compared with the conventional concrete block. For the quantitative performance evaluation, experiments were performed in a climatic environment chamber capable of controlling the climatic environment (solar radiation, temperature, humidity, rainfall, and snowfall). The method for performance evaluation was proposed using temperature, humidity, and ambient air of paving blocks which changes according to the solar radiation and the wind speed after the rainfall. As a result, the evaporation amount of the water-retentive block was 2.6 times higher than that of the concrete block, the surface temperature of water-retentive block was $10^{\circ}C$ lower than the concrete block, and the air temperature of water-retentive block was $4.6^{\circ}C$ lower than the concrete block. Therefore, it is analyzed that the water-retentive block with a large amount of evaporation is more effective in reducing the urban heat island phenomenon as compared with the concrete block.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.2
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• pp.179-182
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• 2007

In this study hydraulic model experiment was conducted to identify the performance of newly developed water affinity sea-wall block to keep the coastal line from eroding and supply water affinity space by reflection coefficient and safety. In the result, the block is applicable to the field.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.47-54
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• 2016

This study is a basic research on the functional performance review for the use of environmentally friendly construction materials as lapilli-bio block. The neutralization processed Mt. Backdusan and Mt. Hallasan lapilli-bio block were identified vegetation characteristics and water purification properties. As a result, the adsorption of root was more favorable, depending on the material properties of many voids Lapilli. And if the neutralization processed lapilli-bio blocks maintain a long-term immersion conditions in contaminated water was found to be expected from the improvement effect of SS, T-N and T-P. However, field trials and continuous studies are expected to be identified by the use of lapilli-bio block.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1649-1655
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• 2009

The antioxidant activities of water extracts from wild vegetables such as Ligularia fischeri (GC), Capsicum annuum L. (GCY), Aster scaber (CNM), Petasites japonicus S. et Z. Max (MYD), Ipomoea batatas L. (Lam) (GGM) were evaluated and compared with water extracts from freeze dried block. The antioxidant properties of water extracts from wild vegetables and their freeze dried block were evaluated using different antioxidant tests; 2.2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and nitrite scavenging activities. The water extracts from wild vegetables were found to have a higher total phenolic content than water extracts from freeze dried block. Total phenolic contents of water extracts from GC, GCY, CNM, MYD, and GGM were $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;{\mu}g/mg\;and\;122.67{\pm}3.51\;{\mu}g/mg$, respectively. At the concentrations of 1000 ppm, water extracts from GC, GCY, CNM, and GGM showed higher activities than water extracts from their freeze dried block on DPPH radical scavenger activity. The activity of water extracts from CNM, GC, GCY, MYD, and GGM were 90.9%, 89.9%, 76.6%, 71.1%, and 57.4%, respectively. When 10000 ppm of GC, GCY, CNM, MYD, and GGM water extracts tested for hydroxyl radical scavenging activity, activities were increased by 38.8%, 33.4%, 35.9%, 34.3%, and 33.8%, respectively and a similar effect was found with water extracts from GCY, CNM, and GGM freeze dried block at 10000 ppm concentration. However, the water extracts from GC and MYD was slightly more effective than freeze dried block extracts. The water extracts from wild vegetables and their freeze dried block had effective DPPH radical scavenger activity and hydroxyl radical scavenging activity at all tested concentrations. Nitrite scavenging activity of GC water extract significantly increased in a dose-dependent manner and the extract had higher nitrite scavenging activity than extracts freeze dried block extracts. We found that freeze dried block maintained antioxidant activities of the wild vegetables.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.370-374
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• 2016

We investigated the three dimensional turbulent flow characteristic around a sidewall-mounted rectangular block using a laboratory flume experiment. The experiment was conducted in the flume which is 18m long and 0.9m wide, and a rectangular block that is 0.3m wide and a height of 0.4m and 0.004m thick is mounted on a sidewall of the flume. Velocity data were collected using Acoustic Doppler Velocimeter(ADV) for the flow rate conditions : $0.0528m^3/s$. The time-averaged velocity and water depth data were analyzed to examine the three-dimensional flow patterns downstream of the rectangular block.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.87-97
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• 2008

This research focused on development and application feasibility for the coalesced continuous block system in river bank protection. Most of block systems in river bank are pre cast type and have some difficulties against high velocity flood condition or high pressure load, however, the continuous block system can be applied to flood damage recover as well as environmental vegetation block system in river bank. For the application review and analysis of hydraulic condition for this block system, hydraulic physical modeling was carried out. The physical model was built as a scale of 1:50 by Froude similitude measuring the water levels and the water velocities for vegetation application or not. In consequence, the water velocities were observed to decrease meanly 10.1%, and the water depths were to increase meanly 17.8% in case of the of design flood, $Q=200m^3/sec$. To verify the hydraulic physical modeling, the numerical modeling should be conducted for a close examination of vegetation application by one or two dimensional numerical analysis as a next study.

• Explosives and Blasting
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• v.35 no.4
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• pp.19-26
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• 2017

The most widely used method for determining the blast effects of explosives is the Trauzl lead block test. This test is used to measure the explosive power (strength) of a substance by determining volume increase, which is produced by the detonation of a test explosive charged in the cavity of a lead block with defined quantity and size. In this paper, Trazul lead block test and AUTODYN numerical analysis were conducted to evaluate the coupling medium effect of blast hole. The effects of coupling materials can be expressed as the expansion of the cavity in a standard lead block through explosion of the explosives. The tests were conducted with emulsion explosives. The coupling mediums used as the filling material around a explosive charge were air, sand, water and gelatine. Results of test and numerical analysis showed that expansion of lead block were much more affected by water&gel than by sand and air. The water and gel showed similar results. As expected, the transmitted pressure and dynamic strain was higher in water and gelatine coupled blast hole than in air and sand.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.71-76
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• 1998

Water management objects was developed using the Object Oriented Programming (OOP) concept and Irrigation Block Simulation Model was developed using these objects. This model using OOP can simulate the behavior of the irrigation block composed of several irrigation canals, drainage canals, paddy fields, check gates, and so on. This study showed that using OOP concept, we can develop an water management application or extend the function of existing application more easily.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.167-173
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• 2018

In general, calcium is required for the reaction of blast furnace slag fine powder and fly ash. The by-products generated during the process of producing recycled aggregates have different calcium contents depending on the crushing stage and the possibility of using the process by-product as a concrete mixture is also different. In this study, the effect of the calcium content of the by-products on the compressive strength was investigated and the block was fabricated by using this. To utilize the by-products as an admixture, the calcium content was analyzed and the bending strength and surface temperature were measured according to the shape of the water storage block. As a result of this study, the possibility of making a block using recycled aggregate by-products was verified and arch type block was constructed to secure storage capacity and bending strength. Also, the surface temperature of the water storage block was reduced by $9^{\circ}C$ or more than that of the general permeable block.