• Title/Summary/Keyword: Sand-Box Experiment

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Nutrient Absorption and Endosperm Consumption in Rice Seedling (벼 육모일수에 따른 양분흡수와 배유양분 소모)

  • Kim, Sang Su;Choi, Min Gue;Lee, Seon Yong;Cho, Soo Yeon;Jun, Byung Tae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.4
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    • pp.405-410
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    • 1996
  • To elucidate the pattern of nutrient absorption and endosperm consumption as the seedling age of rice, Dongjinbyeo was raised in the seedling box with different nitrogen levels. Absorption of nitrogen and phosphorus were high in the order of artificial seed bed soil, sand with N-1g /box and sand without N from 3 and 5 days after seeding but, potassium wasn't significantly different between sand+N-1g /box and sand. Endosperm consumption rate was high in the order of artificial seed bed soil, sand + N-1g /box and sand but, endosperm dependence rate (endosperm consumption /top dry weight) was vice versa. Seedling height and dry weight were higher in the order of artificial seed bed soil, sand+N-1g /box and sand from 3 days after seeding, number of leaves were more from 5 days after seeding in same order.

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Application of sand compaction pile method of row replacement ratio as foundation of the dyke (호안기초로서 저치환율 모래다짐말뚝 공법의 적용)

  • Jin, Sung-Ki;Kim, Bum-Hyung;Kim, Jong-Seok;Im, Jong-Chul
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.472-485
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    • 2008
  • In this study, sand compaction pile method was adopted to improve the soft ground under the permanent dyke, namely west sea dyke of Incheon New Port. The row replacement ratio 30% was applied to consider the ground condition, environmental side and the construction cost of the site. The stability and displacement analysis was carried out by respectively SLOPE/W and PLAXIS 2D program. Based on this analysis, it is found that the safety factor and displacement is within an allowable criteria. The model experiment was carried out using the acryl soil box with $400(H){\times}1200(L){\times}250(W)mm$ to show the displacement of the dyke and behavior of soft ground. Based on this experiment results, it is found that the settlement does not occur from 1 and 2 loading phases and horizontal displacement of 0.0075% occurs from 2 phases. It is also found that the differential settlement occurs 0.05mm corresponding respectively 0.02% and 0.03% of the dyke height(15cm).

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Variation of the Electrical Resistivity with ion Components of Pore Water in the Sand (사질토 간극수의 이온 성분들에 따른 전기비저항값의 변화)

  • Yu, Chan;Yoon, Chun-Gyeong;Lee, Young-Nam;Lee, Yong-Gil
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.185-196
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    • 1999
  • A laboratory experiment was performed to examine the relationship between resistivity and ionic components in the pore water of a sand by using soil resistivity test box and STING-Rl. The resistivity measurement was performed with the concentration changes of ionic components. Also, the resistivity change was evaluated for multiple components. The results showed that the resistivity of Arsenic was less than other heavy metals. In the case of complex components, resistivity ranges depended on the resistivity of components existed in the pore water.

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A Study on the Distribution of Hydraulic Head Along the Lateral in a Pilot-Scale Riverbank Filtration (강변여과에서 파일럿규모 수평집수관의 수두분포 연구)

  • Jeong, Jae-Min;Park, Jae-Young;Lee, Jong-Jin;Kim, Yong-Woon;Kim, Seung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.5
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    • pp.334-339
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    • 2013
  • A pilot-scale sand-box experiment simulating a lateral of collector well used in riverbank filtration was performed, and hydraulic head distributions along the lateral were measured according to the various drawdowns at the well. The results of this experiment were compared to the predicted values obtained using a theory previously developed by Kim in order for its validation. This theory predicts the head loss in a large-scale lateral given the loss in a small-scale one, and to have actual values for comparison, the results from a lab-scale experiment previously performed by Kim were employed. Comparing the experimental values to the extrapolated value indeed confirmed the validity of the theory. A procedure to determine the hydraulic head distribution of a practical-scale lateral was also presented applying the theory to the experimental result of this study in an effort to show the process of lateral design for riverbank filtration.

The Influence of the Volume Contents of Sand in Mortar on the Properties of Self Compacting Concrete (잔골재 용적비가 고유동 콘크리트의 성질에 미치는 영향)

  • Choi Jae-Jin;Yoo Jung-Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.755-758
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    • 2004
  • Self-compactability is defined as a capability of concrete to be uniformly filled and compacted in every corners of formwork by its self-weight without vibration during placing. To evaluate the self compactability of self compacting concrete, the slump flow, the time of slump flow at 500mm and U-box apparatus testing methods are used. In this research, the fresh and hardened properties of self compacting concrete using ground granulated blast furnace slag as a part of cement were investigated for the volume contents of sand in the mortar. The workability, flowing characteristics, air content and compressive strength of concrete were tested and the results were compared with the different volume contents of sand in the mortar. In the experiment, we acquired satisfactory results at the point of flowing characteristics and strengths of self compacting concrete.

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An Experimental Study on the Clogging of Sand Filter in a Model Filtration-Pond (천변여과지 모형에서 여재모래의 폐색현상 실험연구)

  • Jeong, Jae-Min;Kim, Seung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.9
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    • pp.681-685
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    • 2013
  • A pilot-scale sand-box experiment was performed in order to investigate the effect of cross-flow velocity on the clogging of the filter sand in a model filtration pond. The clogging phenomenon was observed during the operation with the cross-flow varied in stages in a range of 0~40 cm/sec, and the experimental result was analyzed using a numerical code. Results showed that the cross-flow velocity in this range had no influence on the development of clogging and that clogging occurred mostly on the filter-surface. It was found that while the production rate decreased from $5m^3/m^2-day$ to $3m^3/m^2-day$ the clogging coefficient of the top 50 cm layer increased up to about 30,000 sec, which corresponded to 87% of the clogging coefficient of the total 2.4 m layer. Of the clogging coefficient of the top 50 cm layer, surface clogging constituted 90% while the other 10% was intermediate clogging. It was also found that the surface clogging increased while the intermediate clogging remained constant as the operation continued, and that filtrate turbidity along the filtration depth remained constant in spite of the increase in clogging.

Analyses of subsurface drainage effects of farmland with respect to pipe and envelop material (관재료 및 피복재료별 농경지 암거배수 효과 분석)

  • 정상옥
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.5
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    • pp.53-61
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    • 1995
  • Analyses of subsurface drainage effects of farmland with respect to pipe and envelop material are made by the laboratory experiments using soil box to give basic information for the subsurface drainage system planning and design. Three different diameter PVC perforated pipes and a mesh pipe are used with envelop materials such as sand, rice bran, and crushed stone. Steady state subsurface drainage flow rate increased as envelop material changed from sand to rice bran and crushed stone. This indicates that as the hydraulic conductivity of the envelop material increases, the drainage flow rate increases. On the other hand, for a given envelop material, the mesh pipe which has the largest openning area shows the largest flow rate while small diameter PVC pipes show small flow rates. This tells that as the openning area and pipe diameter increase, the flow rate increases, too. Therefore, selection of pipe and envelop material should be made in accordance with the design drainage flow rate. Unsteady state subsurface drainage flow rate with respect to time differs for different envelop material. In case the sand was used as an envelop material, the small diameter PVC pipes show larger flow rates than the large diameter PVC pipe and mesh pipe. When the rice bran was used, the mesh pipe shows the largest flow rate, while small diameter pipes show smaller flow rates. In case the crushed stone was used as an envelop material, the large diameter PVC pipe and mesh pipe show larger flow rates, while small diameter pipes show a little bit smaller flow rates. However, the variation of flow rates among different pipes is the smallest when the crushed stone is used. The flow rate curve with respect to the pipe changes little for the crushed stone envelop which has a large hydraulic conductivity, while that changes much for the sand and rice bran envelops. However, it is difficult to draw a consistent relationship between the drainage flow rate and pipe for all the envelop materials. Since the subsurface drainage experiments are made only under the restricted laboratory condition in this study, further study including field experiment is required.

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Effect of the Combination of Coarse Aggregate and Fine Aggregate on the Flowability of Ultra High Strength Concrete (굵은 골재 및 잔골재 변화가 초고강도 콘크리트의 유동특성에 미치는 영향)

  • Lee, Hong-Kyu;Lee, Sun-Jae;Kim, Sang-Sup;Park, Young-Jun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.71-72
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    • 2015
  • As this study is the one related to the ultra high strength concrete essentially used for high rise buildings, it has analyzed on the flowability of ultra high strength concrete according to the variation of coarse aggregate and fine aggregate. The coarse aggregate was planned as two types including Granite Aggregate (GA) and crushed coarse Limestone Aggregate (LA) while fine aggregate was planned as four types including Sea Sand (SS), Limestone Crushed Fine Aggregates (LFA), Electric Arc Furnace Oxidizing Slag Aggregates (EFA) and Crushed Sand (CS) to perform experiment with a total of eight variables. As a result of analyzing slump flow, 500mm concentration time, U-Box and L-Flow, etc. among the characteristics of fresh concrete, a mix using LA+LFA is determined to show high flowability in case of applying ultra high strength concrete.

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A Study on the Applicability of Resistivity Cone for Contaminant Investigation in Farm Land (농경지 오염탐사를 위한 비저항콘의 적용성에 관한 연구)

  • Yu, Chan;Yoon, Chun-Gyeong
    • Journal of Korean Society of Rural Planning
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    • v.5 no.1 s.9
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    • pp.45-55
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    • 1999
  • The applicability of resistivity cone for contaminant investigation in farm land was examined in laboratory and in-situ. To verify the resistivity variations in sand with contaminants, laboratory experiment used soil resistivity test box was performed. Heavy metal and others ions were appeared steep variations in low concentration. Pilot test results were the same as laboratory test results. In the in-situ test used resistivity cone, resistivities of waste landfill layer were low than the common soil layers and resistivities had been difference with concentration of contaminant components. Therefore contaminant investigation in farm land using resistivity cone was expected very effective.

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A Study on the Optimum Design of Horizontal Collectors in Floodplain Filtration (홍수터여과에서 집수관의 최적설계 연구)

  • Pi, Seong-Min;Kim, Seung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.6
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    • pp.430-437
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    • 2012
  • In order to obtain information on the design parameters of the horizontal laterals in floodplain filtration, laboratory-scale sand-box experiments were performed where the head distributions on the laterals and the groundwater profiles were measured according to the change in parameters including lateral diameter, hydraulic conductivity of the sand, water level at the well and raw-water supply rate. Measured data were analyzed using a numerical code in order to identify the discharge intensity distribution along the laterals. It was observed from the result that the lowering of the water level at the well had minimal adverse effect on the performance of the floodplain filtration. Results also elucidated that the low conveyance of the laterals to transmit the filtrate was compensated and supplemented by a natural augmentation in horizontal conveyance through the aquifer when the raw-water supply rate exceeded the adequate recovery rate. With this mechanism, the water quality is expected to improve further since the travel distance through the aquifer is amplified. Based on these findings it can be suggested that the diameter of the lateral used in the floodplain filtration may be smaller than those in riverbank/bed filtration. It was also found that the ratio between the head loss occurring in a lateral and the total head loss in the floodplain filtration was proportional to the exit velocities of the laterals, which may be used to design and/or evaluate the lateral in floodplain filtration.