• KOREAN JOURNAL OF CROP SCIENCE
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• v.13
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• pp.77-81
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• 1973

The experiment was carried out to make clear the root characters and relationships among some quantitative characters of soybeans. The results obtained are summarized as follows: 1. Stem diameter was shown the greater growing in thickness after one month from sowing than the earlier stage, and the greater growing was shown in fertile bed soil than in sand soil. 2. The elongation of plant top in soybean plant was also shown the greater rate in bed soil than in sand soil 3. The length of plant root was longer than the length of plant top in the earlier stage of growing, and the length of root was much greater in sand soil than in fertile bed soil. 4. Weight of plant top was shown more in bed soil than in sand soil, but this tendency was shown more greater rate in the length of plant top than in weight of plant top. 5. Weight of root was more compared with weight of plant top in the earlier stage of growth, and also more greater rate was shown in sand soil than in fertile bed soil. 6. Highly significant correlations were shown among five quantitative characters, namely stem diameter, length of top, weight of top, length of root and weight of root, etc.

• Journal of Advanced Research in Ocean Engineering
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• v.2 no.1
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• pp.22-27
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• 2016

This experimental study deals with the mechanism of spoilers that cause scouring around pipelines. The design methodology was applied to spoilers for accelerating pipelines that undergo self-burial into the sand-bed and evaluated using approaching experimental analysis. The experimental study was conducted to investigate the self-burial ability of submarine pipelines with two types of sand-bed models: silt and sand. Spoilers of different heights were attached to the top of the pipeline for each experiment case. The relationship between the relative scour depth and spoiler height was evaluated by applying different flow velocities and sand diameters and comparative analysis was performed with values obtained from similarity experiments and theory. The experimental study will be useful in establishing a database for the design of spoilers.

• Journal of agriculture & life science
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• v.44 no.4
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• pp.29-43
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• 2010

The numerical analysis by using CFX 11.0 commercial code was done for proper design of the heat exchanger. The present experimental studies were also conducted to investigate the effects of circulating solid particles on the characteristics of fluid flow, heat transfer and cleaning effect in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which a variety of solid particles such as glass ($3mm{\Phi}$), aluminum ($2{\sim}3mm{\Phi}$), steel ($2{\sim}2.5mm{\Phi}$), copper ($2.5mm{\Phi}$) and sand ($2{\sim}4mm{\Phi}$) were used in the fluidized bed with a smooth tube. Seven different solid particles have the same volume, and the effects of various parameters such as water flow rates, particle diameter, materials and geometry were investigated. The present experimental and numerical results showed that the flow velocity range for collision of particles to the tube wall was higher with heavier density solid particles, and the increase in heat transfer was in the order of sand, copper, steel, aluminum, and glass. This behavior might be attributed to the parameters such as surface roughness or particle heat capacity.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.112-118
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• 2012

Fine suspended solids from mine drainage draw attentions due to their potential adverse influences on the water quality, such as increasing turbidity and degrading aesthetic landscape. Currently, sand filter beds are adapted in some mine drainage treating systems. However, more efficient system is in demand, as the existing sand beds reveal some problems, such as frequent maintenance intervals. Various filtering mediums including fly ash, mine tailing aggregates and the sand were tested for improving the current system, using column experimental set-up. Mine drainage samples were collected from the current treating systems in the abandoned H coal mine. The experiment was run for 7 days. Suspended solids recorded as 100.9 mg/L and the value exceeds the current standard, 30 mg/L. Sand was proved to still be the optimum medium for the fine suspended solids, compared to fly ash and fly ash + sand. Mine tailing aggregates were placed at the exit of the columns, substituting gravels. The tailing aggregates is made by mine tailings and clay. Sand bed filters can also be improved by mixing granular activated carbon, which was found to be economical and efficient in the batch experiment, conducted at the same time.

• Water for future
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• v.15 no.4
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• pp.31-37
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• 1982

In this study, the method to determine the values of both bed-sand scale and time scale of movable bed hydraulic model experiments on beach degormation has been proposed and the results of the experiments reveal the verification of the similarity between the proto type and the model.

• 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.

• Solar Energy
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• v.14 no.2
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• pp.51-60
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• 1994

The fluidization characteristics of the furan foundry sand fluidized bed and the heat transfer characteristics on a single spiral coil tube in the bed have been investigated. In the paper, the heat transfer coefficients for a single spiral coil tube are measured in the furan foundry sand bed as a function of the ratio of heated coil tube pitch to diameter(p/Do) and the ratio of heated coil tube pitch to particle size(p/dp). The experimental results are as follows. 1) Mean heat transfer coefficients increases according to the increasing ratio of heated coil tube pitch to diameter(p/Do). 2) The Increasing rates of mean Nusselt numbers are more greater in the case of p/Do=1.58 than p/Do=4.75. 3) Mean Nusselt number can be expressed by the following equation, $Nu_{mean}=C\;Re^m\;Pr_g^{0.4}(p/dp)^n$.

• Proceedings of the Korea Water Resources Association Conference
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• 1985.07a
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• pp.137-154
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• 1985

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.14-24
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• 2006

To develop small-scale sewage treatment apparatus for detached house of agricultural village, a small-scale sewage treatment apparatus by natural purification method that consisted of aerobic and anaerobic bed was constructed. To reduce the area of a sewage treatment apparatus, four different fitter media were used and each filter medium was coarse sand, broken stone, steel slag, and mixed fitter media (coarse sand : broken stone : steel slag = 1:1:1). The efficiency of sewage treatment according to the depth of aerobic and anaerobic bed and the volume ratio of aerobic to anaerobic bed were investigated in small-scale sewage treatment apparatus. The removal rate of pollutants according to the depth of aerobic and anaerobic bed in small-scale sewage treatment apparatus was high in the order of 50 cm < 70 cm < 90 cm. The removal rate of pollutants according to the ratio of aerobic to anaerobic bed in small-scale sewage treatment apparatus was high in the order of 1:1 < 1:2 $\fallingdotseq$ 1:3. Under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P were $98{\sim}99,\;95{\sim}97,\;99,\;65{\sim}66\;and\;96{\sim}99%$ respectively, in small-scale sewage treatment apparatus.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.43-49
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• 2006

Detailed investigations were carried out on the stability of the dredged soil bed against wave actions, aimedat establishing the design method of artificial tidal flats using dredged soil. The soil was dredged at Nagoya port, Japan, and has a mean grain size of 0.013mm. Basic features of artificial dredged soil bed against wave actions were explained from a series of model experiments in a wave flume. The two types of section shapes were employed; one is a horizontal bed and the other is a sloped one. Changes of the bed profile, shear strength, grain size distribution and water content, according to the wave actions, were measured in detail. The cumulative effect of the wave actions, over about one week, was investigated. A dredged soil bed moves withthe wave actions with relatively small wave height. It should be especially. noted that the clay component is dissolved and flown out, away from the surface layer, and consequently the surface layer hardens, as if it is covered with sand. Wren the wave height is gradually increased, the bed is not liquefied and the shear strength of the dredged bed is increased by a wave-induced dissipation of pore pressures in the bed and a decrease of clay component by the wave-induced leakage.