• Geomechanics and Engineering
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• v.6 no.1
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• pp.47-63
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• 2014

In this paper, asymmetric drainage boundaries modeled by exponential functions which can simulate intermediate drainage from pervious to impervious boundary is proposed for the one-dimensional consolidation problem, and the solution for the new boundary conditions was derived. The new boundary conditions satisfy the initial and the steady state conditions, and the solution for the new boundary conditions can be degraded to the conventional solution by Terzaghi. Convergence study on the infinite series solution showed that only one term in the series is needed to meet the precision requirement for larger degree of consolidation, and that more terms in the series for smaller degree of consolidation. Comparisons between the present solution with those by Terzaghi and Gray are also provided.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.8
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• pp.1085-1096
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• 2000

An experimental study was performed to examine the heat and mass transfer characteristics of $LiBr-H_2O$ solution flowing over a single horizontal tube with the water vapor absorption. Effects of the flow rate and the temperature of the solution at the top of the tube, the absorber pressure and the drainage pattern were considered. The absorption rate depends highly on the absorber pressure at the low flow rate condition while on the solution inlet temperature at the high flow rate condition. Also, when the flow rate is low, the absorption performance with the sheet flow drainage appeared to be higher than that with the dripping/jet drainage. However, at the high flow rate condition, the case became reversed. The liquid film became wavy with the higher absorption rate. The waves were more probable to form with the lower flow rate and temperature of the solution, and with the higher absorber pressure.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.3
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• pp.181-192
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• 2012

Here in this paper, the steady paint film flow on a vertical wall of a non-Newtonian pseudo plastic fluid for drainage problem has been investigated. The exact solution of the nonlinear problem is obtained for the velocity profile. Also the average velocity, volume flux, shear stress on the wall, force to hold the wall in position and normal stress difference have been derived. We retrieve Newtonian case, when material constant ${\mu}_1$ and relaxation time ${\lambda}_1$ equal zero. The results for co-rotational Maxwell fluid is also obtained by taking material constant ${\mu}_1$ = 0. The effect of the zero shear viscosity ${\eta}_0$, the material constant ${\mu}_1$, the relaxation time ${\lambda}_1$ and gravitational force on the velocity profile for drainage problem are discussed and plotted.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.63-69
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• 2001

The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

• Journal of Korean Neurosurgical Society
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• v.40 no.1
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• pp.38-39
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• 2006

Perioperative lumbar drainage of cerebrospinal fluid is commonly used in neurosurgical practice. However, the relationship between lumbar drainage and acquired Chiari malformation is not well established. The authors present an unusual case of paraplegia as a result of acquired Chiari malformation after lumbar drainage. Acquired Chiari malformation can induce compression of cervicomedullary junction and syrinx formation. Foramen magnum decompression is recommended for the solution of such problems.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.25-33
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• 1999

A great difference in drainage time was observed from the recycled stocks between corrugated container board and its component papers, liner and medium paper. It could be assumed that the different drainage property should be caused from a starch adhesive present in the corrugated board. Thus, three types of starch such as dried Stein-Hall adhesive, cooked starch solution, and its dried film were added to linerboard stock in order to investigate the mechanism of drainage reduction. The water-swollen starch particles derived from Stein-Hall adhesive were drastically deteriorated the drainage time, even though the amount of starch is very small (2% or below). The drainage time of OCC was improved by 25% when amylase was used a new biological treatment. The results from the lab and mill test showed that the starch-degradable enzymatic treatment improves the drainage property as well as the reduction of calcium hardness.

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.12-21
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• 2017

A pot experiment was conducted to investigate the transfer of As and cationic heavy metals (Fe, Mn, Zn, Cd and Pb) from soil to rice plant in soil condition with submerged and drained. During the ninety-day monitoring period for soil solution, solubility of reducible elements such as As, Fe and Mn in submerged condition were higher than that of Zn. On the contrary, concentration of Zn in drained condition was higher than that of reducible elements. The concentration of As, Cd, Pb and Zn in rice plant (root, stem, leaf and grain) showed similar pattern with soil solution. The As concentration in each part of rice plant, which cultivated in drained condition, measured 56%~94% lower than those in submerged condition. However, the contents of cationic heavy metals (Cd, Pb and Zn) were represented the opposite result with As. These results are due to mobility of As and cationic heavy metals under different soil drainage conditions which represent oxidation and reduction. Thus soil drainage control can be used as acceptable passive treatment methods to reduce transfer of inorganic contaminants from soil to rice plant. However more detailed examination on soil condition conversion is needed, because yield of rice was decreased when it cultivated in drained condition only. It also needed when soil is contaminated by As and cationic heavy metal because single drainage condition cannot reduce transfer of both kinds of contaminants all.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.297-302
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• 2011

Acid drainage generated by pyrite oxidation has caused the acidification of soil and surface water, the heavy metal contamination and the corrosion of structures in abandoned mine and construction sites. The applicability of Na-acetate (Na-OAc) buffer and/or Na-silicate solution was tested for suppressing pyrite oxidation by reacting pyrite containing rock and treating solution and by analyzing solution chemistry after the reaction. A finely ground Mesozoic andesite containing 10.99% of pyrite and four types of reacting solutions were used in the applicability test: 1) $H_2O_2$, 2) $H_2O_2$ and Na-silicate, 3) $H_2O_2$ and 0.01M Na-OAc buffer at pH 6.0, and 4) $H_2O_2$, Na-silicate and 0.01M Na-OAc buffer at pH 6.0. The pH in the solution after the reaction with the andesite sample and the solutions was decreased with increasing the initial $H_2O_2$ concentration but the concentrations of Fe and $SO_4^{2-}$ were increased 10 - 20 times. However, the pH of the solution after the reaction increased and the concentrations of Fe and $SO_4^{2-}$ decreased in the presence of Na-acetate buffer and with increasing Na-silicate concentration at the same $H_2O_2$ concentration. The solution chemistry indicates that Na-OAc buffer and Na-silicate suppress the oxidation of pyrite due to the formation of Fe-hydroxide and Fe-silicate complex and their coating on the pyrite surface. The effect of Na-OAc buffer and Na-silicate on reduction of pyrite oxidation was also confirmed with the surface examination of pyrite using scanning electron microscopy (SEM). The result of this study implies that the treatment of pyrite containing material with the Na-OAc buffer and Na-silicate solution reduces the generation of acid drainage.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.3
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• pp.132-148
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• 2021

The modified F-expansion method is used to construct analytical solutions of the foam drainage equation with time- and space-fractional derivatives. The conformable derivatives are considered as spacial and temporal ones. As a result, some analytical exact solutions including kink, bright-dark soliton, periodic and rational solutions are obtained.

• Fire Science and Engineering
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• v.22 no.5
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• pp.83-89
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• 2008

Using the high expansion foam generator of ISO 7203-2 which spray 6 liter at 5 bar, foam generation characteristics was studied. Wind flow rate, foam screen, concentration of foam agent solution and concentration of salt of water were varied to find the effect of the parameters on foam generation. Research result showed that expansion ratio of foam was increased with wind flow rate. The expansion ratio of foam in the perforated type standard screen was higher than the wire mesh screen. Expansion ratio and drainage time were increased with increase of foam solution concentration. But a increase of salt concentration in solution showed the decrease of expansion ratio and drainage time.