• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1512-1517
• /
• 2008

Laboratory column tests were conducted in this study using $Cl^-$ tracers on Jumunjin sand to analyze contaminant transport in mixed contaminated soils. Results obtained from clean soils and soils containing residual diesel verified heterogeneous distribution of residual diesel, and clear acceleration of solute movement. In addition, asymmetric breakthrough curves indicated development of immobile region where solute movement becomes stagnant and creates tailing phenomenon.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.11
• /
• pp.4664-4670
• /
• 2010

Comparison of the classical mobile-immobile zone (MIM) model to the derived model led to several conclusions. If the MIM model is to be applied, the initial concentration in the immobile zone has to be down-scaled by a correction factor that is a function of pore geometry. The MIM model was valid only after sufficiently long time has passed, i.e., only after the diffusion front reaches the deepest pore wall in the immobile zone. The MIM mass-transfer coefficient $\alpha$, was inversely proportional to the square of the pore depth. Also it did not depend on the mobile-zone flow velocity, contrary to the number of laboratory and field observations. The classical MIM model displayed a rapid exponential decay of immobile-zone concentration. Meanwhile at large times, the newly derived model displayed similar exponential decay. This was contrary to the mounting evidence of power-law BTC tails observed in laboratory and field settings.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.2
• /
• pp.99-103
• /
• 2010

A new analytic solution was derived for the diffusion into or from an immobile zone of a rectangular 2-D pore. For a long time, the new solution converges to a traditional mobile-immobile zone (MIM) model, but only if the latter is used with an apparent initial concentration that is smaller by almost 20% than the true one. This is the tradeoff for using a simple MIM model instead of an exact model based on the diffusion equation. The mass-transfer coefficient was found to be constant for a sufficiently long time; it was proportional to the molecular diffusion and inversely proportional to the square of the pore depth. The mass-transfer coefficient was time-dependent for a sufficiently short time and may be significantly larger than its asymptotic value.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.5
• /
• pp.31-39
• /
• 2012

Chemical and isotopic variations of snowmelt provide important clues for understanding snowmelt processes and the timing and contribution of snowmelt to catchment or watershed in spring. The newly developed model includes a hydraulic exchange between mobile and immobile water (${\omega}$), and isotopic exchanges between both mobile water and ice ($f_1$) and immobile water and ice ($f_2$). Since the new model is based on the mobile-immobile water conceptualization, which is widely used for describing chemical tracer transport in snow, it allows simultaneous calculations of chemical as well as isotopic variations in snowpack discharge. We compare the model results with a study of solute transport and isotopic evolution of snowmelt in snow, using artificial rain-on-snow experiments with conservative anion ($Br^-$). These observations are used to test the newly developed model and to better understand physical processes in a seasonal snowpack where our model simulates the chemical and isotopic variations.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.2 no.1
• /
• pp.23-33
• /
• 1984

Color providing compounds on image transfer process in color photo graphy was studied with polaroid and Kodak products as a model. These compounds was inititally alkali-mobile or alkali-immobile. Alkali-mobile compunds require imagewise immobilifation in the process or alkali immoble compounds require mobilization by the cleavage reaction. As a result of studies, the polaroid products was showed alkali mobile and Kodak product represented alkali immobile.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.23 no.6
• /
• pp.651-657
• /
• 2010

Solute transport through a groove is affected by its vortices. Our laboratory and numerical experiments of dye transport through a single axisymmetric groove reveal evidence of enhanced spreading and mixing by the vortex, i.e., a new kind of dispersion called here the vortex dispersion. The uptake and release of contaminants by vortices in porous media is affected by the flow Reynolds number. The larger the flow Reynolds number, the larger is the vortex dispersion, and the larger is the mass-transfer rate between the mobile zone and the vortex. The long known dependence of the mass-transfer rate between the mobile and "immobile" zones in porous media on flow velocity can be explained by the presence of vortices in the "immobile" zone and their uptake and release of contaminants.

• Economic and Environmental Geology
• /
• v.45 no.5
• /
• pp.525-533
• /
• 2012

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

• Korean Journal of Health Education and Promotion
• /
• v.25 no.4
• /
• pp.55-65
• /
• 2008

Objective: This study aims to investigate the relationship between dental status and oral function by analyzing those in some long-term care elderly patients. Methods: It performed oral examination and 4 oromotor function examinations such as repeated swallowing function, correct pronunciation function, saliva secretion rate and maximum mouth opening to 91 elderly patents aged 65 and older in the municipal geriatric hospital located in Cheonan. Results: Dental status of patients such as the number of dental caries, treated teeth, retained teeth and function teeth were better in mobile elderly patients than in immobile elderly patients. Attachment rate of dental plaque and the number of teeth being extracted were more in mobile patients than in immobile patients. More retained teeth, the number of function teeth and dental caries and the score in pronunciation status test were significantly higher. With more function teeth, the score in pronunciation status test was significantly higher. As saliva secretion rate is higher, repeated swallowing function was significantly better. repeated swallowing function rate is higher pronunciation status was significantly better. Conclusions: With the results of this study, it was found that among long-term care elderly patients, oral function was worse in immobile patients than in mobile patients. Therefore, it may be necessary to plan and perform an oral function improvement program preferentially for elderly patients requiring long-term care.

• Journal of Environmental Science International
• /
• v.19 no.5
• /
• pp.549-563
• /
• 2010

The environmental behaviors of polycyclic aromatic hydrocarbons (PAHs) are mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation (SER) systems, surfactant plays a critical role in remediation. In this study, sorptive behaviors and partitioning of naphthalene in soils in the presence of surfactants were investigated. Silica and kaolin with low organic carbon contents and a natural soil with relatively higher organic carbon content were used as model sorbents. A nonionic surfactant, Triton X-100, was used to enhance dissolution of naphthalene. Sorption kinetics of naphthalene onto silica, kaolin and natural soil were investigated and analyzed using several kinetic models. The two compartment first-order kinetic model (TCFOKM) was fitted better than the other models. From the results of TCFOKM, the fast sorption coefficient of naphthalene ($k_1$) was in the order of silica > kaolin > natural soil, whereas the slow sorbing fraction ($k_2$) was in the reverse order. Sorption isotherms of naphthalene were linear with organic carbon content ($f_{oc}$) in soils, while those of Triton X-100 were nonlinear and correlated with CEC and BET surface area. Sorption of Triton X-100 was higher than that of naphthalene in all soils. The effectiveness of a SER system depends on the distribution coefficient ($K_D$) of naphthalene between mobile and immobile phases. In surfactant-sorbed soils, naphthalene was adsorbed onto the soil surface and also partitioned onto the sorbed surfactant. The partition coefficient ($K_D$) of naphthalene increased with surfactant concentration. However, the $K_D$ decreased as the surfactant concentration increased above CMC in all soils. This indicates that naphthalene was partitioned competitively onto both sorbed surfactants (immobile phase) and micelles (mobile phase). For the mineral soils such as silica and kaolin, naphthalene removal by mobile phase would be better than that by immobile phase because the distribution of naphthalene onto the micelles ($K_{mic}$) increased with the nonionic surfactant concentration (Triton X-100). For the natural soil with relatively higher organic carbon content, however, the naphthalene removal by immobile phase would be better than that by mobile phase, because a high amount of Triton X-100 could be sorbed onto the natural soil and the sorbed surfactant also could sorb the relatively higher amount of naphthalene.

• Asian Journal of Turfgrass Science
• /
• v.8 no.2
• /
• pp.101-103
• /
• 1994

In June 1994, the circular parch of zoysiagrasse(Zoysia japonica) occurred in golf courses in Kyeongnam, Kycooggi province, Korea The causal agent identified as Antonina graminis Maskell (Rhodeagrass scale). A. gramninis settle on a grass leaf shearh and stem, and then suck plants juices, causing daroaged plants to wither and die. Adult scales were legless, immobile, and shell-like protective cover with waxy and 2~Amm in size. Immature scales had three pairs of leg, and were mobile, O.4~ O.9mm in size.