• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• 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.

• 한국산학기술학회논문지
• /
• 제11권11호
• /
• pp.4664-4670
• /
• 2010

본 연구에서는 기존 MIM Zone model과 새로이 유도한 모델과 비교를 통해 몇가지 결론을 도출하였다. MIM model 이 적용되면 immobile 영역에서의 초기농도는 기공의 형태에 의해 달라지는 보정계수에 의해 실제농도보다 저평가되었으며 이는 오직 확산이 기공의 가장 깊은 부분까지 시행된 이후에 유효함을 확인하였다. 물질이동계수, $\alpha$는 기공의 깊이에 따라 반비례하며, 유동 구역의 유속에는 종속되어지지 않는다. 기존의 MIM model 은 확산주도영역의 농도가 급속하게 감소하는 현상을 보여주는데 새로이 유도된 모델의 경우도 충분한 시간이 경과한후 비슷한 현상을 보였으며 이는 기존의 여러 실험에서 관찰된 power-law BTC 의 상반되는 결과를 보여준다.

• 대한기계학회논문집B
• /
• 제34권2호
• /
• pp.99-103
• /
• 2010

다공성 매질상에서 유체와 용질의 이동은 Mobile zone과 Immobile zone으로 분리해서 분석하는 Mobile-Immobile Zone Model을 이용하여 쉽게 현상을 구현할 수 있었으나 본 연구에서는 2차원 4각형태의 pore 상에서 확산주도영역(Immobile zone)으로 들어가고 나오는 용질의 확산에 관한 새로운 Analytic solution을 유도하여 기존 MIM Zone model과 비교 분석하였다. 새롭게 유도된 Analytic solution은 기존의 MIM model 과 비교했을때 충분히 오랜시간이 경과한 후에는 해의 일치를 보이지만 MIM model의 경우 초기 농도값이 주입된 실제 농도보다 약 20 % 낮게 나타난다. Mass-transfer 계수, $\alpha$는 일반적으로 시간의 흐름에 따라 감소하게 되는데 일정 시간이 경과하게 되면 안정화 되고 일정함을 유지하며 그 시간은 무차원으로 약 ${\tau}_0=0.15$이다. 또한 $\alpha$는 분자확산과 비례하며 Immobile 영역의 깊이와 반비례하는 반면 작은 시간이 경과한 후에는 시간에 종속되어진다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권5호
• /
• 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.

• 한국인쇄학회지
• /
• 제2권1호
• /
• pp.23-33
• /
• 1984

천연색 사진에서 전사과정중 발색화합물을 Polaroid 사 제품과 Kodak사 제품을 선정하여 고찰하였다. 이들 화합물은 초기에 Alkali 가동이거나 불가동이었다. Alkali 가동 화합물은 분해에 의하여 상적으로는 불가동화가 요구되며 Alkali0불가동 화합물은 상적으로 가동화가 요구된다. 고찰겨과 Polaroid사 제품은 Alkali 가동을 나타내며 Kodak제품은 Alkali불가동을 나타냇다.

• 한국전산구조공학회논문집
• /
• 제23권6호
• /
• 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.

• 자원환경지질
• /
• 제45권5호
• /
• pp.525-533
• /
• 2012

겨울철동안 쌓여 봄에 놓은 눈 녹은 물(snowmelt), 즉 융설의 유출은 북반구 및 산간지역에서 매우 중요한 것으로 여겨지고 있다. 이러한 지역에서 융설로 인한 유동 및 이온의 이동에 대한 이해는 매우 중요하며 전세계적으로 꾸준하게 연구되고 있다. Lee et al. (2008a)와 Lee et al. (2008b)연구에서는 대기로부터 수송된 이온 및 오염원이 융설에 의해 눈속을 이동하는 것을 모사하기 위한 Mobile-Immobile water Model (MIM)을 개발하였다. 이 연구에 사용된 모델을 검증하기 위해서 물질수지계산(mass balance calculation) 및 해석해(analytical solution)를 이용한 모델결과와의 비교를 수행하였다. 일정시간동안 눈 속에서의 물질의 질량변화는 눈 표면에서 들어온 물질과 눈 기저부에서 빠져나간 물질의 질량 차이와 같아야한다는 사실을 이용하여 물질수지를 계산하였다. 파면(wave front)의 이동속도 및 기존문헌에서 알려진 해석 해를 이용하여 모델결과와의 비교도 시도하였다. 모델의 물질수지계산결과 질량 차이가 거의 발생하지 않았으며 모델결과와 해석해와의 비교 역시 두 결과가 거의 일치하였다.

• 보건교육건강증진학회지
• /
• 제25권4호
• /
• 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.

• 한국환경과학회지
• /
• 제19권5호
• /
• 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.

• 아시안잔디학회지
• /
• 제8권2호
• /
• 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.