• 한국패류학회지
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• 제20권2호
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• pp.107-110
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• 2004

The filtration rate and oxygen consumption of Anadara granosa bisenensis were measured at 4 different temperature (10$^{\circ}C$, 15$^{\circ}C$, 20$^{\circ}C$, and 25$^{\circ}C$) and 4 different salinity levels (20, 25, 35, and 40 psu), using an direct method under laboratory conditions. The samples were divided into two groups: a large-sized group (shell length: 34.58 ${\pm}$ 2.23 mm, body weight: 12.43 ${\pm}$ 0.44 g) and a small-sized group (shell length: 20.60 ${\pm}$ 0.85 mm, body weight: 4.41 ${\pm}$ 2.30 g). Filtration rate and oxygen consumption increased with the increase of various temperatures and salinity levels. Also, the filtration rate and oxygen consumption of the small-sized group were higher than those of the large-sized group. These results indicate that the filtration rate and oxygen consumption of Anadara granosa bisenensis depends on environmental conditions, especially on water temperature and salinity.

• Journal of the Korean Wood Science and Technology
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• 제26권4호
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• pp.86-91
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• 1998

The drainage was used to determine the specific filtration resistance for wood and non-wood fibers. The drainage rate is also affected by factors that can be changed on consistency, pressure drop across the mat, basis weight, additives, and viscosity. Recent development of theoretical studies in flow through porous media and filtration operation emphasize the urgent need for more accurate data for porosity and specific filtration resistance. This study was investigated to determine specific filtration resistance of Hw, Sw-BKP and Kenaf fiber by filtration experimental. Freeness levels selected were 150,250,and $350m\ell$ CSF. The average specific filtration resistance decreased as freeness increased and resistance of Sw-BKP was greater than that of Hw-BKP. The filtrate and porosity increased and specific filtration resistance decreased as particle size of fiber increased.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.19-26
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• 2011

In this research, soil analysis and adsorption were conducted, and compared with the water quality of bank filtration and river in terms of TS, TDS, SS, $NH_4$-N, $NO_3$-N, $NO_2$-N, Fe, Mn, BOD and $KMnO_4$ consumption for the development of bank filtration in Gimhae city. Analysis of soil showed high levels of Fe (470 mg/kg), Mn (80 mg/kg) and $NH_4$-N (15 mg/kg). Also, adsorption coefficient values (k and 1/n) were 0.00159 and 0.8714, respectively. This implies that the adsorption of the soil depends on organic matter. Water qualitiy of the river and the bank filtration revealed that the concentrations of TS and TDS almost didn't change but the concentration of SS decreased 84% through the bank filtration. $NH_4$-N in the bank filtration was detected more than 1 mg/L which might be due to agricultural activities in the research area. $NO_3$-N was close to the detection limit owing to the removal by the adsorption. $KMnO_4$ consumption and BOD of the river were decreased by the bank filtration 250% and 350%, respectively, while Fe and Mn were significantly increased by the bank filtration.

• Membrane and Water Treatment
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• 제1권1호
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• pp.61-74
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• 2010

This paper will integrate models at different levels (from filtration, backwashing to chemical cleaning and membrane lifetime) that can be used to minimize overall operating costs of a dead-end ultra filtration process that is used for the purification of surface water. Integration of the models leads to a multi-level optimization problem (at different levels different objectives should be reached). This problem is solved as a MINLP. Systematic modelling and optimization of membrane systems is not extensively discussed in the scientific literature. In this paper the first steps are taken in the formulation of proper models and the use of systems engineering tools to come to real optimal operating conditions. The optimized variables are used to calculate fouling profiles which can subsequently be used as inputs for a control system that actually enforces the profiles to a real pilot plant.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.447-450
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• 2004

This study was conducted to characterize groundwater and river-water fluctuations at a riverbank filtration site in Daesan-myeon adjacent to the Nakdong River, using time series analysis. Water levels from six observation wells from January 2003 to October 2003 were measured. The autocorrelation analysis indicates that the wells are divided into three groups: group 1 represents strong linearity and memory, group 2 intermediate linearity and memory, and group 3 weak linearity and memory. The analysis indicates that groundwater levels in different monitoring wells vary in response to river-water levels, groundwater withdrawal and seasonal rainfall. Cross-correlation was also divided into three groups. Group 1 shows the highest cross-correlation function (0.49 - 0.54) for a lag time of 0 hours, group 2 intermediate cross-correlation function (0.34 - 0.45), and group 3 the lowest cross-correlation function (0.23 - 0.25). Different cross-correlation functions among the 3 groups are interpreted as an effect of tile distance from the river to the pumping wells.

• 한국환경과학회지
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• 제26권10호
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• pp.1135-1146
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• 2017

At riverbank filtration sites, groundwater levels of alluvial aquifers near rivers are sensitive to variation in river discharge and pumping quantities. In this study, the groundwater level fluctuation, pumping quantity, and streamflow rate at the site of a riverbank filtration plant, which produces drinking water, in the lower Nakdong River basin, South Korea were interrelated. The relationship between drawdown ratio and river discharge was very strong with a correlation coefficient of 0.96, showing a greater drawdown ratio in the wet season than in the dry season. Autocorrelation and cross-correlation were carried out to characterize groundwater level fluctuation. Autoregressive model analysis of groundwater water level fluctuation led to efficient estimation and prediction of pumping for riverbank filtration in relation to river discharge rates, using simple inputs of river discharge and pumping data, without the need for numerical models that require data regarding several aquifer properties and hydrologic parameters.

• International Journal of Automotive Technology
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• 제8권2호
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• pp.165-177
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• 2007

Predictions of diesel particulate filtration are typically made by modeling of a particle collection, and providing particle trapping levels in terms of a pressure drop. In the present study, a series of single channel diesel particulate filter (DPF) experiments are conducted, the pressure traces are inversely analyzed and essential filtration parameters are deducted for model closure. A DPF filtration model is formulated with a non-linear description of soot cake regression. Dependence of soot cake porosity, packing density, permeability, and soot density in filter walls on convective-diffusive particle transportation is examined. Sensitivity analysis was conducted on model parameters, relevant to the mode of transition. Soot cake porosity and soot packing density show low degrees of dispersion with respect to the Peclet number and have asymptotes at 0.97 and $70\;kg/m^3$, respectively, at high Peclet number. Soot density in the filter wall, which is inversely proportional to filter wall Peclet number, controls the filtration mode transition but exerts no influence on termination pressure drop. The percolation constant greatly alters the extent of pressure drop, but is insensitive to volumetric flow rate or temperature of exhaust gas at fixed operation mode.

• Environmental Engineering Research
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• 제24권1호
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• pp.17-23
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• 2019

This study monitored changes in the level of heterotrophic bacteria in the filtrate and investigated the effect of stagnant water on it, using a batch-operated, gravity-driven membrane system for household water treatment. The filtration test was carried out in the presence and absence of stagnant water in the filtrate line. The results showed that stagnant water accelerated the heterotrophic bacteria levels, measured by heterotrophic plate count, even though the heterotrophic plate count of the filtrate finally increased up to $10^5CFU/mL$ regardless of the presence of stagnant water. When the change in heterotrophic plate count of a batch was monitored over filtration time, heterotrophic plate count of the filtrate rapidly decreased within 5 min for each batch filtration. Biofilm formation on the filtrate line was observed in the presence of stagnant water. The biofilm fully covered the filtrate line and contained numerous microorganisms. During storage after filtration, heterotrophic plate count increased exponentially. To improve the filtrate quality of a filtration-based household water treatment system, therefore, the stagnant water in the filtrate line should be minimized, the filtrate produced at the first 5 min is recommended not to be used as potable water, and the storage of filtrate should be avoided.

• 동의생리병리학회지
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• 제18권4호
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• pp.1207-1212
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• 2004

Twenty-one diabetic nephropathy patients with normal serum BUN(Blood Urea Nitrogen), creatinine levels and ten chronic renal failure patients with abnormal high BUN, creatinine levels were investigated to evaluate the renal function change after long term herb medicine administration. The hospitalized patients were administrated three times a day with herb medicine, which were prescribe frequently in practical oriental medicine such as many hospital and local clinics. Blood Urea Nitrogen, creatinine and glomerular filtration rate (GFR) were measured immediately after 7days medication. Serum BUN, creatinine levels in diabetic nephropathy patients changed from 17.63±4.38㎎/㎗, 1.09±0.26㎎/㎗(mean±SD) of pre-medication levels to 14.13±3.24 1,20±0.37, 14.75±2.21 1.23±0.55, 12.34±2.89 1.18±0.42 at 7th, 14th, 21th days after herb medicine administration respectively. Also 24hr urine total protein changed from 632.25±254.43㎎/㎗ of pre-medication levels to 623.18±231.56㎎/㎗ after herb medicine administration(P>0.05). Serum BUN, creatinine levels and GFR in chronic renal failure patients changed from 67.45±13.86㎎/㎗, 6.74±2.91㎎/㎗, 13.73±4.21㎖/min pre-medication levels to 61.23±17.75 6.43±2.29 15.49±3.56, 58.84±19.36 5.83±2.51 16.38±2.85, 56.39±20.33 5.64±2.52 16.73±3.40 at 7th, 14th, 21th days after herb medicine administration respectively. Therefore, there was not clinically remarkable difference in the serum BUN, creatinine, GFR levels between pre-medication and post-medication in both Group.

• International Journal of Vascular Biomedical Engineering
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• 제4권1호
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• pp.17-26
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• 2006

Diabetes mellitus (DM) is a metabolic disorder, characterized by varying or persistent hyperglycemia, which induces several changes in the erythrocyte membrane and its cytoplasm, leading to alteration in the deformability. Techniques applied to measure this are based on filtration of erythrocyte suspension through a membrane and to obtain diffraction pattern under sheared conditions. Ektacytometry requiring less quantity of blood with disposable flow chamber used to measure the deformability of erythrocytes obtained from patients with diabetes and also associated with nephropathy and retinopathy. A decreasing trend of deformability in these patients is observed. The shape parameter form factor, as determined by image processing procedure, increases with the increased of blood glucose levels and shows a pattern similar to filtration time of erythrocyte suspensions through cellulose membranes. Further work is suggested to detect micro-level changes in cell membrane in diabetic patients