• Journal of Ginseng Research
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• v.22 no.3
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• pp.211-215
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• 1998

A rapid separation of an edible panaxadiol (PD) and panaxatriol (PT) in ginseng saponins has been investigated by benzene ethylene resin adsorption method. Briefly, powdered red ginseng was extracted with water. The obtained ginseng extract were dissolved in suitable volume of distilled water, and adsorbed on the benzene ethylene resin with 200 folds water of the resin weight. Sugars and hydrophilic character compounds not absorbed were washed with water, and eliminated by 10-fold water of the resin weight. An edible panaxadiol and panaxatriol can be perfectly separated from ginseng saponins with the fractions below 40% aqueous ethanol and over 45% as an fluent.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1048-1050
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• 2008

Electric current flow was observed through imogolite film when imogolite ($(HO)_3Al_2O_3SiOH$) was exposed to water molecules and connected to external electrodes. Current flow was due to the bound water on the surface of imogolite. Current flow increased as the pH of the water decreased. The current-voltage (I-V) measurements from a field effective transistor (FET) using $H_2O$/imogolite film revealed that the current carrier in $H_2O$/ imogolite had p-type characteristics, i.e. the carrier was probably $H^+$. The possible mechanism for current transportation in imogolite/water was also suggested in this paper.

• Journal of Environmental Impact Assessment
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• v.14 no.1
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• pp.17-24
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• 2005

This study was performed to evaluate the adsorption rate of phosphate corrosion inhibitor and reaction rate constant in drinking water distribution systems. The optimum concentration of corrosion inhibitor would vary depending on the quality of water, pipe materials, and condition of metal surfaces. The current adsorption study indicated that the residual phosphate concentration of the corrosion inhibitor decreased with the time as it adsorbed on the surface of pipe material. As time went by, the residual phosphate concentration became constant. It means that the formation of the corrosion protection film on metal surfaces is completed.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.23-29
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• 2006

Biosorption technology was used to remove hazardous materials from wastewater, herbicide, heavy metals, and radioactive compounds, based on binding capacities of various biological materials. Biosorption process can be explained by two steps; the first step is that target contaminants is in contact with microorganisms and the second is that the adsorbed target contaminants is infiltrated with inner cell through metabolically mediated or physico-chemical pathways of uptake. Until recently, no information is available to explain the definitive mechanism of biosorption. The purpose of this study is to evaluate biosorption capabilities of organic matters using activated sludge and to investigate affecting factors upon biosorption. Over 49% of organic matter could be removed by positive biosorption reaction under anoxic condition within 10 minutes. The biosorption capacities were constant at around 50 mg-COD/mg-MLSS for all batch experiments. As starvation time increased under aerobic or anaerobic conditions, biosorption capacity increased since higher stressed microorganisms by starvation was more brisk. Starvation stress of microorganisms was higher at aerobic condition than anaerobic one. As temperature increased or easily biodegradable carbon sources were used, biosorption capacities increased. Consequently, biosorption can be estimated by biological -adsorbed capability of the bacterial cell-wall and we can achieve the cost-effective and non -residual denitrification with applying biosorption to the bio-reduction of nitrate.

• Clean Technology
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• v.27 no.1
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• pp.39-46
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• 2021

A road structure washing vehicle equipped with a 4 HP, 80 LPM ultrafine bubble generator was used to clean a tunnel wall and the surface of the surrounding structure, consisting of concrete and tiles, in a heavy traffic area around an apartment complex in the city. Ultrafine bubbles were generated by supplying air at 2 to 3 LPM and using a specially designed nozzle, whereas fine bubbles made by an impeller in a gas-liquid mixing self-priming pump were produced with an average diameter of 165.4 nm and 6.81 × 107 particles mL-1. Using a high pressure washer gun that can perform high-pressure cleaning at 150 bar and 30 LPM, ultrafine bubbles were used to wash dust adsorbed on the surface of the road structures. The experimental analysis was divided into before and after washing. The samples were analyzed by applying ISO 8502-3 to measure surface contamination of dust adsorbed on the surface. Using the transparent tape attached to the surface, the removal rate was calculated by measuring the weight of the dust, and the number of particles was calculated using the gravimetric method and the software, ImageJ. The results of the experiment showed that the number of dust particles adsorbed on the tile wall surface before and after washing were 3,063 ± 218 particles mL-1 and 20 ± 5 particles mL-1, respectively, with weights of 580 ± 82 mg and 13 ± 4 mg. Particles on the surface of the concrete structure before and after washing were 8,105 ± 1,738 particles mL-1 and 39 ± 6 particles mL-1, respectively, with weights of 1,448 ± 190 mg and 118 ± 32 mg.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.36-44
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• 1994

A study was carried out in order to investigate the removal efficiencies and removal characteristics of heaw metals such as Pb, Cd, Cr, Cu in raw water by one of conventional water treatment processes. The coagulants used in this study were Alum and PAC. Three kinds of water samples were provided: kaolin water, kaolin water mixed with humic acid and raw water from Han River mixed with suspended matter deposited on raw water inlet pipe. Heaw metals were added to the water samples with their respective turbidity, and jar tests were performed. In the results from heaw metal removal studies, lead might be adsorbed or exchanged on the particle surface (SS) rather than react with organic matter added. Cadmium was affected on the dissolved organic matter. Chromium was affected by the both dissolved organic matter and SS concentration, and the restabilization and the enmeshment appeared at moderate (50~80 NTU) and high (100 NTU) turbidity as defined in this experimenL The removal efficiency of copper was relatively little affected by the dissolved organic matter but by SS concentration in comparison with other heavy metals. In these studies as to the raw water turbidities and concentration of heaw metals, it is proved out that the removal efficiency on heaw metals in both cases of PAC and Alum as coagulants was not significantly different.

• Food Science and Preservation
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• v.24 no.4
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• pp.505-509
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• 2017

Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

• Geomechanics and Engineering
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• v.27 no.6
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• pp.573-582
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• 2021

From the effect of bound water, this study aims to seek the potential reasons for difference of mechanical experiment results of subgrades soils. To attain the comparatively test condition of bound water, dry forming (DF) and wet forming (WF) were used in the specimen forming process before testing, series of laboratory tests, i.e., CBR tests, direct shear tests and compaction tests. The measured optimal moisture contents, maximum dry densities, CBR, cohesion c, and internal friction angle 𝜑 were given contrastive analysis. Then to detect the adsorptive bound water in the subgrade soils, the thermal gravimetric and differential scanning calorimetry (TG-DSC) test were employed under different heating rates. The free water, loosely bound water and tightly bound water in soils were qualitatively and quantitatively analyzed. It was found that due to the different dehydration mechanics, the lost bound water in DF and WF process show their own characteristics. This may lead to the different mechanical properties of tested soils. The clayey particles have a great influence on the bound water adsorbed ability of subgrade soils. The more the clay content, the greater the difference of mechanical properties tested between the two forming methods. Moreover, in highway construction of southern China, the wet forming method is recommended for its higher authenticity in simulating the subgrade filed humidity.

• Membrane and Water Treatment
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• v.13 no.6
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• pp.313-320
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• 2022

Theoretical calculation results are presented for the enhancement of the water mass flow rate through the hydrophobic micro/nano pores in the membrane respectively on the micrometer and nanometer scales. The water-pore wall interfacial slippage is considered. When the pore diameter is critically low (less than 1.82nm), the water flow in the nanopore is non-continuum and described by the nanoscale flow equation; Otherwise, the water flow is essentially multiscale consisting of both the adsorbed boundary layer flow and the intermediate continuum water flow, and it is described by the multiscale flow equation. For no wall slippage, the calculated water flow rate through the pore is very close to the classical hydrodynamic theory calculation if the pore diameter (d) is larger than 1.0nm, however it is considerably smaller than the conventional calculation if d is less than 1.0nm because of the non-continuum effect of the water film. When the driving power loss on the pore is larger than the critical value, the wall slippage occurs, and it results in the different scales of the enhancement of the water flow rate through the pore which are strongly dependent on both the pore diameter and the driving power loss on the pore. Both the pressure drop and the critical power loss on the pore for starting the wall slippage are also strongly dependent on the pore diameter.

• Resources Recycling
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• v.7 no.1
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• pp.20-26
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• 1998

The mdy is to investigate the capanty and charactoristics of ammonia removal from waste water by artificial zeolite pellet which was synlhesized physicochemically using fly ash. A multi-stage adsorption method was adapted anrl the zeolile pellct as well as two types of natural zeolites are used for adsorption tests of ammonia io order to compare he adsorption capabilities with one anothcr. The expzrimmts was conducted into thrze stages, lhat is early, mddle and last according la the adsorbing stage and lhe number of column used. When camparing the removal efiicicncy in the final stage namral rcolites ratcd 64.5% and 78 5%, while zeohtc pdct rated 80.596, which showed larger amount of ammonia was adsorbed continuously than in other samples. Thc amount of adsorbed ammonia increased rs thc concenlraiion of ammonia increased and tl~e va~iation depending on the pH range showcd that larger amaunt of ammonia tended to be adsorbed m the neutral or akali pH range than in the acid pH range.