• Proceedings of the Korean Society of Rheology Conference
• /
• 2001.09a
• /
• pp.159.5-159
• /
• 2001

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2004.11a
• /
• pp.233-237
• /
• 2004

• Journal of the Korean Geosynthetics Society
• /
• v.6 no.3
• /
• pp.25-30
• /
• 2007

The major reason to employ electrokinetic geosynthetics is to take advantage of its ability to densify very low permeability materials in shorter time periods than ordinary seepage consolidation. A number of laboratory scale experiments was carried out with acrylic column using natural clayey soil. The testing results indicate that (1) the electrically induced settlement was faster than the gravitational one, (2) the higher the voltage, the faster the dewatering but the less final settlement, and (3) the pH extended as low as 3 in the anode section and as high as 11 near the cathode.

• Environmental Engineering Research
• /
• v.20 no.1
• /
• pp.99-104
• /
• 2015

The purpose of this study is to evaluate the performance of forward osmosis (FO) system for harvesting microalgae cultivated in secondary sewage effluent. Microalgae species used in this study were chlorella sp. ADE4. The drawing agents used for forward osmosis system were seawater and concentrate of sea water reverse osmosis (SWRO) system. Chlorella sp. ADE4 cultured in secondary sewage effluent illustrated moderate efficiency in removal of total nitrogen (TN) (68%) and superior performance in total phosphorus (TP) removal (99%). Comparison of seawater and SWRO concentrate as drawing agent were made in FO membrane separation of the microalgae. The result from this study depicts that SWRO concentrate is strong drawing agent in FO membrane system providing an average dewatering rate of $4.8L/(m^2{\cdot}hr)$ compared to seawater with average dewatering of $2.9L/(m^2{\cdot}hr)$. Results obtained from this study indicated that FO system could be viable option for harvesting the microalgae for further biodiesel production. SWRO concentrate as a drawing agent could be very important finding in field of membrane technology for disposal of SWRO concentrate.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.1
• /
• pp.31-37
• /
• 2009

Low-pressure membrane processes have been extensively expanded their applications to drinking water production in a few decades. As a capacity of a membrane plant becomes greater in recent years, proper methods to increase water production as well as to treat residuals have drawn great attention. A possible treatment option for the better water production is to apply a dual membrane system. The second stage microfiltration was installed and operated for approximately six months. The residuals from the two stage microfiltration were investigated to learn their characteristics in settling and dewatering processes. The settlability of the membrane residuals were greatest at the SS concentration of approximately 15000mg/L. The proper dose of the polyelectrolytes for filterability were obtained in the range of 0.5~1%. In the dosage range, the water contents of the membrane residuals were greater but the SRF were lower than the residual from the conventional process.

• Journal of the Korean GEO-environmental Society
• /
• v.4 no.3
• /
• pp.61-67
• /
• 2003

A new precess which consists of pre-dewatering device, post composting for solid phase and post sequencing batch reactor(SBR) for liquid phase was designed. Nitrogen in supernatants of dewatering device was removed by sequencing batch reactor. Experiments were carried out to investigate the SBR operation modes such as fill ratio, SRT, and operation cycle. The optimum fill ratio, SRT and aeration/non-aeration time were 1/12, 15days, and 2hr aeration / 1hr non aeraion, respectively. Methanol as an external carbon source increased denitrification when step feeding method was applied, not single feeding method.

• Korean Journal of Food Science and Technology
• /
• v.28 no.4
• /
• pp.707-713
• /
• 1996

Changes of sodium chloride content in Chinese cabbage were investigated at different conditions. The diffusion rate of sodium chloride into the cabbage increased with increasing the temperature of brine solution. Sodium chloride content of Chinese cabbage at the lower portion of tank was higher than that at the upper position. The more washing and dewatering, the lower sodium chloride content of the cabbage was found. Microstructure pattern of salted cabbage tissue depended upon height of tank. The changed epidermis cell was recovered after several times of washing.

• Journal of the Korea Concrete Institute
• /
• v.13 no.4
• /
• pp.346-353
• /
• 2001

This research investigates the mixture proportioning of waste newsprint paper fiber for thin-cement product. Waste newsprint paper fibers obtained through shredded mechanically by a dry process. Waste newsprint paper fiber reinforced cement composites was manufacted by slurry-dewatering method. The waste newsprint paper fiber reinforcement conditions (fiber mass fraction, level of substitution of virgin fibers, level of fiber beating) and processing variables (pressed, unpressed) are optimized through experimental studies and statistical analyses based on factorial design of experiments and analyses of variance. The optimized recycled waste newsprint paper fiber reinforced cement composites were technically evaluated. The results are shown to possess acceptable properties and strong potentials of the recycling of waste newsprint paper of the reinforcement of thin-cement products.

• Food Engineering Progress
• /
• v.13 no.4
• /
• pp.251-261
• /
• 2009

In vitro physiological functions such as jack bean (Canavalia ensiformis) urease inhibitory activity and retarding effect of glucose/bile acid of Aloe vera gel concentrated by the optimized DIS (Dewatering Impregnation & Soaking) process conditions were examined. Urease inhibitory activity of DIS aloes ranged from 84.6 to 94.4%, which was similar to or higher than 86.3% of fresh aloe. Also, urease inhibitory activity of DIS aloes was maintained at initial levels after heat treatment (90$^{\circ}C$, 10 min.) and drying treatment (freeze or hot air drying). Urease inhibition pattern from Lineweaver-Burk plot indicated general non-competitive inhibition, and inhibition constants ($K_{IE}$ and $K_{IES}$) of DIS aloes were 41-149 and 87-163 $\mu$L/mL, respectively. DIS(glucose) and DIS(polyethylene glycol) exhibited the highest retarding effect of glucose and bile acid. Their retarding effects were about 1.6 and 1.8 folds higher than that of fresh aloe after 0.5 and 1 hr of the dialysis, respectively. Conclusively, the above in vitro physiological functions of Aloe vera gel concentrated by DIS process suggested that aloe products treated with DIS would have the potential benefits for protection against Helicobacter pylori and reduction of blood glucose and cholesterol levels.

• Geomechanics and Engineering
• /
• v.32 no.4
• /
• pp.387-396
• /
• 2023

Ground subsidence, which is a current concern that affects piled raft foundations, has occurred at a high rate in Ho Chi Minh City, Viet Nam, due primarily to groundwater pumping for water supply. In this study, the groundwater level (GWL) change affect on a piled raft foundation was investigated based on the three-dimensional finite element method (3D-FEM) using the PLAXIS 3D software. The GWL change due to global groundwater pumping and dewatering were simulated in PLAXIS 3D based on the GWL reduction and consolidation. Settlement and the pile axial force of the piled raft foundation in Ho Chi Minh subsoil were investigated based on the actual design and the proposed optimal case. The actual design used the piled foundation concept, while the optimal case applied a pile spacing of 6D using a piled raft concept to reduce the number of piles, with little increased settlement. The results indicated that the settlement increased with the GWL reduction, caused by groundwater pumping and dewatering. The subsidence started to affect the piled raft foundation 2.5 years after construction for the actual design and after 3.4 years for the optimal case due to global groundwater pumping. The pile's axial force, which was affected by negative skin friction, increased during that time.