• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1082-1087
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• 2006

BAC backwashing process in ozone-BAC advanced water treatment process was experimentally studied. The operation and performance of backwashing were evaluated by measuring the effects of water temperature and water input rate on the backwashing interval and duration, and also the change of the amounts of biofilm and HPC in treated water before and after backwashing. The experiments were carried out with the pilot scale test module built in a existing water treatment plant, and the following results were obtained. Longer backwashing time than that of design operating condition was needed for satisfying the suitable turbidity of washing water effluent. Depending on water temperature, 7 days of backwashing cycle was recommended for the period lower than $15^{\circ}C$, and 10 days for the period higher than $15^{\circ}C$. After backwashing, the amounts of biofilm and HPC decreased to 1/10 and 80%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.999-1005
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• 2015

Bacillus-based feed additive was evaluated for its efficacy on growth performance, nutrient digestibility, fecal gas emission, and the consumption of time and amount of water for cleaning the pen of growing finishing pigs. A total of 120 growing pigs ($23.59{\pm}1.41kg$) were used in a 16-wk feeding trial. Pigs were randomly distributed into 1 of 2 treatments on the basis of body weight and sex. There were 12 replicate pens per treatment, with 5 pigs (3 barrows and 2 gilts) per pen. Dietary treatments were CON which was basal diet, and T1 which was CON+62.5 ppm microbial feed additive that provided $1.47{\times}10^8cfu$ of Bacillus organisms per gram of supplement. During the weeks 0 to 6, average daily gain (ADG) in T1 treatment was higher (p<0.05) than CON, but no improvement in average daily feed intake (ADFI) and feed efficiency (G:F) was noted. During 6 to 16 weeks, no difference (p>0.05) was noted in growth performance. However, ADG was improved (p<0.05) and overall ADFI tended (p = 0.06) to improve in T1 compared with CON. At week 6, the co-efficient of apparent total tract digestibility (CATTD) of dry matter (DM) nitrogen (N) was increased (p<0.05) in T1 compared with CON. Fecal $NH_3$ emission was decreased (p<0.05) in T1 compared with CON, at the end of 6th and 15th weeks. The time and water consumed for washing the pens were decreased (p<0.05) in T1 compared with CON. In conclusion, supplementation with Bacillus-based feed additive could improve the overall growth performances, increase the CATTD of DM and decrease the fecal $NH_3$ content and the time and water consumed in washing the pens for growing-finishing pigs.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.374-379
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• 2016

When using an ionic liquid as co-solvent, the extraction efficiency of anticancer agent paclitaxel from biomass was dramatically improved. However, the residual ionic liquid had a significant negative effect on convenient and feasibility of following concentration and drying steps. In this study, a novel method was developed for the effective drying of the crude extract obtained from biomass extraction with ionic liquid. The residual ionic liquid was easily and conveniently removed by drying alone after pre-treatment and additional washing of a sample with water. The optimal crude extract/water ratio and mixing time for pre-treatment and crude extract/water ratio for additional washing were 1:70 (w/v), 4 min, and 1:100 (w/v), respectively. In the microwave-assisted drying process, the drying time was 9-fold shorter than in the vacuum oven drying process.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.70-78
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• 1988

To separate and utilize the main components of hardwood (Quercus mongolica) by organosov pulping (ester pulping), chips were cooked at various conditions such as; the solvent ratio (acetic acid: ethylacetate: water, 50:25:25; 33:33:34; 25:50:25), maximum temperature (165, 170, $175^{\circ}C$), and cooking times (2, 2.5, 3 hr). The pulps were bleached by the sequences of CEDED, C/DEDED, PEDED. Lignin, sugars, and acetic acid were separated from black liquor and washing liquors. 1. The selective delignification at optimal pulp yield (43-45%) was obtained by cooking at acetic acid: ethylace tate: water ratio of 33:34:34 for 3 hr at $170^{\circ}C$. But in this case, kappa no. of the pulp was not reduced under 60 points. 2. Kappa no. of the pulp could be dropped by an acetone wash to remove reprecipitated lignin a t cooked pulp. 3. The unbleached pulps had a brightness of 45-50%, whereas the bleached pulps gave at 88-93% brightness. Tensile, burst, and tear strengths of the bleached pulps were lower than those of kraft pulp, especially in tear strength. The pulps which were bleached with CEDED sequence were higher in strengths than another bleaching sequences. 4. Lignin of 90-95%(lignin base on wood)was separated from black liquor and washing liquors, while the purified sugars and recovery of acetic acid were a low. An organic phase composed of acetic acid, ethylacetate, and water was separated to a two-phase system by proper adjustment of the solvent ratios.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.282-287
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• 2009

As current international guideline and IMO regulation give severe restrictions for ships to manage ballast water to reduce unintentional organism transfers, several ballast water treatment systems recently have been being developed together with filtration. That is because discharging ballast water from ships causes many pollutions by foreign biological invasive species. The primary treatment system being considered in this study was based on fine screen filtration technology applied to ballast water filter in ballast tank in order to reduce the load of ballast water treatment system. New ballast water filtration system was invented and analysed. The structural stress and strain analysis for ballast filtration systems which are current and invented filters were carried out using UGS and Ansys. The results showed that the structure of current filtering module was not designed to meet the requirement of sea water filtration during ballasting operation. The studies also showed that the invented design of filtration system equipped with back washing and automatic scrapper for eliminating cake of bio-species might be a potentially effective technology for ballast water management of ship's ballast tank.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.441-444
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• 2006

A lot of water is using in the paper mill for dilution, washing, sealing, and other process operation. As the regulation of water environment has been more tightened than ever before, water management in the paper mill becomes the most important task. Topics on reducing fresh water and increasing recycling water have been studied. Further, an interest in zero-effluent system has been increased. The pH of waste water in paper mill is usually weak acidic or neutral. The waste water in the paper mill includes water insoluble organic materials that are not easy to be dissolved in the water, inorganic materials that never react with water and chemical additives that are used to recycled fiber. This study investigated on the effect of various materials used in paper mill on COD. This data could be used to control the environmental load in paper mill. COD caused by raw materials and NBDCOD (Non Bio Degradable COD) after the activated sludge process are investigated in this study. Results obtained in this study can be used in a simulation program designed to control environmental load in the paper mill.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.95-100
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• 2009

The water purification systems have been hardly used for agricultural purpose due to their complicated compositions and high costs for farmers, while only simple filtrations have been applied to irrigation systems in order to prevent the system from clogging problems. This study therefore developed a clean water supplying system, the Filter-Disinfection-Adsorption (FDA) system, especially for greenhouse cultivation of where low quality of water is available. This system has also been produced for providing convenience water to farmers in the areas of no water supply service systems for the purpose of washing their bodies or agricultural machineries after farm work. The FDA system consists of three stages of purification processes with an integral module, including disk and teflon filtrations and Ultraviolet (UV) sterilization processes. Indoor experiments were undertaken with a trial product of the FDA system to test its performance. The operation test of the process was performed as well as the condition check of each item including UV module, filters, control panel, pump, valves, etc. The results shows good performance of each test with no critical problems. The initial and maintenance costs were also analysed with other purification systems. From the comparisons, the FDA system found to be very economical and easy to use.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1438-1441
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• 2008

Throughout the history, the people of Iran have battled the dryness by innovations to preserve every drop of water that lands from the rare clouds, or from a stream flowing out of distant springs. Water is precious and held with highest respect, whether stored for drinking at an Ab-Anbar, or for washing and farming at the Houz in the middle of their oasis homes and orchards, or sourced at a Qanat spring or Jooy under ground. How it is that drinking water as cold as a mountain fall is found in desert of Iran? Ab-Anbar is an ancient means of water preservation and cooling through anunderground building structure. These underground structures have been present in Khorasan and other desert provinces of Iran as public or private water storage facilities, widely used before the installation of public plumbing systems in the late 1950s. Although many of these structures are still functional, most have been protected by government for restoration or viewing by the public as historical heritage. Khorasan natural dry climate and the massive surrounding deserts have been a breeding ground for many designs of Ab-Anbars. Today the existing number of such facilities stands in the province of Khorasan. Usually these structures were built in populated areas, also there are some forms of such structures on old trade routes and roadways leading to and from populated towns. This paper considers the history of Ab-Anbars in Khorasan as well as other relevant aspects such as types, components, construction methods and materials, filling and withdrawal systems.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.51-58
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• 1995

To prepare a durable softening water repellent, quaternized octadecyl methacrylate-2-diethyl-aminoethyl methacrylate as a mother resin and quaternized 1, 3-dioctadecyl-2, 7-dioxy-6, 8-di(2-hydroxyethyl)-1, 3, 6, 8-tetraazacyclodecane which increase the softening effect and the hydrostatic pressure blended with waxes and their emulsifier in various proportions to give water repellent PADWC. As the results of the measurement of water repellency, washable, tear strength and crease recovery to polyestercotton(P/C) blended fabrics treated with PADWC only or addition of textile finishing resin, the physical properties were increased. There was no significant lowering effect in water repellency when PADWC was treated the antistatic agent by the one-bath method, and the effect of water repellency by the adding the catalyst was studied. PADWC was confirmed as durable water repellent with the results of making little difference of water repellency as ${\pm}5$ point after and before washing.

• Membrane Journal
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• v.27 no.1
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• pp.68-76
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• 2017

Flat membrane with $0.4{\mu}m$ pore size was prepared with PVdF (polyvinylidene fluoride) nanofiber, which has the advantages such as excellent strength, chemical resistance, non-toxicity, and incombustibility. The spiral wound module was manufactured with the flat membrane and a woven paper. Hybrid water treatment process was composed of the PVdF nanofibers spiral wound microfiltration and granular activated carbon (GAC) adsorption column. Effect of GAC packing mass was investigated by comparing the case of recycling or discharging the treated water using the synthetic solution of kaolin and humic acid. After each filtration experiment, water back-washing was performed, and recovery rate and filtration resistances were calculated. Also, effect of GAC adsorption was compared by measuring turbidity and $UV_{254}$ absorbance. As a result, there was no effect of GAC packing mass on turbidity treatment rate; however, the treatment rate of $UV_{254}$ absorbance was 0.7~3.6% for recycling the treated water, and increased to 3.2-5.7% for discharging the treated water. In the case of recycling the treated water, reversible filtration resistance ($R_r$) and irreversible filtration resistance ($R_{ir}$) trended to decrease as increasing GAC packing mass; however, total fitration resistance ($R_t$) was almost constant, and recovery rate of water back-washing trended to increase a little.