• Journal of the Korean Society of Tobacco Science
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• v.15 no.1
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• pp.90-97
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• 1993

1. Average moisture content of tobacco in BIB silo was about 19: 1% until 4hours conditioned time, and then moisture variation of tobacco after 2hr conditioned was very small. 2. Application of mathematical model for ordering system. 1) The constant K in the exponential equation varies inversely with both relative humidity and equilibrium moisture. 2) Time needed to order blending tobacco leaves with standard moisture from bulking and blending silo was 4 hours. 3) Reconstituted tobacco sheet had higher moisture absorption ratio than Oriental and Burley tobacco. 4) For minimize of conditioning time in BIB silo, the values of K and Mo given in this study can be used in equation(1) to calculate moisture absorption ratio and optimum conditioning time. 3. Average moisture content and water activity of conditioned tobacco for 4 hours in BIB silo was about 20% and 0.65. In this condition. microbial life will inhibite 4. Physical properties of conditioned tobacco in bulking and blending silo for 4hours was virtually no change.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.49-52
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• 2006

Epoxy resin has less reaction shrinkage, has better water proofing and thermal resistance than other repairing materials, to it has been applied broadly to repair and finish buildings and infrastructures. Although the ambient temperature constructed is varied with the seasons and epoxy resin has to mix with appropriate hardener due to the non self-hardening, as the real construction of it, the ambient temperature is ignored and the blending ration of epoxy resin and hardener is fixed. Also, because of the hardening time is aimed to temperature condition and the tolerance of blending ratio, we investigated the variation of viscosity according to ambient temperatures and hardener ratios. As a results of study, we can select the economical blending ratio of the epoxy resin and hardener according to site situation.

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.97-106
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• 1992

Apparent diffusion coefficients of Cl- ions through hardened cement pastes(HCP), which were partly subs¬tituted blast furnace slag, fly ash and silicafume for ordinary Portland cement, were determined. Also. Cl- and OW concentration of pore solutions which were extracted from HCP and the capacities of the HCP to bind CI were determined. Diffusion coefficients of Cl- ions through HCP were increased with water cement ratio(WfC), but decreased with addition of the blending materials. On the contrary, Cl- and OH concentration of the pore solutions were reduced by adding the blending materials.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.155-155
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• 2018

Uncertainty in flood forecasting using a coupled meteorological and hydrological model is arisen from various sources, especially the uncertainty comes from the inaccuracy of Quantitative Precipitation Forecasts (QPFs). In order to improve the capability of flood forecast, the uncertainty estimation and mitigation are required to perform. This study is conducted to investigate and reduce such uncertainty. First, ensemble QPFs are generated by using Monte - Carlo simulation, then each ensemble member is forced as input for a hydrological model to obtain ensemble streamflow prediction. Likelihood measures are evaluated to identify feasible member. These members are retained to define upper and lower limits of the uncertainty interval and assess the uncertainty. To mitigate the uncertainty for very short lead time, a blending method, which merges the ensemble QPFs with radar-based rainfall prediction considering both qualitative and quantitative skills, is proposed. Finally, blending bias ratios, which are estimated from previous time step, are used to update the members over total lead time. The proposed method is verified for the two flood events in 2013 and 2016 in the Yeonguol and Soyang watersheds that are located in the Han River basin, South Korea. The uncertainty in flood forecasting using a coupled Local Data Assimilation and Prediction System (LDAPS) and Sejong University Rainfall - Runoff (SURR) model is investigated and then mitigated by blending the generated ensemble LDAPS members with radar-based rainfall prediction that uses McGill algorithm for precipitation nowcasting by Lagrangian extrapolation (MAPLE). The results show that the uncertainty of flood forecasting using the coupled model increases when the lead time is longer. The mitigation method indicates its effectiveness for mitigating the uncertainty with the increases of the percentage of feasible member (POFM) and the ratio of the number of observations that fall into the uncertainty interval (p-factor).

• Membrane and Water Treatment
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• v.7 no.4
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• pp.355-365
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• 2016

The improvement of fouling resistance of porous polymeric membrane is one of the most important targets in membrane preparation for water purification in many process like wastewater treatment. Membranes can be modified by various techniques, including the treatment of polymer material, blending of hydrophilic polymer into polymer solution, and post treatment of fabricated membrane. This research proposed the modifications of morphology and surface property of hydrophobic membrane by blending polyethersulfone (PES) with three polymeric additives, polyvinylpyrrolidone (PVP), Pluronic F127 (Plu), and Tetronic 1307 (Tet). PES hollow fiber membranes were fabricated via dry-wet spinning process by using a spinneret with inner and outer diameter of 0.7 and 1.0 mm, respectively. The morphology changes of PES blend membrane by those additives, as well as the change of performance in ultrafiltration module were comparatively observed. The surface structure of membranes was characterized by atomic force microscopy and Fourier transform infra red spectroscopy. The cross section morphology of PES blend hollow fiber membranes was investigated by scanning electron microscopy. The results showed that all polymeric additives blended in this system affected to improve the performances of PES membrane. The ultra-filtration experiment confirmed that PES-PVP membrane showed the best performance among the three membranes on the basis of filtration stability.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.217-221
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• 2012

Blending films having enhanced water-resistance and barrier properties were prepared using the mixtures of poly(vinyl alcohol) (PVA) aqueous solution and poly(ethylene-co-acrylic acid) (EAA) dispersed in water. Thermal-mechanical properties, contact angles, water-vapor transmission rates (WVTR) and oxygen transmission rates $(O_2TR)$ were measured with the content of EAA of blending films, and their water-resistance was evaluated. The tensile strength of the films was found to be $9.16{\sim}11.75\;kg/mm^2$ which showed no significant difference compared with that of PVA, and the hardness increased with the content of EAA. The glass transition temperature and melting temperature of the blending films were slightly improved. The film prepared with PVA/EAA (= 90/10), of which the swelling and solubility were measured to be 109 and 0%, respectively, showed improved water-resistance. The WVTR and $O_2TR$ for the PET film (thickness $50\;{\mu}m$) coated with PVA/EAA (= 90/10) film (thickness $2.5\;{\mu}m$) were measured to be $9.1\;g/m^2/day$ and $2.0\;cc/m^2/day$, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.8-16
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• 2001

To manufacture toilet tissue with ONP (old newspaper), the effect of fractionation fiber (R150, R100, R70 mesh) and bleaching(P, PY), blending (70/30) with MOW(mixed office wastepaper) or WL(white ledger) and the addition of softener on the optical and mechanical properties were studied. Considering the pulp yield, brightness and strengths, fibers of R100 mesh fraction were proper to be produced to toilet paper from ONP. This pulp showed the pulp yield of 76.8%, brightness of 50.2% ISO and tensile index of 21.1 Nm/g. By the bleach with P and PY stages, the brightness of the pulps increased up to 60.3% ISO and 61.8% ISO, respectively. When blended with MOW (57.3% ISO) or WL (76.2% ISO), the brightness of the former increased up to 58.5% ISO, the latter up to 63.6% ISO. The strengths of pulp blended with WL were higher than those of fractionated pulp from 100% ONP, however there was no difference in strengths between fractionated pulp and blended pulp wth MOW. While the addition of softener improved the softness of paper, but it decreased strengths of pulp and extended dispersing time in water.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.1
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• pp.33-40
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• 2005

This study was carried out for effective utilization of recycling resources to investigate the repulping conditions of car air filter waste paper and to evaluate the application into corrugating medium papermaking by blending these repulped pulps. Car air filter waste paper was made of virgin BKP and it was dipped into phenol resin solution. It was well disintegrated by laboratory Valley beater with 10%(basis on oven-dried pulp weight) NaOH addition and defoamer usage. The optimal temperature, beating consistency and treatment time were mainly $40^{\circ}C$, 1% and $30{\sim}40$ minutes, respectively. Handsheets were prepared with various blending ratios between air filter recycled pulp and KOCC. In the case of $10{\sim}20%$ substitution with air filter recycled pulp, physical properties reductions as compressive strength and burst strength of sheets were lower than others. These results showed more favour than the partial substitution of KOCC for corrugating medium even though some strength reduction of paper. It was also observed that the waste water of air filter recycling was not affective to environmental problems.

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.312-317
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• 1985

This study was attempted to investigate the occurrence and the characteristics of ascorbic oxidase in cucumbers. Ascorbic acid oxidase was isolated from cucumbers and concentrated using ammonium sulfate precipitation. The results of this study are as follows ; 1) Ascorbic acid oxidase activity was detected in whole cucumber homogenate. 2) Highest amounts of ascorbic acid destroyed after 10 minutes' incubation of ascorbic acid oxidase with its substrate. 3) The optimum pH and temperature of this enzyme were found to be pH 6.5 and $40^{\circ}C$, respectively. 4) Ascorbic acid content in cucumber juice prepared using the cold water $(4^{\circ}C)$ was higher than that made with water at $30^{\circ}C$. 5) When orange juice ( pH 3.4 )was added, ascorbic acid destruction was completely ceased. (The ascorbic acid oxidase was inactivated at pH 3.9) Decreasing the temperature and pH are recommended to achieve maximum stability of ascorbic acid in preparing cucumber juice.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.221-233
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• 2018

Recently, the flood damage by the localized heavy rainfall and typhoon have been frequently occurred due to the climate change. Accurate rainfall forecasting and flood runoff estimates are needed to reduce such damages. However, the uncertainties are involved in guage rainfall, radar rainfall, and the estimated runoff hydrograph from rainfall-runoff models. Therefore, the purpose of this study is to identify the uncertainty of rainfall by generating a probabilistic radar rainfall ensemble and confirm the uncertainties of hydrological models through the analysis of the simulated runoffs from the models. The blending technique is used to estimate a single integrated or an optimal runoff hydrograph by the simulated runoffs from multi rainfall-runoff models. The radar ensemble is underestimated due to the influence of rainfall intensity and topography and the uncertainty of the rainfall ensemble is large. From the study, it will be helpful to estimate and predict the accurate runoff to prepare for the disaster caused by heavy rainfall.