• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.159-166
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• 2014

In recent years, researchers have put a considerable effort to decrease the emission of harmful gaseous pollutants to the atmosphere. In order to remove simultaneously $SO_2$ and $NO_X$ from the flue gas of small and medium-sized ship, we designed minimal wet scrubber inside a compact multistage modular system. In this study we proceed experiment of elemental technology at each stage of the scrubber. The each stage is oxidation of NO which is the main component of $NO_X$, and removal of $SO_2$, respectively. $NaClO_2$ was used to oxidize NO gas, and NaOH was used to remove $SO_2$ gas. The maximum NO conversion efficiency and the $SO_2$ removal efficiency are both indicate 100%.

• KSBB Journal
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• v.30 no.6
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• pp.332-338
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• 2015

The objective of this study was designed to determine the possibility of bioethanol production from wasted medium density fiberboard (wMDF). We were investigated the enzymatic saccharification characteristics using the enzyme (Cellic CTec3) after pretreatment with sodium chlorite. According to the component analysis results, the lignin contents before and after the pretreatment of wMDF (milling using sieve size of $1,000{\mu}m$) was significantly reduced from 31.13% to 4.11%. Therefore, delignification ratio of pretreated wMDF was found to be up to about 87-89% depending on the sieve size. And we were tested to compare the saccharification ratio according to the sieve size of wMDF ($1,000{\mu}m$, $200{\mu}m$), but it was no significance depending on the sieve size. When enzyme dosage was 5% based on the substrate concentration, enzymatic saccharification ratio was obtained up to 70% by maintaining at $50^{\circ}C$ for 72 hours. We could made the substrate concentration of pretreated wMDF ($1,000{\mu}m$) up to 12% and then enzymatic saccharification ratio was 76.8%, also contents of glucose and xylose were analyzed to 77,750 and 14,637 mg/L, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1286-1296
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• 2007

Hanji, the korean traditional papers were mostly made from mulberry paper. But the production and demand of hanji have decreased rapidly because mulberry paper yields were insufficient and handworked hanji procedures were complicated. Recently, the researches on hanji were carried out to improve the properties of hanji. Kenaf fibers have been interested as a substitute resource of mulberry paper for hanji production. In this research, Kenai pulps were manufactured with removal methods of lignin or hemicellulose from kenaf fibers and paper mulberry pulps with traditional alkali methods. Kenaf papers, paper mulberry, and kenaf/paper mulberry mixed papers were manufactured with their pulps. The crystallinity, fiber length, color of the pulps and tensile strength, tear strength, water absorption of the papers were investigated. The results were as follow: The removal rates of lignin of chemical retted kenaf fibers with sodium chlorite reaction for 40 minutes were 70% and were higher than 40% of double retted fibers. Paper mulberry pulps has less lignin and hemicellulose than kenaf differently. The crystallinity of paper mulberry pulps were very low with 60%, but kenaf pulps were 90%. The chemical retted CR-40-1 pulps were similar with paper mulberry pulps on fiber length & fibrilation of fibers. Tensile strength of paper mulberry were higher than kenaf papers because of fibrilation of paper mulberry, but tear strength were lower. Tensile strength and tear strength were improved on kenaf/paper mulberry 30/70 mixed papers.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.17-24
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• 2015

In this study, the effect of delignification degree of Korean white pine wood on fibrillation efficiency by wet disk-milling (WDM) and the properties of thus-obtained microfibrillated cellulose (MFC) were investigated. The effect on the tensile properties of nanopaper was also investigated. The delignification degree was adjusted by repeating 'Wise' method using sodium chlorite and acetic acid. The increase in delignification degree improved fibrillation efficiency, showing the smaller nanofiber dimension at the shorter WDM time. The filtration time of MFC water suspension was increased by the increase of WDM cycles. Tensile strength and elastic modulus of the nanopaper were increased by increasing delignification degree and disk-milling cycles.

• Journal of Plant Biology
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• v.30 no.2
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• pp.135-149
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• 1987

An experiment was made in order to analyze the growth characteristics and productivity of Zoysia japonica under control, mowing and TIBA treatment conditions at the experimental farm of Kyung Hee University. The field was planned by the split plot design method and each treatment was given to two plots (40$\times$40 and 100$\times$100 mm) and was replicated three times. Each plot was 9$m^2$ for Zoysia japonica. The sampling of each plot was taken once a week after sowing. In order to know the dry matter of total standing crops, each organ of plants was kept at 9$0^{\circ}C$ and weighed. Total leaf area of a plant was measured by drawing method. The author adopted the growth analysis of English School. Holocellulose analysis by sodium chlorite method was made. The increasing rate of LAI was high in all plots between 10th and 12th week after sowing and high growth rate of assimilatory organ was observed in low density area of TIBA plot. Between 10th and 12th week after sowing all the experimental plots showed high increasing rate of standing crop and in the process of growth each density area of TIBA plot recorded high increasing rate. In all the plots F/C ratio and RGR were high when the growth rate of assimilatory organ was increasing cosiderably, and the higher the planting density was, the higher F/C ratio was recorded. In all the plots NAR recorded maximum rate before the growth period to show a high increase of RGR. In the process of the growth TIBA plot showed high icnreasing rate of NAR. CGR showed high value in high density areas of all the plots and reached its maximum in the 13th week after sowing. Compared to the other experimental areas the low planting density areas of control plot and TIBA plot showed considerable earlier lignification indicating low Holocellulose content in the growth process.

• Journal of Industrial Technology
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• v.9
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• pp.29-41
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• 1989

A general study on the upgrading of mica minerals which are mainly found in pegmatite deposits was carried out for the purpose of developing a technique for recovering mica in form of comercial grade products. By the way the grade one of about 5~6% $K_2O$ still is not developed. The target of this research work is to be establish a process for the efficient concentration of muscovite, containing more than 10% $K_2O$. The tests are applied to incraese the recovery and grade of concentrates in term of variations of conditions. The test sample consists of mainly muscovite and gangue mineral such as quartz, pyrite and chlorite. Decantation and shaking table tests were ineffective to up-grade this low grade one, but flotation method gave satisfactory result. By means of grade one, but flotation method gave satisfactory result. By means of grindability tests, an optimum result could be obtained from the sample ground to -48mesh feed size. The flotation result indicates that the dodecyl ammonium chloride used as a cationic collector is effective on the negatively charged surface, while the sodium dodecyl sulfate as an anionic collector is effective on the positively charged surface. Muscovite was floated by petroleum sulfonate as well as amine type collector, it also floated by MIBC as well as pine oil frother under well condition. Fine muscovite concentrates of about 10.68% $K_2O$ was obtained with 22.4% yield, by decantation, the muscovite concentrates of 10.10% $K_2O$ was obtained with 23.54% yield, by table concentration, the muscovite concentrates of 11.51% $K_2O$ was obtained with 23.0% yield by flotation.

• KSBB Journal
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• v.31 no.1
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• pp.73-78
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• 2016

The aim of this study attempted to verify the possibility of bioethanol production using wasted medium density fiberboard (wMDF). In order to produce bioethanol from wood cellulosic materials must be carried out the process of pretreatment, saccharification, fermentation and distillation. First, the wMDF was pretreated using sodium chlorite and pretreated wMDF was prepared to 8% slurry and then slurry was saccharified with the commercial enzyme (Cellic CTec3). The fermentable sugar and pH of saccharified substrate were about 5.5% glucose and 4.4, respectively. Herein we compared the results of ethanol yield according to the nutrients added or without addition to increase ethanol yield. Ethanol fermentation was finished in about 24 hours, but it was delayed in experimental group without nutrients. Ethanol content and fermentation ratio of the final fermented mash prepared by utilizing jar fermenter was 25.40 g/L and 86.64%, respectively. At this time, the maximum ethanol productivity was confirmed as 1.78 g/Lh (ethanol content 21.38 g/L, 12 h), and the overall ethanol productivity was 1.05 g/Lh (ethanol content 25.27 g/L, 24 h). Using fermented liquid we could produced bioethanol 95.37% by continuous distillator packed with copper element in laboratory scale. These results show that wMDF has a potential valuable for bioethanol production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1158-1167
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• 2012

During the peeling, cutting, and shredding of wild root vegetables, the surface is exposed to air. This results in a rapid deterioration in quality and an increase in the potential of contamination by microorganisms, both of which reduce the shelf-life of wild root vegetables in retail markets. Thus, in this study, the effects of various washing treatments on the quality of wild root vegetables, including lotus root, burdock root, and bellflower root, were investigated at 10 and $24^{\circ}C$. Lotus root, burdock root and bellflower root were washed with 0.2% acetic acid (AA), 0.2% citric acid (CA), 500 ppm acidified sodium chlorite (ASC), and tap water (TW), which was used as a control, and stored at $10^{\circ}C$ and $24^{\circ}C$. The changes in total plate counts, coliform groups, polyphenol oxidase (PPO) activity, color, pH, and exterior appearance of the samples were then evaluated. The pH and initial microbial contamination levels were reduced when the root vegetables were washed with AA, CA, and ASC. In particular, initial population levels of total plate counts and coliform groups were not detected in lotus root and burdock root that had been washed with ASC and their growth was significantly (p<0.05) inhibited during storage at 10 and $24^{\circ}C$ when compared to the control (TW). In addition, the polyphenol oxidase (PPO) activities of the root vegetables washed with AA, CA and ASC were lower than that of root vegetables washed with TW. ASC was determined to be the most effective treatment for preventing microbial growth, tissue softening, and the development of browning and an unpleasant smell. At $10^{\circ}C$, the overall qualities of the wild root vegetables were maintained longer when compared to $24^{\circ}C$.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.988-993
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• 2008

The characteristics of NO oxidation using sodium chlorite ($NaClO_2$) powder have been investigated by a flow type packed-bed reactor, where the reaction temperature and the space velocity are varied in the range of $20{\sim}230^{\circ}C$ and $0.4-2.2{\times}10^5hr^{-1}$, respectively, and the simulation gas mixtures are composed of NO (0~200 ppm), $NO_2$ (0-200 ppm), $O_2$ (0~15%) and $H_2O$ (0~15%) within $N_2$ balance. It has been found that the oxidation efficiency of NO depends greatly on the reaction temperature, exhibiting the existence of critical reaction temperature at about $170^{\circ}C$ where the oxidation efficiency of NO is maximized and then abruptly decreased with further increase of reaction temperature, resulting in being negligible over $190^{\circ}C$. Such a behavior in the oxidation efficiency has been originated from the phase transition of $NaClO_2$ at about $170^{\circ}C$ to form $NaClO_3$, and NaCl which are chemically inactive toward the oxidation of NO. The chemical reaction of NO with $NaClO_2$ has been observed to produce $NO_2$, ClNO and $ClNO_2$, whereas that of $NO_2$ only OClO species. Additionally, we have also observed that the introduction of $O_2$ and $H_2O$ has little influence on the oxidation of NO.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.34-41
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• 2000

Recently many scientists have tried to synthesize biodegradable polymers due to durable and non-biodegradable products of conventional synthetic plastics when these were wasted in nature. So to reuse the wastepapers for biodegradable polymer resources, ONP (old newsprint), OCC (old corrugated containerbpard) were carried out by the pretreatment of chlorinite, hypochlorite and oxygen-alkali treatment conditions. For manufacturing of biodegradable polymer with wastepaper, this study performed to investigate change of chemical components and optimal pretreatment condition. The summarized results in this study were as follows: Lignin content in ONP and OCC was was higher than in MOW and ash content was the highest in MOW. More amount of ash components were reduced by wet defiberation than by dry defiberation. Wet defiberation fiber are better than dry defiberated fiber in chemical pretreatment condition for wastepapers, and the best result was obtained in the condition of sodium chlorite at $70^{\circ}C$, because it has high delignification ratio, ${\alpha}$-cellulose contents and degree of polymerization in this treatment condition. Oxygen-alkali treatment condition is the worst method because of low yield, low degree of polymerization in this pretreatments.