• Korean journal of food and cookery science
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• v.28 no.6
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• pp.711-719
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• 2012

The collagens from squid (Todarodes pacificus) skin and Alaska pollack (Theragra chalcogramma) skin were extracted and their physicochemical properties were investigated. The yield was improved with the increase of NaOH concentration and was increased Neutrase than Alcalase in enzymatic hydrolysates. Protein and collagen contents from Alaska pollack skin were 38.3~62.7% and 13.1~28.9%, respectively. All enzymatic hydrolysates also showed high antioxidant activities as NaOH concentration decrease. Composition of their amino acids was mainly glycine and proline. The spectrum of FT-IR of the collagen showed wavenumber at $1,631cm^{-1}$, $1,549cm^{-1}$, $1,234cm^{-1}$ and $3,322cm^{-1}$ representing the regions of amide I, amide II, amide III and amide A, respectively. The decomposition temperature for the collagen was in the range of $300^{\circ}C$ and showed relatively good enough for their thermal stabilities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.690-695
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• 2016

This study was performed to evaluate the effect of alkaline treatment on Styela clava tunic (SCT). Considerable damage to the surface of alkali-treated SCT was observed by scanning electron microscopy (SEM) in a concentration-dependent manner upon alkaline treatment. The amount of crystalline region in SCT gradually increased with increasing NaOH concentration, which was analyzed by X-ray diffraction and thermogravimetric analysis. The initial enzymatic reaction of Celluclast toward SCT was elevated by treatment with NaOH up to 1.0 N concentration due to disruption of the SCT surface by promoting binding of enzymes with SCT. However, in the late stage of the enzyme reaction, hydrolysis rate decreased with elevation of NaOH concentration, thereby increasing the amount of non-reacted residuals. This result was due to the increase in the crystalline regions in SCT.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.88-94
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• 2010

Cattail (Typha L.) was used as a raw material for producing both bio-ethanol and pulp for papermaking at the same time. Pretreatments of cattail stems and leaves with acid ($H_2SO_4$) and alkali (NaOH) in three different addition levels were studied before soda pulping. The acid pretreatment gave reducing sugar of 15.2% of initial weight, but alkali pretreatment close to 1%. Soda pulping of the pretreated cattail gave 3% reduction in pulp yield and less bonding properties in paper; however, refining of the pulp from the pretreated cattail with alkali restored their fiber bondings up to that of the pulp from no-pretreated cattail at equivalent freeness.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.811-812
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• 2023

드럼 연습 및 연주를 쉽게 배우고 즐기기 위한 시각적 가이드를 제공한다. CNN과 OpenCV를 활용하여 악보의 음표 이미지를 처리하고, 데이터 수집, 전처리, 모델 학습, 서버와 안드로이드 애플리케이션 연동 등 다양한 과정으로 구현된다. '드럼라이트'는 드럼 연주의 접근성을 높이고, 다른 악기와 음악 학습 분야에도 확장 가능한 가능성을 제시한다.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.368-374
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• 1984

The purification of 5'-riboncleotide using ion exchange resins has been studied and the optimum conditions were determined. The amount used of Amberlite IR120 ion exchange resin in 2nd resin tower could be reduced up to 20% by pretreating the hydrolyzed RNA solution in 1st resin tower. The amount used of regenerant could be also reduced up to 20% by desalting the hydrolyzed RNA solution in the 1st tower, because the desalted solution eluted easily by the water in the 2nd tower. The crystal obtained in this experiment was the mixed-crystals of $5'-IMP.Na_2\;and\;5'-GMP.Na_2$. The crystallization of the complexes formed from $5'-IMP.Na_2\;and\;5'-GMP.Na_2$ gave the best result at pH 7.6. The yield of crystal complexes formed from $5'-IMP.Na_2\;and\;5'-GMP.Na_2$ was obtained higher in high MeOH concentration. However, in higher than 60% MeOH concentration the products was amorphous. The higher content of MeOH for the crystallization of the product gave the smaller value of $5'-IMP.Na_{2}/5'-GMP.Na_2$.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.67-78
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• 2001

Two species(Quercus mongolica, populus euramericana) of hardwood chips were subjected to steam explosion 25 kg/$cm^2$, for 6 min. The exploded woods were treated by the single or multi-stage chemical process with sodium hydroxide, sodium hypochlorite and sodium chlorite. The multi-stage treatment of exploded wood can be successfully removed lignin. Enzymatic hydrolysis rate of substrate varied from 25% for exploded wood to about 80% for the multi-chemical treated exploded wood. The enzymatic susceptibility was different among wood species. The multi chemical treatment of the exploded wood resulted in the high rate of glucose in the enzymatic hydrolyzate. Cellulase adsorption increased at high lignin content of substrates, while crystallinity, pore area and specific surface area of substrates did not affected enzyme adsorption. According to the proposed pretreatment and saccharification process in this study, it can be acquired about 37~40 kg of glucose from 100 kg of hardwood.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.27-39
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• 2019

In this study, thermal-alkali pre-treatment (THAP) optimal condition and co-digestion efficiency with THAP of the mixture food waste and sewage sludge were evaluated for improving the performances of co-digestion for mixed food waste and sewage sludge. The optimal condition of THAP was evaluated for solubilization COD, CST(Capillary Suction Time), TTF(Time to Filter), and volatile fatty acids (VFAs) with THAP temperature and NaOH concentration. In addition, the co-digestion of mixed food waste and sewage sludge were evaluated using biochemical methane potential (BMP) test. The optimal THAP reaction temperature and NaOH concentration of food waste and sewage sludge were $140^{\circ}C$ and 60 meq/L to solubilization COD over 20%, CST and TTF under 60sec and VFAs concentration over 12,000 mg-COD/L, respectively. The optimal condition of co-digestion of mixed food waste and sewage sludge equal to THAP condition. Therefore, it was determined that the optimal condition of THAP reaction temperature and NaOH concentration for co-digestion of mixed food waste and sewage sludge were $140^{\circ}C$ and 60 meq/L, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.565-572
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• 2011

The effects of chemical pretreatments on the excess sludge production in the membrane-coupled bioreactor were investigated. In addition, their effects on membrane fouling were also evaluated. Two membrane bioreactors were operated. In one reactor, a part of the mixed liquor was t reated with NaOH and ozone gas consecutively and was returned to the reactor. T he f lowrate of the chemical pretreatment stream was 1.5% of the influent flowrate. During the 200days of operation, the MLSS level in the bioreactor with mixed liquor pretreatment was maintained relatively constant at the range of 8,000 ~ 10,000$mg/{\ell}$ while it increased steadily up to 26,000 $mg/{\ell}$ in the absence of the pretreatment. Each reactor was equipped with two laboratory membrane modules where the flux for each module was 20, and 30 ${\ell}/m^2{\cdot}h$, respectively. With pretreatment, almost constant transmembrane pressure(TMP) was observed throughout the operation at the flux of 20 ${\ell}/m^2{\cdot}h$. Without pretreatment the membrane module at the same flux could also be operated at relatively stable condition. However, as the MLSS increases up to 25,000 $mg/{\ell}$, a fast TMP increase was observed. In conclusion, a complete control of excess sludge production in the membrane-coupled bioreactor was possible without significant deterioration of the treated water quality. In addition, it was shown that stable operation in terms of TMP is possible with sludge pretreatment and recirculation.

• Composites Research
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• v.37 no.3
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• pp.226-231
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• 2024

Coal ash has been used as a sand replacement in the construction industry. Due to the use of bituminous coal as a result of anthracite depletion, and quicklime as an air purifier in the desulfurization process, pop-out defects have recently occurred in concrete using coal ash, severely limiting the recycling of coal ash into concrete. In this study, the components that cause the pop-out problem of the coal ash filled concrete were identified and a pretreatment method to fully expand the expansive components in advance was proposed as a solution to this problem. By treating water twice for 10 min, allowing the CaO mixed in the coal ash to fully expand, the problems of pop-out and reduced compressive strength of the concrete were overcome. The cost and time efficient water treatment method proposed in this study is expected to promote the recycling of coal ash into concrete.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.681-692
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• 2013

We aimed to evaluate the effectiveness of the Giggenbach bottle method and develop the related pretreatment and analytical methods using artificial fumarolic gases. The artificial fumarolic gases were generated by mixing $CO_2$, CO, $H_2S$, $SO_2$, $H_2$, and $CH_4$ gas streams with a $N_2$ stream sparged through an acidic medium containing HCl and HF, with their compositions varied by adjusting the gas flow rates. The resultant fumarolic gases were collected into an evacuated bottle partially filled with a NaOH absorption solution. While non-condensible gases such as CO, $H_2S$, and $CH_4$ accumulated in the headspace of the bottle, acidic components including $CO_2$, $SO_2$, HCl, and HF that were dissolved into the alkaline solution. Like other acidic components, $H_2S$ also dissolved into the solution, but it reacted with dissolved $Cd^{2+}$ to precipitate as CdS when $Cd(CH_3COO)_2$ was added. The non-condensible gases were analyzed on a gas chromatography. Then, CdS precipitates were separated from the alkaline solution by filtration, and they were pretreated with $H_2O_2$ to oxidize CdS-bound sulfide into sulfate. In addition, a portion of the solution was also pretreated with $H_2O_2$ to oxidize sulfite to sulfate. Following the pretreatment, the resultant samples were analyzed for $SO_4^{2-}$, $Cl^-$ and $F^-$ on an ion chromatography. In the meanwhile, dissolved $CO_2$ was analyzed on a total organic carbon-inorganic carbon analyzer without such pretreatment. According to our experimental results, the measured concentrations of the fumarolic gases were shown to be proportional to the gas flow rates, indicating that the Giggenbach bottle method is adequate for monitoring volcanic gas. The pretreatment and analytical methods employed in this study may also enhance the accuracy and reproducibility of the Giggenbach bottle method.