• Journal of Biosystems Engineering
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• 제43권4호
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• pp.362-368
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• 2018

Purpose: Self-sufficiency in paper production is desired in Nigeria. This study was aimed at evaluating the performance of a locally fabricated batch pulp digester. Methods: The pulp yields of sheaths generated as waste in the production of bamboo (Bambusa vulgaris) laminates were determined at different liquor concentrations and treatment time after preliminary experiments to ascertain the conditions under which the sheath started to pulp. Moreover, the optimum pulping conditions and fiber characteristics were determined and estimated, respectively, to ascertain the pulp fiber suitability for paper production. Results: An optimum pulp yield of 65.1% was obtained at 50% NaOH and 25% $Na_2S$ liquor concentration (w/w) when the cooking time was 4 h. The results of fiber characterization of the pulp indicated an average fiber length of 2.19 mm with a low Runkel ratio of 1.63, both of which signify the suitability of the pulp for medium quality paper production. Conclusions: Softwood pulp can be blended with the fibers to improve the strength of the produced paper; further investigation should be carried out to use other non-woody plants for pulp and papermaking.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.62-66
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• 1997

The MAA graftings in silk fiber were done by redox system for the purpose of investingating the effect of ferrous sulfate additive on the grafting rate and graft ratio in various conditions. The graft ratio was higher in redox graft system than in peroxide graft system and the graft ratio in redox graft system was also higher depending on decrease of ferrous sulfate additive. The saturation graft ratio obtained by empirical equation, log X=K/t, was increasing depending on the increase of ferrous sulfate additive. Initial grafting rate was increased but the latter grafting rate was decreased in redox graft system. The effects of liquor ratio(L.R.) on the graft ratio in redox graft system, were higher in high L.R. than in low L.R..

• 한국환경과학회지
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• 제28권9호
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• pp.719-727
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• 2019

In this study, the effect on the stability of Aerobic Granular Sludge (AGS) with different Carbon/Nitrogen (C/N) ratios was investigated. The C/N ratios were controlled to 10.0, 7.5, 5.0, and 2.5 using the sequencing batch reactor, and the results showed that the removal efficiency of organic matter and total nitrogen decreased simultaneously with the decrease of C/N ratio. The removal efficiency of organic matter and total nitrogen at C/N ratio of 2.5 was 70.7% and 52.3% respectively. In addition, the AGS/mixed liquor suspended solids (MLSS) ratio showed a tendency to decrease from 85.7% to 73.7%, while the sludge volume index showed a tendency to increase from 82 mL/g to 102 mL/g as the C/N ratio decreased. At the same time, the apparent deviation of polysaccharide (PS) content in extracellular polymeric substances was observed, and polysaccharides/protein (PS/PN) ratio decreased from 0.62 to 0.31 as the C/N ratio decreased. Optical microscope observations showed that the reduction in C/N ratio caused the growth of filamentous bacteria and significantly affected the stability of AGS.

• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.313-320
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• 2014

Black liquor (BL) is a by-product of rice straw pulping process. It is a low costs raw material for production value-adding proteins and enzymes, which has been paid more and more attention to reduce its environmental pollution. Mixed cultures of micelial fungi, Trichoderma reesei Northern Regional Research Laboratory (NRRL)11236, Trichoderma reesei NRRL 6165 and Aspergillus niger strains NRC 5A, NRC 7A, and NRC 9A were evaluated for their ability to produce xylanase using crude hemicellulose (CHC) prepared from BL and peat moss as an inert support under solid state fermentation (SSF). The most potent strains, A. niger NRC 9A (818.26 U/g CHC) and T. reesei NRRL 6165 ($100.9{\pm}57.14$ U/g CHC), were used in a mixed culture to enhance xylanase production by co-culturing under SSF. In the mixed culture, xylanase production ($1070.52{\pm}12.57$ U/g CHC) was nearly1.3 and 10.6-fold increases over the activities attained in their monocultures, A. niger NRC 9A and T. reesei NRRL 6165, respectively. Optimization of the culture parameters of the mixed culture SSF process, concentration of ammonium sulfate and corn steep liquor, CHC/peat moss ratio, inoculum size and ratios of the two strains, initial pH value, initial moisture content and incubation time, exhibited a significant increase ($2414.98{\pm}84.02$ U/g CHC) in xylanase production than before optimization.

• 자원리싸이클링
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• 제14권6호
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• pp.37-43
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• 2005

페리튬이온전지로부터 회수된 코발트와 리튬 침출액으로부터 화염분부열분해법에 의하여 $LiCoO_{2}$ 나노분말을 제조하였다. 리튬 및 코발트 성분을 함유하는 전극물질은 열처리 및 기계적 처리에 의해 그 농도를 증가 시켰다. 리튬이온전지 양극물질을 질산으로 용해한 다음 침출액중 Li과 Co의 당량비가 1.0 되도록 $LiNO_{3}$로 조절하여 화염분무열분해용 전구체를 제조하었다. 화염분무열분해법에 의해 제조된 $LiCoO_{2}$ 분말의 평균입자크기는 전구체의 몰 농도가 증가하면서 증가되었으며, 화염온도 역시 입자의 크기를 증가시켰다. 변수실험 결과 $11{\~}35nm$ 크기의 결정형 $LiCoO_{2}$ 나노분말을 제조할 수 있었다 또한 나노 $LiCoO_{2}$의 전극재료로서의 가능성을 확인하기 위하여 충방전 특성 평가와 같은 전기화학적 분석을 수행하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.402-405
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• 2001

The production of fumaric acid in shaken flask cultures by Rhizopus oryzae KCTC 6946 was studied. The effects of various carbon and nitrogen sources on fumaric acid production were investigated. The strain fermented starch (or glucose) and corn steep liquor (or polypepton) better than other carbon and nitrogen sources to fumaric acid. When C/N ratio of carbon and nitrogen source was 41.7, the concentration of fumaric acid produced with 2N NaGH as a neutralizing agent was more than 10 g/L after 3 days.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.119-122
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• 2007

• 한국의류학회지
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• 제23권1호
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• pp.14-21
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• 1999

The Tencel fabrics were treated with bio-softness finish to improve softness. The change of the properties depending on the softner as well as cellulase treatment was investigated. The relative activity of cellulase for tencel was maximum ap pH 4-4.3 cellulase concentration 14-16% (o. w .f) treatment time 4 hour and liquor ratio 100: 1 The treatment of epoxy silicon softner improved in pilling whiteness dye absorption of Tencel fabric.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.861-868
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• 2020

The use of polyphenol extracts from radiata pine (Pinus radiata) bark as raw materials for bio-foams was investigated along with the optimal NaOH extraction conditions. The targeted yield of alkaline extracts was 60%, and the targeted pH was 11 to 12. The radiata pine bark was composed of 70% of a 1% NaOH extract, which contained mainly polyphenols, such as proanthocyanidin (PA). As the particle size of the bark decreased, the yield of the 1% NaOH extracts increased from 57 to 87%. A range of NaOH concentrations, liquor ratios, and extraction times were explored to establish an economic polyphenol extraction method. More than 60% of the alkaline extract was extracted, and the pH of the extract was approximately 12 when the optimum extraction conditions were employed, i.e., a liquor to bark ratio of 5:1, a NaOH dosage of 17 to 18% based on the bark weight, and a 1 h extraction time. Following neutralization of the alkaline extract, structural analysis indicated severe structural changes in the PA during the alkaline extraction. Because the alkaline extract was barely soluble in the solvent used for the structural analyses, it is assumed that chemical modification is required to increase the solubility of the alkaline extract for the production of bio-foams.

• KSBB Journal
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• 제26권6호
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• pp.529-532
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• 2011

Whey based medium was optimized for the production of viable Lactobacillus crispatus KLB 46 isolated from the vagina of Korean women. Among the various nitrogen sources such as yeast extract, beef extract, and proteose peptone no. 3 supplemented to whey, beef extract showed the highest viable cell production. The addition of Tween 80 to the whey based medium increased viable cell concentration. As beef extract supplementation is not economically attractive, corn steep liquor was added as a supplementary nitrogen sources. When corn steep liquor was supplied with beef extract with the ratio 5 : 1, the viable cell count was $3.11{\times}10^9$ CFU/mL. Also, the addition of mineral salts containing sodium acetate (5 g/L), potassium phosphate dibasic (2 g/L), magnesium sulfate (0.1 g/L) and manganese sulfate (0.05 g/L) to the whey medium increased viable cell count further ($5.00{\times}10^9$ CFU/mL).