• 생명과학회지
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• 제9권5호
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• pp.612-619
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• 1999

The effects of anti-stress rose fruit (ASRF) extract drink (ASRF-0.1% and ASRF-0.5% concentrations) were tested for the anti-stress action. ICR male mice (20$\pm$2 g) were fed with basic experimental diets and given free access to water containing these ingredients for 18 days. Psychological stress/sociopsychological stress exposed by foot-shock for 1 hour for 3 days. Both ASRF-0.1 and ASRF-0.5 groups in the sociopsychological stress resulted in a significant decrease of 24.3% and 38.0% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretion in the brain were significantly increased 35.9% in ASRF-0.5 group, but NA secretion in ASRF-0.1 group could not be obtained significant result compared with control group. MHPG-SO4 (3-Methoxy-4-hydroxy-phenylethy leneglycol sulfate) levels in the brain resulted in a marked decreases of 16.5% and 18.9% respectively in ASRF-0.1 and ASRF-0.5 groups. NA/MHPG-SO4 ratios in the brain of ASRF-0.1 and ASRF-0.5 groups resulted in a significantly increase of 16.5% and 67.0%, respectively, compared with control group. These results suggest that anti-stress rose fruit (ASRF) drink also can effectively ridded the sociopsychological stress.

• 유기물자원화
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• 제30권3호
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• pp.23-28
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• 2022

Fe(II)/Na₂S₂O₈을 이용하여 하수슬러지의 탈수능 개선 여부를 확인하고자 약품 주입량에 따른 탈수능을 비교하였다. 탈수능의 주요 지표로 STTF, SCST, 함수율, TS, VS를 분석하였으며 TB-EPS as carbohydrate 및 protein을 측정하여 EPS의 파쇄여부를 확인하였다. 실험한 Na₂S₂O₈ 농도 범위는 0.4~0.7 mmol.gVS였고, Fe(II)/Na₂S₂O₈ 몰비 범위는 0.5~0.7 mol/mol이었다. 실험결과, Fe(II)/Na₂S₂O₈의 농도 및 몰비가 증가함에 따라 STTF는 초기 1.00에서 15.00까지 증가하였고, SCST는 1.00에서 4.51까지 증가하였다. 함수율은 82.6%까지 감소하였다. TB-EPS as carbohydrate 및 protein의 감소율은 각각 37.16% 및 57.34%까지 증가하였다. Na₂S₂O₈ 0.6 mmol/gVS, Fe(II)/Na₂S₂O₈ 0.6 mol/mol 조건에서 STTF, SCST 및 함수율은 각각 13.64, 4.19 및 83.1%로 주입량 대비 탈수능 개선효과가 높게 나타났다. 이는 Fe(II)에 의해 생성된 SO₄^- 라디칼이 EPS를 파쇄하여 EPS와의 결합된 수분과 세포수를 수용액으로 용출시켜 탈수능이 개선된 것으로 사료된다.

• 한국세라믹학회지
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• 제17권4호
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• pp.208-212
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• 1980

In order to clarify the mechanism of the hydration of supersulphated slag cement, the experiments of suspension hydration were performed in the mixtures of slag+CaSO4+water or NaOH solutions with a liquid/solid ratio of 10. The liquid and solid phase of the suspension was chemically analysed and discussed. In the slag-$CaSO_4$--NaOH system, $Al_2O_3$ was dissolved under high pH condition, and the ettringite was formed by a reaction of $CaSO_4$ and $Al_2O_3$ released in the solution. As hydration progressed, ettringite coated the surface of unhydrated slag grains and inhibited the hydration reaction of slag. $CaSO_4$ was not only an activator for slag hydration, but a reactant in the hydration.

• 자원리싸이클링
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• 제31권2호
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• pp.49-55
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• 2022

본 연구에서는 국내 부존 바나듐 광물인 포천 지역의 바나듐 함유 함티탄철석(VTM: Vanadium-bearing titaniferous magnetite)을 대상으로 하여, 바나듐 회수를 위한 황화 배소 반응의 열역학적 평가를 수행하였다. Na₂SO₄를 이용하여 황화 배소를 진행하는 경우, 배소조건에 따른 배소 후 바나듐 및 불순물의 수침출 거동을 평가하고, 황화 배소 반응에 대한 메커니즘 규명을 위하여 열역학적 평가를 수행하였다. Na₂SO₄를 이용한 황화 배소의 경우 Na₂CO₃를 이용한 염배소 공정과 비교하여 반응 온도는 200 ℃ 정도 높았지만 바나듐 침출률이 높고 Al, Si 등의 불순물에 대한 낮은 침출률을 보였다. 바나듐만 선택적으로 수침출되는 황화 배소 반응의 특징은 기상의 SO₂ 가스와 정광내 바나듐간의 반응에 따른 반응 메커니즘에 기인하는 것으로 예상되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.129-130
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• 2021

In order to solve the problem of low early-age compressive strength of high volume fly ash concrete. This paper studies the effect of 2% sodium sulfate (Na₂SO₄) as a chemical activator on the paste with 40% fly ash content and a water-binder ratio of 0.30. The results indicate that the addition of Na₂SO₄ can effectively improve the early-age compressive strength of the fly ash-cement system, and the strength improvement rate on the first day reached nearly 70%. In addition, calorimetric analysis reveals that the incorporation of Na₂SO₄ promotes the early hydration of cement and fly ash, increases the cumulative hydration heat and delays the heat peak of the aluminum phase.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.490-496
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• 2002

The production of E. coli WC7 phytase from a recombinant E. coli strain was optimized using a statistical experimental design approach. Two-level complete factorial designs with seven variables were used for the media optimization. In the first optimization step, the influence of disodium succinate, yeast extract, $K_2HPO_4,\;NH_4H_2PO_4,\;MgSO_4$, NaCl, and trace elements on phytase production was evaluated. As a result, disodium succinate, yeast extract, $NH_4H_2PO_4$, NaCl, and the trace elements were found to have a positive influence on the phytase production, while $K_2HPO_4\;and\;MgSO_4$ had a negative influence. In the second step, the concentrations of disodium succinate and yeast extract were further optimized using central composite designs. The maximum phytase activity obtained was 234 U/ml using 15.9 g/1 disodium succinate, 20 g/1 yeast extract, 5 g/1 K_2HPO_4,\;10 g/1 NH_4H_2PO_4,\;1.5 g/1 MgSO_4$, 4 g/1 NaCl, and 1.5 m1/1 trace elements, which was about a 14-fold increase in comparison with that obtained using the basal medium.

• 자원리싸이클링
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• 제15권6호
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• pp.10-15
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• 2006

오리멀젼 소각 후 발생되는 배출물 중 함유되어 있는 바나듐과 니켈의 유가금속을 회수, 재활용하기 위한 기초연구로써, 오리멀젼회로부터 얻어진 바나듐과 니켈함유 중간생성물을 사용해서 $Na_2CO_3$ 침출과 암모니아 침출로부터 바나듐과 니켈을 각각 선택적으로 침출하는 방법에 대하여 검토하였다. 실험결과 $Na_2CO_3$ 침출의 경우 $Na_2CO_3$ 50g/L, 반응시간 1시간, 반응온도 $25^{\circ}C$ 그리고 산화제로서 35% $H_2O_2$를 50ml/L 첨가 시 바나듐은 97%이상 침출되었으나, 니켈은 녹지 않았다. 한편 암모니아 침출의 경우, $NH_4OH$ 2M, $(NH_4){_2}SO_4$ 1.5M, 광액비 50g/L, 반응시간 4시간, 반응온도 25에서 니켈과 바나듐은 각각 95%, 3% 침출되었다.

• 한국환경보건학회지
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• 제40권2호
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• pp.137-146
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• 2014

Objectives: Feasibility of electrochemical oxidation of the aqueous non-biodegradable wastewater such as cationic dye Rhodamine B (RhB) has been investigated in an electrochemical reactor with solid polymer electrolyte (SPE). Methods: Nafion 117 cationic exchange membrane as SPE has been used. Anode/Nafion/cathode sandwiches were constructed by sandwiching Nafion between two dimensionally stable anodes (JP202 electrode). Experiments were conducted to examine the effects of applied current (0.5~2.0 A), supporting electrolyte type (0.2 N NaCl, $Na_2SO_4$, and 1.0 g/L NaCl), initial RhB concentration (2.5~30.0 mg/L) on RhB and COD degradation and $UV_{254}$ absorbance. Results: Experimental results showed that an increase of applied current in electrolysis reaction with solid polymer electrolyte has resulted in the increase of RhB and $UV_{254}$ degradation. Performance for RhB degradation by electrolyte type was best with NaCl 0.2 N followed by SPE, and $Na_2SO_4$. However, the decrease of $UV_{254}$ absorbance of RhB was different from RhB degradation: SPE > NaCl 0.2 N > $Na_2SO_4$. RhB and $UV_{254}$ absorbance decreased linearly with time regardless of the initial concentration. The initial RhB and COD degradation in electrolysis reaction using SPE showed a pseudo-first order kinetics and rate constants were 0.0617 ($R^2=0.9843$) and 0.0216 ($R^2=0.9776$), respectively. Conclusions: Degradation of RhB in the electrochemical reactor with SPE can be achieved applying electrochemical oxidation. Supporting electrolyte has no positive effect on the final $UV_{254}$ absorbance and COD degradation. Mineralization of COD may take a relatively longer time than that of the RhB degradation.

• 한국식품위생안전성학회지
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• 제10권4호
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• pp.231-237
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• 1995

해양에서 분리한 용균활성이 우수한 균주인 Bacillus subtilis SH-1의 배양특성을 조사하여 다음과 같은 결과를 얻었다. Bacillus subtilis SH-1에 의한 용균효소 생산을 위한 치적조건인 1.0% glucose, 1.0% yeast extract, 1.0% NaCl, 0.02% $K_2HPO_4,\;0.002%\;MgSo_4{\cdot}7H_2O,\;0.001%\;MnSO_4{\cdot}5H_2O,\;0.0001%\;FeSO_4{\cdot}7H_2O\;(ph\;8.0)$의 배지로 $30^{\circ}C$에서 진탕배양하여 배양 28시간일 때 효소활성이 가장 높았다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권3호
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• pp.389-396
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• 1994

Effects of chemical treatments on in sacco and in vitro digestibility of barley straw by rumen fluid and pure cultures of cellulolytic bacteria were studied to evaluate the pretreatment and to improve the poor quality feed. Chemicals were applied by dissolving them in water equivalent to 40% of the weight of the straw (dry matter basis). Pretreatment with 5% NaOH yielded the largest increase in sacco digestion followed by pretreatment with 2% $(NH_4)_2SO_3$, 2.6% $NH_4OH$, 1.6% $NaHSO_3$ and untreated straw (control). In sacco dry matter digestibility of straw treated with NaOH and $(NH_4)_2SO_3$ continued to increase as the concentration of chemical increased (1 to 7.5%), as it was the in vitro dry matter loss by leaching. Treatment of barley straw with 5% NaOH enhanced significantly (p < 0.01) in vitro digestibility by rumen fluid, Fibrobacter suceinogenes and Ruminococcus albus though the fermentation products by cellulolytic bacteria were low, whereas the treatment with 5% $(NH_4)_2SO_3$ inhibited in vitro digestibility by F. succinogenes and R. albus together with lower fermentation products. Dry matter loss by leaching and bacterial digestion from barley straw treated with NaOH and $(NH_4)_2SO_3$ suggested the effect of pretreatment with these chemicals were based on leaching, and the cellulolytic bacteria had little to do with digestion.