• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1369-1373
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• 2003

ACE (Angiotensin-I converting enzyme) inhibitory peptides derived from foods are thought to suppress high blood pressure by inhibiting ACE. We tried to make efficient production of the ACE inhibitory hydrolysate from egg albumen. A hydrolysate digested by neutrase presented the highest ACE inhibitory activity ($IC_50\;value=256.35{\mu}g/ml$) and the proper proteolysis was occurred by 1.0% enzyme addition and 4 h incubation at $47^{\circ}C$. Antihypertensive effect of neutrase hydrolysate was investigated in spontaneously hypertensive rats (SHR, n=5). Systolic blood pressure (SBP) was decrease by 6.88% (-14.14 mmHg, p<0.05) at 3 h after oral administration of 300 mg/kg body weight, and by 13.33% (-27.72 mmHg, p<0.05) by emulsified hydrolysate. These results showed that it is very effective to utilize egg albumen as a protein source for the production of ACE inhibitory peptides. However, further studies are required to investigate the methods to increase recovery yield and the isolation of active peptide is necessary for determining its sequence responsible for ACE inhibitory activity.

• 한국습지학회지
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• 제25권4호
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• pp.386-393
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• 2023

최근 들어서 국내의 해양치유산업 활성화를 위한 해양치유자원의 효능·효과에 관한 연구개발이 진행 중에 있다. 본 연구는 해양치유자원으로서 잘 알려진 머드 물질에 대한 효능성분 분석을 통해 활용·관리 기준을 제시하였다. 머드물질 시료는 국내 갯벌에서 채취되었으며, 모래질, 실트질 및 점토질 함량은 각각 평균 7.87%, 74.95% 및 17.17%로 머드(실트+점토)의 평균 함량이 90% 이상이었다. 효능성분은 SiO2(68.4%)성분이 가장 높으며, 다음으로 Al₂O₃(13.3%)>Fe₂O₃(4.0%)>K₂O(2.9%)>Na₂O(2.3%)>MgO(1.6%)>CaO(1.0%)>TiO₂(0.7%) 순으로 평균함량이 높았다. 효능성분 분석을 바탕으로 기능성을 나타내는 성분(기능 성분)을 Si, Al, Fe, K, Na, Mg, Ca를 선정하였으며, 또한 품질관리를 목적으로 정하는 성분(지표 성분)은 효능을 가진 성분 중 함량이 높은 K, Mg, Ca로 결정하였다. 결과적으로 기존 문헌을 참고하여 국내 갯벌머드자원이 해양치유자원으로서 활용·관리되기 위해서는 원재료의 머드함량이 70.0% 이상 그리고 지표 성분인 K₂O+MgO+CaO의 합이 5.0% 이상을 기준으로 제시하였다.

• Ocean and Polar Research
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• 제26권3호
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• pp.415-423
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• 2004

An experiment was conducted to investigate the differences of total ammonia nitrogen (TAN) excretion rates and feces production rates among the offsprings from cultured Japanese strain (JJ, mean BW; $17.1{\pm}0.1g$), intraspecific hybrid strain between cultured Japanese and selected Korean strain (JK, mean BW: $17.1{\pm}0.1g$) and selected Korean strain(KK, mean BW: $21.5{\pm}0.1g$) of red sea bream in order to compare their dietary protein utilization efficiency. Fish were hand-fed with a commercial diet containing 46.7% crude protein for 2 weeks, three times daily 09:00, 13:00 and 17:00. After daily feeding, the TAN excretion rates reached peaks of 49.03, 58.75 and 36.26mg/kg fish/hr for the JJ, JK and KK strain, respectively, during the daytime. The value of the KK strain was significantly lower than that of the JJ and JX shuin (P<0.05), however daily TAN excretion rates of the JJ, JK and KK strain were not different (P>0.05). When fish were fed at satiation after 4 days of starvation, TAN excretion rates reached the maximum values 4 hours after the feeding fur the KK (31.23 mg/kg fish/hr) and 6 hours after the feeding fur the JJ (44.19 mg/tg fish/hr) and JK strain (41.70 mg/kg fish/hr). After 3 days of starvation, the daily endogenous TAU excretion rates (ETE) for the JJ, JK. and KK strain were 286.91, 215.66 and 179.29mg/kg fish/day, respectively. The value of the KK strain was lower than that of the JJ and JK strain (P<0.05). The total feces production rates of the JJ, JK and KK strain were not significantly different, however the proportions of feces production rates by time for the JJ, JK and KK strain were different (P<0.05). As overall results, efficiency of dietary protein utilization of JJ, JK and KK seems to be different and KK strain could offer a desirable option for aquaculture purpose.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.396-400
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• 2002

This study was conducted to evaluate the dry matter (DM) yield, quality and utilization of nutrients in Korean lespedeza (Lespedeza stipulacea Maxim.) swards as a roughage source. DM yield in various stages, chemical composition, and DM digestibility were observed, and DM intake, digestibility and utilization of nitrogen and energy by Korean native goat were determined. Experimental diets include three treatments: mixture hay (MH) 100%, MH (80%)+wild Korean lespedeza hay (LH) 20% and MH (60%)+LH (40%). As growth stage advanced, the DM yield of Korean lespedeza tended to increase significantly (p<0.05). The mean DM yield of all growing stages was observed as 7,336 kg/ha. Crude protein (CP) content of Korean lespedeza tended to decrease, but fibrous contents tended to increase when the growth stage advanced. The tannin content of Korean lespedeza was the highest at the bud stage (64.7 mg/g). However, it showed a tendency to decrease as the growth stage advanced, and thus it was the lowest at the ripe seed stage (26.8 mg/g) (p<0.05). With increasing level of LH, voluntary DM intake by Korean native goats slightly increased, but no differences were observed between diets. The digestibility of DM, cellular constituents and NDF was slightly higher in LH containing diets than that of MH 100% diet (p<0.05). There was no significant difference in apparently digested N% among all diets, but retained N% and retained N% of the absorbed were higher in MH (60%)+LH (40%) than those of other diets (p<0.05). A difference in the utilization of energy was not detected. In conclusion, Juvenile LH improved the digestibility of nutrients, presumably due to its high CP content and low fibrous compound. Especially, tannin in LH did not affect in DM intake, but increased the nitrogen utilization of Korean native goats. Accordingly, it could be suggested that Korean lespedeza has a potential to be provided as a roughage source for Korean native goats.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.357-361
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• 2001

The possibility of producing Cr$_2$O$_3$powder from waste magnesia-chromium refractory was investigated by sulfuric acid reaction, alkali fusion, water leaching & purification and heat treatment. The effects of temperature, the amount of NaOH added and the flow rate of air on chromium extraction efficiency in an alkali fusion step were investigated. The fusion product was leached with methanol to solve free-NaOH, and then leached with water to produce a Na$_2$CrO$_4$solution. The purity of chrome(Ⅵ) oxides, prepared both from monochromate with an impurity content and monochromate purified with $CO_2$were also examined. The purified monochromate solution was reduced from Cr(Ⅵ) to Cr(III) with NaHSO$_3$solution. The reduced solution was neutralized with NaOH to produce Cr(OH)$_3$. Water washing was treated to eliminate Na$_2$SO$_4$from neutralized Cr(OH)$_3$slurry. The washed Cr(OH)$_3$was dried and thermally treated to produce Cr$_2$O$_3$powder. The properties like lightness and hue of Cr$_2$O$_3$fabricated in this study were L=47.47, a=-14.40 and b=17.21.

• 자원리싸이클링
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• 제32권3호
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• pp.26-37
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• 2023

바나듐광 염배소 산물의 수침출 용액으로부터 바나듐을 회수하기 위해서는 수용액의 pH 와 온도 조절 과정이 필요한데, 이 과정에서 알루미늄-바나듐, 소듐-바나듐 공침이 일어나면서 바나듐 회수율에 큰 영향을 미친다. 그러므로 본 연구에서는 바나듐을 회수하기 위한 암모늄메타바나데이트[NH₄VO₃], 암모늄폴리바나데이트[(NH₄)₂V₆O₁₆·H₂O] 침전 과정에서 바나듐 함유 수용액 특성이 이들의 침전에 미치는 영향을 검토하여 바나듐 회수율을 높일 수 있는 회수공정에 대하여 알아보았다. 바나듐 함유 수침출 용액으로부터 암모늄메타바나데이트를 침전시키기 위하여 수용액 pH 9로 조절하는 과정에서 수용액의 알루미늄 함량은 바나듐의 손실에 많은 영향을 미치며, 따라서 수침출 과정에서 알루미늄 침출을 최소화 하는 과정이 필요하다. 수용액 pH 9, 상온에서 바나듐 함량 대비 3당량의 염화암모늄 첨가에 의하여 수용액에 존재하는 바나듐의 약 99% 이상을 암모늄메타바나데이트를 침전회수하였다. 또한 수용액 pH 9로 조절하는 과정에서 발생하는 알루미늄-바나듐 공침전물로부터 암모늄폴리바나데이트 침전를 위해서는 pH 2.5 수용액에 용해시키고, 수용액의 소듐 함량은 2,000 mg/L이하로 조절되어야 한다. 바나듐 함량 2,200 mg/L, 소듐 함량 1,875 mg/L인 수용액 pH 2.5, 온도 95℃ 이상에서 바나듐 함량 대비 약 3당량의 염화암모늄 첨가에 의하여 98% 이상의 암모늄폴리바네데이트를 침전회수하였다. 이와 같은 일괄공정 조건에서 수침출용액의 바나듐 함량 대비 약 91.2% 이상의 바나듐을 암모늄(메타, 폴리)바나데이트로 침전회수하였다.

• Journal of Nutrition and Health
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• 제31권9호
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• pp.1404-1410
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• 1998

The purpose of this study was to investigate the effects of calcium intake levels on magnesium utilization in young and adult rats fed various levels of calcium(50, 100 or 200% of requirement) for 3 weeks. Feed intake, body weight gain, and feed efficiency ratios of the young group were significantly higher than those of the adult group. In calcium levels of tissues, serum calcium levels in young group were higher than in the adult group and kidney calcium levels in HCa(high-calcium group) were higher than in other groups. There was no significant difference in magnesium intake among age and diet groups. However, magnesium excretions through feces and urine in the adult group were higher than in the young group. Therefore, magnesium retention in the young group was higher than in the adult group. Especially in the young group, fecal magnesium excretion was increased with increasing levels of dietary calcium. Serum magnesium levels were lowest in YHCa(young 8t high-calcium) group, and there was no significant difference in liver and kidney levels among the calcium-diet groups. These results indicate that high calcium consumption promotes of fecal magnesium excretion and decreased magnesium retention rates in growing rats. Therefore, it is suggested that mineral interactions should be considered in the supplementation of dietary calcium intake for growth. (Korean J Nutrition 31(9) 1404-1410, 1998)

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.537-541
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• 2001

For the development of reformation material of soft ground using the LD slag, the relation to the particle condition of LD slag and the pH behavior of slag dissolution water, extraction properties of slag, and origination of white water were investigated. When the LD slag is mixed with sea water, the pH of solution ranged between 9.47 and 10.0. On the other hand, when mixed with distilled water, the pH was about 10.4 to 12.1. For the as-received slag and the aged slag in sea water, a pH of 11.5 to 12.0 was observed when the particle size was less than 0.5mm. For the reoxidized slag in seawater, the pH of the solution was lower than 9.5 when the particle size was bigger than 0.075mm. For the aged slag and reoxidized slag, the pH of the solution remained constant when the addition ratio of sea water to the slag was higher than 500 times. The main elements dissolved from the slag were Ca and Mg ions. When the pH went over 9.0, the white water started to font which was caused by the CaCO$_3$and Mg(OH)$_2$.

• Journal of the Korean Wood Science and Technology
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• 제22권1호
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• pp.34-39
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• 1994

Effects of Mg-base acid sulfite and Mg- or Na-base bisulfite on pine bark cooking were examined. In the presence of 75 % free acid at 145 $^{\circ}C$, the rate of cooking and delignification was improved with the increase of total acid. However, the delignification could not be achieved by 50 % or more under these cooking conditions. When cooked with 50~65 % free acid and at 155~165 $^{\circ}C$, the rate of cooking and delignification was remarkably improved. Thus, the bark was delignified up to 73 % when cooked for 2 hours in the presence of 50 % free acid and 24 % total acid. Na-base bisulfite was slightly more effective than Mg-base bisulfite for cooking, giving 76 % delignification of pine bark. However, there was no significant difference in selectivity of delignification between Na- and Mg-base bisulfite cooking.

• 한국토양비료학회지
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• 제33권3호
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• pp.182-192
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• 2000

본 연구는 밭토양에서 종류가 상이한 퇴비시용 시 퇴비시용 한계량을 구명하기 위하여 수행하였다. 공시토양은 양토와 사양토를 사용하였고, 시험에 사용한 퇴비의 종류는 계분퇴비, 우분퇴비, 분뇨잔사 및 식품오니퇴비 이었다. 퇴비 시용량은 0, 40, $80Mg\;ha^{-1}$ 수준이었고, 공시작물은 콩과 옥수수로서 1994년부터 1997년도까지 4년간 연작을 하였으며 주요 연구결과를 요약하면 다음과 같다. 옥수수의 건물생산량은 퇴비 시용량이 증가될수록 증가되었으나 콩은 퇴비 $60Mg\;ha^{-1}$ 시용까지는 증가되다가 그 이상은 감소되었다. 질소와 인산 이용율은 옥수수가 콩보다 많았으며, 질소 이용율은 옥수수가 21~31%, 콩은 8~19%였고, 인산 이용율은 옥수수와 콩이 각각 5~7%. 1~2%로 낮은 편이었다. Biomass기준 계분퇴비 시용 한계량은 옥수수재배시는 $39{\sim}47Mg\;ha^{-1}$ 콩 재배시는 $8{\sim}13Mg\;ha^{-1}$범위 이었다. 작물의 질소 요구량을 기준으로 하였을 경우는 옥수수 $123Mg\;ha^{-1}$, 콩은 $87Mg\;ha^{-1}$였고, 인산기준으로는 옥수수 $29Mg\;ha^{-1}$ 콩은 $14Mg\;ha^{-1}$범위였다. 토양의 염기포화도 80%를 한계수준으로 평가한 토성별 퇴비시용 한계량은 옥수수재배시 양토는 $69{\sim}93Mg\;ha^{-1}$, 사양토는 $49{\sim}69Mg\;ha^{-1}$범위이었다.