• 한국축산시설환경학회지
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• 제12권2호
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• pp.95-100
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• 2006

양돈액비에서 인을 회수하기 위한 연속식 공정을 개발하고자 시험을 수행하였다. $MgCl_2$를 마그네슘 원으로 사용하였고 pH를 NaOH로 조정해준 구와 폭기를 시켜준 구를 서로 비교하였다. 몰비가 증가할수록 용해인의 회수율도 증가함을 알 수 있었다. 1. pH를 NaOH로 조정하였을 때 비육돈사 액비의 경우에 용해인은 몰비 1:1.5에서 초기값 353(${\pm}9$)mg/L에서 19(${\pm}1.6$)mg/L로 감소하여 95%의 회수효과를 보았으며, 암모니아성 질소의 경우에는 5,527(${\pm}174$)mg/L에서 5,009(${\pm}161$)mg/L로 감소하여 9%의 제거율을 나타내었다. 2. 자돈사 액비의 경우에 몰비 1:1.5에서 용해인은 초기치 111(${\pm}2.8$)mg/L에서 1(${\pm}1.1$)mg/L로 감소하여 회수율은 98%를 나타내었으며, 암모니아성 질소의 경우에는 2,317 (${\pm}37$)mg/L에서 2,226(${\pm}39$)mg/L으로 감소하여 제거율 4%를 나타내었다. 3. 자돈사 액비의 경우에 폭기공정의 몰비 1:1.5에서 용해인은 초기값 321(${\pm}10.2$)mg/L에서 113(${\pm}3.6$)mg/L로 감소하여 회수율은 66%로 되었으며, 암모니아성 질소의 경우에는 2,364(${\pm}5$)mg/L에서 2,017(${\pm}2$)mg/L로 낮아져서 제거율은 15%로 높게 나타났다. 4. pH를 NaOH로 조정해준 구가 폭기를 시켜준 구보다 용해인 회수에서 효과가 좋았다. 암모니아성 질소의 제거에서는 반대로 폭기구에서 높게 나타났다.

• 한국초전도ㆍ저온공학회논문지
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• 제19권1호
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• pp.22-25
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• 2017

Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

• Advanced Composite Materials
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• 제18권4호
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• pp.315-326
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• 2009

PCC (precipitated calcium carbonate) and ground calcium carbonate have been widely used in alkaline papermaking. Unfortunately, although increasing filler level in papers can improve the paper properties such as brightness, opacity, stiffness gloss, smoothness, porosity, and printability, as well as decrease cost, some strength of the paper is negatively affected. In this research, needle-like aragonite was synthesized using $Ca(OH)_2$ and $CO_2$ as reactants in the presence of $MgCl_2$ and characterized with scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The physical and optical properties of the paper handsheets containing these needle-like aragonite fillers were evaluated. Results indicated that tensile strength, Z-direction tensile strength and folding endurance of the paper were improved by the needle-like aragonite crystals compared to the paper using commercial PCC (precipitated calcium carbonate) as filler. The stiffness of the paper handsheet on the machine direction was increased, but no evident difference in the cross direction was found. The improvement of paper strength mainly resulted from the twining effect between the aragonite whiskers and paper fibers. The optical properties of the paper were slightly decreased with the use of the needle-like aragonites compared to commercial PCC. These results suggest that paper cost can be decreased by increasing the content of needle-like aragonite filler while paper strength will not be decreased compared to PCC filler.

• 약학회지
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• 제39권6호
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• pp.577-584
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• 1995

On the combination of antacid, the pharmacokinetics and gastric adhesion of [$^{14}c$]aceglutamide aluminium complex([$^{14}C$]AGA) were examined in rats. Specially, this study was focused on the drug interaction that the co-administration of antacid may affect the oral absorption and gastric adhesion of aceglutamide aluminium complex(AGA). In the study of the oral co-administration of [$^{14}C$] AGA and antacid(aluminium hydroxide and magnesium hydroxide(AM)), the radioactivity of plasma and urinary recovery was lower than that of [$^{14}C$]AGA alone administered group. However, the cumulative recovery of radioactivity in feces was increased significantly. The comparative bioavailability of [$^{14}C$] AGA from the plasma concentration-time curve and urinary recovery was about 60%. In vitro, the effect of antacid on the gastric adhesion of AGA was not significatly different between AGA and AGA/antacid treatment. And it accorded well with the result of in vivo experiment. In conclusion, on the combination of antacid, the oral absorption of AGA was decreased by the gastric adhesion was not affected in respect of drug interaction.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.313-318
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• 2006

A two-stage process of nanofiltration and water-splitting electrodialysis was investigated for lactic acid recovery from fermentation broth. In this process, sodium lactate is isolated from fermentation broth in the first stage of nanofiltration by using an NTR-729HF membrane, and then is converted to lactic acid in the second stage by water-splitting electrodialysis. To determine the optimal operating conditions for nanofiltration, the effects of pressure, lactate concentration, pH, and known added impurities were studied. Lactate rejection was less than 5%, magnesium rejection approximated 45%, and calcium rejection was at 40%. In subsequent water-splitting electrodialysis, both the sodium lactate conversion to lactic acid and sodium hydroxide recovery, were about 95%, with a power requirement of $0.9{\sim}1.0\; kWh$ per kg of lactate.

• 한국임상수의학회지
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• 제20권3호
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• pp.406-409
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• 2003

We found seventeen dairy cattle with the abnormal signs in cardiovascular and gastrointestinal systems after feeding of the yew foilage. Among them three cattle were dead due to yew poisoning. Among the remaining fourteen dairy cattle, four cattle showed similar symptoms as did dead cattle. Although the remaining ten dairy cattle did not show any abnormal signs, we conducted a therapy of forced magnesium sulfate infusion because the yew consumption might have been occurred in all cattle. As a result of the therapy, we could not found further signs of yew poisoning. The performance of the therapy and the treatment procedures adapted by the therapy could be concluded as follows: The cardioselective toxicity and inhibition of peristaltic activity by the taxine in yew foilage might be involved in the symptoms of acute poisoning as anorexia, dullness, muscle tremor, dyspnea, and sudden death. We also performed the dose response relationship of taxine to the range of clinical symptoms and examined recovery performances. Through the autopsy of the cattle, we could confirm the presence of yew foilages that might have caused the poisoning in the gastrointestinal tract. However, we could not identify further abnormalities in other organs. In this case report, we demonstrated that practice of the forced magnesium sulfate infusion in yew poisoning was helpful for the attenuating the taxine poisoning by blocking the further proceeding of the toxic effect.

• 소성∙가공
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• 제17권1호
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• pp.13-18
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• 2008

Mg and Mg alloys are promising materials for light weight high strength applications. In this paper, grain refinement of pure Mg using severe plastic deformation was tried to enhance the mechanical properties of the hard-to-deform metallic material. The microstructure and the mechanical properties of Mg processed by equal channel angular pressing(ECAP) at various processing temperatures were investigated experimentally. ECAP with channel angle of $90^{\circ}$ and corner angle of $0^{\circ}$ was successful at $300^{\circ}C$ without fracture of the samples during the processing. The hardness of the ECAP processed Mg decreased with increasing ECAP processing temperature. The effect of temperature on the hardness and microstructure of the ECAP processed Mg were explained by the dislocation glide in the basal plane and non-basal slip systems and by the dynamic recrystallization and recovery.

• Environmental Engineering Research
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• 제21권1호
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• pp.29-35
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• 2016

This study evaluated the fertilizing value of struvite deposit recovered from swine wastewater in cultivating lettuce. Struvite deposit was compared to complex fertilizer, organic fertilizer and compost to evaluate the fertilizing effect of struvite deposit. Laboratory pot test showed that the struvite deposit better enhanced lettuce growth in comparison to commercial fertilizers. It was revealed that the growth rate of lettuce was simultaneously controlled by phosphorus (P) and magnesium (Mg). Moreover, nutrients such as nitrogen (N), P, K, calcium (Ca) and magnesium (Mg) were abundantly observed in the vegetable tissue of struvite pot. Meanwhile, struvite application led to the lower accumulation of mercury (Hg), lead (Pb), chromium ($Cr^{6+}$) and nickel (Ni). In addition, no detection of cadmium (Cd), arsenic (As) and nickel (Ni) in the lettuce tissue was observed in struvite application pots. The experimental results proved that the optimum struvite dosage for lettuce cultivation was 0.5 g struvite/kg soil. The column experiments clearly showed that ammonia nitrogen was more slowly released from struvite deposit than from complex fertilizer. Consequently, it was concluded that the struvite deposits recovered from swine wastewater were effective as a multi-nutrient fertilizer for lettuce cultivation.

• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1624-1628
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• 2015

Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

• 한국토양비료학회지
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• 제29권3호
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• pp.255-263
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• 1996

풍농비료(豊農肥料)의 분상(粉狀) 용성인비(熔成燐肥)를 대조로 하고, 입상화 제조시 상이한 첨가물질에 의해 제조된 분상(粉狀) 용성인비(熔成燐肥) 3제품(製品)(경기화학(京畿化學) 풍농비료(豊農肥料), 수입(輸入) 중국산(中國産))의 시용이 대두(大豆)의 종실수량(種實收量)에 미치는 영향을 비교 검토하였다. 참고로 수용성 인산질비료의 과석(過石)과 수용성과 구용성 인산이 반반씩 함유된 용과린(熔過燐)도 처리하여 제주도(濟州道) 화산회토(火山灰土)(남원통(南元統)) 포장(圃場)에서 비효시험을 실시한 결과를 요약하면 다음과 같다. 1. 대두(大豆)의 종실수량(種實收量)은 풍농비료(豊農肥料)의 분상(粉狀) 용성인비(熔成燐肥) 제품(製品)이 가장 많았고 그 다음이 수입 중국산 입상 용성인비 제품이었으며 경기화학의 입상 용성인비 제품의 수량이 가장 낮은 경향이었으나 분상(粉狀) 용성인비(熔成燐肥) 제품간(製品間)의 수량은 통계적 유의성(有意性)이 없었다. 2. 수량(收量)과 수량구성요소간(收量構成要素間)에는 일정한 경향을 찾을 수 없었으나 수량(收量)이 많았던 처리를 중심으로 해서 보면 주경절수(主莖節數), 분지수(分枝數) 및 꼬투리수의 영향(影響)이 큰 것으로 보여졌다. 3. 수확기(收穫期) 식물체(植物體) 지상부(地上部)(줄기 + 협실(莢實))의 인산함양(燐酸含量)이 생육기간중 식물체 경엽중의 인산함량 보다 높았으며, 수확기(收穫期)의 인산흡수풍(燐酸吸收豊)과 인산이용율(燐酸利用率)이 대두의 수량증수와 비슷한 경향을 보여 수량(收量)에 가장 큰 영향을 주었던 것으로 판단되었다. 4. 시기별(時期別) 토양중(土壤中) pH변화(變化)는 인산질비료(燐酸質肥料)를 시용하므로써 증가추세를 보였고, 수입(輸入) 중국산(中國産) 입상용성(粒狀熔成) 인비제품(燐肥製品)의 pH가 국내산 입상 용성인비 제품 보다 높았으나 과석(過石)과 비교해서는 서로 비슷하였으며 토양중(土壤中) 유효이산함량(有效理酸含量)은 풍농비료(豊農肥料)의 입상(粒狀) 용성인비(熔成燐肥) 제품(製品)이 수입 중국산 입상 용성인비 제품 보다 오히려 더 높았다.