• 한국임상수의학회지
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• 제21권2호
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• pp.109-114
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• 2004

The effect of Human Menopausal Gonadotropin(hMG) on the implantation, pregnancy, and the concentration of plasma progesterone were studied in pregnant rats. HMG 75 or 150 IU were administered once on day 1, 2, 3, 4, 9, 12 or 14 of gestation, respectively. Rats were autopsied on day 7 or 18. A single dose of hMG prevented implantation and terminated pregnancy in all of the rats by injecting on either day 1 or day 2 and this abortifacient action was effective 82-98% of pregnant rats on day 3 or 4 and 14-20% on day 9 or 12. Administration of hMG had no effect on termination of pregnancy on day 14. Plasma progesterone concentration by injecting hMG on day 1, 2, 3 or 4 were very decreased.

• 한국양식
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• 제19권1호
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• pp.34-42
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• 2007

양식 넙치 및 조피볼락을 이용하여 1시간 동안 포르말린(37% 포름알데히드) 100 mg/l, 300 mg/l 및 500 mg/l의 농도에서 약욕 처리한 후 근육 내에서의 포름알데히드 잔류 농도를 측정하였다. 또한 포르말린 농도 25 mg/l, 50 mg/l, 100 mg/l, 150 mg/l 및 200 mg/l의 에어레이션된 해수와 에어레이션이 공급되지 않은 해수에서의 포름알데히드의 손실율을 측정하였다. 1시간 500 mg/l의 포르말린으로 취급된 어류 근육의 포름알데히드 농도는 약욕(0 h 투여 중지) 후 즉시 분석된 대조구 조직의 포름알데히드 농도보다 유의적으로 높게 나타났다(p<0.05). 그러나 대조구 조직내 포름알데히드 농도는 포르말린에 노출 후 24, 48 및 72시간 지난 후 샘플된 어류조직에서의 농도와 유의적인 차이가 없었다(p>0.05). 25-200 mg/l의 포르말린이 포함된 해수의 포름알데히드는 $8{\sim}19$일 이내에 측정 가능한 아주 낮은 농도($0.05\;{\mu}g/ml$)로 되어지나, 그것의 분해는 에어레이션을 함으로서 $6{\sim}10$일 이내로 빨라졌다. 따라서 본 연구에서 밝혀진 것들은 어류양식산업에 있어서 포르말린의 적정 투여 중지 기간과의 결정에 필요한 자료를 제공한다고 생각된다.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1328-1334
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• 2006

This paper aimed to study the toxicity of arsanilic acid on rat primary hepatocytes in vitro by a modification of the perfusion method. The conditions included concentrations of 0, 1.085, 10.85, 108.5, 1,085 and 10,850 mg/kg arsanilic acid in RPMI 1,640 medium at rat hepatocytes plates respectively, each group had five repeats at $37^{\circ}C$ for 48 h. The rat primary hepatocytes survival ratio, DNA Ladder, activities of glutathione peroxidase (GSH-px), superoxide dismutase (SOD) and catalase (CAT) in hepatocytes, activity of SOD in the medium and the expression of gene bax in hepatocytes were measured at 12 h, 24 h and 48 h respectively. The results showed that arsanilic acid decreased the activities of GSH-px and SOD, and increased the activity of CAT in all dosages, and affected as positive DNA ladder. Although the SOD activities of both hepatocytes and medium in 1.085 mg/L arsanilic acid were significantly lower than the base line at 12 h, CAT activity in 10.85 mg/L arsanilic acid was significantly higher than the base line at 48 h, and all of the DNA ladders were positive, which means 1.085 mg/L arsanilic acid induced apoptosis at 24 h. The gene expression of bax was significantly upregulated in 1.085 mg/L arsanilic acid or higher for 24 h.The parameters in 1,085 mg/L and 10,850 mg/L arsanilic acid had more severe changes than the others at any time indicating that these levels of arsanilic acid were toxic hazards for hepatocyte survival. It was concluded that arsanilic acid induced a dosage- and time-dependent gene expression of bax, 1.085 mg/L arsanilic acid could be involved in rat liver cell apoptosis at 24 h. Arsanilic acid as additives in livestock feed could present potential toxic implications for farm animals.

• The Korean Journal of Ceramics
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• 제3권3호
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• pp.187-190
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• 1997

The aluminum-magnesium (Al-Mg) aklloys have been proved to be an effective solvent for synthesis of cubic-phase boron nitride (cBN) from hexagonal-phase boron nitride (hBN) at the conditions of high pressures and high temperatures (HP/HT). Various kinds of hBN powders having different crystallinity have been tested for cBN synthesis with Al-Mg solvents. The conversion ratio from hBN to cBN and the shape of synthesized cBN crystals appeared to be affected strongly by chemical composition and added amount of Al-Mg solvents as well as crystallinity of BN powders. As the magnesium content increased in the Al-Mg solvents, the conversion ratio increased and the size of cBN crystals became larger. The crystal facets developed well in the specimens with solvents having high Mg content. It was observed that a hBNlongrightarrowcBN transformation occurred more easily in the specimens having well crystallized hBN powders. Amorphous BN having much $B_2O_3$ impurity exhibited a low threshold temperature for transformation to cBN, which was attributed to crystallization of amorphous BN to well crystallized hBN prior to transformation into cBN with help of $B_2O_3$.

• 한국표면공학회지
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• 제45권5호
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• pp.206-211
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• 2012

Process analysis was carried out during deposition of MgO by inductively coupled plasma assisted reactive magnetron sputtering in Ar and $O_2$ ambient. At the initiation of Mg sputtering with bipolar pulsed dc power in Ar ambient, total pressure showed sharp increase and then slow fall. To analyse partial pressure change, QMS was used in downstream region, where the total pressure was maintained as low as $10^{-5}$ Torr during plasma processing, good for ion source and quadrupole operation. At base pressure, the major impurity was $H_2O$ and the second major impurity was $CO/N_2$ about 10%. During sputtering of Mg in Ar, $H_2$ soared up to 10.7% of Ar and remained as the major impurity during all the later process time. When $O_2$ was mixed with Ar, the partial pressure of Ar decreased in proportion to $O_2$ flow rate and that of $H_2$ dropped down to 2%. It was understood as Mg target surface was oxidized to stop $H_2$ emission by Ar ion sputtering. With ICP turned on, the major impurity $H_2$ was converted into $H_2O$ consuming $O_2$ and C was also oxidized to evolve CO and $CO_2$.

• 대한금속재료학회지
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• 제49권4호
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• pp.298-303
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• 2011

Mg-23.5 wt%Ni-xwt%Cu (x = 2.5, 5 and 7.5) samples for hydrogen storage were prepared by melt spinning and crystallization heat treatment from a Mg-23.5 wt%Ni-5 wt%Cu alloy synthesized by the gravity casting method. They were then ground under $H_2$ to obtain a fine powder. Among these samples the Mg-23.5Ni-2.5Cu sample had the highest hydriding and dehydriding rates after activation. The Mg-23.5Ni-2.5Cu sample absorbed 3.59 and 4.01 wt%H for 10 and 60 min, respectively, at 573K under 12 bar $H_{2}$. The activated 88(87.5Mg-10Ni-2.5Cu)-$5Nb_{2}O_{5}-7NbF_{5}$ sample absorbed 2.93 wt%H for 10 min, and 3.14 wt%H for 60 min at 573K under 12 bar $H_{2}$.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.456-459
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• 2000

A pilot scale experiment was performed for a year to develop a two-phase anaerobic process for piggery wastewater treatment (COD: 6,000mg/L, BOD: 4,000mg/L, SS: 500mg/L, pH 8.4, alkalinity 6,000mg/L). The acidogenic reactor had a total volume of 3㎥, and the methanogenic reactor, an anaerobic up-flow sludge filter, combining a filter and a sludge bed, was also of total volume 3㎥(1.5㎥ of upper packing material). Temperatures of the acidogenic and methanogenic reactors kept at 20$^{\circ}C$ and 35$^{\circ}C$, respectively. When the pH of the acidogenic reactor was controlled at 6.0-7.0 with HCl, the COD removal efficiency increased from 50 to 80% over a period of six months, and as a result, the COD of the final effluent fell in the range of 1,000-1,500 mg/L. BOD removal efficiency over the same period was above 90%, and 300 to 400 mg/L was maintained in the final effluent. The average SS in the final effluent was 270 mg/L. The methane production was 0.32㎥ CH$_4$/kg COD(sub)removed and methane content of the methanogenic reactor was high value at 80-90%. When the pH of the acidogenic reactor was not controlled over the final two months, the pH reached 8.2 and acid conversion decreased compared with that of pH controlled, while COD removal was similar to the pH controlled operation. Without pH control, the methane content in the gas from methanogenic reactor improved to 90%, compared to 80% with pH control.

• Asian-Australasian Journal of Animal Sciences
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• 제9권1호
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• pp.75-81
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• 1996

The dry matter (DM) disappearance and ruminal solubility of calcium (Ca), phosphorus (P), magnesium (Mg) and potassium (K) in eight Philippine forages were studied. The forages were: paragrass (Brachiaria mutica (Forsk.) Stapf), stargrass (Cynodon plectostachyum Pilger), napiergrass (Pennisetum purpureum Schumach), clopo (Calopogonium mucconoides Desv.), centrocema (Centrocema pubescens Benth.), gliricidia (Gliricidia sepium (Jacq.) Walp.), leucaena (Leucaena leucocephala (Lam.) de Wit.) and sesbania (Sesbania grandiflora (L.) Poir. Nylon bags with samples were incubated for 0, 3, 6, 12, 24, 48 and 72 h in rumen cannulated sheep. The 0-h bags were washed with deionized water. For the 0-h samples, 20.4, 17.2, 50.7, 52.2 and 80.1% of the DM, Ca, P, Mg and K was solubilized, respectively. At 3-h incubation period, DM disappearance was 10 percentage units higher than that of 0-h incubation whereas mineral disappearance increased by 43, 21, 30 and 13% for Ca, P, Mg and K, respectively. At 72-h incubation period, greater proportion of DM, Ca, especially in P, Mg and K was solubilized with a value of 73.8, 71.5, 85.6, 91.4 and 98.2%, respectively. The average particulate passage rate obtained in the present study was 1.9%/h where as the range of disappearance rates of various mineral elements were : 0.4 to 1.2%/h for Ca, 0.1 to 1.6%/h for P, 0.7 to 2%/h for Mg and 0.1 to 2%/h for K. The effective ruminal solubilization (ERS) of the macrominerals was calculated where particulate passage rate and disappearance rate of the various elements were included in the equation. The ERS of Ca, P, Mg and K was 50.0, 72.6, 83.9 and 94.5%, respectively. Species differences (p<0.05) on the various mineral solubilities were also observed. This study shows that ruminal solubility of macrominerals in selected Philippine forages is K > Mg > P > Ca.

• 대한환경공학회지
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• 제39권3호
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• pp.105-111
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• 2017

본 연구는 낙동강 하류원수를 정수처리하는 정수장에서 전염소 처리시 pH 조절, 오존처리, 응집이 THMs 생성에 미치는 영향을 평가하기 위해 수행하였다. 원수의 pH를 낮추면 전염소 처리에 의해 THMs 생성이 저감되었다. pH를 9.5에서 9.0로 낮추면 THMs 생성이 18.3%, 9.0에서 8.0으로 낮추면 14%, 8.0에서 7.0으로 낮추면 7%, 9.5에서 8.0으로 낮추면 29% 감소되었다. 염소처리 전에 저농도의 오존($0.11{\sim}0.48mg{\cdot}O_3/DOC$)을 주입하면 오존을 주입하지 않은 경우에 비해 THMs 생성을 6~24% 정도 저감시킬 수 있었다. 전오존 1.0 mg/L을 주입한 원수에 염소 2.5 mg/L를 주입하고 alum 40 mg/L, 황산 6 mg/L를 주입한 경우 THMs 생성농도가 염소만 처리한 경우에 비해 42% 감소하였다. 정수처리공정에서 전오존 처리 후에 염소를 투입하고 응집이나, pH 조절을 하면 취수구에서 pH만 낮추는 경우에 비해 THMs 제어에 더 효과적이다. 염소 2.5 mg/L를 주입한 후 alume 40 mg/L 주입하여 응집실험을 한 결과, THMs 생성농도가 염소만 투입한 경우에 비해 pH 저하로 인해 19%, 천연 유기물질(NOM)의 제거로 18% 정도 저감되었다. 응집은 pH 저하와 유기물 제거를 동시에 유발하기 때문에 pH를 낮추는 경우에 비해 THMs 생성농도 저감에 효과적이었다.