• 자원환경지질
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• 제45권1호
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• pp.9-21
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• 2012

본 논문에서는 황사 발원지 (타클라마칸, 알라샨, 오도스 사막 및 황토고원) 토양 시료의 지구화학적 특성을 규명하고, 이들이 지표환경과 인체에 미치는 영향을 알아보고자 하였다. 중국 건조지역에서 채취한 토양 시료 내 주원소 함량의 공간적 변화는 각 지역별로 크지 않았으며, 이는 각 지역 내 토양이 오랜 기간 동안 바람에 의해 균질하게 혼합된 것으로 해석된다. 한편 미량원소의 경우에는, 시료 채취 지점에 따라 미약한 함량의 차이를 나타낸다. 이들 중 Cr, Cu, As, Co, Ni, V, Y, Sc, Sn, Pb, Zn, Cd, Cs, Li, Th, U 등은 원소 간에 서로 양의 상관관계를 보이며, 이들의 특성은 황토고원과 다른 사막 (타클라마칸, 알라샨 및 오도스 사막) 토양에서 뚜렷하게 구분된다. 모든 사막 및 황토고원 토양의 Fe의 지구화학적 존재형태는 대부분 "잔류형 (85% 이상)"으로 나타났으나, Mn 및 Ca의 존재형태는 사막에 따라 존재형태의 차이가 현저하게 나타났다. Mn은 황토고원 토양에서는 "산화철망간광물 수반형 (55.4%)"이, 그리고 타클라마칸 사막에서는 "탄산염광물 수반형 (33.8%)"이 다른 사막 토양에 비해 2-5배 높게 나타났다. 또한 Ca의 경우에는 타클라마칸 및 알라샨 사막 토양에서 "탄산염광물 수반형"이 각각 75.9% 및 50.5%로 높게 나타났으나, 황토고원 (6.6%)과 오도스 사막 (2.1%)에서는 낮게 나타났다. 사막 및 황토고원 내 미량원소의 이동도를 기준으로 이들 미량원소를 5개의 그룹으로 분류하였으며, Cd, Pb 및 Cu의 이동도가 각각 87%, 33% 및 30% 이상으로 나타났다. 따라서 사막 및 황토고원 내 Cd, Pb 및 Cu는 지표수 등과 반응하였을 때 쉽게 용해되어 지표환경 및 인체 건강에 악영향을 줄 가능성이 있음을 지시하고 있다.

• 대한환경공학회지
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• 제32권1호
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• pp.23-32
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• 2010

정체수역에서는 자연적 흐름의 차단으로 인해 자정능력이 떨어지며, 영양염류의 축적으로 인해 부영양화와 같은 문제점이 발생한다. 또한 비점오염물질의 유입은 정체수역 내 난분해성 물질을 증가시킨다. 본 연구에서는 정체수역의 수질개선을 위해 무산소조, 호기1조, 호기2조로 구성된 장치형 상향류 활성탄 생물막 반응기를 도입하여 정체수의 연속적 순환에 따른 오염물질 농도의 변화를 모니터링 하였다. 정체수역을 모사하기 위하여 $2m^3$의 저장탱크에 유원지의 호소수를 저장하였으며, 수질개선을 위한 최적 유입 유량을 산출하기 위하여 HRT가 6 hr, 4 hr, 2 hr 가 되도록 호소수의 유입 유량을 변화시켰다. 이 가운데 HRT 4 hr에서 SS, $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, TN, TP의 제거 효율이 각각 69.8, 83.0, 91.3, 74.1, 74.7, 88.9%로 가장 좋은 수질 개선 효과를 얻을 수 있었다. 이에 HRT를 4 hr로 고정하고 골프장 연못수를 운전했을 때 SS, $BOD_5$, $COD_{Mn}$, $COD_{Cr}$ TN, TP의 제거 효율이 각각 78.5, 78.0, 80.2, 74.9, 55.6, 97.5% 달성되었다. 각 조건에서의 미생물 군집 변화를 PCR-DGGE를 사용하여 분석 결과, 유입수를 골프장 연못수로 교체함에 따라 미생물 군집에 변화가 나타났다. 또한 FISH에 의해 유입 유량 변화에 따른 질산화 미생물량의 변화를 관찰한 결과, HRT 4 hr의 조건에서 질산화 미생물이 가장 우점화됨을 알 수 있었다. 미생물량 및 INT-DHA를 이용한 미생물 활성도 실험 결과, HRT를 낮게 유지하였을 때에도 감소되지 않았다. 따라서 상향류 활성탄 생물막 공정을 정체 수역의 효과적인 수질 개선에 충분히 적용할 수 있을 것으로 기대한다.

• 대한지역사회영양학회지
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• 제16권5호
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• pp.569-579
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• 2011

The purpose of this study was to determine the urinary Ca, P, Mg, Zn, Cu, and Mn levels and bone mineral density (BMD) in sixty-two postmenopausal women. The study was conducted through anthropometric checkup, 24-hour recall, 24-hour urine and bone mineral density using DEXA. Average age, height, weight and body fat of the subjects were respectively 65.39 years, 150.19 cm, 58.03 kg and 37.22%. The average spine and femoral neck BMD of subjects were -2.19, -3.13. The mean intakes of Ca, P and Mg were 524.7 mg, 993.10 mg, and 254.6 mg and those of Zn, Cu and Mn were 8.6 mg, 1.5 mg, and 3.5 mg. The average 24-hour urinary excretion of Ca (UCa), P (UP) and Mg (UMg) were 161.07 mg, 673.68 mg, and 99.87 mg. The average 24-hour urinary excretion of Zn (UZn), Cu (UCu) and Mn (UMn) were 366.50 ${\mu}g$, 22.57 ${\mu}g$, and 1.55 ${\mu}g$. Ca intake showed significantly positive correlations with urinary UCa (p < 0.05), UMg (p < 0.01) and spine BMD (p < 0.05). P intake showed significantly positive correlations with UCa (p < 0.05), UMg (p < 0.05) and UZn (p < 0.05). Mg intake showed significantly positive correlations with UZn (p < 0.05) and Mn intake showed significantly positive correlations with UCa (p < 0.05). Multiple regression analysis indicates that Ca intake and UMg is the most important factor to increase spine BMD. On the other hand, UCa is the most important factor to decrease spine BMD. Higher femoral neck BMD was related to UP, while lower femoral neck BMD was related to UCa. In conclusion, Dietary intake of Ca showed positive effect of spine BMD, while excessive P intake showed negative effect on BMD due to increases in UCa, UMg and UZn. Further studies are required to investigate the relationship between bone metabolism and mineral excretion.

• 환경영향평가
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• 제16권1호
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• pp.69-77
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• 2007

This study has been conducted to assess blackish-water phenomena in Dam reservoir. To searching for the reason, we survey physical changes in reservoir and analyze metal and organic content in particulate materials and water. The blackish-water phenomena in lake A are occurred with turbidity increases in turnover season irregularly. It was reported on 6 Jan. 2005 weakly and the water column mixed with 35~40m depth and water temperature shows $7^{\circ}C$. The turbidity of AD and AM site increased up to 20NTU. Especially, AN site shows 27NTU, such a result makes that Dam manager conclude it to blackish-water phenomena. The results of sequential extraction analysis show that over 80% of Al, Cr and Fe is existed in residual form in sediment. On the other hand, the most part of Mn shows exchangeable and carbonates form, which have a good possibility of release to water column. Mn contents in pore waters of the sediment samples are also found to be ~4 times higher than Fe contents. The metal contents in pore water of different dam sites are in order of AN (Fe: 9.98, Mn: 40.6) > AD(8.33, 37.5) > DD(1.91, 2.55). According to the results of extracted organic materials from sediment, humic substances is occupied with over 85% in total organic carbon including 23~45% of humic acid (HA) and 0.9~8.5% of fulvic acid (FA). However, HA content in pore water is not detectable while FA contents, acid-soluble humic fractions is higher than that of sediment(10~15%). which indicating that FA is a main humic components affecting water color. The color unit per DOC of FA in pore waters of different dam sites are found to be higher in lake A than lake D. From the results, it could be suggested that blackish-water phenomena of lake A are mainly arise from higher concentration of Mn and water soluble organic fractions (e.g., FA) released from sediments as well as the strength of turnover in Dam reservoir.

• 한국식품위생안전성학회지
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• 제30권1호
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• pp.87-91
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• 2015

Eight minerals (Ca, Cu, Fe, K, Mg, Mn, Na and Zn) were determined in Schizandra chinensis fruits and their infusions in Seoul. The average mineral contents per Schizandra chinensis fruits (100 g) were K (966.08 mg), Mg (87.20 mg), Ca (15.19 mg), Mn (6.19 mg), Fe (3.99 mg), Zn (2.78 mg), Na (2.15 mg) and Cu (0.31 mg) respectively by Inductively Coupled Plasma-Mass Spectrometer. The quantity of K and Zn were found significantly higher in Korean fruits than the Chinese fruits (p < 0.05). The other 6 minerals did not reveal remarkable difference. In the case of processed Schizandra chinensis tea, it had K (217 mg), Mg (20.40 mg), Ca (7.16 mg), Na (2.95 mg), Mn (1.34 mg), Fe (0.95 mg), Zn (0.25 mg) and Cu (0.09 mg) per 100 g respectively. In extraction of Schizandra chinensis fruits, as it took a longer extraction time, and in a powder form rather than a raw form, it had a higher contents of minerals. When a powder type of Schizandra chinensis fruits was extracted for 24 hours at $25^{\circ}C$, the transfer rate appeared with Ca (36.27%), Mn (25.44%), K (22.43%), Zn (21.00%), Na (19.91%), Mg (19.55%) Cu (13.78%) and Fe (6.45%) respectively.

• 대한치과교정학회지
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• 제32권1호통권90호
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• pp.1-7
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• 2002

개방교합 경향을 갖고 있으나 보상작용 등에 의해 전치부 개방교합을 보이지 않는 성인 여성환자들의 보상양태를 관찰하여 진단 및 치료계획 수립에 도움을 주고자 본 연구를 시행하였다. 피개교합 심도지수(ODI)가 66이하이며 전치부 개방교합을 나타내는 증례(50명)를 대조군으로, 피개교합 심도지수(ODI)가 66이하이나 보상작용에 의하여 전치부 개방교합을 보이지 않는 증례(55명)를 실험군으로 하였다. 대조군과 실험군의 평균연령은 각각 23.88 ${\pm}$ 4.53세와 24.7 ${\pm}$ 6.20세이었다. 측모두부방사선 사진을 촬영하였으며 두 군간의 형태학적 차이를 비교하기 위해 41개 항목에 대한계측 및 통계학적인 분석을 시행하였다. 계측항목 중 lower face height, N-Me, ANS-Me, ANS-Me/N-Me ratio, Mx1-SN, Mx1-FH, Mx1-NA(mm), Mx1-APo, PP to Mx6, Mn1-NB(degree), Mn1-NB(mm)에서 통계학적인 유의차가 나타났다. 실험군에서는 감소된 lower face height N-Me, ANS-Me, ANS-Me/N-Me ratio와 상하악전치의 설측 경사 및 후퇴, 대조군에서는 상악 구치의 과맹출이 관찰되었다.

• 한국전기전자재료학회논문지
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• 제20권9호
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• pp.756-760
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• 2007

Flame retardant(FR) properties were investigated with tricredyl phosphate(TCP) and tris(pentafluorophenyl)phosphine(TFPP) as additives for lithium-ion batteries. Thermal stability was improved with additives in $Li/LiNi\frac{1}{3}Mn\frac{1}{3}Co\frac{1}{3}O_2$ cells comparing to non-additive electrolytes. Oxygen evolution reaction of the cathode material was delayed to up $55^{\circ}C$, from $275^{\circ}C\;to\;330^{\circ}C$. Electrolytes with the 1 wt.% additives provided good FR properties while the resonable battery performance is maintained.

• 한국세라믹학회지
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• 제29권12호
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• pp.970-980
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• 1992

${\gamma}-alumina$ membranes were prepared by sol-gel dip coating or pressurized coating of boehmite sols on slipcasted ${\gamma}-alumina$ support tubes. The particle size of sols synthesized via the modified Yoldas-method could be controlled below 5 mn according to the mole ratio of nitric acid/aluminumtri-sec-butoxide (0.07~1.0). The reproducible crack-free composite membranes were produced by the 2nd dip coating or the pressurized coating technique using very stable sols with the particle size of 45 nm. Nitrogen gas permeability through the top-layer in the composite membrane was about $70~55{\times}10^{-7}\;mol/m^2{\cdot}s{\cdot}Pa$. The thermal stability of the top layer was proved to be good enough upto the heat-treatment temperature of $500^{\circ}C$.

• 미생물학회지
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• 제20권3호
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• pp.105-112
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• 1982

The strain of Aspergillus, 6368A, producing acid protease showing high activity was isolated from soil, as a result of wide research about mold group. This strain was identified as a species of Aspergillus tubingensis by the investigation of morphological characteristics. The change of the enzyme production under the various media and culture condition was also studied. The optimum pH and stability of crude acid protease are 2.5, 2.0~4.5 and the optimum temeprature and thermal inactivation waas shown $50^{\circ}C,\;55^{\circ}C$, respectively. From the result of the study on the effects of metal ions, it was found that $MnCl_2,\;CoCl_2,\;CuCl_2,\;SrCl_2,\;and\;NiCl_2$ slightly increased the enzyme activity, on the other hand $ZnCl_2,\;CaCl_2,\;MgCl_2,\;SLS,\;and\;KMnO_4$ decreased it.

• 미생물학회지
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• 제18권1호
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• pp.7-14
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• 1980

A thermostrable ${\beta}-galactosidase$ (${\beta}-galactoside$ galactohydorlase, EC 3.2.1.23) was inducible in Bacillus coagulans by lactose and D-glactose. The enzyme was purified 87 fold, and the optimum temeprature and pH for actiivity were determined to be $60^{\circ}C$ and pH 7.5, respectively. Kinetic determinations at $55^{\circ}C$ established a Km of 3.3mM for the chromogenic substrate onitorphenyl ${\beta}-D-galactopyranoside$ (ONPG). Galactose and lactose were competitive inhibitors with Ki of 6.1mM and 4.9mM, respectively. The enzyme ws relatively thermostable. The crude enzyme was inactivated about 20% after 20 min of exposure at $60^{\circ}C$ and the purified was about 50%. Maximal enzyme activity required $Mn^{++}$, and for the thermal stabilization $Fe^{++}\;and\;Ca^{++}$ were necessary.