• 한국지반환경공학회 논문집
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• 제12권7호
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• pp.39-47
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• 2011

본 연구에서는 red mud를 흡착제로 이용하여 산성광산배수내 대표적인 유해 중금속인 Cd과 Pb의 흡착특성을 파악하고, 산처리와 소성처리 방식으로 활성화된 red mud에 의한 Cd와 Pb의 중금속 흡착능의 변화를 알아보고자 하였다. Red mud에 대한 Cd과 Pb의 흡착은 반응시간 30분 이내에 대부분 발생하였으며, 5시간 경과 후에는 평형상태에 도달하는 것으로 나타났다. pH가 증가할수록 red mud에 대한 Cd 및 Pb의 흡착은 증가하는 것으로 나타났다. Red mud를 증류수 혹은 산으로 중화 처리하거나 산처리 혹은 소성처리 등과 같은 활성화 처리할 경우 Cd와 Pb에 대한 red mud의 흡착능은 오히려 감소하는 것으로 나타났으므로 red mud를 이용한 Cd와 Pb의 흡착제거는 가공하지 않은 원 상태의 red mud를 이용하는 것이 효과적인 것으로 파악되었다. Red mud에 대한 Cd와 Pb의 흡착거동은 Langmuir 및 Freundlich 등온흡착모델에 모두 잘 적용되었으며, Red mud 흡착제에 대한 Langmuir 등온 흡착식의 $q_m$ 과 Freundlich 등온흡착식의 $K_F$ 상수값은 Cd에 대하여 각각 5.230mg/g와 1.118mg/g이었으며 Pb에 대해서는 각각 22.222mg/g와 7.241mg/g의 값을 나타내고 있었다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2004년도 동계학술연구발표회 논문개요집
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• pp.38-39
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• 2004

• 과학과기술
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• 제34권8호통권387호
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• pp.36-39
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• 2001

초고속 인터넷 대중화 시대, 국내 가입자 6백만명 넘어/새로운 국면에 접어든 위성통신 이리듐/개발자 지원으로 시장 확대를 노린다/가상 CD-ROM 드라이브로 간편하게/손쉽게 구축하는 인터넷 쇼핑몰

• 과학과기술
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• 제35권5호통권396호
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• pp.36-39
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• 2002

[Information Technology의 세계] 일회용 DVD와 CD/[Bio Technology의 세계] 탄수화물은 바이오산업의 시작이다/[Nano Technology의 세계] 원자현미경은 미래 과학의 견인차/[Environmental Technology의 세계] 물절약 대책 시급하다

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.171-178
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• 1991

The two-stage enzyme reactor, packed with cyclodextrin glucanotransferase (CGTase) immobilized on Amberite IRA 900, coupled with ultrafiltration membrane was investigated for continuous production of cyclodextrin (CD). 5% (w/v) of soluble starch was partially cyclized, in the 0.1 l first-stage immobilized enzyme reactor, up to CD conversion yield of 10% (w/w) at retention time of 0.56hr and 1.5 units of immobilized CGTase/1g of carrier. In the second stage main immobilized enzyme reactor capacity of 1.5 l, the maximum CD conversion yield of 39% (w/v) was achieved at retention time of 2.8hr and 0.47 unit of CGTase/1 g of carrier. Unreacted residual dextrin was fractionated with ultrafiltration membrane, and then, recycled into the second-stage main bioreactor to increase the CD conversion yield. The most suitable membrane size and the volume concentration ratio (concentrate: filterate) for recycling of unreacted residual dextrin were found to be 5K dalton and 4:6, respectively. CD conversion yield was increased about 3~4% upon co-immobilization of pulluanase along with CGTase. Spent Amberite IRA 900 can be reutilized consecutively more than 3 times for immobilization of CGTase after regeneration.

• Environmental Engineering Research
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• 제17권3호
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• pp.125-132
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• 2012

The removal of Cd(II) and Cu(II) from aqueous solution by an agricultural solid waste biomass prepared from Moringa oleifera bark (MOB) was investigated. The biosorbent was characterized by Fourier transform infrared spectroscopy and elemental analysis. Furthermore, the effect of initial pH, contact time, biosorbent dosage, initial metal ion concentration and temperature on the biosorption of Cd(II) and Cu(II) were studied using the batch sorption technique. Kinetic studies indicated that the biosorption process of the metal ions followed the pseudo-second order model. The biosorption data was analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Based on the Langmuir isotherm, the maximum biosorption capacities for Cd(II) and Cu(II) onto MOB were 39.41 and 36.59 mg/g at 323 K, respectively. The thermodynamic parameters, Gibbs free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$), and entropy (${\Delta}S^o$) changes, were also calculated, and the values indicated that the biosorption process was endothermic, spontaneous and feasible in the temperature range of 303-323 K. It was concluded that MOB powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Cd(II) and Cu(II) ions from aqueous solution.

• Journal of Animal Science and Technology
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• 제45권2호
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• pp.199-210
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• 2003

일반사료, 고콜레스테롤사료 또는 포화지방함량이 높은 사료를 섭취한 흰쥐에서 항혈전작용과 혈액중성지방 및 콜레스테롤 수준에 관한 $\beta$-cyclodextrin($\beta$CD)의 급여효과를 조사하였다. 출혈시간은 일반사료, 고콜레스테롤 및 고지방사료 섭취군 모두에서 $\beta$CD 첨가구가 대조구에 비해서 각각 293%, 157% 및 218% 까지 유의적으로 연장되었다(p<0.05). 전혈응고시간은 일반사료, 고콜레스테롤 및 고지방사료섭취군에서 $\beta$CD 첨가구가 대조구와 비교할때 각각 202%, 168% 및 211%까지 유의적으로 높았다(p<0.05). $\beta$CD 첨가사료는 흰쥐 혈액내 총지질, 중성지방, 총콜레스테롤 및 저밀도지질단백질 콜레스테롤 함량을 현저하게 낮추는 원인이 되었다. 혈액내 총지질 함량은 일반사료, 고콜레스테롤 및 고지방사료 섭취군에서 $\beta$CD첨가구가 대조구에 비해서 각각 70%, 82% 및 87%까지 유의적으로 낮아졌다(p<0.05). 혈액내 중성지방함량은 일반사료, 고콜레스테롤 및 고지방사료 섭취군에서 $\beta$CD 첨가구가 대조구와 비교할 때 각각 89%, 43% 및 59%까지 유의적인 감소를 나타냈다(p<0.05). 혈액내 총콜레스테롤 함량은 일반사료, 고콜레스테롤 및 고지방사료 섭취군에서 $\beta$CD 첨가구가 대조구에 비해서 각각 28%, 62% 및 36%까지 유의적으로 낮아졌다(p<0.05). 혈액내 저밀도 지질단백질 콜레스테롤 함량은 일반사료, 고콜레스테롤 및 고지방사료섭취군에서 $\beta$CD 첨가구가 대조구에 비해서 각각 39%, 54% 및 25%까지 유의적인 감소를 나타냈다(p<0.05). 혈액내 총담즙산 함량은 일반사료, 고콜레스테롤 및 고지방사료섭취군에서 $\beta$CD 첨가구가 대조구에 비해서 각각 66%, 95% 및 97% 까지 유의적인 증가를 보였다(p<0.05). 일반사료 섭취군에서 $\beta$CD 첨가구의 HMG-CoA reductase 활성도는 대조구와 비교할 때 41%까지 유의적으로 낮아졌으며 분을 통한 스테로이드의 배설량은 167%까지 유의적인 증가를 나타냈다(p< 0.05). 이 결과는 $\beta$CD가 사람의 심장혈관계질환과 비만을 예방하는데 도움이 될 수 있는 혈액내 지질, 중성지방 및 콜레스테롤의 감소효과 그리고 항혈전작용에 관한 생리활성 기능을 갖는다는 것을 시사해 주고 있다.

• 한국토양비료학회지
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• 제45권6호
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• pp.900-903
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• 2012

Cadmium is known to be very toxic to human health and can be relative easily translocated from soils in plants. Therefore, a rapid method for screening Cd in soils and crops has become more and more important. For this reason, we examined a rapid immunochromatograpy (ICG) test kit which uses antigen-antibody reaction based on immunoassay and chromatography. Soils and rice grains collected from mine waste-contaminated sites were determined for their Cd contents using this kit. For comparison purposes, 0.1 M HCl and ICP-OES were employed as a conventional extraction and determination method. Cadmium contents in rice grains determined using ICG technique were $0.46{\sim}2.39mg\;kg^{-1}$ and Cd contents determined using 0.1 M HCl and ICP-OES were $0.52{\sim}1.97mg\;kg^{-1}$. The correlation between these two Cd contents were statistically significant ($r^2$=0.930). The results of Cd contents in soils also showed a statistically significant relationship between these two methods ($r^2$=0.975). On the basis of these results, ICG technique can be applied to rapidly quantify Cd in crops and soils. However, further research is necessary to apply ICG technique for the field screening.

• 한국환경보건학회지
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• 제38권4호
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• pp.323-331
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• 2012

Objectives: The objective of this study was to investigate the possible effects of environmental cadmium (Cd) exposure on of bone mineral density (BMD) levels. Methods: A total of 171 residents around abandoned mines in Chungcheongnam-do were surveyed in 2008-2011. Urinary Cd and BMD were analyzed by atomic absorption spectrometry and Dual-Energy X-ray absorptionmetry, respectively. Osteoporosis and osteopenia were defined by T-scores set by the WHO; Tscore ${\geq}$ -1.0, normal; -1.0 > T-score > -2.5, osteopenia; and T-score ${\leq}$ -2.5, osteoporosis. Logistic and multiple linear regressions were applied to estimate the association between U-Cd levels and BMD. Results: The U-Cd geometric mean of 171 Koreans was 2.79 ${\mu}g/g{\cdot}cr$. The U-Cd concentration was significantly higher among women (2.98 ${\mu}g/g{\cdot}cr$) than men (2.39 ${\mu}g/g{\cdot}cr$). With the multiple regression model, the BMD was influenced by U-Cd, BMI, and monthly income. With the logistic regression model, osteoporosis was associated with U-Cd levels (OR = 3.239, 95% CI = 1.770-5.927). Conclusions: We conclude that exposure to cadmium is associated with an increased risk of osteoporosis.

• 대한디지털의료영상학회논문지
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• 제15권1호
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• pp.39-45
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• 2013

PACS Import external image of the thread of the tasks and duties of hospital revenue and business efficiency falls over time. 500 beds or more medical imaging import work outside of the hospital, most hospitals use a PC, KIOSK, and was used in 15 hospitals where, CD Autoloader where use was the only one. Working hours compared to CD and DVD media to test the results of the Import target PC, KIOSK, CD Autoloader Import spent less time in the order, and also the greater capacity of CD Autoloader four times the PC, KIOSK 2 times Import could be implemented quickly. In addition, the waiting time of the patients was measured using the PC's time to Import, 2011 14.5 minutes and the average patient waiting time, KIOSK and later use CD Autoloader 2012 average patient wait time of 8.25 minutes, 43% of the existing average waiting time was 5.25 minutes to reduce. However, KIOSK case of a patient in a way that directly Import latency time was soon. Import of three ways: in terms of efficiency and excellent CD Autoloader way, the patient waiting time in terms of ease of use and KIOSK was excellent. In addition, with the introduction of CD Autoloader with KIOSK Joint of the items waiting time of patients and patient satisfaction rating is considered to be a major contribution.