• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.129-136
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• 2005

원자력 발전소의 증기발생기 슬러지 중에서는 이온교환수지가 발견되어서는 안 된다. 증기발생기 슬러지 시료 중에서 발견되어 이온교환수지 입자로 의심되는 구형 입자들의 특성을 측정하였다. 미세조작기술을 이용하여 광학현미경으로 입자 크기 분포를, EPMA로 구형입자의 성분을, 그리고 IR 분광 스펙트럼 비교에 의하여 이온교환수지 여부를 조사하였다. 슬러지의 입자 크기는 1내지 200 ${\mu}m$이었으나 구형입자는 40-500 ${\mu}m$이었으며, 슬러지의 주요 불순원소가 Si, Al, Mn, Cr, Ni, Zn, 그리고 Ti이었으나 구형입자는 Si, Cu, Zn 이었다. 주성분은 두 경우 모두 철이었으며, IR 분광스펙트럼을 S/G 시스템에서 사용하는 이온교환수지의 경우와 비교했을 때 서로 다른 결과를 보였다. 이 결과들은 것은 증기발생기 슬러지 시료 중에서 발견된 구형 입자가 이온교환수지는 아니며 일반적인 슬러지가 생성되는 과정에서 작은 슬러지 입자들이 크게 뭉쳐서 생성된 것임을 나타내고 있다.

• 생명과학회지
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• 제25권10호
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• pp.1169-1175
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• 2015

본 연구에서는 야생화로부터 채밀한 제주 지역 벌꿀 및 벌집채꿀의 페놀성분 분석과 항산화 활성 비교평가를 시행하였다. 총 폴리페놀 및 플라보노이드 함량 측정 결과 물을 용매로 사용한 벌집채꿀에서 가장 높은 함량을 나타냈다. 또한 벌꿀 및 벌집채꿀 모두 농도 의존적으로 항산화 활성이 증가하는 양상을 보였으며, 이를 EC₅₀ 및 EC_0.5 값으로 환산한 결과 벌집채꿀이 벌꿀에 비해 통계적으로 유의하게 높은 항산화 활성을 나타내었다. 상기의 결과를 종합하여 봤을 때 총 폴리페놀 및 플라보노이드 함량과 항산화 활성간의 높은 연관성이 있다는 것을 추측 해볼 수 있었고 이를 상관관계를 통해 분석한 결과, 총 페놀 및 플라보노이드 성분의 함량과 항산화 활성이 통계적으로 유의한 상관관계를 나타냄을 확인할 수 있었다. 이러한 결과들은 잠재적 천연식품소재로의 벌집채꿀의 가능성을 시사하며 향후 이에 대한 체계적인 연구가 필요하다 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권3호
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• pp.631-635
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• 2001

The major problems associated with the manufacturing processes of the microaccelerometer based on the tunneling current concept is the residual stress. This paper deals with finite element analysis of residual stress causing pop up phenomenon which are induced in micromachining processes for a microaccelerometers sensor using silicon on insulator(SOI) wafer. After heating the tunnel gap up to $100^{\circ}C$and get it through cooling process and the additional beam up to $80^{\circ}C$get it through the cooling process. We learn the residual stress of each shape and compare the results with each other, after heating the tunnel gap up to $400^{\circ}Cduring$ the Pt deposition process. The equivalent stresses produced during the heating process of focused ion beam(FIB) cut was also to be about $0.02~0.25Pa/^{\circ}C$and cooling process the gradient of residual stresses of about $8.4\{times}10^2Pa/{\mu}m$ still at cantilever beam and connected part of paddle. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer sensors.

• 한국표면공학회지
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• 제33권2호
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• pp.126-134
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• 2000

This study investigated the bath compositions and plating conditions and crystal structure used for achieving nickel-thallium-phosphorus deposits by means electroless plating. The electroless nickel-thallium-phosphorus deposits were achieved with a bath using sodium hypophosphite as the reducing agent and sodium citrate as the complexing agent. The depositing rate was 10.5mg.$cm^{2-1}$ .$hr^{-1 }$ from the optimistic bath composition, 0.1M nickel sulfate, 0.005M thallium sulfate, 0.2M sodium hypophosphite, and 0.05M sodium citrat and the recommended plating conditions, pH 5.5 and $90^{\circ}C$. The composition of alloy deposits determined by X-ray analysis (EDS) that the Thallium was increased with major increasing concentration of complexing agent and thallium ion in bath solution, it decreased according to the increasing concentrations of reduction agent in the bath solution, Bit Phosphorus showed a contrary to the thallium. It was observed from X-ray diffraction analysis, Scanning Electron Microscopy and Transmission Electron Microscopy. The crystalline structure of deposits was amorphous at the first deposited state but it was changed $Ni-T1-Ni_{5}$ $P_2$ polycrystalline when subjected to 1 hour heat treatment of more than $350^{\circ}C$. TEM observation demonstrated that the microstructure was identical to the result of the XRD at as deposited but it became $Ni-Tl-Ni_{5}$ $P_2$ polycrystalline when heated. And grain size was 10-50nm.

• Computers and Concrete
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• 제21권4호
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• pp.471-484
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• 2018

Refined analysis depicting mass transportation and physicochemical reaction and reasonable computing load with acceptable DOFs are the two major challenges of numerical simulation for concrete durability. Mesoscopic numerical simulation for chloride diffusion considering binder, aggregate and interfacial transition zone is unable to be expended to the full structure due to huge number of DOFs. In this paper, a multiscale approach of combining both mesoscopic model including full-graded aggregate and equivalent macroscopic model was introduced. An equivalent conversion of chloride content at the Interfacial Transition Layer (ITL) connecting both models was considered. Feasibility and relative error were discussed by analytical deduction and numerical simulation. Case study clearly showed that larger analysis model in multiscale model expanded the diffusion space of chloride ion and decreased chloride content in front of rebar. Difference for single-scale simulation and multiscale approach was observed. Finally, this paper addressed some worth-noting conclusions about the chloride distribution and rebar corrosion regarding the configuration of rebar placement, rebar diameter, concrete cover and exposure period.

• 대한지역사회영양학회지
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• 제3권4호
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• pp.630-641
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• 1998

As the incidence of diet-related diseases increase, much attention has been focused of traditional foods. Traditional foods are ultimately based on local foods. However, there has been little study looking into the recipes and nutritional value of local foods. Therefore, the present study was designed to standardize recipes and analyze the nutrients of some representative local foods of Cheollabuk-do Province. Their foods were Cheonju pibimpap, kongnamulgukpap, minmuljangokui, aejeotchim and aguytichim. Test recipes for each food were prepared, being based on various information obtained from personal interviews, literature surveys of restaurant recipes. Then test recepe was subjected to sensory evaluation. All characteristics of each food were judged as "satisfactory". The analysis of nutrient composition revealed that in general energy content was low whereas protein content was as high as recommended reguirement in all foods except for kongnamulgukpap. Vitamin content was generally high but contents of calcium and iron were relatively low in all foods. Cheonju pibimpap was rich in dietary fiber. Dietary fiber content of Cheonju pibimpap was 16.6g per serving size. All foods contained considerable amounts of essential amino acids. The major fatty acide were oleic acid, linoleic acid and glutamic acid, oleic acid being the highest in terms of composition ratio.ion ratio.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.712-718
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• 2004

This study was carried out to separate the calcium-binding protein derived from enzymatic hydrolysates of cheese whey protein. CWPs (cheese whey protein) heated for 10 min at $100^{\circ}C$ were hydrolyzed by trypsin, papain W-40, protease S, neutrase 1.5 and pepsin, and then properties of hydrolysates, separation of calcium-binding protein and analysis of calcium-binding ability were investigated. The DH (degree of hydrolysis) and NPN (non protein nitrogen) of heated-CWP hydrolysates by commercial enzymes were higher in trypsin than those of other commercial enzymes. In the result of SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), $\beta$-LG and $\alpha$-LA in trypsin hydrolysates were almost eliminated and the molecular weight of peptides derived from trypsin hydrolysates were smaller than 7 kDa. In the RP-HPLC (reverse phase HPLC) analysis, $\alpha$-LA was mostly eliminated, but $\beta$-LG was not affected by heat treatment and the RP-HPLC patterns of trypsin hydrolysates were similar to those of SDS-PAGE. In ion exchange chromatography, trypsin hydrolysates were shown to peak from 0.25 M NaCl and 0.5 M NaCl, and calcium-binding ability is associated with the large peak, which was eluted at a 0.25 M NaCl gradient concentration. Based on the results of this experiment, heated-CWP hydrolysates by trypsin were shown to have calcium-binding ability.

• Bulletin of the Korean Chemical Society
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• 제24권3호
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• pp.363-368
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• 2003

The major ionic components of precipitation collected at the 1100 Site of Mt. Halla and Jeju city have been determined. The reliability of the analytical data was verified by the comparison of ion balances, electric conductivities and acid fractions; all of their correlation coefficients were above 0.94. Ionic strengths lower than $10^{-4}$ M were found in 53% of the 1100 Site samples and 28% of the Jeju city samples. Compared with other inland areas, the wet deposition of $Na^+,\;Cl^-\;and\;Mg^{2+}$ was relatively larger, but that of $NH_4^+,\;nss-SO_4^{2-}$(non-sea salt sulfate) and $NO_3^-$ was lower. Especially the wet deposition increase of $Ca^{2+}$ in the spring season supports the possibility of the Asian Dust effect. The acidification of precipitation was caused mostly by $SO_4^{2-}\;and\;NO_3^-$ in the Jeju area, and the organic acids have contributed only about 7% to the acidity. The neutralization factors by NH₃were 0.47 and 0.48, and that of CaCO₃was 0.31 and 0.25 at the 1100 Site and Jeju city, respectively. Investigation into major influencing sources on precipitation components by factor analysis showed that the precipitation at the 1100 Site had been influenced mostly by an anthropogenic source, followed by soil and seawater sources. The precipitation at Jeju city was mainly influenced by oceanic sources, followed by anthropogenic and soil sources.

• 한국지반환경공학회 논문집
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• 제9권4호
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• pp.47-52
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• 2008

본 연구는 안동지역에 소재하는 안동 임하호 저니토가 호소수에 미치는 영향을 조사하기 위하여 안동호와 임하호 6개 지역에서 채취한 저니토의 토양성분과 중금속 용출 특성을 분석하였다. 대부분의 저니토는 illite(I), kaolinite(Ka), quartz(Q) 및 feldspar(F)로 구성되어 있다. 저니토에 포함된 중금속 중 아연(Zn), 비소(As), 크롬(Cr), 구리(Cu), 납(Pb)의 농도는 임하호에 비하여 안동호에서 상대적으로 높게 나타났다. 특히 안동호의 저니토에서는 다른 중금속들에 비해 비소(As)와 아연(Zn)의 용출이 크게 나타났다. 저니토를 이용한 흡착실험에서는 아연(Zn), 카드늄(Cd) 및 구리(Cu)의 흡착은 적게 일어난 반면 납(Pb)과 크롬(Cr)은 높은 흡착력을 보여주었다.

• 자원환경지질
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• 제56권2호
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• pp.125-138
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• 2023

수계 내 세슘(cesium: Cs)을 제거하기 위하여 개발된 대부분의 기존 Cs 흡착제들은 원재료 값이 고가라는 단점과, 해수와 같이 높은 이온 강도와 낮은 Cs 농도를 가지는 대규모의 오염수를 실질적으로 정화하는데 한계를 가지고 있었다. 본 연구에서는 석탄광산배수를 처리하는 과정에서 생성되는 슬러지(CMDS)에 Na와 S를 첨가하여 친환경적이고 높은 Cs 제거 효율을 가지는 Cs 흡착제를 개발하였다. Fe 및 Ca 함량이 풍부한 CMDS를 1차 소재로 사용하였고, 열처리 과정으로 Na와 S를 첨가하여 새로운 Cs 흡착제를 제조하였다(이하 본 연구에서 개발한 흡착제는 Na-S-CMDS라 명명함). Na-S-CMDS의 Cs 흡착능 및 흡착 기작을 평가하기 위해 실험실 규모의 실험과 흡착 동역학 및 등온 모델링 연구를 수행하였으며, XRF, XRD, SEM/EDS, XPS 등의 분석을 통해 Na-S-CMDS의 물리화학적, 광물학적 특성을 조사함으로써 Cs 흡착 기작을 규명하였다. 흡착 배치 실험 결과, Cs은 빠르게 Na-S-CMDS에 흡착되어 1시간 내 평형에 도달하였으며, 낮은 Cs 농도(0.5 mg/L) 조건에서도 높은 Cs 제거 효율(> 90.0%)을 보였다. 흡착 등온 모델링 결과, 단일 흡착을 가정하는 Langmuir 흡착 등온 모델에 대응되는 경향을 보였으며, 흡착 동역학 모델링 결과 흡착 경향이 유사 2차 속도(pseudo second order kinetic) 모델과 일치하는 경향을 보였고, 이러한 결과는 단순한 물리적 흡착보다 이온 교환과 같은 화학적 흡착이 우세함을 의미한다. 고농도의 Cs 용액으로 반응시킨 Na-S-CMDS의 XRF/XRD 분석 결과, Na-S-CMDS 내 Na 함량은 감소하고 흡착 전 존재하던 erdite (NaFeS₂·2(H₂O))가 관찰되지 않는 것을 통해, Na⁺과 Cs⁺ 사이에서 활발한 이온 교환 반응이 진행되었음을 알 수 있었다. XPS 분석 결과, Na-S-CMDS에서 Cs와 S 사이의 강한 결합 작용이 관찰되었으며, 이러한 Cs와 S(또는 S-복합체)내 결합에너지 감소도 Na-S-CMDS의 Cs 흡착능을 증가시키는 요인으로 판단되었다. 본 연구를 통해 기존에 폐기물로 처리되었던 석탄광산배수슬러지를 개량하여 제조한 Na-S-CMDS는 기존의 Cs 흡착제보다 제조 비용이 저렴하고, 해수 및 지하수와 같이 이온 강도는 높지만 Cs 농도가 낮은 대규모 오염 수계에서도 Cs 흡착능이 높게 유지되어, 현장에서 효과적인 Cs 흡착제로 사용할 수 있을 것으로 기대한다.