• Title/Summary/Keyword: Fe^{3+}$

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Comparison of Nutrient Content and Retention Rate among Chuichung Cucumber, White Dadagi Cucumber, and Yellowish Overripe Cucumber according to Different Cooking Methods (취청오이, 백다다기오이, 노각의 조리방법에 따른 영양 성분 및 잔존율 연구)

  • Kim, Honggyun;Chung, Heajung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.11
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    • pp.1350-1357
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    • 2017
  • General component and mineral contents according to species of Capsicum annuum were investigated. In addition, chuichung cucumber, white dadagi cucumber, and yellowish overripe cucumber were cooked by using seven different methods (boiling, steaming, pan-cooking, roasting, pan-frying, deep-frying, and microwaving), and retention rates of general components and minerals according to species were evaluated. Weight loss was observed in all cucumber species using all cooking methods. Most general component and mineral contents of C. annuum samples were significantly different according to species, and cooking method (P<0.05), whereas Fe and Cu contents were not significantly affected by species and cooking method, respectively. As a result, the highest protein, fat, ash contents were detected in deep-fried C. annuum, and high moisture contents were detected in raw, boiled, and steamed C. annuum. High mineral contents were detected in roasted and microwaved chuichung cucumber, deep-fried white dadagi cucumber and yellowish overripe cucumber. Retention rates of C. annuum by cooking method, ranged from 30~100% for protein, 10~100% for fat, 35~90% for moisture, and 30~100% for ash. High retention rates were observed for minerals in boiled, roasted, and microwaved chuichung cucumber, and deep-fried white dadagi cucumber and yellowish overripe cucumber. However, in yellowish overripe cucumber, mineral retentions rate were remarkably lowered by boiling and steaming, resulting in rates of 20~45%. These results were the data used as the basis for development of cucumbers.

Reinforcement Mining Method for Anomaly Detection and Misuse Detection using Post-processing and Training Method (이상탐지(Anomaly Detection) 및 오용탐지(Misuse Detection) 분석의 정확도 향상을 위한 개선된 데이터마이닝 방법 연구)

  • Choi Yun-Jeong;Park Seung-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06b
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    • pp.238-240
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    • 2006
  • 네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc

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Antioxidative and Cellular Protective Effects of Dolwoe (Gynostemma pentaphyllum Makino) Extracts against Oxidative Stress (돌외(Gynostemma pentaphyllum Makino) 추출물의 산화적 스트레스에 대한 항산화 및 세포보호효과)

  • Kim, Kyoung Mi;Kim, A-Rang;Kim, A-Young;Ha, Ji Hun;Xuan, Song Hua;Jeong, Yoon Ju;Park, Young Min;Jeong, Hyo Jin;Hong, In Gi;Park, Soo Nam
    • Korean Journal of Pharmacognosy
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    • v.48 no.2
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    • pp.125-133
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    • 2017
  • In this study, we investigated the total phenolic and flavonoid contents, component analysis, antioxidative activity and cellular protective effects against oxidative stress on human skin cells in 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Gynostemma pentaphyllum (G. pentaphyllum) Makino. The DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activites ($FSC_{50}$) of the 50% ethanol extracts, ethyl acetate fraction and aglycone fraction were 246.8, 147.2, $128.9{\mu}g/mL$, respectively. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the 50% ethanol extract, ethyl acetate fraction and aglycone fraction on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay were 37.15, 10.74, $7.19{\mu}g/mL$, respectively. We investigated the cellular protective activity and the results showed that treatment of aglycone fraction ($0.05-0.39{\mu}g/mL$) protect human skin cells in a concentration-dependent manner when the skin cell damages were induced by treating them with $H_2O_2$. These results suggest that extract/fractions of G. pentaphyllum Makino may be applicable as natural antioxidants in cosmetics.

플라스틱 기판상에 저온 증착된 IZO박막의 특성 연구

  • Jeong, Jae-Hye;Jeong, Yu-Jeong;Yun, Jeong-Heum;Lee, Seong-Hun;Lee, Geon-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.455-455
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    • 2010
  • 차세대 디스플레이로 널리 알려져 있는 플렉서블 디스플레이는 휴대하기 쉽고, 깨지지 않으며, 변형이 자유로워 현재 우리 사회에 크게 주목받고 있다. 플렉서블 디스플레이의 구현을 위해서는 기존의 유리 기반 디스플레이 소자 기술에 더하여 플렉서블 기판소재에 적용 가능한 투명전도막 기술의 확립이 필요하다. 디스플레이 산업에서 주로 사용되는 투명전도막은 ITO (indium tin oxide) 및 IZO (indium zinc oxide)와 같은 투명전도성 산화물 박막 (TCO, transparent conducting oxide)이다. 그런데 플라스틱 기판이 굽힘 환경에 놓이게 되면 그 위에 증착된 산화물 박막이 쉽게 파손될 수 있다. 따라서 플렉서블 디스플레이 기술에 있어서 변형에 따른 TCO 박막의 파괴 거동에 대한 연구가 필수적이다. 본 연구에서는 PET (polyethylene terephthalate) 기판 상에 증착된 IZO 박막의 반복 굽힘 시 계면구조 변화에 따른 파괴거동을 조사하였다. 플라스틱 기판의 사용을 위해서는 산소 및 수분의 투과 방지막이 필요하며 본 연구에서는 투과 방지막 (또는 보호막)으로서 $SiO_x$ 박막을 적용하였다. IZO 박막은 $In_2O_3$ - 10 wt% ZnO 타겟을 사용하여 RF magnetron sputtering법으로 $100^{\circ}C$ 미만에서 저온 증착하였다. 보호막으로 사용되는 $SiO_x$ 박막은 HMDSO (hexamethyldisiloxane)와 Ar 및 $O_2$ 혼합기체를 이용하는 PECVD 방법으로 합성하였다. 변형에 따른 TCO 박막의 파괴 거동을 조사하기 위하여 반복 굽힘 시험 (cyclic- bending test)을 실시하였다. 반복 굽힘 시험 중 실시간으로 IZO 박막의 전기저항 변화를 측정하여 박막의 파괴 거동을 모니터링 하였다. 시편 A (135 nm-thick IZO/PET), B (135 nm-thick IZO/ 90 nm-thick $SiO_x$/PET), C (135nm-thick IZO/ 300 nm-thick $SiO_x$/PET)에 대하여 곡지름 35mm, 1000회 반복 굽힘을 실시하여 변형 중의 전기저항 변화를 조사하였다. 그리고 굽힘 시험 완료 후, FE-SEM을 이용한 시편 표면형상 관찰을 통하여 균열생성 정도를 관찰하였다. 반복 굽힘 시험 결과, A 와 C 시편의 경우, 각각 반복 굽힘 20회, 550회에서 급격한 전기저항의 증가가 관찰되었다. 그러나 B 시편의 경우, 1000회 반복 굽힘 후에도 전기저항의 변화는 나타나지 않았다. 이와 같이 반복 굽힘에 의한 IZO 박막의 파괴 거동 변화는 IZO 박막과 기판의 계면구조변화에 기인한 것으로 해석된다. IZO 박막과 기판의 계면에 $SiO_x$ 층을 삽입함으로써 계면 접합강도가 향상되었을 것으로 추측된다. 따라서 변형에 대한 파괴 저항 특성이 우수한 투명전도성 산화물 박막의 형성을 위해서는 적절한 계면구조 제어를 통한 계면 접합 특성의 향상이 필요하다.

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Terahertz Generation and Detection Using InGaAs/InAlAs Multi Quantum Well

  • Park, Dong-U;Han, Im-Sik;No, Sam-Gyu;Ji, Yeong-Bin;O, Seung-Jae;Seo, Jin-Seok;Jeon, Tae-In;Kim, Jin-Su;Kim, Jong-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.205-205
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    • 2013
  • 테라헤르쯔(terahertz: THz)파는 0.1~10 THz 의 범위로 적외선과 방송파 사이에 광대역 주파수 스펙트럼을 차지하고 있으며 직진성, 투과성, 그리고 낮은 에너지 (meV)를 가지고 있어 비 파괴적이고 무해한 장점을 지니고 있다. Ti:sapphire laser와 같은 femto-pulse source 등이 많은 발전이 되어 현재 많은 연구와 발전이 이루어지고 있다. femto-pulse source를 이용한 THz 응용에서는 높은 저항, 큰 전자 이동도, 그리고 아주 짧은 전하수명의 기판을 요구하는데 저온에서 성장한 (low-temperature grown : LT) GaAs는 격자 내에 Gallium 자리에 Arsenic이 치환 하면서 AsGa antisite가 발생하여 전하수명을 짧아지는 것을 응용하여 가장 많이 이용되고 있다. 현재 THz 응용분야에서 보다 작고 가격경쟁력이 있는 광통신을 이용한 THz photomixer등이 활발히 연구 하고 있다. 광섬유 내에서 손실과 분산이 최소값을 가지는 부분이 1.55 ${\mu}m$ 부근이고 In0.53Ga0.47As 기판을 이용하였을 때 여기에 완벽하게 만족하게 된다. 하지만 LT-InGaAs 의 경우 AsGa antisite로 인하여 carrier lifetime은 짧아지지만 높은 n-type 전하밀도를 가지게 된다. 이때 Be을 doping하여 전하밀도를 보상하여 높은 저항을 유지해야 하는데 Be의 활성화를 위해서는 열처리를 필요로 한다. 하지만 열처리를 하면 carrier lifetime이 길어지기 때문에 carrier lifetime과 저항을 적절히 조율해야 한다. 이는 물질자체의 특성이기 때문에 InGaAs는 GaAs보다 낮은 amplitude와 짧은 cut-off frequency를 가진다. 본 연구에서는 보다 높은 저항을 얻기 위하여 molecular beam epitaxy를 이용하여 semi-insulating InP:Fe 기판위에 격자 정합된 InGaAs:Be/InAlAs multi quantum well (MQW)를 온도별 ($250{\sim}400^{\circ}C$), 주기별 (50~150)로 성장을 하였고 이때 InGaAs layer의 Be doping level은 $2{\times}1018\;cm^{-3}$, Ex-situ annealing은 $550^{\circ}C$에서 10분으로 고정 하였다. THz 발생 실험에서는 InGaAs/InAlAs MQW은 4000 pA로 1,000 pA를 가지는 InGaAs epilayer보다 4배 높은 전류 신호를 얻을 수 있었고 모든 샘플이 2 THz에서 cut-off frequency를 가지고 있었다. THz 검출 실험에서는 LT-InGaAs:Be epilayer LT-InGaAs:Be/InAlAs, HT-InGaAs/InAlAs 샘플이 각각 180, 9000, 12000 pA의 전류신호를 가지고 있었고 모든 샘플이 2 THz에서 cut-off frequency를 가지고 있었다. HT-InGaAs/InAlAs MQW를 이용한 검출실험에서는 InGaAs layer가 defect free이지만 LT-InGaAs:Be/ InAlAs MQW 보다 높은 전류 신호를 얻을 수 있었다. 이는 InAlAs layer가 저항만 높이는 것뿐만 아니라 carrier trapping layer로써의 역할도 하는 것으로 사료된다.

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A Study on the Standardization In Diagnostic Criteria on Jung-Pung (中風) (중풍진단(中風診斷)의 표준화방안(標準化方案) 연구(硏究))

  • Shim, Hyun-Ki;Park, Se-Ki;Kim, Dong-Woo;Jun, Chan-Young;Han, Yang-Hee;Park, Jong-Hyeong
    • The Journal of Internal Korean Medicine
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    • v.18 no.2
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    • pp.332-357
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    • 1997
  • The purpose of study is for the defining the diagnostic criteria of Jung-Pung (中風) which are confused or unclear partially or Oriental Medicine. The results were obstained as follows ; 1. The Diagnosis of Jung-Pung (中風) can be accomplished by the name of disease, symptomatic classification, Byun-Jeung (辨證), stage, assessment of neurological deficit. 2. The various expressive way on the names of Jung-Pung (中風) can be unified as Jung-Pung (中風). 3. The symptomatic classification of Jung-Pung (中風) can be Jung-Kyung-Rak (中經絡) and Jung-Jang-Bu (中臟腑) by unconsciousness. 4. The subclassification of Jung-Kyung-Rak(中經絡) is Kanyangpokhang Punghwa sangyo (肝陽暴亢 風火上擾證), PungDamErHyul BiJoMaecRak (風痰瘀血 痺阻脈絡證), DamYeolBusil PoongDamSangYo (痰熱腑實 風痰上擾證), KiHerhyulEr (氣虛血瘀證), YeumHer PungDong (陰虛風動證) and Jung-Jang-Bu (中臟腑) is PungHwa SangYo CheongGeu (風火上擾淸竅證), DamSeupMongSac ShimSin (痰濕蒙塞心神證), DamYeolNaeFe ShimGeu (痰熱內閉心竅證), WonKiFaeTal ShimSinChakRan(元氣敗脫心神錯亂證) 5. The classification of stages can be divided as stroke stage, convalescent stage, complicated deficit stage. 6. In Oriental Medicine there were few assessment methods of neurological deficit. Therefore we need to develop new assessment system or modification of Western Medicine. The Standardization in the diagnosis of Jung-Pung (中風) has not been well established, even though we had have many clinical experiences. So it is necessary to make a accurate diagnosis that can be done by multiple diagnostic assessment. Therefore the accurate diagnosis of Jung-Pung (中風) can be done by 5 factors, they are the name of diagnosis, symptomatic classification, Byun-Jeung (辨證), stage, the assessment of neurological dificit. And it can be applied in the planning of treatment.

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Sulfate Reduction in the Marine Environments: Its Controlling Factors and Relative Significance in Mineralization of Organic Matter (해양환경의 황산염 환원율 조절요인 및 유기물 분해에 있어 황산염 환원의 중요성)

  • 현정호;이홍금;권개경
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.2
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    • pp.210-224
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    • 2003
  • Sulfate reduction is a microbiological process which occurs ubiquitously in anaerobic marine environment. Sulfate reducing bacteria play a significant role in anaerobic decomposition of organic matter and regeneration of inorganic nutrients which supports the primary production in the water column (i.e., benthic-pelagic coupling) and, in special case, could be responsible for the harmful algal bloom in the coastal marine environment. Summary of the sulfate reduction rates reported in various marine sedimentary environments revealed that supply of organic substrates and presence of various electron acceptors (i.e., $O_2$, NO$_{3}$$^{[-10]}$ , Fe(III) and Mn(IV), etc.) for other aerobic and anaerobic respiration directly affect the sulfate reduction rate and relative significance of sulfate reduction in organic matter mineralization. Significance of temperature, macrophytes and bioturbation is discussed as factors controlling supply of organic substrates and distribution of electron acceptors. Finally, we suggest studies on the anaerobic microbiological processes associated with biogeochemical element cycles in the coastal environments of Korea where massive operation of organic enriched fish cage farm, frequent occurrence of toxic algal bloom and hypoxia and conservation of tidal flat are of major environmental issues.

Some Factors Affecting Bone Mineral Density of Korean Rural Women (농촌 성인 여성들의 골밀도에 영향을 미치는 요인 분석 연구)

  • 이정숙
    • Journal of Nutrition and Health
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    • v.32 no.8
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    • pp.935-945
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    • 1999
  • The factors affecting bone mineral density (BMD) of 103 rural women aged 30 to 76 years were investigated. Data for food and nutrient intake was obtained by 24-hour recall method. BMD of lumbar spine(L1-L4), femoral neck, ward's triangle and trochanter was measured by XR-series x-ray bone densitometer. Serum was collected and analyzed for total Ca, P and ionized Ca (Ca++)content. Relationship between the factors and BMDs was analyzed by Pearson's correlation coefficient(r) and multiple regression analysis. The results are summarized as follows. 50% of the subjects under 50 years of age($\leq$49 yr group) and 86.4% of the subjects from 50 up($\geq$50yr group) were classified as osteopenia or osteoporosis. Mean body weight, height and BMI were 153.1cm, 59.1kg and 25.0kg/$m^2$ in $\leq$49 yr group and 151.9cm, 55.9kg, and 24.2kg/$m^2$ in $\geq$50 yr group. BMDs of lumbar spines and femurs ranged from 0.84 to 1.05g/$m^2$ and from 0.67 to 1.16g/$m^2$ in $\leq$49 yr group, and ranged from 0.67 to 0.85kg/$m^2$ and from 0.68 to 0.44g/$m^2$ in $\geq$50 yr group, respectively. On the whole, the BMDs were reduced to 83.8 to 94.2% of peck bone mass in $\leq$49 yr group and 55.2 to 78.9% of those in $\geq$50 yr group. Mean daily intake of Ca was much less than the Korean RDA, \67.2% in $\leq$49 yr group and 62.3% in $\geq$50 yr group. The average concentration of total Ca, P and Ca++ in serum were within normal range in both age group. Both age and height were significantly related with BMD in both age group but the relationship tended to be stronger in $\geq$50 yr group than in $\leq$49 yr group. Body weight was also a potent determinant of BMD only in 50 yr group. In $\leq$49 yr group, total food intake was positively related with BMDs of ward's triangle, L1 and L2 and intake of cereals and grain products, sugars and sweets, milk and dairy products was positively related with BMDs measured in this study. On the contrary, intake of eggs, oil and fats were positively related with a few BMDs in 50 yr group. The BMDs were positively affected by intake of energy, protein, carbohydrate, Ca, P and Fe in $\leq$49 yr group and those of protein, fat Ca, P, vitamin B1, vitamin B2 and vitamin C in $\geq$50 yr group. It was noteworthy that serum Ca++ concentration was positively related with BMDs of lumbar spine in boty age groups. According to multiple regression analysis, the four factors, age, body weight, height and BMI additionally accounted for 21% of the variance in BMD of trochanter in $\leq$49 yr group and only two factors, age and C a intake accounted for 38% of that of femoral neck in $\geq$50 yr group. Further investigation is necessary to make sure of the relations between BMD and serum Ca++ level.

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Evaluations of Si based ternary anode materials by using RF/DC magnetron sputtering for lithium ion batteries

  • Hwang, Chang-Muk;Park, Jong-Wan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.302-303
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    • 2010
  • Generally, the high energy lithium ion batteries depend intimately on the high capacity of electrode materials. For anode materials, the capacity of commercial graphite is unlike to increase much further due to its lower theoretical capacity of 372 mAhg-1. To improve upon graphite-based negative electrode materials for Li-ion rechargeable batteries, alternative anode materials with higher capacity are needed. Therefore, some metal anodes with high theoretic capacity, such as Si, Sn, Ge, Al, and Sb have been studied extensively. This work focuses on ternary Si-M1-M2 composite system, where M1 is Ge that alloys with Li, which has good cyclability and high specific capacity and M2 is Mo that does not alloy with Li. The Si shows the highest gravimetric capacity (up to 4000mAhg-1 for Li21Si5). Although Si is the most promising of the next generation anodes, it undergoes a large volume change during lithium insertion and extraction. It results in pulverization of the Si and loss of electrical contact between the Si and the current collector during the lithiation and delithiation. Thus, its capacity fades rapidly during cycling. Si thin film is more resistant to fracture than bulk Si because the film is firmly attached to the substrate. Thus, Si film could achieve good cycleability as well as high capacity. To improve the cycle performance of Si, Suzuki et al. prepared two components active (Si)-active(Sn, like Ge) elements film by vacuum deposition, where Sn particles dispersed homogeneously in the Si matrix. This film showed excellent rate capability than pure Si thin film. In this work, second element, Ge shows also high capacity (about 2500mAhg-1 for Li21Ge5) and has good cyclability although it undergoes a large volume change likewise Si. But only Ge does not use the anode due to its costs. Therefore, the electrode should be consisted of moderately Ge contents. Third element, Mo is an element that does not alloys with Li such as Co, Cr, Fe, Mn, Ni, V, Zr. In our previous research work, we have fabricated Si-Mo (active-inactive elements) composite negative electrodes by using RF/DC magnetron sputtering method. The electrodes showed excellent cycle characteristics. The Mo-silicide (inert matrix) dispersed homogeneously in the Si matrix and prevents the active material from aggregating. However, the thicker film than $3\;{\mu}m$ with high Mo contents showed poor cycling performance, which was attributed to the internal stress related to thickness. In order to deal with the large volume expansion of Si anode, great efforts were paid on material design. One of the effective ways is to find suitably three-elements (Si-Ge-Mo) contents. In this study, the Si based composites of 45~65 Si at.% and 23~43 Ge at.%, and 12~32 Mo at.% are evaluated the electrochemical characteristics and cycle performances as an anode. Results from six different compositions of Si-Ge-Mo are presented compared to only the Si and Ge negative electrodes.

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Characteristics of Coastal Water Quality after Diatom Blooms Due to Freshwater Inflow (담수유입에 의한 식물플랑크톤의 대량번식 후의 연안 수질변동 특성)

  • Lee Young-Sik;Park Young-Tae;Kim Kui-Young;Choi Yong-Kyu;Lee Pil-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.2 s.25
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    • pp.75-79
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    • 2006
  • In order to study the characteristics of water quality in coastal water and mechanism of phytoplankton blooms, factors of water quality were investigated in diatom bloom area due to rainfall event and no diatom bloom area Diatom blooms occurred after heavy rain and the dominant species were Skeletonema costatum($1,200{\sim}5,000cells/mL$) and Thalassiosira spp.($750{\sim}1,200cells/mL$). In diatom bloom area, water temperature, pH, and dissolved oxygen were observed at higher level than in no diatom bloom area Although these two areas were only 20 meters apart from each other, sharp difference in coastal water quality between two areas was observed. In diatom bloom area, concentrations of nitrogen, phosphorus, and silicate were observed at lower level than in no diatom blooms area. This seems to be due to inflow of much trace metal such as Fe, Mo, Se and so on than nitrogen, phosphorus, and silicate by rainfall events. However, distinct differences in DIN/DIP and $DIN/SiO_2-Si$ between these two areas were not observed.

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