• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.279-282
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• 1997

The propose of this study is research and improvement of LiNiO$_2$as cathode material for Lithium secondary batteries. LiNiO$_2$is prepared by heating LiOH . $H_2O$ and Ni(OH)$_2$(mole ratio 1 : 1) on various heat condition. In the result of XRD mesurement, all LiNiO$_2$prepared at this study showed hexagonal structure. In Cyclic Voltammetry, LiNiO$_2$is not conspicous about oxidation peak but oxidation curve change steeply over 3.8V and reduction peak discover at 3.6V. In discharge capacities, specific capacity is higher $O_2$than air when preliminary heated and 75$0^{\circ}C$ than $700^{\circ}C$, 80$0^{\circ}C$ when heated. Therefore, when preliminary heat at $650^{\circ}C$ $O_2$and heat at 75$0^{\circ}C$ carried out, discharge property is the best.

• 자원환경지질
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• 제41권2호
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• pp.183-199
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• 2008

본 연구에서는 구룡광산에 적치된 광미층으로 부터 채취된 대표 비교란 코어시료를 대상으로 체계적인 물리 화학적 및 광물학적 특성을 심도별로 정량적으로 파악, 중금속 거동 핵심 영향요소를 기준으로 광미층 수직분대를 시도하고, 이를 기초로 광미층 비포화대-포화대에 걸친 원소 거동과 지화학적 조건과의 상관모델을 제시하고자 한다. 구룡광산의 대상 광미층은 화학적으로 지하수면을 경계로 상부층 구간에서의 낮은 pH(4)와 20wt.% 이상의 높은 $Fe_2O_3$ 및 $SO_3$ 함량에 의해 특징지어진다. 물리 화학적 및 광물학적 분석 자료를 고려하여 구룡광산 광미층을 심도증가에 따라 복토층, jarosite zone, Fe-sulfate zone, Fe-oxyhydroxide zone, gypsum-bearing pyrite zone, calcite-bearing pyrite zone, soil zone(광미층 집적 이전 토양층), weathered zone 등 7개분대로 구분할 수 있으며, 새로 생성된 이차광물상의 특성을 고려할 때 지하수면을 기준으로 상부층을 산화대(oxidation zone)로, 하부층을 비산화대(unoxidation zone), 혹은 carbonate-rich primary zone으로 크게 대분할 수 있다. 본 연구결과를 기초로 구룡광산 광미층의 물리 화학적 및 광물학적 변화를 지하수면 상부층에서의 황화광물, 특히 황철석의 산화반응이 핵심요소가 되어, 이로 인한 pH 값의 감소, 일차광물의 용해반응 및 원소 용출, 이차광물상 생성, 그리고 생성된 산의 탄산염 및 규산염광물에 의한 산-중화반응 등 일련의 지화학적 반응으로 설명할 수 있다.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1144-1148
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• 2002

We prepared the polyaniline (Pani) film and powder by chemical polymerization and doping with different dopants and also investigated the capability of Li//polyaniline cells after assembling. The oxidation/reduction potentials and electrochemical reaction of Li//polyaniline cells were tested by cyclic voltammetry technique. The Li//Pani-HCl cells with 10% and 20% conductors show a little larger specific discharge capacities than that without conductor. The highest discharge capacity of almost 50 mAh/g at 100th cycle is also achieved. However, Li//Pani-LiPF6 with 20% conductor shows a remarkable performance of ~90 mAh/g at 100th cycle. This is feasible value for using as the positive electrode material of lithium ion secondary batteries. It is also proved that the powder type electrode of Pani is better to use than the film type one to improve the specific discharge capacity and its stability with cycle.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.339-342
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• 2000

Polypyrrole(PPy) nanotubules were formed within template pores by chemical synthesis using $FeCl_3$ as an oxidant. The oxidation peak of PPy nanotubules in the cyclic voltammogram was observed at about 2.8V and 3.3V vs. $Li/Li^+$, while in the case of PPy film, that was observed at about 3.0V. It suggests that the electron hopping on the main chain of PPy nanotubules was improved. When the PPy nanotubules was used to a cathode of lithium secondary battery, we obtained discharge capacity as much as 27 mAh/g, and initial coulomb efficiency by 90%. We expect that the capacity can be improved by further study.

• Bulletin of the Korean Chemical Society
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• 제13권1호
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• pp.80-83
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• 1992

The secondary nitrogen donors of the Ni(II) complexes of macrotricyclic ligands 8-methyl-1,3,6,8,10,13,15-heptaazatricyclo $[13.1.1.1^{13,15}]$octadecane (A) and 1,3,6,9,11,14-hexaazatricyclo $[12.2.1.1^{6,9}]$octadecane (B) are N-alkylated and the Ni(II) complexes of $N-Me_2A,\;N-Et_2A,\;and\;N-Me_2B$ are obtained. The Ni(II) complexes of $N-Me_2A\;and\;N-Et_2A$ are stable in acidic aqueous solutions while that of $N-Me_2B$ decomposes relatively rapidly. The N-alkylation leads to the decrease in the ligand field strength as well as an anodic shift in both of the oxidation and the reduction potentials of the Ni(II) complexes.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.56-59
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• 2000

In this paper, we have made a comparison between secondary ion mass spectroscopy(SIMS) data by the 5kcV-15keV boron implantation and computer simulation results. In order to make electrical activation of implanted carriers, thermal annealing are carried out by RTP method for 30s at 1000$^{\circ}C$ Two dimensional doping concentration distribution from different mask dimensions under inert gas annealing, dry-, and wet-oxidation condition were calculated and simulated with microtec simulator.

• Tribology and Lubricants
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• 제11권5호
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• pp.1-9
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• 1995

The mechanism of various spherical particles formation from wide range of tribo-systerns is suggested and deduced by the action of micro-explosion on the basis of the thermally-activated wear theory, in which the flash temperature at contact could be reached clearly upto the material molten temperature due to the secondary activation energy from the exothermic reactions involving lubricant thermo-decomposition, metals oxidation, hydrogen reactions and other possible complex thermo-reactions at the contacts. Various shapes of spherical particles generated from the tribosystem can be explained by the toroidal action of micro-explosion accompanied with the complex thermo-chemical reactions at the contact surfaces or sub-surfaces.

• 약학회지
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• 제27권2호
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• pp.181-184
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• 1983

DMSO-oxalyl chloride at low temperature in methylene chloride reacted with isolated secondary hydroxyl groups in some monosaccharides to give alkoxysulfonium salts, convertible to carbonyls in high yields upon addition of triethylamine. And 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-allofuranose which is the key intermediate in the synthesis of 3-O-acetyl-5-O-benzoyl- 2-deoxy-2- fluoro-D-arabinofuranosyl bromide, was also obtained by oxidizing 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-glucofuranose with the oxidizing reagent, followed by reduction with sodium borohydride.

• 한국진공학회지
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• 제10권2호
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• pp.225-233
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• 2001

Oxygen flooding을 이용한 Secondary ion Mass Spectrometry(SIMS) 분석에 있어서 표면에 산화막이 있을 때 발생하는 SIMS depth profile의 왜곡현상에 대한 원인을 분석하고 이를 보정하였다. 이러한 왜곡현상은 표면 산화막에서와 Si 매질에서의 sputter rate이 다른 데서 발생하는 깊이 보정 오류와 상대감도인자(relative sensitivity factor, RSF)가 다른 데서 발생하는 농도보정 오류로부터 발생됨이 밝혀졌다. 깊이보정 오류를 바로잡기 위하여 $N^a+$ 이온을 산화막과 Si 매질의 계면에 대한 marker로 사용하였으며 산화막 두께는 SEM 및 XPS로 측정하였다. 산화막과 Si 매질에서의 sputter rate 및 RSF의 차이는 주로 oxygen flooding이 유발한 산화막 형성시의 부피팽창에 의한 것으로 해석되었으며 이를 보정한 depth profile은 oxygen flooding없이 분석한 경우와 거의 동일한 결과를 보여주었다.

• The Plant Pathology Journal
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• 제26권1호
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• pp.57-62
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• 2010

Low-molecular-weight secondary metabolites from plants play an important role in reproductive processes and in the defense against environmental stresses or pathogens. In the present study, we isolated various volatiles and phenolic compounds from white Rosa rugosa flowers, and evaluated the pharmaceutical activities of these natural products in addition to their ability to increase survival in response to environmental stress and pathogen invasion. The DPPH and hydroxyl radical-mediated oxidation assay revealed that the white rose flower extract (WRFE) strongly scavenged free radicals in a dose dependent manner. Moreover, WRFE inhibited the growth of E. coli and fatally attacked those cells at higher concentration (>0.5 mg/mL). FITC-conjugated Annexin V stain provided further evidence that WRFE had strong antimicrobial activity, which may have resulted from a cooperative synergism between volatiles (e.g. 1-butanol, dodecyl acrylate and cyclododecane) and phenolic compounds (e.g. gallic acid) retained in WRFE. In conclusion, secondary metabolites from white rose flower hold promise as a potential natural source for antimicrobial and non-chemical based antioxidant agents.