• Korean Journal of Materials Research
• /
• v.3 no.6
• /
• pp.614-623
• /
• 1993

Electrical characteristics of LiF-$Li_{2}O-B_{2}O_{3}-P_{2}O_5$ glasses with fixed $Li_2O$ content have been investigated by using AC impedance spectroscopy. Part of the total lithium ions present in these glasses contributes to conduction, and the changes in electrical conductivity with composition was inconsistent with the weak electrolyte model. The power law could not be used to determine the hopping ion concentration in these glasses. Both mobile carrier density and mobility have been modified as Li were added in the form of LiF. The formation of $(B-O-P)^-,di^-$, and metaborate group gave additional available sites for Li+ diffusion causing the enhancement of conductivity. The observed maximum conductivity was $2.43 \times 10^{-4}$S/cm at $150^{\circ}C$ at the composition containing 8mol% LiF. The decomposion potential amounted to 5.94V. The Li/glass electrolyte/$TiS_2$ solid-state cell showed open circuit voltage of 3.14V and energy density of 22 Wh/Kg at $150^{\circ}C$.

• Journal of the Korean GEO-environmental Society
• /
• v.18 no.12
• /
• pp.25-36
• /
• 2017

This research was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage (AMD) by multi-functional zeolite-slag ceramics (ZS ceramics), in which natural zeolite and converter slag were mixed and calcined at high temperature. The batch test showed that the removal efficiency of heavy metals by pellet-type ZS ceramics increased as the mixing weight ratio of converter slag to natural zeolite increased. The optimal mixing ratio of natural zeolite to converter slag for the removal of heavy metals and sulfate ion from AMD was observed to be 1:2~1:3. The adequate calcination temperature and time of ZS ceramics for the treatment of AMD were found to be $600{\sim}800^{\circ}C$ and 2 hours, respectively. The removal test of heavy metals and sulfate ion from AMD by the ZS ceramics prepared in optimal condition exhibited very high removal efficiencies close to 100% for all heavy metals (Al, As, Cd, Cu, Fe, Mn, Pb, Zn) and 77.1% for sulfate ion. The experimental results in this study revealed that the ZS ceramics could function as an effective agent for the treatment of AMD.

• Journal of the Korean Chemical Society
• /
• v.49 no.6
• /
• pp.560-566
• /
• 2005

Sintered ceramic samples of pure and some copper doped layered sodium lithium tri-titanate ($Na_{1.9}Li_{0.1}Ti_{3-X}Cu_XO_{7-X}$) materials with different dopant molar percentages (0.0$Cu^{2+}$ at $Ti^{4+}$ sites in the lattice is proposed in this paper. Furthermore, three distinct regions have been identified in log(${\sigma}_{d.c.}T$) versus 1000/T plots. The lowest temperature region is attributed to electronic hopping conduction(polaron) for all copper doped derivatives and ionic conduction for lithium substituted $Na_2Ti_3O_7$.The mechanism of conduction in the intermediate region is associated interlayer ionic conduction and in the highest temperature region is associated modified interlayer ionic conduction.

• Membrane Journal
• /
• v.10 no.2
• /
• pp.92-101
• /
• 2000

For selective elimination of salt in the boiled extract of baby neck clam (Tapes variegata, BEBNC), electrodialyzer was used and the desalination conditions of BEBNC were determined at various concentrations, pH's and volumes of BEBNC. The ion-exchange membrane with a molecular weight cut off 100 Da was used for desalting of BEBNC. The desalination times on BEBNC concentrations of 0.5％ and 4％ were 100 min and 170 min and the final desalting ratio was above 90％. 1'he desalination of BEBNC at pH 4.0 was 12％ higher than that at pH 9.0 for 60 min. The electrodialysis process could remove above 90％ of the initial salt content in 2％ BEBNC of 1 L for 80 min. The results obtained prove that electrodialysis is a practical solution to the problem of selective elimination of salt from BEBNC.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.48.1-48.1
• /
• 2010

Mono-crystalline silicon solar cell is fabricated by using alkali metals. These alkali metal, used in wet etching process, must be removed for the high efficiency solar cell. As wet etching process has been adapted due to its low cost. But lots of alkali metals like potassium remains on the silicon surface and acts as impurities. To remove these alkali metals many of cleaning process have to be applied when solar cell manufacturing process. In terms of alkali metal removal, modified etchant solution is required for concise cleaning process. In this paper ethylenediamine was used and proposed for the substituion of postassium hydroxide.

• Analytical Science and Technology
• /
• v.6 no.3
• /
• pp.247-254
• /
• 1993

Strontium can not be determined by conventional dc polarography method since it is very difficult to be reduced at the drop mercury electrode(DME) in aqueous solution. However the analytical sensitivity was improved by adsorptive stripping voltammetry in which electro-reduction of ligand in a complex formed between strontium and o-cresolphthaleoxone was performed. Strontium could be determined in range of $5{\sim}30{\mu}g/L$ concentration. This method was affected by coexistent alkali earth metal ions. Consequently ion exchange separation is recommended to analyze strontium in samples.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.509-509
• /
• 2013

유기발광소자는 빠른 응답속도, 높은 색재현성 및 높은 명암비의 장점을 가지며 차세대 디스플레이로서 소형 및 대형 디스플레이로 각광 받고 있다. 저전압구동 유기발광소자를 제작하기 위해 p-i-n 유기발광소자에 대한 연구가 진행되고 있다. 그러나 p형 물질에 대한 연구는 많이 진행 되었으나 n형 유기물질에 대한 연구는 아직까지 진행되고 있지 않다. n형 무기물질로 알칼리 금속을 많이 사용하고 있지만, 공기 중에 쉽게 산화되고 금속 이온의 확산에 의한 발광층 여기자 소멸 효과에 의한 효율 감소문제가 있다. 또한, 무기물질의 높은 증착온도에 따른 유기층의 손상 문제가 있다. 이러한 문제점을 해결하기 위해 유기물 n형 물질에 관한 연구가 필요하다. 본 연구에서는 n형 유기물 도펀트인 bis (ethylenedithio)-tetrahiafulene (BEDT-TTF)를 4,7-diphenyl-1,10-phenanthroline (BPhen) 전자수송층에 도핑하여 유기발광소자의 전자 수송 능력을 향상하였다. BEDT-TTF의 낮은 증착온도와 공기 중에 산화가 되지 않으며, 유기물을 사용하기 때문에 발광층 여기자 소멸을 방지할 수 있다. 전자수송층에 도핑된 BEDT-TTF 분자는 산화 반응에 의한 전자 증가에 따른 에너지 장벽을 감소시켜 전자의 주입을 향상하였다. BEDT-TTF의 농도에 따른 유기발광소자의 광학적 및 전기적 특성을 각각 관찰하여 BEDT-TTF의 농도에 따른 전자 수송 향상에 따른 저전압 유기발광소자 구동을 관측하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2012.03a
• /
• pp.61-61
• /
• 2012

현재 기능성 의류 섬유시장에서도, 요구하는 주요 기능들의 퍼포먼스 수준을 보여주는 과학적 수치들과 함께 기능성 섬유제작 과정에서 얼마나 친환경적인 제조과정을 거쳤는가에 대한 정보들도 요구하고 있는 중이다. 섬유에 인간과 환경에 유해한 성분이 최대한 배제됐으며 생산 과정에서의 자연자원의 낭비가 이뤄지지 않았음을 증명해야한다. CPB 전처리 공정은 혼방직물과 같이 서로 다른 물성을 가지는 직물에 대한 저온 처리로 섬유 손상을 최소화하고, $CO_2$ 발생량 및 에너지 소비량을 감소시킬 수 있는 이점이 있다. CPB 전처리는 호발, 정련, 표백을 포함하는 공정으로 일욕으로 처리 시 패딩, 수세, 와인딩 공정을 단축시키기 때문에 약품 소비량 감소와 에너지 사용 절감 효과가 있어 전 세계적으로 확산되고 있는 Green Technology이다. 본 연구에서는 CPB용 전처리 조제(4~5종)을 일욕화 하여 가공업체 생산성 향상 및 원가절감, 환경유해성 감소를 목표로 하여 CPB 전처리의 최적 가공조건을 확립하는 것이 목표이다. 첨가 용제의 종류 및 첨가량을 변화시켜 각 조성비에 따른 sample을 제조하여 정련성, 호발성, 알칼리 안정성, Whiteness를 측정하여 전처리 성능을 분석하고, 과수안정성, 금속이온 봉쇄력을 비교하여 최적 조성비 및 중합조건을 확립하였다.

• Analytical Science and Technology
• /
• v.7 no.3
• /
• pp.253-260
• /
• 1994

Analytical characteristics of low power-low flow inductively coupled plasma-atomic emission spectometry(ICP-AES) has been studied. Although the net intensity of the low power ICP is lower than the moderate power ICP, the signal to background ratio becomes higher since the background intensity decreases with decreasing the RF power. The detection limit of the low power ICP is comparable with that of the moderate power ICP. The dynamic range of the calibration curve of the low power ICP is $10^4{\sim}10^5$. The ionization interferences by alkali metals increase with increasing the carrier gas flow rate, but the effects are not varied significantly with the RF power.

• Journal of the Korean Chemical Society
• /
• v.30 no.3
• /
• pp.327-332
• /
• 1986

Spatial (radial and height) distribution of electron number density is measured for an inductively coupled plasma under five operating conditions: (1) no carrier gas, (2) carrier gas without aerosel, (3) carrier gas with aerosol, (4) carrier gas with desolvated aerosol, and (5) carrier gas with aerosol and excess lithium. A complete RF power mapping of electron density is obtained. The plasma electrons for a typical analytical torch are observed to be hollow at the radial center in the region close to the induction coil, but diffuse rapidly toward the center in the higher region of the plasma. The presence of excess Li makes no significant change in the electron density profiles. The increases in the RF power levels increase the values of electron density uniformly across the radial coordinate.