• 한국식품과학회지
• /
• 제28권5호
• /
• pp.974-980
• /
• 1996

멥쌀로 탁주를 제조하여 발효과정 중에 변화되는 에탄올 및 포도당의 함량을 동시에 측정할 수 있는 바이오센서를 dual cathode electrode를 이용하여 제작하였다. Alcohol oxidase와 glucose oxidase는 nylon net에 고정화시켜 anode가 한 개이고 cathode가 두 개인 dual cathode electrode에 부착하여 용존산소가 소모되는 변화량을 측정하여 간접적으로 포도당과 에탄올의 농도를 동시에 측정할 수 있도록 하였다. 이 시스템의 최적 조건은 $35^{\circ}C$에서 pH 7.5인 0.1 M 인산 완충용액이었다. 바이오센서를 이용하여 측정한 값을 분광광도법과 gas chromatography를 이용한 값과 비교해 본 결과 유사한 것으로 나타났다. Dual cathode electrode를 이용한 바이오센서로 측정할 경우 다른 분석방법과 같은 복잡한 전처리 과정없이 두 가지 성분을 동시에 측정하는 것이 가능함으로써 신속하게 측정할 수 있었으며, 탁주와 같은 발효식품의 발효 중 변화하는 두 가지 성분을 동시에 측정할 수 있었다.

• 한국미생물·생명공학회지
• /
• 제39권4호
• /
• pp.382-386
• /
• 2011

이 연구에서는 일반적인 음극부 한 개에 양극부 한 개로 구성된 single-cathode 미생물연료전지(SCMFC)와 음극부 한 개에 양극부 두 개로 이루어진 dual-cathode 미생물연료전지(DCMFC)를 이용하여 전류발생에 비치는 영향을 확인하였다. 이 결과 dual-cathode 미생물연료전지에서 single-cathode 미생물연료전지 보다 전류발생이 약 40% 높았으며 COD 제거율도 약 13% 더 높은 것으로 확인되었다. 이것은 양극부와 음극부의 접촉면적이 증가하여 양극반응속도가 향상된 것에 의한 것으로 판단되며 dual-cathode 미생물연료전지가 single-cathode보다 전류발생과 COD제거 측면서 더 효율이 높은것으로 나타났다. 음극부 전자수용체에 대한 영향 실험에서는 전자수용체로 사용된 질산성질소의 농도가 높아질수록 급격히 전류발생이 감소하는 것을 확인 할 수 있었으며, 이에 대한 적절한 처리가 필요한 것으로 나타났다.

• 한국표면공학회지
• /
• 제48권4호
• /
• pp.174-178
• /
• 2015

We studied emission characteristics for blue fluorescent dual-side emission OLED with Al cathode thickness variation. In the bottom emission OLED of Al cathode with 10, 15, 20, 25, 30, and 150 nm thickness, maximum luminance showed 36.1, 8,130, 9,300, 12,000, 13,000, and $12,890cd/m^2$, and maximum current efficiency showed 2, 8.8, 10, 10.5, 10.8, and 11.4 cd/A, respectively. The emission characteristics of the bottom emission seemed to be improved according to decrease of resistance as the thickness of Al cathode increase. In the top emission OLED of Al cathode with 10, 15, 20, 25, and 30 nm thickness, maximum luminance showed 4.3, 351, 131, 88.6, and $33.2cd/m^2$, and maximum current efficiency showed 0.23, 0.38, 0.21, 0.16, and 0.09 cd/A, respectively. It yielded the highest maximum luminance and maximum current efficiency in Al cathode thickness 15 nm. It showed a tendency to decrease as the thickness of Al cathode increase. The reason for this is due to decrease of transmittance with increasing of Al cathode thickness. The electroluminescent spectra of bottom and top emission OLED were not change.

• Journal of Electrochemical Science and Technology
• /
• 제13권2호
• /
• pp.269-278
• /
• 2022

Utilization of high-voltage electrolyte additive(s) at a small fraction is a cost-effective strategy for a good solid electrolyte interphase (SEI) formation and performance improvement of a lithium-rich layered oxide-based high-energy lithium-ion cell by avoiding the occurrence of metal-dissolution that is one of the failure modes. To mitigate metal-dissolution, we explored fluorinated dual-additives of fluoroethylene carbonate (FEC) and di(2,2,2-trifluoroethyl)carbonate (DFDEC) for building-up of a good SEI in a 4.7 V full-cell that consists of high-capacity silicon-graphite composite (15 wt% Si/C/CF/C-graphite) anode and Li_1.13Mn_0.463Ni_0.203Co_0.203O₂ (LMNC) cathode. The full-cell including optimum fractions of dual-additives shows increased capacity to 228 mAhg^-1 at 0.2C and improved performance from the one in the base electrolyte. Surface analysis results find that the SEI stabilization of LMNC cathode induced by dual-additives leads to a suppression of soluble Mn²⁺-O formation at cathode surface, mitigating metal-dissolution event and crack formation as well as structural degradation. The SEI and structure of Si/C/CF/C-graphite anode is also stabilized by the effects of dual-additives, contributing to performance improvement. The data give insight into a basic understanding of cathode-electrolyte and anode-electrolyte interfacial processes and cathode-anode interaction that are critical factors affecting full-cell performance.

• 한국분말재료학회지
• /
• 제26권1호
• /
• pp.49-57
• /
• 2019

Layered $LiNi_{0.83}Co_{0.11}Mn_{0.06}O_2$ cathode materials single- and dual-doped by the rare-earth elements Ce and Nd are successfully fabricated by using a coprecipitation-assisted solid-phase method. For comparison purposes, non-doping pristine $LiNi_{0.83}Co_{0.11}Mn_{0.06}O_2$ cathode material is also prepared using the same method. The crystal structure, morphology, and electrochemical performances are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) mapping, and electrochemical techniques. The XRD data demonstrates that all prepared samples maintain a typical ${\alpha}-NaFeO_2$-layered structure with the R-3m space group, and that the doped samples with Ce and/or Nd have lower cation mixing than that of pristine samples without doping. The results of SEM and EDS show that doped elements are uniformly distributed in all samples. The electrochemical performances of all doped samples are better than those of pristine samples without doping. In addition, the Ce/Nd dual-doped cathode material shows the best cycling performance and the least capacity loss. At a 10 C-rate, the electrodes of Ce/Nd dual-doped cathode material exhibit good capacity retention of 72.7, 58.5, and 45.2% after 100, 200, and 300 cycles, respectively, compared to those of pristine samples without doping (24.4, 11.1, and 8.0%).

• 한국미생물·생명공학회지
• /
• 제40권4호
• /
• pp.414-418
• /
• 2012

미생물연료전지 운전을 할 때, 전압손실을 감소시키기 위한 다양한 방법들이 시도 되고 있다. 이 연구는 전해질과 저가의 금속이온을 전자수용체로 이용하여 전류발생을 확인하였다. 전해질로 phosphate buffer를 사용한 경우, 공기만 사용하였을 때보다 향상되었으며, 공기의 공급이 없이는 효과가 적은 것으로 나타났다. 전자수용체로 질산염(nitrate)을 사용하였을 때 산소를 공급하지 않았을 때보다 높은 전류발생을 보였으나 공기포화 물을 사용한 경우와 비교하여 전류발생이 향상되지는 않았다. 질산염을 양극부에 적용시에는 음극부와 양극부 모두 폐수처리가 가능한 시스템으로 구성하여 운전한다면 전류발생은 낮으나 서로 다른 폐수를 처리 할 수 있을 것으로 판단된다. 이 연구에서 적용한 3가지 방법 중에서 3가 철이온을 사용하였을 때 전류 발생이 가장 높았으며, 공기를 공급하지 않아도 전류 발생이 높게 유지되는 것으로 나타났다. 이것은 미생물연료전지의 규모를 증대시킬 때 폭기가 필요 없는 시스템을 구축할 수 있어 큰 장점으로 작용할 것으로 판단된다. 따라서 3가 철이온은 지구상에 가장 많은 금속 이온 중 하나로 용해도가 낮으나 저가의 3가 철이온을 잘 이용한다면 양극부 반응속도를 효율적으로 향상 시킬 수 있을 것으로 판단된다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
• /
• pp.151-154
• /
• 2008

The field emission lamps have the advantages to their cold cathode-characteristic and the eco-friendly, We realized that the dual emitter system showed very simple structure which gate and cathode electrodes are formed on the same glass surface. In this paper, we reported the properties of dual emitters depended on variation of gate width and spacing for optimum panel structure. In combination of dual emitter structure and bi-polar driving, electron beam spreads more than normal gate structure or diode structure, and emission uniformity increased in dual emitter structure at 5"-diagonal.

• 반도체디스플레이기술학회지
• /
• 제7권1호
• /
• pp.47-51
• /
• 2008

The Al:Au double-layer metal electrode for use in transparent, dual emission of organic light-emitting diode (OLED) was fabricated. The electrode of Al:Au metals with various thicknesses was deposited by the vacuum thermal evaporation technique. For Al thickness of 1 nm, a bottom luminance of $4880\;cd/m^2$ was observed at 8 V. Otherwise, top luminance of $2020\;cd/m^2$ were observed at 8 V. In addition, the threshold voltages of the electrodes were 2.2 V. It was forward that the inserting 1 nm Al between LiF and Au enhanced electron injection with tunneling effect.

• Transactions on Electrical and Electronic Materials
• /
• 제1권4호
• /
• pp.16-19
• /
• 2000

Power transistors to be used in Power Integrated Circuits(PIC) are required to have low on resistance, fast switching speed, and high breakdown voltage. The lateral IGBTs(LIGBTs)are promising power devices for high voltage PIC applications, because of its superior device characteristics. In this paper, dual cathode LIGBT(DCIGBT) for high voltage is presented. We have verified the effectiveness of high blocking voltage in the new device by using two dimensional devices simulator. We have analyzed the forward blocking characteristics , the latch up performance and turn off characteristics of the proposed structure. Specially, we have focused forward blocking of LIGBT. The forward blocking voltage of conventional LIGBT and the proposed LIGBT are 120V and 165V, respectively. . The forward blocking characteristics of the proposed LIGBT is better than that of the conventional LIGBT. This forward blocking comparison exhibits a 1.5 times improvement in the proposed LIGBT.

• Journal of Microbiology and Biotechnology
• /
• 제22권2호
• /
• pp.270-273
• /
• 2012

These studies were conducted to determine the effects of various concentrations of ammonium and nitrate on current generation using dual-cathode microbial fuel cells (MFCs). Current generation was not affected by ammonium up to $51.8{\pm}0.0$ mg/l, whereas $103.5{\pm}0.0$ mg/l ammonium chloride reduced the current slightly. On the other hand, when $60.0{\pm}0.0$ and $123.3{\pm}0.1$ mg/l nitrate were supplied, the current was decreased from $10.23{\pm}0.07$ mA to $3.20{\pm}0.24$ and $0.20{\pm}0.01$ mA, respectively. Nitrate did not seem to serve as a fuel for current generation in these studies. At this time, COD and nitrate removal were increased except at $123{\pm}0.1$ mg ${NO_3}^-/l$. These results show that proper management of ammonium and nitrate is very important for increasing the current in a microbial fuel cell.