In order to apply to high-nickel cathodes for high-capacity and stability enhancement of lithium-ion batteries, the characteristics of the coating film were reviewed using the conventional nickel plating method. The surface morphology of the plating layer and the measurement of the surface roughness were analyzed according to scan size and rate using the contact mode of Atomic Force Microscopy. The hydrogen ion concentration (pH) of the electrolyte played an important role in shaping the metal ion plating. As the overpotential of the surface increased during plating, the crystals grew in a direction other than the main crystal growth direction. The increase in on-time during pulse plating appears to result in coarse particles as much of the applied current is consumed by the reduction of hydrogen ions, resulting in lower current efficiency. From the AFM image, it was confirmed that the blackening of the plated film was due to a partial overvoltage phenomenon during electrolytic degreasing. In order to be used as a high-nickel cathode, it seems that the current must be uniformly distributed on the surface of the substrate during plating.

최근 전기자동차용 이차전지 등의 수요가 급증하면서 효율적인 리튬 화합물의 생산이 큰 주목을 받고 있다. 바이 폴라막 전기투석은 친환경적이며 경제성 및 효율성이 우수한 전기화학적 리튬 화합물 생산공정으로 알려져 있다. 바이폴라막 전기투석 공정의 효율은 바이폴라막의 성능에 의해 좌우되기 때문에 바이폴라막의 선택이 매우 중요하다. 본 연구에서는 세 계적으로 가장 널리 사용되고 있는 대표적인 상용 BPM인 Astom사의 BP-1E 및 Fumatech사의 FBM을 비교 분석함으로써 전기화학적 LiOH 생산을 위한 BPED 공정에 적합한 BPM의 특성을 도출하고자 하였다. 체계적인 평가를 통해 BPM의 특성 중 막의 이온전달저항 및 co-ion leakage를 줄이는 것이 가장 중요하고 이러한 관점에서 BP-1E가 FBM보다 더 우수한 성능 을 가지고 있음을 확인하였다.

In this paper, a simulation computerized crash analysis evaluation method through reverse engineering was applied to the Defender vehicle to systemize and simplify the certification of small-scale electric vehicles. The Defender vehicle was selected as a benchmarking vehicle that converts into an electric vehicle, and the layout of the frame and element analysis of individual parts were conducted through reverse engineering. To review the vehicle package layout, the fastening and assembly method for each part was analyzed referring to the Defender maintenance guide and parts list, and it was used for frame element technology analysis. In addition, collisions according to the main frame material and the shape of the crash box were analyzed, and various cases were analyzed through parameter study. As a result of the crash analysis, it was found that the mild steel main frame could not guarantee the safety of the vehicle in a fixed wall collision situation, and the ATOS material would increase the collision safety of the Defender relatively. Through the crash analysis according to the shape of the crash box, it was found that the strength of the crash box is too high compared to the main body, and this should be reflected in the design for small-volume production of multiple products.

We report on the fabrication and characterization of a novel Cu2O/CuO heterojunction structure with CuO nanorods embedded in Cu2O thin film as an efficient photocathode for photoelectrochemical (PEC) solar water splitting. A CuO nanorod array was first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method; then, a Cu2O thin film was electrodeposited onto the CuO nanorod array to form an oxide semiconductor heterostructure. The crystalline phases and morphologies of the heterojunction materials were examined using X-ray diffraction and scanning electron microscopy, as well as Raman scattering. The PEC properties of the fabricated Cu2O/CuO heterojunction photocathode were evaluated by photocurrent conversion efficiency measurements under white light illumination. From the observed PEC current density versus voltage (J-V) behavior, the Cu2O/CuO photocathode was found to exhibit negligible dark current and high photocurrent density, e.g. −1.05 mA/cm2 at −0.6 V vs. Hg/HgCl2 in 1 mM Na2SO4 electrolyte, revealing the effective operation of the oxide heterostructure. The photocurrent conversion efficiency of the Cu2O/CuO photocathode was estimated to be 1.27% at −0.6 V vs. Hg/HgCl2. Moreover, the PEC current density versus time (J-T) profile measured at −0.5 V vs. Hg/HgCl2 on the Cu2O/CuO photocathode indicated a 3-fold increase in the photocurrent density compared to that of a simple Cu2O thin film photocathode. The improved PEC performance was attributed to a certain synergistic effect of the bilayer heterostructure on the light absorption and electron-hole recombination processes.

고온수증기전기분해(HTSE) 장치의 수소생산 및 열 화학적 특성을 파악하고자 COMSOL Multiphysics®를 사용해 2차원 정상상태 수치해석을 실시하였다. 계산을 위한 주요 파라메터로는 작동전압, ASR(Area-specific Resistance) 및 유입가스의 온도와 압력 등이다. 해석결과 1.2454 V에서 Thermal-neutral Voltage가 나타나고, 작동 전압이 증가함에 따라 Cell의 내부 온도가 단조 증가하는 것이 아니라 Thermal-neutral Voltage를 기준으로 낮은 전압에서는 Cell의 온도가 감소하고, 높은 전압에서는 Cell의 온도가 증가하였다. 또한, ASR 값이 증가함에 따라 Cell 내부의 온도는 하강하고, 수소생산율도 낮아지는 경향을 보였다.

이 연구에서는 친환경적이고, 효율적인 수소생산방식으로 알려진 고온수증기전기분해(HTSE)에 대한 열․화학적 특성 및 수소 생산 특성을 파악하고자 하였으며, 이론적 고찰과 더불어 정밀한 전산유체해석(CFD)를 통하여 획득한 결과를 제시하였다. 연구의 주요 파라메터로는 ASR(Area Specific Resistance)의 영향 및 유입가스의 온도와 압력 등이다. 상용 FEM CODE인 COMSOL Multiphysics ver. 3.3 소프트웨어를 이용하여 2차원 정상상태 전산유체해석을 실시하였으며, 다음과 같은 결론을 얻었다. 1) ASR 값이 증가함에 따라 cell 내부의 온도는 하강하였 고, 수소생산율도 낮아졌다. 2) 입구압력이 0.1MPa과 5MPa인 경우를 비교한 결과 0.1MPa일 때가 5MPa일 때 보다 최대속도를 기준으로 약 52 배 빠른 속도를 나타내며, cell의 최대온도를 기준으로 약 6.6K 가량 높은 것으로 확인되었다.

The present study was carried out to develop a cloning technology of mouse embryos by nuclear transplantation with electrofusion and to produce cloned offsprings by transfer of reconstituted embryos. A single nucleus from two- and eight-cell embryos was transplanted into the enucleated two-cell embryos by rnicromanipulation. The fusion of nucleus with recipient cytoplasm and the subsequent development of reconstituted embryos in vitro as well as in vivo to term were examined to determine the optimal electrofusion parameters for nuclear transplantation in mouse embryos. The successful enucleation of donor embryos was 84.9 and 83.3% in two- and eight-cell stage, respectively, and the successful injection of nucleus from two- and eight-cell donor embryos into the perivitelline space of enucleated two-cell embryos were 85.1 and 84.7%, respectively. No significant differences were found in enucleation or injection rate between the cell stages of donor embryos. When the blastomeres of intact two-cell mouse embryos were electrofused in 0.3 M mannitol medium(100 sec., 3 pulses), the fusion rate was similarly 93.2, 92.2 and 92.0% in 1.0, 1.5 and 2.0 kV /crn, respectively, but in vitro development to blastocyst of the fused two-cell embryos was significantly(P<0.05) lower in 2.0 kV/cm (63.4%) than in 1.0 kV/cm (91.7%) or 1.5 kV/cm (82.4%). The development in vitro to eight-cell stage of the reconstituted embryos with nucleus from two-cell stage(45.5%) was significantly(P<0.05) higher than that from eight-cell stage blastomeres (16.7%). The number of blastomeres of the intact embryos at blastocyst stage was 50i0.6 and 552.4 in in vitro and in vivo cultured mouse embryos, respectively, but significantly(P<0.05) decreased to 350.7 in nuclear transplanted blastocyst embryos. The conception rate of mice following embryo transfer was 32.1% in the reconstituted two-cell embryos using two-cell donor nuclei, which was comparable to the fresh two-cell embryos(40.6%). However, the rate of development in vivo to term following embryo transfer of the reconstituted two-cell embryos using two-cell donor nuclei (23.5%) was significantly(P<0.05) lower compared with the percentage of two-cell fresh embryos(31.5%).

The present study was undertaken to determine the optimal condition for parthenogenetic activation of rabbit oocytes by electric stimulation in vitro in an attempt to develop nuclear transplantation techniques for cloning mammalian embryos and animals. Freshly ovulated oocytes were collected from superovulated rabbits from 13 to 26 hrs. after hCG injection. The cumulus-free oocytes were activated parthenogetically by repeated stimuli of square direct electric pulses in O.3M mannitol solution. After applying electric stimulations of different voltages, pulse durations and pulse times, all of the oocytes were cultured in TCM-199 with 10% FCS for 96 hours in a 5% incubator, and their developmental potential in vitro was examined. The higher activation rate (68.9%) was achieved at the voltage of 2.0kv/cm, the pulse duration of 60 sec and three pulse times and the activation rate of 100% was achieved at the pulse duration of 100 and 200 sec, the voltage of 1.5kv/cm and three pulse times. Although the higher rates of activation of oocytes were achieved at 100 and 200 sec, none of them developed to blastocyst in vitro. The oocytes collected 18~20 hours post hCG injection showed the highest rate of activation and development to blastocyst in vitro than the oocytes collected 13~15 or 25~26 hours post hCG injection. Therefore, it can be suggested that the application of electric stimulation of 2.0kv/cm, 60 sec and three pulse times to the oocytes collected at 18~20 hours post hCG injection would be more beneficial for the parthenogenetic activation of oocytes in rabbits.

생물전기화학시스템은 미생물 연료전지로 불리며, 연료전지의 음극, 양극, 분리막으로 구성된 시스템에서 미생물의 활동을 기반으로 유기물을 분해 및 전력생산을 동시에 할 수 있는 장치이다. 생물전기화학시스템을 이용한 전력생산 및 오염물질의 분해의 측면에서 액상 기질을 이용한 많은 연구가 이루어졌다. 액상의 기질은 미생물이 이용하기 쉬운 유기물질을 포함하여 쉽게 전력을 생산할 수 있으나 슬러지의 경우 전처리를 통하여 기질을 미생물이 쉽게 이용할 수 있는 장점이 있다. 그럼에도 불구하고 슬러지를 직접적으로 이용하는 생물전기 화학시스템의 연구는 여전히 초기단계에 있다. 본 연구에서는 하수슬러지를 이용하여 생물전기화학시스템에서 직접적으로 전력을 생산하고 동시에 슬러지 감량화를 이루고자 하였다. 슬러지를 직접적으로 기질로 사용한 경우, 기존의 액상기질을 사용한 반응조와 비교하여 장시간 일정한 전력생산을 기대할 수 있었으며 기질의 충진시간 간격을 길게 하는 장점을 보였다. 그러나, 완전한 기질의 제거는 기대할 수 없었으며 생물전기화학시스템으로 1차적으로 에너지 및 슬러지 감량화를 하여 2차적인 처리가 필요할 것으로 판단되었다.

This paper was conducted experimental work to energy recovery and syngas production using a pilot scale fixed bed gasification process of solid waste. The temperature of gasifier bottom section was the highest at about 522 ~ 808oC. The syngas composition was contained CO 10.0 ~ 11.4%, H2 8.4 ~ 11.3%, CH4 3.7 ~ 3.9%, CnHm 3.3 ~ 4.3% with lower heating value 1,500 kcal/Nm3. About 68.8% of the waste and the air energy is converted to syngas. Approximately 8.4% is lost in heat of heat exchanger and cleaning process and about 0.8% of the heat energy is recycled into the gasifier in the form of preheated air. The electric power output rate was found to range 10.5 to 12.5 kW.

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. 0.57 W/㎡ Al/Graphite. Meanwhile, graphite-only electrodes produced max. 0.11 W/㎡ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was 0.64 W/㎡. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5∼36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.