• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.245-250
• /
• 2016

Manganese dioxide is the material which has a good characteristic property for a secondary cell. We have surveyed on rechargeable battery of zink-manganese dioxide using aqueous solution and we also surveyed on redox reversibility of zink-manganese dioxide for checking up possibility for a secondary cell. We have found out to be active for charging and discharging of those.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.41 no.2
• /
• pp.165-170
• /
• 2005

Al-Zn alloy/$MnO_2$, seawater cell was considered as a primary aqueous cell with an average voltage range from 1.0 to 1.1V, and the electrolyte of seawater was uptaken into the cell. Eventually, the capacity of its usage will be used for long-term. However, the more use of this cell, the higher corrosion phenomenon of the electrode occurred. Due to its corrosion phenomenon, one main default has been observed with gradual decrease during a discharge process. In this research, a common-used active material for anode was $LiNiO_2$. An active material for cathode, $Zn_{X}FeS_2$ was synthesized in high temperature by uptaken a small amount of 1.3 wt% of ZnS into $FeS_2$, one of the transition-metal dichalcogenides in high temperature. Consequently, based on their usages shown above, this secondary aqueous lithium cell could be more developed. This cell was shown as remarkable charge/discharge performance during the charge/discharge processes. This cathode with active material was given a considerable efficiency of inserting $Li^+$ ions. Moreever, in accordance with the characteristic of the crystal structure for $Zn_{x}FeS_2$, a small amount of ZnS was added which made it possible to reduce prominently velocity of corrosion during the charge/discharge cycle. By applying those merits, Al-Zn alloy/$MnO_2$ seawater cell will be used as a fundamental data in order to transform into a secondary aqueous cell.

• 전기의세계
• /
• v.39 no.10
• /
• pp.7-10
• /
• 1990

태양광에 의해 전기가 발생되는 광기전력 효과는 이미 19세기 중반에 발견 되었으며 이를 실제로 이용하기 시작한 것은 1950년대에 등대, 통신중계소 및 인공위성 전원용으로 사용하기 시작하면서 부터 인것은 잘 알려진 사실이다. 그후 선진 각국들은 꾸준한 연구개발 노력을 하여왔으나 태양전지를 민수용으로 사용키 위해 본격 개발을 시작한 것은 아무래도 70년대의 1,2차 석유파동을 겪은 후부터라고 생각된다. 기존의 화석에너지원에 비하여 많은 장점을 가지고 있으면서도 빠른 속도로 실용화가 되지 않았던 이유는 경제성이 현저히 뒤져있었기 때문이며, 기술적으로도 화석에너지나 원자력에 의한 대규모 전력생산을 대체 할 수 있는 수준과는 거리가 있기 때문이다. 그러나 관련기술 개발, 범 세계적인 환경에의 관심고조, 확석에너지원의 유한성에 대한 인식심화 등에 힘입어 탱양광발전은 그 나름대로의 수요 영역을 확보해 가는 추세이며 이는 관련기술 개발과 같은 내적인 변화와 화석에너지 가격의 변화, 환경규제의 강도 등 외적 환경 변화 속도에 따라 보다 가속화 될 전망이므로 우리나라의 태양광발전 기술개발 현황과 정부의 기술개발 전략, 제도 및 향후 수요 환경등을 개관해 보기로 한다.

• Applied Chemistry for Engineering
• /
• v.10 no.6
• /
• pp.814-821
• /
• 1999

The specific capacitance characteristics of the electric double layer capacitors(ELDC) which were made of phenol based activated carbon fiber(ACF) electrodes. Also the effect of aqueous electrolytes on the cell performance has been investigated with respect to different specific surface areas of electrodes and different kinds of aqueous electrolytes. It has been shown that larger surface area and pore size, higher conductivity of electrodes, and higher ion mobility of electrolytes have better specific capacitances. It has been found that heat treatment at $1200^{\circ}C$ and $CO_2$ post-activation at $900^{\circ}C$ of the electrode are effective to improve the specific capacitance over 145F/g and 165F/g, respectively. The EDLC showed high efficiency and long cycle life over 30000 cycles.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1996.04a
• /
• pp.161-161
• /
• 1996

본 연구에서는 차량(승용차) 시동용 수퍼캐패시터-밧데리 조합시스템에 적용할 시작품 전기이중층 수퍼캐패시터(super-capacitor:SC)를 설계 제작 개발하고 그 성능 특성을 확인하였다. 재래식의 차량용 밧데리의 비동력(specific power)이 100~200 W/kg에 비하여 전기이중층 SC의 경우는 1,000~3,000 W/kg으로 단위 총량당의 동력이 매우 크다. 또한 충방전시의 화학반응이 없는 관계로 인하여 충전식 2차 전지에 비하여 사용수명이 매우 길다. 이러한 SC를 기존의 밧데리와 함께 조합하여 차량 시동용으로 사용하게 되면 밧데리의 사용수명을 2~3배 길게 할 수 있으며 밧데리는 시동에 필요한 큰 전류의 방전이 요구되지 않으므로 그 용량과 크기가 대체로 절반이상 줄어든다. 또한 매우 낮은 온도의 기후조건에서는 밧데리의 방전효율이 급격히 저하되므로 이를 대비하여 필요 이상의 과용량, 과중량 밧데리의 사용이 실제로 행해지고 있으나 조합시스템의 차량 시동시에는 SC가 갖는 특성상 -5$0^{\circ}C$까지의 기후조건에서도 방전효율이 크게 저하되지 않은 채 시동전류를 공급해주므로 혹한지역이나 혹한시의 차량시동에도 탁월한 시동성능을 갖는다. 설계 제작된 SC는 저장에너지 6KJ, 정격전압 12Volt, 설계축전용량 70F 그리고 사용은 도 범위가 섭씨 영하 25도에서 영상 50도이며 무공해성 수용성 전해질을 사용하였으며, 제작된 CS는 사용온도 범위에서 축전용량 65F - 85F, 내부저항 1.8mOhm - 5.2mOhm의 변화를 보였으며, 정상시동에 필요한 방전전류 300Amp의 경우 2.6초의 방전시간, 약 89%의 방전효율을 보였다. 현재까지 상온하에서 30.000회의 충방전 시험결과로서는 방전효율의 저하가 없는 양호한 성능을 보였으며, SC의 시범 작동시험을 실차(소나타 1800cc)에 장착하여 수행한 결과 20회 이상의 연속시동에서도 아무런 문제점 없이 잘 동작하였다.

• Journal of Climate Change Research
• /
• v.1 no.1
• /
• pp.1-11
• /
• 2010

This study is analyzed based on the statistical data for the effect of Kyoto Protocol which is adopted on 1997. The first greenhouse gas obligation reduction countries such as OECD (Organization for Economic Cooperation and Development), and the first non-obligated developing countries such as China and India, the increasing rate of carbon dioxide emission displayed -10.2% and 88.1% in 2005 with respect to 1990, respectively. This increasing rate is not only shows statistically significant differences but also shows significant meanings when we consider the global increasing rate of carbon dioxide is 29.1%. Changes in the carbon dioxide emissions are also analyzed based on the time of the adaptation of Kyoto Protocol, time of the publication of the second and third reports of IPCC, and withdrawal of the Kyoto Protocol of the United States. Withdrawal of the Kyoto Protocol of the United States is the most significantly affected to the differences in the carbon dioxide emission rates rather than the adaptation of Kyoto Protocol, international agreement on the greenhouse gas reduction, and belief on the scientific evidence for the reasons for increasing carbon dioxide concentrations. Therefore, acceptance of the post-Kyoto Protocol in the United States is very important in order to success as a climate regime.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.1
• /
• pp.15-21
• /
• 1986

This study was conducted to research the industrial utilizaion of the maize germs separated in the manufacture of the cornstarch. The maize germs contained crude protein (25.3%) and crude fat (19.2%), with the 512 Kcal/100g of determined food energy values. It was found to have the valuable amounts of essential minerals, such as the content of calcium and phosphorus were low (53.0, 12.3mg%), while those of potassium (495.4mg%), magnesium (95.0mg%), zinc (48.3ppm) and manganese (45.2ppm) were plentiful. It was noted that the iodine value was 44.0, saponification value 292.3, acid value 1.5 and peroxide value about 3.3. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid, whereas, the contents of glycolipid and phospholipid were scarcely. The major fatty acids in total lipids were linoleic $(60{\sim}62.5%)$, oleic $(20{\sim}22.5%)$ and palmitic $(10{\sim}13.5%)$ acids. The content of the unsaturated fatty acids was more predominant than that of the saturated fatty acids. The content of the insoluble proteinous nitrogen (32.5%) was the most abundant. whereas, the contents of soluble proteinous nitrogen (12.7%) and peptide proteinous nitrogen (3.3%) were low. The major amino acids of the maized germs were glutamic, glycine, alanine and aspartic. It has been identified by the SDS-disc electrophoresis that the protein of maized germs had $5{\sim}6$ bands. Compared with standard substances, the molecular weight of the main protein was estimated to be $14,500{\sim}24,500$.