• Title/Summary/Keyword: Discharge Rate

검색결과 2,267건 처리시간 0.126초

Ni-MH 2차 전기 전극용 Zr-Ti-V-Ni-Mn계 수소저장합금의 조성에 따른 전기화학적 특성 (The electrochemical properties of Zr-Ti-V-Ni-Mn hydrogen storage alloys with various compositions for an electrode of Ni-MH secondary battery)

  • 최승준;정소이;박충년
    • 한국수소및신에너지학회논문집
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    • 제10권4호
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    • pp.219-224
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    • 1999
  • Effects of alloy modification for the $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy as an electrode materials have been investigated. When Ti in the alloy was partially substituted by Zr, the hydrogen storage capacity and subsequently the discharge capacity increased significantly, however, the activation characteristic and rate capability decreased. By substituting Mn with other elements (Cr, Co and Fe) in the alloy, discharge capacity decreased but the cycle life and rate capability were improved. Considering both the discharge capacity, the high rate discharge property and cycle life, the $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$ alloy among the alloys subjected to the test was found to be a prominent alloy for a practical usage.

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(Mm)Ni5계 수소저장합금의 전극 특성 (Electrode Characteristics of the (Mm)Ni5-Based Hydrogen Storage Alloys)

  • 한동수;최승준;장민호;최전;박충년
    • 한국수소및신에너지학회논문집
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    • 제6권1호
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    • pp.35-41
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    • 1995
  • The MmNi-based alloy electrode was studied for use as a negative electrode in Ni-MH battery. Alloys with $MmNi_5-_xM_x$(M=Co,Al,Mn) composition were synthesized, and their electrode charateristics of activation rate, temperature dependence, electrode capacity and cycle life were investigated. With increasing Al content and decreasing Mn content in the alloys, the discharge capacity increased while the cycle life decreased. As x in $MmNi_5-_xM_x$ increased from 1.5 to 2.0, decreasing the Ni content, the discharge capacity, the low temperature property and the rate capability decreased. However its cycle life was improved. Increasing Co content resulted in a prolonged cycle life and decrease of high rate discharge capacity. It can be concluded that the most promising alloy in view of discharge capacity and cycle life is $MmNi_{3.5}Co_{0.7}Al_{0.5}Mn_{0.3}$.

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CNC 첨가에 따른 납축전지의 전기화학적 특성연구 (A Study on the Effects of CNC Addition on Electrochemical Properties of Lead-acid Battery)

  • 김지훈;문준호;문성용;구본근;김기원
    • 한국전기전자재료학회논문지
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    • 제21권3호
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    • pp.279-285
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    • 2008
  • CNC (Carbon Nano Colloid) was used as an additive to the positive electrode to improve the discharge performance of sealed lead-acid batteries, The cathode active material ($PbO_2$) has a relatively low utility of less than 60 % compared with other kind of batteries, such as Ni-MH and Lithium ion, In this study, to overcome the above-mentioned problem we investigated the effects of CNC addition on the enhancement of electrical connection with not-utilized $PbO_2$ and resultantly electrical conductivity of electrode, We examined low rate discharge capacities, high rate discharge capacities and internal resistances of the batteries containing various amounts of CNC. From these results, we found out that the addition of CNC into the positive electrode made a significant improvement in high rate discharge capacity, We also suggested the optimum content of CNC material in positive electrode.

한강수계 유량곡선식 개발 및 수질오염물질 항목간 상관성 분석에 관한 연구- 벽계천 중심으로 - (Study on the Analysis of Development of Stage-Discharge Curve for Han River and Correlation between Items of Water Pollutants- Focused on Byeokgyeo Stream -)

  • 홍성호;반종석;전항배
    • 한국물환경학회지
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    • 제28권3호
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    • pp.394-400
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    • 2012
  • We drew the stage-discharge relations of Byeokgye Stream, located in Yangpyeong-gun, Gyeonggi-do, and analysed the correlation between items of water pollutants by measuring the flow rate and water pollutants thirty-four times from April 2010 to December 2010. The results showed that it tended to be low water season from April to June and from October and December, while tending to be water season from July to September. The average flow rate was $2.137\;m^3/sec:\;0.464\;m^3/sec$ in low water season and $13.970\;m^3/sec$ in high water season. The stage-discharge curve thereon was $Q=40.107{\times}(h-1.200)^{2.877}$. As to the correlations, the correlation between the water temperature and COD was 0.58, and the correlations of SS with BOD and COD were 0.46 and 0.40 respectively. The correlation between SS and T-P was 0.73, showing higher than other items.

Efficacy of mid-upper arm circumference in identification, follow-up and discharge of malnourished children during nutrition rehabilitation

  • Mogendi, Joseph Birundu;De Steur, Hans;Gellynck, Xavier;Saeed, Hibbah Araba;Makokha, Anselimo
    • Nutrition Research and Practice
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    • 제9권3호
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    • pp.268-277
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    • 2015
  • BACKGROUND/OBJECTIVES: Although it is crucial to identify those children likely to be treated in an appropriate nutrition rehabilitation programme and discharge them at the appropriate time, there is no golden standard for such identification. The current study examined the appropriateness of using Mid-Upper Arm Circumference for the identification, follow-up and discharge of malnourished children. We also assessed its discrepancy with the Weight-for-Height based diagnosis, the rate of recovery, and the discharge criteria of the children during nutrition rehabilitation. SUBJECTS/METHODS: The study present findings from 156 children (aged 6-59 months) attending a supplementary feeding programme at Makadara and Jericho Health Centres, Eastern District of Nairobi, Kenya. Records of age, weight, height and mid-upper arm circumference were selected at three stages of nutrition rehabilitation: admission, follow-up and discharge. The values obtained were then used to calculate z-scores as defined by WHO Anthro while estimating different diagnostic indices. RESULTS: Mid-upper arm circumference single cut-off (< 12.5 cm) was found to exhibit high values of sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio at both admission and discharge. Besides, children recorded higher rate of recovery at 86 days, an average increment of 0.98 cm at the rate of 0.14mm/day, and a weight gain of 13.49gm/day, albeit higher in female than their male counterparts. Nevertheless, children admitted on basis of low MUAC had a significantly higher MUAC gain than WH at 0.19mm/day and 0.13mm/day respectively. CONCLUSIONS: Mid-upper arm circumference can be an appropriate tool for identifying malnourished children for admission to nutrition rehabilitation programs. Our results confirm the appropriateness of this tool for monitoring recovery trends and discharging the children thereafter. In principle the tool has potential to minimize nutrition rehabilitation costs, particularly in community therapeutic centres in developing countries.

Kinetic Study on the Low-lying Excited States of Ga Atoms in Ar

  • Kuntack Lee;Ju Seon Goo;Ja Kang Ku
    • Bulletin of the Korean Chemical Society
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    • 제15권8호
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    • pp.663-669
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    • 1994
  • Decay kinetics of Ga(5s), Ga(5p) and Ga(4d) atoms in Ar were studied by laser induced fluorescence technique. Theground state gallium atoms in the gas phase were generated by pulsed dc discharge of trimethyl gallium and argon mixtures. Both pulsed discharge and YAG-DYE laser system were controlled by a dual channel pulse generator and the delay time between the end of discharge and laser pulses was set 3.0-6.0 ms. The Ga(5s) and Ga(4d) atoms were generated by single photon excitation from the ground state Ga atoms and radiative lifetimes as well as the total quenching rate constants in Ar were obtained from the pressure dependence of the fluorescence decay rates. The Ga(5p) atoms were populated by a two-photon excitation method and the cascade fluorescence from Ga(5s) atoms were analyzed to extract quenching rate constant of Ga(5p) atoms by Ar in addition to radiative lifetimes of Ga(5p) state. The magnitudes of the quenching rate constants by Ar for the low-lying excited states of Ga atoms are 1.6-3$ {\times}10^{-11}cm^3$ molecul$e^{-1}s^{-1}$, which are much larger than those for alkali, alkaline earth and Group 12 metals. Based on the measured rate constants, kinetic simulations were done to assign state-to-state rate constants.

방전 플라즈마에 의한 이산화탄소 전환 효율 상승에 관한 연구 (Study of the Increase of Conversion Efficiency of $CO_2$ by Discharge Plasmas)

  • 조문수;곽동주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.904-907
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    • 2002
  • In this study, the plasma-assisted $CO_2$ conversion characteristics were investigated in the streamer corona discharge and silent discharge reactors with dielectric of $Al_2O_3$, to improve the conversion efficiency $CO_2$. Some discharge characteristics of $CO_2$ as parameters of gap spacing and applied voltage frequency, in both corona and silent discharge reactor were also obtained. The maximum $CO_2$ conversion rate was 10.1 [%] under the 5.2 [W] of discharge power and 250 [Hz] of applied voltage frequency.

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글로우 방전 플라즈마에 의한 탄산가스 전환특성 (Conversion Characteristics of $CO_2$ by Glow Discharge Plasm)

  • 곽동주;하양진;신용섭;최연석
    • 한국전기전자재료학회논문지
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    • 제11권3호
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    • pp.248-254
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    • 1998
  • In the present study the glow discharge characteristics of $CO_2$ in a parallel plate electrode system were investigated, and the decomposition properties of $CO_2$ concerned with the discharge characteristics were discussed. The results show that $CO_2$ concentration decreases with increase in discharge power and decrease in gas pressure. The maximum conversion of $CO_2$ by glow discharge was 52% under the conditions of gas pressure, 10m Torr and 290W of discharge power.

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Off-line PD Model Classification of Traction Motor Stator Coil Using BP

  • Park Seong-Hee;Jang Dong-Uk;Kang Seong-Hwa;Lim Kee-Joe
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권6호
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    • pp.223-227
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    • 2005
  • Insulation failure of traction motor stator coil depends on the continuous stress imposed on it and knowing its insulation condition is an issue of significance for proper safety operation. In this paper, application of the NN (Neural Network) as a scheme of the off-line PD (partial discharge) diagnosis method that occurs at the stator coil of a traction motor was studied. For PD data acquisition, three defective models were made; internal void discharge model, slot discharge model and surface discharge model. PD data for recognition were acquired from a PD detector. Statistical distributions and parameters were calculated to perform recognition between model discharge sources. These statistical distribution parameters are applied to classify PD sources by the NN with a good recognition rate on the discharge sources.

$Al_2O_3$ 세라믹 유전체 오존발생기의 방전면적 특성 (Discharge Area Characteristics of Ozonizer with $Al_2O_3$ Dielectric)

  • 박현미;송현직;이상근;임창호;윤병한;김종현;이광식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.2214-2216
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    • 2005
  • This paper is researched discharge and ozone generation characteristics of ozonizer using $Al_2O_3$ Ceramic dielectric. The discharge characteristics with variation of the discharge electrode area is studied. The characteristics of ozone concentration. ozone generation and ozone yield were measured to discharge power, discharge electrode area and supplied gas flux for oxygen and air. The solubility of ozone for water concentrations and ozone generations proportional to discharge power and discharge electrode area. Ozone yield has slowly increase with Increasing discharge power at high flow-rate. As the result, the maximum values of ozone characteristics ozone generation and ozone yield, can be obtained 5817[ppm] and 36[g/kWh]. We make enough the ozone concentration as the air in the home. An electric discharge electrode area is apt to shrink gradually into a miniaturization trend of the ozonizer but the enlargement of the occurrence flight of the electric discharge area gives the characteristic enhance the aid in the identity condition through the structure improvement.

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