• Title/Summary/Keyword: Specific charge

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Spray Characteristics of Charge Injected 2-fluid Nozzle for Non-conducting Liquid (비전도성 액체의 전하주입형 2-유체 노즐에 대한 분무 특성)

  • Park, Min-Gyu;Choi, Young-Joo;Kim, Sang-Soo
    • Journal of ILASS-Korea
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    • v.11 no.3
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    • pp.155-160
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    • 2006
  • Spray characteristics of charge injected 2-fluid nozzle for non-conducting liquid have been studied. Spray current, specific charge and SMD of diesel have been measured. Spray current and specific charge are proportional to applied voltage. Air flow did not effect on spray current and specific charge. SMD decreases as air flow rate increases and decreases as applied voltage increases additionally. Spray angle increases as applied voltage increases. Fine droplets are obtained by charge injected 2-fluid nozzle without charge loss.

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A study of the hazard of fire and explosion due to electric charge by Gas-Solids flow in pipeline

  • Chung Jae Hee;Seo Dae Won;Koo Ja Hyeuk;Kim Sung Jun;An Heau Seak;Kim Joon Ho;Hong Sung Kyung;YAMAGUMA Mizuki;KODAMA Tsutomu
    • Journal of the Korean Institute of Gas
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    • v.4 no.3 s.11
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    • pp.33-38
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    • 2000
  • When fire and explosion accidents have occurred due to a leak of the flammable gas involving the LNG & LPG in an industrialized society, it is a very important problem. Accordingly, in this paper, we have compared and analyzed the occurrence transition and the electrostatic energy according to dust supplies and pressure variations for the electric charge due to the gas-solids of pipe flow. As the experimental results, if dust amounts and the initial pressure increased, electric charge in the pipe and the exit increased. The Specific charge of $Fe_2O_3$ increased proportionally if the initial pressure increased but if the quantity of dust increased, the specific charge decreased. Energy increased significantly as the dust amounts and the initial pressure increased. The possibility of fire and explosion exist in the measuring point(M 1) and the Faraday cage if natural gas and LPG were used.

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Electrode of Low Impedance by Polypyrrole Addition for Supercapacitor (폴리피롤 첨가에 의한 supercapacitor용 저 임피던스 전극)

  • 김경민;장인영;강안수
    • Proceedings of the Safety Management and Science Conference
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    • 2003.11a
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    • pp.343-350
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    • 2003
  • The best Ppy weight ratio was 7 wt% and the optimal electrode composition ratio was 78 : 17 : 5 wt.% of (MSP-20 : BP-20 =1 : 1), (Super P : Ppy =10 : 7) and P(VdF-co-HFP). Implantation of Ppy as the conducting agents have led to superior electrochemical characteristics because of the low of internal resistance and faradaic capacitance. The result of unit cell with Ppy 7 wt% were as follows: 28.02 Fig of specific capacitance, 1.34 Ω of DC-ESR and 0.36 Ω of AC-ESR. Unit cell showed a good stability up to 200 charge-discharge cycles, retaining 82% of their original capacity at 200 cycles. From the analysis of impedance, the electrodes with Ppy 7 wt% showed low ESR, low charge transfer resistance and quick reaction rate. It was inferred that quick charge-discharge was possible. As compared with the specific capacitance (rectangular shape) of CV, it was also concluded that the specific capacitance originated from thecompound phenomena of the faradaic capacitance by oxidation and reduction of Ppy and the non-faradaic capacitance by adsorption-desorption of activated carbon.

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Development of Silicon Coated by Carbon with PVDF Precursor and Its Anode Characteristics for Lithium Batteries (PVDF 전구체를 이용한 탄소 도포 실리콘 재료의 개발 및 리튬이차전지 음극특성)

  • Doh, Chil-Hoon;Jeong, Ki-Young;Jin, Bong-Soo;Kim, Hyun-Soo;Moon, Seong-In;Yun, Mun-Soo;Choi, Im-Goo;Park, Cheol-Wan;Lee, Kyeong-Jik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.7
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    • pp.636-643
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    • 2006
  • Si-C materials were synthesized by the heating the mixture of silicon and polyvinylidene fluoride (PVDF). The electrochemical properties of the Si-C materials as the high capacitive anode materials of lithium secondary batteries were evaluated by the galvanostatic charge-discharge test through 2032 type $Si-C{\mid}Li$ coin cells. Charge-discharge tests were performed at C/10 hour rate(C = 372 mAh/g). Initial discharge and charge capacities of $Si-C{\mid}Li$ cell using a Si-C material derived from PVDF(20wt.%) were found to be 1,830 and 526 mAh/g respectively. The initial discharge-charge characteristics of the developed Si-C electrode were analyzed by the electrochemical galvanostatic test adopting the capacity limited charge cut-off condition(GISOC). The range of reversible specific capacity IIE(intercalation efficiency at initial discharge-charge) and IICs(surface irreversible specific capacity) were 216 mAh/g, 68 % and 31 mAh/g, respectively.

A Study on the Determination of Suitable Specific Charge in Tunnel Blasting Design (터널발파설계에서 적정장약량산정에 관한 연구)

  • Jeong, Dong-Ho;Kim, Seon-Hong;Bae, Hyo-Jin;Seok, Jin-Ho;Choo, Yong-Beom
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.3 no.1
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    • pp.21-26
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    • 2001
  • Till now a lot of studies has been performed to increase the efficiency of tunnel blasting. Nevertheless there are still uncertainties of input parameter to determine the specific charge. In order to solve this problem, the rock types and the charges of 17 road tunnel sites were analyzed. As a result of these analyses an empirical formula depending on rock type and charge was developed. Through this formula rational tunnel blasting will be designed by quantitative method rather than by assumption.

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Development of Silicone coated by Carbon driven PVDF and its anode characteristics for Lithium Battery (전구체로서 PVDF를 이용한 탄소 도포 실리콘 재료의 개발 및 리튬이차전지 음극 특성)

  • Doh, Chil-Hoon;Jeong, Ki-Young;Jin, Bong-Soo;Kim, Hyun-Soo;Moon, Seong-In;Yun, Mun-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.350-351
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    • 2005
  • The electrochemical behavior of Si-C material synthesized by heating the mixture of silicon and polyvinylidene fluoride (PVDF). Coin cells of the type 2025 were made using the synthesized material and the electrochemical studies were performed. Si-C/Li cells were made by using the developed Si-C material. Charge/discharge test was performed at 0.1C hour rate. Initial charge and discharge capacities at Si-C material derived from 20 wt.% of PVDF was found to be 1,830 and 526 mAh/g respectively. Initial charge/discharge characteristics of the electrode were analyzed. The level of reversible specific capacity was about 216 mAh/g at Si-C material derived from 20 wt.% of PVDF, IIE, intercalation efficiency at initial charge/discharge, was 68 %. Surface irreversible specific capacity was 31 mAh/g, and average specific resistance was 2.6 ohm*g.

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Capacity Design of Lithium Ion Battery Based on the Characteristics of Materials (${\cdot}$부극 재료의 특성에 따른 리튬이온전지의 용량설계)

  • Moon Seong-In;Doh Chil-Hoon;Yun Seong-Kyu;Yum Duk-Hyung
    • 한국전기화학회:학술대회논문집
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    • 1998.12a
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    • pp.7-27
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    • 1998
  • In order to design capacity of lithium ion battery, some calculations were carried out based on the characteristics of materials by the given battery shape and dimension. The principle of design was built by the interpretation of the correlation of material, electrochemical and battery factors. Parameters of materials are fundamental physical properties of constituent such as cathode. separator, anode, current collectors and electrolyte. Electrochemical factor includes potential pattern as a function of specific capacity, specific discharge capacity(or initial irreversible specific capacity or Ah efficiency) as a function of specific charge capacity and material balancing. Parameters of battery are dimension, construction hardware and performance. Battery capacity was simulated for a lithium cobalt dioxide as cathode and a hard carbon as anode to achieve 1100 mAh for the charge limit voltage of 4.2V, the weight ratio(+/-) of 2.4 and ICR18650. A fabricated test cell (ICR18650) which have weight ratio(+/-) of 2.4 discharged to 1093 mAh for the charge limit voltage of 4.2V. The sequential discharge capacity show good correspondence with designed capacity.

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Modularized Charge Equalization Converter for Hybrid Electric Vehicle Lithium-Ion Battery Stack

  • Park, Hong-Sun;Kim, Chong-Eun;Kim, Chol-Ho;Moon, Gun-Woo;Lee, Joong-Hui
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.350-352
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    • 2007
  • Modularized charge equalization converter for HEV lithium-ion battery cells is proposed in this paper, in which intra-module and inter-module charge equalization can be achieved at the same time. For intra-module charge equalization, the conventional flyback DC/DC converters of low power and small size are employed, in which all of the primary sides are coupled in parallel for selective charge of the specific under charged cell within the module. For inter-module charge equalization, the flyback DC/DC converters are also added, in which all the secondary windings are electrically linked in parallel for automatic charge balancing among the modules. An engineering sample of forty cells hiring the proposed cell balancing scheme is implemented and its experimental result shows that the proposed modularized charge equalization circuit has good cell balancing performance.

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Inflence of carbonization temperature on electrochemical performance of multi-walled carbon nanotube/poly(vinylidene fluoride) composite-derived carbons (탄소나노튜브/폴리비닐리덴 플루오라이드 복합체로부터 제조된 탄소의 탄화온도에 따른 전기화학적 특성)

  • Kim, Ji-Il;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.214.2-214.2
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    • 2011
  • In this work, porous carbon based electrodes are prepared by carbonization using poly(vinylidene fluoride) (PVDF)/carbon nanotube (CNT) composites to further increase the specific capacitance for supercapacitors. Electrode materials investigate the aspects of specific capacitance, pore size distribution and surface area: influence of carbonization temperatures of PVDF/CNT composites. The electrochemical properties are investigated by cyclic voltammetry, impedance spectra, and galvanostatic charge-discharge performance with in $TEABF_4$ (tetraethylammonium tetrafluoroborate)/acetonitrile as non-aqueous electrolyte. From the results, the highest value of specific capacitance of ~101 $F{\cdot}g^{-1}$ is obtained for the samples carbonized at $600^{\circ}C$. Furthermore, pore size of samples control be low 7 nm through carbonization process. It is suggested that micropores significantly contribute to the specific capacitance, resulting from improved charge transfer.

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Electrochemical Advanced Oxidation of Lamotrigine at Ti/DSA (Ta2O5-Ir2O5) and Stainless Steel Anodes

  • Meena, Vinod Kumar;Ghatak, Himadri Roy
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.292-307
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    • 2022
  • The study presents kinetics of degradation and mineralization of an anti-epileptic drug Lamotrigine (LAM) in the aqueous matrix by electrochemical advanced oxidation process (EAOP) on Ti/DSA (Ta2O5-Ir2O5) and Stainless Steel (SS) anodes using sodium sulphate as supporting electrolyte. On both the anodes, kinetic behaviour was pseudo-first-order for degradation as well as mineralization of LAM. On Ti/DSA anode, maximum LAM degradation of 75.42% was observed at an associated specific charge of 3.1 (Ah/litre) at a current density of 1.38 mA/cm2 and 100 ppm Na2SO4 concentration. Maximum mineralization attained was 44.83% at an associated specific charge of 3.1 (Ah/litre) at a current density of 1.38 mA/cm2 and 50 ppm concentration of Na2SO4 with energy consumption of 2942.71 kWh/kgTOC. Under identical conditions on SS anode, a maximum of 98.92% LAM degradation was marked after a specific charge (Q) of 3.1 (Ah/litre) at a current density of 1.38 mA/cm2 and 100 ppm concentration of Na2SO4. Maximum LAM mineralization on SS anode was 98.53%, marked at a specific charge of 3.1 (Ah/litre) at a current density of 1.38 mA/cm2 and 75 ppm concentration of Na2SO4, with energy consumption of 1312.17 kWh/kgTOC. Higher Mineralization Current Efficiency (MCE) values were attained for EAOP on SS anode for both degradation and mineralization due to occurrence of combined electro-oxidation and electro-coagulation process in comparison to EAOP on Ti/DSA anode due to occurrence of lone electro-oxidation process.