• Title/Summary/Keyword: Po Kim

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Design on a Dual Impulse Surge Protector for the Power over Ethernet Devices (PoE(Power Over Ethernet)에서 임펄스성 서지보호 이중화 장치 설계)

  • Jin, Jong-Ho;Kim, Young-Jin;Rhee, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.8
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    • pp.927-934
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    • 2015
  • In this paper, in order to prevent impulse surge PoE(Power Over Ethernet) communications error caused by natural phenomenon in industrial sites, countermeasure design of impulse surge of PoE communications equipment is suggested by designing dual impulse surge protection circuit. In order to analyze characteristic of impulse surge noise signal, surge generating device which meet international standard IEC 61000-4-5 is invented. And this device shows that surge signal is weakened by designing dual PoE power supply protection circuit by connecting surge generating device to the PoE data transfer line.

A Design of Test Equipment for Battery Automatic Charging-Discharging Control Using LabVIEW (LabVIEW를 이용한 배터리 자동 충·방전 제어 테스트 장치 설계)

  • Park, Byeong-Ju;Moon, Chae-Joo;Jeong, Moon-Seon;Park, Ji-Ye;Kim, Yi-Yoon;Kim, Yeong-Jung
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.559-560
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    • 2011
  • 최근 전기자동차와 신재생에너지 발전 시스템의 전기 저장장치로 고용량 2차 전지의 개발 및 상용화가 활발히 이루어지고 있으며, 기술 연구 또한 꾸준히 진행되고 있다. 배터리에 대한 활용도가 높아지면서 배터리의 성능평가에 대한 관심도 높아지고 있다. 본 논문에서는 LabVIEW를 이용하여 배터리 자동 충 방전 제어 테스트 장치를 구축하여, 원격제어 및 실시간 모니터링을 통해 데이터 분석 및 저장이 가능하며, 다양한 배터리의 성능평가를 설정 값 변경으로 손쉽게 평가 할 수 있도록 장치를 개발 하였다.

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A Feasibility Study of Using Diesel/Biodiesel-Pyrolysis Oil-Butanol Blends in a Diesel Engine (디젤유/바이오디젤유-열분해유-부탄올 혼합유의 디젤 엔진 적용 가능성에 관한 연구)

  • Kim, Hoseung;Jang, Youngun;Lee, Seokhwan;Kim, Taeyoung;Kang, Kernyong;Yoon, Junkyu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.5
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    • pp.116-125
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    • 2014
  • Pyrolysis oil (PO), derived from biomass through fast pyrolysis process have the potential to displace significant amounts of petroleum fuels. The PO derived from wood has been regarded as an alternative fuel to be used in diesel engines. However, the use of PO in a diesel engine is very limited due to its poor properties like low energy density, low cetane number, high acidity and high viscosity of PO. Therefore, one of the easiest way to adopt PO to diesel engine without modifications is blended with other fuels that have high centane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel or biodiesel. Thus, to stabilize a homogeneous phase of diesel/biodiesel-PO blends, a proper surfactant should be used. Nevertheless, PO which was produced from different biomass type have varied characteristics and this complicates the selection of a suitable additive for a specific PO-diesel emulsion. In this regard, a more simple approach such as the use of a co-solvent like ethanol or butanol to induce a more stable phase of the PO-diesel mixture could be a promising alternative. In this study, a diesel engine operated with diesel/biodiesel-PO-butanol blends was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine were examined under the engine loads of IMEP 0.2 ~ 0.8MPa.

Synthesis of Hydroxycalciumphosphate (수산화 인산칼슘의 합성)

  • Hwang, Young-Gil;Kim, Youn-Soo;Kim, Jae-Il
    • Resources Recycling
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    • v.5 no.3
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    • pp.50-55
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    • 1996
  • The synthesis of Ca,,(PO,),(OH), by adding (NFIa)J),HPO, to lhe solution of Ca(NO,), dlssolvad CaO in HNO, and contmlled pH with NH,OH was carried out for certain time at room temperahire and atmosphere. Ca,,(PO,),(OH), was rorrned at the range from pN 10 to pH 13. The particle s~zeof Ca,,(PO,),(OH)i was 0.1-0.5 &In. Thc optimum reaction lime was 30 min, and the temperature was 40-70$^{\circ}$C. the shape also was not changed in spite of heating to iDVC hr 1 hour the c~ystalliratian temperature was 90$^{\circ}$C Ca,,(PO,),(OH), was calcinatcd and the shape also was not changzd, in spile of hcaling to 500$^{\circ}$C for 1 hour. But Ca,,(PO,),(OH), calcinated for lhour al 800$^{\circ}$C was changed to the spheric particle of Ca,,,(PO,),(OH),, CaO and Ca,(PO,),.

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Application of Montmorillonite as Capping Material for Blocking of Phosphate Release from Contaminated Marine Sediment (해양오염퇴적물 내 인산염 용출차단을 위한 피복소재로서의 몬모릴로나이트 적용)

  • Kang, Ku;Kim, Young-Kee;Hong, Seong-Gu;Kim, Han-Joong;Park, Seong-Jik
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.8
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    • pp.554-560
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    • 2014
  • To investigate the applicability of montmorillonite to capping material for the remediation of contaminated marine sediment, adsorption characteristics of $PO{_4}{^{3-}}$ onto montmorillonite were studied in a batch system with respect to changes in contact time, initial concentration, pH, adsorbent dose amount, competing anions, adsorbent mixture, and seawater. Sorption equilibrium reached in 1 h at 50 mg/L but 3 h was required to reach sorption equilibrium at 300 mg/L. Freundlich model was more suitable to describe equilibrium sorption data than Langmuir model. The $PO{_4}{^{3-}}$ adsorption decreased as pH increased, due to the $PO{_4}{^{3-}}$ competition for favorable adsorption site with OH- at higher pH. The presence of anions such as nitrate, sulfate, and bicarbonate had no significant effect on the $PO{_4}{^{3-}}$ adsorption onto the montmorillonite. The use of the montmorillonite alone was more effective for the removal of the $PO{_4}{^{3-}}$ than mixing the montmorillonite with red mud and steel slag. The $PO{_4}{^{3-}}$ adsorption capacity of the montmorillonite was higher in seawater than deionized water, resulting from the presence of calcium ion in seawater. The water tank elution experiments showed that montmorillonite capping blocked well the elution of $PO{_4}{^{3-}}$, which was not measured up to 14 days. It was concluded that the montmirillonite has a potential capping material for the removal of the $PO{_4}{^{3-}}$ from the aqueous solutions.

Cellular Localization and Translocation of Duplication and Alternative Splicing Variants of Olive Flounder Phospholipase C-δ1 (넙치 3가지 타입 인지질가수분해효소(PLC-δ1)의 세포 내 위치 및 이동)

  • Kim, Na Young;Kim, Moo-Sang;Jung, Sung Hee;Kim, Myoung Sug;Cho, Mi Young;Chung, oon Ki;Ahn, Sang Jung
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1369-1375
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    • 2017
  • The purpose of this study was to investigate the cellular characterization of phospholipase C-${\delta}1$ in olive flounders (Paralichthys olivaceus). In general, phospholipase C signaling pathways are distributed in nuclei at plasma membranes and in cytoplasms, although the pathways' nuclear localization mechanisms are unclear. P. olivaceus duplicates type-A PoPLC-${\delta}1$ (PoPLC-${\delta}1A$), which has a high similarity to the human isoform PLC-${\delta}$; type-B PoPLC-${\delta}1$ (PoPLC-${\delta}1B$ [Sf]), which has a low similarity to the human isoform PLC-${\delta}$ and the alternative splice variant PoPLC-${\delta}1B$ (Lf), which has a nuclear localization signal (NLS) and a nuclear export signal (NES) for nuclear imports and exports, respectively. This study confirmed the effects of the cellular localization and translocation of GFP-tagged PoPLC-${\delta}1A$, PoPLC-${\delta}1B$ (Sf) and PoPLC-${\delta}1B$ (Lf). It administered treatments of $Ca^{2+}$ ionophore ionomycin and endoplasmic reticulum (ER)-$Ca^{2+}$ pump inhibitor thapsigargin to hirame natural-embryo (HINAE) cells. A laser-scanning confocal microscope was used. GFP-tagged PoPLC-${\delta}1A$ was distributed to the cellular organelles, rather than to the cytoplasms and cytomembranes, when PoPLC-${\delta}1B$ (Lf) and PoPLC-${\delta}1B$ (Sf) were localized at the plasma membranes. The treatments of ionomycin and thapsigargin showed the accumulation of PoPLC-${\delta}1A$ in the nuclei when PoPLC-${\delta}1B$ (Lf) nucleocytoplasmic shuttling and PoPLC-${\delta}1B$ (Sf) nucleocytoplasmic shuttling were not observed. The results were the first evidence that PoPLC-${\delta}1A$, which contains functional, intact NES sequences, has a main role in nucleocytoplasmic shuttling and translocation in fish.

Electrochemical Properties of LiFePO4 Cathode Materials for Lithium Polymer Batteries (리튬폴리머전지용 정극활물질 LiFePO4의 전기화학적 특성)

  • Kong Ming-Zhe;Kim Hyun-Soo;Gu Hal-Bon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.6
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    • pp.519-523
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    • 2006
  • $LiFePO_4$ has been received attention as a potential cathode material for the lithium secondary batteries. In our study, $LiFePO_4$ cathode active materials were synthesized by a solid-state reaction. It was modified by coating $TiO_2$ and carbon in order to enhance cyclic performance and electronic conductivity. $TiO_2$ and carbon coatings on $LiFePO_4$ materials enhanced the electronic conductivity and its charge/discharge capacity. For lithium polymer battery applications, $LiFePO_4$/solid polymer electrolyte (SPE)/Li and $LiFePO_{4}-TiO_{2}/SPE/Li$ cells were characterized by a cyclic voltammetry and charge/discharge cycling. The electrode with $LiFePO_{4}-carbon-TiO_{2}$ in PVDF-PC-EC-$LiClO_{4}$ electrolyte showed promising capacity of above 100 mAh/g at 1C rate.

Bio-accumulation of 210Pb and 210Po within the Trophic Level of Phytoplankton-Zooplankton-Anchovy-Mackerel in the Coastal Water of the Jeju Island, Korea (제주도 근해 식물플랑크톤-동물플랑크톤-멸치-고등어 영양단계에서 210Pb과 210Po의 생물농축)

  • Cho, Boeun;Kim, Suk Hyun
    • Ocean and Polar Research
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    • v.38 no.2
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    • pp.139-148
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    • 2016
  • The activity concentrations of $^{210}Po$ and $^{210}Pb$ within phytoplankton-zooplankton-anchovy-mackerel in the coastal water of the Jeju Island were determined to understand their distribution and bio-accumulation along the trophic level. In the surface water, the total activity concentrations of $^{210}Po$ and $^{210}Pb$ were $0.83{\pm}0.004mBq\;kg^{-1}$ and $1.27{\pm}0.03mBq\;kg^{-1}$. And the dissolved activity concentration of $^{210}Po$ and $^{210}Pb$ were $0.75{\pm}0.06mBq\;kg^{-1}$ and $1.22{\pm}0.09mBq\;kg^{-1}$ respectively. In the phytoplankton, the concentration factor (CF) of $^{210}Po$ and $^{210}Pb$ were $1.5{\times}10^5$ and $2.6{\times}10^4$ shows $^{210}Po$ is 5 times higher compared to $^{210}Pb$. The similar CF factor in the zooplankton of $^{210}Po$ was derived as $1.4{\times}10^5$. The CF of $^{210}Po$ in anchovy was increased twice compared to that in plankton. This is the evidence that there is $^{210}Po$ bio-magnification in the trophic level of plankton-anchovy. However the $^{210}Po$ activity concentration in the muscle tissue of mackerel was one-hundred times lower than that in anchovy. This reflects that in the trophic level of anchovy-mackerel, the bio-accumulation of $^{210}Po$ is decreased. The activity concentrations of $^{210}Po$ in the internal organs of anchovy and mackerel were 8 to 38 times higher than those in muscle tissues. In phytoplankton-zooplankton-anchovy, the CF of $^{210}Pb$ was decreased five times along the trophic level in order. In anchovy-mackerel it was decreased by 30-70%.

Synthesis and Electrochemical Properties of Li3V2(PO4)3-LiMnPO4 Composite Cathode Material for Lithium-ion Batteries

  • Yun, Jin-Shik;Kim, Soo;Cho, Byung-Won;Lee, Kwan-Young;Chung, Kyung Yoon;Chang, Wonyoung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.433-436
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    • 2013
  • Carbon-coated $Li_3V_2(PO_4)_3-LiMnPO_4$ composite cathode materials are first reported in this work, prepared by the mechanochemical process with a complex metal oxide as the precursor and sucrose as the carbon source. X-ray diffraction pattern of the composite material indicates that both olivine $LiMnPO_4$ and monoclinic $Li_3V_2(PO_4)_3$ co-exist. We further investigated the electrochemical properties of our $Li_3V_2(PO_4)_3-LiMnPO_4$ composite cathode materials using galvanostatic charging/discharging tests, where our $Li_3V_2(PO_4)_3-LiMnPO_4$ composite electrode materials exhibit the charge/discharge efficiency of 91.9%, while $Li_3V_2(PO_4)_3$ and $LiMnPO_4$ exhibit the efficiency of 87.7 and 86.7% in the first cycle. The composites display unique electrochemical performances in terms of overvoltage and cycle stability, displaying a reduced gap of 141.6 mV between charge and discharge voltage and 95.0% capacity efficiency after $15^{th}$ cycles.