• 제목/요약/키워드: cell cycles

검색결과 533건 처리시간 0.042초

The Electrochemical Properties of $Li_xNi_{2-x}O_2$ prepared by Heat Treatment of LiOH and $Ni(OH)_2$ (LiOH와 $Ni(OH)_2$의 열처리에 의해 제조된 $Li_xNi_{2-x}O_2$의 전기화학적 특성)

  • Lim, S.H.;Lee, J.Y.;Yoon, S.S.;Son, J.I.;Gu, H.B.
    • Proceedings of the KIEE Conference
    • /
    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
    • /
    • pp.224-226
    • /
    • 1996
  • The purpose of this study is to research and develop $Li_xNi_{2-x}O_2$ cathode for lithium rechargeable battery. We investigated XRD, cyclic voltammetry, AC impedance response and charge/discharge cycling of $Li_xNi_{2-x}O_2$/Li cells. The cell resistance was decreased much at initial charge process from 100% SOC to 0% SOC. The discharge capacity based on $Li_xNi_{2-x}O_2$ of 1st and 15th cycles was 135mAh/g and 108mAh/g, respectively. The $Li_xNi_{2-x}O_2$/Li cell had a good properties.

  • PDF

The Effect of Repetitive Compression on the Fatigue Properties of Foam for Footwear Mid-sole (반복압축이 스포츠화용 발포체의 피로특성에 미치는 영향)

  • Park, Cha-Cheol
    • Elastomers and Composites
    • /
    • 제40권4호
    • /
    • pp.242-248
    • /
    • 2005
  • To study the fatigue properties of three type of foams for footwear midsole, polyurethane(PU), phylon(PH) and injection phylon(IP) foams were prepared with different hardnesses. Three types of foams were repetitively compressed for 50,000 cycles at 50 rpm. Cell shapes of foams were deformed with repetitive compression. The extent of cell deformation of IP was larger than those of PH and PU. Permanent strain of foam was made by repetitively compressing the foam, and the extent of IP was larger than those of PU and PH. Maximum compression forces of three types of the foams were decreased with the repetitive compression, and IP had the largest decrease in compression load of foam with compression. Decreases in maximum compression force of three types of foams were increased with increase of the hardness of foam.

Pneumocystis Pneumonia Developing during Treatment of Recurrent Renal Cell Cancer with Nivolumab (니볼루맙 치료 도중 발생한 폐포자충 폐렴 1예)

  • Kim, Hak Ro;Keam, Bhumsuk;Park, Young Sik;Kim, Miso;Kim, Tae Min;Kim, Dong-Wan;Heo, Dae Seog
    • The Korean Journal of Medicine
    • /
    • 제93권6호
    • /
    • pp.571-574
    • /
    • 2018
  • Nivolumab is an immune checkpoint inhibitor approved for the treatment of metastatic cancers. Here, we report the case of a 65-year-old male with recurrent renal cell carcinoma. After six cycles of nivolumab treatment, positron emission tomography/computed tomography (PET/CT) was performed to evaluate the response. PET/CT revealed diffuse ground glass opacities in both lungs. He developed a cough, sputum, chills, and a febrile sense. After bronchoscopic bronchoalveolar lavage, pneumocystis pneumonia was finally diagnosed.

A Separator with Activated Carbon Powder Layer to Enhance the Performance of Lithium-Sulfur Batteries

  • Vu, Duc-Luong;Lee, Jae-Won
    • Journal of Powder Materials
    • /
    • 제25권6호
    • /
    • pp.466-474
    • /
    • 2018
  • The high theoretical energy density ($2600Wh\;kg^{-1}$) of Lithium-sulfur batteries and the high theoretical capacity of elemental sulfur ($1672mAh\;g^{-1}$) attract significant research attention. However, the poor electrical conductivity of sulfur and the polysulfide shuttle effect are chronic problems resulting in low sulfur utilization and poor cycling stability. In this study, we address these problems by coating a polyethylene separator with a layer of activated carbon powder. A lithium-sulfur cell containing the activated carbon powder-coated separator exhibits an initial specific discharge capacity of $1400mAh\;g^{-1}$ at 0.1 C, and retains 63% of the initial capacity after 100 cycles at 0.2 C, whereas the equivalent cell with a bare separator exhibits a $1200mAh\;g^{-1}$ initial specific discharge capacity, and 50% capacity retention under the same conditions. The activated carbon powder-coated separator also enhances the rate capability. These results indicate that the microstructure of the activated carbon powder layer provides space for the sulfur redox reaction and facilitates fast electron transport. Concurrently, the activated carbon powder layer traps and reutilizes any polysulfides dissolved in the electrolyte. The approach presented here provides insights for overcoming the problems associated with lithium-sulfur batteries and promoting their practical use.

Electrochemical Performance of High-Voltage LiMn0.8Fe0.2PO4 Cathode with Polyacrylonitrile (PAN)-Based Gel Polymer Electrolyte

  • Kwon, O. Hyeon;Kim, Jae-Kwang
    • Korean Chemical Engineering Research
    • /
    • 제57권4호
    • /
    • pp.547-552
    • /
    • 2019
  • Electrochemical properties of $LiMn_{0.8}Fe_{0.2}PO_4$ cathode were investigated with gel polymer electrolyte (GPE). To access fast and efficient transport of ions and electrons during the charge/discharge process, a pure and well-crystallized $LiMn_{0.8}Fe_{0.2}PO_4$ cathode material was directly synthesized via spray-pyrolysis method. For high operation voltage, polyacrylonitrile (PAN)-based gel polymer electrolyte was then prepared by electrospinning process. The gel polymer electrolyte showed high ionic conductivity of $2.9{\times}10^{-3}S\;cm^{-1}$ at $25^{\circ}C$ and good electrochemical stability. $Li/GEP/LiMn_{0.8}Fe_{0.2}PO_4$ cell delivered a discharge capacity of $159mAh\;g^{-1}$ at 0.1 C rate that was close to the theoretical value ($170mAh\;g^{-1}$). The cell allows stable cycle performance (99.3% capacity retention) with discharge capacity of $133.5mAh\;g^{-1}$ for over 300 cycles at 1 C rate and exhibits high rate-capability. PAN-based gel polymer is a suitable electrolyte for application in $LiMn_{0.8}Fe_{0.2}PO_4/Li$ batteries with perspective in high energy density and safety.

Study on the Fabrication of Tunnel Type $E^2PROM$ and Its Characteristics (터널링형 $E^2PROM$ 제작 및 그 특성에 관한 연구)

  • Kim, Jong Dae;Kim, Sung Ihl;Kim, Bo Woo;Lee, Jin Hyo
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • 제23권1호
    • /
    • pp.65-73
    • /
    • 1986
  • Experiment have been conducted about thin oxide characteristics according to O2/N2 ratio needed for EEPROM cell fabrication. As a result, we think that there is no problem even if we grow oxide layer with large O2/N2 ratio and short exidation time and when the water is implated by As before oxidation, the oxide breakdown field is about IMV/cm lower than that is not implanted. Especially, the thin oxide characteristic seems to be affected largely by wafer cleaning and oxidation in air. On the basis of these, tunnel type EEPROM cell is fabricated by 3um CMOS process and its characteristic is studied. Tunnel oxide thickness(100\ulcorner is chosen to allow Fowler-Nordheim tunneling to charge the floating gate at the desired programming voltage and tunnel area(2x2um\ulcorneris chosen to increase capacitive coupling ratio. For program operation, high voltage (20-22V) is applied to the control gate, while both drain and source are gdrounded. The drain voltage for erase is 16V. It is shown that charge retention characteristics is not limited by leakage in the oxide and program/erase endurance is over 10E4 cycles of program erase operation.

  • PDF

Glycogen Phosphorylase Inhibitor Promotes Hair Growth via Protecting from Oxidative-Stress and Regulating Glycogen Breakdown in Human Hair follicles

  • Bomi Park;Daeun Kim;Hairu Zhao;SoonRe Kim;Byung Cheol Park;Sanghwa Lee;Yurim Lee;Hee Dong Park;Dongchul Lim;Sunyoung Ryu;Jae Sung Hwang
    • Biomolecules & Therapeutics
    • /
    • 제32권5호
    • /
    • pp.640-646
    • /
    • 2024
  • Hair growth cycles are mainly regulated by human dermal papilla cells (hDPCs) and human outer root sheath cells (hORSCs). Protecting hDPCs from excessive oxidative stress and hORSCs from glycogen phosphorylase (PYGL) is crucial to maintaining the hair growth phase, anagen. In this study, we developed a new PYGL inhibitor, hydroxytrimethylpyridinyl methylindolecarboxamide (HTPI) and assessed its potential to prevent hair loss. HTPI reduced oxidative damage, preventing cell death and restored decreased level of anagen marker ALP and its related genes induced by hydrogen peroxide in hDPCs. Moreover, HTPI inhibited glycogen degradation and induced cell survival under glucose starvation in hORSCs. In ex-vivo culture, HTPI significantly enhanced hair growth compared to the control with minoxidil showing comparable results. Overall, these findings suggest that HTPI has significant potential as a therapeutic agent for the prevention and treatment of hair loss.

Temporal Expression of RNA Polymerase II in Porcine Oocytes and Embryos

  • Oqani, Reza;Lee, Min Gu;Tao, Lin;Jin, Dong Il
    • Reproductive and Developmental Biology
    • /
    • 제36권4호
    • /
    • pp.237-241
    • /
    • 2012
  • Embryonic genome activation (EGA) is the first major transition that occurs after fertilization, and entails a dramatic reprogramming of gene expression that is essential for continued development. Although it has been suggested that EGA in porcine embryos starts at the four-cell stage, recent evidence indicates that EGA may commence even earlier; however, the molecular details of EGA remain incompletely understood. The RNA polymerase II of eukaryotes transcribes mRNAs and most small nuclear RNAs. The largest subunit of RNA polymerase II can become phosphorylated in the C-terminal domain. The unphosphorylated form of the RNA polymerase II largest subunit C-terminal domain (IIa) plays a role in initiation of transcription, and the phosphorylated form (IIo) is required for transcriptional elongation and mRNA splicing. In the present study, we explored the nuclear translocation, nuclear localization, and phosphorylation dynamics of the RNA polymerase II C-terminal domain in immature pig oocytes, mature oocytes, two-, four-, and eight-cell embryos, and the morula and blastocyst. To this end, we used antibodies specific for the IIa and IIo forms of RNA polymerase II to stain the proteins. Unphosphorylated RNA polymerase II stained strongly in the nuclei of germinal vesicle oocytes, whereas the phosphorylated form of the enzyme was confined to the chromatin of prophase I oocytes. After fertilization, both unphosphorylated and phosphorylated RNA polymerase II began to accumulate in the nuclei of early stage one-cell embryos, and this pattern was maintained through to the blastocyst stage. The results suggest that both porcine oocytes and early embryos are transcriptionally competent, and that transcription of embryonic genes during the first three cell cycles parallels expression of phosphorylated RNA polymerase II.

Comparative investigation of endurance and bias temperature instability characteristics in metal-Al2O3-nitride-oxide-semiconductor (MANOS) and semiconductor-oxide-nitride-oxide-semiconductor (SONOS) charge trap flash memory

  • Kim, Dae Hwan;Park, Sungwook;Seo, Yujeong;Kim, Tae Geun;Kim, Dong Myong;Cho, Il Hwan
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • 제12권4호
    • /
    • pp.449-457
    • /
    • 2012
  • The program/erase (P/E) cyclic endurances including bias temperature instability (BTI) behaviors of Metal-$Al_2O_3$-Nitride-Oxide-Semiconductor (MANOS) memories are investigated in comparison with those of Semiconductor-Oxide-Nitride-Oxide-Semiconductor (SONOS) memories. In terms of BTI behaviors, the SONOS power-law exponent n is ~0.3 independent of the P/E cycle and the temperature in the case of programmed cell, and 0.36~0.66 sensitive to the temperature in case of erased cell. Physical mechanisms are observed with thermally activated $h^*$ diffusion-induced Si/$SiO_2$ interface trap ($N_{IT}$) curing and Poole-Frenkel emission of holes trapped in border trap in the bottom oxide ($N_{OT}$). In terms of the BTI behavior in MANOS memory cells, the power-law exponent is n=0.4~0.9 in the programmed cell and n=0.65~1.2 in the erased cell, which means that the power law is strong function of the number of P/E cycles, not of the temperature. Related mechanism is can be explained by the competition between the cycle-induced degradation of P/E efficiency and the temperature-controlled $h^*$ diffusion followed by $N_{IT}$ passivation.

A Phase II Study on Continuous Infusional Paclitaxel and 5-Fu as First-line Chemotherapy for Patients with Advanced Esophageal Cancer

  • Gu, Ming;Li, Su-Yi;Huang, Xin-En;Lin, Yan;Cheng, Hong-Yan;Liu, Lin
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제13권11호
    • /
    • pp.5587-5591
    • /
    • 2012
  • Objective: This study was performed to evaluated the efficacy and safety of continuous infusional paclitaxel and 5-Fu as first-line chemotherapy in patients with advanced esophageal squamous cell cancer (ESCC). Methods: A total of 22 patients with advanced esophageal squamous cell cancer with no indications for surgery and radiation therapy, or recurrent patients were enrolled from October 2008 to November 2010. All were treated with PTX 20 $mg/m^2$ was administered through a 16 hours continuous intravenous infusion on days 1 to 3, 8 and 9. DDP 3.75 $mg/m^2$ was given on days 1 to 4 and 8 to 11, continuous infusional 5-FU over 24-hours on days 1 to 5 and 8 to 12 at a dose of 375 $mg/m^2$, and folacin 60 mg orally synchronized with 5-Fu. The treatment was repeated every 21 days for at least two cycles. Results: 22 cases of all enrolled patients could be evaluated for the effect of treatment: 2 cases were CR, 9 cases PR, 5 cases SD and 2 cases PD, giving an overall response rate of 68.2%(15/22). The median time to progression was 7.0 months. The adverse reactions related to chemotherapy were tolerable; the most common toxic effects were marrow depression, alopecia, and fatigue. Conclusion: Low-dose continuous infusional PTX over 16-hours and 5-fu over 24-hours is a promising regimen with good tolerability in treating patients with advanced esophageal squamous cell cancer.