• Title, Summary, Keyword: Reversibility

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A Novel Sulphur Cathode Materials for Rechargeable Lithium Batteries

  • Jin, Bo;Park, Kyung-Hee;Gu, Hal-Bon
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.4
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    • pp.157-160
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    • 2007
  • Lithium-sulphur batteries were fabricated in a dry room, and their electrochemical properties were analyzed by scanning electron microscopy (SEM), cyclic voltammetry (CV), and charge-discharge tests. SEM results showed that sulphur and nanocarbon powders were mixed homogeneously, and sulphur powders were enwrapped by a large amount of carbon powders. The charge-discharge test results demonstrated that the lithium-sulphur battery displayed excellent reversibility and cycling performance, which supplied a discharge capacity of $788.1mAh\;g^{-1}$ at the first cycle and $796.4mAh\;g^{-1}$ after 71 cycles at room temperature, respectively.

High Hydrogen Capacity and Reversibility of K-Decorated Silicon Materials

  • Park, Min-Hee;Ryu, Seol;Han, Young-Kyu;Lee, Yoon-Sup
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1719-1721
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    • 2012
  • We have investigated the $H_2$ adsorption structures and binding energies of the metal (M)-doped (M = Li, Na, K, Mg, and Al) silicon complexes, $M-Si_{19}H_{11}$ and $M-Si_{24}H_{12}$, using density functional calculations. Alkali metals are preferred as doping elements because the Mg-Si and Al-$H_2$ interactions are weak. The maximum numbers of $H_2$ molecules that can be adsorbed are four and five for M=Li and K, respectively. We propose that the K-decorated silicon material might be an effective hydrogen storage material with high hydrogen capacity and high reversibility.

A Study in the Temporality in Digital Gameplay (디지털 게임 플레이의 시간성 연구)

  • Lee, Dong-Eun
    • Journal of Korea Game Society
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    • v.13 no.2
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    • pp.5-16
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    • 2013
  • The purpose of this study is how to occur the temporality in Digital Gameplay. There is two types of time in Gameplay. One is Irreversibility time that goes passed through a game world like a chronology order. Another is Reversibility time that returns and renews the time. The time's duality is caused by player's intervene and experience. And the polychronic temporality in gameplay makes the rhythm as replay and eternal cyclic time.

BAER SPECIAL RINGS AND REVERSIBILITY

  • Jin, Hai-Lan
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.4
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    • pp.531-542
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    • 2014
  • In this paper, we apply some properties of reversible rings, Baerness of fixed rings, skew group rings and Morita Context rings to get conditions that shows fixed rings, skew group rings and Morita Context rings are reversible. Moreover, we investigate conditions in which Baer rings are reversible and reversible rings are Baer.

An Analysis On Students' Misconceptions of the Reversibility of Irrational Functions (무리함수의 가역성에 대한 학생들의 오개념 분석)

  • Lee, Ki-Suk;Lee, Du-Ho
    • Communications of Mathematical Education
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    • v.24 no.3
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    • pp.709-730
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    • 2010
  • The inverse function of a one-to-one correspondence is explained with a graph, a numerical formula or other useful expressions. The purpose of this paper is to know how low achieving students understand the learning contents needed reversible thinking about irrational functions. Low achieving students in this study took paper-pencil test and their written answers were collected. They made various mistakes in solving problems. Their error types were grouped into several classes and identified in this analysis. Most students did not connected concepts that they learned in the lower achieving students to think in reverse order in case of and to visualize concepts of functions. This paper implies that it is very important to take into account students' accommodation and reversible thinking activity.

The Simplest Flowchart Stating the Mechanisms for Organic Xenobiotics-induced Toxicity: Can it Possibly be Accepted as a "Central Dogma" for Toxic Mechanisms?

  • Park, Yeong-Chul;Lee, Sundong;Cho, Myung-Haing
    • Toxicological Research
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    • v.30 no.3
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    • pp.179-184
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    • 2014
  • Xenobiotics causing a variety of toxicity in biological systems could be classified as two types, inorganic and organic chemicals. It is estimated that the organic xenobiotics are responsible for approximately 80~90% of chemical-induced toxicity in human population. In the class for toxicology, we have encountered some difficulties in explaining the mechanisms of toxicity caused especially by organic chemicals. Here, a simple flowchart was introduced for explaining the mechanism of toxicity caused by organic xenobiotics, as the central dogma of molecular biology. This flowchart, referred to as a central dogma, was described based on a view of various aspects as follows: direct-acting chemicals vs. indirect-acting chemicals, cytochrome P450-dependent vs. cytochrome P450-independent biotransformation, reactive intermediates, reactivation, toxicokinetics vs. toxicodynamics, and reversibility vs. irreversibility. Thus, the primary objective of this flowchart is to help better understanding of the organic xenobiotics-induced toxic mechanisms, providing a major pathway for toxicity occurring in biological systems.

Synthesis and Characterization of pH-sensitive and Self-oscillating IPN Hydrogel in a pH Oscillator (pH 진동계 안에서 pH 감응성 자기진동 IPN 하이드로젤의 합성과 분석)

  • Wang, Liping;Ren, Jie;Zhang, Xiaoyan;Yang, Xiaoci;Yang, Wu
    • Polymer Korea
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    • v.39 no.3
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    • pp.359-364
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    • 2015
  • A self-oscillating interpenetrating polymer network (IPN) poly(acrylic acid)/poly(ethylene glycol) (PAA/PEG) hydrogel was prepared by using radical polymerization with a two-step method. The IPN hydrogel was characterized by FTIR spectroscopy and morphological analysis. The results indicated that the chains of PEG and PAA twined to form porous structure which is beneficial to water molecules entering inside of the hydrogel. In addition, the pH-responsive behavior, salt sensitivity, swelling/de-swelling oscillatory behaviors and self-oscillation in a closed pH oscillator were also studied. The results showed that the prepared hydrogel exhibited pH-sensitivity, good swelling/de-swelling reversibility and excellent salt sensitivity. The self-oscillating behavior of swelling/de-swelling for the prepared hydrogel was caused by pH alteration coupled with the external media. This study may create a new possibility as biomaterial including new self-walking actuators and other related devices.

Study on the Development and Properties of Ceramics Restoration Purpose Urethane resin with Excellent Reversibility (가역성이 우수한 도자기 복원용 Urethane resin의 개발 및 물성에 대한 연구)

  • Oh, Seung Jun;Park, Gi Jung;Wi, Koang Chul
    • Journal of Conservation Science
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    • v.31 no.1
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    • pp.37-46
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    • 2015
  • In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.

Reversibility and safety of KISS1 metastasis suppressor gene vaccine in immunocastration of ram lambs

  • Han, Yan-Guo;Liu, Gui-Qiong;Jiang, Xun-Ping;Xiang, Xing-Long;Huang, Yong-Fu;Nie, Bin;Zhao, Jia-Yu;Nabeel, Ijaz;Tesema, Birhanu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.6
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    • pp.835-841
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    • 2018
  • Objective: The aim of this study was to investigate the reversibility and safety of KISS1 metastasis suppressor (KISS1) gene vaccine in immunocastration. Methods: Six eight-week old ram lambs were randomly divided into vaccinated and control groups. The vaccine (1 mg/ram lamb) was injected at weeks 0, 3, and 6 of the study. Blood samples were collected from the jugular vein before primary immunization and at weeks 2, 4, 6, 10, 14, 22, and 30 after primary immunization. All ram lambs were slaughtered at 38 weeks of age, and samples were collected. Results: The specific anti-KISS1 antibody titers in vaccinated animals were significantly higher and the serum testosterone level was significantly lower than those in the control groups from week 4 to 14 after primary immunization (p<0.05). No significant difference was observed at weeks 22 and 30 after the primary immunization. Similar results were also found for scrotal circumference, testicular weight, length, breadth, and spermatogenesis in seminiferous tubules in week 30 after primary immunization. KS (KISS1-hepatitis B surface antigen S) fusion fragment of KISS1 gene vaccine was not detected in host cell genomic DNA of 9 tissues of the vaccinated ram lambs by polymerase chain reaction. Conclusion: The effects of KISS1 gene vaccine in immunocastration were reversible and no integration events were recorded.