• Title/Summary/Keyword: 볼타전지

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Analysis of Voltaic Cell Described in the Science Textbooks of Secondary Schools (중·고등학교 과학 교과서에 제시된 볼타전지에 대한 문제점 분석)

  • Sin, Dong-Hyeok;Lee, Sang-Gwon;Choe, Byeong-Sun
    • Journal of the Korean Chemical Society
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    • v.46 no.4
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    • pp.363-377
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    • 2002
  • The purpose of this study was to improve the problems of the voltaic cell described in the science textbooks of secondary schools. For this purpose, the contents of science textbooks which are related to the voltaic cell were analyzed and the problems which were not explained clearly by theorems were tried to be explained by experiments, and lastly sug-gestions were made toward the improvements regarding the voltaic cell in the science textbooks. The findings are that there are problems on the ways of ensuring whether the voltaic cell operates properly as a chemical battery, on the explanation of why the hydrogen bubbles form at the zinc electrode, on the cell potential, on the unification of the electrode terminology used, and on the mention of the current. Solutions to the problems except the cell potential were suggested. According to the experiment, the theoretical potential was calculated by considering the potentials of redox reactions at the two electrodes of the cell and by taking into account the characteristics of the electrodes such as the work function, ionization energy, stan-dard reduction potential, and electronegativity.The cell potential of the voltaic cell is explained by several factors. In the improved version of the textbook's introduction section to the voltaic cell, it is necessary to describe the voltaic cell his-torically.For the conceptual section, it should be explained in terms of the Daniel cell.

Modification of the Experimental Setup to reduce Misconceptions for the Voltaic Cell described in High School Chemistry Textbooks (고등학교 화학 교과서에 기술된 볼타 전지의 오개념을 줄이기 위한 실험 장치 개발)

  • Nak Han Jang;Kyung Ok Lee;Jin Seung Lee;Jung Sang Suh
    • Journal of the Korean Chemical Society
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    • v.47 no.1
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    • pp.79-86
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    • 2003
  • Misconceptions of students for a Voltaic cell were studied and their contents described in the high school chemistry II textbooks were analyzed. This study shows that students have many misconceptions and a few of chemistry textbooks contain some false description in a Voltaic cell. In the most textbooks, the reasons why the measured cell voltage of a Voltaic cell is near 1.1 V at the initial stage and then it decreases with time are not explained clearly. The emf of a Voltaic cell at a standard state is 0.76 V but in some textbooks it is described as 1.1 V of a Daniel cell. Even after learning the Voltaic cell or performing the experiment of textbooks, most students still have some misconceptions. These may be due to at least two following facts: the first is that the measured cell voltage of a Voltaic cell at the initial stage is very similar to that of a Daniel cell. The second is that the most experiment of a Voltaic cell is not performed under the condition of a standard state. Therefore, we have suggested a model of the modified experimental setup of a Voltaic cell that could reduce misconceptions of students.

A Study on the Characteristics of Shaft Electric Motive Force of Controllable Pitch Propeller - Focusing on the M/V Segero - (가변피치 프로펠러의 축기전력 특성에 관한 연구 - 세계로호를 중심으로 -)

  • Park, Kyung-Min;Im, Myeong-Hwan;Choe, Sang-Bom;Ahn, Byong-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.1
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    • pp.135-140
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    • 2022
  • Most machines are made of several types of . In particular, the shaft system of the ship consists of the brass of the propeller blade and the stainless steel of the shaft. When dissimilar the electrolyte solution of seawater, a voltaic cell and a shaft electromotive force is generated. This electromotive force causes electrical corrosion of the bearing and shaft supporting the shaft system. prevent this corrosion, a shaft grounding system is installed in ships. As for the experimental method, various information acquired by designing a program to periodically measure the electromotive force of the controllable pitchpropeller) system using an A/D converter of NI. This study analyzed the generation and characteristics of accumulator electromotive force for CPP and considered the installation location of the grounding system to remove the accumulator electromotive force.