산수교구 개발에 관한 연구

전구호 공주교육대학교 초등연구원 1974 公州敎大論叢 Vol.11 No.-

As the attitude of our teachers, naturally we are concerned with manufacture anp utilization of teaching instrument for the true education, and it is natural for teachers to do our best for them. The writer thinks that teaching instrument are indispensable to make right result in teaching or guidance of learning activities, and it seems that originative manu- facture of teaching instrument is composed of the core of excellent teaching or guidance of learning activities. Summarizing this thesis, the writer refers to new outlook-on-teaching instrument, and thinks on many respects of development, on this, the writer takes an important case of teaching-instrument-development. The writer hopes that this thesis becomes the opportunty to be enthusiastic about teacher’s teaching-instrument-manufacture.

산수교육의 관점변천에 관한 고찰

전구호 공주교육대학교 초등연구원 1976 公州敎大論叢 Vol.13 No.1

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수리적 사고에 관한 소고

전구호 공주교육대학교 초등연구원 1976 公州敎大論叢 Vol.12 No.2

Not by accurate mathematical thinking, and desirable teaching or guidance of learn- ing activities in mathematics can’t be attained. So, studying throughly about mathematical thinking, the writer intends to express it’s figure. Analyzing mathematical thinking and dividing it into logical, general and analogical thinking, the writer thought about each of them. We teachers center on anticipating man’s infinite creative probability and developing thinking in teaching or guidance of mathematical learning activities.

위상교재의 지도에 관한 연구

전구호 공주교육대학교 초등연구원 1968 公州敎大論叢 Vol.5 No.-

1. Purpose The purpose of this survey was anaysis of the elements of topological materials, and' investigation of the realities of teaching and the results o£ them, therefore to obtain referen- tial materials for desirable and right teaching. 2. Research method (1). The investigator analyzed textbooks and drew out the topological materials from them, (2). investigated teachers' chief aim in real teaching with a questionarie made by investigator concidering analyzed elements and examples in national textbooks, (3). mea- sured the children’s understanding on topology by using questions which were chosen from national textbooks and arranged by the investigator. (4). The data was collected from five schools in Choong Chung-Nam-Do(province) Chosen by stratified sampling. In sampling, Choong Chang-Nam-Do was seperated into five parts east, west, south, north, middle part, and a school was chosen in each part, the questionarie was given to all teachers in each school, and the questions to all children. 3. Summary (1) . It was found that the conceptions (general ideas) of topoloy were introduced to the lower grades in elementary school. The conceptions and the level of contents of topolgy must be clear in accordance with grade. It would be better that the charateristics of close-curve open-curve and the conception of homeomorphic are introduced in lower grade. (2) . It was found that the teachers were in want of the knowledge on conceptions of topology, and the degree of children’s understanding had close relation to teacher’s chief aim on teaching. without exact knowledge and enough understanding it is inpossible to teach others. 4. Suggestions Education of new mathematics needs new contents and new methods. First teachers have to try to master new mathematics. Second the administration authorities and the institution of in-service education have to surport re-education of teachers.

초등 교육 발전에 기여하는 교육대학의 현장지도 역할에 관한 연구

김성회 / 이종철 / 전구호 / 정용팔 / 최동준 / 문낙주 공주교육대학교 초등연구원 1977 公州敎大論叢 Vol.13 No.2

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Corrosion Behavior of Stainless Steel 316 for Carbon Anode Oxide Reduction Application

Jeon, Min Ku,Kim, Sung-Wook,Choi, Eun-Young Korean Radioactive Waste Society 2020 방사성폐기물학회지 Vol.18 No.2

Here, the stability of stainless steel 316 (SS-316) was investigated to identify its applicability in the oxide reduction process, as a component in related equipment, to produce a complicated gas mixture composed of O₂ and Cl₂ under an argon (Ar) atmosphere. The effects of the mixed gas composition were investigated at flow rates of 30 mL/min O₂, 20 mL/min O₂ + 10 mL/min Cl₂, 10 mL/min O₂ + 20 mL/min Cl₂, and 30 mL/min Cl₂, each at 600℃, during a constant argon flow rate of 170 mL/min. It was found that the corrosion of SS-316 by the chlorine gas was suppressed by the presence of oxygen, while the reaction proceeded linearly with the reaction time regardless of gas composition. Surface observation results revealed an uneven surface with circular pits in the samples that were fed mixed gases. Thermodynamic calculations proposed the combination of Fe and Ni chlorination reactions as an explanation for this pit formation phenomenon. An exponential increase in the corrosion rate was observed with an increase in the reaction temperature in a range of 300 ~ 600℃ under a flow of 30 mL/min Cl₂ + 170 mL/min Ar.

Preliminary Study on Chlorination Reaction of Lithium Carbonate for Carbon-Anode-Based Oxide Reduction Applications

Jeon, Min Ku,Kim, Sung-Wook,Choi, Eun-Young Korean Radioactive Waste Society 2021 방사성폐기물학회지 Vol.19 No.2

The reaction between Li₂CO₃ and Cl₂ was investigated to verify its occurrence during a carbon-anode-based oxide reduction (OR) process. The reaction temperature was identified as a key factor that determines the reaction rate and maximum conversion ratio. It was found that the reaction should be conducted at or above 500℃ to convert more than 90% of the Li₂CO₃ to LiCl. Experiments conducted at various total flow rate (Q) / initial sample weight (W_i) ratios revealed that the reaction rate was controlled by the Cl₂ mass transfer under the experimental conditions adopted in this work. A linear increase in the progress of reaction with an increase in Cl₂ partial pressure (pCl₂) was observed in the pCl₂ region of 2.03-10.1 kPa for a constant Q of 100 mL·min^-1 and W_i of 1.00 g. The results of this study indicate that the reaction between Li₂CO₃ and Cl₂ is fast at 650℃ and the reaction is feasible during the OR process.

Recycling of Li₂ZrO₃ as LiCl and ZrO₂ via a Chlorination Technique

Jeon, Min Ku,Kim, Sung-Wook,Lee, Keun-Young,Choi, Eun-Young Korean Radioactive Waste Society 2021 방사성폐기물학회지 Vol.19 No.2

In this study, a chlorination technique for recycling Li₂ZrO₃, a reaction product of ZrO₂-assisted rinsing process, was investigated to minimize the generation of secondary radioactive pyroprocessing waste. It was found that the reaction temperature was a key parameter that determined the reaction rate and maximum conversion ratio. In the temperature range of 400-600℃, an increase in the reaction temperature resulted in a profound increase in the reaction rate. Hence, according to the experimental results, a reaction temperature of at least 450℃ was proposed to ensure a Li₂ZrO₃ conversion ratio that exceeded 80% within 8 h of the reaction time. The activation energy was found to be 102 ± 2 kJ·mol^-1·K^-1 between 450 and 500℃. The formation of LiCl and ZrO₂ as reaction products was confirmed by X-ray diffraction analysis. The experimental results obtained at various total flow rates revealed that the overall reaction rate depends on the Cl₂ mass transfer rate in the experimental condition. The results of this study prove that the chlorination technique provides a solution to minimize the amount of radioactive waste generated during the ZrO₂-assisted rinsing process.

Corrosion Behavior of Hastelloy C-276 for Carbon-anode-based Oxide Reduction Applications

Jeon, Min Ku,Kim, Sung-Wook,Choi, Eun-Young Korean Radioactive Waste Society 2020 방사성폐기물학회지 Vol.18 No.3

The corrosion behavior of Hastelloy C-276 was investigated to identify its applicability for carbon-anode-based oxide reduction (OR), in which Cl₂ and O₂ are simultaneously evolved at the anode. Under a 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar flow, the corrosion rate was less than 1 g·m^-2·h^-1 up to 500℃, whereas the rate increased exponentially from 500 to 700℃. The effects of the Cl₂-O₂ composition on the corrosion rate at flow rates of 30 mL·min^-1 Cl₂, 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂, and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ with a constant 170 mL·min^-1 Ar flow rate at 600℃ was analyzed. Based on the data from an 8 h reaction, the fastest corrosion rate was observed for the 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ case, followed by 30 mL·min^-1 Cl₂ and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂. The effects of the chlorine flow rate on the corrosion rate were negligible within the 5-30 mL·min^-1 range. A surface morphology analysis revealed the formation of vertical scratches in specimens that reacted under the Cl₂-O₂ mixed gas condition.

Effect of heat treatment on PtRu/C catalyst for methanol electro-oxidation

Jeon, Min Ku,Lee, Ki Rak,Jeon, Hee Jung,Woo, Seong Ihl Springer-Verlag 2009 Journal of applied electrochemistry Vol.39 No.9