• Journal of The Korean Association For Science Education
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• v.13 no.1
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• pp.48-55
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• 1993

In this study, kindergarten teachers' and secondary science teachers', total number of 117 in Taegu, images of scientists and their respected scientists were explored through the Draw-A-Scientists-Test and Network Analysis methods. Main results of the study can be summarized as follows: 1) Teachers, in general, showed some stereotyped images of scientists. But kindergarten teachers have more stereotyped ones than secondary science teachers do. 2) Teachers tended to respect some scientists through those scientists' personal characteristics, especially affective ones. But while kindergarten teachers seemed to consider scientists' contributions to society and their affective characteristis more important, secondary science teacher tendeded to consider scientists' contributions to science and their cognitive characteristics.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.710-714
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• 2006

Barium titanate nanoparticles were synthesized under N$_2$ atmosphere by the hydrolysis and condensation of barium hydroxide octahydrate and titanium (IV) isopropoxide. The synthesized particles were aggregates of nanosized primary particles. The primary particles of about 20-50 nm in diameter became building blocks of larger secondary particles, which are in most cases spherical in shape. The size and morphological evolution of secondary particles are strongly related to the precursor concentration. The observations suggest that formation and control of secondary particles is an essential step in the alkoxidehydroxide sol-precipitation process to obtain monodispersed barium titanate nanopowders.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.410-418
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• 2024

Study of flow behavior within rod bundles has been an active topic. Surface modification technologies are important parts of the design of the fourth generation reactor, which can increase the strength of the secondary flow within the rod bundle lattices. Quasi-periodic large-scale vortex structure (QLVS) is introduced by arranging micro ribs on the surface of rod bundles, which enhanced the scale of the secondary flow between the rod bundle lattices. Using computational fluid dynamics (CFD) and water experiments, the flow field distribution and drag coefficient of the rod-bundle lattices are studied. The secondary flow between the micro-ribbed rod-bundle lattice is significantly enhanced compared to the standard rod-bundle lattice. The numerical simulation results agree well with the experimental results.

• Journal of The Korean Association For Science Education
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• v.30 no.5
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• pp.636-646
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• 2010

The purpose of this study is to confirm secondary biology teachers' recognition about cell and gene concepts that should be taught in biology according to each school level and to classify the concepts into essential, optional and non-essential ones. We developed a questionnaire in consultation with 5 biology professors after selecting some biological concepts from some data about the recommendations of BSCS, biology, study for the connection with biological contents in each school level. This survey was conducted to biological teachers in secondary schools (146 individuals) from all over Korea for studying the concepts of the cell and gene in elementary and secondary schools. The results of this study revealed the following: The number of essential concepts in the cell and gene domain increases as the school levels go up. Moreover, secondary biology teacher recognized that there must be much more cell and gene concepts that should be taught in elementary and secondary schools compared to those suggested in the science curriculum and BSCS' recommendation.

• Progress in Medical Physics
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• v.27 no.3
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• pp.162-168
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• 2016

Proton therapy is increasingly being actively used in the treatment of cancer. In contrast to photons, protons have the potential advantage of delivering higher doses to the cancerous tissue and lower doses to the surrounding normal tissue. However, a range shifter is needed to degrade the beam energy in order to apply the pencil beam scanning technique to tumors located close to the minimum range. The secondary neutrons are produced in the beam path including within the patient's body as a result of nuclear interactions. Therefore, unintended side effects may possibly occur. The research related to the secondary neutrons generated during proton therapy has been presented in a variety of studies worldwide, since 2007. In this study, we measured the magnitude of the secondary neutron dose depending on the location of the detector and the use of a range shifter at the beam nozzle of the proton scanning mode, which was recently installed. In addition, the production of secondary neutrons was measured and estimated as a function of the distance between the isocenter and detector. The neutron dose was measured using WENDI-II (Wide Energy Neutron Detection Instruments) and a Plastic Water phantom; a Zebra dosimeter and 4-cm-thick range shifter were also employed as a phantom. In conclusion, we need to consider the secondary neutron dose at proton scanning facilities to employ the range shifter reasonably and effectively.

• Korean Journal of Materials Research
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• v.12 no.9
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• pp.712-717
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• 2002

New wet chemical method so called precipitation-evaporation method was suggested for preparing spinel structure lithium manganese oxide ($LiMn_2$$O_4$) for Li ion secondary battery. Using precipitation-evaporation method, $LiMn_2$$O_4$ cathode materials suitable for Li ion secondary batteries can be synthesized. Single spinel phase $LiMn_2$$O_4$ powder was synthesized at lower temperature compared to that of prepared by solid-state method. $LiMn_2$$O_4$ powder prepared by precipitation-evaporation method showed uniform, small size and well defined crystallinity particles. Li ion secondary battery using $LiMn_2$$O_4$ as cathode materials prepared by precipitation-evaporation method and calcined at $800^{\circ}C$ showed discharge capacity of 106.03mAh/g and discharge capacity of 95.60mAh/g at 10th cycle. Although Li ion secondary battery showed somewhat smaller initial capacity but good cyclic ability. It is suggested that electro-chemical properties can be improved by controlling particle characteristics by particle morphology modification during calcination and optimizing Li ion secondary battery assembly conditions.

• Journal of the Korean Society of Earth Science Education
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• v.11 no.2
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• pp.78-89
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• 2018

The purpose of this study is to explore ways to improve developing exam questions for Earth science education by analyzing exam trend of Earth science education in the secondary-school teacher employment test (TET, hereafter). For this purpose, we developed an analysis framework to analyze items of Earth science education in the secondary-school TET, and this analysis framework covers required courses for 'theory of Earth science education' of 'Earth science teaching certificate courses'. The analysis framework consists of big categories, assessment domains, and assessment components. We divided system changes in secondary-school TET into 4 types, and analyzed exams of 2014-2018 school year, which is the existing exam system. According to the results, 22-24 points out of 80 have been allotted to Earth science education. Among assessment domains, Earth science Teaching & Learning domain has taken the highest percentage of scores and item numbers, followed by Earth science inquiry, history & philosophy of science, etc. For each domain, we analyzed exam tendencies in detail. Based the results, we suggested ways to improve developing exam questions for Earth science education in the secondary-school TET, and ways to improve curriculum for Earth science education in the teacher education program.

• Journal of the Korean Chemical Society
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• v.46 no.6
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• pp.561-568
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• 2002

This study examined secondary school science teachers' thinking on physical and chemical change. For this research, we analysed the answers of 80 secondary school science teachers. According to the result of the analysis,teachers had various opinions when they classified phenomena of dissolving ionic compound or diluting acid into phys-ical change and chemical change. Many teachers tended to classify similar phenomena into different change when those were represented with different focus. It means that teachers' opinions were not consistent.

• Journal of Engineering Education Research
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• v.21 no.2
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• pp.17-27
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• 2018

This study aims to investigate the effect of design thinking-based STEAM program for primary and secondary students. The design thinking-based STEAM program dealt with advanced scientific technology issues and it consisted of 8 topics. A questionnaire was developed to explore the change of Science concept awareness, Interest, Self-efficacy, Career consciousness of students through the program. The questionnaire consisted of following 4 areas, such as 'Science concept awareness', 'Interest', 'Career consciousness' and 'Self efficacy'. Pre-post test was conducted to 75 primary and secondary students. As a result of analyzing post-test compared to pre-test, 'Science concept awareness', 'Career consciousness' and 'Self efficacy' of students were improved. And the 'Interest' wasn't changed significantly. Through this research, it can be suggested that the design thinking-based STEAM program can be useful at school education to improve the Science concept awareness, Career consciousness and Self-efficacy of primary and secondary students. It is also proposed that further research of the various areas of interest and other affective variables will be needed.

• Journal of The Korean Association For Science Education
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• v.15 no.1
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• pp.73-79
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• 1995

The purpose of this study was to investigate Korean secondary school students' perceptions of science and technology related social problems and STS education to ascertain the extent to which the current science programs incorporate STS themes. Students indicated that STS related problems or STS issues were given little attention in their science classes, even though they believed that studying those problems would be important. Results of the study support the contention of need for more attention to the implementation of STS themes into current Korean science education.