• Title/Summary/Keyword: chemistry problem solving

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Low Temperature Pyrolysis for the Recovery of Value-added Resources from Waste Wire (II) (폐전선으로부터 유가자원 회수를 위한 저온열분해(II))

  • Han, Seong-Kuk;Kim, Jae-Yong
    • Applied Chemistry for Engineering
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    • v.20 no.5
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    • pp.553-556
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    • 2009
  • This research aims at the recovery of valuable resource and more efficient waste treatment through solving the problem of pyrolysis technique. At first, in order to raise the economical efficiency, the low temperature pyrolysis experiment was carried out at the temperature of $450^{\circ}C$, which is lower than the common pyrolysis temperature area ($500{\sim}1000^{\circ}C$). We could lower the reaction temperature and reduce the reaction time by using catalyst. Also we used indirect heat for the purpose of maintaining favorable anoxic condition. As a result, we could raise the recovery rate of the valuable copper and synthetic fuel oil. Furthermore, the by-products and flue gas could be treated more effectively as well. The flue gas passed through two stage neutralization tank, so that dioxin hardly occurs and other environment items are controlled fairly well to the environmental standard. Throughout this study, we produced the low temperature pyrolysis equipment (GTPK-001) as mentioned above, and we found out that the technique can be commercialized economically as well as environmentally friendly.

Using Online Knowledge-based Search Service in Science Education: focused on Secondary School Chemistry (과학교육에서의 온라인 지식검색 서비스 활용 현황과 역할: 중·고등학교 화학교과를 중심으로)

  • Choi, Chui Im;Lee, Eun Ah;Kim, Miyun;Kim, Min Wook;Moon, Sung Hyun;Choi, Bokyung
    • Journal of Science Education
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    • v.36 no.1
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    • pp.49-55
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    • 2012
  • The purpose of this study is to examine how online knowledge-based search service is being used by students in science education. Reviewing information and summarizing data are important parts in scientific inquiry. As more and more information is available online, how to review and summarize online information for scientific inquiry also becomes an issue. In this study, we examined one of the popular online knowledge-based search services to see what kinds of information in secondary school chemistry are mostly sought and how reliable those information could be. The result indicated that users mostly seek scientific explanations and problem solving but about 30% of provided information appeared to be incorrect. It implicates that it is necessary to pay attention for teaching students how to obtain, evaluate, and communicate online information in science education to enhance students' ability for scientific inquiry.

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The Effects of Research Project Program on the Science Process Skills and Science-Related Attitudes of High School Students (과제연구 프로그램이 고등학생들의 과학 탐구능력 및 과학에 관련된 태도에 미치는 영향)

  • Jung, Hae-Young;Moon, Seong-Bae
    • Journal of the Korean Society of Earth Science Education
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    • v.7 no.3
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    • pp.293-302
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    • 2014
  • The purpose of this study is to investigate the effects of research project program of science process skills and science-related attitudes for high school students. This study were accompanied by 72 junior students of G High School who were reorganized as students whose research subject was closely related to chemistry. These students went through 28 periods of 14 sessions of research project program, were tested before and after the study on their science process skills and science-related attitudes. A simple questionnaire afterwards to get their thoughts on this program, was surveyed. The results are as follows. First, the research project program was effective in the science process skills (p<0.01). There was a statistically meaningful difference in the subcategory of deduction, setting up hypotheses, finding variables, building experiments, graphing and interpreting data. Although there was an increase in the average scores of prediction, operant definition, and generalization factors, it was not statistically meaningful (p>0.05). Second, the research project program showed an increase in the post-test of the science-related attitudes but was not statistically meaningful (p>0.05). In terms of subcategoty, the social importance of science, criterion of scientists, application of scientific attitude, and enjoyment of science classes were statistically meaningful (p<0.05). Third, according to the survey of research project program, there was an increase in creating a research problem and solving it by oneself as well as in participating with other teammates to solve a problem. But the most difficult thing was when the experiment failed during the research was processing. The curiosity and interest, towards objects around all lives and science classes after the program done, were increased.

Case Study on Verbal Interactions of Teacher-Small Group Students in Science Experiments (과학 실험에서 교사-모둠학생의 언어적 상호작용 사례연구)

  • Seong, Suk-Kyoung;Choi, Byung-Soon
    • Journal of the Korean Chemical Society
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    • v.51 no.4
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    • pp.375-386
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    • 2007
  • The purpose of this study is to investigate the aspects of verbal interactions of teacher?small group students by categorizing those interactions which affect students' thinking thus to improve teacher's interaction. First, verbal interactions of teacher-small group students were divided into two categories ?Behaviors related to problem-solving, and Others. Behaviors related to problem-solving were also classified into two elements?Receiving opinion based on the students' thinking process, and Giving help based on the teacher's thinking process. Receiving opinion consists of agreement, question, correction, objection while giving help consists of information, hint, question, summary, and ask & answer. Most of teacher-small group students' interactions were in the form of teacher's questions and students' answers, and teacher's questions tended to require simple answers rather than answers from deep thought. In addition, there was a tendency that the teacher focused more on her own thinking process than students' and that she interacted with only a couple of students who gave correct answers. As a result, even after teacher's scaffolding, many students were often unable to understand the particular contents. However, through the interactions, the teacher made students to have confidence by restating their opinions and agreeing or praising them. She also created an atmosphere where students can give their opinions freely. From the observation of interactions, we can find that students' thinking process is affected by the characteristics of teacher's interactions such as expression of agreement and encouragement, hint giving rise to thought, interactions based on the students' thinking process, permission of students' activities and questions, allowing time for students' thought, and correction of wrong opinions. At this point, educational implications of teacher-small group students' interactions were drawn.

An Analysis of STS Contents in the High School Chemistry(II) Textbook (화학II 교과서의 STS 내용 분석)

  • Kim, Jung-Tae;Kim, Yun-Hi;Moon, Seong-Bae
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.90-96
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    • 2002
  • The STS contents, emphasized in the 6th curriculum, in the chemistry textbooks(II) were analyzed. The STS contents in textbooks showed average value of 2.7%. The chapter of ‘chemical bond and compound' were included 3.8% of STS contents. And the chapter of ‘atomic structure and periodic table', ‘state of material and solution', ‘science of material', and ‘chemical reaction' contained 3.2%, 2.2%, 1.9%, and 1.9% of STS contents, respectively. When the STS contents were analyzed by STS topics of Piel, the results are as follows; 33.7% on effect of technological developments, 27.5% on environmental quality and utilization of natural source, 19.6% on human engineering, 13.8% on energy, and 5.4% on sociality of science. However, there were no topics on population, space research and national defense. When the STS contents were analyzed by student activities of SATIS, most of the activities were research and case study. There were few field activities of practical investigation, problem solving and decision making, research design and stimulation. There were no activities of role play.

An Analysis of STS Contents in the General Science Textbooks(Chemistry Parts) of High School (공통과학 교과서 화학영역의 STS 내용 분석)

  • Choi, In Young;Kim, Yun Hi;Lee, Seok Hee;Moon, Seong Bae
    • Journal of the Korean Chemical Society
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    • v.45 no.3
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    • pp.256-263
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    • 2001
  • The STS contents, emphasized in the 6th curriculum, in the chemistry parts of general science textbooks were analyzed. The STS contents of textbooks showed average of 24.4%. The chapter in "modern science and technology" were included 45.5% in STS contents, 38.7% in "environment", 29.1% in energy, and 14.0% in "materials". When the STS contents were analyzed by STS topics of Piel, the results are as follows; 38.3% on environmental quality and utilization of natural source, 29.6% on effect of technological developments, 7.9% on energy, and 0.6% on human engineering. However, there were no topics on population, space research and national defense. When the STS contents were analyzed by student activities of SATIS, most of the activities were research and case study. There were few field activities of role play, problem solving and decision making, and research design.

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Longitudinal Study about Science Process Skills Item Forms Transition before and after Scholastic Ability Test for College (과학(科學) 탐구능력(探究能力) 평가(評價) 문항(問項) 유형(類型) 변화(變化)에 관(關)한 종단적(縱斷的) 연구(硏究))

  • Woo, Jong-Ok;Lee, Hang-Ro;Goo, Chang-Hyun
    • Journal of The Korean Association For Science Education
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    • v.16 no.3
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    • pp.314-328
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    • 1996
  • This study investigated the literature about science process skills' evaluation to analyse transition of evaluation objectives before and after a Scholastic Ability Test for College Entrance. In the literature survey the researcher established a 3 dimensional science assessment framework with X axis as science concept, Y axis as science process skills and Z axis as problem context. In order to analysis and compare each items the researcher selected 210 items from the 1st to the 7th trials and 138 items from the 1st to 4th Scholastic Ability Test for College Entrance and sampled 2873 science achievement test items from 10 high schools. In accordance with this taxonomy the researcher analysed and compared science process skills item forms. The following results were drawn : The items were evenly distributed in all the four areas(Earth Science, Biology, Physics and Chemistry) of the science concept domain, but they were heavily concentrated on data analysis and drawing a conclusion in science process domain. In the domain of problem context school context was the majority. In spite of distribution like this the ratio on science process skills measurement items and science achievement test items was increased after the Scholastic Ability Test for College Entrance was given. Also the ratio on item expression type was increased. Item form was almost 5 options selection type in the national level test. Although there were 4 options selection type, 5 options selection type, short answer type, essay type in school level test, rising from 33.1% to 65.5% on 5 options selection type is exhibited. This study showed that the school level item form was better various than the nation level. This point like this is the evidence for the improvement toward the science process skills test and influenced by Scholastic Ability Test for College Entrance. The ratio on the item which joined with the 3 axes had a mean of 99.3% in nation level test and mean 44.9% in school achievement test level. But the ratio in the school achievement test level increased after the Scholastic Ability Test for College Entrance was given. In view of this study we must furthermore study the item types which can evaluate valjdately science process skill's five stage each and evaluation method by the high school students' problem solving patterns and features in scientific inquiry on all science process skills elements.

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Development of the Instructional Model Emphasizing Discussion and the Characteristics of Verbal Interactions during its Implementation in a Science High School (과학고 토론수업을 위한 수업모형 개발과 적용과정에서 나타난 언어적 상호작용의 특징)

  • Kim, Hyun-Kyung;Choi, Byung-Soon
    • Journal of The Korean Association For Science Education
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    • v.29 no.4
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    • pp.359-372
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    • 2009
  • The purpose of this study was to develop the FPHER (problem finding, prediction & discussion, hands-on & experiment, explanation & arrangement, enrichment) instructional model emphasizing the social interactions, and as applied, characteristics of verbal interactions were examined overall and with each step. For this study, this model was applied to the students in 10th grade chemistry classes in a science high school, and their group verbal interactions were recorded and analyzed. The results of this study show that most verbal interactions were classified as on-task interactions in the FPHER instructional model, where suggestions were predominant to the acceptance of opinions. There were a few interactions in the F step, and there were many suggestions relating to the solutions and lacking in confidence in the P step. There were many suggestions relating to the process and orders in the H step. Also, there were many questions, some explanation and dissatisfaction, as well as a lack of confidence in the E step. There were many high-level interactions in the R step, and mainly interactions with worksheets showing high-level problem-solving abilities. More in-depth research is needed to develop the teaching strategies that can activate student-to-student interaction and student-teacher interaction with regard to instructions, enhancing thought as counter-argument, justification or sophistication, based on the instructional model in this study.

An Analysis of Characteristic and Factor about Middle School Science Descriptive Assessment Items (중학교 과학과 서술형 평가의 문항 특성 및 요인 분석)

  • Kim, Sungki;Choi, Eunju;Paik, Seounghey
    • Journal of the Korean Chemical Society
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    • v.59 no.5
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    • pp.445-453
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    • 2015
  • In 2005, descriptive assessment was introduced to increase students’ higher mental ability like problem-solving ability and creativity. Every year the ratio of descriptive assessment increases and it is regarded as an alternative evaluation to a multiple-choice item which measures simplicity knowledge. Externally the descriptive assessment took a root in school, but we can’t say definitely that it meets its original goal. In this paper, science descriptive assessment items of 5 middle schools in Gyeonggi-do were analysed; examiners was interviewed about how well they understood the characteristic of the assessment items. According to the analysis, characteristic of the items are ① unequal distribution of unit, ② difference of item’s type by unit, and ③ disappearance of measuring higher mental ability. It is considered that there are several factors of these characteristic - the lack of teachers’ ability to make assessment item; understanding of assessment instrument. These factors can be explained by the lack of assessment expertise. So the society’s effort is needed to raise teacher’s ability for the descriptive assessment.

Item Analysis for Selecting Science Gifted Middle School Students at Physics Class (과학영재교육원 중학교 물리 전공 선발 문항 분석)

  • Lim, Chun-Woo;Park, Yune-Bae
    • Journal of Gifted/Talented Education
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    • v.20 no.1
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    • pp.61-77
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    • 2010
  • The purpose of this study was to analyze the items that were used in entrance examination for science gifted education center for middle school students by using content analysis and classical item analysis. In content analysis, objective type items exhibited mathematics and physics were dominant. Science giftedness & creativity items were dominant. And essay type items consisted of physics items, have evaluated creative problem solving ability. Item difficulty and discrimination index, on the whole, were appropriate. Comparing with objective type, essay type has higher discrimination index. In correlation analysis between total score and score of each type of items, total score has the highest correlation with essay type items and science giftedness & creativity. It was recommended that mathematics, physics and chemistry items with focusing giftedness & creativity could give some implications for future selection methods of science gifted education center.