• Title/Summary/Keyword: Chemistry education

Search Result 2,010, Processing Time 0.023 seconds

Petrological and Mineralogical Characteristics of Amphibolite Used as Rock Bowl and Pot: Implications for Its Utility and Stability (음식 용기로 사용하는 각섬암의 암석-광물학적 특성: 그 효용성과 안정성에 대한 고찰)

  • Kim, Hyeong-Soo;Choi, Ho-Jeong
    • The Journal of the Petrological Society of Korea
    • /
    • v.17 no.3
    • /
    • pp.154-165
    • /
    • 2008
  • Rock bowls and pots used in restaurants are one of the popular usages of natural rocks in Korea. Most rock bowls and pots are made of Mg- and Ca-rich amphibolite composed of hornblende, actinolite, tremolite, diopside, plagioclase. Hornblende occurs as prismatic crystal habit, and belongs to Mg-hornblende to tschermakite. Actinolite and tremolite occur as acicular form (aspect ratio $0.10{\sim}0.13$), and ranges 0.65 to 0.90 in Mg/(Mg+Fe) ratio. These acicular actinolite and tremolite are non-asbestos minerals. However to use of rocks containing these minerals as tableware it is needed to regulatory guidelines for stability and utility based on petrological and mineralogical characteristics. Discrepancy of rock occurrence and mineral chemistry between commercial rock bowls and original rocks indicate that most rock bowls are made of uncertain amphibolite in original location. Consequently, there is a potential risk to use inappropriate amphibolites as tableware. Therefore, it is needed to systematically research on geology and biology, and manage commercial rock bowls and pots used in Korean restaurants.

The Effect of High School Research Project using the Science Writing Heuristic (탐구적 과학 글쓰기(SWH)를 적용한 고등학교 과제연구의 효과)

  • Moon, Saetbyeol;Choi, Wonho
    • Journal of the Korean Chemical Society
    • /
    • v.62 no.5
    • /
    • pp.398-411
    • /
    • 2018
  • The purpose of this study is to investigate the effects of research project activities using the science writing heuristic on science inquiry abilities and attitudes toward science in high school students. For this purpose, we conducted the research project activities using the science writing heuristic consisting of questioning, experimental design, observation, argument and evidence, reading, and reflection steps for 73 students of the second year of science core course in high school in Jeonnam. In order to analyze the effects of the program, we surveyed the scientific inquiry ability and attitude toward science, investigated the perception of the research project class applying science writing heuristic, and conducted interviews when there was difficulty in interpreting the results. And the results of this study are as follows. First, among the science inquiry abilities, the score of Reasoning, Hypothesis setting, Finding variables, Operational definition, Experimental design, Graphing and data interpretation, Generalization was significantly improved statistically (p<.05), but the score of Expectation was not statistically significant (p>.05). Second, among the attitudes toward science, the score of 'Leisure interest in science', 'Enjoyment of science lessons', 'Career interest in science' was significantly improved statistically (p<.05). And the score of 'Attitude to scientific inquiry' decreased but it's not significant statistically. The high school research project applying science writing heuristic had a positive effect on scientific inquiry ability and scientific attitude but it could be burden to students because it is led by students in a form different from general science class for a long time. And so continuous study on research project that minimize these disadvantages and maximize their merits is needed.

Study for the Status and Effectiveness of Science Prior Learning (과학 선행학습의 실태와 그 효과에 대한 연구)

  • Jo, Chang Won;Koo, Min Joo;Park, Jong Keun
    • The Journal of the Convergence on Culture Technology
    • /
    • v.6 no.4
    • /
    • pp.483-492
    • /
    • 2020
  • Considering the fact that many students and parents spend a considerable amount of time and economic power on prior learning and that the environments of internet-based society change rapidly, it is worth examining the status and effectiveness of prior learning. In response, the study surveyed 186 first-year students of A high school in Changwon on the basic status of science prior learning. By the analysis results for the status, 39.8% of the students surveyed said they had experience in prior learning in science. Among the students experienced, 56 students who started science prior learning after the start of winter vacation in the third grade of middle school were analyzed the specific status of science prior learning and the impact of science prior learning on science achievements. The semi-subject form of pre-learning in science showed the highest response rate with 50.0 percent, and the motivation for pre-learning in science was the highest with 33.9 percent improvement in test scores. The confidence and learning intention were positive when conducting prior learning in a semi-subject form, and interest and value were positive when conducting prior learning in a self-directed form. As a result of the survey on the effect of science prior learning, 71.4% of the students who experienced science prior learning showed positive scientific achievement.

Preparation of High Spin Five-Coordinate Iron(II) Complexes of 1,4,8,11-Tetraazacyclotetradecane and High Spin Six-Coordinate Iron(II) Complexes of 1,5,8,12-Tetraazadodecane (1,4,8,11-테트라아자사이클로테트라데칸의 높은 스핀 다섯배위철(II) 착화합물과 1,5,8,12-테트라아자도데칸의 높은 스핀 여섯배위철(II) 착화합물의 합성)

  • Myunghyun Paik Suh
    • Journal of the Korean Chemical Society
    • /
    • v.24 no.2
    • /
    • pp.139-145
    • /
    • 1980
  • High spin iron(II) complexes of 1,4,8,11-tetraazacyclotetradecane (cyclam), a macrocyclic ligand, and 1,5,8,12-tetraazadodecane (3,2,3-tet), a noncyclic ligand, have been prepared. The reaction of low spin $[Fe(cyclam)(CH_3CN)_2](ClO_4)_2$ with chloride ion in methanol produces high-spin $[Fe(cyclam)Cl]ClO_4$. Although $[Fe(cyclam)(CH_3CN)_2](ClO_4)_2$ is low spin, $[Fe(3,2,3-tet)(CH_3CN)_2](ClO_4)_2$ isolated in the present study is high spin. This difference is explained in terms of the smaller constrictive effect exerted by the noncyclic ligand than the cyclic ligand. The isolation of $[Fe(cyclam)Cl]ClO_4$ provides evidences against the current view that the presence of either unsaturation or substituents on the macrocyclic ligands is necessary for the successful preparation of high spin five-coordinate iron (II) complexes. Reactions of $[Fe(cyclam)Cl]ClO_4\;and\;[Fe(3,2,3-tet)(CH_3CN)_2](ClO_4)_2$ with carbon monoxide yield low spin six-coordinate $[Fe(cyclam)Cl(CO)]ClO_4\;and\;[Fe(3.2,3-tet)(CH_3CN)(CO)](ClO_4)_2$, respectively.

  • PDF

A Study on the Hydrolysis of p-Nitrophenyl Carboxylates by Micellar Surfactants Catalysts Involving Histidyl Residue (히스티딜기등을 포함하는 미셀성 계면활성제를 촉매로 사용한 파라니트로페닐 에스테르의 가수분해반응에 관한 연구)

  • Won Fae Koo;Choon Pyo Hong
    • Journal of the Korean Chemical Society
    • /
    • v.33 no.1
    • /
    • pp.3-10
    • /
    • 1989
  • In order to obtain a clue in understanding enzymatic hydrolysis in which the His-Cys moieties of papain protease is involved, we prepared cationic peptide-sufactants bearing histidyl, cysteinyl, and both histydyl and cysteinyl residues. Their catalytic efficiency toward the hydrolysis of PNPL were investigated in comicellar phases formed with $N^{+}C_{2}CysC_{12}$, $N^{+}C_{2}HisC_{12}$, $N^{+}C_{2}HisCysC_{12}$ increased markedly in the same order compared with that of $N^{+}C_{2}AlaC_{12}$. The markedly increased catalytic effects are attributed to the imidazole groups of $N^{+}C_{2}HisC_{12}$ and the thiol groups of $N^{+}C_{2}CysC_{12}$, and the large catalytic efficiency of $N^{+}C_{2}HisCysC_{12}$, is considered due to the interaction of the imidazole and the thiol groups. In order to investigate catalytic activities, rate constants for the functional groups, km* and dissociation constants, pKa have been determined. The results showed that $k^{\ast}_m$ and pKa of the imidazole groups were $7.91{\times}10^{-4}S^{-1}$ and 6.49, and those of the thiol groups were $6.00{\times}10^{-4}S^{-1}$ and 10.50. The catalytic effects of comicellar systems on the hydrolysis of p-nitrophenyl esters has increased according to the increasing size of the alkyl carbon number. Therefore, the catalytic effects have been increasing by the interaction of micellar hydrophobic parts and substrates as well as action of the functional groups.

  • PDF

Application of Ferrate(VI) on the Decomplexation of Cu(II)-EDTA

  • Tiwari, Diwakar;Yang, Jae-Kyu;Chang, Yoon-Young;Lee, Seung-Mok
    • Environmental Engineering Research
    • /
    • v.13 no.3
    • /
    • pp.131-135
    • /
    • 2008
  • In this study, Fe(VI) was employed as a multi-functional agent to treat the simulated industrial wastewater contaminated with Cu(II)-EDTA through oxidation of EDTA, decomplexation of Cu(II)-EDTA and subsequent removal of free copper through precipitation. The decomplexation of $10^{-4}\;M$ Cu(II)-EDTA species was performed as a function of pH at excess concentration of Fe(VI). It was noted that the acidic conditions favor the decomplexation of Cu(II)-EDTA as the decomplxation was almost 100% up to pH 6.5, while it was only 35% at pH 9.9. The enhanced degradation of Cu(II)-EDTA with decreasing the pH could be explained by the different speciation of Fe(VI). $HFeO_4^-$ and $H_2FeO_4$, which are relatively more reactive than the unprotonated species $FeO_4^{2-}$, are predominant species below neutral pH. It was noted that the decomplexation reaction is extremely fast and within 5 to10 min of contact, 100% of Cu(II)-EDTA was decomplexed at pH 4.0. However, at higher pH (i.e., pH 10.0) the decomplexation process was relatively slow and it was observed that even after 180 min of contact, maximum ca 37% of Cu(II)-EDTA was decomplexed. In order to discuss the kinetics of the decomplexation of Cu(II)-EDTA, the data was slightly fitted better for the second order rate reaction than the first order rate reaction in the excess of Fe(VI) concentration. On the other hand, the removal efficiency of free Cu(II) ions was also obtained at pH 4.0 and 10.0. It was probably removed through adsorption/coagulation with the reduced iron i.e., Fe(III). The removal of total Cu(II) was rapid at pH 4.0 whereas, it was slow at pH 10.0. Although the decomplexation was 100% at lower pH, the removal of free Cu(II) was relatively slow. This result may be explicable due to the reason that at lower pH values the adsorption/coagulation capacity of Fe(III) is greatly retarded. On the other hand, at higher pH values the decomplexation of Cu(II)-EDTA was partial, hence, slower Cu(II) removal was occurred.

Analysis of Characteristics of Linkage between Science and Technology in U.S. Considering R&D Expenditure (연구개발비규모를 고려한 과학지식의 기술연계 특성 분석 : 미국 사례)

  • Shim, Woo-Jung
    • Journal of Korea Technology Innovation Society
    • /
    • v.15 no.1
    • /
    • pp.47-75
    • /
    • 2012
  • Basic research have contributed to technological growth or economic growth in U.S. Specially recent studies say that universities also contribute to economic development through scientific activities like science research, education, technology transfers. But we can not assure whether scientific knowledge was connected to real technology or economic performance, and it is difficult to figure out the effect of scientific output. "What is the exact performance of scientific knowledge?" It is still obscure. In this context, this paper analyzes characteristics of the linkage of science and technology. Data are U.S. R&D expenditure, scientific articles, citation of articles in U.S. patents by fields and sectors. As a result, university sector has the most weight of the linkage of science and technology. But, in relative connection rate analysis, industrial sector's is stronger than any other sectors. In the field analysis, linkage of science and technology is very strong in Chemistry, Physics, Biological sciences fields. And recently the linkage was increased in the fields of Computer science, Agricultural science, Engineering. Finally, this paper supports funding policy or estimation policy of government to product of scientific knowledge. University sector is still important because it has the most weight of the linkage. Scientific knowledge of industrial sector is also important. The connection rate of industrial science is the strongest in all sectors. And this research classify the R&D type by science fields. Considering the differences of science fields is needed to product science knowledge effectively.

  • PDF

Status of Employment-Related Qualifications Similar to a Medical Laboratory Technology Major (임상병리기술학 전공 유사 취업연계 자격 현황)

  • Sung, Hyun Ho;Kim, Dae Sik;Cho, Young Kuk;Yoon, Ki Nam
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.50 no.4
    • /
    • pp.525-534
    • /
    • 2018
  • This study evaluated the various qualifications that can be linked to employment similar to the medical laboratory technology major. The qualifications for employment outside the medical laboratory technology major are industrial health instructor, doping control officer, audiologist, sign language interpreter, health education specialist, claim adjuster, Korea life underwriter, administrative manager, hospital administrator, insurance review manager, and hospital coordinator. The qualifications for employment similar to the medical laboratory technology major include the clinical research coordinator, clinical research associate, anatomist, analytical chemistry analysts, hazardous materials industry engineers, biotechnologist, biosafety managers, biotechnology technicians, medical device quality officers, animal care nurse, industrial engineer hazardous material, bioprocess engineer, biosafety officer, certified technology consultant, director of medical device quality control, laboratory animal technician, animal nursing technician, and cruise medical manager. Therefore, it is necessary to conduct a social analysis survey of the various qualifications currently held by medical technologists. In addition, it will be necessary to investigate the current status of medical technologists working in other fields. In the future, medical technologists should expand the scope of their work through efforts to strengthen their individual work capacity, share cases, and strengthen their expertise.

Principle of restoration ecology reflected in the process creating the National Institute of Ecology

  • Kim, A. Reum;Lim, Bong Soon;Seol, Jaewon;Lee, Chang Seok
    • Journal of Ecology and Environment
    • /
    • v.45 no.3
    • /
    • pp.105-116
    • /
    • 2021
  • Background: The creation of the National Institute of Ecology began as a national alternative project to preserve mudflats instead of constructing the industrial complexes by reclamation, and achieve regional development. On the other hand, at the national level, the research institute for ecology was needed to cope with the worsening conditions for maintaining biodiversity due to accelerated climate change such as global warming and increased demand for development. In order to meet these needs, the National Institute of Ecology has the following objectives: (1) carries out studies for ecosystem change due to climate change and biodiversity conservation, (2) performs ecological education to the public through exhibition of various ecosystem models, and (3) promotes regional development through the ecological industry. Furthermore, to achieve these objectives, the National Institute of Ecology thoroughly followed the basic principles of ecology, especially restoration ecology, in the process of its construction. We introduce the principles and cases of ecological restoration applied in the process. Results: We minimized the impact on the ecosystem in order to harmonize with the surrounding environment in all the processes of construction. We pursued passive restoration following the principle of ecological restoration as a process of assisting the recovery of an ecosystem degraded for all the space except in land where artificial facilities were introduced. Reference information was applied thoroughly in the process of active restoration to create biome around the world, Korean peninsula forests, and wetland ecosystems. In order to realize true restoration, we pursued the ecological restoration in a landscape level as the follows. We moved the local road 6 and high-voltage power lines to underground to ensure ecological connectivity within the National Institute of Ecology campus. To enhance ecological diversity, we introduced perch poles and islands as well as floating leaved, emerged, wetland, and riparian plants in wetlands and mantle communities around the forests of the Korean Peninsula in the terrestrial ecosystem. Furthermore, in order to make the public aware of the importance of the intact nature, the low-lying landscape elements, which have disappeared due to excessive land use in most areas of Korea, was created by imitating demilitarized zone (DMZ) landscape that has these landscape elements. Conclusions: The National Institute of Ecology was created in an eco-friendly way by thoroughly reflecting the principles of ecology to suit its status and thus the impact on the existing ecosystem was minimized. This concept was also designed to be reflected in the process of operation. The results have become real, and a result of analysis on carbon budget analysis is approaching the carbon neutrality.

Integrated Science Teachers' Implementation and Changes to Apply the Curriculum-Instruction-Assessment (통합과학 교사의 교육과정-수업-평가 실행 및 변화 조사)

  • Park, HyunJu;Kim, NaHyeong
    • Journal of the Korean Chemical Society
    • /
    • v.64 no.6
    • /
    • pp.429-437
    • /
    • 2020
  • This study investigated a total of 529 integrated science teachers' implementation and changes to apply the curriculum-instruction-assessment. Data was collected through online survey on scientific competencies and skills, teaching-learning and assessment methods, changes of teacher's preparation, topics/materials, teaching-learning, and assessment to apply the curriculum-instruction-assessment as teaching integrated science. The results of the study were as follows: first, in the integrated science class, teachers implemented more on scientific communication and scientific inquiry among scientific core competencies, and analysis and interpretation of data collection and communication among scientific skills. Teachers often taught in lectures and used multiple choice items and short essay for evaluation. Teacher groups with less than 10 years of teaching experience appeared to be less active in teaching scientific core competencies and skills than those with more than 10 years. Second, Teachers have increased more time and efforts to search and to organize various materials in addition to textbooks, and try to integrated concepts in various fields to prepare learning topics and textbooks. Third, even though teachers made little change in implementing the process-oriented assessment, they used instructional strategies to increase student engagement in the integrated science class, restructured the instruction to provide immediate feedback after conducting the assessment. It is necessary to build a system that ensures fairness and credibility of evaluation while respecting the autonomy and professionalism of teachers.