• Title/Summary/Keyword: Chemistry

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A Study on Efficiency of Essential Oil for Dandruff Symptoms Relief - Focused on Tea tree oil - (비듬 증상 완화를 위한 에션셜 오일의 유효성 연구 - 티트리 오일을 중심으로 -)

  • Park, Eun-Ha
    • Journal of the Korean Society of Fashion and Beauty
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    • v.3 no.3 s.3
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    • pp.31-40
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    • 2005
  • The reason that aromatherapy began to draw attention again as the alternative therapy is because the essential oils that are used for aromatherapy not only allow the human body to maintain homeostasis but also have an effect on curing a mental feeling of fatigue and because these efficacies and effects are proceeding with being proved scientifically. Also, with coming to be high in a voice of concern about severally side effects that the modern medicine and the synthetic chemistry have, the aromatherapy came to be paid attention as the replacement therapy that can substitute for and supplement this. In particular, at the time of requiring a study on a substance to substitute for this after having been announced in Japan for 1998 a risk of Zincpyrithione that is being used as a component of dandruff treatment, it is thought that the aroma oil that was known for having an anti-dandruff effect has a merit of being easy in a user's access, thus it will be effective in curing the symptom of dandruff. Accordingly, this study conducted the following experiment in a bid to examine whether the aroma oil has the anti-microbial effect on the actual malassezia. First of all, it measured the minimum concentration of aroma oil in which the growth of malassezia is inhibited, by carrying out MIC(Minimum Inhibition Concentration) test in terms of anti-microbial activity against Malassezia furfur KCTC 7744 while using oils of Patchouli, Rosemary, Lavender, and Tea tree among aroma oils that are being used for dandruff treatment. As a result of that, Tea tree oil has the most excellent anti-microbial activity, and the measurement result of anti-microbial activity was shown in order of Lavender oil>Rosemary oil>Patchouli oil. Next, it carried out the is actually eased by applying Tea tree oil directly to the scalp of dandruff. In consequence of the experiment, the massage of Tea tree oil indicated the result of relieving the symptoms of dandruff such as scale, itch, pain, inflammation, and sebum, and among these symptoms of dandruff, it was shown to be most effective in easing itch. Especially, this clinical experiment was indicated that the massage of Tea tree oil has the most effect on relieving itch of targets with a dry-skin type who had no experience of dandruff treatment.

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International Comparison of Junior High School Science Textbooks (중학교 과학 교과서의 국제 비교)

  • Park, Yune-Bae
    • Journal of The Korean Association For Science Education
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    • v.18 no.1
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    • pp.19-34
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    • 1998
  • This study compared junior high school science textbooks(for grade $7{\sim}9$) of the USA, Australia, Japan, and Korea. Specifically, the amount and pattern of knowledge, process skills, activities, contexts, nature of science, and integration topics were compared in terms of country, grade, and content. The results of analysis are as follow: 1) Physics, chemistry, biology, and earth science were equally distributed in textbooks of Korea and Japan. In Korean textbooks, "law" was more emphasized compared with other countries' textbooks. 2) The most popular process skills were proportion and controlling variables in Korea's textbooks. Correlation, cause/effect, and proportion in Japan's textbooks. Controlling variables and data transformation in textbooks of USA and Australia. 3) Experiment and observation were the most popular activities in textbooks of Korea, Japan, and Australia. In textbooks of the USA, observation, experiment, survey, practice, and measurement activities were used evenly. 4) In textbooks of Korea and Japan, pure science and natural environment contexts were the most popular. 5) There was no chapter dealing with nature of science in textbooks of Korea and Japan. 6) Integration topics between science and technology were the most popular. Based on these findings, several implications on Korean science textbooks were discussed.

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The Effect of Grouping Method in Cooperative Learning Strategy Applied to Concept Learning (개념 학습에 적용한 협동학습 전략에서 소집단 구성 방법의 효과)

  • Noh, Tae-Hee;Cha, Jeong-Ho;Jeon, Kyung-Moon;Jeong, Tae-Ho;Han, Jae-Young;Choi, Yong-Nam
    • Journal of The Korean Association For Science Education
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    • v.19 no.3
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    • pp.400-408
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    • 1999
  • This study investigated the effect of the grouping method in cooperative learning applied to chemistry concept learning. Two grouping methods used were the HML (High-Medium-Low) and the HL/MM (High-Low/Medium-Medium) ability grouping. Three classes (N = 136) at a high school in Seoul were randomly assigned to the control and the treatment groups. Before instruction. the test of attitude toward science instruction, the perception questionnaire of learning environment consisting of three subtests (participation, conflict, and competition), and the questionnaire of self-esteem were administered, and a mid-term examination score was obtained. These scores were used as covariates. After instruction, the three tests administered before instruction and the conceptions test were administered. Two-way ANCOVA results revealed that there was a significant interaction between the treatment and the level of previous achievement. The low-level students in the HL/MM cooperative group performed better than those in the other groups. The cooperative groups, regardless of the grouping methods, exhibited more positive perception than the control group at participation subtest of the perception questionnaire of learning environment.

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Analyses of Volition Strategy by Achievement Level of the Students with High Learning Motivation (학습동기가 높은 학생들의 학업성취도 수준에 따른 의지조정 전략 분석)

  • Ko, You-Kyong;Kim, Hyun-Kyung;Choi, Byung-Soon
    • Journal of The Korean Association For Science Education
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    • v.26 no.3
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    • pp.376-384
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    • 2006
  • The purposes of this study were to analyze the frequency and type of volition strategy, according to achievement level, employed by students with high learning motivation, and to identify the role volition strategy plays in keeping students motived to learn science. To accomplish these aims, two groups of students(each containing three members) were selected. Students in the two groups both had the same cognitive level and high learning motivation. However, one group's science achievement was high, and the other was low. Through interviews and class observations, volition strategies students in the two groups used when they encountered hindrances in science learning were compared. Results of the study revealed a relationship between achievement level and volition strategy. Students showed differences in the frequency and types of volition strategies used according to science achievement. It was found that students with higher achievement levels used volition strategies more often to overcome hindrances in science learning than those with lower achievement levels. Furthermore, students with higher achievement levels generally used internal mind control strategies while those with lower achievement levels used environmental control strategies. Lastly, findings found that the types of volition strategies used by lower achievement level students were very limited.

Educational Implications of Pre-Service Science Teachers' Education by Analysis of Connection between Learning Contents Presented in the High School 'Science' and in the Pre-Service Science Textbooks of College of Education (고등학교 융합형 과학의 학습내용과 사범대학 예비과학교사 교육내용과의 연관성 분석을 통한 예비과학교사교육에 대한 시사점 고찰)

  • Kim, Nam-Hui;Shim, Kew-Cheol
    • Journal of The Korean Association For Science Education
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    • v.35 no.3
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    • pp.363-374
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    • 2015
  • The purpose of this study is to investigate the learning contents presented in high school science and in pre-service science textbooks of college of education, and to examine educational implications for pre-service science teachers by analysing their connection to each other. High school science is called as 'convergence science.' Seven high school science textbooks and eleven science textbooks related to physics, chemistry, biological science, and earth science for pre-service teachers were selected to analyse learning contents. The relationship between high school science with those of college-level science textbooks for pre-service science teachers was found when the learning contents were compared. Science textbooks for pre-service science teachers have the biggest number of learning contents on the chapter 'Energy and Environment' of high school science. About 86.6% of learning contents of high school science were introduced on textbooks on science, but pre-service teachers should learn the remainder. The part of learning contents presented in high school science textbooks was higher than the college-level for pre-service science teachers. Moreover, the part of learning contents was included in Engineering & Technology. And these required a special teacher education. Accordingly, the results suggested that learning contents for high school science should be optimized and reduced. Also, various educational programs should be developed and educational curriculum for pre-service science teachers should be revised.

The Effects of Dynamic Visual by Students' Field Independence-Dependence on Learning with Multiple Representations: Focused on Connecting Errors and Conceptual Understanding (다중표상학습에서 학생들의 장독립성.장의존성에 따른 동화상의 효과: 연계 오류와 개념 이해를 중심으로)

  • Noh, Tae-Hee;Moon, Se-Jeong;Lee, Jong-Hyun;Seo, Hyun-Ju;Kang, Hun-Sik
    • Journal of The Korean Association For Science Education
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    • v.29 no.2
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    • pp.156-167
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    • 2009
  • This study investigated the effects of dynamic visual on students' field independence-dependence on connecting errors and conceptual understanding in learning chemistry concepts with multiple representations. Seventh graders (N=123) at a co-ed middle school were assigned to a static visual (SV) group learning with text and static visual, and a dynamic visual (DV) group learning with text and dynamic visual. The students then learned 'Boyle's Law' and 'Charles's Law' for two class periods. Results revealed that the percentages of the DV group were lower than those of the SV group on connecting errors. However, the percentages of the students' connecting errors were still high regardless of their field independence-dependence. There was a little different tendency in the percentages of connecting errors between the two groups by students' field independence-dependence according to the types of connecting errors. The scores of the DV group were significantly higher than those of the SV group in a test on conceptual understanding. However, there was no significant interaction between the instruction and the students' field independence-dependence. Educational implications of these findings are discussed.

The Effect of Interview with Scientist and Engineer on the Science Career Orientation and Image of Scientists (과학기술자와의 인터뷰가 과학 진로 지향 및 과학자 이미지에 미치는 영향)

  • Jeon, Hwa-Young;Lee, Jin-Myung;Hong, Hun-Gi
    • Journal of The Korean Association For Science Education
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    • v.28 no.4
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    • pp.350-358
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    • 2008
  • The purpose of this study was to investigate the effects of interview with a scientist and engineer on service performance assessment on science career orientation and image of scientists. Science track students in the 11th grade carried out the interviews and made powerpoint presentations. After the students' presentation in the chemistry class, the teacher made comments on the contents of the interviews. Students gave presentation in each class for a year. Before starting this assessment, students took science career orientation questionnaire and DAST (draw-a-scientist-test). These two tests were conducted again at the end of the year. The results of this study showed that there was no significant difference between pre- and post-test score for the science career orientation. However, a significant difference was observed in the 'preference for science learning' category. These results showed that the career decision of a high school student has already been fixed rigidly. On the other hand, there was a significant difference (p < 0.01) between pre- and post-test on the image of scientists. This demonstrated that the stereotypic image for a scientist was reduced by the interview performance assessment and that, students came to have an affirmative perception of scientists on service.

THE PATIENTS' SATISFACTION FOLLOWING IMPLANT TREATMENT

  • Heo, Yoon-Young;Heo, Seong-Joo;Chang, Myung-Woo;Park, Ji-Man
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.6
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    • pp.569-576
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    • 2008
  • STATEMENT OF PROBLEM: While patient-centered outcomes are usually not reported, these may represent major aspects of the implant success for the patient. Use of a well-designed patient survey form can be an invaluable asset to the implant practitioners. PURPOSE: The objective of this study was to investigate patient satisfaction after implant therapy by means of a questionnaire. MATERIAL AND METHODS: South Korean patients (n = 100), who visited the dental examination center of Soon Chun Hyang university hospital, were asked to fill out the satisfaction questionnaire regarding aspects of cost, comfort, esthetics, chewing, gingival health, food impaction, phonetic aspect, screw loosening, and general satisfaction. Responses to statements were given on the Likert response scale. Four experimental groups of patients were distinguished with various location ($A_1,\;A_2,\;A_3$), year ($B_1,\;B_2,\;B_3$), number of implant replacements ($C_1,\;C_2,\;C_3$), and treatment cost ($D_1,\;D_2,\;D_3$). The reliability of the response scales was measured by calculation of its internal consistency, expressed as Cronbach's ${\alpha}$. The scales were distinguished by means of factor analysis method. Possible differences in scale scores among the groups were assessed by One-way ANOVA (${\alpha}$= 0.05). RESULTS: Patients responded to most of the statements with high satisfaction. But the mean scale score of statement about cost was low. After the verification of internal consistency and factor analysis, five components, e.g. general satisfaction, comfort, chewing efficiency, esthetics, and phonetic aspect were grouped together. These components could be explained with common meaning and the first factor was named as 'general satisfaction'. Differences in patient satisfaction on the scale with esthetics were present between patients who have been wearing the implant prosthesis less than three years and those more than seven years ($B_1<B_3$). CONCLUSION: The patients were generally satisfied with the outcome of implant treatment. But the patients' major complaint was high cost and while the statistically significant difference was not shown, the satisfaction scale about food impaction and esthetics was low. So the continuing efforts to make improvements about these problems are needed for the implant practitioners.

The Electrochemical Property Studies on Polyacenic Semiconductor Anode Material (음극 폴리아센 반도체 재료의 전기화학적 특성연구)

  • Kim Han-Joo;Park Jong-Eun;Son Won-Keun;Lee Hong-Ki;Park Soo-Gil;Lee Ju-Seong
    • Journal of the Korean Electrochemical Society
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    • v.2 no.3
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    • pp.134-137
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    • 1999
  • The polyacenic semiconductor material (PAS) electrode prepared by the pyrolytic treatment of phenol-formaldehyde resin is one of useful electrodes. As an anode material of lithium rechargeable batteries, amorphous carbon materials have been studied extensively because of their high electrochemcal performance and cyclicability. Carbon materials do not lead to the formation of lithium dendrite which is one of the most serious problems in applying Li-based materials to an electrode of batteries. The polyacene materials prepared from phenol resin at relatively low temperatures $(550\~750^{\circ}C)$ show a highly Li\doped state up to $C_2Li$ state without liberation of Li cluster. We prepared each polyacene materials at various temperature and investigated electro- chemical properties. We tried to change the mole ratio of [H]/[C] which is $0.24\~0.4$ range. Considering of electrochemical properties of PAS material, the PAS material is one of the most suitable materials for electrodes of a polymer battery.

Role of Sulfone Additive in Improving 4.6V High-Voltage Cycling Performance of Layered Oxide Battery Cathode (층상계 산화물 양극의 4.6V 고전압 특성 향상에서의 Sulfone 첨가제의 역할)

  • Kang, Joonsup;Nam, Kyung-Mo;Hwang, Eui-Hyeong;Kwon, Young-Gil;Song, Seung-Wan
    • Journal of the Korean Electrochemical Society
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    • v.19 no.1
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    • pp.1-8
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    • 2016
  • Capacity of layered lithium nickel-cobalt-manganese oxide ($LiNi_{1-x-y}Co_xMn_yO_2$) cathode material can increase by raising the charge cut-off voltage above 4.3 V vs. $Li/Li^+$, but it is limited due to anodic instability of conventional electrolyte. We have been screening and evaluating various sulfone-based compounds of dimethyl sulfone (DMS), diethyl sulfone (DES), ethyl methyl sulfone (EMS) as electrolyte additives for high-voltage applications. Here we report improved cycling performance of $LiNi_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode by the use of dimethyl sulfone (DMS) additive under an aggressive charge condition of 4.6 V, compared to that in conventional electrolyte, and cathode-electrolyte interfacial reaction behavior. The cathode with DMS delivered discharge capacities of $198-173mAhg^{-1}$ over 50 cycles and capacity retention of 84%. Surface analysis results indicate that DMS induces to form a surface protective film at the cathode and inhibit metal-dissolution, which is correlated to improved high-voltage cycling performance.