• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.507-515
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• 1999

This study is to develope the performance scoring rubrics for the inquiry-based experiments of general chemistry course in the college of education. Two types of analytic scoring rubrics have been developed for nine different experiments. The first one is to assess scientific process skills from the written experimental reports. These analytic scoring rubrics include seven process skills selected from the Lawson's 'creative and critical thinking skills' and other known process skills. The second one is to assess the individual manipulative skills and experimental attitudes through direct observations by the teacher. The content validity of all scoring rubrics was testified by six science educators. Also the inter-scorer reliability of analytic scoring rubrics administered on the students' experimental reports was examined. The correlation coefficient between the scores obtained from the experiments and those of the written test for theoretical knowledges was found to be r=.663(p <.01). From the variance($r^2$=.440), we would say indirectly that the 56% of this experimental assessment does not overlap with the theoretical knowledges test and assesses students' science process skills, manipulative skills, and attitudes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.7 no.1
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• pp.7-13
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• 1978

Changes in contents of general components of comfrey cultured in Korea were experimented and amino acids were analyzed by thin layer chromatography (T.L.C.) and gas chromatography (G.L.C.). The results obtained were as follows; 1. General components of comfrey such as moisture, fat, protein, carbohydrate, crude fiber and total ash were 13.20, 2.22, 22.30, 37.62, 9.38 and 15.06%. respectively, after 60 days growth. 2. The root of comfrey after 60 days contained 6.03% of alanine, 2.24% valine, 10.77% arginine, 2.96% glycine, 4.08% histidine. 1.54% isoleucine, 0.58% cystein, 1.72% methionine, 7.55% aspartic acid, 7.81% glutamic acid and 4.65% lysine in the gas chromatographic analysis of amino acid composition 3. The crude protein was decreased after 60 days of growth whereas the contents of carbohydrate, crude fiber and total ash were increased. 4. The total amount of amino acids in root was greater than that in leaf of comfrey.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.334-337
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• 2020

Korea Laboratory Accreditation Scheme (KOLAS) introduces a new standard for test and calibration laboratories to operate management system and to produce valid results in accordance with the requirements of KS Q ISO/IEC 17025. The standard is based on the national standard law for the accreditation of test, inspection and calibration laboratories. International Laboratory Accreditation Cooperation (ILAC) has recently established its new criteria. The accredited test and calibration laboratories should complete the transition of their management system by November 2020 following KS Q ISO/IEC 17025:2017. A total of 899 of test, inspection and calibration laboratories in Korea are influenced by the transition policy. This paper summarized general requirements for a competence of laboratory management system.

• Journal of Engineering Education Research
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• v.22 no.4
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• pp.22-31
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• 2019

This study aims to elucidate the relationship between physics and mathematics to predict achievement for the college level of engineering courses. For the last 4 years, more than 3,000 engineering college freshmen of this study took the diagnostic tests on three subjects, which were physics, mathematics, and chemistry before enrollment. We studied how strongly these diagnostic scores can predict each general college course grades. The correlation between the physics diagnostic scores and the course grades in physics was .264, which was significantly lower than the correlation between the mathematics scores and the physics grades, .311. This stronger prediction of the mathematical diagnostic scores for the general course grades was not found when predicting the grades in chemistry. We therefore conclude that mathematical preparation can unexpectedly predict future achievement in physics better than physics preparation due to the academic interrelationships between mathematics and physics.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.2
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• pp.119-126
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• 2002

In this study, general engine oil and the Miracle top engine oil of Dongjin chemistry company were tested to find the effects to the SI engine performance. Roller dynamometer used to find maximum power, fuel consumption rate and the emission. Maximum power was measured higher when the Miracle top engine oil was used in the vehicle. By use of the Miracle top engine oil, fuel consumption rate and emission was measured lower and compression pressure was higher compared use of general engine oil. Also the Miracle top engine oil was found to decrease the engine noise at the low RPM. And after 1,500km drive at the same condition, the dust in the oil pan and oil filter was measured less when the Miracle top engine oil used compared than general engine oil used.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.197-200
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• 2013

The bound state wave functions for all the known exactly solvable potentials can be expressed in terms of orthogonal polynomials because the polynomials always satisfy the boundary conditions with a proper weight function. The orthogonality of polynomials is of great importance because the orthogonality characterizes the wave functions and consequently the quantum system. Though the orthogonality of orthogonal polynomials has been known for hundred years, the known orthogonality is found to be inadequate for polynomials appearing in some exactly solvable potentials, for example, Ginocchio potential. For those potentials a more general orthogonality is defined and algebraically derived. It is found that the general orthogonality is valid with a certain constraint and the constraint is very useful in understanding the system.

• Journal of Korean Elementary Science Education
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• v.38 no.1
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• pp.130-148
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• 2019

This study compared the characteristics of scientific poems written by scientifically-gifted and general elementary students, and their perceptions of writing scientific poem. To do this, 5~6 graders (n=100) at two gifted science education institutes and 5~6 graders (n=93) at a elementary school in Seoul were selected. Scientific poems written by the students were analyzed according to their numbers and types. Their perceptions of writing scientific poems were also analyzed through a questionnaire and group interviews. The analysis of the results revealed that the general students wrote more scientific poems than the scientifically-gifted students for thirty minutes. The general students mainly named the titles in a direct way, while scientifically-gifted students did it in an implicit way. The free verse poems in both general students and scientifically-gifted students appeared most frequently, and the prose or narrative poems also often appeared. The general and scientifically-gifted students frequently used impersonation, and some students did not use metaphors. They didn't connect the scientific knowledge for multiple grade. While the poems of the general students evenly included the scientific knowledge for various academic fields, those of scientifically-gifted students tended to include the scientific knowledge for physics or chemistry. The poems of scientifically-gifted students tended to include more science process skills, especially in basic inquiry skills, than those of general students. The scientifically-gifted students wrote scientific poems in a more expanded form regarding the scientific knowledge, than the general students. Scientifically-gifted students perceived the educational benefits of writing scientific poems more positively based on various cognitive and affective aspects. However, many scientifically-gifted and general students had also several difficulties in the processes of writing scientific poems. Educational implications of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.64 no.3
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• pp.175-188
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• 2020

The purpose of this study was to analyze chemistry textbooks and teachers' guidebooks from the perspective of 'Ignorance', one of the important features of model. This is because the emphasis is on developing modeling capabilities for students in the 2015 Revised Curriculum. For this, Arrhenius model and Brønsted-Lowry model were selected as acid and base models in neutralization reaction which are important contents in chemistry curriculum. The analysis criteria of this study were extracted by analyzing previous studies and four general chemistry textbooks dealing with 'Ignorance' related to acid and base neutralization reaction. Based on the analysis criteria, we analyzed nine chemistry I textbooks and teacher's guides and six chemistry II textbooks and teacher's guides of the 2015 revised curriculum. In addition, we analyzed contents of four chemistry I textbooks and teacher's guides and three chemistry II textbooks and teacher's guides in the 2009 revised curriculum for comparison according to revised curriculums. We analyzed the contents related to the concept of 'neutralization reaction', 'neutrality', 'quantitative relation of neutralization reaction', 'degree of ionization', and 'ionization constant'. Based on the results of this study, we proposed a way to present 'Ignorance' of the models in teachers' guidebooks that chemistry teachers can understand 'Ignorance' of model and teach modeling capabilities for students.

• YAKHAK HOEJI
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• v.50 no.3
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• pp.177-183
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• 2006

Women's aging made a functional decline at ovary, This functional problem causes estrogen deficiency and many disorders, such as, sexual dysfunction, obesity, osteoporosis, urinary incontinence, skin and all body's aging, etc. We determined the ameliorative effects of some herbal extracts mixture on postmenopausal symptoms in ovariectomized Sprague Dawley rats. Nine-weeks-old female rats were ovariectomized and treated with singled pomegranate extracts (0.40, 1.20 g/kg/day) and mixed pomegranate extracts (1.08, 3.24g/kg/day) for 8 weeks. Oral administration of pomegranate extracts for 8 weeks were increased serum estradiol level and improved the serum osteocalcin, ALP activity and bone specific ALP level. And pomegranate extracts were reduced body weight, adipose tissue. Uterus weight in treated group tended to improve. In addition, the concentrationl of triglyceride and total cholesterol were lower after 8 weeks. HDL-cholesterol levels improved with does-dependency in treated groups. Collagen level on skin and cartilage showed a slight increase at treatment for 8 weeks. $^{\infty}These$ results showed that both of singular extract treatments and extracts mixture treatments were effective on general postmenopausal symptoms at overiectomized rats, and especially, the mixture treatments were more effective than singular treatment. $^{\infty}In$ conclusion, these herbal extracts' mixture showed improvement effect in general factors related with postmenopausal disorders.

• Journal of the Korean Chemical Society
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• v.40 no.10
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• pp.663-669
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• 1996

The rate constants for the nucleophilic addition reactions of thioglycolic acid to vinylsulfilimine(VSI) derivatives(p-OCH3, H, p-Cl and p-Br) were determined by an ultraviolet spectrophotometric method, and rate equations which can be applied over a wide pH range were obtained. On the basis of rate equation, general base catalysis and substituent effect, a plausible addition reaction mechanism was proposed: Below pH 3.0, the reaction was proceeded via the addition of neutral molecule to carbon-carbon double bond after protonation at the nitrogen atom of the sulfilimine, and in the pH range of 3.0 to 9.0, the neutral molecule and its anion attacked to carbon-carbon double bond competitively. Above pH 9.0, sulfide anion added to the double bond (Michael type addition).