• Journal of the Korean Chemical Society
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• v.68 no.5
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• pp.274-286
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• 2024

This study aimed to investigate whether pre-service science major students at a college of education possess the inquiry competencies necessary to conduct a general chemistry laboratory class. For this purpose, a survey of students' experiences in school science, an assessment of knowledge of laboratory equipment, an assessment of science inquiry processes, and an assessment of chemistry experiment design skills were conducted. The results indicated that science education major students had insufficient understanding of the names and uses of chemical experiment tools, and they did not adequately perform the investigation processes required for the intended experiments. Additionally, it was shown that science education major students had inadequate inquiry competencies needed to conduct general chemistry experiments at the university level, such as insufficient chemistry experiment design skills.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.459-472
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• 2019

The purpose of this study was to investigate the effect of science writing for different audiences on preservice chemistry teachers' chemistry concept understanding and modeling ability in general chemistry experiment activities using Argument-based Modeling (AbM) strategy. And we also examined preservice chemistry teachers' perceptions of modeling in different audience groups. The participants of the study were 18 university students in the first grade of preservice chemistry teachers taking a general chemistry experiment course. They completed eleven topics of general chemistry experiment using argument-based modeling strategy. The understanding of chemistry concept was compared with the effect size of pre- and post-chemistry concept test scores. To find out modeling ability, we analyzed level of model by each preservice chemistry teacher. Analytical framework for the modeling ability was composed of three elements, explanation, representation, and communication. The questionnaire was conducted to check up on preservice chemistry teacher's recognition of modeling. The result of analyzing the effect of modeling for different audience on the understanding of chemistry concept and modeling ability, the preservice chemistry teachers' were found to be more effective when the level of audience was low. There was no difference in the recognition of modeling between the groups for audience. However, we could confirm that the responses of preservice chemistry teachers are changed in concrete when they have an experience in succession on modeling.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.124-136
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• 2018

In this study, we applied the flipped-classroom to the general chemistry experiment lecture of the domestic university with strong teacher-led, and explored the effects and possibilities of the course. For this purpose, 30 students who were enrolled in the Science Education Department of the College of Education in the metropolitan area were randomly assigned to two groups, namely, the flipped-classroom group and the traditional class group. Then, we developed a general chemistry experiment lessons based on the flipped-classroom along with visual materials and we applied the lessons for 15 weeks. After all the classes, we conducted a survey to see the students' perception of the general chemistry experiment lecture by flipped classroom. As a result of analysis, the students of the flipped-classroom group were more positive than the students of the traditional class group in terms of the usefulness of the class activity, the importance of each activity element for the successful learning, the learning level, and the intention for another lesson. As a result of analyzing students' perceptions in terms of general chemical experiment activities such as conducting experiments or writing reports and understanding the contents of experiments, the average score of the flippedclassroom group was higher than the traditional class group, and the main cause of this result was the video material provided by prior learning activities. In addition, as a result of analyzing students' perceptions in terms of interactions and self-directed learning in class, the average score of the flipped-classroom group was generally higher than the traditional class group. In particular, students' interactions and self-directed learning were statistically significant differences between the two groups. And the students' perception of video material was very positive, and it was analyzed that the video that the instructor directly explained experiment theory and method was the most favorite videos of students. We discussed educational implications of these findings.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.716-730
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• 2017

In this paper, we propose a transliteration approach based on semantic information (i.e., language origin and gender) which are automatically learnt from the person name, aiming to transliterate the person name of Uyghur into Chinese. The proposed approach integrates semantic scores (i.e., performance on language origin and gender detection) with general transliteration model and generates the semantic knowledge-based model which can produce the best candidate transliteration results. In the experiment, we use the datasets which contain the person names of different language origins: Uyghur and Chinese. The results show that the proposed semantic transliteration model substantially outperforms the general transliteration model and greatly improves the mean reciprocal rank (MRR) performance on two datasets, as well as aids in developing more efficient transliteration for named entities.

• Journal of Veterinary Clinics
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• v.25 no.5
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• pp.363-369
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• 2008

The aim of this study was to establish an experiment animal model for easy diagnosis and monitoring effect of treatment of cholelithiasis by cholesterol and mixed gall stone. In 12 adult beagle dogs, five dogs there were in the control group and seven dogs in the experiment group with ligated cystic duct. General clinical signs were recorded, CBC and blood chemistry were examined. Control group and experiment group were evaluated every 2 weeks for a period of 20 weeks. The results were (1) Total blirubin, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST) activity were significantly higher in the experiment group with ligated cystic duct than control group during 2-8 weeks. (2) Total alkaline phosphatase (TALP) activity was significantly higher when compare with control group during 2-8 weeks. Bone alkaline phosphatase(BALP) activity was increased slightly between 2 and 8 weeks but was decreased between 10 and 20 weeks. (3) Blood urea nitrogen (BUN) was decreased between 2 and 8 weeks. After 10 weeks, this was in normal range. (4) On complate blood count (CBC), $Ca^{2+}$ and P were not changed until 20 weeks. (5) On clinical signs in experimental group, they observed a depression, yellow color of mucus membrane and conjunctiva, xanthinuria and xanthochromic. The present study showed that the experimental animal model with ligated cystic duct was a useful model to study biliary tract disease.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.283-291
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• 2003

The purpose of this research was to analyze and improve the experiment, observing the color change under compression on the equilibrium of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system, described in high school and general chemistry textbooks. Chemistry textbooks described that the reddish brown color got lighter on the compression of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system. This misinterpretation was due to no consideration of $NO_2$ concentration increase by the volume decrease. In order to propose a correct interpretation, the changes of color and temperature on compression were quantitatively measured and compared with theoretical studies. In addition, an improved experiment, excluding the effect of $NO_2$ concentration increase, was proposed to observe only the color change of the net equilibrium shift.

• Korean Journal of Environmental Agriculture
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• v.20 no.5
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• pp.330-334
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• 2001

The polymorphism of Azospirillum isolates from ornamental rhizosphere and two reference strains were examined with respect to intrinsic antibiotic resistance (IAR) profile. All the isolates showed different intrinsic resistances to different antibiotics viz., tetracycline, kanamycin, nalidixic acid, streptomycin, ampicillin, spectinomycin and chloramphenicol. All the strains demonstrated susceptibility to high concentration of all antibiotics used in the present experiment. In addition to these general patterns, we also obseved the multiple antibiotic resistances of Azospirillum strains. The Azospirillum sp. OAD-11 was resistant to tetracycline, streptomycin and ampicillin, and Azospirillum sp. OAD-57 was resistant to tetracycline and streptomycin. Conversely, Azospirillum sp. OAD-9 possessed the dual susceptibility to tetracycline and spectinomycin, whereas Azospirillum sp. OAD-37 was dual susceptible to streptomycin and kanamycin. Such multiple antibiotic resistant/susceptible traits could be useful for the identification of the strains in field experiments or in molecular genetic transfer experiments.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3771-3776
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• 2010

The dynamics of the $CN^-$-ligated ferric cytochrome c (CytcCN) in $D_2O$ at 283 K following Q-band photoexcitation at 575 nm was observed using femtosecond time-resolved vibrational spectroscopy. The equilibrium vibrational spectrum of the CN stretching mode of CytcCN shows two overlapping bands: one main band (82%) at $2122\;cm^{-1}$ with $23\;cm^{-1}$ full width at half maximum (fwhm) and the other band (18%) at $2116\;cm^{-1}$ with $7\;cm^{-1}$ fwhm. The time-resolved spectra show bleaching of the CN fundamental mode of CytcCN and two absorption features at lower energies. The bleach signal and both absorption features are all formed within the time resolution of the experiment (< 200 fs) and decay with a life time of 1.9 ps. One transient absorption feature, appearing immediately red to the bleach signal, results from the thermal excitation of low-frequency modes of the heme that anharmonically couple to the CN fundamental mode, thereby shifting the CN mode to lower energies. The shift of the CN mode decays with a lifetime of 2 ps, equivalent to the time scale for vibrational cooling of the low-frequency heme modes. The other transient absorption feature, which is 3.3 times weaker than the bleach signal and shifted $27\;cm^{-1}$ toward lower energies, is attributed to the CN mode in an electronically excited state where the CN bond is weakened with a lowered extinction coefficient. These observations suggest that photoexcited CytcCN mainly undergoes ultrafast radiationless relaxation, causing photo-deligation of $CN^-$ from CytcCN highly inefficient. As also observed in $CN^-$-ligated myoglobin, inefficient ligand photodissociation might be a general property of $CN^-$-ligated ferric hemes.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.302-310
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• 2012

Bio assay of mercury and cadmium ions were searched using voltammetric analysis using DNA doped carbon nanotube paste electrodes (DCP). The square-wave stripping voltammetryic optimized results indicated working ranges of 1-10.0 $ngL^{-1}$ and 20-100 $ugL^{-1}$, Hg(II) Cd(II) within an accumulation time of 120 seconds, in 0.1-M phosphate buffer solutions of pH 6.3. The relative standard deviations of 5 $ngL^{-1}$ Hg(II) and Cd(II) that observed were 0.14 and 0.22% (n=12), respectively, using optimum conditions. The low detection limit (S/N) was pegged at 0.1 $ngL^{-1}$ ($4.9{\times}10^{-11}M$) Hg(II) and 0.2 $ngL^{-1}$ ($1.77{\times}10^{-10}M$) Cd(II). The developed methods can be applied to assays in biological fish kidneys and water samples.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.310-316
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• 2006

In this study, activated carbon in a powder form was used to remove dissolved ammonia which causes a fouling smell in water. Since the adsorption capacity of common powder activated carbon is not high enough, we prepared powder activated carbon deposited on an acid solution to enhance the adsorption capacity. The acid-impregnated activated carbon was applied on the surface of porous fibril support ($10{\sim}50{\mu}m$) by which adsorption and separation processes take place simultaneously by varying effective pressure. As the result, the ammonia removal efficiency is above 60% in the mixing process which is 10~15% higher than general powder activated carbon. From the result of an experiment on the pure permeable test of a dynamic membrane, its transmittance is 400~700 LMH (liter per hour), indicating that the prepared membrane works as a microfiltration membrane. Therefore, it is expected that the membrane prepared in this way would improve the efficiency of water treatment than conventional membranes.