• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.809-817
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• 2010

The primary purpose of this study was to investigate high school students' conceptual understanding of density for solids and liquids in pure and mixed substances who had preceded formal school science instruction on density and related topics. A concept assessment on density was developed and administered by demonstrative experiments accompanied by a written assessment test method to 120 general high school students in a metropolitan city. The scientific conceptions and alternative conceptions from students' responses were identified and the percentages of them were calculated. Then, their alternative conceptions and implicit theories on density were analyzed. About half of the students couldn't differentiate weight-volume-density and regarded density as an innate property of matter. Furthermore, the greater the number of variables involved in an experimental condition of the question, the more complicated and undifferentiated students' density concepts were. Students employed more improper variables such as particle size, intermolecular distance, surface tension, polarity of the solvent, etc. in explaining counter-intuitive observations. The implications for school science instruction were discussed.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.471-487
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• 2013

This review paper was written to provide background information as well as future application for aquatic ecologists interested in using stable isotope. Stable isotope techniques has proved to be an extremely useful to elucidate a lot of environmental and ecological problems. Stable isotopes have been used as possible tracers to identify sources, to quantify relative inputs in a system. When utilized carefully, stable isotope tools provides apparent advantages for the scientists to find out the processes of material cycles in various environments and energy flows in natural ecosystems.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.263-270
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• 2018

The purpose of this study was to review the current domestic research trends for published Nursing Intervention Studies on Cancer Patients Receiving Chemotherapy with Stomatitis. As a result of searching for 'chemo chemotherapy', 'stomatitis' and 'oral cavity' Of 23 studies. 13(56.6%) studies used a most commonly study design were nonequivalent control group non-synchronized design. But randomized control group pre-post design was only 2(8.7%). The most commonly used tool for measuring stomatitis was Oral Assessment Guide, which was used in 11(47.9%) studies. 19(82.6%) studies used a single intervention such as gargling. 13(56.5%) studies had positive effects on stomatitis. Based on the results of this study, that can provide basic data for developmental direction of stomatitis related nursing research in cancer patients and this research can be applied to research in the same field.

• Journal of the Korean Chemical Society
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• v.62 no.3
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• pp.226-234
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• 2018

In this study, the models described in the textbooks related to floating and sinking phenomena in the chemical domain were evaluated based on the aspect of nature related to the generation of models. To achieve this, we were targeting statement of textbooks from 7th curriculum to 2009 revised curriculum. Analysis of textbooks was performed for science of elementary school (total 2 textbooks) and science of middle school (total 21 textbooks) which dealt with these phenomena. According to the textbooks analysis, characteristics of statement way were (1) No description of the model's prerequisites, (2) Statement based matter viewpoint, (3) Lack of pattern principle, (4) Inadequacy of the case covered. Although the education about the model for the students should be preceded by the education related to the process of model creation rather than the activity using the model, the education about the nature of the model is insufficient. In order to solve this problem, we propose the model statement in textbooks and the development of the model evaluation tool related to model creation.

• Journal of Hospice and Palliative Care
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• v.13 no.2
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• pp.89-97
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• 2010

Purpose: This study investigated the relationship between the needs for hospice care and quality of life in cancer patients. Methods: Data were collected from 127 cancer patients hospitalized at a university hospital in Chonbuk between October, 2006 to March, 2007. Two instruments were used: cancer patients' need for hospice care, developed by Kang and Kim and quality of life developed by Tae et al. Results: The mean scores were 3.11 out of 4 for hospice care needs, and 5.25 out of 10 for quality of life. The correlation between needs for hospice care and quality of life was moderate and negative (r=-0.395, P<0.01). Among the four groups of needs, physical need was the most strongly correlated with quality of lifer (r=-0.388, P<0.01). The need for hospice care was significantly different according to participants' religion (t=6.02, P<0.05), and duration of disease (F=3.45, P< 0.05). Quality of life was significantly different according to participants' monthly income (F=3.38, P<0.05). cancer stage (F=8.10, P<0.01) and chemotherapy (t=6.09, P=0.015). Conclusion: The results suggested that the cancer patients' hospice care needs should be answered in order to improve their quality of life. While doing so, participants' characteristic need should also be considered.

• Prospectives of Industrial Chemistry
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• v.22 no.6
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• pp.26-40
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• 2019

고령화 사회에 접어들면서 신경, 정신질환으로 인한 사회경제적 부담이 늘어나고 있다. 이를 해결하기 위해서는 관련된 신경 회로를 직접적으로 자극하거나 그곳에서 일어나는 일을 실시간으로 감지할 수 있는 장비의 개발이 필수적이다. 하지만 이를 위한 수많은 공학적 도구의 개발에도 불구하고, 뛰어난 공간적/시간적 분해능, 세포형의 선택성, 장시간 안정성을 보유한 신경 인터페이스의 개발은 아직까지도 연구가 필요한 분야이다. 특히 신경전달 원리를 모두 이용하고자 하는 다기능 인터페이스의 개발은 최근 많은 연구자들의 관심 주제이고, 유연성을 가지는 인터페이스 개발 또한 안정성뿐만 아니라 신경 신호의 수명을 좌우하는 중요한 요소이기에 그 중요성을 인정받고 있다. 이를 해결하기 위한 여러 가지 과학적 시도 중에서도, 열 인장 공정으로 제작되는 섬유 형태의 장비는 그 통합적 기능을 수행하는 한 가지 방법으로써 많은 관심을 받고 있다. 이 기술은 다양한 기하학적 구조, 기능적 요소 등을 통합하는데 매우 유리하며, 또한 기존 반도체 공정으로 다루기 어려운 유연성 물질로 마이크로 스케일의 인터페이스를 제작하는 데에 매우 효과적이다. 본 기고문에서는 먼저 현재까지 개발되고 있는 다기능 유연 신경 인터페이스의 연구동향을 소개하고, 특히 그 중에서도 최근에 주목받고 있는 광섬유 기반의 인터페이스 개발에 대해 이야기하고자 한다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.4
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• pp.313-320
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• 2017

A spectroelectrochemical method has been applied to investigate the electrochemical behaviors and identify the kinds of samarium ions dissolved in high temperature molten LiCl-KCl eutectic. An optically transparent electrode (OTE) fabricated with a tungsten gauze as a working electrode has been used to conduct cyclic voltammetry and potential step chronoabsorptometry. Based on the reversibility of the redox reaction of $Sm^{3+}/Sm^{2+}$, which was determined from the cyclic voltammograms, the formal potential and the diffusion coefficient were calculated to be -1.99 V vs. $Cl_2/Cl^-$ and $2.53{\times}10^{-6}cm^2{\cdot}s^{-1}$, respectively. From the chronoabsorptometry results at the applied potential of -1.5 V vs. Ag/AgCl (1wt%), the characteristic peaks of absorption for samarium ions were determined to be 408.08 nm for $Sm^{3+}$ and 545.62 nm for $Sm^{2+}$. Potential step chronoabsorptometry was conducted using the anodic and the cathodic peak potentials from the voltammograms. Absorbance analysis at 545.63 nm shows that the diffusion coefficient of $Sm^{3+}$ is $2.15{\times}10^{-6}cm^2{\cdot}s^{-1}$, which is comparable to the value determined by cyclic voltammetry at the same temperature.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.290-303
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• 2011

The purpose of this study was to introduce the practical model on the enhancement of the divergent and convergent thinking skills through inquiry instruction in science class. In this study, the creative thinking skill has been defined by divergent thinking skill as the narrow sense. In the science field, the problem solving thinking skill is just same as the inquiry thinking skill. Also, the problem solving thinking skill has been defined by convergent thinking skill as the critical thinking skill. This new instruction had been used for the college student in the class of general chemistry laboratory for the one semester. The first results had been founded that the students' divergent thinking skill had been increased significantly. Especially, the skills of recognition of problems, the skills of making hypothesis, and the skills of transformation and interpretation of data had been increased significantly. The second results had been founded that the students' convergent thinking skill had been increased significantly. Especially, the skills of making hypothesis, the skills of transformation and interpretation of data, and the skills of making conclusion and generalization had been increased significantly. The third results had been founded that the students' the creative and problem solving thinking skill had been increased significantly. Especially, the rest of all skills exception the skill of control variables had been increased significantly.

• Journal of the Korean Chemical Society
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• v.66 no.4
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• pp.305-322
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• 2022

In this study, a practice-based teacher education program was developed and applied to improve the TPACK of pre-service chemistry teachers. Also the program effect and obstacles were confirmed by measuring the development of TPACK. The participants of this study were 20 pre-service chemistry teachers of 3rd grade and 2 pre-service chemistry teachers of 4th grade who took chemistry education courses at K University located in Chungcheongbuk Province. The developed teacher education program consisted of four stages: preparation, rehearsal, practice, and reflection. The feedbacks from researchers and colleagues pre-service teachers were provided in preparation, rehearsal, and reflection stages. As a result of the study, the program of this study did not show an educational effect in the "constructive learning activities" of preservice teachers, but it was found to have an educational effect in "problem solving". In other words, in "constructive learning activity", most pre-service teachers were at 0 level before and after the program. The pre-service teachers designed the class to unilaterally provide technology to simply use it as a tool to explain subject content or revise misconceptions, and learners can passively acquire knowledge. However, in the case of "problem solving", the pre-service teachers who were at level 0 before the educational program changed to level 1. Before the program, the pre-service teachers designed classes to solve problems by memory without using technology, but after the program they planned classes that provides opportunities to approach and solve various problems through the technology presented by the teacher. However, there were not many pre-service teachers corresponding to level 2, which constitutes voluntary learning in which learners use technology to solve various problems while selecting and variously manipulating technology. In addition, as obstacles to the TPACK development of pre-service chemistry teachers, there were external factors such as lack of classroom support environment for TPACK implementation, lack of time for education planning, and inadequate technology competency. And there were internal factors such as perspectives of traditional education and negative attitude toward technology. In particular, the proportion of pre-service teachers who preceived inappropriate technical competency as an external obstacles of TPACK development was high. Therefore, it was necessary to develop an education program corresponding to type 2 or type 3 that enables TPACK development through TK for pre-service teachers.

• Journal of the Korean Geographical Society
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• v.39 no.5 s.104
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• pp.722-734
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• 2004

Longitudinal profiles of bedrock rivers play a fundamental role in landscape history by setting the boundary conditions for landform evolution. Longitudinal profiles are changed with climatic conditions, lithology and tectonic movements. Tectonic movement is an important factor controlling longitudinal profiles, especially in tectonically active area where uplift rates are regarded as a major factor controlling channel gradient. However study on bedrock channel has made little progress, because controls over bedrock river incision are yet to be clarified. Previous numerical simulations have used a simple diffusion model, which links together the overall processes of bedrock channel erosion as in other landform evolution models. In this study, previous bedrock incision models based on physical processes (especially abrasion) are reviewed and new modifications are introduced. Using newly formulated numerical model, the role of spatial pattern and intensity of tectonic uplift on changes in river longitudinal profile was simulated and discussed.