• The Journal of the Korean dental association
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• v.58 no.7
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• pp.413-434
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• 2020

Recently, there are much improvement in optical and mechanical properties of dental ceramic materials coupled with improved fabrication techniques, which have caused a considerable shift in the preference of the dentists to ceramic restorations. Because the chemical composition and microstructure of all-ceramic materials are different by the type, correct choice of cement type and surface treatment procedure, and cementation strategy is essential for the success of ceramic restorations with adequate retention and decreased incidence of complications. This manuscript reviews on the most often prescribed and some newly developed ceramic materials, and the selection criteria and usage guidelines of cement materials that are used in conjunction with various ceramic materials. This manuscript emphasizes that continuous updating the information of newly developed ceramic and cement materials and application techniques by the dentists and dental staffs are demanding in response to the constantly improving ceramic and cement materials and corresponding application protocol changes.

• Corrosion Science and Technology
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• v.16 no.1
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• pp.48-48
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• 2017

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.54.2-54
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• 1998

• Archives of Metallurgy and Materials
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• v.67 no.4
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• pp.1469-1473
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• 2022

Tungsten diselenide (WSe₂) is one of the promising transition metal dichalcogenides (TMDs) for nanoelectronics and optoelectronics. To enhance and tune the electronic performance of TMDs, chemical functionalization via covalent and van der Waals approaches has been suggested. In the present report, the electric and structural transition of WSe₂ oxidized by exposure to O₃ is investigated using scanning tunneling microscopy. It is demonstrated that the exposure of WSe₂/high-ordered pyrolytic graphite sample to O₃ induces the formation of molecular adsorbates on the surface, which enables to increase in the density of states near the valence band edge, resulting from electric structural modification of domain boundaries via exposure of atomic O. According to the work function extracted by Kelvin probe force microscopy, monolayer WSe₂ with the O₃ exposure results in a gradual increase in work function as the exposure to O₃. Therefore, the present report demonstrates the potential pathway for the chemical functionalization of TMDs to enhance the electric performance of TMDs devices.

• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.313-320
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• 2009

It takes elementary school teachers long time to search for instructional materials. They have also difficulties with choosing proper contents among much of the overlapping materials. Thus this study set out to investigate the current utilization of web materials by teachers, analyze the materials in the existing homepage, and identify useful materials for teachers. For those purposes, the investigator developed an evaluation framework to analyze science education materials in the existing homepage and analyzed materials using the framework. The materials had developed in the past failed to reflect the demands of teachers, who were the users, actively. Therefore, we took a survey to analyze their demands and reflected the results to establish a set of criteria to analyze materials. After dividing materials according to utilization and format, the external and internal elements of materials were assessed according to the evaluation items. If they systematically select many teaching and learning materials developed for elementary science and make efforts to vitalize their educational usage by sorting out overlapping materials and developing new needed ones, they will be able to save a huge amount of expenses and maximize the efficiency as educational materials.

• Carbon letters
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• v.28
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• pp.1-8
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• 2018

Graphene is a single atomic layer of carbon atoms, and has exceptional electrical, mechanical, and optical characteristics. It has been broadly utilized in the fields of material science, physics, chemistry, device fabrication, information, and biology. In this review paper, we briefly investigate the ideas, structure, characteristics, and fabrication techniques for graphene applications in lithium ion batteries (LIBs). In LIBs, a constant three-dimensional (3D) conductive system can adequately enhance the transportation of electrons and ions of the electrode material. The use of 3D graphene and graphene-expansion electrode materials can significantly upgrade LIBs characteristics to give higher electric conductivity, greater capacity, and good stability. This review demonstrates several recent advances in graphene-containing LIB electrode materials, and addresses probable trends into the future.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.47-53
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• 2010

Ceramics with perovskite-type structure are interesting functional materials for several energy conversion processes due to their flexible structure and a variety of properties. Prominent examples are electrode materials in fuel cells and batteries, thermoelectric converters, piezoelectrics, and photocatalysts. The very attractive physical-chemical properties of perovskite-type phases can be modified in a controlled way by changing the composition and crystallographic structure in tailor-made soft chemistry synthesis processes. Improved thermoelectric materials such as cobaltates with p-type conductivity and n-type manganates are developed by following theoretical predictions and tested to be applied in oxidic thermoelectric converters.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.463-466
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• 2011

Wet foams formed through direct foaming were stabilized using various concentrations of amiphiphilic particles that could control pore size and porosity. These porous materials showed moderate strength upon compression with high porosity. Bubble size and wet foam stability were tailored by amphiphile concentration, particle concentration, contact angle, and pH of the suspension to obtain crack-free porous solid after sintering. Closed and open pores were obtained with sizes of 30~300 ${\mu}m$ and porosities of over 80%.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.97-97
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• 2009

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.65-65
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• 2002