• Nano
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• v.13 no.12
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• pp.1850138.1-1850138.6
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• 2018

Two-dimensional (2D) or layered materials have a great potential for applications in energy storage, catalysis, optoelectronics and gas separation. Fabricating novel 2D or quasi-2D layered materials composed of relatively abundant and inexpensive atomic species is an important issue for practical usage in industry. Here, we suggest the layer-structured AlOOH (Boehmite) as a promising candidate for such applications. Boehmite is a well-known layer-structured material and a single-layer can be exfoliated from the bulk boehmite by breaking the interlayer hydrogen bonding. We study atomic and electronic band structures of both bulk and single-layer boehmite, and also obtain the single-layer exfoliation energy using first-principles calculations.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.42-45
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• 2009

We report simple structure red phosphorescent devices comprising only single organic layer structure. Maximum current efficiency of 9.44 cd/A and the driving voltage of 5.4 V are obtained in this single layer structure PHOLEDs, respectively. The mixed host system using electron transporting and hole transporting materials doped with $Ir(piq)_3$ provides such high efficiency and reasonable driving voltage. The principal to simplification is the direct charges injection from the metallic electrodes into mixed host materials.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.97-97
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• 2017

This study investigated the corrosion protection by electrodeposited copper layer on AZ31 Mg alloy with and without additional silver layer by immersion test, salt spray test, OCP transient and potentiodynamic polarization experiment. The single electrodeposited Cu layer on AZ31 Mg alloy showed a nodular structure with many imperfections of crevices between the nodules, which resulted in the fast initiation of pitting corrosion within first few hours of immersion. Double-layer coating of Cu and outer Ag layer slightly increased the initiation time for pitting corrosion. Triple-layer coatings of Cu/Ag/Cu exhibited the most efficient corrosion protection of AZ31 Mg alloy, compared to the single- and double-layer coatings. Surface morphology of the outer Cu layer in the triple-layer was changed from the nodular structure to fine particle structure with no crevices due to the presence of an additional Ag layer. Thus, the improved corrosion resistance of AZ31 Mg alloy by electrodeposited Cu/Ag or Cu/Ag/Cu layers is readily ascribed to the decreased number of imperfections in the electrodeposited layers due to the additional silver layer. It is concluded that the additional silver layer provides many nucleation sites for the second Cu plating, resulting in the formation of finer and denser structure than the first Cu electrodeposit.

• Journal of Sensor Science and Technology
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• v.27 no.3
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• pp.156-159
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• 2018

We developed a glucose sensor using glucose dehydrogenase flavin adenine dinucleotide (GDH-FAD). The structure of the three-layer glucose sensor was simplified, in which a single-layer design was used to lower the unit cost, and GDH-FAD was used to increase the measurement reliability. GDH-FAD has less impact on the 20 interfering substances that affect blood glucose measurement, such as galactose and maltose compared to glucose oxidase (GOD), and is not affected by the oxygen saturation; therefore, it is possible to measure both arterial or venous blood and thus less susceptibility to hematocrit. In this study, we developed a single-layer glucose sensor strip with low hematocrit effect using the GDH-FAD enzyme, and measured and evaluated the performance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.251-257
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• 1998

Spherical space frame structure with triangular network pattern, which has the various characteristics for the mechanic property, a funtional property, an aesthetic property and so on, has often been used as one of the most efficient space structures. It is expected that this type will be used widely in large-span structural roofs. But because this structure is made of network by combination of line elements there me many nodes therefore, the structure behavior is very complicated and there can be an overall collapse of structure by buckling phenomenon if the external force reaches a limitation. This kind of buckling is due to geometric shape, network pattern, the number of layer and so on, of structure. Therefore spherical space frame with triangle network pattern have attracted many designers and researchers attention all over the world. The number of layer of space frame is divided in to the simgle, double, multi layer. That is important element which is considered deeply in the beginning of structural design. The buckling characteristics of single-layer model and double-layer model for the spherical space frame structure with triangular network pattern are evaluated and the buckling loads of these types are compared with investigation their structural efficiency in this study.

• Journal of Korean Association for Spatial Structures
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• v.13 no.2
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• pp.75-82
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• 2013

For each cable component in a cable dome structure, pre-tension is needed for stability of whole the structure. The summation of these pre-tension at each joint should be zero to achieve the self equilibrium structure. The first step in cable dome structure analysis is to find the ratio of pre-tension in each member which can produce a stable and structure on self-equilibrium. In this paper, a new method based on the basic principle of closed force polygon for equilibrium system is proposed for the determination of self-equilibrium mode of cable dome structure. A single layer cable dome and two multi layer type domes have been analyzed. The ratios of cable members are determined by the presented method, and check the validation of the results by numerical calculation.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1508-1510
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• 2009

In this work, we have compared OLED devices made of blended MEH-PPV/Ruburene mixture and MEH-PPV/Rubrene bi-layer structure devices. The emission layers were made with two different ways - one with gravure printed single layer of blended mixture of MEH-PPV and rubrene, the other with gravure printed bilayers of MEH-PPV and rubrene. Both brightness and efficiency with gravure printed bi-layer devices were higher than blended devices. In this work, we demonstrated that organic bi-layers can be formed with gravure printing technology and higher efficiency can be achieved with bi-layer structure than with blended single layer structure.

• Journal of Korean Association for Spatial Structures
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• v.14 no.1
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• pp.51-59
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• 2014

Single layer free-form structures are being highlighted in the field of architecture due to its attractive shape. In these structures, node connecting system is very important because the node must resist bending and axial stress simultaneously. So the local and global stabilities of entire structure can be determined by the stiffness of node system. In this study, therefore, various types of bending test with axial force were performed. As a result, bending capacity with axial force of a new spherical node for free-form structure could be performed and structural capacities were checked to use in real structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.44-48
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• 2008

Hole mobility characteristics of two representative biaxially strained SiGe/Si structures with high Ge contents are studied, They are single channel ($Si/Si_{1-x}Ge_x/Si$ substrate) and dual channel ($Si/Si_{1-y}Ge_y/Si_{1-x}Ge_x/Si$ substrate), where the former consists of a relaxed SiGe buffer layer with 60 % Ge content and a tensile-strained Si layer on top, and for the latter, a compressively strained SiGe layer is inserted between two layers, Owing to the hole mobility performance between a relaxed SiGe film and a compressive-strained SiGe film in the single channel and the dual channel, the hole mobility behaviors of two structures with respect to the Si cap layer thickness shows the opposite trend, Hole mobility increases with thicker Si cap layer for single channel structure, whereas it decreases with thicker Si cap layer for dual channel. This hole mobility characteristics could be easily explained by a simple capacitance model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.427-430
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• 2003

The properties of digital X-ray detectors depend on the absorption extent of X-rays, the generated signal of each X-ray photon and the distribution of the generated signal between pixels. In digital X-ray detector with single layer, signal is generated by X-ray photon captured in photoconductor. In X-ray detector with multi structure that scintillator formed above the top of photoconductor, signal is generated both by X-ray photon captured each in scintillator and photoconductor. X-ray detector with multi structure is generated more signal than single layer detector. In this paper, we simulated absorption fraction of X-ray detector with multi-layer using Monte Carlo program. The results compared with single-layer detector to be formed scinillator or photoconductor.