• Journal of Dairy Science and Biotechnology
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• v.23 no.1
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• pp.27-37
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• 2005

The development of functional foods started booming from several years ago in the world. The size of functional materials are in the range of micrometer level. This size can be much smaller into nanometer level to be more effective. We face some problems from the materials, such as flavor, taste, color, viscosity, etc. in functional materials. The problems can be solved by micro / nanoencapsulation technique. This paper showed some results of the research related on the technique for functional milks and dairy products. The nono / microcapsules are the form of liquid instead of solid. Coating materials used were fatty acid esters, and core materials were lactase, iron, ascorbic acid. isoflavone, and chitooligosaccharide. The ranges of capsules are from 100 nm to 200 ${\mu}$m. The sample milks added nano/microcapsules were homogeneous and prevented the defects of core materials. It was observed that nano / microcapsules in milk and dairy products were effective as functional material without defaults. It was indicated that targeted functional foods can be developed further in various foods by nanotechnology.

• Electronic Materials Letters
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• v.14 no.6
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• pp.657-668
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• 2018

Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.182-189
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• 2004

The application of adhesively bonded components is increasing in various industries such as automobile, aircraft, IC packages, and soldering techniques. In spite of such wide application in adhesively bonded components, nondestructive test techniques applying to adhesively bonded components have not been clearly established yet. In this paper, characteristics of ultrasonic test on interfaces of adhesively bonded components have been investigated by calculating transmission coefficient theoretically and experimentally. From the experimental results, the optimum conditions to establish frequencies for adhesively bonded homogeneous and dissimilar components are 4∼6 MHz and 2∼4 MHz, respectively.

• Transactions of Materials Processing
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• v.15 no.7 s.88
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• pp.479-484
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• 2006

The evolution of strain states and textures during rolling with various conditions was investigated by finite element method (FEM) simulations and measurements of rolling textures. Symmetrical rolling with a high friction gives rise to a strong variation of shear strains in rolled sample leading to the formation of texture gradients throughout the thickness layers. A small variation of shear strains during rolling with a well lubrication condition leads to the formation of a fairly homogeneous rolling texture throughout the sheet thickness. During asymmetrical rolling, a proper control of rolling parameters provides the evolution of a fairly homogeneous shear texture throughout the whole sheet thickness.

• Advances in materials Research
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• v.8 no.4
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• pp.313-335
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• 2019

The objective of the present paper is to investigate the bending and free vibration behavior of functionally graded material (FGM) sandwich rectangular plates using an efficient and simple higher order shear deformation theory. Unlike other theories, there are only four unknown functions involved, as compared to five in other shear deformation theories. The most interesting feature of this theory is that it does not require the shear correction factor. Two common types of FGM sandwich plates are considered, namely, the sandwich with the FGM facesheet and the homogeneous core and the sandwich with the homogeneous facesheet and the FGM core. The equation of motion for the FGM sandwich plates is obtained based on Hamilton's principle. The closed form solutions are obtained by using the Navier technique. A static and free vibration frequency is given for different material properties. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Transactions of Materials Processing
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• v.6 no.5
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• pp.435-445
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• 1997

In order to study the manufacturing possibility of connecting rod by direct quenching method, the difference between connecting rod by direct quenching and that by general heat treatment were investigated by observing microstructure, by measuring mechanical properties, by conducting fatigue testing, and by measuring the amount of tool wear in actual cutting. Connecting rod manufactured by direct quenching had better fatigue life than that by general heat treatment, which was due to homogeneous microstructure, and higher strength. The amount of cutting tool wear of connecting rod by direct quenching was higher than that by general heat treatment, which was due to low machinability and high toughness of tempered martensite microstructure. Therefore it will be added the study of heat treatment and cutting condition for manufacturing by direct quenching.

• Journal of Plant Biology
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• v.38 no.3
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• pp.281-288
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• 1995

The progressive differentiation of interfascicular cambium from residual meristem in the first internode of Ginkgo biloba seedlings was elucidated by light and electron microscopy. The cells of residual meristem were small and homogeneous and heterogeneous in their arrangement but those of the adjacent cortex and pith were large and homogeneous. Some interprocambial residual meristem progressively became elongated and vacuolated during the process of the differentiation. In tangential section, residual meristem composed of long and short cells. The eventual interfascicular cambium had long fusiform initials and short ray initials. Storage materials in the cells progressively disappeared from the interprocambial residual meristem and were absent in early interfascicular cambium. Both the radial and tangential walls of cells of the interprocambial residual meristem were almost the same, but the radial wall became progressively thicker than the tangential wall during differentiation of interfascicular cambium. From these results, it is clear that interfascicular cambium is gradually differentiated from residual meristem.

• Journal of the Korean Ceramic Society
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• v.32 no.10
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• pp.1212-1218
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• 1995

Al2O3-coated SiC composite powder and mechanically mixed Al2O3-SiC composite powder were synthesized using Al-isopropoxide and commercial SiC as the starting materials. Experiment results showed that the sinterability of Al2O3-coated SiC composite powder was more improved than the mechanically mixed Al2O3-SiC composite powder by the effect of homogeneous coating of alumina around SiC particles. Hence, the mechanical properties of the former was also much more improved than the latter.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1908-1912
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• 2008

Conductive polymers, prepared by mixing electrically conductive fillers with a suitable polymeric formulation, are widely used in applications such as interconnecting materials for high density electronic packaging. However, resins of conductive pastes used as binders and vehicles are generally nonconductive, so that they may prevent the electrical contact between conductive fillers and reduce electron transmission. In this study, we improved conductivity of silver paste by the incorporation of cabon nanotubes. It is important to achieve homogeneous dispersion of CNTs to act as reinforcements efficiently in matrix. We carried out acid treatment on nanotubes for their homogeneous dispersion in silver/conducting polymer matrix. The dispersion states of nanotubes were characterized by raman spectra and filed emission scanning electron microscope. The electrical resistivity of CNTs incorporated silver paste was also measured by 4-point probe method.

• Steel and Composite Structures
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• v.11 no.6
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• pp.489-504
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• 2011

This paper presents a theoretical investigation in free vibration of sigmoid functionally graded beams with variable cross-section by using Bernoulli-Euler beam theory. The mechanical properties are assumed to vary continuously through the thickness of the beam, and obey a two power law of the volume fraction of the constituents. Governing equation is reduced to an ordinary differential equation in spatial coordinate for a family of cross-section geometries with exponentially varying width. Analytical solutions of the vibration of the S-FGM beam are obtained for three different types of boundary conditions associated with simply supported, clamped and free ends. Results show that, all other parameters remaining the same, the natural frequencies of S-FGM beams are always proportional to those of homogeneous isotropic beams. Therefore, one can predict the behaviour of S-FGM beams knowing that of similar homogeneous beams.