• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2009.03a
• /
• pp.116-117
• /
• 2009

In this study, As a previous stage to manufacture disposable tent for military camouflage, we examine possibility of inorganic material absorption on PET surface. In order to, we created unevenness by sputtering process on PET surface and made absorption with Zirconium (ZIA) that has nano particles. and we went on study to its effect.

• 한국초전도학회:학술대회논문집
• /
• 2009.07a
• /
• pp.96-96
• /
• 2009

• Proceedings of the Korean Magnestics Society Conference
• /
• 2011.12a
• /
• pp.72-73
• /
• 2011

• Proceedings of the Korean Magnestics Society Conference
• /
• 2016.05a
• /
• pp.71-72
• /
• 2016

• Journal of the Korean Ceramic Society
• /
• v.48 no.6
• /
• pp.510-515
• /
• 2011

In this study, as a material used to replace silica fumes for high strength concrete, nano-silica compound with organic functional group for dispersion and with inorganic silica group that can cause a pozzolan reaction is synthesized, These nano silica compound is divided into IC, which is nano size $SiO_2$ with irregularly combined hydroxyl group and carboxyl group, and RC, which is nano size $SiO_2$ with regularly combined hydroxyl group and carboxyl group. The effects of these nano silica compound on the hydration of cement are reviewed. As a result, all of synthesized nano-silica compounds have excellent dispersion on the cement flow, we think that dispersion property is the effect of air entraining by synthesized nano-silica compounds. The result of the microstructure observation showed that the particle size of the synthesized nano-silica is smaller than silica fume and spread evenly among the cement particles. In initial The phenomenon of strength decreasing occurred due to delayed hydration reaction by the synthesized nano-silica with carboxyl(-COOH) and hydroxyl(-OH) functional group.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.4
• /
• pp.186-189
• /
• 2010

Nano-sized MgO single crystal powders have recently been reported to emit ultraviolet by stimulation of electrons in a vacuum. In this study, nanocrystalline MgO powders were applied to a xenon plasma flat fluorescent lamp (FFL) for a liquid crystal display backlight to improve its emission efficiency through the extra ultraviolet from the nano-MgO crystals. For comparison, a MgO nano-thin film was applied directly on the phosphors inside a lamp panel through e-beam evaporation. Adding MgO nano-crystal powders to the phosphors improved the luminance and efficiency of FFLs by around 20% and MgO nano-crystal coverage of 40% of the phosphor provided the best FFL emission characteristics; however, application of MgO thin film to the phosphors degraded the emission characteristics, even compared to FFLs without MgO. This was due to insufficient ultraviolet stimulation of the phosphors and the crystallinity and low secondary electron coefficient of the MgO.

• Journal of Welding and Joining
• /
• v.27 no.3
• /
• pp.73-79
• /
• 2009

This present paper investigated the mechanical properties and the microstructures of each penetration shapes classifying the conduction shape area and the keyhole shape area about electron beam welded 120(T)mm thick plated aluminum 5052 112H. As a result the penetration depth is increased linearly according to the output power, but the aspect ratio is decreased after the regular output power. In the conduction shape area, the Heat affected zone is observed relatively wider than the keyhole shape area. In the material front surface of the welded specimen, the width is decreased but the width in the material rear surface is increased. After the measuring the Micro Vikers Hardness, it showed almost similar hardness range in all parts, and after testing the tensile strength, the ultimate tensile strength is similar to the ultimate tensile strength of the base material in all the specimens, also the fracture point was generated in the base materials of all the samples. In the result of the impact test, impact absorbed energy of the Keyhole shape area is turned up very high, and also shown up the effect about four times of fracture toughness comparing the base material. In the last result of observing the fractographs, typical ductile fraction is shown in each weld metal, and in the basic material, the dimple fraction is shown. The weld metals are shown that there are no other developments of any new chemical compound during the fastness melting and solidification.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.273.1-273.1
• /
• 2014

Graphene, a two dimensional plane structure of $sp^2$ bonding, has been promised for a new material in many scientific fields such as physics, chemistry, and so on due to the unique properties. Chemical vapor deposition (CVD) method using transitional metals as a catalyst can synthesize large scale graphene with high quality and transfer on other substrates. However, it is difficult to control the number of graphene layers. Therefore, it is important to manipulate the number of graphene layers. In this work, homogeneous solid solution of Cu and Ni was used to control the number of graphene layers. Each films with different thickness ratio of Cu and Ni were deposited on $SiO_2/Si$ substrate. After annealing, it was confirmed that the thickness ratio accords with the composition ratio by X-ray diffraction (XRD). The synthesized graphene from CVD was analyzed via raman spectroscopy, UV-vis spectroscopy, and 4-point probe to evaluate the properties. Therefore, the number of graphene layers at the same growth condition was controlled, and the correlation between mole fraction of Ni and the number of graphene layers was investigated.

• Membrane Journal
• /
• v.23 no.2
• /
• pp.101-111
• /
• 2013

Nano materials having large surface area, uniform dimensions or pores can be utilized in various membrane applications. Recently, many studies have been focused on the application of nano materials and nano technologies in membrane applications by the help of the discovery and development of nano technologies. in terms of mass transport channels or functional modification. However, there have been several technological limitations for commercialization. Nano materials and nano technologies can improve 1) permeability, selectivity, 2) mechanical, chemical, thermal stability or fouling tolerance of conventional membranes and even 3) introduce new functionalities such as specific affinity and reactivity.

• Steel and Composite Structures
• /
• v.36 no.6
• /
• pp.631-642
• /
• 2020

This paper studies nonlinear stability behavior of a nanocrystalline silicon curved nanoshell considering strain gradient size-dependency. Nanocrystallines are composite materials with an interface phase and randomly distributed nano-size grains and pores. Imperfectness of the curved nanoshell has been defined based on an initial deflection. The formulation of nanocrystalline nanoshell has been established by thin shell theory and an analytical approach has been used in order to solve the buckling problem. For accurately describing the size effects related to nano-grains or nano-pores, their surface energies have been included. Nonlinear stability curves of the nanoshell are affected by the size of nano-grain, curvature radius and nano-pore volume fraction. It is found that increasing the nano-pore volume fraction results in lower buckling loads.