• Journal of the Korean Ceramic Society
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• v.32 no.7
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• pp.853-857
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• 1995

ZrSiO4 powders were prepared from partially hydrolyzed solution of Si(OC2H5)4 and ZrOCl2.8H2O solution by the sol-gel method and formation rate of ZrSiO4 on the reaction parameter was investigated. In order to prepare homogeneous ZrSiO4 precursor gels, the H2O/Si(OC2H5)4 molar ratio of about 2, the pH of the ZrOCl2.8H2O solution fo about 4 and stirring time of the mixed solutions of about 2 hrs were appropriate. Formation of temperature of ZrSiO4 reduced about 15$0^{\circ}C$ by milling and formation of ZrSiO4 at 1300~135$0^{\circ}C$ showed an accelerative increase through the hedvall effect by silica.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.299-299
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• 2022

Whole wheat is rich in dietary fiber and contains various biological activity substances such as arabinoxylan, phytic acid and phenolic compounds. However, excessive fiber contents of whole wheat has a negative effect on dough formation, making it difficult to process. In this study, we tried to improve the usability of whole wheat by suggesting an appropriate degree of purification of whole wheat from 'Saekeumkang', a domestic wheat cultivar containing protein and gluten suitable for noodle production. The contents of arabinoxylan, phytic acid, and vitamin E were measured in the polishing rate range of 5-20% of whole wheat flour. As the milling ratio increased, the flour properties improved. The arabinoxylan and phytic acid content of whole wheat were 67.95 mg/g and 0.87 mg/g, but when milled at 20%, arabinoxylan and phytic acid were 60% and 80% of whole wheat, respectively. And as the milling ratio increased, the vitamin E content tended to decrease (whole wheat: 4.063 mg/100 g, 20% milled: 2.96 mg/100 g), However, the vitamin E composition ratio did not change. On the other hand, α-tocopherol showed the greatest than other vitamin E isomers. Therefore, further studies needed to optimize milling rate to improve the final product while maintaining the approximate nutritional and functional value of the whole wheat.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.26-33
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• 2002

Die Factory follows typical order adaptive manufacturing, and delaying delivery affects directly product development of customer, Manufacturing Management System is tried to comply with the appointed date of delivery. It acquires running signal from NC milling, calculates manufacturing results, and offers the basic data to manage the operation ratio. Thus it offers Production data necessary to accomplish the objective of progress improvement for Unmanned Manufacturing. Manufacturing Management System runs on Web Environment, and is composed of electronic work order, operation ratio data acquisition and totaling module.

• Korean Journal of Materials Research
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• v.25 no.8
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• pp.386-390
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• 2015

Fe-base superalloy powders with $Y_2O_3$ dispersion were prepared by high energy ball milling, followed by spark plasma sintering for consolidation. High-purity elemental powders with different Fe powder sizes of 24 and 50 mm were used for the preparation of $Fe-20Cr-4.5Al-0.5Ti-O.5Y_2O_3$ powder mixtures (wt%). The milling process of the powders was carried out in a horizontal rotary ball mill using a stainless steel vial and balls. The milling times of 1 to 5 h by constant operation (350 rpm, ball-to-powder ratio of 30:1 in weight) or cycle operation (1300 rpm for 4 min and 900 rpm for 1 min, 15:1) were applied. Microstructural observation revealed that the crystalline size of Fe decreased with an increase in milling time by cyclic operation and was about 15 nm after 3 h, forming a FeCr alloy phase. The cyclic operation had an advantage over constant milling in that a smaller-agglomerated structure was obtained. The milled powders were sintered at $1100^{\circ}C$ for 30 min in vacuum. With an increase in milling time, the sintered specimen showed a more homogeneous microstructure. In addition, a homogenous distribution of Y-compound particles in the grain boundary was confirmed by EDX analysis.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.123-130
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• 2009

To understand the formation of core-shell structure in $BaTiO_3$ (BT) grains in multilayer ceramic capacitors, specimens were prepared with BT powders mixed with Y and Mg, and their microstructures were investigated with scanning electron microscopy, x-ray diffractometry, and transmission electron microscopy. Microstructural investigation showed that Y dissolved easily in BT lattice to a certain depth inside of the grain, whereas Mg tended to stay at grain boundaries rather than become incorporated into BT. It was considered that in case of Y and Mg addition in a proper ratio, Y could play a dominant role in the formation of shell leading to a slight dissolution of Mg in the shell. Next, the effects of ball-milling conditions on the core-shell formation were studied. As the ball-milling time increased, the milled powders did not show a significant change in size distribution but rather an increase of residual strain, which was attributed to the milling damage. The increase in milling damage facilitated the shell formation, leading to the increased shell portion in the core-shell grain.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.3
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• pp.269-275
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• 2014

Conventional machining technologies such as a milling process have limitations in accuracy to fabricate microstructures. Deep X-ray lithography using the synchrotron radiation is a promising micromachining process with an excellent accuracy, whereas there are difficulties in the fabrication of multi-layered structures. Therefore, it is mainly used for fabricating simple mono-layered microstructures with a high aspect ratio. In this study, a novel technology for fabricating multi-layered microstructures is proposed by combining two processes. In advance, an X-ray resist material is cut and machined into various shapes and heights by the micro milling process. Subsequent X-ray irradiation process facilitates the fabrication of multi-layered microstructures. The proposed technology can overcome the limitation of the pattern accuracy in conventional milling process and the difficulty of the multi-layered machining in x-ray process. The usefulness of the proposed technology is demonstrated in this study by applying the technique in the realization of various multi-layered microstructures.

• Corrosion Science and Technology
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• v.21 no.6
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• pp.445-453
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• 2022

SiO_x was prepared from a mixture of Si and SiO₂ via high-energy ball milling as a negative electrode material for Li-ion batteries. The molar ratio of Si to SiO₂ as precursors and the milling time were varied to identify the synthetic condition that could exhibit desirable anode performances. With an appropriate milling time, the material showed a unique microstructure in which amorphous Si nanoparticles were intimately embedded within the SiO₂ matrix. The interface between the Si and SiO₂ was composed of silicon suboxides with Si oxidation states from 0 to +4 as proven by X-ray photoelectron spectroscopy and electrochemical analysis. With the addition of a conductive carbon (Super P carbon black) as a coating material, the SiO_x/C manifested superior specific capacity to a commercial SiO_x/C composite without compromising its cycle-life performance. The simple mechanochemical method described in this study will shed light on cost-effective synthesis of high-capacity silicon oxides as promising anode materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5384-5393
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• 2015

We investigated the effects of milling degrees of rice on characteristics of the steamed rice and fermentation of rice koji as a raw material of cheongju. It was studied for 8 months about ratio of water absorption and koji charateristics according to milling degrees. The The more increasing rice milling, the less the protein contents of milled rice was continuously decreased and the lipid and ash contents were sharply decreased to until the milling degrees 20%, and then gradually decreased. When steeping the milled rice, higher milling degrees raised rapid water asorption and higher maximum water asorption, lower water temperature raised gradual water absorption and higher maximum absorption. The longer steeping time, the steamed rice milling degrees 40% showed significantly lower hardness and springness than others. Alcohol contents of the fermented mash with rice koji milling degrees 10% was lower with 16.3-16.9%(v/v) than other sample's 17.1-17.5% (v/v). The total acid contents showed that the milling degrees 10% indicated the lowest content(0.71-0.76%) and the milling degrees 30% indicated highest content(0.93-0.99%). Within the same milling degrees, As the steeping time increases, the total acid contents imcrease. In conclusion, the milling degrees influenced on physicochemical chatacteristics of rice and steamed rice condition.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1997.06c
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• pp.194-201
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• 1997

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.12a
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• pp.343-350
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• 1998