• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.91-92
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• 2022

This study is a basic study on carbonation curing technology of concrete using supercritical CO₂, and carbonation curing was carried out by exposing concrete to supercritical CO₂ for a certain period of time. In the case of conventional carbonation curing, long-term curing was performed for several weeks by controlling the concentration of CO₂, but by using supercritical CO₂, more rapid carbonation curing was carried out using constant temperature and pressure conditions to improve durability through surface modification of concrete. This experiment was conducted with the goal of deriving the optimal carbonation curing conditions by measuring the carbonation depth by exposing concrete for a certain period of time to conditions above the supercritical level. As a result, it was confirmed that the carbonation depth increased as the curing time increased, and the curing time could be shortened compared to the carbonation curing according to the existing CO₂ concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.811-815
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• 2006

The objective of this study was to evaluate the effect of electric fan installation for milk production improvement of dairy cattle in Thailand. The study was conducted using 2 small-holder dairy farms in Chiang Mai province, during April to August 2004. Electric fans were installed in front of each row of cows. Each of the two rows of cows in the barn was defined as an experimental unit, thus each farm had two experimental units. The fans were operated alternately in 7-day intervals between rows of cows within each farm during the day or between 8.00 am to 8.00 pm. Non-operation periods were used as control. Milk yields were recorded. Data on environmental temperature and humidity were obtained from Chiang Mai Meteorological Center. Result from statistically analysis of milk record suggested an interaction between lactation period and fan installation. Therefore, this interaction term of lactation period and fan installation (PERIOD_FAN) was added as a variable to the regression model. Due to the repeated data collection of milk yield from the same cow (alternate week), milk yield was analyzed by repeated measure analysis (Mixed model). Least square means were calculated for all levels and used to compare between each pair-wise values. The final data were collected from the total of 18 cows with 2,072 data. Overall means and SEM of milk yields and days in milk separated into farm were $14.7{\pm}0.06kg/day$ and $176.3{\pm}2.2days$, and $15.2{\pm}0.22kg/day$ and $202.5{\pm}3.7$ days for farm A and farm B, respectively. For multivariable analysis, only PERIOD_FAN and humidity were significantly associated with milk yield. Only the first period of lactation showed that the amount of milk yields during fan installation was higher than that of non-fan installation (p<0.05). Cows with fan installation produced approximately 1.2 kg/cow more milk than cows without fan installation during this period. In conclusion, the use of electric fan operated during the day time increased milk production of cows during the first period of lactation.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.568-571
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• 1998

The conformations of human insulin precursors, proinsulin and preproinsulin, are described in terms of molecular dynamics simulations. Despite the presence of the C-peptide and/or the signal peptide, molecular dynamics calculations utilizing the hydration shell model over a period of 500 ps indicate that the native conformations of the A and B chains are well conserved in both cases. These results further support the NMR spectroscopy results that the C-peptide is relatively disordered and does not influence the overall conformation of the native structure. The robustness of the native structure as demonstrated by experiment and simulation will permit future protein engineering applications, whereby the expression or purification yields can be improved upon sequence modification of the C-peptide and/or the signal peptide.

• Journal of the Semiconductor & Display Technology
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• v.5 no.2 s.15
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• pp.37-39
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• 2006

We employed in-situ spectroscopic ellipsometry(SE) and imaging ellipsometry(IE) to study the interaction of water and photoresist(PR) in 193 immersion lithography. Real time measurement of SE showed thickness increase when PR was immerged in water indicating swelling effect. From the temporal evolution we could observe its reaction-limited behavior. Meanwhile, IE could identify the modification of PR surface by contact of water even for a short period of a second.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.358-358
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• 2006

The graft copolymerization of methyl methacrylate (MMA), butyl acrylate (BA) and acrylamide (AAm) onto oil palm empty fruit bunch (OPEFB) fiber were successfully carried out in aqueous solution using $H_{2}O_{2}/Fe^{2+}$ as initiator. For all monomers the percentage of grafting increases with the amount of monomer and can be controlled by setting the appropriate reaction conditions. The optimum reaction period were found to be 120 minutes for all monomers whereas the optimum temperature and the amount of initiator needed for grafting depend on the type of the monomer used. The mechanisms of grafting vinyl monomer onto OPEFB were proposed. The grafted products were characterized by gravimetric analysis, FTIR and SEM.

• Progress in Superconductivity and Cryogenics
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• v.19 no.2
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• pp.14-18
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• 2017

This study presents three dimensional (3-D) seeding technique which is a modification of interior seeding. 3-D seeding is beneficial for shortening the processing period and enhancing the magnetic properties of REBCO bulk superconductors fabricated by melt growth. Oxygen channels were provided by using divided powder compacts instead of by using a rubber insert. Microstructure observations revealed that the grains grown from the seeds impinged each other and formed low angle grain boundaries of (001)/(001). It has been shown that the 3-D seeding technique reduces the volume fraction of a-c growth sector and thereby maximizes the area of a-b growth sector which attribute to the high magnetic characteristics of single grain REBCO bulk superconductors.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.1-10
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• 2000

우리 나라의 주거 건물의 많은 부분을 차지하는 조적조 건물은 저층이므로 내진 설계에 대한 지침이 마련되어 있지 않다. 그러나 조적조 건물의 경우 저층이라 하더라도 구조특성상 수평하중에 대한 저항능력이 매우 약하므로 내진 설계에 대한 기준이 요구된다. 일반적으로 내진설계 시 동적 해석을 수행하면 많은 시간이 소모되므로 실무자들에게 등가정적해석법을 제시하여 내진설계 시 편의를 제공하고 있다. 그러나 저층 조적조 건물은 일반적인 건물과는 거동 특성이 다르므로 저층 조적조 건물에 적용할 수 있는 해석법을 제시하고자 한다. 본 논문에서는 개구부의 비율에 따른 조적벽의 연성도, 강도 및 고유주기를 구하여 반응수정계수와 고유주기를 비교하여 우리 나라의 조적조 건물에 적합한 반응수정계수와 고유주기 산정식을 제안하였다.

• Fibers and Polymers
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• v.4 no.4
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• pp.210-214
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• 2003

Siloxylated polypropylene fibers composed of polypropylene (PP) and aluminosiloxane (AS) were prepared by melt blending followed by spinning. The effects of blend compositions on the thermal behaviors, surface and tensile properties of PP/AS blend fibers were investigated by DSC, WAXD, SEM, static honestometer, etc. The heat of fusion of PP/AS blends decreased with increasing AS contents. In addition, the peak intensity of PP/AS blends in X-ray diffraction patterns decreased with increasing AS contents. It was observed that the silicone molecules exist and well distribute on the surface of siloxylated polypropylene fibers. From the results of the half-life period measurements, the anti-static properties of PP fibers siloxylated with AS was found to be significantly modified.

• International Commerce and Information Review
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• v.9 no.2
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• pp.467-480
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• 2007

This research empirically examined changes in the images of Korea over three points in time among Japanese, Chinese, and U.S. visitors to South Korea. Between March 14 and May 31, 2005, about two to three months after the 2005 Seoul International Sports & Leisure Industry Show ended, 153 tourists from America, 129 from China, and 156 from the Japan completed the survey instrument. The results from a General Linear Model (GLM) with repeated measures showed that tourists from all three countries had more positive images after the Seoul International Sports & Leisure Industry Show than before it. It was concluded that the 2005 Seoul International Sports & Leisure Industry Show appeared to have a significant positive effect in enhancing the image of South Korea. The study suggests that an internationally significant trade Show can change the image of a tourism destination in a short time period.

• Journal of the Korean Society of Costume
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• v.32
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• pp.83-100
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• 1997

The purpose of this study was to identify the change and characteristics of 20th Korean women's make-up the result of the study as follows: In the period 1920's 1. The drastic social changes such as civilzation and revolution together with the in troduction of western culture affected make-up and clothes. New women and high school girls wore the modified costume make-up hair style But general public women keep to traditional skin care style and white skin colour was popular. 2. In recent year after 1960's economic de-velopment the women's social status were pormoted after 1970's various colour em-phasize lip eye there by resulting in remark-able modification in the Korean women's apperance. In those days there was the large cosmetic producst of vavious colour 3. The result of this study indicated that the value of recognize the importance of total fashion is the harmonization of clothes and make-up 4. It was also suggested Korean beauty in the future should be achieved in accordance with tradition and modern sense.