• Steel and Composite Structures
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• 제38권1호
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• pp.79-86
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• 2021

Due to the complex geological conditions, a large number of high quality coal seams was buried in the western of China which cannot be mining in open-pit methods. The dynamic properties of that coal cannot be studied easily in real site for the complex working condition. The compound coal blocks made on the basis of the real situation were studied in the laboratory. The physical and mechanical properties of the compound coal blocks and the raw coal were contrasted by using the UCS tests. The results show that the compound coal blocks made by mixing coal powder, cement and water in proportion of 2.5:2:1 are the closest to that of standard raw coal. Then the propagation of strain waves and crushing effects on the coal were studied in the compound coal blocks by using the super dynamic strain test system and the numerical calculated method of ANSYS/LS-DYNA. The results show that the diameter of the crushing zone in the compound coal blocks was similar to that in the numerical results. The fractures distribution in laboratory tests also has a similar trend to the calculation results. The measured strain waves at the distance of 50 cm, 100 cm, and 150 cm from the center of the charge are mainly concerned at -1.0×104 με and have a similar trend as that in the numerical simulation.

• 건축역사연구
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• 제31권6호
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• pp.7-16
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• 2022

Traditional Korean architecture and traditional ships maintained a close relationship with carpenters and tools because wood, the material, was common. This close relationship may have been from the time of ancient architecture and ancient ships. In previous studies, researchers proved the relationship between these two sides through historical records of traditional architecture and traditional ships. This study attempts to prove the structural association using existing remains. As a result, three structural similarities between traditional architecture and traditional ships could be found. First, the types of wood used are similar, and the tools and terms used are similar. Second, the method of distinguishing horizontal and vertical materials and the structure of wood and the method of forming wood are similar. Lastly, the ship carpenters mobilized for the construction of the palace mainly worked on long and curved materials such as the eaves and the ridge of a roof, because this was the work done when the ship was built. Therefore, it can be assumed that the roof structure they created resembles that of the ship.

• 한국동물위생학회지
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• 제36권4호
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• pp.273-281
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• 2013

This study investigated the effects of the alkaline detergent and acid rinse used for cleaning milking machines on the eight commercially available teatcup liner materials. The sample liners prepared for use in the clean-in-place process were analyzed by ultraviolet spectrophotometer, ion chromatography and liquid chromatography. Among the eight liner materials, the ultraviolet spectra of 3 sample liners were shown to have a similar peak shape after cleaning, but the ultraviolet spectra peak shape of 5 sample liners was noticeably changed. No products were detected by ion chromatography in any of the liner materials used in this study. When the liner materials were only treated with alkaline detergent, some additional peaks were observed using liquid chromatography which indicate the creation of molecular substance and elution from liner materials, however, these peaks disappeared when the liner materials were cleaned with the acid rinse. Therefore, we propose that an acid rinse should be applied, after cleaning the milking machine with the alkaline detergent.

• 한국재료학회지
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• 제17권10호
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• pp.521-525
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• 2007

The microstructure and mechanical properties of an oxygen free copper processed by accumulative roll bonding(ARB) at low strain rate were studied. The copper sheets were highly strained up to an equivalent strain of ${\sim}6.4$ by ARB process at ambient temperature. The strain rate of the copper during the ARB was $2.6sec^{-1}$. The microstructure and mechanical properties of the ARB-processed copper were compared to those of the specimens processed by ARB at relatively high strain rate ($37sec^{-1}$). The microstructure and mechanical properties of the copper with ARB process was very similar to each other despite of some differences in recovery.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.76-79
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• 2000

Polymeric composites exhibit highly nonlinear and rate dependent behavior during loading and unloading in off-axis directions. The equilibrium state of stress during loading is lower than the state of stress produced at finite strain rates. The amount of stress relaxation during loading decreases. Interestingly, however, the stress goes up to reach to the equilibrium state of stress for a fixed displacement during unloading. The unloading behavior is quite similar to the loading behavior. The stress relaxation patterns during loading and unloading is also similar, and those depend on the fiber orientation angles and the loading and unloading rates. The AS4/PEEK thermoplastic composite is used to characterize the relaxation behavior for different off-axis angles and loading rates. There exists a transient loading region at the beginning of unloading. The effective stress and effective plastic strain concept is used to establish a master curve of stress recovery pattern for different off-axis angles and unloading rates.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.443-446
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• 2005

Recently, according to increase use of concrete which is the main material of construction, the natural aggregate of good quality is more and more decreased. Most of all, among the concrete materials, the development of alternation materials of sand is urgently needed. In this study, investigating the production equipment and the sample of crushed sand company and analyzing properties of sand, manufactured mortar by the KS to use crushed sand as the fine aggregate of concrete material. The experiment result is as follows. 1. The density, an absorptivity, and the amount of 0.08mm passage ratio of crushed sand, and the mortar used crushed sand satisfied KS. The mechanical results is similar to sea sand. 2. The crushed sand which used impact crusher instead of cone crusher for 3rd or 4th crusher was similar properties to sea sand, so it is judged that impact crusher has high effect of particle shape improvement of crushed sand.

• 한국생산제조학회지
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• 제21권5호
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• pp.697-701
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• 2012

Numerical modeling for a coke dry quenching process was developed and evaluated. The cokes had similar characteristics to a porous material, therefore, its quenching analysis was simplified as a cooling process of porous blocks. A uniform inlet temperature and constant properties of materials in the oven were also assumed. With given operating conditions, temperature profiles in the cokes were calculated and compared to the actual values. The calculated temperature gradient was high at the upper part of the coke flow and the cooling rate decreased as cokes came down to the exit port. The exit port temperature of cokes was similar to the measured value, however, temperature-dependent material properties and operating conditions must be considered to predict the temperature precisely. The calculated results could be applied to design a coke oven to produce high quality cokes.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 2000년도 Proceedings of 2000 International Nano Crystals/Ceramics Forum and International Symposium on Intermaterials
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• pp.127-142
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• 2000

The charged cluster model states that chemical vapor deposition (CVD) begins with gas phase nucleation of charged clusters followed by cluster deposition on a substrate surface to form a thin film. A two-chambered CVD system, separated by a 1-mm orifice, was used to study gold deposition by thermal evaporation in order to determine if the CCM applies in this case. At a filament temperature of 1523 and 1773 K, the presence of nano-meter sized gold clusters was found to be positive and the cluster size and size distribution increased with increasing temperature. Small clusters were found to be amorphous and they combined with clusters already deposited on a substrate surface to form larger amorphous clusters on the surface. This work revealed that gold thin films deposited on a mica surface are the result of the sticking of 4-10 nm clusters. The topography of these films was similar to those reported previously under similar conditions.

• 식물병연구
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• 제17권2호
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• pp.148-154
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• 2011

본 연구는 당근의 유기재배를 위하여 13개의 친환경 제제를 이용한 당근의 Alternaria spp.에 의한 종자전염성 병원균 방제 및 종자 발아율 조사를 수행하였다. 병원균의 생장억제 효과는 친환경 제제 별로 차이를 보였으며 효과가 좋은 7개 제제를 선발하였다. 7개 친환경제제별종자소독 후 발아율 조사에서는 식물 추출물인 탄저스탑과 랜드세이버 제제로 소독된 종자는 발아가 전혀 되지 않았으며 다른 친환경제제에서 소독된 종자의 발아율은 대조약제(Benlate-T)와 무처리 종자의 발아율과 비슷하였다. 탄저스탑과 랜드세이버를 제외시킨 감염율 조사에서는 A. radicina 균에 대한 해조류 추출물인 벨로퍼, A. dauci 균은 식물 추출물인 씨알-100으로 소독된 종자가 감염율이 10% 미만으로 대조약제와 비슷하거나 낮게 나타났다. 이들 제제는 뿌리길이 및 유묘검정 발아율 조사도 대조약제로 소독한 종자와 비슷하거나 우수한 것으로 조사 되었다. 본 시험의 결과로 보아 종자소독의 최적의 조건은 약제별 농도에 따라 다소 다르며 친환경 제제를 이용한 종자소독은 종자전염성 병원균을 효과적으로 억제할 수 있는 기술로 활용될 수 있다.

• 한국의류학회지
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• 제34권2호
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• pp.318-335
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• 2010

This study is to enhance the competitiveness of the domestic cosmetic industry and provide basic materials needed for a design idea by analyzing perfume bottles designed by Rene Lalique. The methods of this study are documentary research and demonstrative research. The documentary research considered the theoretical background with a focus on related domestic and international literature, previous research, and Internet materials. The demonstrative research extracted photo materials of the bottle designs of Lalique from domestic and international web sites along with literature that classified them into shapes, colors, materials, and patterns that analyzed the general characteristics and chronologic changes. The results of this study are as follows. The curve-oriented shape was common and multi-colors were used more frequently than a single color in the 1910's. Colorless-transparent glass and a flower patterns were used frequently for materials and patterns, respectively. Lalique reflects this style in his bottle designs because the Art Nouveau effect in the 1910's. In the 1920's, curved and straight shapes had a similar percentage. The use of multi-colors and one type of glass bottle increased versus the 1910's. Similar to the 1910's, a flower pattern was used most frequently. This suggests that Lalique was influenced by the established Art Nouveau and was also interested in the Art Deco style, In the 1930's, an organic curved shape was common. Unlike the 1910's and 1920's, a single color was more common than multi-colors. The one type of glass bottle and a geometric pattern were common for materials and patterns, respectively. The Art Deco style was reflected in the bottle design of Lalique in the 1930's.