• 한국공작기계학회논문집
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• 제15권6호
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• pp.22-31
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• 2006

When ironwork, especially steel roll coil, is transported to customers, land transportation and sea transportation are usually used. To transport steel roll coil fast and safe without damaging it, it is necessary that the steel roll coil has to be in stable condition. These days, apitong, which is all imported from overseas, is being used to support the steel roll coil, but because of apitong's rigidity, it damages the coil and when the coil is damaged, it is hard to fix. Due to the fact that recovering damage of the coil is almost impossible, we have to find the new type of dunnage that can substitute the apitong. In this paper, the arrays and the kinds of reinforcements, and rectangular type and trapezoid of dunnage will be talked about. The phenomenon of rolling and the impact when the carrier start moving and stop will be talked about as well. Therefore, we are going to develop a dunnage that does not damage ironwork and has better recovery and softness than existing apitong dunnage.

• 한국식품영양학회지
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• 제20권2호
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• pp.103-107
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• 2007

Elsholtzia spp., a herbaceous perennial plant grown worldwide, have been used as a folklore medicine. Due to the presence of flavonoid in their extracts, Elsholtzia spp. have various functional properties. The objective of this research was to compare the amount of flavonoids in Elsholtzia spp. extracts in order to improve the potential of by using their functional properties. Elsholtzia spp. were collected in various areas of Korea. These were divided into leaf, flower, stem, and root. Each sample was dried using various drying method and ground to a powder. The powdered sample prepared was extracted with 80% ethanol. Extracts were analysed for the content of total flavonoids and apigenin by HPLC. Higher content of flavonoids was observed in the extracts of leaves and flowers. In previous study, apigenin among flavonoids was detected from Elsholtzia spp. so, apigenin content was analysed by HPLC. According to the results, the extracts of leaf and flower had the higher apigenin content than other samples.

• Food Quality and Culture
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• 제3권1호
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• pp.6-10
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• 2009

This study examined the effects of adding Pleurotus ostreatus, Agaricus bisporus and Flammulina velutipes on the quality characteristics of cookies and multiple purposes of wheat powders. The water content, crude protein content, mineral content, color value and sensory evaluation of mushroom cookies and multiple purposes of wheat powders were measured. In the case of cookies, the water content was 1.10-1.24% and crude protein content was 8.20-9.80%. General preferences, such as appearance, color, taste and texture, increased when mushroom was added to the cookies, especially flavor, which showed a much higher preference. In the studies where mushroom was added to wheat powders, the water content was 0.57-0.92% and crude protein content was 11.90-12.80%. The addition of mushroom to both of the cookies and multiple purposes of wheat powders resulted in a remarkable increase in the mineral content, especially Fe, K. In addition, an increase in the amount of added mushrooms resulted in an increase in the hunter L and a values; however, this also resulted in a decrease in the b value.

• Food Quality and Culture
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• 제3권1호
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• pp.45-48
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• 2009

The investigation assessed the influence of Compositae plants consumption on the protein profile in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Sprague-Dawley rats by injection of STZ (45 mg/kg body weight) into tail vein. The rats were randomly assigned to five groups: normal and STZ-control fed an AIN-93 diet, and groups whose diets were supplemented with 10% Compositae powder containing Artemisia iwayomogi (A. iwayomogi), Atractylodes lancea (A. lancea) or Taraxacum mongolicum (T. mongolicum). To observe the effects of Compositae plants in the animal model, the levels of protein in liver, kidney, lung, pancreas, and brain were determined after 4 weeks. The level of protein in kidney increased significantly in rats receiving the A. iwayomogi- and T. mongolicum-supplemented diet compared to the STZ-control group. The level of protein in lung was increased significantly in the A. iwayomogi-supplemented group. Blood glucose level correlated well with brain protein level but did not correlate with other protein levels. Also, blood glucose correlated inversely with kidney, lung and brain protein levels. It is suggested that supplementation with A. iwayomogi in diabetic rats leads elevates protein in kidney and lung.

• 보존과학연구
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• 통권13호
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• pp.37-58
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• 1992

Iron artifacts from Busǒ Sansǒng inffered to late Baikjae periodwere studied on the aspects of metallugy. These materials were the largest size ever since excavated. From the analytical results these artifacts were found to be pureiron system without impurities or hypo-eutectoid steel system in below 0.3% in carbon contents. From the content of phosphorus in the range of 0.03∼0.05% as aim purity it was shown that charcoal were used for making these iron artifacts from sponge iron not fusion method. By observing metallugical structure it was found that iron artifacts was manufactured by repetitive folding and hammering forging method and some by heating method for adding carbon with cool water. This method were to improve the quality of the soften steel to harden one. In addition to those above repetitive hammering method eliminated the nonferrous materials such as slag inclusion and remained relatively pure ferrite.

• 대한화학회지
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• 제38권9호
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• pp.628-631
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• 1994

펄스 핵자기공명 기법을 이용하여 상자성 물질인 $CuF_2$를 조사한 결과 상온에서 $^{19}F$ 위치의 차이에 의한 확연히 구별되는 두 개의 공명선을 얻었다. 한 선은 진동수 이동이 거의 없었지만 다른 한 선은 진동수 이동이 심했다. 두 경우 모두 스핀-격자 완화시간$(T_1)$이 짧지만 진동수 이동이 심한 경우에 $T_1$ 이 더 짧았다. 이는 두 경우에 대한 주위의 전자 환경이 다르기 때문으로 해석된다.

• 한국세라믹학회지
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• 제46권5호
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• pp.447-451
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• 2009

Continuous SiC fiber-reinforced SiC composites ($SiC_f$/SiC) were fabricated by electrophoretic deposition (EPD). Nine types of slurries with different powder contents, binder resin amounts and slurry pH were deposited on Tyranno$^{TM}$-SA fabrics by EPD at 135 V for ten minutes to determine the optimal conditions. Further EPD using the optimum slurry conditions was performed on fabrics with four different pyrolitic carbon (PyC) thicknesses. The density of the hot-pressed composites decreased with increasing PyC thickness due to the difficulty of infiltrating the slurry into the narrow gaps between the fibers. On the other hand, the mechanical strength increased with increasing PyC thickness despite the decrease in density, which was explained by the enhanced crack deflection with increasing PyC thickness. The $SiC_f$/SiC composites showed the highest density and flexural strength of 94% and 342 MPa, respectively, showing EPD as a feasible method for dense $SiC_f$/SiC fabrication.

• 한국세라믹학회지
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• 제53권6호
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• pp.628-634
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• 2016

The 8 wt% yttria($Y_2O_3$) stabilized zirconia ($ZrO_2$), 8YSZ, a typical thermal barrier coating (TBC) for turbine systems, was fabricated under different starting powder conditions and coating parameters by atmospheric plasma spray (APS) coating process. Four different starting powders were prepared by conventional spray dry method with different additive and process parameter conditions. As a result, large- and small-size spherical-type particles and Donut-type particles were obtained. Dense structure of 8YSZ coating was produced when small size spherical-type or Donut-type particles were used. On the other hand, 8YSZ coating with a porous structure was formed from large-size spherical-type particles. Furthermore, a segmented coating structure with vertical cracks was observed after post heat treatment on the surface of dense structured coating by argon plasma flame at an appropriate gun distance and power condition.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.373-377
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• 2009

A pathway for the formation of normal $CoAl_2O_4$ particles is suggested. The optimal amount of malonic acid was determined, and the characteristics of the obtained powders were investigated. Normal $CoAl_2O_4$ powders were prepared using solutions of malonic acid and metal nitrates. X-ray diffraction, Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM) measurements, as well as Fourier transform infrared (FTIR) and ultraviolet/visible (UV-Vis) spectroscopy were carried out. Normal $CoAl_2O_4$ crystallites were formed by a solid state reaction between $CoAl_2O_4$ and amorphous aluminum oxide. The optimal molar ratio of malonic acid to the nitrate anions present in the initial solution was found to be 0.30~0.35. The particles were composed of agglomerates of primary particles. The primary particles were 40 nm in size. This size was relatively constant regardless of the preparation temperature. However, the size of the agglomerated particles increased to 220 nm with increasing temperature.

• 한국군사과학기술학회지
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• 제23권3호
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• pp.195-203
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• 2020

Selective laser melting(SLM) is one of the powder bed fusion(PBF) processes, which enables quicker production of nearly fully dense metal parts with a complex geometry at a moderate cost. However, the process still lacks knowledge and the experimental evaluation of possible process parameter sets is costly. Thus, this study presents a finite element analysis model of the SLM process to predict the melt pool characteristics. The physical phenomena including the phase transformation and the degree of consolidation are considered in the model with the effective method to model the volume shrinkage and the evaporated material removal. The proposed model is used to predict the melt pool dimensions and validated with the experimental results from single track scanning process of Ti-6Al-4V. The analysis result agrees with the measured data with a reasonable accuracy and the result is then used to evaluated each of the process parameter set.