• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1127-1134
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• 2002

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutio ns of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle syntheses have been proposed.

• Elastomers and Composites
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• 제32권5호
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• pp.295-301
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• 1997

The effects of filler types and compositions on the final properties such as tensile strength, % elongation, hardness, and specific gravity of chloroprene rubber were investigated. The fillers involved in this investigation were HAF-type carbon black, Mistron, and white clay, For each filler, the variation of filler compositions gave almost the linear effects on the all properties investigated. For a fixed filler composition, different filler types gave different influential strength on rubber properties. After linearlization of experimental data with respect to each filler composition, the simple linear addition of each property with respect to filler compositions was applied to predict the final properties of the filler included rubber systems. For the chloroprene rubber system including the fillers composed of Mistron(25phr)/HAF(20phr)/clay(35phr), the predicted properties were well in accordance with the experimental results. Similar results were obtained for other additives such as processing oil and accelerator.

• 한국초전도ㆍ저온공학회논문지
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• 제5권1호
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• pp.27-30
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• 2003

The Bi2212 based HTS tubes with 4 different compositions, Bi:Sr:Ca:Cu = 2.0:2.0:1.0:2.0, 2.1:2.0:1.0:2.0,2.2:1.8:1.0:2.0 and 2.2:1.8.1.0.2:2 with 10% of SrSO$_4$ were studied. For tube fabrication the optimum range of melt temperatures and preheating temperature and time for mold were 105$0^{\circ}C$~110$0^{\circ}C$ and 55$0^{\circ}C$ for 30min respectively. The mold rotating speed was 1000rpm. Typical tube dimension was 30/24mm in outside/inside diameter and 60mm in length. A tube was annealed at 84$0^{\circ}C$ for 40 hours in oxygen atmosphere. The plate like grains more than 20${\mu}{\textrm}{m}$ were well developed along the rotating direction of mold regardless of initial chemical compositions. The specimen with Bi2212 composition exhibited $T_c$ of 83K while the specimen with other compositions are lower than 60K. The measured $I_c and J_c$ at 77K(B = 0T) in Bi2212 composition were about 80A and 266A/$\textrm{cm}^2$.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.435-437
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• 2003

In order to investigate processes and factors controlling the chemical and isotopic compositions of the Han River, seasonal studies were carried out. The North Han River was much lower in the concentrations of total dissolved solids (TDS), dissolved inorganic carbon (DIC) and major ions than the South Han River, but higher in $SiO_2$ concentration, $\delta$$^{34}$ $S_{so4}$ value and $^{87}$ Sr/$^{86}$ Sr ratio. This indicates that the chemical and isotopic compositions of the Han River were strongly controlled by the geology of their drainage basins: silicate rocks in the North Han River and carbonate rocks in the South Han River. The $\delta$$^{34}$ $S_{so4}$ values were relatively higher in the North Han River (5.90$\pm$1.46$\textperthousand$)) than in the South Han River (3.48$\pm$0.73$\textperthousand$). This implies that dissolved S $O_{4}$$^{2-}$ in the North Han River might be mostly derived from deposition of atmospheric sulfates, whereas in the South Han River from oxidation of sulfide minerals in the abandoned poly-metallic deposits and the coal-bearing sedimentary rocks distributed over the upstream as well as deposition of atmospheric sulfates. The $^{87}$ S $r^{86}$ Sr ratios in the North Han River were distinctly higher than those in the South Han River, reflecting water-rock interaction with different rock types.pes.

• Bulletin of the Korean Chemical Society
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• 제24권4호
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• pp.527-530
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• 2003

• 동아시아식생활학회지
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• 제16권2호
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• pp.186-191
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• 2006

The purpose of this research was to study the chemical compositions of pork for crossbred pig (female, 198 days old $102{\sim}118kg$) that were fed with tangerine byproduct from pregnancy through the whole rearing period. The samples for this study consisted of the pork from give the number of control pigs not fed with tangerine byproduct($T_0$), and the pork from give the number of study pigs fed with 8% tangerine byproduct during the whole breeding period, from the early pregnancy through the young, growing and finishing periods ($T_1$). Backfat thickness of the crossbred pigs was significantly decreased by feeding tangerine byproduct (p<0.05). The proximate composition, minerals, total amino acid, saturated fatty acid vs. unsaturated fatty acid and vitamin $B_2$ contents of loins were not significantly different among $T_0\;and\;T_1$, (p>0.05). Although those differences were not significant statistically, the tangerine byproduct tended to increase the amount of vitamin $B_1$, and decrease the crude fat and cholesterol contents.

• 한국강구조학회 논문집
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• 제12권6호
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• pp.649-659
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• 2000

본 연구에서는 고장력 용접구조용 압연강재인 SM570을 건축구조용으로 사용하기 위해서 판두께에 따른 화학성분과 기계적 성질의 분포특성을 정량적으로 평가하였다. 또한 건축구조용 강재로 주로 사용되는 일반구조용 압연강재인 SS400과 용접구조용 압연강재인 SM490을 비교재로 사용해서 SM570 강재와 비교 평가하였다. 본 연구결과 모든 두께에서 SM570 강재의 화학성분, 탄소당량, 용접 갈라짐 감수성 조성과 항복강도, 인장강도, 연신률 및 충격강도는 한국산업규격을 만족하였다.

• 한국식품영양과학회지
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• 제27권3호
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• pp.381-385
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• 1998

Chemical components of Perillar semen and physico-chemical properties o Perillae semen oil were analyzed for the use as an edible oil. The proximate compositions of Perillae semen were 7.5% moisture, 33.2% crude fat, 16.3% crude protein, 2.8% crude ash, 6.5% crude fiber, and 33.7% nitrogen free extract. The major amino acids of Perillae semen were glutamic acid(66.9mg%), aspartic acid (32.5mg%), histidine(21.6mg%), and phenylaanine (20.1mg%). The ratio of essential/total amino acid was 41.3%. The physico-chemical properties of the seed oil were 0.915 specific gravity, 1.4808 refractive index, 3.6 acid value, 181.7 iodine value, and 194.0 saponification value. Composition of major lipid of the oil fractionated by silicic acid chromatography was 94.2% neutral lipids and 5.8% polar lioids. The major fatty acids of the oil were linolenic, linoleic and oleic acid. Neutral lipids consisted of 59.9% linolenic acid, 15.6% oleic acid, 6.6% palmitic acid, and 2.5% stearic acid. Polar lipids consisted of 58.5% linolenic acid, 18.1% linoleic acid, 12.7% oleic acid, 7.7% palmitic acid, and 3.0% stearic acid.

• 한국결정성장학회지
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• 제1권2호
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• pp.1-14
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• 1991

비균질 용융을(incongruent melting behavior)보이는 단결정제조에 있어 화학성분을 일정성분비로 유지하는 것은 매우 어렵다. $LiNbO_3$는 이러한 성질을 보이는 대표적인 예인데 넓은 고용(固溶)영역에서 일정성분비를 유지하기 힘들다 . 정밀전기/ 광학장치에 있어 이런 변수는 치명적이라 할 수 있다. 결정의 조성과 질을 결정하는 방법으로 굴절율(n)을 측정하는 광학적 방법이 수행되어 왔다. 이 방법으로 성장결정의 광학적 균질성과 화학조성을 알아낼 수 있다. 여기서는 그런 특성분석에 사용 되는 기술을 설명하고 그 결과들을 제시해 보았다

• 한국축산식품학회지
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• 제36권2호
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• pp.145-151
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• 2016

The relationship between chemical compositions, meat quality traits, and palatability attributes in 10 primal cuts from Hanwoo steer carcasses were assessed. Sensory palatability attributes of Hanwoo beef were more closely related with fat content than to moisture or protein content. Among the chemical compositions, only fat had a significant correlation with juiciness (0.67, p<0.001), tenderness (0.32, p<0.05), and overall palatability (0.56, p<0.001). Oleic acid (%) was not significantly related with overall palatability (p>0.05). Overall palatability was negatively correlated with drip loss (−0.32, p<0.05), cooking loss (−0.36, p<0.05), and shear force (−0.54, p<0.01). The correlation between fat content and overall palatability was increased when higher fat cuts (Ansim, Dungsim, Chaekeut, Yangjee, and Kalbi) were analyzed, compared to lower fat cuts (Moksim, Abdari, Udun, Suldo, and Satae). Also, the correlation between shear force and overall palatability was decreased in lower fat cuts compared to higher fat cuts. Our results suggest that the palatability of Hanwoo beef can be improved by increasing fat content in muscles, as increased fat content leads to an increase in sensory tenderness, flavor, and juiciness.