• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.434-438
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• 2018

The sintering behavior of $BaFe_{12}O_{19}$ with the addition of one and three weight % of $CuWO_4$ as a liquid phase sintering aid is studied. Samples are sintered in the temperature range $900-1250^{\circ}C$ and the effect of $CuWO_4$ addition on density, microstructure, phase composition and magnetic properties is examined. Compared to $BaFe_{12}O_{19}$ with no sintering aid addition, addition of 1 wt % $CuWO_4$ retards densification. Addition of 3 wt % $CuWO_4$ promotes densification at lower sintering temperatures but retards densification at temperatures > $1050^{\circ}C$. Three wt % $CuWO_4$ addition induces the formation of $BaWO_4$ and $Ba_3WFe_2O_9$ secondary phases at temperatures ${\geq}1100^{\circ}C$. Addition of $CuWO_4$ causes a decrease in saturation magnetization, remanent magnetization and coercivity.

• Journal of Magnetics
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• 제14권4호
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• pp.150-154
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• 2009

The effect of Ga and, Nb addition on the kinetics and mechanism of the disproportionation of a Nd-Fe-B alloy were investigated by isothermal thermopiezic analysis (TPA) using $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ (x=0 and 0.3, y= 0 and 0.2) alloys. The addition of Ga and Nb retarded the disproportionation kinetics of the Nd-Fe-B alloy significantly, and increased the activation energy of the disproportionation reaction. The disproportionation kinetics of the $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ alloys measured under an initial hydrogen pressure of 0.02 MPa were fitted to a parabolic rate law. This suggested that during the disproportionation of $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ alloys with an initial hydrogen pressure of 0.02 MPa, a continuous disproportionation product is formed and the overall reaction rate is limited by the diffusion of hydrogen atoms (or ions).

• 한국식품영양과학회지
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• 제23권1호
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• pp.98-103
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• 1994

Some quality characteristics of tofu prepared with soyprotein isolate (SPI) were investigated to study the effects of various ratio of coagulants mixture and addition of oil, sucrose and dextrin. The tofu was prepared by addition of coagulants into the boiled SPI suspension and compression. The results showed that the mixed coagulants of CaCl $_2$-GDL(50 :50) and CaSO$_4$-GDL(25 :75) resulted the highest volume yield of 4.23g/g SPI among the various ratios of CaCl$_2$-CaSO$_4$, CaCl$_2$-GDL and CaSO$_4$-GDL. The water holding capacity(WHC) expressed as the area of water absorbed on filter paper was relatively high for those tofu coagulation with CaCl$_2$-GDL(75 : 25) and CaSO$_4$ -GDL(75 : 25). Addition of sucrose or oil-sucrose (1 : 1) decreased the yield wihle WHC was improved. Their addition also caused less hard and cohesive tofu which was coagulated by CaCl$_2$-GDL(75 : 25) and CaSO$_4$-GDL(75 : 25).

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1619-1620
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• 2013

• Advances in materials Research
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• 제5권2호
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• pp.93-105
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• 2016

KNN-based ceramics modified with small amounts of $Bi_4Zr_3O_{12}$ (BiZ) has been synthesized using high-throughput experimentation (HTE). The results from X-ray diffraction show that for samples with base composition $(K_{0.5}Na_{0.5})NbO_3$ (KNN), the phase present changes from orthorhombic to pseudo-cubic with more than 0.2 mol% BiZ addition; for samples with base composition $(K_{0.48}Na_{0.48}Li_{0.04})(Nb_{0.9}Ta_{0.1})O_3$ (KNNLT), the phase present changes from a mixture of orthorhombic and tetragonal symmetry to pseudo-cubic with more than 0.4 mol % while for samples with base composition $(K_{0.48}Na_{0.48}Li_{0.04})(Nb_{0.86}Ta_{0.1}Sb_{0.04})O_3$ (KNNLST), the phase present is tetragonal with <0.3 mol% BiZ addition and transforms to pseudo-cubic with more dopant addition. The microstructures of the samples show that addition of BiZ decreases the average grain size and increases the volume of pores at the grain boundaries. The values of dielectric constant for KNN and KNNLT compositions increase slightly with BiZ addition while that for KNNLST decreases gradually with BiZ addition. The dielectric loss values are between 0.02 and 0.04 for KNNLT and KNNLST compositions while they are ~ 0.05 for KNN samples. The resistivity values increases with BiZ addition and values in the range of $10^{10}{\Omega}cm$ and $10^{12}{\Omega}cm$ are obtained. The piezoelectric charge coefficient ($d{^*}_{33}$) is highest for KNNLST samples and decreases gradually from ~400 pm/V to ~100 pm/V with BiZ addition.

• Bulletin of the Korean Chemical Society
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• 제4권2호
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• pp.92-95
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• 1983

The addition products of glutathione to ${\beta}$ -nitrostyrene derivatives were synthesized. ${\beta}$ -Nitrostyrene (1a), p-methyl-${\beta}$-nitrostyrene (1b), 3,4,5-trimethoxy-${\beta}$-nitrostyrene (1c), o-, m- and p-chloro-${\beta}$-nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) undergo addition reactions with glutathione to form S-(2-nitro-1-phenylethyl)-L-glutathione (5a), S-[2-nitro-1-(p-methyl)phenylethyl]-L-glutatione (5b), S-[2-nitro-1-(3', 4', 5'-trimethoxy)phenylethyl]-L-glutathione (5c), S-[2-nitro-1-(o-chloro)phenylethyl]-L-glutathione (5e), S-[2-nitro-1-(m-choro)phenylethyl]-L-glutathione (5f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-glutathione (5g), S-[2-nitro-x-(o-methoxy)-phenylethyl]-L-glutathion e(5h), S-[2-nitro-x-(m-methoxy)phenylethyl]-L-glutathion e (5i), and S-[2-nitro-1-(p-methoxy)phenylethy])-L-glutathione (5j), respectively. The structure of adducts were identified by UV and IR-spectra, molecular weight measurement, and elemental analysis.

• 한국식품영양과학회지
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• 제32권1호
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• pp.62-66
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• 2003

양파의 소비를 촉진시키기 위한 일환으로 양파분말을 0, 2, 4, 6, 8, 10%로 첨가하여 스폰지 케이크를 제조하였을 때 제품의 물리화학적 변화를 고찰하였다 케이크 반죽의 비중과 점도는 양파 분말 첨가량이 증가할수록 높게 나타났다. 수분 함량은 양파분말 4% 첨가군이 가장 높은 값을 나타내었다. 케이크의 높이는 양파분말 2, 4% 첨가군이 대조군보다 높은 값을 나타내었다. 케이크 crust의 L, a, b값은 양파분말 첨가량이 증가할수록 감소하는 경향이었다. 케이크 crumb의 L값은 양파분말 첨가량이 증가할수록 다소 감소하는 경향이었다. a값은 대조군, 2 및 4% 첨 가군 사이에는 유의적인 차이가 없었으며, 6, 8, 10% 첨가군 사이에도 유의적인 차이는 없었다(p>0.05). b값은 대조군과 2% 첨가군 사이에는 유의적인 차이가 없었으며, 4, 5, 8, 10% 첨가군 사이에도 유의적인 차이는 없었다 (p>0.05). 비체적의 경우 양파분말 4% 첨가군이 4.17 cc/g로 가장 높은 값을 나타내었다. 경도(hardness), 탄력성 (spring-mess), 응집성 (cohesiveness), 검성(gumminess), 씹힘성(chew mess), 복원성(resilience)은 대조군에 비해 양파분말 첨가군이 높은 값을 나타내었다. 관능검사에서는 종합적인 기호도 (overall acceptability)에서 2, 4% 첨가군이 우수하였다.

• 한국세라믹학회지
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• 제34권3호
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• pp.281-288
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• 1997

유전율이 높고 온도안정성이 우수하다고 알려져 있는 40Pb(Mg1/3Nb2/3)O3-30PbTiO3-30Pb(Mg1/2W1/2)O3계 세라믹스에 소결온도를 낮추기 위하여 저온에서 액상을 형성하는 91PbO-9WO3를 과잉첨가하여 소결성, 미세구조 및 유전성의 변화에 대하여 조사하였다. 91PbO-9WO3의 첨가량이 증가함에 따라 소결온도가 저하하였으며 6 mol%첨가시는 875$^{\circ}C$에서 소결이 가능하였다. 유전율은 기본조성에서 16,400이었고, 첨가제가 1 mol% 과잉첨가된 경우 18,500으로 최대값을 나타냈으며 이후 첨가량이 증가함에 따라 감소하였다. 첨가제의 첨가량이 2~4mol%인 시편의 온도에 따른 유전율 변화곡선에서 double peak maxima가 나타났으나, 첨가량이 5 mol% 이상인 시편에서는 입계에 텅스텐을 많이 포함하고 있는 결정상이 생성되었고 double peak maxima는 나타나지 않았다.

• 아시안잔디학회지
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• 제8권3호
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• pp.137-147
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• 1994

We have established a high-frequency plant regeneration system via organogenesis from mature seed of Korean lawngrass(Zoysia japonica Steud.). The effects of 2,4-dichiorophenoxy acetic acid (2,4-D), 6-furfuryl amino purine (kinetin), $\alpha$-naphthaiene acetic acid (NAA), N6-benzyl amino pu-rine (BAP), and casein hydrolysate (CR) on cailus induction and multiple shoot formation on ex-posure to light were evaluated. Callus produced on the Murashige and Skoog (MS) medium containing 2,4-D and kinetin had high organogenesis potency. A single addition of 1.0 mg $L-^1$ 2,4-D significantly induced callus. Also, 1.0 mg L-$^1$ 2,4-D, with the addition of 0.1 mg $L-^1$ kinetin highly enlianced callus induction. The trend of cailus induction was also found on mediurn containing 0.1 mg $L-^1$ BAP with 1.0 mg $L-^1$2,4-D, and 1 g $L-^1$ CR with the addition of 1.0 mg $L-^1$ 2,4-D. However, NAA was no effective on callus formation. The growth of root was significantly high in the presence of 0.1 mg $L-^1$ kinetin compared to other concentrations. Over 2 mg $L-^1$ kinetin highly lengthened roots. Fresh weight of plantlet was highest on medium containing 0.1 mg $L-^1$ 2,4-D. Also, on medium containing 0.1 mg $L-^1$ BAP, fresh weight of piantlet was highly enhanced. BAP was significantly effective on multiple shoot formation, particularly when 2.0 mg $L-^1$ was added with 0.1 mg $L-^1$ 2,4-D. Callus induction and multiple shoot formation were achieved on MS basal medium containing 1.0 g $L-^1$ CH.

• 한국주조공학회지
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• 제37권5호
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• pp.148-156
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• 2017

The effects of minor additives on the casting properties of AC4A aluminum alloys were investigated. Measurements of the cooling curve and microstructure observations were conducted to analyze the effects of Ti-B and Sr minor elements during the solidification process. A fine grain size and an increase in the crystallization temperature for the ${\alpha}-Al$ solution were evident after the addition of 0.1wt% Al-5%Ti-1%B additive. The modification effect of the eutectic $Mg_2Si$ phase with the addition of 0.05% Al-10%Sr additive was prominent. A fine eutectic $Mg_2Si$ phase and a decrease in the growth temperature of the eutectic $Mg_2Si$ phase were evident. Fluidity, shrinkage and solidification-cracking tests were conducted to evaluate the castability of the alloy. The combined addition of Al-5%Ti-1%B and Al-10%Sr additives showed the maximum filling length owing to the effect of the fine ${\alpha}-Al$ grains. The macro-shrinkage ratio increased, while the micro-shrinkage ratio decreased with the combined addition of Al-5%Ti-1%B and Al-10%Sr additives. The macro-shrinkage ratio was nearly identical, while the micro-shrinkage ratio increased with the addition of the Al-10%Sr additive. The tendency of the occurrence of solidification cracking decreased owing to the effect of the fine ${\alpha}-Al$ grains and the modification of the $Mg_2Si$ phase with the combined addition of Al-5%Ti-1%B and Al-10%Sr additives.