• 한국식품과학회지
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• 제27권3호
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• pp.329-335
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• 1995

전지대두분을 주원료로 하여 콩묵을 제조할 때 가수량, Ca염의 양이 콩묵의 텍스쳐 특성에 미치는 영향을 조사하였다. 콩묵은 $100^{\circ}C$의 물에 전지대두분(300 mesh)을 첨가해서 분산시킨 뒤 sodium alginate를 혼합하고 Ca gluconate나 $CaSO_4$를 첨가하여 교반한 후 $4^{\circ}C$로 냉각시켜 제조하였다. 교반시간이 5분에서 30분까지 증가함에 따라 콩묵의 견고성, 부착성, 응집성은 증가하는 경향을 보였으며 텍스쳐 특성과 관능적 특성의 결과로부터 교반시간은 20분으로 선정하였다. 대두분의 수분 첨가량이 8배에서 12배로 증가함에 따라서 견고성, 부착성은 감소하는 경향을 보였지만 Ca염 모두 텍스쳐가 우수한 균일성을 나타났기 때문에 전지대두분의 10배 수분 첨가가 선정되었다. 10배의 수분을 첨가할 때 Ca염 중에서 견고성은 $CaSO_4$가 425g으로 가장 높았으며 그 다음이 Ca $gluconate-CaSO_4$(413g), Ca gluconate(227g)순으로 나타났다. Ca염의 양을 $0.075g{\sim}0.175g/g$ WSF 범위로 하여 텍스쳐 특성과 관능적 특성을 종합할 때 전지대두분 1g당 0.125g의 Ca gluconate나 $CaSO_4$ 첨가가 선정되었다. Ca gluconate와 $CaSO_4$의 혼합 Ca염을 사용할 때는 50 : 50, 25 : 75, 0 : 100의 3가지 비율에서 견고성이 적당하였고 균일성이 우수하게 나타났다.

• 열처리공학회지
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• 제27권4호
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• pp.185-190
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• 2014

The influences of small amount of Sn addition on microstructure and creep resistance of AZ91-0.4%Ca alloy have been investigated. The microstructure of the AZ91-0.4%Ca alloy was characterized by ${\alpha}$-(Mg) dendrite cells surrounded by eutectic ${\beta}(Mg_{17}Al_{12})$ and $Al_2Ca$ phases. The 0.5%Sn addition resulted in the formation of rod-shaped CaMgSn particles with the extinction of $Al_2Ca$. The Sn-containing alloy exhibited better creep resistance below $175^{\circ}C$, but the tendency was reversed above $200^{\circ}C$. The reason was discussed in relation to the change in thermal stability of ${\beta}$ phase in response to the Sn addition.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.349-352
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• 2005

In this work, effects of limestone powder on hydration of $C_3A-CaSO_4\cdot2H_2O$ system was discussed based on the XRD Quantitative analysis, and the possibility of Delayed Ettringite Formation was also discussed. The early hydration of $C_{3}A$ was delayed by addition of $CaCO_{3}$ powder. The delay effect was enhanced by increasing of $CaCO_{3}$ content and finer powder of $CaCO_{3}$ addition. After consumption of $CaSO_4\cdot2H_2O$, the reaction of $CaCO_{3}$ is started. Delayed Ettringite Formation would take place because monosulfoaluminate is not stable in presence of $CaCO_{3}$. In order to prevent the delayed ettringite formation in $C_3A-CaSO_4\cdot2H_2O-CaCo_3$ system, the reduction of monosulfoaluminate formation is important. Therefore, by increasing the amount of $CaCO_{3}$ addition and finer $CaCO_{3}$ powder addition, the delayed ettringite formation can be prevented.

• 한국산학기술학회논문지
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• 제3권1호
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• pp.32-37
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• 2002

Ca/sup 2+/ 이온은 식물조직의 경도 유지에 중요한 역할을 하는 것으로 알려져 있다. 따라서, Ca/sup 2+/의 첨가가 깍두기의 가식기간 연장에 미치는 영향, 적정 농도 및 효율적 첨가방법을 알아보고자 하였다. CaCl₂의 첨가에 의해 깍두기의 숙성기간 중 pH의 감소, 산도의 증가 및 기계적 경도의 감소 속도가 억제되어 가식기간이 연장되었다. 또한, Ca/sup 2+/ 첨가에 의해 관능적 특성 중 아삭함, 신맛 및 총체적인 기호도가 개선되었다. CaCl₂의 첨가방법과 농도는, 무를 절이는 염수에 0.1%의 CaCl₂를 첨가하고 절임과정이 끝나면 수세한 후 다시 양념과 함께 0.05%의 CaCl₂를 첨가하여 깍두기를 제조하는 것이 가장 효과적인 것으로 나타났다.

• 한국세라믹학회지
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• 제31권12호
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• pp.1417-1422
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• 1994

Effect of MgO, CaSO4, and CaF2 addition on the formation of clinker minerals in portland cement have been investigated by measuring the amounts of free-CaO and C3S in the fired specimens and analyzing the Mg and S concentration in C3S and C2S. It was found that CaSO4 inhibited C3S formation but MgO addition offset this effect of CaSO4. MgO addition also enhanced the mineralizing effect of CaSO4+CaF2, resulting in the acceleration of C3S formation. It was suggested that Mg might inhibit the formation of sulphate compounds rim around C2S and thus C2S+CaOlongrightarrowC3S reaction was facilitated.

• Corrosion Science and Technology
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• 제4권4호
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• pp.121-129
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• 2005

Basic design concept of the future steel structure requires environmental compatibility and maintenance free capability to minimize economic burdens. Recent trends in alloy design for advanced weathering steel include addition of various alloying elements which can enhance formation of stable and protective rust layer even in polluted urban and/or high $Cl^{-}$ environment. The effects of Ca, Ni, W, and Mo addition on the corrosion property of Ca-modified weathering steel were evaluated through a series of electrochemical tests (pH measurement and electrochemical impedance spectroscopy: EIS) and structural analysis on rust layer formed on the steel surface. Ca-containing inclusions of Ca-Al-Mn-O-S compound are formed if the amount of Ca addition is over 25 ppm. Steels with higher Ca content results in higher pH value for condensed water film formed on the steel surface, however, addition of Ni, W, and Mo does not affect pH value of the thin water film. The steels containing a high amount of Ca, Ni, W and Mo showed a dense and compact rust layer with enhanced amount of ${\alpha}-FeOOH$. Addition of Ni, W and Mo in Ca-modified weathering steel shows anion-selectivity and contributes to lower the permeability of $Cl^{-}$ ions. Effect of each alloying element on the formation of protective rust layer will be discussed in detail with respect to corrosion resistance.

• 한국주조공학회지
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• 제23권5호
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• pp.251-256
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• 2003

Effects of Ca addition on grain refinement, microstructure and mechanical properties of AZ31 Mg alloy were investigated. Due to Ca addition to Mg alloy (AZ31), the microstructure was refined, the quantity of $Mg_{17}Al_{12}$phase was reduced, and new $Al_2Ca$ phase was formed. The tensile property of AZ31 was increased with the minor addition of Ca, but was decreased rapidly over 0.2 wt.% of Ca content. The $Al_2Ca$ phase was considered to be detrimental to the mechanical property of AZ31 Mg alloy.

• 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).

• 한국재료학회지
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• 제25권6호
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• pp.269-273
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• 2015

The effect of adding Ca on the microstructural and mechanical properties of as-cast Mg-11Li-3Zn-1Sn(wt%) alloys were investigated. Mg-11Li-3Zn-1Sn-0.4Mn with different Ca additions (0.4, 0.8, 1.2 wt%) were cast under an $SF_6$ and $Co_2$ atmosphere at $720^{\circ}C$. The cast billets were homogenized at $400^{\circ}C$ for 12h and extruded at $200^{\circ}C$. The microstructural and mechanical properties were analyzed by OM, XRD, SEM, and tensile tests. The addition of Ca to the Mg-11Li-3Zn-1Sn-0.4Mn alloy resulted in the formation of $Ca_2Mg_6Zn_3$, MgSnCa intermetallic compound. By increasing Ca addition, the volume fraction and size of $Ca_2Mg_6Zn_3$ with needle shape were increased. This $Ca_2Mg_6Zn_3$ intermetallic compound was elongated to the extrusion direction and refined to fine particles due to severe deformation during hot extrusion. The elongation of the 0.8 wt% Ca containing alloy improved remarkably without reduction strength due to the formation of fine grain and $Ca_2Mg_6Zn_3$ intermetallic compounds by Ca addition. It is probable that fine and homogeneous $Ca_2Mg_6Zn_3$ intermetallic compounds played a significant role in the increase of mechanical properties.

• 열처리공학회지
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• 제26권3호
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• pp.113-119
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• 2013

Grain growth behaviors of hot-rolled AZ31 (Mg-3%Al-1%Zn) and AZ31-0.3%CaO alloys at elevated temperatures have been investigated in order to clarify the effect of CaO addition on grain stability of Mg-Al-based wrought alloy. The grain size of CaO-free alloy increased steeply from 673 K with an increase in annealing temperature from 573 to 773 K, whereas the grains of CaO-containing alloy were relatively stable up to 723 K. The activation energies for grain growth ($E_g$) were 12.2 and 18.3 kJ/mole between 573 and 673 K and 119.2 and 126.9 kJ/mole between 673 and 773 K in the AZ31 and AZ31-0.3%CaO alloys, respectively. This result indicates that grains in the CaO-added alloy possess higher thermal stability than CaO-free alloy. SEM observations on the annealed alloy samples revealed that higher grain stability resulting from CaO addition would be associated with the suppression of grain growth by Ca-related precipitate particles distributed in the microstructure.