• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.269-274
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• 2010

The solubility and the physicochemical property (refractive index) in the NaCl-$CaCl_2$-$H_2O$ and KCl-$CaCl_2$-$H_2O$ systems were determined at $50^{\circ}C$ and the phase diagrams and the diagrams of physicochemical property vs composition were plotted. One invariant point, two univariant curves, and two crystallization zones, corresponding to sodium Chloride (or potassium chloride), dihydrate ($CaCl_2{\cdot}2H_2O$) showed up in the phase diagrams of the ternary systems. The mixing parameters ${\theta}_{M,Ca}$ and ${\Psi}_{M,Ca,Cl}$ (M = Na or K) and equilibrium constant $K_{sp}$ were evaluated in NaCl-$CaCl_2-H_2O$ and KCl-$CaCl_2-H_2O$ systems by least-squares optimization procedure, in which the single-salt Pitzer parameters of NaCl, KCl and $CaCl_2$ ${\beta}^{(0)}$, ${\beta}^{(1)}$, ${\beta}^{(2)}$ and $C^{\Phi}$ were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.277-281
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• 2003

Effects of $CaF_2$ addition as a filler on the high frequency dielectric properties and sintering of CaO-$Al_2O_3-SiO_2-B_2O_3$(CASB) and ZnO-MgO-$B_2O_3-SiO_2$(ZMBS) glass composites were investigated. The optimal glass composition in the CASB system was 33.0CaO-$17.0Al_2O_3-35.0SiO_2-15.0B_O_3$(in wt%). The corresponding dielectric properties were k=8.1 and $Q{\times}fo$=1,200GHz. The sintering temperature was $800{\mu}m$. In case of 2MBS system, 25.0ZnO-25.0MgO-20.0$B_2O_3-30.0SiO_2$(in wt%) glass showed k=6.8 and $Q{\times}fo$=5,200GHz when it was sintered at $750^{\circ}C$. The maximum amount of $CaF_2$ in the CASB and 2MBS glass system without any detrimental effect on the sintering was 25.0 v/o and 15.0 v/o, respectively. The addition of $CaF_2$ in the glass systems improved the high frequency dielectric properties. In case of CASB+$CaF_2$ composite, k was 7.1 and $Q{\times}fo$ was 2,300GHz. And in case of 2MBS+$CaF_2$ composite, k was 5.9 and $Q{\times}fo$ was 8,100GHz. $CaF_2$ addition also reduced sintering temperature. Effects of $CaF_2$ on the dielectric and sintering properties was analyzed in terms of viscosity and crystallization behavior changes due to the interaction between $CaF_2$ and the glass systems.

• Journal of the Korean Ceramic Society
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• v.29 no.9
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• pp.729-738
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• 1992

The glass formation and structural change with the glass compositions were investigated in the CaO-P2O5-SiO2 system with less than 40 wt% of P2O5. The glass formation range was determined by XRD, SEM and EDS techniques for water quenched specimens. The structural analyses were made for binary CaO-SiO2 glasses and ternary CaO-P2O5-SiO2 glasses by using FT-IR and Raman spectroscopy. The glass formation was affected by CaO/SiO2 mole ratio, P2O5 content and primary crystalline phase. The stable glass formation range was found when the transformed CaO/SiO2 mole ratio (new factor derived from structural changes) was in the range of 0.72~1.15 with less than 10 mol% of P2O5. The structural analyses of CaO-SiO2 glasses indicated that as the CaO/SiO2 ratio was increased, the nonbridging oxygens in the structural unit of the glasses were increased. With addition of P2O5 to CaO-SiO2 glasses, the P2O5 enhanced the polymerization of [SiO4] tetrahedra unit in CaO-SiO2 glasses, which contained a large portion of nonbridging oxygen. The phosphate eliminated nonbridging oxygens from silicate species, forcing polymerization of silicate structures and produced in [PO4] monomer in glasses. When added P2O5 was kept constant, the structural change with various CaO/SiO2 ratio was very similar to that of CaO-SiO2 glasses.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.202-208
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• 2013

This study was conducted to investigate the effect of delayed controlled atmosphere (CA) storage on fruit quality and the incidence of storage disorders during CA storage of 'Fuji' apples (Malus x domestica Borkh.). In the first year of experiment, 'Fuji' apples showed 40% of watercore disorder at the commercial harvest time (Oct. 22). Twenty days delayed CA storage caused to develop the incidence of flesh browning while 30 days delayed CA storage did not. In the second year of experiment, watercore was increased with delaying harvest time. As the estabilishment of delayed CA storage was delayed, the incidence of flesh browning increased at 10 to 30 days delayed CA storage but 40 days delayed CA storage did not have any flesh browning incidence. Respiration rate increased with extending the storage duration. Delayed CA storage reduced respiration rate but was not different compared to the rapid CA. Ethylene production rate was lower in delayed CA storage than in cold storage but higher in delayed CA storage, compared to rapid CA storage. Titratable acidity was lower in delayed CA storage as CA storage progressed. Firmness was not different between rapid CA storage and delayed CA storage after 8 months of CA storage. Therefore, the results indicate that delayed CA storage should be a promising approach to reduce the risk development of flesh browning and watercore during CA storage of 'Fuji' apples.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.33-39
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• 2002

This study was conducted to investigate the effect of $Ca^{2+}$ concentration in fusion medium on the fusion, nuclear morphology and the development of bovine somatic cell nuclear transfer embryos. Bovine skin cells were transferred into an enucleated oocyte and fused with cytoplasm in the fusion medium containing with 0.05 to 1.0 mM Cacl$_2$. Nuclear transfer embryos were activated with a combination of A23187 and cycloheximide. Nuclear transfer embryos were fixed at 3 h after fusion or cultured for 7 ~8 days. Fusion rate was significantly (P＜0.01) increased by increasing the $Ca^{2+}$ concentrations in the fusion medium from 0.05 mM (56.6%) to 0.5 mM (50.1%) and 1.0 mM (84.3%). More than 80% of reconstituted embryos underwent premature chromosome condensation (PCC) with 0.05, 0.1 mM CaCl$_2$, whereas 54.5% and 59.3% of embryos formed pronucleus (PN) directly without PCC in the 0.5 and 1.0 mM CaCl$_2$, groups. Blastocyst formation rates were significantly (P＜0.05) different between 0.1 mM and 1.0 mM CaCl$_2$groups. From the present result, it is suggested that the elevated $Ca^{2+}$ concentrations in fusion medium can enhance the fusion and blastocyst formation rates of bovine nuclear transfer embryos.bryos.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.76-82
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• 1993

Two crystal structures of fully dehydrated Ca(II) and Tl(I) exchanged zeolite A, $Ca_{5.6}Tl_{0.8}-A (a = 12.242(2){\AA})\;and\;Ca_{1.4}Tl_{9.2}-A (a = 12.191(1){\AA})$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Pm3m at 21(1)$^{\circ}C$. All crystals were ion exchanged in flowing streams of mixed $Ca(NO_3)_2\;and\;TINO_3$ aqueous solution with total concentration of 0.05M. All crystals were dehydrated at 360$^{\circ}C$ under $2{\times}10^{-6}\;torr$ for two days. The structures of the dehydrated $Ca_{5.6}Tl_{0.8}-A$ and $Ca_{1.4}Tl_{9.2}-A$ were refined to the final error indicies, $R_1$ = 0.072 and $R_2$ = 0.076 with 179 reflections for I > 3$\sigma$(I), and $R_1$ = 0.048 and $R_2$ = 0.043 with 226 reflections for I > 3$\sigma$(I), respectively. In each structure, Ca(II) ions are located on threefold axes associated with three 6-ring oxygens. $Ca^{2+}$ ions prefer to 6-ring sites and $Tl^+$ ions prefer to 8-ring sites when total number of exchanged cations per unit cell is more than 8.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.2
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• pp.101-107
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• 2002

In the present study, the postnatal developmental changes in the expressional levels of cardiac sarcoplasmic reticulum (SR) $Ca^{2+}$ regulatory proteins, i.e. $Ca^{2+}-ATPase,$ phospholamban, and $Ca^{2+}$ release channel, were investigated. Both SR $Ca^{2+}-ATPase$ and phospholamban mRNA levels were about 35% of adult levels at birth and gradually increased to adult levels. Protein levels of both SR $Ca^{2+}-ATPase$ and phospholamban, which were measured by quantitative immunoblotting, were closely correlated with the mRNA levels. The initial rates of $Ca^{2+}$ uptake at birth were about 40% of adult rates and also increased gradually during the myocardial development. Consequently, the relative phospholamban/$Ca^{2+}-ATPase$ ratio was 1 in developmental hearts. $Ca^{2+}$ release channel (ryanodine receptor) mRNA was about $50{\sim}60%$ at birth and increased gradually to adult level throughout the postnatal rat heart development. $^3[H]ryanodine$ binding increased gradually during postnatal myocardial development, which was closely correlated with ryanodine mRNA expression levels during the development except the ryanodine mRNA level at birth. These findings indicate that cardiac SR $Ca^{2+}-ATPase,$ phospholamban, and $Ca^{2+}$ release channel are expressed coordinately, which may be necessary for intracellular $Ca^{2+}$ regulation during the rat heart development.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.195-195
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• 2008

CAS계 유리에 $CaCO_3-Al_2O_3$ 혼합물 및 화합물을 10, 30 wt% 첨가하여 저온 소걸 및 마이크로파 유전 특성을 고찰하였다. CAS계 유리의 연화온도는 $841^{\circ}C$ 이며, CAS계 유리에 $CaCO_3$ 와 30 wt%의 $CaCO_3-Al_2O_3$ 혼합물을 melting되며, 10 wt%의 $CaCO_3$, $Al_2O_3$, $1CaCO_3-1Al_2O_3$ 혼합물 및 $CaAl_2O_4$ 화합물를 10 wt% 첨가하였을 때 $900^{\circ}C$ 이하에서 소걸이 가능하였다. 복합체의 XRD 상 분석 결과, CaCO3를 첨가하였을 때에는 모든 조성이 비정질을 나타내었고, $Al_2O_3$와 $1CaCO_3-1Al_2O_3$ 혼합물은 $Al_2O_3$ 결정상이 생성되었고, $CaAl_2O_4$ 화합물은 $CaAl_2Si_2O_8$의 hexagonal와 anorthite 결정상이 생성되었다. 따라서 CAS-10 (A, C-A, CA) 복합체는 $900^{\circ}C$에서 각각 유전율 ($\varepsilon_r$) 6.4, 6.9, 5.15 와 품질계수 ($Q^*f$) 2,400, 1,500, 3,000의 마이크로파 유전 특성을 나타내어 LTCC 기판 재료로 사용이 가능하며, 특히 $CaAl_2O_4$ 화합물을 사용하였을 때 가장 우수한 유전 특성을 나타내는 것을 확인하였다.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.402-409
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• 2000

To investigate the textural and physical characteristics of WSF(whole soybean flour) tofu affected by coagulant and its concentration, $CaCl_2$, $CaSO_4$, $GDL(glucono-{\delta}\;lactone)$, $MgCl_2$, and some mixed coagulants were used in this study. Yields of WSF tofu coagulated with $CaSO_4$ and GDL were ranged 4.3-4.5(g/g WSF), but common tofu was 2.2-3.0(g/g soybean). As the water addition ratio increased, L and a value were increased while heating time increased, b value increased. L value of WSF tofu was lower and b value was higher than conventional tofu and 4 commercial tofus. Kinds of coagulant and its concentration significantly affected to textural properties of WSF tofu. As the concentration of coagulant increase, the hardness increased in most all coagulants. WSF tofu coagulated with $CaSO_4$ and GDL recorded low hardness and adhesiveness, and high springiness among the used coagulants at the same concentration. As the hardness increased, the gumminess and chewiness increased in most all coagulants. As coagulation temperature and molding pressure increase, hardness also increased. WSF tofu coagulated with 0.3% $CaSO_4+GDL$ was the most similar in the textural properties with conventional tofu and 4 commercial tofus. WSF tofu coagulated with 0.3% of $CaSO_4+GDL$ at $85^{\circ}C$, 10 times water addition, 5min. heating and $25.0g/cm^2$ molding pressure recorded the highest score in the sensory evaluation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.2
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• pp.63-70
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• 1992

$AI_2O_3/Ca-TZP$ composites was prepared by using the starting powder of alumina and Ca-TZP synthesized by hydrothermal reaction and investigated to its characteristics. The ratio of tetragonal zirconia to monoclinic within $AI_2O_3$ matrix was decreased with an addition of Ca-TZP content, but the absolute amount of tetragonal phase in composites was increased with an addition of Ca-TZP content. The value of fracture toughness in $AI_2O_3/Ca-TZP$composites was proportional to the amounts of transformed tetragonal phase which formed by crack propagation in fracture, and therefore, it was gradually increased with an addition of Ca- TZP content.