• Title/Summary/Keyword: $^{45}Ca\

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Garnet-Orthopyroxene Geothermometer and Geological Applications (석류석-사방휘석 지질온도계와 지질학적 응용)

  • Lee, Han Yeang
    • Economic and Environmental Geology
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    • v.21 no.1
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    • pp.29-44
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    • 1988
  • Equilibrium relations between garnet and orthopyroxene have been investigated by reversal experiments in the range of 20-45Kb and $975-1400^{\circ}C$ in the $FeO-MgO-Al_2O_3-SiO_2$(FMAS) system. A mixture of PbO with about 55 mol per cent $PbF_2$ was used as a flux and proved very effective. The Fe-Mg exchange reaction seems to have little or no compositional dependence at these conditions. Combination of the experimental results with the garnet mixing model of Ganguly and Saxena(1984) yields the following geothermometric expression for the common natural assemblages that can be represented essentially within the system $FeO-MgO-CaO-MnO-Al_2O_3-SiO_2$. $$T^{\circ}C=(1971+11.91P(Kb)+1510(X_{Ca}+X_{Mn})^{Gt}/(lnK_D+0.96)-273$$.

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Sticking Characteristics in BiSrCaCuO Thin Film Fabricated by Layer-by-Layer Sputtering Method (순차 스퍼터법으로 제작한 BiSrCaCuO 박막의 부착 특성)

  • Cheon, Min-Woo;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.45-48
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    • 2003
  • BiSrCaCuO thin films were fabricated by atomic layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to $SrBi_2O_4$ by in-situ anneal.

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A Study on the Factors Affecting Bone Mineral Density in Adult Women - Based on the Mothers of Elementary School Students- (일부 초등학생의 어머니를 대상으로 한 성인 여성의 골밀도에 영향을 미치는 요인에 관한 연구)

  • 김기랑
    • Journal of Nutrition and Health
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    • v.33 no.3
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    • pp.241-249
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    • 2000
  • The bone mineral density(vertebrae Ll-4, femoral neck, Ward's triangle and trochanter) of 160 healthy adult women aged 29-45 was measured and general characteristics, anthropomentric measurements, and dietary intake were also studied to determine the main factors affecting the bone mineral density(BMD) of adult women. The nutrient intake of the subjects was adequate to RDA level except energy, Ca, Fe, and vit A. The BMD of vertebrae L24 showed significant positive association with nutrient intake such as animal protein, P, Ca(animal) and Fe(animal). The BMD of the femoral neck correlated significantly with anthropometric measurements such as height, weight, waist circumference, hip circumference, body fat and body mass index. The BMD of both sites(vertebrae L24 and femoral neck) were significantly related to vertebrae L24 was daily Ca intake and that of femoral neck was daily energy expenditure. In conclusion, adequate nutrient intake, especially protein, P, Ca and Fe as well as increases in physical activity were suggested to prevent the loss of bone mineral density in adult women.

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A Study on the Fixed amount of CO2 and the estimation of production on CaCO3 of Waste Concrete Powder using the Ca(OH)2 (Ca(OH)2를 이용한 폐콘크리트 미분말의 CO2 고정량 및 CaCO3 생성량 추정에 관한 연구)

  • Ahn, Hee-Sung;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.117-118
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    • 2011
  • South Korea is a ninth greenhouse gas emission nation in the world(2007) and is certainly to perform a duty to conduct reduction role by the Kyoto Protocol in 2013. waste concrete produced in the country is 45 million tons per year and these two issues are being came to the fore as major problems of society. However, if it utilizes wet carbonation system carbon using carbon dioxide and waste concrete as raw material it can expect effect of environmental protection and resource recycling. Furthermore, it can exploit another industry production.

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Dielectric Properties of $(Ba,Sr,Ca)TiO_{3}$ Ceramics with Additon of Dopant (불순물 첨가에 따른 $(Ba,Sr,Ca)TiO_{3}$ 세라믹의 유전특성)

  • Lee, Sung-Gap;Lee, Young-Hie;Lim, Sung-Soo;Park, In-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.42-45
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    • 2001
  • $(Ba_{0.6}Sr_{0.4}Ca_{x})TiO_{3}+yZrO_{2}$ wt% (x=0.10, 0.15, 0.20, y=0.5~3.0) specimens were fabricated by the mixed-oxide method and then the structural and dielectric properties as a function of the composition ratio and $ZrO_2$ contents were studied. All BSCT specimens showed dense and homogeneous structure without the presence of the seconds phase. The Curie temperature and the dielectric constant at room temperature decreased with increasing the Ca/Ba composition ratio and $ZrO_2$ content. The BSCT(50/40/10) specimens showed the excellent tunability property. And the tunability were increased with increasing the contents of $ZrO_2$.

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Dielectric Properties of (Ba,Sr,Ca)$TiO_3$ Ceramics with Addition of Dopant (불순물 첨가에 따른 (Ba,Sr,Ca)$TiO_3$ 세라믹의 유전특성)

  • 이성갑;이영희;임성수;박인길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.42-45
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    • 2001
  • (Ba$_{0.6-x}$Sr$_{0.4}$Ca$_{x}$)TiO$_3$+yZrO$_2$wt% (x=1.10, 0.15, 0.20, y=0.5~3.0) specimens were fabricated by the mixed and ZrO$_2$ contents were studied. All BSCT specimens contents were studied. All BSCT specimens showed dense and homogeneous structure without the presence of the seconds phase. The Curie temperature and the dielectric constant at room temperature decreased with increasing the Ca/Ba composition ratio and ZrO$_2$ content. The BSCT(50/40/10) specimens showed the excellent tunability property. And the tunability were increased with increasing the contents of ZrO$_2$./TEX>.

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Activation and In Vitro Development of Porcine Oocytes Treated with Ethanol, $Ca^{2+}-Ionophore$ and Strontium (Ethanol, $Ca^{2+}-Ionophore$ 및 Strontium이 돼지 난자의 활성화와 체외 발달에 미치는 영향)

  • Ahn, H.J.;Lee, J.W.;Kang, M.J.;Moon, S.J.
    • Journal of Embryo Transfer
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    • v.22 no.1
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    • pp.75-80
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    • 2007
  • The objective of this study was to examine the optimal concentration and the exposure time of ethanol, Ca-ionophore, and strontium to achieve massive recipient oocytes in porcine. The cleavage (51.4% vs. $21.3{\sim}44.3%$) and embryo development rates (45% vs. $13.3{\sim}29.9%$) were significantly higher (p.0.05) in oocytes treated with 10% ethanol for 10 min than other treatments. The oocytes treated with 25mM Ca-ionophore for a minimum of 2min and 20mM strontium for a minimum of 6h showed significantly higher cleavage and embryo development rates than those of other treatments (P<0.05). Cleavage rate with duplicated ethanol treatment was significantly lower than those with ethanol alone (P<0.05). The cleavage rate and embryo development rates were significantly lower in duplicated strontium treatment than those in both alone and combination (P<0.05). But the cleavage and embryo development rates in treatment with Ca-ionophore were significantly higher in combined treatment (Ca-ionophore and cycloheximide) than those in single or duplicated treatment (P<0.05). These results might induce establishment of the optimal concentration and the exposure time on activation media to build up activation condition of porcine oocytes.

Effect of Different Pre-treatments on the Physicochemical and Antioxidant Activities of Cold-Vacuum Dried Peaches (전처리조건에 따른 냉풍감압건조 복숭아의 이화학적 및 항산화 활성)

  • Kwon, Gi-Man;Kim, Jae-Won;Youn, KwangSup
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.466-472
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    • 2013
  • This study was performed to determine the effects of the pretreatment and cold-vacuum drying methods on the physicochemical properties and antioxidant activities of dried peaches. Moisture content was significantly lower with 0.3% NaCl treatment with cold-vacuum drying. The pH, brix and acid ratio (SS/TA) were the lowest with 1.0% soluble Ca treatment, while soluble solid and SS/TA were significantly higher with 0.1% vitamin C treatment compared to those with other treatments. The ${\delta}E$ and browning degree was lower in the pretreated sample compared to the untreated sample. Cutting strength of dried peaches was highest in the pretreated samples, and it was the highest with 1.0% soluble Ca treatment. Total sugar content with 0.1% vitamin C and 1.0% soluble Ca treatment was significantly higher than that with 0.3% NaCl treatment. The free sugar content was lower with 0.3% NaCl treatment but it was higher with 0.1% vitamin C and 1.0% soluble Ca treatment. The sensory evaluation result was highest with 0.1% vitamin C treatment. Phenolic compounds and antioxidant ability were the highest with the 0.1% vitamin C and 0.1% soluble Ca treatment; all the dried peaches showed relatively high antioxidant activities. These results suggest that pretreatment can affect the quality of dried peaches, showing that cold-vacuum drying can be applied for the production of high quality dried peach products.

Effects of zinc oxide and calcium-doped zinc oxide nanocrystals on cytotoxicity and reactive oxygen species production in different cell culture models

  • Gabriela Leite de Souza ;Camilla Christian Gomes Moura ;Anielle Christine Almeida Silva ;Juliane Zacour Marinho;Thaynara Rodrigues Silva ;Noelio Oliveira Dantas;Jessica Fernanda Sena Bonvicini ;Ana Paula Turrioni
    • Restorative Dentistry and Endodontics
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    • v.45 no.4
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    • pp.54.1-54.16
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    • 2020
  • Objectives: This study aimed to synthesize nanocrystals (NCs) of zinc oxide (ZnO) and calcium ion (Ca2+)-doped ZnO with different percentages of calcium oxide (CaO), to evaluate cytotoxicity and to assess the effects of the most promising NCs on cytotoxicity depending on lipopolysaccharide (LPS) stimulation. Materials and Methods: Nanomaterials were synthesized (ZnO and ZnO:xCa, x = 0.7; 1.0; 5.0; 9.0) and characterized using X-ray diffractometry, scanning electron microscopy, and methylene blue degradation. SAOS-2 and RAW 264.7 were treated with NCs, and evaluated for viability using the MTT assay. NCs with lower cytotoxicity were maintained in contact with LPS-stimulated (+LPS) and nonstimulated (-LPS) human dental pulp cells (hDPCs). Cell viability, nitric oxide (NO), and reactive oxygen species (ROS) production were evaluated. Cells kept in culture medium or LPS served as negative and positive controls, respectively. One-way analysis of variance and the Dunnett test (α = 0.05) were used for statistical testing. Results: ZnO:0.7Ca and ZnO:1.0Ca at 10 ㎍/mL were not cytotoxic to SAOS-2 and RAW 264.7. +LPS and -LPS hDPCs treated with ZnO, ZnO:0.7Ca, and ZnO:1.0Ca presented similar NO production to negative control (p > 0.05) and lower production compared to positive control (p < 0.05). All NCs showed reduced ROS production compared with the positive control group both in +LPS and -LPS cells (p < 0.05). Conclusions: NCs were successfully synthesized. ZnO, ZnO:0.7Ca and ZnO:1.0Ca presented the highest percentages of cell viability, decreased ROS and NO production in +LPS cells, and maintenance of NO production at basal levels.

The Influence of Sodium on the Calcium Release from Cardiac Mitochondria (심장근(心臟筋) mithochondria의 $Ca^{++}$유리에 대한 $Na^+$의 영향(影響))

  • Kim, Yong-Sik;Park, Chan-Woong;Kim, Myung-Suk
    • The Korean Journal of Pharmacology
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    • v.17 no.1 s.28
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    • pp.1-8
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    • 1981
  • The $Na^+$-induced calcium release and the effect of sodium on the transmitochondrial calcium flux were observed in mitochondria isolated from pig ventricular myocardium by Milipore filtration technique using radioisotope $^{45}Ca$. The release of calcium from cardiac mitochondria was induced by small amount of sodium, and was promoted by increasing sodium concentration in the incubation medium. The extent of the $Na^+$-induced calcium release was much greater in the absence of extramitochondrial calcium than in the presence of calcium. At steady state of calcium binding on the mitochondrial membrane unidirectional calcium influx was inhibited by sodium and unidirectional calcium efflux was increased., From the above results, it was suggested that calcium might be released from cardiac mitochondria in exchange with sodium through the mediation of the postulated '$Na^+/Ca^{++}$ exchange' mechanism.

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