http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : V.M. Castaño (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Studies on the precipitation behavior of calcium phosphate solutions
S. Recillas,V. Rodríguez-Lugo,M. L. Montero,S.Viquez-Cano,L. Hernandez,V.M. Castaño 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.1
The chemical equilibrium of phosphate aqueous solutions is discussed. To obtain the concentration of the species in solution as a function of pH, we used an acid-base equilibria system, complex formation equilibria, and balance mass equations; and to resolve the non-linear equation system we used a computer program PV-WAVE with ZEROSYS subroutine function. It will be demonstrated that the chemical composition of the calcium phosphate precipitate depends decisively on the species concentration in solution. Also, the pH and the reaction conditions for the selective precipitation of hydroxyapatite are critical. A small variation of these conditions allows either the coprecipitation of other phosphates or no precipitation at all. The solubility variation of the phosphates as a function of the solution ionic force is also discussed. Finally, proper reaction conditions are proposed for hydroxyapatite growth starting from saturated solutions of calcium phosphates. The chemical equilibrium of phosphate aqueous solutions is discussed. To obtain the concentration of the species in solution as a function of pH, we used an acid-base equilibria system, complex formation equilibria, and balance mass equations; and to resolve the non-linear equation system we used a computer program PV-WAVE with ZEROSYS subroutine function. It will be demonstrated that the chemical composition of the calcium phosphate precipitate depends decisively on the species concentration in solution. Also, the pH and the reaction conditions for the selective precipitation of hydroxyapatite are critical. A small variation of these conditions allows either the coprecipitation of other phosphates or no precipitation at all. The solubility variation of the phosphates as a function of the solution ionic force is also discussed. Finally, proper reaction conditions are proposed for hydroxyapatite growth starting from saturated solutions of calcium phosphates.
-
Thermoluminescence of NaCl:Cu Sintered Phosphors Exposed to Beta Irradiation
R. Bernal,C. Cruz-Vázquez,F. Brown,W. Tostado-García,R. Pérez-Salas,V.M. Castaño 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4
NaCl:Cu pellet-shaped phosphors were synthesized through a sintering process. Some samples were exposed to beta irradiation in order to investigate their thermoluminescence properties and capabilities to be used in detecting and measuring ionizing radiation. The glow curves reveal at least four thermoluminescence peaks below 250°C, and a main one above 300°C when a 5°C/s heating rate is used. The lowest temperature peak vanishes in less than 3 min after irradiation, giving rise to an intense afterglow luminescence, potentially useful for in situ non-thermoluminescence dosimetry, and the next remains for about 3 h, but the high temperature one exhibits no important changes after that time. The thermoluminescence intensity increased as the radiation dose increased in the 0.417 - 25.0 Gy dose range. Because the position and the remarkable stability of the higher temperature peak, besides the strong afterglow produced by the fast decaying of the lower temperature peak, it is concluded that these phosphors are very suitable candidates to be used in both thermoluminescence and non thermoluminescence dosimetry of ionizing radiation, having advantages over monocrystals of similar composition. The synthesis route here followed can be reproduced in standard college laboratories, and thermoluminescence be measured in home-made systems, allowing design practices for interdisciplinary physics, chemistry electronics, and materials science students.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
