The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Hong Zhao - One of the best experts on this subject based on the ideXlab platform.
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A study of hydroxyapatite/Calcium Sulphate bioceramics
Ceramics International, 2005Co-Authors: De’an Yang, Zi Yang, Hong ZhaoAbstract:Hydroxyapatite/Calcium Sulphate anhydrate (HAP/CSA) powders were prepared by the wet precipitation method at pH 10. HAP/CSA ceramics were sintered at 1000 °C, and then degraded in citric buffer solution at 37 °C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study phase composition and microstructure of the ceramics. The results showed that HAP/CSA was a kind of potential in situ pore forming bioceramics.
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a study of hydroxyapatite Calcium Sulphate bioceramics
Ceramics International, 2005Co-Authors: Dean Yang, Zi Yang, Hong ZhaoAbstract:Hydroxyapatite/Calcium Sulphate anhydrate (HAP/CSA) powders were prepared by the wet precipitation method at pH 10. HAP/CSA ceramics were sintered at 1000 °C, and then degraded in citric buffer solution at 37 °C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study phase composition and microstructure of the ceramics. The results showed that HAP/CSA was a kind of potential in situ pore forming bioceramics.
Bart Van Der Bruggen - One of the best experts on this subject based on the ideXlab platform.
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The presence of ferric iron promotes Calcium Sulphate scaling in reverse osmosis processes
Desalination, 2016Co-Authors: Martin Bystrianský, Oded Nir, Marek Šír, Zuzana Honzajková, Radek Vurm, Pavla Hrychová, Antonín Bervic, Bart Van Der BruggenAbstract:Abstract Calcium Sulphate is one of the most common components responsible for inorganic scaling in industrial heat exchangers and desalination plants. Insoluble scales cause problems like material degradation and a decrease of process efficiency. This is a major challenge for wastewater containing high concentrations of Calcium Sulphate, e.g. power plant ash deposit site leachates. Treatment of such water by means of reverse osmosis is considered in this study. It was found that iron ions present in the solution in low concentration can affect the scaling behaviour. If present, iron shortens both induction time and overall time of Calcium Sulphate crystallization from its supersaturated solution. Modelling, jar tests and RO separation tests were made to examine this phenomenon. Model solutions supersaturated by Calcium Sulphate were prepared in various conditions, always in two parallels: a solution containing iron ions and a solution without iron. The difference (induction time, crystal formation rate) is significant at lower supersaturation while at high supersaturation the results are very similar due to quick crystallization. When treating such supersaturated solution (or solution close to saturation) two main possible ways offer: removing iron prior to treatment (e.g. by aeration or coagulation) or preventing scale formation by adding antiscalants.
Zi Yang - One of the best experts on this subject based on the ideXlab platform.
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A study of hydroxyapatite/Calcium Sulphate bioceramics
Ceramics International, 2005Co-Authors: De’an Yang, Zi Yang, Hong ZhaoAbstract:Hydroxyapatite/Calcium Sulphate anhydrate (HAP/CSA) powders were prepared by the wet precipitation method at pH 10. HAP/CSA ceramics were sintered at 1000 °C, and then degraded in citric buffer solution at 37 °C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study phase composition and microstructure of the ceramics. The results showed that HAP/CSA was a kind of potential in situ pore forming bioceramics.
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a study of hydroxyapatite Calcium Sulphate bioceramics
Ceramics International, 2005Co-Authors: Dean Yang, Zi Yang, Hong ZhaoAbstract:Hydroxyapatite/Calcium Sulphate anhydrate (HAP/CSA) powders were prepared by the wet precipitation method at pH 10. HAP/CSA ceramics were sintered at 1000 °C, and then degraded in citric buffer solution at 37 °C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study phase composition and microstructure of the ceramics. The results showed that HAP/CSA was a kind of potential in situ pore forming bioceramics.
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Synthesis of Calcium phosphate/Calcium Sulphate powder
Materials Chemistry and Physics, 2004Co-Authors: Chong Liang, Yang Dean, Zi YangAbstract:Calcium phosphate/Calcium Sulphate powders were synthesized by wet method. The effects of the initial Calcium/phosphorus molar ratio and the pH of the solution on the microstructure and phase composition were studied by SEM, XRD, and FTIR spectroscopy. The results show that the pH value was the predominant parameter for the particle shape and the final phase composition of the calcined powders.
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Synthesis of Calcium phosphate/Calcium Sulphate powder
Materials Chemistry and Physics, 2004Co-Authors: Chong Liang, De’an Yang, Zi YangAbstract:Calcium phosphate/Calcium Sulphate powders were synthesized by wet method. The effects of the initial Calcium/phosphorus molar ratio and the pH of the solution on the microstructure and phase composition were studied by SEM, XRD, and FTIR spectroscopy. The results show that the pH value was the predominant parameter for the particle shape and the final phase composition of the calcined powders. © 2004 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex
Martin Bystrianský - One of the best experts on this subject based on the ideXlab platform.
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The presence of ferric iron promotes Calcium Sulphate scaling in reverse osmosis processes
Desalination, 2016Co-Authors: Martin Bystrianský, Oded Nir, Marek Šír, Zuzana Honzajková, Radek Vurm, Pavla Hrychová, Antonín Bervic, Bart Van Der BruggenAbstract:Abstract Calcium Sulphate is one of the most common components responsible for inorganic scaling in industrial heat exchangers and desalination plants. Insoluble scales cause problems like material degradation and a decrease of process efficiency. This is a major challenge for wastewater containing high concentrations of Calcium Sulphate, e.g. power plant ash deposit site leachates. Treatment of such water by means of reverse osmosis is considered in this study. It was found that iron ions present in the solution in low concentration can affect the scaling behaviour. If present, iron shortens both induction time and overall time of Calcium Sulphate crystallization from its supersaturated solution. Modelling, jar tests and RO separation tests were made to examine this phenomenon. Model solutions supersaturated by Calcium Sulphate were prepared in various conditions, always in two parallels: a solution containing iron ions and a solution without iron. The difference (induction time, crystal formation rate) is significant at lower supersaturation while at high supersaturation the results are very similar due to quick crystallization. When treating such supersaturated solution (or solution close to saturation) two main possible ways offer: removing iron prior to treatment (e.g. by aeration or coagulation) or preventing scale formation by adding antiscalants.
Andrew L. Rohl - One of the best experts on this subject based on the ideXlab platform.
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Effects of temperature on the scaling of Calcium Sulphate in pipes
Powder Technology, 2006Co-Authors: Tung A. Hoang, H. Ming Ang, Andrew L. RohlAbstract:Abstract Calcium Sulphate scaling is a serious problem encountered in many industrial and domestic applications. Supersaturation has been proven to be the major driving force of scale formation, but the solubility of Calcium Sulphate changes with temperature. The main purpose of this work is to investigate the effects of temperature on the formation of Calcium Sulphate scales in pipes, using a pipe flow system. Various levels of supersaturation of the Calcium Sulphate solution have been employed at different temperatures. Results indicated that higher temperature produced a large increase of scale amounts and a significant decrease of induction periods. Many forms of hydrated Calcium Sulphate were created at high temperature. The relationship between deposited scale mass and temperature was deduced from experimental data. From the relationship between induction period and temperature activation energies of the surface nucleation were estimated to be in the range of 42 to 48 kJ mol − 1 .
