ABSTRACT
Aluminum dross (AD) is a waste product produced during aluminum processing and can be used to prepare mullite ceramic materials. However, the research on the preparation of mullite porous ceramics entirely from solid waste is still in the development stage. In this paper, porous mullite ceramics were successfully fabricated using a solid-phase sintering process with AD and different silicon sources (fly ash, silica dust, and gangue) as raw materials. The bulk density, apparent porosity, and compressive strength of the specimens were obtained, and the phase compositions and microstructures of the sintered specimens were measured using XRD and SEM, respectively. The average activation energy of the phase transition of fly ash, silica dust, and gangue as silicon sources were 984 kJ/mol, 1113 kJ/mol, and 741 kJ/mol, respectively. The microstructures of the mullite in the specimens were prisms, random aggregates, and needle-shaped, respectively. The formation of needle-shaped mullite combined with the substrate enhanced the mechanical strength of the porous mullite ceramics. The apparent porosity, density, and compressive strength of the specimens with gangue as the silicon source were 33.13%, 1.98 g/cm3, and 147.84 MPa, respectively, when sintered at 1300 °C for 2 h.
ABSTRACT
In this study, the hydrolysis behavior and kinetics of AlN in aluminum dross (AD) were investigated in order to better identify the steps controlling the AlN hydrolysis reaction and the factors influencing the hydrolysis rate to enhance the removal efficiency of AlN. The hydrolysis behavior of AlN, including AlN content, phase composition, chemical composition, microstructure, and element distribution, was determined by a leaching test, X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and energy dispersive spectroscopy, respectively. The results showed that increasing the leaching liquid-solid ratio as well as the temperature was helpful for the removal efficiency of AlN. When the liquid--solid ratio was 4:1, temperature was 90 °C, and leaching time was 300 min, the removal efficiency of AlN reached 89.05%. The kinetics were described using the unreacted core model, and when the temperature was 30-40, 50-70, and 80-90 °C, the hydrolysis reaction rate of AlN was controlled by boundary layer diffusion, chemical reaction control, and product layer diffusion control, respectively.
ABSTRACT
Objective To discuss the technical specifications of current high-frequency electrotome detection,to avoid the hidden danger of high-frequency electrotome power detectors,and to measure the leakage current of different kinds of highfrequency electrotome accurately.Methods The power and leakage current of the high frequency electrotome were measured by FLUCK QA-ES Ⅱ high frequency electrotome analyzer.The safety of the two methods was compared before and after the improvement of the power measurement.Four parameters of leakage current were repeatedly measured with the ways of high frequency earthing and high frequency isolation respectively.The maximum measurement of leakage current was recorded.Results The improved connection method was safe in the power measurement.For the high-frequency electrotome in the model of high frequency earthing,the values of leakage current were restrained within the range of error with two ways of monopolar loading operation electrode and neutral electrode.For the high-frequency electrotome in the model of high frequency isolation,the values of leakage current were limited within the range of error withtwo ways of monopolar empty operation electrode and neutral electrode.Conclusion The improved high-frequency electrotome power detection method is safe for detectors.The data obtained from the leakage current detection method using the national standard correction method reflect the actual state of the high-frequency electrotome,when the electrotome with earth as the reference is used to detect the leakage current with loading or the insulated electrotome is applied to measuring the leakage current with no loading.
ABSTRACT
Objective To design and implement an automatic analysis and evaluation system for the image parameters of medical MRI quality testing.Methods The system was developed and debugged by the study on MRI image quality parameters,the image denoising,integration,extraction and etc by MATLAB processing platform as well as the comparison and comparative calculation of the obtained data.Results The system replaced manual operation by auto processing and parameters analysis of MRI quality inspection image.Conclusion The system enhances the efficiency and avoids artificial error,and has a promising prospect in the future.
ABSTRACT
Objective To discuss the technical specifications of current high-frequency electrotome detection,to avoid the hidden danger of high-frequency electrotome power detectors,and to measure the leakage current of different kinds of highfrequency electrotome accurately.Methods The power and leakage current of the high frequency electrotome were measured by FLUCK QA-ES Ⅱ high frequency electrotome analyzer.The safety of the two methods was compared before and after the improvement of the power measurement.Four parameters of leakage current were repeatedly measured with the ways of high frequency earthing and high frequency isolation respectively.The maximum measurement of leakage current was recorded.Results The improved connection method was safe in the power measurement.For the high-frequency electrotome in the model of high frequency earthing,the values of leakage current were restrained within the range of error with two ways of monopolar loading operation electrode and neutral electrode.For the high-frequency electrotome in the model of high frequency isolation,the values of leakage current were limited within the range of error withtwo ways of monopolar empty operation electrode and neutral electrode.Conclusion The improved high-frequency electrotome power detection method is safe for detectors.The data obtained from the leakage current detection method using the national standard correction method reflect the actual state of the high-frequency electrotome,when the electrotome with earth as the reference is used to detect the leakage current with loading or the insulated electrotome is applied to measuring the leakage current with no loading.
ABSTRACT
Objective To design and implement an automatic analysis and evaluation system for the image parameters of medical MRI quality testing.Methods The system was developed and debugged by the study on MRI image quality parameters,the image denoising,integration,extraction and etc by MATLAB processing platform as well as the comparison and comparative calculation of the obtained data.Results The system replaced manual operation by auto processing and parameters analysis of MRI quality inspection image.Conclusion The system enhances the efficiency and avoids artificial error,and has a promising prospect in the future.
