The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
F. Ohene - One of the best experts on this subject based on the ideXlab platform.
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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly progress report, April 1, 1996--June 30, 1996
1996Co-Authors: F. OheneAbstract:The overall objective of this project is to perform experiments to understand the effect of coal beneficiation processes and high shear rheological properties on the atomization of coal-water slurries (CWS). In the atomization studies, the mean drop size of the CWS sprays will be determined at various air-to CWS. A correlation between the high shear rheological properties, particle size distributions and the atomization will be made in order to determine the influence of these parameters on the atomization of CWS. The viscoelastic behavior of several concentrations of the slurries under study: Heavy Cleaned, Flotation Cleaned and Uncleaned samples were measured. The results obtained will be correlated with the atomization data. The effect of the viscoelastic property on the atomization is being investigated further, and the results will be reported in the final report
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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly report, April 1, 1996--June 30, 1996
1996Co-Authors: F. OheneAbstract:The overall objective of this project is to perform experiments to understand the effect of coal beneficiation processes and high shear rheological properties on the atomization of coal-water slurries (CWS). In the atomization studies, the mean drop size of the CWS sprays will be determined at various air-to CWS. a correlation between the high shear rheological properties, particle size distributions and the atomization will be made in order to determine the influence of these parameters on the atomization of CWS. This report covers the tasks completed during the period April 1, 1996 to June 30, 1996 including viscoelastic behavior studies
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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly progress report, July 1, 1995--September 30, 1995
1996Co-Authors: F. OheneAbstract:The overall objective of this project is to perform experiments to understand the effect of coal beneficiation processes and high shear rheological properties on the atomization of coal-water slurries (CWS). In the atomization studies, the mean drop size of the CWS sprays will be determined at various air-to CWS. A correlation between the high shear rheological properties, particle size distributions and the atomization will be made in order to determine the influence of these parameters on the atomization of CWS.
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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly progress report, January 1--March 30, 1995
1995Co-Authors: F. OheneAbstract:The overall objective of this project is to perform experiments to understand the effect of coal beneficiation processes and high shear rheological properties on the atomization of coal-water slurries (CWS). In the atomization studies, the mean drop size of the CWS sprays will be determined at various air-to CWS. A correlation between the high shear rheological properties, particle size distributions and the atomization will be made in order to determine the influence of these parameters on the atomization of CWS. Results on the rheological evaluation of CWS are presented
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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly progress report, January 1--March 31, 1993
1993Co-Authors: F. OheneAbstract:The overall objective of this project is to perform experiments to understand the effect of coal beneficiation processes and high shear rheological properties on the atomization of coal-water slurries (CWS). In the atomization studies, the mean drop size of the CWS sprays will be determined at various air-to CWS. A correlation between the high shear rheological properties, particle size distributions and the atomization will be made in order to determine the influence of these parameters on the atomization of CWS. The paper discusses FTIR analysis, wet grinding, flotation cleaned coal, and heavy media cleaned coal
P. M. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Direct determination of lead in bovine liver by solid sampling with graphite furnace atomic absorption spectrometry—a comparison of tube wall atomization, platform atomization and probe atomization
Spectrochimica Acta Part B: Atomic Spectroscopy, 2001Co-Authors: Chuni L. Chakrabarti, R. Karwowska, B. R. Hollebone, P. M. JohnsonAbstract:Abstract A comparative study of three atomization techniques is presented: tube wall atomization, platform atomization and probe atomization, in graphite furnace atomic absorption spectrometry for direct determination of lead in bovine liver. Also presented is the effect of oxygen ashing on the lead atomic absorption signal and on the background absorption due to the organic matrix of bovine liver. Study of the lead atomic absorption pulses given by the three atomization techniques using a detection system having a short time constant relative to the atomization and the residence time of lead from Bovine Liver, SRM No. 1577, has provided a new insight into the atomization processes involved in the techniques. The importance of isothermal atomization in reducing or eliminating matrix interferences and the role of oxygen gas in the ashing cycle are presented and discussed.
Ni Zhe-ming - One of the best experts on this subject based on the ideXlab platform.
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Atomization efficiencies for indium and tin from different atomizer surfaces in graphite furnace atomic absorption spectrometry
Spectrochimica Acta Part B: Atomic Spectroscopy, 1997Co-Authors: Ni Zhe-mingAbstract:Atomization efficiencies for indium and tin in graphite furnaces from different atomizer surfaces, i.e. pyrolytically coated platform (PG), palladium modified pyrolytically coated platform (PdPG) and pyrolytically coated platform, modified with zirconium carbide (ZrPG), have been studied. The proportionality factor p, which relates the number of absorbing atoms to the measured absorbance, was found be almost constant for indium but relatively sensitive to atomization temperatures for tin. Both the calculated and experimental atomization efficiencies for indium and tin atomization on the three atomizer surfaces were dependent on atomization temperatures. When indium atomized from the palladium modified pyrolytically coated platform, similar calculated and experimental atomization efficiencies were obtained. But the experimental atomization efficiency for tin was found to be lower than the calculated atomization efficiency on PG and ZrPG surfaces.
Jianhui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Study on the Influencing Factors of the Atomization Rate in a Piezoceramic Vibrating Mesh Atomizer
Applied Sciences, 2020Co-Authors: Qiufeng Yan, Wanting Sun, Jianhui ZhangAbstract:On the basis of previous study in our research group, the phenomenon of the dynamic tapered angle was founded, the occurrence of atomization is regarded to derive from the combined effects of the dynamic variation of the micro-tapered aperture, and the difference between forward and reverse flow resistance has been explained by both theories and experiments. It has been revealed that the main influencing factors of the atomization rate are driving voltage, driving frequency, and so on, while the root causes of the various atomization rates still need to be further clarified. In this paper, a micro-tapered aperture worked as a micron-sized tapered flow tube valveless piezoelectric pump in periodic variation. The working principle of such a micro-tapered aperture atomizer was analyzed in detail, and the corresponding formula of the atomization rate was also established. Through measuring the atomization rates at different working frequencies (f), it was established that when the f was set as 122 kHz, the atomization rate reached a maximum value. By building the relationship between the atomization rate and voltage at a fixed resonance frequency, it can be seen that the atomization rate increased with the increase of driving voltage. Subsequently, in order to measure their atomization rates, the micro-tapered apertures of three different outlet diameters were applied, so that the atomization rate was enhanced with the increase of the micro-tapered aperture diameter. Moreover, through examining the atomization rates at different temperatures, it was observed that the atomization rate rose with increasing temperature; while changing the liquid concentration, the atomization rate was also enhanced by the increase in its concentration. Apparently, the impact factors including working frequency, driving voltage, outlet diameter, temperature, and liquid concentration all exert some effects on the atomization rate. It is worth noting that at the first stage, these influence factors indirectly work on the micro-tapered aperture structure or flow state, followed by further effects on the flow resistance. As above-mentioned, in this work, we considered that the root cause influencing the atomization rate in a piezoceramic vibrating mesh atomizer can be attributed to the flow resistance.
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Effect of the Dynamic Cone Angle on the Atomization Performance of a Piezoceramic Vibrating Mesh Atomizer
Applied Sciences, 2019Co-Authors: Chuanyu Wu, Jianhui ZhangAbstract:In this paper, we find that the dynamic cone angle of a piezoceramic atomizer is linked to periodic changes in the volume of the micro-cone hole of the atomizer, and such changes affect atomization performance. Firstly, we explained the theory of the dynamic cone angle inside the vibrating mesh atomizer. Then, we analyzed the flow status of liquid in the micro-cone hole, and the one-way flow Rof the liquid is caused by the difference of diffuser and nozzle flow resistance. The volume change of the micro-cone hole and the liquid chamber can produce atomization. Furthermore, we developed the experiment to measure the atomization rate, atomization height, and the diameter of the atomized particles. The experiments reveal that the atomization rate and height are much larger when the vibrating mesh atomizer is working in the forward path than in the reverse one. The atomization rate and atomization height increase as the working voltage increases. Meanwhile, with increasing driving voltage to the piezoceramic actuator, the atomization particle size decrease and the atomized particle size distribution is more concentrated. Finally, the size of the micro-cone hole was measured using a microscope with different direct current (DC) voltages, further demonstrating the existence of the dynamic cone angle.
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The Effect of Vibration Characteristics on the Atomization Rate in a Micro-Tapered Aperture Atomizer.
Sensors, 2018Co-Authors: Jianhui Zhang, Jun Huang, Ying WangAbstract:Because little is known about the atomization theory of a micro-tapered aperture atomizer, we investigated the vibration characteristics of this type of atomizer. The atomization mechanism of a micro-tapered aperture atomizer was described, and the atomization rate equation was deduced. As observed via microscopy, the angle of the micro-tapered aperture changes with the applied voltage, which proved the existence of a dynamic cone angle. The forward and reverse atomization rates were measured at various voltages, and the influence of the micro-tapered aperture and its variation on the atomization rate was characterized. The resonance frequency of the piezoelectric vibrator was obtained using a laser vibrometer, and the atomization rates were measured at each resonance frequency. From experiments, we found that the atomization rates at the first five resonance frequencies increased as the working frequency increased. At the fifth resonance frequency (121.1 kHz), the atomization rate was maximized (0.561 mL/min), and at the sixth resonance frequency (148.3 kHz), the atomization rate decreased significantly (0.198 mL/min). The experimental results show that the vibration characteristics of the piezoelectric vibrator have a relatively strong impact on the atomization rate. This research is expected to contribute to the manufacture of micro-tapered aperture atomizers.
Chuni L. Chakrabarti - One of the best experts on this subject based on the ideXlab platform.
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Direct determination of lead in bovine liver by solid sampling with graphite furnace atomic absorption spectrometry—a comparison of tube wall atomization, platform atomization and probe atomization
Spectrochimica Acta Part B: Atomic Spectroscopy, 2001Co-Authors: Chuni L. Chakrabarti, R. Karwowska, B. R. Hollebone, P. M. JohnsonAbstract:Abstract A comparative study of three atomization techniques is presented: tube wall atomization, platform atomization and probe atomization, in graphite furnace atomic absorption spectrometry for direct determination of lead in bovine liver. Also presented is the effect of oxygen ashing on the lead atomic absorption signal and on the background absorption due to the organic matrix of bovine liver. Study of the lead atomic absorption pulses given by the three atomization techniques using a detection system having a short time constant relative to the atomization and the residence time of lead from Bovine Liver, SRM No. 1577, has provided a new insight into the atomization processes involved in the techniques. The importance of isothermal atomization in reducing or eliminating matrix interferences and the role of oxygen gas in the ashing cycle are presented and discussed.