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Yong Qing Fu - One of the best experts on this subject based on the ideXlab platform.
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Nebulization using zno si surface acoustic wave devices with focused interdigitated transducers
Surface & Coatings Technology, 2019Co-Authors: Jian Zhou, Yifan Li, Shurong Dong, Huigao Duan, Yong Qing FuAbstract:Abstract Propagation of surface acoustic waves (SAWs) on bulk piezoelectric substrates such as LiNbO3 and quartz, exhibits an in-plane anisotropic effect due to their crystal cut orientations. Thin film SAW devices, such as those based on ZnO or AlN, offer potential advantages, including isotropic wave velocities in all in-plane directions, higher power handling capability, and potentially lower failure rates. This paper reports experimental and simulation results of Nebulization behaviour for water droplets using ZnO/Si surface acoustic wave devices with focused interdigital transducers (IDTs). Post-deposition annealing of the films at various temperatures was applied to improve the quality of the sputtering-deposited ZnO films, and 500 °C was found to be the optimal annealing temperature. Thin film ZnO/Si focused SAW devices were fabricated using the IDT designs with arc angles ranging from 30° to 90°. Nebulization was significantly enhanced with increasing the arc angles of the IDTs, e.g., increased Nebulization rate, reduced critical powers required to initialise Nebulization, and concentration of the nebulised plume into a narrower size of spray. Effects of applied RF power and droplet size have been systematically studied, and increased RF power and reduced droplet size significantly enhanced the Nebulization phenomena.
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Nebulization of water glycerol droplets generated by zno si surface acoustic wave devices
Microfluidics and Nanofluidics, 2015Co-Authors: A P Dennison, Yifan Li, Xiao Tao Zu, C L Mackay, Patrick R R Langridgesmith, A J Walton, Yong Qing FuAbstract:Efficient Nebulization of liquid sessile droplets (water and water/glycerol mixtures) was investigated using standing waves generated using ZnO/Si surface acoustic wave (SAW) devices under different RF powers, frequencies and liquid viscosity (varied glycol concentrations in water). At such high RF powers, there are strong competitions between vertical jetting and Nebulization. At lower SAW frequencies of 12.3 and 23.37 MHz, significant capillary waves and large satellite droplets were generated before Nebulization could be observed. At frequencies between 23.37 and 37.2 MHz, spreading, displacement or occasionally jetting of the parent sessile droplet was frequently observed before a significant Nebulization occurred. When the SAW frequencies were increased from 44.44 to 63.3 MHz, the minimum RF power to initiate droplet Nebulization was found to increase significantly, and jetting of the parent droplet before Nebulization became significant, although the average size of the nebulized particles and ejected satellite droplets appeared to decrease with an increase in frequency. With the increase of glycerol concentration in the test sessile droplets (or increase in liquid viscosity), Nebulization became difficult due to the increased SAW damping rate inside the liquid. Acoustic heating effects were characterized to be insignificant and did not show apparent contributions to the Nebulization process due to silicon substrate’s natural effect as an effective heat sink and the employment of a metallic holder beneath the ZnO/Si SAW device substrates.
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surface acoustic wave Nebulization on nanocrystalline zno film
Applied Physics Letters, 2012Co-Authors: Yong Qing Fu, Yifan Li, Chao Zhao, Frank Placido, A J WaltonAbstract:Surface acoustic wave(SAW) Nebulization/atomization has been realised on thin ZnOfilm based SAWdevices. The surface acoustic wave Nebulization (SAWN) process has been observed to produce significant mist generation and ejected satellitedroplets. By modifying the geometry of the interdigitated transducers to reduce the wavelengths from 400 μm to 120 μm, higher frequency SAWN has been achieved by increasing radio frequency driving frequencies from 11.8 MHz to 37.2 MHz, respectively. Compared with the commonly used LiNbO3 SAWN devices,ZnOfilmdevices exhibit better thermal dissipation, and to date, they have shown no susceptibility to substrate failure during fabrication or operation. They also have the added advantage of the technology being suitable for direct integration with microsystems and integrated circuit microelectronics.
Yifan Li - One of the best experts on this subject based on the ideXlab platform.
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Nebulization using zno si surface acoustic wave devices with focused interdigitated transducers
Surface & Coatings Technology, 2019Co-Authors: Jian Zhou, Yifan Li, Shurong Dong, Huigao Duan, Yong Qing FuAbstract:Abstract Propagation of surface acoustic waves (SAWs) on bulk piezoelectric substrates such as LiNbO3 and quartz, exhibits an in-plane anisotropic effect due to their crystal cut orientations. Thin film SAW devices, such as those based on ZnO or AlN, offer potential advantages, including isotropic wave velocities in all in-plane directions, higher power handling capability, and potentially lower failure rates. This paper reports experimental and simulation results of Nebulization behaviour for water droplets using ZnO/Si surface acoustic wave devices with focused interdigital transducers (IDTs). Post-deposition annealing of the films at various temperatures was applied to improve the quality of the sputtering-deposited ZnO films, and 500 °C was found to be the optimal annealing temperature. Thin film ZnO/Si focused SAW devices were fabricated using the IDT designs with arc angles ranging from 30° to 90°. Nebulization was significantly enhanced with increasing the arc angles of the IDTs, e.g., increased Nebulization rate, reduced critical powers required to initialise Nebulization, and concentration of the nebulised plume into a narrower size of spray. Effects of applied RF power and droplet size have been systematically studied, and increased RF power and reduced droplet size significantly enhanced the Nebulization phenomena.
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Nebulization of water glycerol droplets generated by zno si surface acoustic wave devices
Microfluidics and Nanofluidics, 2015Co-Authors: A P Dennison, Yifan Li, Xiao Tao Zu, C L Mackay, Patrick R R Langridgesmith, A J Walton, Yong Qing FuAbstract:Efficient Nebulization of liquid sessile droplets (water and water/glycerol mixtures) was investigated using standing waves generated using ZnO/Si surface acoustic wave (SAW) devices under different RF powers, frequencies and liquid viscosity (varied glycol concentrations in water). At such high RF powers, there are strong competitions between vertical jetting and Nebulization. At lower SAW frequencies of 12.3 and 23.37 MHz, significant capillary waves and large satellite droplets were generated before Nebulization could be observed. At frequencies between 23.37 and 37.2 MHz, spreading, displacement or occasionally jetting of the parent sessile droplet was frequently observed before a significant Nebulization occurred. When the SAW frequencies were increased from 44.44 to 63.3 MHz, the minimum RF power to initiate droplet Nebulization was found to increase significantly, and jetting of the parent droplet before Nebulization became significant, although the average size of the nebulized particles and ejected satellite droplets appeared to decrease with an increase in frequency. With the increase of glycerol concentration in the test sessile droplets (or increase in liquid viscosity), Nebulization became difficult due to the increased SAW damping rate inside the liquid. Acoustic heating effects were characterized to be insignificant and did not show apparent contributions to the Nebulization process due to silicon substrate’s natural effect as an effective heat sink and the employment of a metallic holder beneath the ZnO/Si SAW device substrates.
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surface acoustic wave Nebulization on nanocrystalline zno film
Applied Physics Letters, 2012Co-Authors: Yong Qing Fu, Yifan Li, Chao Zhao, Frank Placido, A J WaltonAbstract:Surface acoustic wave(SAW) Nebulization/atomization has been realised on thin ZnOfilm based SAWdevices. The surface acoustic wave Nebulization (SAWN) process has been observed to produce significant mist generation and ejected satellitedroplets. By modifying the geometry of the interdigitated transducers to reduce the wavelengths from 400 μm to 120 μm, higher frequency SAWN has been achieved by increasing radio frequency driving frequencies from 11.8 MHz to 37.2 MHz, respectively. Compared with the commonly used LiNbO3 SAWN devices,ZnOfilmdevices exhibit better thermal dissipation, and to date, they have shown no susceptibility to substrate failure during fabrication or operation. They also have the added advantage of the technology being suitable for direct integration with microsystems and integrated circuit microelectronics.
A J Walton - One of the best experts on this subject based on the ideXlab platform.
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Nebulization of water glycerol droplets generated by zno si surface acoustic wave devices
Microfluidics and Nanofluidics, 2015Co-Authors: A P Dennison, Yifan Li, Xiao Tao Zu, C L Mackay, Patrick R R Langridgesmith, A J Walton, Yong Qing FuAbstract:Efficient Nebulization of liquid sessile droplets (water and water/glycerol mixtures) was investigated using standing waves generated using ZnO/Si surface acoustic wave (SAW) devices under different RF powers, frequencies and liquid viscosity (varied glycol concentrations in water). At such high RF powers, there are strong competitions between vertical jetting and Nebulization. At lower SAW frequencies of 12.3 and 23.37 MHz, significant capillary waves and large satellite droplets were generated before Nebulization could be observed. At frequencies between 23.37 and 37.2 MHz, spreading, displacement or occasionally jetting of the parent sessile droplet was frequently observed before a significant Nebulization occurred. When the SAW frequencies were increased from 44.44 to 63.3 MHz, the minimum RF power to initiate droplet Nebulization was found to increase significantly, and jetting of the parent droplet before Nebulization became significant, although the average size of the nebulized particles and ejected satellite droplets appeared to decrease with an increase in frequency. With the increase of glycerol concentration in the test sessile droplets (or increase in liquid viscosity), Nebulization became difficult due to the increased SAW damping rate inside the liquid. Acoustic heating effects were characterized to be insignificant and did not show apparent contributions to the Nebulization process due to silicon substrate’s natural effect as an effective heat sink and the employment of a metallic holder beneath the ZnO/Si SAW device substrates.
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surface acoustic wave Nebulization on nanocrystalline zno film
Applied Physics Letters, 2012Co-Authors: Yong Qing Fu, Yifan Li, Chao Zhao, Frank Placido, A J WaltonAbstract:Surface acoustic wave(SAW) Nebulization/atomization has been realised on thin ZnOfilm based SAWdevices. The surface acoustic wave Nebulization (SAWN) process has been observed to produce significant mist generation and ejected satellitedroplets. By modifying the geometry of the interdigitated transducers to reduce the wavelengths from 400 μm to 120 μm, higher frequency SAWN has been achieved by increasing radio frequency driving frequencies from 11.8 MHz to 37.2 MHz, respectively. Compared with the commonly used LiNbO3 SAWN devices,ZnOfilmdevices exhibit better thermal dissipation, and to date, they have shown no susceptibility to substrate failure during fabrication or operation. They also have the added advantage of the technology being suitable for direct integration with microsystems and integrated circuit microelectronics.
Stephan Ehrmann - One of the best experts on this subject based on the ideXlab platform.
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nasal high flow bronchodilator Nebulization a randomized cross over study
Annals of Intensive Care, 2018Co-Authors: Francois Reminiac, L Vecellio, Laetitia Bodetcontentin, Valerie Gissot, Deborah Le Pennec, Charlotte Salmon Gandonniere, Maria Cabrera, P F Dequin, Laurent Plantier, Stephan EhrmannAbstract:There is an absence of controlled clinical data showing bronchodilation effectiveness after Nebulization via nasal high-flow therapy circuits. Twenty-five patients with reversible airflow obstruction received, in a randomized order: (1) 2.5 mg albuterol delivered via a jet nebulizer with a facial mask; (2) 2.5 mg albuterol delivered via a vibrating mesh nebulizer placed downstream of a nasal high-flow humidification chamber (30 L/min and 37 °C); and (3) nasal high-flow therapy without Nebulization. All three conditions induced significant individual increases in forced expiratory volume in one second (FEV1) compared to baseline. The median change was similar after facial mask Nebulization [+ 350 mL (+ 180; + 550); + 18% (+ 8; + 30)] and nasal high flow with Nebulization [+ 330 mL (+ 140; + 390); + 16% (+ 5; + 24)], p = 0.11. However, it was significantly lower after nasal high-flow therapy without Nebulization [+ 50 mL (− 10; + 220); + 3% (− 1; + 8)], p = 0.0009. FEV1 increases after facial mask and nasal high-flow Nebulization as well as residual volume decreases were well correlated (p < 0.0001 and p = 0.01). Both techniques showed good agreement in terms of airflow obstruction reversibility (kappa 0.60). Albuterol vibrating mesh Nebulization within a nasal high-flow circuit induces similar bronchodilation to standard facial mask jet Nebulization. Beyond pharmacological bronchodilation, nasal high flow by itself may induce small but significant bronchodilation.
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ventilator integrated jet Nebulization systems tidal volume control and efficiency of synchronization
Respiratory Care, 2014Co-Authors: Stephan Ehrmann, Deborah Le Pennec, Aissam Lyazidi, Bruno Louis, Daniel Isabey, Laurent Brochard, Gabriela ApiousbirleaAbstract:BACKGROUND: Jet nebulizers constitute the aerosolization devices most frequently used during mechanical ventilation. Continuous Nebulization can influence the delivered tidal volume (VT) and lead to significant medication loss during expiration. Ventilators thus provide integrated jet Nebulization systems that are synchronized during inspiration and ostensibly keep VT constant. METHODS: This was a bench study of systems integrated in the Evita XL, Avea, Galileo, and G5 ventilators. The VT delivered with and without Nebulization, the inspiratory synchronization of Nebulization, and the aerosol deposition were measured with 2 locations of the nebulizer. RESULTS: Changes in VT with the nebulizer were below 20 mL and below 10% of set VT for all ventilators. Synchronization was good at the beginning of insufflation, but prolonged Nebulization was observed with all ventilators at the end of insufflation, until up to 1 s during expiration: 5–80% of Nebulization occurred during expiration with significant aerosol loss in the expiratory limb. Synchrony could be improved by (1) reducing gas compression/decompression phenomena proximal to the jet nebulizer and (2) increasing inspiratory time, which reduced the amount of Nebulization occurring during expiration. Placing the nebulizer upstream in the inspiratory limb did not affect inspiratory synchrony but allowed reduction of the amount of aerosol lost in the expiratory limb. CONCLUSIONS: Jet nebulizer systems integrated in the tested ventilators are reliable in terms of VT control. Gas compression in tubing driving gas to the nebulizer delays synchronization and reduces Nebulization yield if the nebulizer is placed close to the Y-piece. Increasing inspiratory time with no end-inspiratory pause reduces the expiratory loss of medication if placement of the nebulizer upstream in the inspiratory limb is not feasible.
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Aerosol therapy during mechanical ventilation: an international survey
Intensive Care Medicine, 2013Co-Authors: Stephan Ehrmann, Daniel Isabey, Laurent Brochard, Ferran Roche-campo, Giuseppe Francesco Sferrazza Papa, Gabriela Apiou-sbirleaAbstract:Purpose To describe the practice, knowledge and beliefs about aerosol therapy during mechanical ventilation in an international sample of physicians working in intensive care units (ICU). Methods A self-administered survey was emailed to physicians who worked regularly in ICUs. The physicians were identified from the databases of the European and French societies of intensive care medicine and the REVA network. Results Of the 1,192 responses (15 % response rate), 854 were analyzed. Of the respondents, who represented 611 departments in 70 countries, 99 % reported using aerosol therapy during mechanical ventilation (including non-invasive), 43 % exclusively used nebulizers and 55 % also used metered dose inhalers. Nebulization relied on jet, ultrasonic and vibrating mesh nebulizers (55 %, 44 % and 14 % of respondents, respectively). Bronchodilators and steroids were the most frequently delivered drugs, and 80 % of respondents had a positive opinion concerning nebulized colistin and 30 % reported the use of nebulized antibiotics at least every other month. During Nebulization, ventilator settings were never changed by 77 % of respondents, 65 % reported placing a filter on the expiratory limb, and of these 28 % never changed it. Only 22 % of respondents using heated humidifiers reported turning them off during Nebulization. Specific knowledge about droplet size and Nebulization yield was poor. A majority of respondents (87 %) thought that ultrasonic nebulizers outperform jet nebulizers, while 69 % had no opinion concerning mesh nebulizers. Conclusions Aerosol therapy during mechanical ventilation is used by over 95 % of intensivists, mostly for bronchodilator and steroid administration, but also frequently for antibiotics. The current scientific knowledge about optimal implementation seemed infrequently applied, suggesting the need for educational programs and research focusing on a better bench-to-bedside transfer of knowledge.
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Pharmacokinetics of high-dose nebulized amikacin in mechanically ventilated healthy subjects
Intensive Care Medicine, 2008Co-Authors: Stephan Ehrmann, Laurent Vecellio, Emmanuelle Mercier, David Ternant, Gilles Paintaud, Pierre-françois DequinAbstract:Objective Nebulized amikacin may be an attractive option for the treatment of lung infections. Low systemic absorption may permit the use of high doses, leading to high lung concentrations without systemic toxicity. We evaluated the pharmacokinetics and safety of an optimized high-dose amikacin Nebulization technique. Design in vitro and in vivo pharmacokinetic study. Patients and participants Six healthy volunteers (age 21–30 years, weight 49–68 kg). Interventions The Aeroneb Pro nebulizer with an Idehaler vertical spacer was evaluated in a bench study. Amikacin was administered intravenously (15 mg/kg) and nebulized (40, 50, and 60 mg/kg) during noninvasive pressure-support ventilation through a mouthpiece. Measurements and results Median (interquartile range) in vitro inhaled fraction was 31% (30–32) and inhalable output was 681 mg/h (630–743). Serum concentrations after Nebulization were less than or equal to those after infusion. The area under the serum concentration curve was significantly higher after infusion (138 mg h^–1l^–1, 122–143) than after Nebulization (49 mg h^–1l^–1, 39–55, at 40 mg/kg; 63, 53–67 at 50; 66, 50–71, at 60). Peak serum concentration was also higher after infusion: 48 mg/l (45–49) after infusion compared to 8.2 (5.6–8.7), 9.2 (7.6–10.2), and 9.2 (5.2–10.3), respectively. Mean absorption times after Nebulization were 2 h 24 min (2,07–2,45), 2 h 21 min (2,07–2,35), and 2 h 5 min (2,00–2,25), respectively. No side effect was observed. Conclusions Nebulization of up to 60 mg/kg amikacin appears to be safe in healthy subjects and associated with lower serum concentrations than a 15 mg/kg infusion.
Pengyuan Yang - One of the best experts on this subject based on the ideXlab platform.
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slurry Nebulization in plasmas for analysis of advanced ceramic materials
Journal of Analytical Atomic Spectrometry, 2014Co-Authors: Zheng Wang, Pengyuan YangAbstract:Slurry Nebulization in plasmas has advantages of simplicity, high speed, low cost, minimized analyte loss, and low risk of sample contamination, but it has not been very widely adopted. However, the study of advanced ceramic materials has recently renewed enthusiasm for this technique. In this paper, the current state of research on slurry Nebulization in plasmas for the analysis of advanced materials is thoroughly surveyed. Sample preparation, sample characterization, and modifications of the instrumentation necessary for slurry Nebulization are reviewed, along with calibration procedures and studies on fundamental issues. Finally, the applications of this method to a variety of advanced materials are summarized, and the outlook for this method is discussed.
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Slurry Nebulization in plasmas for analysis of advanced ceramic materials
Journal of Analytical Atomic Spectrometry, 2014Co-Authors: Zheng Wang, Pengyuan YangAbstract:The current state of research on slurry Nebulization in plasmas for the analysis of advanced materials is thoroughly surveyed.Slurry Nebulization in plasmas has advantages of simplicity, high speed, low cost, minimized analyte loss, and low risk of sample contamination, but it has not been very widely adopted. However, the study of advanced ceramic materials has recently renewed enthusiasm for this technique. In this paper, the current state of research on slurry Nebulization in plasmas for the analysis of advanced materials is thoroughly surveyed. Sample preparation, sample characterization, and modifications of the instrumentation necessary for slurry Nebulization are reviewed, along with calibration procedures and studies on fundamental issues. Finally, the applications of this method to a variety of advanced materials are summarized, and the outlook for this method is discussed.
