ORCID Profile
0000-0002-4341-9923
Current Organisations
University of Adelaide
,
Museo delle Scienze
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Publisher: AIP Publishing
Date: 05-2012
DOI: 10.1063/1.4711130
Abstract: We report the first experiment carried out on an in situ setup, which allows for detection of CO2 from catalytic CO oxidation close to a model catalyst under realistic reaction conditions by the means of planar laser-induced fluorescence (PLIF) in the mid-infrared spectral range. The onset of the catalytic reaction as a function of temperature was followed by PLIF in a steady state flow reactor. After taking into account the self-absorption of CO2, a good agreement between the detected CO2 fluorescence signal and the CO2 mass spectrometry signal was shown. The observed difference to previously measured onset temperatures for the catalytic ignition is discussed and the potential impact of IR-PLIF as a detection technique in catalysis is outlined.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.SAPHARM.2013.08.001
Abstract: Compounded progesterone (P₄) is a product that, from a clinical experience-based perspective, effectively relieves a range of symptoms. In contrast, from a conventional evidence-based medicine perspective, P₄ is ineffective. As P₄ is not a product prescribed by conventional medicine, it is unlikely to be prescribed by family doctors, which increases the barriers to utilization. Utilization of medicines is influenced by many contextual and in idual characteristics. The Behavioral Model of Health Services Use provides a multidimensional framework to conceptualize utilization of health services including medicine use. The 4 main components of this model are: contextual characteristics, in idual characteristics, health behaviors and outcomes. This paper reports on the application of The Behavioral Model of Health Services Use to medicines and shows how it can be applied to the use of P₄. The model enables some of the positive reinforcement that contributes to women continuing to use P₄ to be explained. The Behavioral Model of Health Services Use was found to offer the potential to identify and then address issues with access to prescription medicines.
Publisher: University of Chicago Press
Date: 06-2014
DOI: 10.1086/676471
Publisher: Optica Publishing Group
Date: 07-08-2008
DOI: 10.1364/OL.33.001836
Abstract: Sensitive and nonintrusive detection of HCl in reactive gas flows with high spatial and temporal resolution manner has for the first time (to our knowledge) been demonstrated using mid-infrared polarization spectroscopy (IRPS). Trace levels of HCl were prepared in an atmospheric pressure premixed CH4/O2/Ar flat flame by seeding a small amount of chloroform into the Ar flow. Detection of HCl with IRPS in the burnt region of the stoichiometric flame was performed by probing the fundamental ro-vibration transitions with a 3.2 microm tunable pulsed laser. The quantitative nature, the detection sensitivity, and the potential spectral interferences from water were investigated.
Publisher: Springer Science and Business Media LLC
Date: 25-03-2015
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 09-2010
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 03-2023
Publisher: The Optical Society
Date: 04-03-2013
DOI: 10.1364/OE.21.006028
Publisher: IEEE
Date: 06-2013
Publisher: Elsevier BV
Date: 2021
Publisher: IOP Publishing
Date: 28-02-2013
Publisher: Elsevier BV
Date: 10-2017
Publisher: Optica Publishing Group
Date: 05-08-2202
DOI: 10.1364/OL.431231
Abstract: We originally report the use of a neural network-based method for diagnosing multiple key parameters in axis-symmetric laminar sooting flames. A Bayesian optimized back propagation neural network (BPNN) is developed and applied to flame luminosity to predict the planar distribution of soot volume fraction, temperature, and primary particle diameter. The feasibility and robustness of this approach are firstly assessed using numerical modeling results and then further validated with experimental results of a series of laminar diffusion sooting flames. This proposed BPNN model-based flame luminosity approach shows high prediction accuracies, typically up to 114 K, 0.25 ppm, and 2.56 nm for soot temperature, volume fraction, and primary particle diameter, respectively. We believe that the present machine learning-assisted optical diagnostics paves a more efficient, lower costing, and high-fidelity way for multi-parameters simultaneous diagnosis in combustion and reacting flows.
Publisher: Elsevier BV
Date: 05-2013
Publisher: Informa UK Limited
Date: 17-10-2019
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 05-2017
Publisher: Springer Science and Business Media LLC
Date: 20-06-2008
Publisher: Springer Science and Business Media LLC
Date: 19-03-2020
Publisher: American Chemical Society (ACS)
Date: 05-11-2020
Publisher: Springer Science and Business Media LLC
Date: 21-01-2023
DOI: 10.1007/S00340-023-07975-3
Abstract: In this work, the structure of laminar premixed ethylene/air flat flames at low pressure are studied experimentally. The aim of the work is to exploit the spatial expansion of laminar 1D flames and advanced laser techniques to better understand the conditions and precursors affecting soot particles inception. Soot volume fraction ( f v ) profiles were measured using laser-induced incandescence (LII), while spatial distribution of the CH * and C 2 * radicals was measured using spatially resolved emission spectroscopy. Spatially resolved laser-induced fluorescence has been used to record emission from 2–3 rings, 3–4 rings and 5 rings. The temperature of soot particles ( T s ) was evaluated through fitting the spectrally resolved soot luminosity, while flame gaseous temperature ( T g ) was measured using a fine thermocouple. The laminar flow velocity was modeled and used to evaluate the reaction time at each HAB. Taking advantage of the expanded flame structure at low pressure, the profiles of CH * , C 2 * , soot and temperatures, as a function of the height above the burner, were well resolved. It was found that CH * and C 2 * chemiluminescence overlap in space. The thickness of CH * layer is larger than that of C 2 * , and it peaks at slightly different location, CH * appears approximately 1 mm before C 2 * . The distance between the two peaks decreases linearly with the increase in pressure. The lowest value of the initial soot volume fraction ( f v ) was 0.19 ppb, measured at pressure 27 kPa. It was found that f v scales with the pressure following a power function of the form f v α Pr n , where n is 2.15 ± 0.7. It was observed that, in all the flames investigated, the initial soot particles first appear at a common critical inception temperature, T inception , of 1465 ± 66 K. It was found that the T inception is lower than the maximum flame temperature, T max , by ~ 45° and appeared ~ 1 mm further than the location of T max . Using the Lagrangian quantity df v /dt and f v , it was possible to reveal the soot growth rate, k SG . At pressure of 27 kPa, the value of k SG was evaluated as 20 s −1 .
Publisher: IOP Publishing
Date: 31-05-2006
Publisher: The Optical Society
Date: 19-01-2016
DOI: 10.1364/OE.24.001507
Publisher: AIP Publishing
Date: 07-2023
DOI: 10.1063/5.0152865
Abstract: Supervised deep learning methods reported recently have shown promising capability and efficiency in particle image velocimetry (PIV) processes compared to the traditional cross correlation and optical flow methods. However, the deep learning-based methods in previous reports require synthesized particle images and simulated flows for training prior to applications, conflicting with experimental scenarios. To address this crucial limitation, unsupervised deep learning methods have also been proposed for flow velocity reconstruction, but they are generally limited to rough flow reconstructions with low accuracy in velocity due to, for ex le, particle occlusion and out-of-boundary motions. This paper proposes a new unsupervised deep learning model named UnPWCNet-PIV (an unsupervised optical flow network using Pyramid, Warping, and Cost Volume). Such a pyramidical network with specific enhancements on flow reconstructions holds capabilities to manage particle occlusion and boundary motions. The new model showed comparable accuracy and robustness with the advanced supervised deep learning methods, which are based on synthesized images, together with superior performance on experimental images. This paper presents the details of the UnPWCNet-PIV architecture and the assessments of its accuracy and robustness on both synthesized and experimental images.
Publisher: Springer Science and Business Media LLC
Date: 15-01-2021
Publisher: Optica Publishing Group
Date: 10-09-2021
DOI: 10.1364/OE.433785
Abstract: This paper reports an approach to interpolate planar laser-induced fluorescence (PLIF) images of CH 2 O between consecutive experimental data by means of computational imaging realized with convolutional neural network (CNN). Such a deep learning based method can achieve higher temporal resolution for 2D visualization of intermediate species in combustion based on high-speed experimental images. The capability of the model was tested for generating 100 kHz PLIF images by interpolating single and multiple PLIF frames into the sequences of experimental images of lower frequencies (50, 33, 25 and 20 kHz). Results show that the prediction indices, including intersection over union (IoU), peak signal to noise ratio (PSNR), structural similarity index (SSIM), and time averaged correlation coefficient at various axial positions could achieve acceptable accuracy. This work sheds light on the utilization of CNN-based models to achieve optical flow computation and image sequence interpolation, also providing an efficient off-line model as an alternative pathway to overcome the experimental challenges of the state-of-the-art ultra-high speed PLIF techniques, e.g., to further increase repetition rate and save data transfer time.
Publisher: American Chemical Society (ACS)
Date: 17-12-2019
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 2019
Publisher: MDPI AG
Date: 31-05-2023
DOI: 10.3390/FIRE6060222
Abstract: Fire accidents threaten public safety. One of the greatest challenges during fire rescue is that firefighters need to find objects as quickly as possible in an environment with strong flame luminosity and dense smoke. This paper reports an optical method, called violet illumination, coupled with deep learning, to significantly increase the effectiveness in searching for and identifying rescue targets during a fire. With a relatively simple optical system, broadband flame luminosity can be spectrally filtered out from the scattering signal of the object. The application of deep learning algorithms can further and significantly enhance the effectiveness of object search and identification. The work shows that this novel optics–deep learning combined method can improve the object identification accuracy from 7.0% with the naked eye to 83.1%. A processing speed of 10 frames per second can also be achieved on a single CPU. These results indicate that the optical method coupled with machine learning algorithms can potentially be a very useful technique for object searching in fire rescue, especially considering the emergence of low-cost, powerful, compact violet light sources and the rapid development of machine learning methods. Potential designs for practical systems are also discussed.
Publisher: Elsevier BV
Date: 2009
Publisher: Elsevier BV
Date: 06-2010
Publisher: Springer Science and Business Media LLC
Date: 31-03-2021
Publisher: Elsevier BV
Date: 04-2023
Publisher: Public Library of Science (PLoS)
Date: 14-03-2018
Publisher: Elsevier BV
Date: 12-2018
Publisher: Wiley
Date: 02-12-2010
DOI: 10.1002/FAM.1071
Publisher: The Optical Society
Date: 12-11-2015
DOI: 10.1364/OE.23.030414
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 2009
Publisher: Springer Science and Business Media LLC
Date: 13-05-2010
Publisher: Elsevier BV
Date: 04-2016
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 12-2012
Publisher: Elsevier BV
Date: 05-2022
Publisher: Springer Science and Business Media LLC
Date: 17-12-2014
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 2017
Publisher: IOP Publishing
Date: 17-10-2011
Publisher: Elsevier BV
Date: 06-2007
Publisher: Springer Science and Business Media LLC
Date: 2023
Publisher: EDP Sciences
Date: 17-05-2006
Publisher: Elsevier BV
Date: 12-2015
Publisher: American Chemical Society (ACS)
Date: 19-09-2022
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 10-2011
Publisher: Optica Publishing Group
Date: 23-03-2021
DOI: 10.1364/OE.421017
Abstract: We report an optical method for particle velocity measurement that is suitable for the measurement of particle velocities within dense particle-laden flows with high spatial resolution. The technique is based on particle shadow velocimetry with the use of a long-distance microscopic lens for images collection. The narrow depth of field of the lens allows particles within the focal plane to have much higher pattern intensities than those outside it on the collected images. Data processing was then employed to remove particles from outside the focal plane based on the gradient of the signal and a threshold. Following this, particle velocity was calculated from two successive images in the usual way. The technique was successfully demonstrated in a free-falling particle curtain with volume fractions in the four-way coupling regime of near-spherical micro-particles falling under gravity. The method was successfully employed to measure the transverse velocity profile through the curtain, which is the first time that such a measurement has been performed. Other highly-fidelity experimental data, which is also well suited to model development and validation, include the particle mass flow rate, curtain thickness and opacity.
Publisher: Optica Publishing Group
Date: 03-01-2022
DOI: 10.1364/AO.438766
Abstract: We report a relatively simple configuration of laser-induced breakdown spectroscopy (LIBS) that is suitable for gas flow diagnostics with increased spatial resolution, signal intensity, and stability. In this optical configuration, two laser beams are generated by splitting a single laser beam, and then they are focused and crossed orthogonally at the detection volume from two different optical paths. Different from dual-pulse LIBS, this LIBS configuration uses only one laser source, and thus is of relatively low cost. Several advantages were found for this simple beam-crossing LIBS when it was demonstrated in air in the present work, particularly on signal enhancement and stabilization, confining plasma volume, and controlling plasma position. Both of the latter two advantages are relevant to spatial resolution improvement of LIBS in gases, which has rarely been discussed in previous reports. An enhancement factor of 2 was found for atomic hydrogen, nitrogen, and oxygen emissions with respect to conventional LIBS. Another advantage is that the position of breakdown can be precisely controlled through adjustment of the propagation of the two beams, also resulting in smaller plasma volume and stable emission intensity. Furthermore, the technique is moderately tolerant to dust particles neutrally present in the environment, avoiding the spark occurring at a position out of the detection volume. Beyond LIBS, the new configuration has other potential applications, e.g., laser-induced ignition, which is also briefly discussed.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Springer Science and Business Media LLC
Date: 17-02-2005
Publisher: Elsevier BV
Date: 08-2022
Publisher: International Association for Fire Safety Science
Date: 2011
Publisher: Optica Publishing Group
Date: 05-08-2021
DOI: 10.1364/OL.428357
Abstract: In this Letter, we present a particle image/tracking velocimetry (PIV/PTV) technique for simultaneous velocity measurement of both fluid and particle phases, adopting newly developed optical phase discrimination methods and novel optical particles. Spherical acrylic (PMMA) particles of diameter ∼ O ( 100 µ m ) were used as the particle phase, while fine B A M : E u 2 + phosphors of diameter ∼ O ( 1 µ m ) were used as the fluid tracer. Under Nd:YAG 355 nm laser excitation, both the laser-induced fluorescence (LIF) from PMMA and laser-induced phosphorescence (LIP) from B A M : E u 2 + provided sufficiently strong signals for PIV imaging with two non-intensified cameras and were clearly separable for phase discrimination using spectral filters and temporal profiles. The advantages of the PIV/PTV method include the relatively low cost of B A M : E u 2 + phosphors, high sphericity and narrow size distribution of PMMA particles with LIF emission, and direct optical discrimination eliminating artifacts, while requiring much less computational capacity for PIV/PTV processing of complex particle-laden flows.
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 05-2015
Publisher: Springer Science and Business Media LLC
Date: 11-2009
Publisher: Elsevier BV
Date: 07-2017
Publisher: Wiley
Date: 25-03-2011
DOI: 10.1002/JRS.2894
Publisher: ASME International
Date: 05-04-2016
DOI: 10.1115/1.4032943
Abstract: This paper presents assessments of the sensitivity of the performance of high flux solar simulators to the key variables of conical secondary concentrators for metal halide l s, which offer complementary benefits compared with xenon arc l s. The assessment is performed for both a single-l configuration and a seven-l array, each l close-coupled with its own elliptical reflector, and then aligned with a common conical secondary concentrator. The simulation of heat flux from both the single- and the seven-l systems was performed with the Monte Carlo ray-tracing code, which was validated with the experimental results from the single-l system. The calculated heat flux at the focal plane agrees with the measured peak flux to within 5% and to within 13% of the measured half width. Calculated results also show that the addition of the secondary concentrator to the single-l system can increase the peak flux by 294% and the average flux by up to 93% within a target of 100 mm in diameter, with a corresponding reduction in total power by 15%. The conical secondary concentrator is less effective for a seven-l system, increasing the peak and average fluxes by 87.3% and 100%, respectively, within 100 mm diameter focal plane, with a corresponding reduction in total power by 48%. The model was then used to assess the sensitivity of the geometry of the secondary concentrators for both the single- and seven-l systems. The results show that the average heat flux is sensitive to the surface reflectance of the secondary concentrator, with the average flux decreasing almost linearly with the surface reflectance. The presence of the secondary cone greatly reduces the sensitivity of the concentrated heat flux to misalignment of the tilting angle of the elliptical reflector relative to the arc.
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 04-2010
Publisher: Elsevier BV
Date: 2021
Publisher: IOP Publishing
Date: 26-06-2014
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 04-2010
Publisher: Elsevier BV
Date: 08-2018
No related grants have been discovered for Valeria Lencioni.