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Depth-of-field model for size measurement using a borescope imaging technique under high object concentrations / Md. Iqbal Hossain in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5824–5830 Titre : Depth-of-field model for size measurement using a borescope imaging technique under high object concentrations Type de document : texte imprimé Auteurs : Md. Iqbal Hossain, Auteur ; Yanhui Yang, Auteur ; Armando Borgna, Auteur Année de publication : 2011 Article en page(s) : pp. 5824–5830 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Borescope  imaging Résumé : The direct imaging technique has been a common technique for size distribution measurement in multiphase systems. A statistical reconstruction method was developed in a previous study to determine the actual size distribution from image size measurements. The method accounts for the change in magnification scale within the depth-of-field (DOF) of the imaging device. It is anticipated that the DOF will reduce at high object concentrations. Since accurate DOF information is necessary for the application of the reconstruction method, the effect of object concentration on the DOF is examined in this study. A DOF model is developed to predict the DOF under various object concentrations. The applicability of the DOF model in the statistical reconstruction method is verified experimentally. A theoretical analysis is also performed to discuss the effect of having objects whose image sizes are larger than the maximum viewable limit of the imaging device. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102478q [article] Depth-of-field model for size measurement using a borescope imaging technique under high object concentrations [texte imprimé] / Md. Iqbal Hossain, Auteur ; Yanhui Yang, Auteur ; Armando Borgna, Auteur . - 2011 . - pp. 5824–5830. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5824–5830 Mots-clés : Borescope  imaging Résumé : The direct imaging technique has been a common technique for size distribution measurement in multiphase systems. A statistical reconstruction method was developed in a previous study to determine the actual size distribution from image size measurements. The method accounts for the change in magnification scale within the depth-of-field (DOF) of the imaging device. It is anticipated that the DOF will reduce at high object concentrations. Since accurate DOF information is necessary for the application of the reconstruction method, the effect of object concentration on the DOF is examined in this study. A DOF model is developed to predict the DOF under various object concentrations. The applicability of the DOF model in the statistical reconstruction method is verified experimentally. A theoretical analysis is also performed to discuss the effect of having objects whose image sizes are larger than the maximum viewable limit of the imaging device. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102478q

Determination of actual object size distribution from direct imaging / Md. Iqbal Hossain in Industrial & engineering chemistry research, Vol. 48 N° 22 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10136–10146 Titre : Determination of actual object size distribution from direct imaging Type de document : texte imprimé Auteurs : Md. Iqbal Hossain, Auteur ; Tao Chen, Auteur ; Yanhui Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 10136–10146 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Direct  imaging  Dynamic  system Résumé : Direct imaging is a technique commonly used in the study of particle, bubble, and droplet size distribution in a dynamic system. Objects such as particles, bubbles, and droplets can be present at various distances from the imaging device when images are captured. Hence, the location of the object will need to be known in order to determine the actual size of an individual object. However, the location of the object cannot be determined from a single image. A single calibration scale defined at the focusing plane is normally used for the determination of all the object sizes from images. When the focus is close to the imaging device, the change in magnification with location is large. The size distribution obtained from the use of a single calibration scale would thus give a considerable deviation from the actual size distribution. In this study, a statistical method is proposed to reconstruct the actual object size distribution from the experimental object size distribution obtained from images using a single calibration scale defined at the focusing plane. Experiments are performed to validate the accuracy of the proposed method on the particle size distribution determination in a settling system. The stability of the proposed method is also analyzed theoretically for imaging devices with different depth-of-field (DOF), focusing location, and change in magnification with distance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900857m [article] Determination of actual object size distribution from direct imaging [texte imprimé] / Md. Iqbal Hossain, Auteur ; Tao Chen, Auteur ; Yanhui Yang, Auteur . - 2010 . - pp. 10136–10146. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10136–10146 Mots-clés : Direct  imaging  Dynamic  system Résumé : Direct imaging is a technique commonly used in the study of particle, bubble, and droplet size distribution in a dynamic system. Objects such as particles, bubbles, and droplets can be present at various distances from the imaging device when images are captured. Hence, the location of the object will need to be known in order to determine the actual size of an individual object. However, the location of the object cannot be determined from a single image. A single calibration scale defined at the focusing plane is normally used for the determination of all the object sizes from images. When the focus is close to the imaging device, the change in magnification with location is large. The size distribution obtained from the use of a single calibration scale would thus give a considerable deviation from the actual size distribution. In this study, a statistical method is proposed to reconstruct the actual object size distribution from the experimental object size distribution obtained from images using a single calibration scale defined at the focusing plane. Experiments are performed to validate the accuracy of the proposed method on the particle size distribution determination in a settling system. The stability of the proposed method is also analyzed theoretically for imaging devices with different depth-of-field (DOF), focusing location, and change in magnification with distance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900857m

Study of liquid weeping at a tapered orifice in a bubble column reactor by a computer-aided image analysis algorithm / Md. Iqbal Hossain in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3840–3848 Titre : Study of liquid weeping at a tapered orifice in a bubble column reactor by a computer-aided image analysis algorithm Type de document : texte imprimé Auteurs : Md. Iqbal Hossain, Auteur ; Si Qi Pang, Auteur ; Qing Xi Pang, Auteur Année de publication : 2010 Article en page(s) : pp. 3840–3848 Langues : Anglais (eng) Mots-clés : Liquid  Weeping  Algorithm Résumé : Understanding the phenomenon of liquid weeping requires knowledge of the bubbling and weeping cycle. Hence, an image analysis algorithm is developed and subsequently coupled with high-speed imaging techniques to examine the different stages in the bubbling and weeping cycle automatically. The bubbling and weeping cycle is studied under various operating conditions, using the developed algorithm, coupled with high-speed imaging techniques and the pressure fluctuation measurement. The effect of orifice angle (where the orifice angle is a measure of the orifice taperness) on the liquid weeping rate is evaluated over a range of superficial orifice gas velocities and justified with the aid of the developed algorithm, coupled with high-speed imaging techniques. A gas distributor plate with negative angle orifices is recommended for improved operation of industrial bubble column reactors over the range of superficial orifice gas velocities considered in this study, because it substantially decreases the liquid weeping rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901516f [article] Study of liquid weeping at a tapered orifice in a bubble column reactor by a computer-aided image analysis algorithm [texte imprimé] / Md. Iqbal Hossain, Auteur ; Si Qi Pang, Auteur ; Qing Xi Pang, Auteur . - 2010 . - pp. 3840–3848. Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3840–3848 Mots-clés : Liquid  Weeping  Algorithm Résumé : Understanding the phenomenon of liquid weeping requires knowledge of the bubbling and weeping cycle. Hence, an image analysis algorithm is developed and subsequently coupled with high-speed imaging techniques to examine the different stages in the bubbling and weeping cycle automatically. The bubbling and weeping cycle is studied under various operating conditions, using the developed algorithm, coupled with high-speed imaging techniques and the pressure fluctuation measurement. The effect of orifice angle (where the orifice angle is a measure of the orifice taperness) on the liquid weeping rate is evaluated over a range of superficial orifice gas velocities and justified with the aid of the developed algorithm, coupled with high-speed imaging techniques. A gas distributor plate with negative angle orifices is recommended for improved operation of industrial bubble column reactors over the range of superficial orifice gas velocities considered in this study, because it substantially decreases the liquid weeping rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901516f