The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
David G Grier - One of the best experts on this subject based on the ideXlab platform.
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Optimizing the Synthesis of Monodisperse Colloidal Spheres Using Holographic Particle Characterization
Langmuir, 2019Co-Authors: Christine Middleton, Mark Hannel, Andrew D. Hollingsworth, David J. Pine, David G GrierAbstract:Holographic Particle Characterization measures the sizes and compositions of individual colloidal Particles dispersed in fluid media and rapidly amasses statistics on the distributions of these properties, even for complex heterogeneous dispersions. This information is useful for analyzing and optimizing protocols for synthesizing colloidal Particles. We illustrate how holographic Characterization can guide process design through a case study on a particularly versatile model system composed of an aqueous dispersion of micrometer-scale spheres synthesized from the organosilane monomer 3-(trimethoxysilyl)propyl methacrylate.
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Machine-learning approach to holographic Particle Characterization
Optics Express, 2014Co-Authors: Aaron Yevick, Mark Hannel, David G GrierAbstract:Holograms of colloidal dispersions encode comprehensive information about individual Particles’ three-dimensional positions, sizes and optical properties. Extracting that information typically is computationally intensive, and thus slow. Here, we demonstrate that machine-learning techniques based on support vector machines (SVMs) can analyze holographic video microscopy data in real time on low-power computers. The resulting stream of precise Particle-resolved tracking and Characterization data provides unparalleled insights into the composition and dynamics of colloidal dispersions and enables applications ranging from basic research to process control and quality assurance.
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Label-free Molecular Binding Assays using Holographic Video Microscopy
Optics in the Life Sciences, 2011Co-Authors: Fook Chiong Cheong, David G GrierAbstract:Inline holographic video microscopy’s resolution for single Particle Characterization is fine enough to detect avidin coating on biotinylated colloidal surfaces, without requiring staining or fluorescent labeling.
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Automated Particle Characterization using holographic video microscopy
Optics InfoBase Conference Papers, 2009Co-Authors: Fook Chiong Cheong, David G GrierAbstract:With an efficient Particle identification algorithm, combine with hardware acceleration and software optimization; holographic microscopy data can be analysis in near real time with sufficient accuracy to enable unattended holographic tracking and Particle Characterization. ? 2009 OSA.
Andreas Stohl - One of the best experts on this subject based on the ideXlab platform.
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Raman lidar observations of aged Siberian and Canadian forest fire smoke in the free troposphere over Germany in 2003 : Microphysical Particle Characterization
Journal of Geophysical Research, 2005Co-Authors: Detlef Müller, Ina Mattis, Ulla Wandinger, Albert Ansmann, Dietrich Althausen, Andreas StohlAbstract:[1] Dual-wavelength Raman lidar observations were regularly carried out at Leipzig (51.3°N, 12.4°E) from May to August 2003. The measurements showed that Particle backscatter and extinction coefficients in the free troposphere were higher compared to values in 2000–2002. Backward dispersion modeling indicates that intense forest fires that occurred in Siberia and Canada in spring/summer 2003 were the main cause of these free tropospheric haze layers. Measurements on 3 days were selected for an optical and microphysical Particle Characterization of these well-aged Particle plumes. Particle lidar ratios measured at 532 nm wavelength were higher than at 355 nm. This property seems to be a characteristic feature of aged biomass-burning Particles observed over central Germany. Mean Particle Angstrom exponents calculated for the wavelength range from 355 to 532 nm varied from 0 to 1.3. Particle effective radii varied between 0.24 and 0.41 μm. Pollution advected from North America on 25 August 2003, in contrast, was characterized by considerably smaller Particles. Mean effective radii were ≤0.2 μm, and Angstrom exponents were 1.8–2.1. Lidar ratios in that case were lower at 532 nm compared to those at 355 nm. Such signatures are characteristic for anthropogenic Particles. At the moment, however, it cannot be completely ruled out that extremely hot forest fires in western areas of Canada generated comparably small Particles. Except for this specific case the forest fire Particles were considerably larger than what is usually reported from in situ observations of biomass-burning smoke. Possible explanations for this difference could be the kind of burning process, which could generate much larger Particles in the source region, condensation of organic vapors on existing Particles, and coagulation processes during the long transport time of more than a week. Relative humidity measured in these layers was very low. Hygroscopic growth of the Particles therefore seemed to have little influence on the size of the Particles. The forest fire smoke consisted of moderately absorbing material. Real parts of the complex refractive index of the Particles were mostly
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raman lidar observations of aged siberian and canadian forest fire smoke in the free troposphere over germany in 2003 microphysical Particle Characterization
Journal of Geophysical Research, 2005Co-Authors: Detlef Müller, Ina Mattis, Ulla Wandinger, Albert Ansmann, Dietrich Althausen, Andreas StohlAbstract:[1] Dual-wavelength Raman lidar observations were regularly carried out at Leipzig (51.3°N, 12.4°E) from May to August 2003. The measurements showed that Particle backscatter and extinction coefficients in the free troposphere were higher compared to values in 2000–2002. Backward dispersion modeling indicates that intense forest fires that occurred in Siberia and Canada in spring/summer 2003 were the main cause of these free tropospheric haze layers. Measurements on 3 days were selected for an optical and microphysical Particle Characterization of these well-aged Particle plumes. Particle lidar ratios measured at 532 nm wavelength were higher than at 355 nm. This property seems to be a characteristic feature of aged biomass-burning Particles observed over central Germany. Mean Particle Angstrom exponents calculated for the wavelength range from 355 to 532 nm varied from 0 to 1.3. Particle effective radii varied between 0.24 and 0.41 μm. Pollution advected from North America on 25 August 2003, in contrast, was characterized by considerably smaller Particles. Mean effective radii were ≤0.2 μm, and Angstrom exponents were 1.8–2.1. Lidar ratios in that case were lower at 532 nm compared to those at 355 nm. Such signatures are characteristic for anthropogenic Particles. At the moment, however, it cannot be completely ruled out that extremely hot forest fires in western areas of Canada generated comparably small Particles. Except for this specific case the forest fire Particles were considerably larger than what is usually reported from in situ observations of biomass-burning smoke. Possible explanations for this difference could be the kind of burning process, which could generate much larger Particles in the source region, condensation of organic vapors on existing Particles, and coagulation processes during the long transport time of more than a week. Relative humidity measured in these layers was very low. Hygroscopic growth of the Particles therefore seemed to have little influence on the size of the Particles. The forest fire smoke consisted of moderately absorbing material. Real parts of the complex refractive index of the Particles were mostly <1.5, and imaginary parts were <0.01i. Single-scattering albedo in all cases varied between 0.9 and 0.98 at 532 nm.
J. D. Miller - One of the best experts on this subject based on the ideXlab platform.
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X-ray tomography for mineral processing technology – 3D Particle Characterization from mine to mill
Minerals & Metallurgical Processing, 2018Co-Authors: J. D. MillerAbstract:From mine to mill, the 3D Characterization of Particles ranging in size from meters to micrometers is now possible. A brief review of X-ray tomography for mineral processing is given with recent advances considered, such as high-speed scanning and image analysis procedures to describe important Particle properties, including size, shape and composition. Considering these new 3D Characterization tools, applications in mineral processing are discussed for high-resolution X-ray microtomography (HRXMT) laboratory analysis of Particles ranging from 20 mm to 5 µm, with a voxel resolution of about 1 µm, including (1) multiphase Particle Characterization by HRXMT and comparison with scanning electron microscopy (SEM), (2) Particle damage state as a result of blasting/comminution, (3) liberation Characterization to describe expected separation efficiency, (4) exposed grain surface area analysis to explain the flotation of locked Particles, and (5) floc size, shape and water content for polymer-induced flocculation. Finally, applications in mineral processing for plant-site analysis using high-speed X-ray computed tomography (HSXCT) are examined, including, for example, coal washability analysis, the analysis of crusher plant products, and the analysis of pebble phosphate products from central Florida. Scanning rates on the order of 1 kg/min for Particle sizes ranging from 150 mm to 1 mm are possible, with a voxel resolution of about 100 µm. For coarse Particles smaller than 5 to 10 mm, high scanning rates of more than 300 t/h may be possible at a voxel resolution of about 1 mm.
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X-ray tomography for mineral processing technology - 3D Particle Characterization from mine to mill
Minerals & Metallurgical Processing, 2018Co-Authors: J. D. MillerAbstract:From mine to mill, the 3D Characterization of Particles ranging in size from meters to micrometers is now possible. A brief review of X-ray tomography for mineral processing is given with recent advances considered, such as high-speed scanning and image analysis procedures to describe important Particle properties, including size, shape and composition. Considering these new 3D Characterization tools, applications in mineral processing are discussed for high-resolution X-ray microtomography (HRXMT) laboratory analysis of Particles ranging from 20 mm to 5 µm, with a voxel resolution of about 1 µm, including (1) multiphase Particle Characterization by HRXMT and comparison with scanning electron microscopy (SEM), (2) Particle damage state as a result of blasting/comminution, (3) liberation Characterization to describe expected separation efficiency, (4) exposed grain surface area analysis to explain the flotation of locked Particles, and (5) floc size, shape and water content for polymer-induced flocculation. Finally, applications in mineral processing for plant-site analysis using high-speed X-ray computed tomography (HSXCT) are examined, including, for example, coal washability analysis, the analysis of crusher plant products, and the analysis of pebble phosphate products from central Florida. Scanning rates on the order of 1 kg/min for Particle sizes ranging from 150 mm to 1 mm are possible, with a voxel resolution of about 100 µm. For coarse Particles smaller than 5 to 10 mm, high scanning rates of more than 300 t/h may be possible at a voxel resolution of about 1 mm.
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Opportunities for plant-site 3D coarse Particle Characterization with automated high-speed X-ray tomography
Minerals & Metallurgical Processing, 2016Co-Authors: J. D. MillerAbstract:The use of 3D X-ray tomography analysis for plant-site Characterization of coarse Particles at a sampling rate of about 3 kg/min for Particles ranging in size from 150 mm to 1 mm at a voxel resolution of about 150 µm is now possible. This is quite a significant advance in X-ray tomography technology and promises to be useful for plant-site coarse Particle Characterization—size, shape, composition, density, texture, grain exposure and mineral liberation—with a response time of minutes after receiving the sample. This paper discusses applications in the mineral industries, including the coal industry, aggregates industry, metal mining and the processing of industrial minerals.
Renliang Xu - One of the best experts on this subject based on the ideXlab platform.
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light scattering a review of Particle Characterization applications
Particuology, 2015Co-Authors: Renliang XuAbstract:Abstract This review covers the progress of light scattering applications in the field of Particle Characterization in the past decade. The review addresses static light scattering (the measurement of scattering intensities due to light–Particle interaction at various spatial locations), dynamic light scattering (the measurement of scattering due to light–Particle interaction as a function of time), and scattering tracking analysis (the tracking of Particle movement through scattering measurement).
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Particle Characterization: Light Scattering Methods
China Particuology, 2002Co-Authors: Renliang XuAbstract:Particle Characterization is an important component in product research and development, manufacture, and quality control of particulate materials and an important tool in the frontier of sciences, such as in biotechnology and nanotechnology. This book systematically describes one major branch of modern Particle Characterization technology - the light scattering methods. This is the first monograph in Particle science and technology covering the principles, instrumentation, data interpretation, applications, and latest experimental development in laser diffraction, optical Particle counting, photon correlation spectroscopy, and electrophoretic light scattering. In addition, a summary of all major Particle sizing and other Characterization methods, basic statistics and sample preparation techniques used in Particle Characterization, as well as almost 500 latest references are provided. The book is a must for industrial users of light scattering techniques characterizing a variety of particulate systems and for undergraduate or graduate students who want to learn how to use light scattering to study particular materials, in chemical engineering, material sciences, physical chemistry and other related fields.
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Light Scattering - The Background Information
Particle Characterization: Light Scattering Methods, 2002Co-Authors: Renliang XuAbstract:Particle Characterization is an important component in product research and development, manufacture, and quality control of particulate materials and an important tool in the frontier of sciences, such as in biotechnology and nanotechnology. This book systematically describes one major branch of modern Particle Characterization technology - the light scattering methods. This is the first monograph in Particle science and technology covering the principles, instrumentation, data interpretation, applications, and latest experimental development in laser diffraction, optical Particle counting, photon correlation spectroscopy, and electrophoretic light scattering. In addition, a summary of all major Particle sizing and other Characterization methods, basic statistics and sample preparation techniques used in Particle Characterization, as well as almost 500 latest references are provided. The book is a must for industrial users of light scattering techniques characterizing a variety of particulate systems and for undergraduate or graduate students who want to learn how to use light scattering to study particular materials, in chemical engineering, material sciences, physical chemistry and other related fields.
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Particle Characterization light scattering methods
2000Co-Authors: Renliang XuAbstract:Preface. Acknowledgements. 1. Particle Characterization - An Overview. 2. Light Scattering - The Background Information. 3. Laser Diffraction - Sizing from Nanometers to Millimeters. 4. Optical Particle Counting - Counting and Sizing. 5. Photon Correlation Spectroscopy - Submicron Particle Characterization. 6. Electrophoretic Light Scattering - Zeta Potential Measurement. Appendices. Author Index. Subject Index.
Chul-un Ro - One of the best experts on this subject based on the ideXlab platform.
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Single-Particle Characterization of summertime Antarctic aerosols collected at King George Island using quantitative energy-dispersive electron probe X-ray microanalysis and attenuated total reflection Fourier transform-infrared imaging techniques.
Environmental Science & Technology, 2011Co-Authors: Shila Maskey, Hong Geng, Heejin Hwang, Young-chul Song, Young-jun Yoon, Chul-un RoAbstract:Single-Particle Characterization of Antarctic aerosols was performed to investigate the impact of marine biogenic sulfur species on the chemical compositions of sea-salt aerosols in the polar atmosphere. Quantitative energy-dispersive electron probe X-ray microanalysis was used to characterize 2900 individual Particles in 10 sets of aerosol samples collected between March 12 and 16, 2009 at King Sejong Station, a Korean scientific research station located at King George Island in the Antarctic. Two size modes of Particles, i.e., PM2.5–10 and PM1.0–2.5, were analyzed, and four types of Particles were identified, with sulfur-containing sea-salt Particles being the most abundant, followed by genuine sea-salt Particles without sulfur species, iron-containing Particles, and other species including CaCO3/CaMg(CO3)2, organic carbon, and aluminosilicates. When a sulfur-containing sea-salt Particle showed an atomic concentration ratio of sulfur to sodium of >0.083 (seawater ratio), it is regarded as containing non...
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Single‐Particle Characterization of indoor aerosol Particles collected at an underground shopping area in Seoul, Korea
Indoor Air, 2011Co-Authors: Shila Maskey, Hae-jin Jung, Taehee Kang, Chul-un RoAbstract:UNLABELLED: In this study, single-Particle Characterization of aerosol Particles collected at an underground shopping area was performed for the first time. A quantitative single-Particle analytical technique, low-Z Particle electron probe X-ray microanalysis, was used to characterize a total of 7900 individual Particles for eight sets of aerosol samples collected at an underground shopping area in Seoul, Korea. Based on secondary electron images and X-ray spectral data of individual Particles, fourteen Particle types were identified, in which primary soil-derived Particles were the most abundant, followed by carbonaceous, Fe-containing, secondary soil-derived, and secondary sea-salt Particles. Carbonaceous Particles exist in three types: organic carbon, carbon-rich, and CNO-rich. A significant number of textile Particles with chemical composition C, N, and O were encountered in some of the aerosol samples, which were from the textile shops and/or from clothes of passersby. Primary soil-derived Particles showed seasonal variation, with peak values in spring samples, reflecting higher air exchange between indoor and outdoor environments in the spring. Secondary soil-derived, secondary sea-salt, and ammonium sulfate Particles were frequently encountered in winter samples. Fe-containing Particles, contributed from a nearby subway station, were in the range of about 19% relative abundances for all samples. PRACTICAL IMPLICATIONS: In underground shopping areas, particulate matters can be a considerable health hazard to the workers, shoppers, passersby, and shop-keepers as they spend their considerable time in this closed microenvironment. However, no study on the characteristics of indoor aerosols in an underground shopping area has been reported to our knowledge. This work provides detailed information on characteristics of underground shopping area aerosols on a single Particle level.
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Single-Particle Characterization of summertime arctic aerosols collected at Ny-Alesund, Svalbard.
Environmental Science & Technology, 2010Co-Authors: Hong Geng, Hae-jin Jung, Hyeok Chung, Chul-un RoAbstract:Single-Particle Characterization of summertime Arctic aerosols is useful to understand the impact of air pollutants on the polar atmosphere. In the present study, a quantitative single Particle analytical technique, low-Z Particle electron probe X-ray microanalysis, was used to characterize 8100 individual Particles overall in 16 sets of aerosol samples collected at Ny-Alesund, Svalbard, Norway on 25−31 July, 2007. Based on their X-ray spectral and secondary electron image data of individual Particles, 13 Particle types were identified, in which Particles of marine origin were the most abundant, followed by carbonaceous and mineral dust Particles. A number of aged (reacted) sea salt (and mixture) Particles produced by the atmospheric reaction of genuine sea-salts, especially with NOx or HNO3, were significantly encountered in almost all the aerosol samples. They greatly outnumbered genuine sea salt Particles, implying that the summertime Arctic atmosphere, generally regarded as a clean background environm...
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The influence of collecting substrates on the single-Particle Characterization of real atmospheric aerosols
Analytica Chimica Acta, 2009Co-Authors: Shila Maskey, M. Choël, Sunni Kang, Heejin Hwang, Chul-un RoAbstract:This work investigated the influence of three different collecting substrate materials, Ag and Al foils and grids for transmission electron microscopy (TEM grid), on the morphological and chemical compositional analysis of individual Particles collected at an underground shopping area in Seoul, Korea. The feasibility of using each substrate in a quantitative single-Particle analysis was evaluated by comparing Particle morphologies, X-ray spectra, and elemental quantification results obtained for the three substrates. The morphologies and the quality of X-ray spectra for crystalline mineral Particles were very similar among the three substrates. However, water-soluble, CNO-rich aerosols showed different morphologies among the three substrates, mainly due to the differences in the hygroscopic properties of the substrates. The quality of the X-ray spectra of the CNO-rich Particles was optimal when collected on the TEM grid. To reliably assess the characteristic X-rays of the CNO-rich Particles collected on the Ag and Al foils, appropriate data analysis had to be applied. Especially, the X-ray spectra of the CNO-rich Particles collected on Al foil required a new background subtraction procedure. The overall relative abundances of the chemical species, obtained from the three collecting substrates, were in good agreement with each other and single-Particle Characterization of the real aerosol sample was feasible on the different substrates. However, the TEM grid substrate was the most appropriate for single-Particle analysis of the water-soluble CNO-rich Particles as: (i) it retains the original morphology and size of the Particles, (ii) it allows high contrast in the backscattered electron image (BSEI) mode, and (iii) it provides a high peak-to-background ratio (P/B) with small and correctable interferences in the X-ray spectra.
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Single-Particle Characterization of aerosol samples collected before and during an Asian dust storm in Chuncheon, Korea
Atmospheric Environment, 2008Co-Authors: Heejin Hwang, Chul-un RoAbstract:Low-Z Particle electron probe X-ray microanalysis, a single-Particle analysis method, was used to characterize aerosol samples collected in Chuncheon, Korea, before and during a dust storm that occurred between 10 and 12 March, 2004. Four different samples were analyzed: just before the storm, peak time of the storm, late stage of the storm, and end of the storm. All four of the samples were found to have experienced chemical modifications during long-range transport due to elevated levels of nitrate and sulfate that resulted from atmospheric reactions with CaCO3 and sea-salt Particles. The sample collected just before the storm underwent the most extensive chemical modification during transport. For this particular sample, the overall relative abundances of reacted CaCO3 and sea-salt Particles were 9.8% and 44.2%, respectively. The sample collected at the peak time of the storm also experienced extensive chemical modification with overall relative abundances of reacted CaCO3 and sea-salt Particles at 4.3% and 23.3%, respectively. The backward trajectory analysis for this particular sample revealed two different types of air-masses arriving at the sampling site in Korea; one is high-altitude air-masses moving rapidly and carrying Asian dust Particles and the other a slow-moving low-altitude air-mass from eastern China coastal areas. The single-Particle Characterization of this same sample showed that the Asian dust Particles were mixed with sea-salts entrained over the Yellow Sea, as well as air pollutants from the eastern China coastal areas. However, as the Asian dust storm continued, soil-derived mineral Particles became dominant in the samples that were collected at the late stage of the storm and at the end. For this specific Asian dust storm, the mixing of sea-salts and pollution with Asian dust Particles was observed to occur just at the early stage of the storm.
