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Littérature scientifique sur le sujet « Submicronic particles »

Auteur : Grafiati
Publié le 17 mai 2025

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Articles de revues sur le sujet "Submicronic particles"

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Turysbekov, Dulatbek, Nesipbai Tussupbayev, Bakdaulet Kenzhaliev, Sabira Narbekova et Larissa Semushkina. « The Effect of Novel Submicronic Solid Activators on Sphalerite Flotability ». Minerals 14, no 3 (27 février 2024) : 243. http://dx.doi.org/10.3390/min14030243.

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In this study, we examine the effect of novel submicronic activators made from copper minerals and copper-rich concentrate on sphalerite flotability. The copper minerals and copper concentrate are ground in a vibratory micromill and ultrasonically treated to obtain submicronic sphalerite activators. Histograms show that the concentration of copper particles in the activator after treatment is 92%–94%, with particle sizes of 105–115 nm. The results concerning monomineral flotation showed that sphalerite flotation is possible with the use of submicronic copper particles as an activator. At the same time, the consumption of mineral copper is much lower (by 10 times) than that of copper sulfate. The best results are achieved when submicronic particles of covellite and bornite (with a 60% concentration of particles 300–500 nm in size) were used. Sphalerite recovery amounted to 80%, which is higher than the recovery obtained with the use of copper sulfate by 2% but is 2% lower compared to the use of copper oxyhydroxide. The flotation effect of the submicronic activators on sphalerite was tested in laboratory conditions using polymetallic ore from one of Kazakhstan’s deposits. It is shown that the novel submicron activators based on bornite and copper concentrate exhibit much lower consumption rates and can replace the more expensive copper sulfate at the same Zn content (54.8%–54.9%), obtaining recovery rates of 95.69%–96.57%.
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Afanou, Komlavi Anani, Anne Straumfors, Asbjørn Skogstad, Terje Nilsen, Ole Synnes, Ida Skaar, Linda Hjeljord, Arne Tronsmo, Brett James Green et Wijnand Eduard. « Submicronic Fungal Bioaerosols : High-Resolution Microscopic Characterization and Quantification ». Applied and Environmental Microbiology 80, no 22 (12 septembre 2014) : 7122–30. http://dx.doi.org/10.1128/aem.01740-14.

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ABSTRACTSubmicronic particles released from fungal cultures have been suggested to be additional sources of personal exposure in mold-contaminated buildings.In vitrogeneration of these particles has been studied with particle counters, eventually supplemented by autofluorescence, that recognize fragments by size and discriminate biotic from abiotic particles. However, the fungal origin of submicronic particles remains unclear. In this study, submicronic fungal particles derived fromAspergillus fumigatus,A. versicolor, andPenicillium chrysogenumcultures grown on agar and gypsum board were aerosolized and enumerated using field emission scanning electron microscopy (FESEM). A novel bioaerosol generator and a fungal spores source strength tester were compared at 12 and 20 liters min−1airflow. The overall median numbers of aerosolized submicronic particles were 2 × 105cm−2, 2.6 × 103cm−2, and 0.9 × 103cm−2forA. fumigatus,A. versicolor, andP. chrysogenum, respectively.A. fumigatusreleased significantly (P< 0.001) more particles thanA. versicolorandP. chrysogenum. The ratios of submicronic fragments to larger particles, regardless of media type, were 1:3, 5:1, and 1:2 forA. fumigatus,A. versicolor, andP. chrysogenum, respectively. Spore fragments identified by the presence of rodlets amounted to 13%, 2%, and 0% of the submicronic particles released fromA. fumigatus,A. versicolor, andP. chrysogenum, respectively. Submicronic particles with and without rodlets were also aerosolized from cultures grown on cellophane-covered media, indirectly confirming their fungal origin. Both hyphae and conidia could fragment into submicronic particles and aerosolizein vitro. These findings further highlight the potential contribution of fungal fragments to personal fungal exposure.
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Reverchon, E., C. Celano, G. Della Porta, A. Di Trolio et S. Pace. « Supercritical antisolvent precipitation : A new technique for preparing submicronic yttrium powders to improve YBCO superconductors ». Journal of Materials Research 13, no 2 (février 1998) : 284–89. http://dx.doi.org/10.1557/jmr.1998.0039.

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The solvent, supercritical antisolvent technique (SAS) has been used to produce submicronic particles of yttrium acetate for the synthesis of YBCO superconductors. For this purpose, in a continuous SAS apparatus dimethylsulfoxide (DMSO) as yttrium acetate solvent and supercritical carbon dioxide as antisolvent have been adopted. Experiments have been performed in the pressure range between 70 and 160 bar and for temperatures between 40 and 70 °C. Different concentrations of yttrium acetate in DMSO have also been tested. Various morphologies of yttrium acetate particles have been obtained, having mean particle diameters from 0.1 to 7 μm. At 40 °C and pressures larger than 120 bar, submicronic spherical particles of yttrium acetate of about 0.1 μm diameter and with a narrow particle size distribution have been achieved.
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Danciulescu, Valeriu, Andreea Cozea, Elena Bucur, Gheorghita Tanase et Mihai Bratu. « Concentration versus number of particles in the assessment of air pollution with particulate matters ». Romanian Journal of Ecology & ; Environmental Chemistry 4, no 1 (30 juin 2022) : 68–74. http://dx.doi.org/10.21698/rjeec.2022.107.

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In this paper, an assessment study was performed regarding air pollution with particulate matters including submicron particles. The evaluation of the contamination level was performed at a textile production unit in Pascani, Romania, which produces polyester knitwear. In the study, automatic determinations of total suspended particulate matters (TSP), PM 10, PM 2.5, and PM 1 (particle with nominal diameter <10 µm, <2.5 µm, and <1 µm), and submicron particulate matters (0.25, 0.35, 0.50 and 0.70) were performed both outdoor, in the ambient air, and indoor (workplace) in the area of the knitting machines. The correlation between the mass concentrations of submicronic particles (µg/m 3) and the numerical concentrations (number of particles/m3) was studied, too, to establish the most appropriate expression of the air pollution level with particulate matter. The results of the performed tests showed a level of ambient air pollution with particulate matters that exceed the limit values in the case of PM 2.5 and PM 10, the total suspended particulates still falling within the limits established by law. Likewise, in the case of workplace air, the level of inhalable particulate matter (particles with nominal diameter <100 µm), the concentration is below the limit values. Regarding the way of expressing the concentration of air particles, in µg/m3 or in no. particles/m3 the tests indicated better representativeness of the pollution level if the concentration in µg m3 is expressed for the dimensional fractions with diameter ≥ 1 µm and in no. particles/m3 for particles with a diameter of ≤1 µm.
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Buron, M. P., M. Gougeon et A. Rousset. « Magnetic Behaviour of Submicronic Acicular Composite Particles ». Key Engineering Materials 132-136 (avril 1997) : 1420–23. http://dx.doi.org/10.4028/www.scientific.net/kem.132-136.1420.

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Pessey, Vincent, Rosa Garriga, Francois Weill, Bernard Chevalier, Jean Etourneau et François Cansell. « Submicronic particles synthesis by a supercritical way ». High Pressure Research 20, no 1-6 (mai 2001) : 289–98. http://dx.doi.org/10.1080/08957950108206176.

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Afanou, Komlavi Anani, Anne Straumfors, Asbjørn Skogstad, Ajay P. Nayak, Ida Skaar, Linda Hjeljord, Arne Tronsmo, Wijnand Eduard et Brett James Green. « Indirect Immunodetection of Fungal Fragments by Field Emission Scanning Electron Microscopy ». Applied and Environmental Microbiology 81, no 17 (19 juin 2015) : 5794–803. http://dx.doi.org/10.1128/aem.00929-15.

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ABSTRACTSubmicronic fungal fragments have been observed inin vitroaerosolization experiments. The occurrence of these particles has therefore been suggested to contribute to respiratory health problems observed in mold-contaminated indoor environments. However, the role of submicronic fragments in exacerbating adverse health effects has remained unclear due to limitations associated with detection methods. In the present study, we report the development of an indirect immunodetection assay that utilizes chicken polyclonal antibodies developed against spores fromAspergillus versicolorand high-resolution field emission scanning electron microscopy (FESEM). Immunolabeling was performed withA. versicolorfragments immobilized and fixed onto poly-l-lysine-coated polycarbonate filters. Ninety percent of submicronic fragments and 1- to 2-μm fragments, compared to 100% of >2-μm fragments generated from pure freeze-dried mycelial fragments ofA. versicolor, were positively labeled. In proof-of-concept experiments, air samples collected from moldy indoor environments were evaluated using the immunolabeling technique. Our results indicated that 13% of the total collected particles were derived from fungi. This fraction comprises 79% of the fragments that were detected by immunolabeling and 21% of the spore particles that were morphologically identified. The methods reported in this study enable the enumeration of fungal particles, including submicronic fragments, in a complex heterogeneous environmental sample.
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Andrade, Bárbara K. S. A., Rafael Sartim et Mônica L. Aguiar. « Precoating Effects in Fine Steelmaking Dust Filtration ». Atmosphere 13, no 10 (13 octobre 2022) : 1669. http://dx.doi.org/10.3390/atmos13101669.

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Particle emissions into the atmosphere can cause extensive damage to the environment and human health. To improve the efficiency in the collection of submicronic particles, new filtration media appeared on the market due to new textile technologies and equipment, such as filter media developed with polytetrafluoroethylene (PTFE) membranes; however, these are more expensive. A filter coating technique called precoating is a more economical alternative that could enhance filtration efficiency. This paper aimed to evaluate the operational parameters of precoating for micro- and nanoparticle filtration and compare the results with those obtained from the PTFE membrane. For this purpose, filtration cycles were performed, using precoated polyester with hydrated lime and dolomitic limestone, polyester with a PTFE membrane, and steel industry ultrafine dust. The results showed that the precoated polyester had a longer cycle duration and lower pressure drop than the polyester with a PTFE membrane. Therefore, precoating was shown to be a great alternative to be used in bag filters in steel mills because it presented high collection efficiency for submicronic particles, in addition to increasing the bag lifespan with less energy expenditure.
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Contreras, Carola, Fernanda Isquierdo, Pedro Pereira-Almao et Carlos E. Scott. « Effect of Particle Size on the HDS Activity of Molybdenum Sulfide ». Journal of Nanotechnology 2016 (2016) : 1–9. http://dx.doi.org/10.1155/2016/3752484.

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More than half of the total world oil reserves are heavy oil, extra heavy oil, and bitumen; however their catalytic conversion to more valuable products is challenging. The use of submicronic particles or nanoparticles of catalysts suspended in the feedstock may be a viable alternative to the conversion of heavy oils at refinery level or downhole (in situ upgrading). In the present work, molybdenum sulfide (MoS2) particles with varying diameters (10000–10 nm) were prepared using polyvinylpyrrolidone as capping agent. The prepared particles were characterized by DLS, TEM, XRD, and XPS and tested in the hydrodesulfurization (HDS) of a vacuum gas oil (VGO). A correlation between particle size and activity is presented. It was found that particles with diameters around 13 nm show double the HDS activity compared with the material with micrometric particle sizes (diameter ≈ 10,000 nm).
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Hoyos, Angela, Aurélie Joubert, Ala Bouhanguel, Marc Henry, Sylvain Durécu et Laurence Le Coq. « Multiapproach Design Methodology of a Downscaled Wet Scrubber to Study the Collection of Submicronic Particles from Waste Incineration Flue Gas ». Processes 12, no 8 (7 août 2024) : 1655. http://dx.doi.org/10.3390/pr12081655.

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Wet scrubbers are traditionally used as dedusting systems in waste incineration plants for wet flue gas treatment. Although these devices are not particularly performant at capturing submicron particles, which are associated with health and environmental hazards, their collection efficiency can be improved by optimizing operating conditions. This study presents the design methodology of a downscaled wet scrubber, constructed and implemented at a municipal waste incineration plant to be fed with real fumes, and to study its efficiency towards the removal of submicronic particles. The downscaled scrubber was designed to operate with flue gas at 200 °C, high humidity (1% RH), and an average total particle concentration of 200 mg/Nm3. A criterion of geometric, aerodynamic, and residence time similarities to an existing industrial scrubber was targeted. The height of the device was selected by matching the theoretical fractional particle collection efficiencies of the industrial and downscaled scrubbers. Featuring a cylindrical shape, the downscaled scrubber has a diameter of 0.3 m and a height of 2.5 m. It operates in co-current with water injected through four spray levels. Computational fluid dynamics simulations were conducted to analyze the gas flow structure within the device, and the results were validated by hot wire anemometer velocity measurements.
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Thèses sur le sujet "Submicronic particles"

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Boskovic, Lucija. « Influence of Submicron Particle Shape on Behaviour during Filtration and Separation Processes ». Thesis, Griffith University, 2008. http://hdl.handle.net/10072/366111.

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Filtration is the most efficient method of aerosol monitoring and control. A number of theories (Bradley, 1932); (Hamaker, 1937); (Johnson et al., 1971); (Wang and Kasper, 1991); (Dahneke, 1995); (Wall et al., 1990) have been developed to describe the particle interaction with surface of a filter and to estimate the probability of the particle adhesion onto a surface. A range of the particle, filter and process parameters could contribute to the strength of the adhesion. Some of them are: hardness and cross-sectional shape of the fiber, smoothness of either the fiber or particle, air humidity, the effect of particle shape and many others. Obviously, the particle size (and correspondingly the surface area) also plays a crucial role in the bouncing processes. However, despite its importance in the research field the detailed mechanisms of the particle-fiber collision and possibility for the particle to bounce or to be re-entrained have not been fully explored. Therefore, there is a need for a theoretical and experimental knowledge concerning the influence of particle bouncing on filtration and separation processes. Although, some work on the effect of particle shape on filtration process has been done, there is still need for further research regarding the influence of motion of the particles of different shape along a fiber...
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Engineering
Science, Environment, Engineering and Technology
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Hoyos, Velasquez Angela Maria. « Performance d’une colonne de lavage vis-à-vis des particules de fumées d’incinération : étude expérimentale au sein d’une usine d’incinération ». Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2025. http://www.theses.fr/2025IMTA0460.

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Parmi les dispositifs de traitement des fumées les plus utilisés, figurent les laveurs à pulvérisation. Bien qu'efficaces pour absorber des gaz acides, les laveurs à pulvérisation ne sont pas conçus pour capturer les particules submicroniques. Toutefois, des études en laboratoire ont montré qu'il est possible de collecter davantage de particules fines en ajustant leurs conditions opératoires. Dans cette thèse, la performance de collecte des particules par les laveurs à pulvérisation a été évaluée dans des conditions réelles d’une usine d’incinération de déchets à deux échelles : (i) en exploitant un laveur à échelle réduite alimenté par des fumées réelles de l’incinération de déchets ménagers, et (ii) en quantifiant l'efficacité de collecte des particules d’un laveur industriel d’un site d’incinération de déchets dangereux. Des simulations numériques CFD ont été réalisées pour dimensionner le dispositif à échelle réduite et analyser l'écoulement à l'intérieur des laveurs. Une étude paramétrique a été conduite pour étudier l'influence des conditions opératoires sur les performances du laveur à échelle réduite. Les résultats indiquent que la réduction du diamètre des gouttelettes et la hausse du rapport entre les débits liquide/gaz améliorent la collecte des particules de toute taille. Aucune influence du temps de séjour du gaz n'a été constatée. Les modèles mécanistiques de collecte testés surestiment les résultats dans les conditions réelles d’exploitation. Les performances de collecte des particules du laveur industriel se sont avérées quasi nulles/négatives, en raison de phénomènes réactionnels et de transferts entre les gouttelettes, les gaz et les particules
Wet scrubbers are among the most used industrial flue gas treatment devices. Although effective at absorbing acidic gases, wet scrubbers are not designed to capture submicronic particles. However, laboratory studies have shown that it is possible to improve their fine particle collection efficiency by adjusting operating conditions. In this thesis, the performance of wet scrubbers for collecting particles was evaluated under real conditions of a waste incineration plant at two scales: (i) by operating a downscaled wet scrubber fed with real flue gases from the incineration of household waste, and (ii) by quantifying the particle collection efficiency of an industrial scrubber at a hazardous waste incineration plant. CFD numerical simulations were performed to design the downscaled system and analyze the flow patterns inside the scrubbers. A parametric study was conducted to investigate the influence of operating conditions on the performance of the downscaled scrubber. The results showed that reducing the droplet diameter and increasing the liquid/gas flow ratio improved particle collection across all sizes. No influence of gas residence time was observed. The mechanistic collection models tested overestimate the results under real operating conditions. The performance of the industrial scrubber for collecting particles was found to be nearly zero/negative due to reaction and transfer phenomena between the droplets, the gases, and the particles
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Boudhan, Rachid. « Performance of pulse-jet bag filter regarding particle removal for nano-waste incineration conditions ». Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0022/document.

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Les performances de filtration d’un filtre à manche vis-à-vis de particules submicroniques et nanométriques ont été évaluées à l’échelle du laboratoire durant plusieurs cycles de colmatage/décolmatage. La distribution granulométrique des particules (aérosol de combustion) était représentative de celle rencontrée en incinération de nano-déchets en sortie de chambre de combustion à l’échelle du laboratoire. Le filtre à manche opérait en conditions réalistes, représentatives de celles rencontrées dans les lignes de traitement des fumées d’incinération de déchets en termes de température, humidité, vitesse de filtration, présence de réactifs et conditions de décolmatage. Le flux d’air et le filtre à manche étaient chauffés à 150°C, la teneur en eau était de 10-12% (soit 3% d’humidité relative HR), et la vitesse de filtration était fixée à 1,9 cm.s⁻¹. Un mélange de particules de taille submicronique de charbon actif et de bicarbonate de sodium, utilisées dans les lignes de traitement des fumées d’incinération pour l’abattement des dioxines/furanes et des gaz acides, était généré simultanément avec l’aérosol de combustion. L’étude s’est centrée sur les performances de filtration au début de la durée de vie du filtre à manche, avant stabilisation de la perte de charge résiduelle du filtre résultant des précédents cycles de filtration. La perte de charge maximale du filtre était fixée à 150 Pa pour tous les cycles de filtration avant décolmatage par rétro-soufflage à air comprimé. Les performances du filtre à manche ont été évaluées en termes d’évolution de sa perte de charge et de son efficacité de collecte (totale et fractionnelle) au cours des cycles de colmatage/décolmatage. De plus, des études expérimentales et théoriques ont été menées afin d’étudier l’influence de divers paramètres sur les performances de filtration du filtre en configuration manche ou plane, tels que l’humidité de l’air (3% HR versus 0% HR à 150°C), la température (150°C versus 24°C), la vitesse de filtration (1,9 cm.s⁻¹ versus 1,4 cm.s⁻¹) et l’influence de l’injection de réactifs. Les principaux résultats de cette étude sont : (i) importante efficacité de capture des particules du filtre à manche en conditions représentatives des lignes de traitement des fumées d’incinération : efficacité minimale de collecte de 98,5% mesurée pour des particules de taille 74 ± 15 nm (diamètre de mobilité électrique), (ii) influence du gâteau résiduel de particules au début de chaque cycle de filtration sur les performances de traitement, (iii) influence significative de l’humidité de l’air sur la structure du gâteau de particules probablement due à l’augmentation des forces d’adhésion entre les particules en présence d’humidité (150°C – 3% HR soit environ 100 g d’eau par kg d’air sec) ; augmentation plus rapide de la perte de charge du filtre à manche en présence d’humidité (150°C – 3% HR) qu’en conditions d’air sec (150°C – 0% HR)
Filtration performance of a pulse-jet bag filter was evaluated at the laboratory-scale regarding submicronic particles with a nanosized fraction during clogging/unclogging cycles. The particle size distribution was representative to those encountered at the outlet of a nano-waste incineration device at laboratory-scale. The bag filter was operated in conditions as similar as possible to those found in flue gas treatment of waste incineration plants, in terms of temperature, humidity, filtration velocity, injection of sorbent reagents and unclogging conditions. The air flow and the bag filter were heated to 150°C, the water content was maintained in the air flow in the range of 10-12% (3% of relative humidity RH), and filtration velocity throughout the bag filter was fixed at 1.9 cm.s⁻¹. A mixture of submicronic suspended particles of activated carbon and sodium bicarbonate, both used in flue gas treatment systems mainly for the removal of dioxins/furans and acid gases, was generated simultaneously with the aerosol representative of combustion emissions.The study focused on the filtration performance at the beginning of the bag filter’s lifetime filter for the 11 first clogging-unclogging cycles before stabilizing the residual pressure drop reached after pulse-jet unclogging. The maximum pressure drop was set at 150 Pa for all filtration cycles. Once the maximum pressure drop was reached, the filter was unclogged using the pulse-jet system. The performance of the bag filter was evaluated in terms of the evolution of pressure drop, fractional and total particle collection efficiencies, during the clogging/unclogging cycles.Moreover, an experimental and theoretical study was carried out on the influence of different parameters on the filtration performance of bag filter and flat filter, such as influence of humidity (3% RH versus 0% RH at 150°C), temperature (150°C versus 24°C), filtration velocity (1.9 cm.s⁻¹ versus 1.4 cm.s⁻¹) and the influence of the injection of sorbent reagents.The main results of this study are: (i) high collection efficiency of the bag filter in representative conditions of flue gas treatment of waste incineration: minimun particle collection efficiency of 98.5% for particle diameter of 74 ± 15 nm (electrical mobility diameter), (ii) influence of residual particle cake at the beginning of the filtration cycles on the bag filter performance, (iii) significant influence of humidity on the porosity of the particle cake due to the capillary condensation of water between the particles in presence of humidity (150°C - 3% RH i.e. almost 100 g of water per kg of dry air). Faster increase of bag filter pressure drop in presence of humidiy (150°C - 3% RH) as compared to the dry conditions (150°C - 0% RH)
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Garcia-Lopez, Alicia. « Hybrid model for characterization of submicron particles using multiwavelength spectroscopy ». Scholar Commons, 2005. http://scholarcommons.usf.edu/etd/2889.

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The area of particle characterization is expansive; it contains many technologies and methods of analysis. Light spectroscopy techniques yield information on the joint property distribution of particles, comprising the chemical composition, size, shape, and orientation of the particles. The objective of this dissertation is to develop a hybrid scattering-absorption model incorporating Mie and Rayleigh-Debye-Gans theory to characterize submicron particles in suspension with multiwavelength spectroscopy.Rayleigh-Debye-Gans theory (RDG) was chosen as a model to relate the particles joint property distribution to the light scattering and absorption phenomena for submicron particles. A correction model to instrument parameters of relevance was implemented to Rayleigh-Debye-Gans theory for spheres. Behavior of nonspherical particles using RDG theory was compared with Mie theory (as a reference). A multiwavelength assessment of Rayleigh-Debye-Gans theory for spheres was conducted where strict adherence to the limits could not be followed. Reported corrections to the refractive indices were implemented to RDG to try and achieve Mies spectral prediction for spheres.The results of studies conducted for RDG concluded the following. The angle of acceptance plays an important role in being able to assess and interpret spectral differences. Multiwavelength transmission spectra contains qualitative information on shape and orientation of non-spherical particles, and it should be possible to extract this information from carefully measured spectra. There is disagreement between Rayleigh-Debye-Gans and Mie theory for transmission simulations with spherical scatterers of different sizes and refractive indices.
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Mihaylova, Dessislava Dimitrova. « Submicron Particles and Inflammation ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18590.

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Iron nanoparticles occur naturally in the environment, but their exposure increases dramatically due to the field of nanotechnology and –medicine. It is poorly understood how the intracellular cooperative mechanisms of submicron particles and microorganisms function on mammalian immune system. In this study, superparamagnetic iron oxide (SPIO) submicron particles will be used to benefit the research within environmental diseases, addressing the biocompatibility of these particles. The size-dependent effects in the immune system of two carboxyl coated SPIO particles with stated sizes 100 nm and 1 µm will be studied in vitro. It would be interesting to determine whether these particles were able to activate the inflammasome, but still, the precise molecular mechanisms for the activation remain unknown. In order to reveal the biocompatibility of these particles, tests were performed as a function of particle concentration ranging from 0.01 to 100 µg/mL using both whole blood and peripheral blood mononuclear cells (PBMC) isolated from healthy donors. The monocytes were first primed with Lipopolysaccharide from Escherichia coli 0111:B4 strain, followed by stimulation with increasing concentrations of the submicron particles. Flow cytometry on whole blood samples identified up-regulation of CD11b monocytes and granulocytes by the particles. In addition, Terminal Complement Complex analyses proved activation of the complement system. It is possible that the particles have been coated with C3b by the complement and phagocytized by the monocytes through CD11b/CD18 receptor. Cytokine secretion from monocytes and whole blood was measured with sandwich ELISA and Bio-plex. The smaller particles seemed to induce higher inflammatory responses than the larger ones. It was, however, interesting to find that the particles themselves caused secretion of active IL-1&#946; without being primed in advance. The mechanisms of the NLRP3 inflammasome activation might be explained by ROS production due to iron imbalance in the cytoplasm. Toxicity of the particles was seen at 10 µg/mL, suggesting their potentially low biocompatibility above this concentration. However, it is suggested better biocompatibility of the silica coated 1 µm particles than the polysaccharide coated 100 nm particles.
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Mortazavi, Ramin. « Reentrainment of Submicron Solid Particles ». VCU Scholars Compass, 2005. http://scholarscompass.vcu.edu/etd/1334.

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In this work, an experimental method is developed to study the effects of particle size, flow rate, pulsation, particle/substrate material, and temperature on the short-term reentrainment of submicron particles. The particles tested are in the size range of 10-900 nm and are deposited by wetting the inside of capillary tubes with a liquid suspension. The tubes are then dried in a desiccator. The particles are reentrained under turbulent dry air flow conditions and a condensation particle counter is used to measure the number of entrained particles.There has been very limited work done with nanoscale particles in general and no previous experimental work has reported about this particular parameter set. In order to interpret the data, a bimodal lognormal probability density for the ratio of adhesion force to removal forces is suggested. The majority of particles is attached to the surface by strong forces and cannot be entrained. However, a small fraction of particles, called loose particles, is attached to the surface by much smaller forces. Based on experimental data, an analytical equation for the fraction of loose particles in terms of a dimensionless force is developed. This dimensionless force is a function of particle size and gas flow rate. The temporal variations of fraction of deposited particles are calculated by incorporating the fraction of loose particles with the model of Wen and Kasper (1989).The experimental data confirmed the theoretical expectation that entrainment strongly depends on particle size and decreases as the size of the particle decreases. Both higher flow rates and pulsation of the flow increase the entrainment. Pulsation causes the distribution of forces to broaden. It is shown that the effect of particle/substrate material on entrainment can be predicted by the compound Hamaker constant provided that the morphology and the roughness of the system remain the same. Otherwise, the effect of roughness or morphology may override the effect of Hamaker constant.
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Suwannasom, Nittiya [Verfasser]. « Biocompatibility of Biopolymer Submicron Particles / Nittiya Suwannasom ». Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2019. http://d-nb.info/1202044433/34.

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Imani, Jajarmi Ramin. « Acoustic separation of submicron particles in gaseous flows ». Licentiate thesis, KTH, Mekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-167629.

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The separation of submicron particles suspended in gaseous flows is a problem of great importance and is the subject of sustained research efforts. This is motivated by several challenges presented by modern science and technology requiring high separation efficiencies for submicron particles.Continuous acoustic particles separation is a novel technique based on the acoustophoresis phenomenon, in which a particle within an acoustic field is manipulated using acoustic forces on its surface. This technique has the potential to overcome some of the limitations of common techniques for the separation of submicron particles, as well as performing advanced tasks such as sorting particles according to their size or density.In this thesis, the separation of submicron solid particles suspended in air is investigated experimentally, with a focus on the effect of key design parameters (acoustic, flow, geometry) on the efficiency of the process. A simple method based on laser light scattering was also used to provide qualitative information on the particle number density as a function of position in the channel. This technique allowed to quickly investigate the effect of a wide range of parameters on the acoustic separation efficiency including the pressure amplitude, the frequency of the standing wave, the average flow velocity and the parallelism of the channel walls.   The results demonstrate conclusively that acoustic manipulation is possible for submicron particles and that the acoustic force scales following the trends expected from theoretical models developed in the continuum regime. From the size of the particles used it however follows that the observed separation is the result of transition regime acoustophoresis, with a Knudsen number on the order of 0.2.

QC 20150522

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Kebler, David George 1960. « Coagulation of submicron colloids by supramicron silica particles ». Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/191969.

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Values of a (coagulation efficiency) for coagulation of aluminum (hydr)oxide colloids by supramicron silica particles were generally near 0.01. Although the freshly suspended particles were oppositely charged, dissolved silica from the particulate silica adsorbs to the colloids reversing their charge. Bicarbonate also adsorbs and shifts the pHiep of the aluminum (hydr)oxide colloids. The addition of dissolved Al(III) had a similar effect on both types of particles. Dissolved silica adsorbs to the hydrous aluminum oxide surface and undergoes ligand exchange. This exchange can be simulated by a constant capacitance model for adsorption of aqueous species to the oxide surface and fits laboratory titration data.
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Gibson, Fredrick W. Jr. « Stabilization of Submicron Metal Oxide Particles in Aqueous Media ». Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30645.

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An investigation into the parameters that define a good anchor block for a copolymer steric stabilizer was performed. The study focused on the effects of different functional groups on the adsorption properties of polymers. In addition, the effect of chain architecture as well as the impact of a hydrophobic end-group on polymer adsorption properties was determined. To complement the adsorption studies, a streaming potential instrument was built for use in measuring the adsorbed layer thickness of nonionic polymers on SiO2. The research concluded with an examination of the effect of thermally induced insolubility on adsorption of a hydrogen-bonding polymer. Functional group effects were studied by measuring the adsorption isotherms of poly(2-ethyl-2-oxazoline), PEOX, poly(ethylene oxide), PEO, poly(vinyl alcohol), PVOH, and poly(ethylene imine), PEI, which was modified such that a 1,3-butanediol substituent replaced its imine hydrogens, on SiO2, TiO2, and Al2O3. PEOX and PEO, relatively basic polymers compared to PVOH were observed to adsorb only on the most acidic metal oxide, SiO2. PVOH, however, was observed to adsorb on all three metal oxides, but to a lesser degree on SiO2 as compared to the more basic PEOX and PEO. These initial results were indicative of hydrogen-bonding mechanisms, a form of acid-base interaction. The most significant observation in the adsorption studies was that the linear hydroxyl modified PEI materials and their dendritic analogs adsorb on the metal oxides both above and below the i.e.p. This indicates that both electrostatic and hydogen-bonding mechanisms are driving the adsorption. The dendritic polymers, particularly a 4th generation dendrimer based on diaminopropane with a molecular weight of 16,640 g/mol adsorbed at a higher level when compared to the 41.3K g/mol PVOH and 30K g/mol PEOX. In addition to the dual adsorption mechanism, it was determined that the dendritic architecture appears to facilitate adsorption, as does the presence of the hydrophobic endgroup. The level of adsorption for all of the hydroxyl containing linear PEI and dendritic materials on the three metal oxides was high enough for them to be considered as anchor blocks in a copolymer steric stabilizer. The streaming potential instrument used to measure the adsorbed layer thickness on SiO2. Adsorbed layer thickness of PEOX Mw = 10K and 30K g/mol were measured at approximately 1nm and 4.4 nm, respectively. In the case of the PEOX Mw = 30K g/mol homopolymer, the measured layer thickness was higher than that for a 23K g/mol PEO homopolymer. The degree of polymerization of the PEO is approximately 525, while for the PEOX it was only 300. This result was not expected. Finally, adsorption of PEOX was studied at the cloud point to determine whether insolubility could promote adsorption, while hydrogen-bonding, the room temperature driving force for adsorption, would decrease. Adsorption isotherm measurements were performed at 72 °C, and 75 °C, as the cloud point of the 30K PEOX was determined to be 73 °C. It was apparent that the adsorption decreased as temperature increased, indicating that without hydrogen bonding, thermally induced insolubility does not drive adsorption.
Ph. D.
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Livres sur le sujet "Submicronic particles"

1

Chakraborty, Jayanta. Engineering of Submicron Particles : Fundamental Concepts and Models. Wiley & Sons, Incorporated, John, 2019.

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Chakraborty, Jayanta. Engineering of Submicron Particles : Fundamental Concepts and Models. Wiley & Sons Canada, Limited, John, 2019.

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Chakraborty, Jayanta. Engineering of Submicron Particles : Fundamental Concepts and Models. Wiley & Sons, Incorporated, John, 2019.

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Chakraborty, Jayanta. Engineering of Submicron Particles : Fundamental Concepts and Models. Wiley & Sons, Limited, John, 2019.

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Zürich, Eidgenössische Technische Hochschule, dir. Emission and photoelectric precipitation of submicron particles from combustion. 1996.

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Chapitres de livres sur le sujet "Submicronic particles"

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Borghesi, A., E. Bussoletti et L. Colangeli. « Physical Properties of Submicronic Carbonaceous Particles Candidate as Cosmic Dust ». Dans Properties and Interactions of Interplanetary Dust, 159–62. Dordrecht : Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5464-9_34.

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Fontan, J., A. Lopez, E. Lamaud et A. Druilhet. « Vertical Flux Measurements of the Submicronic Aerosol Particles and Parametrisation of the Dry Deposition Velocity ». Dans Biosphere-Atmosphere Exchange of Pollutants and Trace Substances, 381–90. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-662-03394-4_30.

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Vaglieco, B. M., F. Beretta et A. D’Alessio. « Determination of the U.V.-Visible Optical Properties of Submicronic Carbonaceous Particles at High Temperature from Scattering and Extinction Measurements ». Dans Experiments on Cosmic Dust Analogues, 181–90. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3033-9_18.

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Boulaud, Denis, et Guy Madelaine. « Optical Methods in Submicronic Aerosol Measurement ». Dans Optical Particle Sizing, 573–84. Boston, MA : Springer US, 1988. http://dx.doi.org/10.1007/978-1-4757-1983-3_47.

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Brom, H. B., D. Van Der Putten et L. J. De Jongh. « NMR in Submicron Particles ». Dans Physics and Chemistry of Metal Cluster Compounds, 227–47. Dordrecht : Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-015-1294-7_8.

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Filella, Montserrat. « Colloidal Properties of Submicron Particles in Natural Waters ». Dans Environmental Colloids and Particles, 17–93. Chichester, UK : John Wiley & Sons, Ltd, 2007. http://dx.doi.org/10.1002/9780470024539.ch2.

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Bawolek, E. J., et E. D. Hirleman. « Light Scattering by Submicron Spherical Particles on Semiconductor Surfaces ». Dans Particles on Surfaces 3, 91–105. Boston, MA : Springer US, 1991. http://dx.doi.org/10.1007/978-1-4899-2367-7_8.

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Kosmulski, M. « Zeta Potential of Submicron Titania Particles in Mixed Solvents ». Dans Fine Particles Science and Technology, 185–96. Dordrecht : Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0259-6_14.

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Hayashi, C. « Ultra Fine Particles and Coatings ». Dans Frontiers in Nanoscale Science of Micron/Submicron Devices, 19–33. Dordrecht : Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1778-1_2.

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Aronov, A. G., A. D. Mirlin, P. Wölfle et E. Altshuler. « Quantum Particle in a Random Magnetic Field. » Dans Quantum Dynamics of Submicron Structures, 3–19. Dordrecht : Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0019-9_1.

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Actes de conférences sur le sujet "Submicronic particles"

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Moreau, D., L. Corté, F. Borit et V. Guipont. « Cold Spray of Agglomerated Submicronic Hydroxyapatite Powders for Biomedical Applications ». Dans ITSC 2016, sous la direction de A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen et C. A. Widener. DVS Media GmbH, 2016. http://dx.doi.org/10.31399/asm.cp.itsc2016p0006.

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Abstract In this work, two agglomerated hydroxyapatite (HA) powders, with and without heat treatment, were cold sprayed using various spraying parameters on metallic (Ti-6Al-4V) and polymeric (PVA) substrates. The structure of the agglomerated powders and corresponding features of the coatings were examined. For both types of substrates, it was shown that submicron HA powders produce homogenous layers with submicron HA grains. In the case of non-heat treated particles, thick layers could be obtained due to the binding action of residual by-products. HA layers were also found to be adherent after immersion in water, which could potentially lead to the fabrication of ceramic coated hydrogels.
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Fazilleau, J., C. Delbos, M. Violier, J.-F. Coudert, P. Fauchais, L. Bianchi et K. Wittmann-Ténèze. « Influence of Substrate Temperature on Formation of Micrometric Splats Obtained by Plasma Spraying Liquid Suspension ». Dans ITSC2003, sous la direction de Basil R. Marple et Christian Moreau. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.itsc2003p0889.

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Abstract A new thermal spray process is under development in order to produce thin coatings (thickness lower than 50 µm), with a fine microstructure (grain size smaller than 1 µm). It consists in injecting in a Direct Current (D.C.) plasma jet a suspension containing submicronic particles of the material to be deposited. To study the interaction between the plasma jet and the suspension, a system based on a pendulum allows the collection of particles at different distances from the injection point. In this paper the effect of substrate temperature upon the formation of micrometric zirconia splats was studied, glass and stainless steel were used as substrate materials.
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Delbos, C., J. Fazilleau, V. Rat, J. F. Coudert, P. Fauchais et L. Bianchi. « Finely Structured Ceramic Coatings Elaborated by Liquid Suspension Injection in a DC Plasma Jet ». Dans ITSC2004, sous la direction de Basil R. Marple et Christian Moreau. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.itsc2004p0534.

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Abstract This paper describes a study of a plasma spray process to deposit ceramic coatings with finer structures than those that can be produced by conventional DC plasma spraying. The structures are similar to those produced by plasma-enhanced chemical vapor deposition (PECVD), but with a very fast coating rate and the ability to produce a wide range of thicknesses (1 &lt; e &lt; 100 µm). The process involves injecting a ceramic suspension containing submicronic ceramic particles into a DC plasma jet. The goal is to develop the process so that it can be used for the production of such coatings as yttria stabilized zirconia (YSZ), Ni-YSZ, or perovskite (for solid oxide fuel cells) or YSZ, Al2O3-YSZ, or Pyrochlore (for thermal barrier applications). The research stage described in this paper is related to the study of the growth of YSZ coatings, to calculations of the dynamic and thermal plasma-particle transfers, linked to the effect on particle flattening of the various spray parameters (arc current intensity, particle collection distance, substrate temperature, plasma gas composition, and so on). It also describes the achievement of a multi layered coating of YSZ and alumina.
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Yakovlev, A. B. « The analysis of influence of field of co-rotation on motion of submicronic particles in the Earth’s plasmasphere ». Dans THE EIGHTH POLYAKHOV’S READING : Proceedings of the International Scientific Conference on Mechanics. Author(s), 2018. http://dx.doi.org/10.1063/1.5034628.

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Aubry, Nadine, et Pushpendra Singh. « Electrostatic Forces on Particles Floating Within the Interface Between Two Immiscible Fluids ». Dans ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-44095.

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The objective of this paper is to study the dependence of the electrostatic force that act on a particle within the interface between two immiscible fluids on the parameters such as the dielectric properties of the fluids and particles, the particle’s position within the interface, and the electric field strength. It is shown that the component of electrostatic force normal to the interface varies as a2, where a is the particle radius, and since in equilibrium it is balanced by the vertical capillary force, the interfacial deformation caused by the particle changes when an external electric field is applied. In addition, there are lateral electrostatic forces among the particles due to the dipole-dipole interactions which, when the distance between two particles is O(a), vary as a2, and remain significant for submicron sized particles.
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Abuzeid, Salem, et Ahmed A. Busnaina. « Electrostatic Effects on Submicron Particles Deposition ». Dans ASME 1991 International Computers in Engineering Conference and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/cie1991-0078.

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Abstract Laminar air flow in a two-dimensional stagnation point flow is numerically simulated. This geometry resemble the flow of air in clean room over a clean bench. The Lagrangian equation of motion of aerosol particle that includes effects of drag, gravity, lift force, Brownian motion and electrostatic force is solved numerically. The Brownian force is simulated as a Gaussian white noise random process. Trajectories of aerosol particles in the flow are evaluated and a deposition capture area which varies with particle sizes is produced. The effects of particle diameter and surface voltage on particle capture area (deposition area) are shown. Different surface voltages of 0.0, 1.0, and 4.0 kv/cm are considered. The results show that, deposition of particles increases as the surface voltage increases for all particle sizes considered. Also, the particles which have a minimum capture area are in the range of 0.50–1.0 μm. This implies that the particles which have a minimum deposition rate are in that range.
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Chen, Jim S., et Jinho Kim. « Micro Particle Transport and Deposition in Human Upper Airways ». Dans ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42928.

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The hazard caused by inhaled particles depends on the site at which they deposit within the respiratory system. Knowledge of respiratory aerosol deposition rates and locations is necessary to (1) evaluate potential health effects and establish critical exposure limits and (2) design effective inhaled medications that target specific lung regions. Particles smaller than 10 μm in diameter can be breathed into lungs and are known as inhalable particles, while most of larger particles settle in mouth and nose. Inhalable particles settle in different regions of the lungs and the settling regions depends on the particle size. The motion of a particle is mainly affected by the inertia of the particle and by the particle’s aerodynamic drag. The most important dimensionless parameters in the prediction of particle motion are the flow Reynolds number and the Stoke number, which combines the effects of particle diameter, particle density, shape factor and slip factor. The purpose of this study is to investigate the airflows in human respiratory airways. The influence of particle size on transport and deposition patterns in the 3-D lung model of the human airways is the primary concern of this research. The lung model developed for this research extends from the trachea to the segmental bronchi and it is based on Weibel’s model. The velocity field of air is studied and particle transport and deposition are compared for particles in the diameter range of 1 μm – 100 μm (G0 to G2) and 0.1 μm – 10 μm (G3 to G5) at airflow rates of 6.0, 16.7, and 30.0 L/min, which represent breathing at rest, light activity, and heavy activity, respectively. The investigation is carried out by computational fluid dynamics (CFD) using the software Fluent 6.2. Three-dimensional, steady, incompressible, laminar flow is simulated to obtain the flow field. The discrete phase model (DPM) is then employed to predict the particle trajectories and the deposition efficiency by considering drag and gravity forces. In the present study, the Reynolds number in the range of 200 – 2000 and the Stoke number in the range of 10−5 – 0.12 are investigated. For particle size over 10 μm, deposition mainly occurs by inertial impaction, where deposition generally increases with increases in particle size and flow rate. Most of the larger micron sized particles are captured at the bifurcations, while submicron sized particles flow with the fluid into the lung lower airways. The trajectories of submicron sized particles are strongly influenced by the secondary flow in daughter branches. The present results of particle deposition efficiency in the human upper airways compared well with data in the literature.
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Abuzeid, Salem, et Ahmed A. Busnaina. « Simulation of Submicron Particle Deposition in Laminar and Turbulent Stagnation Point Flows ». Dans ASME 1991 International Computers in Engineering Conference and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/cie1991-0070.

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Abstract The two dimensional laminar and turbulence stagnation-point flow over a wafer surface within a cleanroom environment are numerically simulated. This study shows the relationship between particle capture area on the wafer and the particle size and flow conditions. The mean flow field is simulated using a two equation k-ϵ turbulence model. Trajectories of aerosol particles are evaluated by solving the corresponding Lagrangian equation of motion that includes effects of drag, gravity, lift force, Brownian motion and turbulence fluctuations. The Brownian motion is modeled as a white noise process and turbulence fluctuation is assumed to behave as Gaussian random process. Simulations are carried out for aerosol particles (of various sizes) released at different locations over the surface. Depositions of particles on the wall are evaluated and a capture area which varies with particle sizes is produced. The results show that Brownian motion becomes very significant when turbulence fluctuations start to disappear near the wall for particles smaller than 1 μm in diameter. The results also show that, deposition of particles in turbulent flows are usually higher than that in laminar flows for all particle sizes considered. The effect of fluid on particle deposition rate is predicted for fluid of air and water. The results show that, particles deposition rate in air is higher than that in water.
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Ashkin, A. « Laser trapping of Rayleigh particles by a single-beam gradient force optical trap ». Dans International Laser Science Conference. Washington, D.C. : Optica Publishing Group, 1986. http://dx.doi.org/10.1364/ils.1986.thf1.

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The principles of the single-beam gradient force optical trap are considered. Laser trapping and manipulation of individual sub-micron colloids, viruses, and bacteria have been observed for the first time. Light scattering measurements were made from single particles and fixed arrays of particles. Methods of measuring particle size and orientation are discussed. Optical separation of individual particles is possible. The single-beam gradient trap operates over a range of 105 in particle size. Its use opens much of the submicron Rayleigh size range to optical trapping manipulation.
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Li, Xing, et Bofeng Bai. « Influencing Factors on Submicron Particle Movement Patterns in Supersonic Laminar Boundary Layers ». Dans ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21166.

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The process of submicron particle movement in laminar boundary layers is present in many practical applications such as the particles depositing on the turbine blade and mist droplets depositing on the surface of aircrafts. Although great progress has been made on this issue during the last decades, many underlying mechanisms still remain unclear. Here, we developed a theoretical model to understand how submicron particles will behave when they enter a supersonic laminar boundary layer above an adiabatic plate along with the main stream. In this model, we used the Lagrangian method to track the particles and calculate their trajectories, and the Eulerian method was used to calculate the flow field. Because of the large velocity and temperature gradient near the wall and the small size of the particle in this question, four forces (e.g., drag force, Saffman lift force, thermophoretic force and Brownian force) acting on the particle are considered. The effects of entering position, Mach number, the size and density of particles are investigated. We discovered that there are three particle movement patterns when they enter the supersonic boundary layer, and that the drag force and Saffman lift force play dominating roles on which pattern will happen in this process. Moreover, the results also reveal that the particle tends to move towards the wall as the diameter and the density of the particle and the Mach number of main flow increases. Finally, we suggested a dimensionless number to describe the three patterns of particle motion. This research provides a better understanding of the particle movement process in the supersonic laminar boundary layer, which can be a useful guidance for the industrial processes involving this phenomenon.
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Rapports d'organisations sur le sujet "Submicronic particles"

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Wyatt, Philip J., et Christian Jackson. Submicron Particle Analyzer. Fort Belvoir, VA : Defense Technical Information Center, avril 1990. http://dx.doi.org/10.21236/ada223558.

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McCurdy, Keith E., Alan C. Stanton et Wai K. Cheng. Study of Submicron Particle Size Distributions by Laser Doppler Measurement of Brownian Motion. Fort Belvoir, VA : Defense Technical Information Center, février 1986. http://dx.doi.org/10.21236/ada172980.

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Wicker, Louise, et Nissim Garti. Entrapment and controlled release of nutraceuticals from double emulsions stabilized by pectin-protein hybrids. United States Department of Agriculture, octobre 2004. http://dx.doi.org/10.32747/2004.7695864.bard.

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Original Objectives Specific objectives are to: (1) modify charge and hydrophobicity of pectins to improve emulsion stabilizing properties (2) develop emulsions that can be sterically stabilized using modified pectins and/or pectin/protein hybrids (3) obtain submicronal inner emulsion droplets (10-50 nanometers) with small and monodispersed double emulsion (1-2 μm) droplets with long-term stability (possibly by emulsified microemulsions) and (4) trigger and control the release at will. Background Methodology for encapsulation and controlled release of selected addenda, e.g. drugs, vitamins, phytochemicals, flavors, is of major impact in the food industries. Stable double emulsions with desired solubilization and release properties of selected addenda are formed using charge modified pectin or pectin-protein hybrids. Major conclusions, solutions, achievements * We developed methodology to isolate PME isozymes and prepared modified pectins in sufficient quantity to characterize, form single and double emulsions and test stability. *Amino acid sequence of PME isozymes was estimated and will facilitate cloning of PME for commercial application * The contribution of total charge and distribution of charge of modified pectin was determined *Soluble complexes or modified pectins and whey isolates are formed * Stable W/O/W double emulsions were formed that did not cream, had small particle size * Inner phase of double emulsions are nano-sized and stable. These new structures were termed emulsified microemulsions (EME) * Release of bioactives were controlled between a few days to months depending on layering on droplets by hybrids * Commercial testing by Israeli company of stability and release of Vitamin C showed good chemical stability Implications Resolved the major stability limitation of W/O/W emulsions. Resolved the questions regarding citrus PMEs and tailored pilot scale modification of pectins.
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Aiken, Allison C. Submicron Aerosol Chemical Composition and Optical Properties : In Situ Field Measurements and Controlled Laboratory Studies to Probe Dynamic Particle Processes for Climate. Office of Scientific and Technical Information (OSTI), juin 2019. http://dx.doi.org/10.2172/1529506.

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