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Littérature scientifique sur le sujet « Resolved particles »

Auteur : Grafiati

Publié le 1 février 2025

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Articles de revues sur le sujet "Resolved particles"

Hameete, J., M. S. Abdallah, L. C. Thijs, T. A. M. Homan, X. C. Mi, N. J. Dam et L. P. H. de Goey. « Particle-resolved hyperspectral pyrometry of metal particles ». Combustion and Flame 264 (juin 2024) : 113435. http://dx.doi.org/10.1016/j.combustflame.2024.113435.

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Kannosto, J., M. Lemmetty, A. Virtanen, J. M. Mäkelä, J. Keskinen, H. Junninen, T. Hussein, P. Aalto et M. Kulmala. « Mode resolved density of atmospheric aerosol particles ». Atmospheric Chemistry and Physics Discussions 8, n^o 2 (15 avril 2008) : 7263–88. http://dx.doi.org/10.5194/acpd-8-7263-2008.

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Abstract. In this study, we investigate the mode resolved density of ultrafine atmospheric particles measured in boreal forest environment. The method used here enables us to find the distinct density information for each mode in atmospheric fine particle population: the density values for nucleation, Aitken, and accumulation mode particles are presented. The experimental data was gained during 2 May 2005–19 May 2005 at the boreal forest measurement station "SMEAR II" in Hyytiälä, southern Finland. The density values for accumulation mode varied from 1.1 to 2 g/cm3 (average 1.5 g/cm3) and for Aitken mode from 0.4 to 2 g/cm3 (average 0.97 g/cm3. As an overall trend during the two weeks campaign, the density value of Aitken mode was seen to gradually increase. With the present method, the time dependent behaviour of the particle density can be investigated in time scale of 10 min. This allows us the follow the density evolution of the nucleation mode particles during the particle growth process following the nucleation burst. The density of nucleation mode particles decreased during the growth process. The density values for 15 nm particles were 1.2–1.5 g/cm3 and for grown 30 nm particles 0.5–1 g/cm3. These values are consistent with the present knowledge that the condensing species are semi volatile organics, emitted from the Boreal forest.

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Kannosto, J., A. Virtanen, M. Lemmetty, J. M. Mäkelä, J. Keskinen, H. Junninen, T. Hussein, P. Aalto et M. Kulmala. « Mode resolved density of atmospheric aerosol particles ». Atmospheric Chemistry and Physics 8, n^o 17 (8 septembre 2008) : 5327–37. http://dx.doi.org/10.5194/acp-8-5327-2008.

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Abstract. In this study, we investigate the mode resolved density of ultrafine atmospheric particles measured in boreal forest environment. The method used here enables us to find the distinct density information for each mode in atmospheric fine particle population: the density values for nucleation, Aitken, and accumulation mode particles are presented. The experimental data was gained during 2 May 2005–19 May 2005 at the boreal forest measurement station "SMEAR II" in Hyytiälä, Southern Finland. The density values for accumulation mode varied from 1.1 to 2 g/cm3 (average 1.5 g/cm3) and for Aitken mode from 0.4 to 2 g/cm3 (average 0.97 g/cm3). As an overall trend during the two weeks campaign, the density value of Aitken mode was seen to gradually increase. With the present method, the time dependent behaviour of the particle density can be investigated in the time scale of 10 min. This allows us to follow the density evolution of the nucleation mode particles during the particle growth process following the nucleation burst. The density of nucleation mode particles decreased during the growth process. The density values for 15 nm particles were 1.2–1.5 g/cm3 and for grown 30 nm particles 0.5–1 g/cm3. These values are consistent with the present knowledge that the condensing species are semi-volatile organics, emitted from the boreal forest.

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Kakavas, Stylianos, David Patoulias, Maria Zakoura, Athanasios Nenes et Spyros N. Pandis. « Size-resolved aerosol pH over Europe during summer ». Atmospheric Chemistry and Physics 21, n^o 2 (20 janvier 2021) : 799–811. http://dx.doi.org/10.5194/acp-21-799-2021.

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Abstract. The dependence of aerosol acidity on particle size, location, and altitude over Europe during a summertime period is investigated using the hybrid version of aerosol dynamics in the chemical transport model PMCAMx. The pH changes more with particle size in northern and southern Europe owing to the enhanced presence of non-volatile cations (Na, Ca, K, Mg) in the larger particles. Differences of up to 1–4 pH units are predicted between sub- and supermicron particles, while the average pH of PM1−2.5 can be as much as 1 unit higher than that of PM1. Most aerosol water over continental Europe is associated with PM1, while coarse particles dominate the water content in the marine and coastal areas due to the relatively higher levels of hygroscopic sea salt. Particles of all sizes become increasingly acidic with altitude (0.5–2.5 units pH decrease over 2.5 km) primarily because of the decrease in aerosol liquid water content (driven by humidity changes) with height. Inorganic nitrate is strongly affected by aerosol pH with the highest average nitrate levels predicted for the PM1−5 range and over locations where the pH exceeds 3. Dust tends to increase aerosol pH for all particle sizes and nitrate concentrations for supermicron range particles. This effect of dust is quite sensitive to its calcium content. The size-dependent pH differences carry important implications for pH-sensitive processes in the aerosol.

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Tien, Wei Hsin, et Zi-Ling Lin. « Single-Frame Lagrangian Tracking Of 3-D Acoustic Streaming Flows Using Digital Defocusing Micro Particle Streak Velocimetry ». Proceedings of the International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics 21 (8 juillet 2024) : 1–12. http://dx.doi.org/10.55037/lxlaser.21st.191.

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In this study, a single-frame particle streak velocimetry technique is applied to the classic DDPIV(Digital Defocusing Particle Image Velocimetry) concept to achieve a single-frame 3-D Lagrangian tracking of particles in microscopic flows. The shortcoming of images suffering low signal to noise ratio due to pinholes can be avoided. With the streak resolving algorithm, it allows extended exposure time when streak images are taken, and the single-frame approach also eliminates the need for high-cost and complicated synchronization hardware for double-pulse frame-straddling light sources. For each long-exposure, color-coded images received from each pinhole equipped with red, green or blue color filters, the streak-resolving algorithm is applied first to find each streak on the separate color channel, followed by an one-time triplet-matching process to group the red, green and blue streak projections. From the streak triplets, 3-D reconstruction can be done on all the resolved points on the streak, and trajectory fitting can then be applied to resolve the tracer particle trajectories in the field of view with temporal history. This procedure was applied for visualizing a microscale 3-D acoustic streaming flow pattern induced by a longitudinal spine-shaped fin oscillating at 12kHz. The height of the channel is 1mm with the spine of 0.3mm height and a 30 。 tip angle. Resolved flow fields show that the particle streak images can be resolved with the same level of accuracy to the particle tracking method, while the throughput of velocity vectors can be significantly higher due to multiple velocity vectors can be resolved from each streak triplet. The methodology has the potential to be applied to various applications that can capture long-exposure images and possible to resolve higher-order information such as acceleration and forces applied on the particles or the flow.

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Kontkanen, Jenni, Chenjuan Deng, Yueyun Fu, Lubna Dada, Ying Zhou, Jing Cai, Kaspar R. Daellenbach et al. « Size-resolved particle number emissions in Beijing determined from measured particle size distributions ». Atmospheric Chemistry and Physics 20, n^o 19 (5 octobre 2020) : 11329–48. http://dx.doi.org/10.5194/acp-20-11329-2020.

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Abstract. The climate and air quality effects of aerosol particles depend on the number and size of the particles. In urban environments, a large fraction of aerosol particles originates from anthropogenic emissions. To evaluate the effects of different pollution sources on air quality, knowledge of size distributions of particle number emissions is needed. Here we introduce a novel method for determining size-resolved particle number emissions, based on measured particle size distributions. We apply our method to data measured in Beijing, China, to determine the number size distribution of emitted particles in a diameter range from 2 to 1000 nm. The observed particle number emissions are dominated by emissions of particles smaller than 30 nm. Our results suggest that traffic is the major source of particle number emissions with the highest emissions observed for particles around 10 nm during rush hours. At sizes below 6 nm, clustering of atmospheric vapors contributes to calculated emissions. The comparison between our calculated emissions and those estimated with an integrated assessment model GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) shows that our method yields clearly higher particle emissions at sizes below 60 nm, but at sizes above that the two methods agree well. Overall, our method is proven to be a useful tool for gaining new knowledge of the size distributions of particle number emissions in urban environments and for validating emission inventories and models. In the future, the method will be developed by modeling the transport of particles from different sources to obtain more accurate estimates of particle number emissions.

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Yu, X. Y., J. P. Cowin, M. J. Iedema et H. Ali. « Fast time-resolved aerosol collector : proof of concept ». Atmospheric Measurement Techniques Discussions 3, n^o 3 (1 juin 2010) : 2515–34. http://dx.doi.org/10.5194/amtd-3-2515-2010.

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Abstract. Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC") microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4–17 ms in this setup), and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

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Yu, X. Y., J. P. Cowin, M. J. Iedema et H. Ali. « Fast time-resolved aerosol collector : proof of concept ». Atmospheric Measurement Techniques 3, n^o 5 (12 octobre 2010) : 1377–84. http://dx.doi.org/10.5194/amt-3-1377-2010.

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Guo, S., M. Hu, Z. B. Wang, J. Slanina et Y. L. Zhao. « Size-resolved aerosol water-soluble ionic compositions in the summer of Beijing : implication of regional secondary formation ». Atmospheric Chemistry and Physics 10, n^o 3 (1 février 2010) : 947–59. http://dx.doi.org/10.5194/acp-10-947-2010.

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Abstract. To characterize aerosol pollution in Beijing, size-resolved aerosols were collected by MOUDIs during CAREBEIJING-2006 field campaign at Peking University (urban site) and Yufa (upwind rural site). Fine particle concentrations (PM1.8 by MOUDI) were 99.8±77.4 μg/m3 and 78.2±58.4 μg/m3, with PM1.8/PM10 ratios of 0.64±0.08 and 0.76±0.08 at PKU and Yufa, respectively, and secondary compounds accounted for more than 50% in fine particles. PMF model analysis was used to resolve the particle modes. Three modes were resolved at Yufa, representing condensation, droplet and coarse mode. However, one more droplet mode with bigger size was resolved, which was considered probably from regional transport. Condensation mode accounted for 10%–60% of the total mass at both sites, indicating that the gas-to-particle condensation process was important in summer. The formation of sulfate was mainly attributed to in-cloud or aerosol droplet process (PKU 80%, Yufa 70%) and gas condensation process (PKU 14%, Yufa 22%). According to the thermodynamic instability of NH4NO3, size distributions of nitrate were classified as three categories by RH. The existence of Ca(NO3)2 in droplet mode indicated the reaction of HNO3 with crustal particles was also important in fine particles. A rough estimation was given that 69% of the PM10 and 87% of the PM1.8 in Beijing urban were regional contributions. Sulfate, ammonium and oxalate were formed regionally, with the regional contributions of 90%, 87% and 95% to PM1.8. Nitrate formation was local dominant. In summary regional secondary formation led to aerosol pollution in the summer of Beijing.

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Lu, Senlin, Teng Ma, Lu Zhang, Yule Feng, Shumin Zhou, Wei Zhang, Shinichi Yonemochi et al. « Relationships between Mass Level of Allergenic Platanus acerifolia Protein 3 (Pla a3) and Redox Trace Elements in the Size-Resolved Particles in Shanghai Atmosphere ». Atmosphere 13, n^o 10 (21 septembre 2022) : 1541. http://dx.doi.org/10.3390/atmos13101541.

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Allergenic pollen protein can be released from pollen grains and suspended in the air to cause allergenic reactions. However, the allergenic protein and its relationship with redox trace elements in ambient size-resolved particles has not been reported. Ambient size-resolved particles in Shanghai’s atmosphere were sampled during the Platanus pollen season in the spring season of 2017. Planatus pollen protein 3 (Pla a3) and redox trace elements in the ambient particles were investigated and their relationship was analyzed. Our data demonstrated that the mass level of the Pla a3 in the size-resolved particles ranged from 0.41 ± 0.28 to 7.46 ± 2.23 pg/m3, and decreased with the size range. Mass concentrations (ppb) of crustal elements (Fe, Al, Ca, Mg, Na) in the size-resolved particles ranged from 20.11 ± 9.87 to 1126.22 ± 659.51, while trace elements (V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Pb) varied from 0.05 ± 0.03 to 57.53 ± 19.7. Mass levels of these trace elements decreased according to particle size. The Abundance of redox trace elements, including Fe (R2 = 0.82), Mn (R2 = 0.54), Cu (R2 = 0.61), Ba (R2 = 0.82), and Pb (R2 = 0.82) in the size-resolved particles was significantly related to that of Pla a3, and our data implied redox trace elements might take syngenetic effects on the allergenicity induced by Pla a3 protein.

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Thèses sur le sujet "Resolved particles"

Chadil, Mohamed-Amine. « Penalty methods for the simulation of fluid-solid interactions with various assemblies of resolved scale particles ». Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0205/document.

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Les simulations des écoulements diphasiques à l’échelle réelle de l’application nécessitent des modèles pour les termes non fermés des équations macroscopiques. Des simulations numériques directes à particule résolue utilisant la méthode de pénalisation visqueuse ont été réalisées afin de mesurer les interactions entre des particules de différentes formes (sphérique et ellipsoïdale) et le fluide porteur à différents régimes d'écoulement (de stokes à l'inertiel). Deux méthodes ont été développées durant cette thèse afin d'extraire les forces hydrodynamiques ainsi que le transfert de chaleur sur les frontières immergées représentant les particules. Plusieurs validations ont été conduites pour différentes configurations de particules : de la simulation d’une particule isolée à un réseau aléatoire de sphères en passant par réseau cubique face centrée de sphères. Une corrélation du nombre de Nusselt est proposée pour un sphéroïde allongé plongé dans un écoulement uniforme
The simulations of multiphase flows at real application scale need models for unclosed terms in macroscopic equations. Particle-Resolved Direct Numerical Simulations using Viscous Penalty Method have been carried out to quantify the interactions between particles of different shapes (spheres, ellipsoids) and the carrier fluid at different regimes (from Stokes to inertial). Two methods have been developed to extract hydrodynamic forcesand heat transfers on immersed boundaries representing the particles. Validations have been conducted for various configuration of particles: from an isolated sphere and spheroid to Face-Centered Cubic to a random arrangement of spheres. A correlation of the Nusselt number for an isolated prolate spheroid past by a uniform flow is proposed

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He, Long. « Study of Fluid Forces and Heat Transfer on Non-spherical Particles in Assembly Using Particle Resolved Simulation ». Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/91400.

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Gas-solid flow is fundamental to many industrial processes. Extensive experimental and numerical studies have been devoted to understand the interphase momentum and heat transfer in these systems. Most of the studies have focused on spherical particle shapes, however, in most natural and industrial processes, the particle shape is seldom spherical. In fact, particle shape is one of the important parameters that can have a significant impact on momentum, heat and mass transfer, which are fundamental to all processes. In this study particle-resolved simulations are performed to study momentum and heat transfer in flow through a fixed random assembly of ellipsoidal particles with sphericity of 0.887. The incompressible Navier-Stokes equations are solved using the Immersed Boundary Method (IBM). A Framework for generating particle assembly is developed using physics engine PhysX. High-order boundary conditions are developed for immersed boundary method to resolve the heat transfer in the vicinity of fluid/particle boundary with better accuracy. A complete framework using particle-resolved simulation study assembly of particles with any shape is developed. The drag force of spherical particles and ellipsoid particles are investigated. Available correlations are evaluated based on simulation results and recommendations are made regarding the best combinations. The heat transfer in assembly of ellipsoidal particle is investigated, and a correlation is proposed for the particle shape studied. The lift force, lateral force and torque of ellipsoid particles in assembly and their variations are quantitatively presented and it is shown that under certain conditions these forces and torques cannot be neglected as is done in the larger literature.
Ph. D.

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Lui, Kwok-on, et 呂國安. « Single particle analysis by time-resolved ICP-MS measurement ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46582630.

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Payne, Stephen John. « Critical scattering and time resolved neutron diffraction studies of phase transitions ». Thesis, Keele University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245355.

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Zhang, Hua, et 张华. « Characterization of signal-production processes of single particles inICP by time-resolved ICP-AES ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47150567.

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The research in this thesis aims to characterize the signal-production processes of single particles in the ICP using time-resolved ICP-AES. Signal-production processes, including desolvation, vaporization, atomization, ionization, and diffusion, determine the temporal emission intensity of a single particle. Bimetallic nanoparticles of BaTiO3 (average diameter = 115 nm) were used as test particles. The particles were introduced into the ICP by nebulization of the suspension of the particles in water. As the ion plume of a particle moves up in central channel of the ICP, a temporal emission peak of the analyte atoms in the plume is produced. The emission intensity at any point of time in the temporal profile is related to the degree of vaporization and excitation of the particle at the corresponding vertical position of the ICP. The signal-production processes can, in principle, be studied by measuring the temporal emission profiles. However, the emission intensity of single particles is typically low. Continuous integration of the entire ICP central channel further reduces the signal-to-background ratio (SBR). A novel double-slit method has been developed to measure the temporal emission intensity of a single particle at two pre-defined ICP vertical positions. Two horizontal slits of slit height of 1 mm were placed in front of the monochromator. As the ion plume passes through the double-slit, two peaks in the temporal emission profile are produced. The configuration of the double-slit (slit height and distance between the two slits) was optimized for maximum signal-to-noise ratio (SNR) and temporal resolution of the double-peaks. Fast data sampling rate (50,000 Hz) was used in proper sampling of the temporal emission peaks. Large data sets were obtained. Custom programs were developed to extract the relatively weak double-peaks from the temporal emission profiles. The data treatment strategy includes smoothing of the temporal profile to increase SNR and automated peak extraction based on the characteristics of the double-peaks (peak height, peak width, time-difference of the peak pair, and SNR). Four smoothing methods, including Moving Average Filtering, Savitzky-Golay Filtering, Fast Fourier Transform (FFT) and Wavelet Transform, were tested. FFT was adopted because the method requires only one parameter (the cutoff frequency) and is relatively easy to optimize. Hundreds of double-peaks were obtained in a typical temporal profile of time duration of approximately 120 s. The emission intensity and peak width of the peak pair are correlated to determine the degree of vaporization of the analyte atoms, the extent of diffusion of the analyte atoms and the plume size, and the velocity of the plume in the ICP. Two types of double-peaks are identified. The relative peak height and peak width of the double-peaks in each type are related to the degree of vaporization of the single particles. Simulation of the evaporation rate of water droplets that enclose the single BaTiO3 particles shows that the time required for complete evaporation of water is a major factor that determines the degree of vaporization of BaTiO3 particles at the double-slit. Aggregation of BaTiO3 particles in the suspension was also investigated.
published_or_final_version
Chemistry
Master
Master of Philosophy

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Benia, Hadj Mohamed. « Spatially resolved optical measurements on supported metal particles and oxide surfaces with the STM ». Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15862.

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In der vorliegenden Arbeit wurde mit Hilfe eines Photon-STM die Korrelation zwischen optischen Eigenschaften und der lokalen Morphologie an zwei unterschiedlichen Systemen untersucht. Hierfür wurden zum einem oxidgetragene Ensemble von Silber-Partikeln präpariert, wobei sowohl die Partikelform (Kuppel- und Scheibenform) als auch die deponierte Partikeldichte variiert werden konnte. Neben der Präparation solcher Partikel auf Al10O13/NiAl, konnten sphärische Silber-Kolloide geordnet, als auch ungeordnet auf HOPG aufgebracht und untersucht werden. Dabei zeigte sich, dass das Verhältnis von Höhen zu Breiten nicht nur einen signifikanten Einfluss auf die Mie-Resonanz des einzelnen Partikels hat, sondern auch die elektromagnetische Kopplung der Partikel in einem Ensemble stark kontrolliert. Die energetische Lage der Mie-Resonanz zeigt im Fall der kuppelförmigen Ag-Partikel eine starke Abhängigkeit vom Intepartikel-Abstand, was sich in einer Verschiebung zu höheren Energien für eine steigende Partikeldichte äußert. Eine solche Abhängigkeit konnte bei den Ensembles der scheibenförmigen Partikel nicht beobachtet werden. Des weiteren zeigte sich, dass, verglichen mit den ungeordneten Ensembles, die selbstorganisierte langreichweitige Ordnung der Silber-Kolloide auf HOPG nur einen schwachen Einfluss auf die energetische Position der Mie Resonanz hat.Das zweite hier untersuchte System sind dünne MgO Filme unterschiedlicher Dicken auf einem Mo(001) Substrat. Diese zeigen ein reichhaltiges Wachstumsverhalten, welches durch eine Differenz in den Gitterkonstanten von 5.3% begründet ist und erst ab etwa 25 ML zu einem flachen und defektarmen Film führt. Die so induzierte Spannung relaxiert bis zu einer Dicke von etwa 7 ML in einer periodischen Überstruktur die aus abwechselnd flachen und verkippten Ebenen an der MgO-Mo Grenzschicht hervorgeht. Für MgO Filme mit einer Dicke von etwa 12 ML werden dann Schraubenversetzungen, ausgedehnte verkippte Ebenen und Stufenkanten mit einer Orientierung entlang der Richtung beobachtet. Die optische Charakterisierung durch Feldemission von Elektronen aus der STM-Spitze in den MgO-Film wird dominiert von zwei Emissionsmaxima bei Energien von 3.1 eV und 4.4 eV. Die kontrollierte Nukleation von Gold Partikeln und die Erzeugung von Farbzentren im MgO Film erlaubten eine Zuordnung dieser Emissionen zu strahlenden Zerfällen von Exitonen an Ecken, Kinken bzw. Stufen des Magnesiumoxids. Solche Emissionsprozesse konnten allerdings nur unter Einstellungen beobachtet werden, bei denen ein gleichzeitiges Rastern der Oberfläche unmöglich ist. Bei moderaten Einstellungen war auch eine ortsaufgelösten Spektroskopie möglich, wobei dann neue Emissionsmechanismen beobachtet wurden. Dabei sind zwei Prozesse wesentlich; zum einen die Ausbildung von sog. Spitzen-induzierten Plasmonen im Bereich zwischen Spitze und dem Mo-Substrat, zum anderen strahlende Elektronenübergänge zwischen sog. Feldemissionsresonanzen, die sich im Spitze/MgO-Film System ausbilden.
In this thesis, the correlation between the optical properties and the local morphology of supported silver nanoparticle ensembles and MgO thin films deposited on Mo(001) systems is explored by means of Photon-STM. In the first section, dome and disk shaped Ag nanoparticle ensembles with increasing density on an alumina film on NiAl(110) were analyzed as well as ordered and disordered ensembles of Ag nanocolloids on HOPG. The aspect ratio of the Ag nanoparticles was found to have a significant influence not only on the Mie plasmon resonance of a single particle, but also on the electromagnetic coupling within the nanoparticle ensembles. The Mie resonance in the ensemble of dome shaped Ag nanoparticles shows a strong dependence on the interparticle distance, where it shifts to higher energies with increasing particle density, due to destructive interference effects. In the disk-like Ag ensembles, however, the plasmon energy is independent of particle-particle separation. The long-range lateral ordering of size-selected Ag nanocolloids is found to induce a high dipole-dipole coupling within the ensemble. This is mainly reflected by the enhancement of the spectral intensity of the in-plane Mie mode, due to constructive coupling. However, ensembles with either well-ordered or disordered arrangements reveal no important difference in their optical properties, reflecting the weak influence of the long-range order in the particle ensemble. Thin MgO films with different thicknesses were grown on a Mo(001) surface. The stress resulting from the 5.3% lattice mismatch between the MgO(001) and the Mo(001) lattice parameters is found to control the surface morphology of the MgO film until thicknesses of around 25ML at which flat and defect-poor films are obtained. The relaxation of the stress induces a periodic network in the first 7ML of the MgO film, consisting of alternated flat and tilted mosaics. The presence of screw dislocations, steps oriented along the MgO directions, and tilted planes is observed when the MgO films are approximately 12ML thick. In addition, an increase of the MgO work function around these new surface features is revealed from STM spectroscopy. The photon emission induced by field-emitted electron injection from the STM tip into the MgO films is dominated by two emission bands located at 3.1eV and 4.4eV. To check the origin of these bands, further experiments, namely, nucleation of Au particles and creation of F-centers on the MgO surface, have been performed. The nucleation of Au particles at the low coordinated sites is found to quench the MgO optical signal, while the creation or annihilation of F-centers does not alter the MgO emission bands. The 3.1eV and the 4.4eV bands are therefore assigned to the radiative decay of MgO excitons at corner and kink sites, and step sites, respectively. Besides, spatially resolved optical measurements in the tunneling mode of the STM revealed different light emission mechanisms. These radiative processes are mainly related to tip-induced plasmons that form between the tip and the Mo support and to electron transitions between field-emission-resonance states in the STM tip-MgO film junction. The signal from exciton decays at corners and kinks of the MgO surface is however only observed at excitation conditions where the spatial resolution is already strongly reduced.

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Tufano, Giovanni Luigi [Verfasser], et Andreas [Akademischer Betreuer] Kronenburg. « Fully-resolved simulations of ignition and combustion of single coal particles and coal particle clouds / Giovanni Luigi Tufano ; Betreuer : Andreas Kronenburg ». Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2021. http://d-nb.info/123911608X/34.

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Shingler, Taylor, et Taylor Shingler. « Investigations of Physicochemical Properties of Size-Resolved, Subsaturated, Atmospheric Aerosol Particles : Instrument Development, Field Measurements, and Data Analysis ». Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/620958.

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Aerosol particle properties and their impact on air quality, clouds, and the hydrologic cycle remain a critically important factor for the understanding of our atmosphere. Particle hygroscopic growth leads to impacts on direct and indirect radiative forcing properties, the likelihood for particles to act as cloud condensation nuclei, and aerosol-cloud interactions. Current instruments measuring hygroscopic growth have a number of limitations, lacking either the ability to measure size-resolved particles or process samples at a fast enough resolution to be suitable for airborne deployment. Advanced in-situ airborne particle retrieval and measurements of aerosol hygroscopic growth and scattering properties are analyzed and discussed.To improve the analysis of cloud nuclei particles, an updated counterflow virtual impact inlet was characterized and deployed during the 2011 E-PEACE field campaign. Theoretical and laboratory based cut size diameters were determined and validated against data collected from an airborne platform. In pursuit of higher quality aerosol particle hygroscopicity measurements, a newer instrument, the differential aerosol sizing and hygroscopicity probe (DASH-SP) has been developed in the recent past and only flown on a handful of campaigns. It has been proven to provide quality, rapid, size-resolved hygroscopic growth factor data, but was further improved into a smaller form factor making it easier for deployment on airborne platforms. It was flown during the 2013 SEAC4RS field campaign and the data was analyzed to composite air mass based hygroscopicity and refractive index (real portion only) statistics. Additionally, a comparison of bulk and size-resolved hygroscopic growth measurements was conducted. Significant findings include a potential particle size bias on bulk scattering measurements as well as a narrow range of ambient real portion of refractive index values. An investigation into the first reported ambient hygroscopicity measurements of particle shrinkage, or "sub-1" growth is conducted. Possible explanations, including particle restructuring, measurement sensitivity to refractive index, evaporative loss, and influence of ambient external mixtures on data processing are examined.

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Shrestha, Kristina. « Time-Resolved Temperature Measurements and Thermal Imaging using Nano-Thermometers in Different Environments ». Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1593706274306985.

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Chan, Alan Jenkin. « 3D Time-Resolved Hetero-Coagulation of Soft Latex and Hard Colloidal Particles and the Structuration of the Resulting Gel Network ». Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS026.

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Le caoutchouc naturel (NR pour Natural Rubber) est une matière première indispensable à la fabrication de milliers de produits !Le choix du latex naturel tient principalement à ses propriétés physico-chimiques intrinsèques bien supérieures à celles des latex synthétiques. Industriellement, le NR est cependant rarement utilisé seul mais associé à des particules de renfort, appelées charges, pour former un matériau composite aux propriétés mécaniques grandement améliorées en particulier la résistance à l’usure.Des études récentes ont mis en évidence que la méthode conventionnelle consistant à introduire les charges sous forme de poudres fines au sein d’un bloc de NR solide ou fondu n’est pas la plus efficace. Une nouvelle approche consistant à mélanger les deux entités, NR et charges, en phase liquide avant séchage s’annonce prometteuse industriellement, mais la littérature à ce sujet est encore très limitée. Ce travail de thèse a visé à parfaire la compréhension des processus gouvernant les interactions NR-charges renforçantes en phase liquide. Pour ce faire nous avons (i) décrit les propriétés physico-chimiques de surface des particules NR en phase liquide, (ii) étudier les effets de la charge renforçante (en termes de taille, composition, fonctionnalisation de surface, concentration) et de la solution (ions valence) sur l'interaction NR-charge et (iii) quantifier les propriétés mécaniques des particules NR.Nous avons été en mesure d’identifier les paramètres clés qui permettent en phase aqueuse diluée, non seulement d’influencer l’interaction particule de NR-charge mais aussi de réguler la dynamique d'interaction et de contrôler la structure des hétéro-agrégats formés.Cette approche originale de l’hétérocoagulation NR-charge en phase liquide ouvre de nombreuses perspectives en vue d’améliorer les propriétés des matériaux composites NR-particules de renfort
Natural rubber (NR) is an indispensable raw material used in the manufacturing of more than 40,000 products primarily due to its excellent intrinsic physical properties. However, NR is seldom used in its raw state. Often, it needs to be reinforced with particulate fillers (nanoparticles) to further improve its physical strength required for most applications. The precise origin of this mechanical reinforcement effect remains unclear, however, optimal reinforcements appears to depend on the dispersion of filler in the NR matrix and the interaction of NR and filler.It was found that the conventional method of pouring fine powders in a solid block of rubber/melt is not the most efficient way to disperse the fillers. The new alternative approach in which the two components are first dispersed in liquid has shown promising results but available literature is still very limited. Furthermore, the microscopic mechanism involved in the interaction of NR and filler in liquid is still unknown. In this context, we (i) described the physico-chemical surface properties of NR particles in liquid, (ii) identified key filler (size, composition, surface activity, concentration) and solution (ion valence) related parameters to comprehend the structural, morphological, and dynamical evolution of the NR-filler interaction, and (iii) quantified the mechanical properties of the NR particles. With this approach we were able to provide the first reports on the physical processes involved in the interaction of NR and filler. More importantly, a recipe for the basic yet crucial parameters that controls and modulates NR-filler heteroaggregation was established. This could open the way to further understand the reinforcement effect

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Livres sur le sujet "Resolved particles"

Rohrlich, F. Relativistic particle electrodynamics : How its problems got resolved. [Ahmedabad : Physical Research Laboratory], 1992.

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Helmut, Schober, Nagler Stephen E et SpringerLink (Online service), dir. Studying Kinetics with Neutrons : Prospects for Time-Resolved Neutron Scattering. Berlin, Heidelberg : Springer-Verlag Berlin Heidelberg, 2010.

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1934-, Cardona Manuel, et Merlin R. 1950-, dir. Light scattering in solids. Berlin : Springer, 2007.

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Office, General Accounting. Air pollution : EPA's actions to resolve concerns with the fine particulate monitoring program : report to the Chairman, Subcommittee on VA, HUD, and Independent Agencies, Committee on Appropriations, House of Representatives. [Washington, D.C.] : The Office, 1999.

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Office, General Accounting. Air pollution : New approach needed to resolve safety issue for vapor recovery systems : report to the chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House of Representatives. Washington, D.C : GAO, 1991.

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Brown, D. W. Conformational transitions of nucleosome core particles monitored with time-resolved fluorescence spectroscopy. 1992.

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Hüglin, Christoph. New applications of aerosol photoemission : Characterization of wood combustion particles and time resolved thermal desorption studies. 1996.

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Stuewer, Roger H. The Cambridge–Vienna Controversy. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198827870.003.0004.

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The intense Cambridge–Vienna controversy, which was carried out in the literature and in private correspondence, lasted six years. It was resolved in December 1928, when Chadwick visited Meyer’s institute in Vienna and found that under Pettersson and Kirsch’s influence their women scintillation counters had fallen prey to a misleading psychological effect. That was never published in the literature, however, so outsiders could only sense that something had gone seriously wrong in Meyer’s institute, which greatly affected its scientific reputation. The major positive consequence of the controversy was that it encouraged the further development of electrical techniques for counting charged particles to replace human scintillation counters.

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Eckold, Götz, Helmut Schober et Stephen E. Nagler. Studying Kinetics with Neutrons : Prospects for Time-Resolved Neutron Scattering. Springer, 2012.

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Lattman, Eaton E., Thomas D. Grant et Edward H. Snell. Biological Small Angle Scattering. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199670871.001.0001.

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The technique of small angle solution scattering has been revolutionized in the last two decades. Exponential increases in computing power, parallel algorithm development, and the development of synchrotron, free-electron X-ray sources, and neutron sources, have combined to allow new classes of studies for biological specimens. These include time-resolved experiments in which functional motions of proteins are monitored on a picosecond timescale, and the first steps towards determining actual electron density fluctuations within particles. In addition, more traditional experiments involving the determination of size and shape, and contrast matching that isolate substructures such as nucleic acid, have become much more straightforward to carry out, and simultaneously require much less material. These new capabilities have sparked an upsurge of interest in solution scattering on the part of investigators in related disciplines. Thus, this book seeks to guide structural biologists to understand the basics of small angle solution scattering in both the X-ray and neutron case, to appreciate its strengths, and to be cognizant of its limitations. It is also directed at those who have a general interest in its potential. The book focuses on three areas: theory, practical aspects and applications, and the potential of developing areas. It is an introduction and guide to the field but not a comprehensive treatment of all the potential applications.

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Chapitres de livres sur le sujet "Resolved particles"

Abdelsamie, A. H., et D. Thévenin. « Modulation of Isotropic Turbulence by Resolved and Non-resolved Spherical Particles ». Dans Direct and Large-Eddy Simulation IX, 621–29. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14448-1_78.

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Weber, Th, E. Riedle et H. J. Neusser. « Rotationally resolved ultraviolet spectra of benzene-noble gas van der Waals clusters ». Dans Small Particles and Inorganic Clusters, 493–96. Berlin, Heidelberg : Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76178-2_117.

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Lindinger, M., K. Dasgupta, G. Dietrich, S. Krückeberg, S. Kuznetsov, K. Lützenkirchen, L. Schweikhard, C. Walther et J. Ziegler. « Time resolved photofragmentation of Au n + and Ag n + clusters (n = 9, 21) ». Dans Small Particles and Inorganic Clusters, 347–50. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60854-4_82.

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Wallimann, Franz, Hans-Martin Frey, Samuel Leutwyler et Mark Riley. « Isotopically resolved $$ \widetilde{B} \leftarrow \widetilde{X} $$ electronic spectrum of Ag3 and calculation of its Jahn-Teller effects ». Dans Small Particles and Inorganic Clusters, 30–35. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60854-4_8.

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Fischer, D., B. Feuerstein, R. Moshammer, J. R. Crespo López-Urrutia, I. Draganic, H. Lörch, A. N. Perumal, J. Ullrich et R. D. Dubois. « Subshell Resolved Measurements of Single Electron Capture in Slow Ne7+-Helium Collisions ». Dans Atomic Physics at Accelerators : Stored Particles and Fundamental Physics, 177–81. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-007-0946-1_28.

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Hérissan, Alexandre, Mohamed Nawfal Ghazzal, Marinus Kunst et Christophe Colbeau-Justin. « Time Resolved Microwave Conductivity : Studying Mobile Charge-Carriers in TiO2 Photoactive Particles ». Dans Springer Handbook of Inorganic Photochemistry, 315–38. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-63713-2_13.

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Poggi, G., M. Bini, A. Olmi, P. R. Maurenzig, G. Pasquali, N. Taccetti et P. Danielewicz. « Study of the Dynamics of the Au+Au Collisions by Means of Isotope-Resolved Emitted Light Particles ». Dans NATO ASI Series, 493–504. Boston, MA : Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-2516-5_43.

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Searle, Geoff, Frans van Mieghem et Tjeerd Schaafsma. « Some Zero- and High-Field Electron Spin Resonance and Time-Resolved Fluorescence Studies on Isolated Photosystem II Particles ». Dans Techniques and New Developments in Photosynthesis Research, 229–32. Boston, MA : Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-8571-4_25.

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Ondov, J. M., F. Divita, T. L. Quinn et M. Han. « Applications of Highly-Resolved Size-Spectra for Source Attribution, Growth, and Deposition of Urban Aerosol Particles Bearing Various Elements ». Dans Urban Air Pollution, 187–97. Berlin, Heidelberg : Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-61120-9_15.

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Ernst, M., et M. Sommerfeld. « Resolved Numerical Simulation of Particle Agglomeration ». Dans Colloid Process Engineering, 45–71. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-15129-8_3.

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Actes de conférences sur le sujet "Resolved particles"

Sydney, Anish, et J. Leishman. « Measurements of the Plume-like Three-Dimensionality of Rotor-Induced Dust Fields ». Dans Vertical Flight Society 70th Annual Forum & Technology Display, 1–20. The Vertical Flight Society, 2014. http://dx.doi.org/10.4050/f-0070-2014-9436.

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To better understand the problem of rotor-induced particle motion and rotorcraft brownout, time-resolved, dual-phase particle image velocimetry and particle tracking velocimetry measurements were made in the flow produced by a small laboratory rotor that was hovering over a mobile sediment bed. The main goal was to further investigate the three-dimensionality of the rotor wake and how its interaction with the sediment bed led to the formation of distinct columnar plumes of uplifted sediment particles. Dual-phase flow measurements were made in both vertical and horizontal planes around the rotor and near the ground. The results showed that the rotor wake was extremely three-dimensional, with non-uniform velocities near the ground that resulted in the radially asymmetric uplift of particles throughout the flow field. The helicoidal vortex filament developed wave-like displacements along their lengths, which caused some parts of the filaments to convect closer to the ground. The parts of the filaments that were closer to the ground were observed to interact with the near-wall flow there, sometimes causing the boundary layer to briefly detach and introduce secondary vorticity into the flow. Adjacent turns of the interdigitated helicoidal vortex filaments often merged together, creating significantly larger upwash/downwash regions near the ground, which produced discrete bursts of sediment mobilization and uplift.

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Cuautle, E., I. A. Maldonado-Cervantes, Heriberto Castilla-Valdez, Omar Miranda et Eli Santos. « Resolved Component in Heavy Quark Photoproduction ». Dans PARTICLES AND FIELDS : XI Mexican Workshop on Particles and Fields. AIP, 2008. http://dx.doi.org/10.1063/1.2965062.

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Burton, Tristan M., et John K. Eaton. « Fully Resolved Simulations of Stationary Particles in Turbulent Flow ». Dans ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45721.

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Gas flows containing a dilute loading of solid particle constitute an important class of multiphase flows. In most cases the gas flow is turbulent, and the interactions between the particles and the turbulence offer major modeling challenges. Many numerical models implicitly assume that the particles are significantly smaller than all turbulence length scales. Simple particle drag laws derived for uniform steady flow around a sphere are used to compute the motion of point-particles, and to determine the magnitude of the point-forces that are applied to the gas phase in order to produce turbulence modification. This technique may be appropriate if the particle is small relative to any turbulent eddies, but in many practical problems the particle diameter, d, is of the same order as the flow Kolmogorov scale, η. Here we perform fully-resolved simulations of a fixed particle in decaying homogeneous isotropic turbulence using an overset grid method. All flow scales are accurately resolved with this technique including the effect of the no-slip boundary condition at the particle surface. A set of 29 simulations with an initial Taylor microscale Reynolds number, Reλ = 32.2, and Kolmogorov length scale, η = 0.45d are computed to obtain a useful statistical sample. The turbulent kinetic energy and viscous dissipation near the particle surface in laden and unladen simulations are compared to provide understanding of the turbulence modification process. We anticipate that these results will provide direction for the development of turbulence modification models suitable for larger scale simulations where the flow cannot be resolved to the particle surface.

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Nakamura, Arao, et Takashi Tokizaki. « Femtosecond Time–Resolved Thermomodulation of Small Copper Particles in Glass ». Dans International Conference on Ultrafast Phenomena. Washington, D.C. : Optica Publishing Group, 1994. http://dx.doi.org/10.1364/up.1994.md.2.

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In recent years, optical nonlinearity of small metal particles in dielectric has attracted much attention, because of the possibility of the high polarizability and the fast response [1,2]. Enhancement of the local field inside the particle at the surface plasmon resonance causes enhancement of a third–order nonlinear susceptibility χ (3).

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Daun, K. J., B. J. Stagg, F. Liu, G. J. Smallwood et D. R. Snelling. « Determining Aerosol Particle Size Distribution Using Time-Resolved Laser-Induced Incandescence ». Dans ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13595.

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Time-resolved laser-induced incandescence is a powerful tool for determining the physical characteristics of aerosol dispersions of refractory nano-particles. In this procedure, particles within a small aerosol volume are heated with a nano-second laser pulse, and the temporal incandescence of the particles is then measured as they return to the ambient gas temperature. It is possible to infer particle size distribution from the temporal decay of the LII signal since the cooling rate of an individual particle depends on its area-to-volume ratio. This requires solving a mathematically ill-posed inverse problem, however, since the measured LII signal is due to the incandescence contributed by all particle sizes within the aerosol volume. This paper reviews techniques proposed in the literature for recovering particle size distributions from time-resolved LII data. The characteristics of this ill-posed problem are then discussed in detail, particularly the issues of solution stability and uniqueness. Finally, the accuracy and stability of each method is evaluated by performing a perturbation analysis, and the overall performance of the techniques is compared.

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Portela, Lui´s M., et Rene´ V. A. Oliemans. « Subgrid Particle-Fluid Coupling Evaluation in Large-Eddy Simulations of Particle-Laden Flows ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33113.

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Point-particle Eulerian-Lagrangian DNS/LES simulations allow us to deal with a large number of small particles, using relatively modest computer resources. When doing LES, one can consider the subgrid particle-fluid coupling, using a subgrid model, or simply ignore it. We present a criterion to evaluate the importance of the subgrid particle-fluid coupling on: (i) the particle motion, and (ii) the resolved fluid-motion. The criterion assumes that the particles can be treated as point-particles, from the perspective of both the resolved and subgrid motions, and it is based on simple “local equilibrium” models for the interaction between the particles and the subgrid fluid-motion. The criterion was applied to a high-resolution channel flow LES, with a moderate particle-loading. The results indicate that: (i) for heavy particles, the common practice of ignoring the subgrid particle-fluid coupling is adequate, (ii) for very-light particles a model for the subgrid-driven particle-velocity fluctuations might be important.

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Redding, B., Y. Pan, C. Wang, G. Videen et Hui Cao. « Polarization resolved angular optical scattering of aerosol particles ». Dans SPIE Sensing Technology + Applications, sous la direction de Tuan Vo-Dinh, Robert A. Lieberman et Günter G. Gauglitz. SPIE, 2014. http://dx.doi.org/10.1117/12.2050022.

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Breugem, Wim-Paul. « A Combined Soft-Sphere Collision/Immersed Boundary Method for Resolved Simulations of Particulate Flows ». Dans ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30634.

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A second-order accurate and efficient Immersed Boundary Method (IBM) has been developed for simulating particle-laden flows. Recently, this method has been combined with a soft-sphere collision model to accommodate inter-particle and particle-wall collisions. Details of the collision model are given. Results are shown from a lubrication study of non-touching particles at close distance from each other. The numerical results for the drag force acting on the particles agree well with exact solutions, except when the gap width between the particles becomes significantly smaller than the numerical grid spacing. For very small gap width, lubrication force corrections are proposed for the normal approach between particles based on asymptotic analytical solutions. Results are presented from a numerical study of sphere-wall collisions in a viscous fluid. The simulated behavior of the coefficient of restitution as function of the Stokes number based on the particle impact velocity, is in good agreement with experimental data.

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Cheng, Y., M. M. Torregrosa et F. J. Diez. « Novel Particle Shift Filtering Method for Simultaneous Two Phase Separation in Time Resolved Stereo PIV Measurements ». Dans ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-43784.

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This paper describes a novel particle shift filtering method to study jets laden with particles by separating the 3D velocity field of the two phases. Multiphase jets laden with particles appear in many engineering and environmental processes. Typical examples are sprays containing liquid fuel drops in combustion processes, air jets laden with coal particles in a power plant, and the dispersion of harmful substances like soot and pollutants from steady exhaust flows or waste waters, among others. Distribution and mixing of particles/drops in these processes determine the efficiency of the engineering systems concerned but studies of particle-laden turbulent flows suggest that particle distribution is not uniform but preferential. In order to understand the mechanism of particle dispersion, the dispersed phase (particles/drops) needs to be separated from the ambient flow (tracer particles). A new technique is proposed that builds on previous work done by Kiger & Pan (2000) and Khalitov & Longmire (2002). The later work used a discrimination algorithm for two-phase 2D PIV where the tracer particles are differentiated from the dispersed phase based on size and brightness intensity. The present work expands on that technique and introduces a 3D velocity discrimination algorithm of two-phase flows for time resolved stereo PIV.

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Abdelsamie, Abouelmagd, Amir Eshghinejad Fard, Timo Oster et Dominique Thévenin. « Impact of the Collision Model for Fully Resolved Particles Interacting in a Fluid ». 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/fedsm2014-21447.

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The impact of the collision model employed when simulating fully resolved particles interacting in a fluid is investigated in the present study. We are using for this purpose a p seudo-spectral in compressib le Direct Numerical Simulation (DNS) code based on the Navier-Stokes equation as well as a Lattice-Boltzmann Method (LBM), developed in our group and coupled with the direct-forcing Immersed Boundary Method (IBM) to describe the particles. Most of the corresponding literature assumes that the collision model does not have a significant impact on the flow field. Additionally, the impact of the collision model on the particle trajectories has not been analyzed in a systematic manner. Thus, by using the DNS solver, four different collision models (velocity barrier, repulsive potential force, lubrication barrier and hard-sphere model) have been employed in order to examine consequences for particle behavior and turbulence structure. It was found that the particle motion and turbulence statistics are qualitatively similar for all models. However, noticeable quantitative differences appear concerning the turbulent dissipation rate. In the LBM section two different types of repulsive-force collision model are selected and their effect on a 2D fluid-particle interaction is investigated. Furthermore, other factors affecting performance of the LB-IBM solver, like the forcing scheme will be discussed.

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Rapports d'organisations sur le sujet "Resolved particles"

Robins, Lawrence H., Edward N. Farabaugh et Albert Feldman. Spatially and Spectrally Resolved Cathodoluminescence of Hot-Filament Chemical-Vapor-Deposited Diamond Particles. Fort Belvoir, VA : Defense Technical Information Center, avril 1991. http://dx.doi.org/10.21236/ada236485.

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Robins, Lawrence H. Spatially and Spectrally Resolved Cathodoluminescence of Hot-Filament Chemical-Vapor-Deposited Diamond Particles. Fort Belvoir, VA : Defense Technical Information Center, avril 1991. http://dx.doi.org/10.21236/ada237128.

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Leeb, Helmut, Paraskevi Dimitriou et Ian J. Thompson. R-Matrix Codes for Charged-particle Induced Reactionsin the Resolved Resonance Region. Office of Scientific and Technical Information (OSTI), janvier 2017. http://dx.doi.org/10.2172/1343028.

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Leeb, Helmut, Paraskevi Dimitriou et Ian Thompson. R-Matrix Codes for Charged-particle Reactionsin the Resolved Resonance Region (4). IAEA Nuclear Data Section, novembre 2018. http://dx.doi.org/10.61092/iaea.59jc-2d3b.

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A Consultants’ Meeting was held at the IAEA Headquarters from 27 to 29 August 2018, to discuss the results of a coordinated effort to verify R-matrix codes through a well-defined exercise. Six R-matrix codes were included in this verification exercise: AMUR, AZURE2, EDA, RAC, SFRESCOX, and SAMMY. Furthermore, the contents of the final publication of this exercise were considered in this meeting. This report summarizes the presentations and technical discussions of the meeting, as well as any additional actions that were proposed.

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Farmer, Delphine. Final Report : Size-resolved particle and black carbon deposition over the cryosphere. Office of Scientific and Technical Information (OSTI), janvier 2024. http://dx.doi.org/10.2172/2282780.

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Leeb, Helmut, Paraskevi Dimitriou et Ian Thompson. R-Matrix Codes for Charged-particle Reactions in the Resolved Resonance Region (5). IAEA Nuclear Data Section, septembre 2019. http://dx.doi.org/10.61092/iaea.4jec-5ph0.

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Consultants’ Meeting was held at the IAEA Headquarters from 13 to 14 May 2019, to discuss the results of a coordinated effort to verify the minimization techniques implemented in the R-matrix codes through a well-defined exercise. Five R-matrix codes were included in this second exercise: AZURE2, CONRAD, EDA, SFRESCOX, and SAMMY. Furthermore, the final exercise which is the evaluation of the 7Be system was agreed upon at this meeting. This report summarizes the presentations and technical discussions of the meeting, as well as any additional actions that were proposed.

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Dimitriou, Paraskevi, Richard J. deBoer, Satoshi Kunieda, Mark Paris, Ian Thompson et Andrej Trkov. R-Matrix Codes for Charged-particle Induced Reactionsin the Resolved Resonance Region (1). IAEA Nuclear Data Section, mars 2016. http://dx.doi.org/10.61092/iaea.wxc8-dp6j.

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Leeb, Helmut, Paraskevi Dimitriou et Ian Thompson. R-Matrix Codes for Charged-Particle Induced Reactions in the Resolved Resonance Region (3). IAEA Nuclear Data Section, septembre 2017. http://dx.doi.org/10.61092/iaea.easz-q1z1.

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Leeb, Helmut, Richard J. deBoer, Ian Thompson et Paraskevi Dimitriou. Summary Report of the IAEA Consultants’ Meetings of the International Nuclear Data Evaluation Network (INDEN) on the Evaluation of Light Elements (3). IAEA Nuclear Data Section, juillet 2021. http://dx.doi.org/10.61092/iaea.x6kd-w5qa.

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The INDEN for Light Elements network (INDEN-LE) held two virtual Consultants’ Meetings, one on R-matrix calculations for charged-particle reactions in the resolved resonance region, from 15 to 16 March 2201, and one on the evaluation of light systems produced by neutrons, from 17 to 19 March 2021. The purpose of the meetings was to review the status of the inter-comparisons of covariances and the full evaluation of the 7Be* system on the one hand, and the evaluation of n+9Be, n+14,15N, and n+23Na systems, on the other. A session dedicated to the emerging data needs for (α,n) reaction data was held on 18th March 2021. Summaries of the presentations and discussions can be found in this report.

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Chen, Zhenpeng, et Yeying Sun. A Global Fitting Method with hte R-Matrix Code RAC. IAEA Nuclear Data Section, décembre 2019. http://dx.doi.org/10.61092/iaea.zr3b-121v.

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This report introduces the evaluation method RAC-CERNGEPLIS and the results obtained for the project “R-matrix Codes for Charged-particle Induced Reactions in the Resolved Resonance Region” that is coordinated by the Nuclear Data Section. In fact, this method has been used before in the evaluation of the compound systems n+6Li and n+10B, for the IAEA Neutron Standards (2006 and 2017 release). The main characteristics of the RAC code are that i) the eliminated channel width is included in the R-matrix algorithm and ii) the Generalized-Least Square method is used in the fitting procedure. In this report we discuss different approaches to R-Matrix fitting that are used in nuclear data evaluation. Practice shows that the RAC-CERNGEPLIS method is a reasonable, useful and powerful tool for evaluation of nuclear data.

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