Academic literature on the topic 'Aerosol density'
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Journal articles on the topic "Aerosol density"
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Mane, Dr Pratibha Bhagavanrao. "To Reveal the Aerosol Vertical Profiles in Terms of Aerosol Number Density." Indian Journal of Applied Research 3, no. 12 (2011): 521–23. http://dx.doi.org/10.15373/2249555x/dec2013/158.
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Seifert, M., J. Ström, R. Krejci, et al. "Aerosol-cirrus interactions: A number based phenomenon at all?" Atmospheric Chemistry and Physics Discussions 3, no. 4 (2003): 3625–57. http://dx.doi.org/10.5194/acpd-3-3625-2003.
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Abstract. In situ measurements of the partitioning of aerosol particles within cirrus clouds were used to investigate aerosol-cloud interactions in ice clouds. The number density of interstitial aerosol particles (non-activated particles in between the cirrus crystals) was compared to the number density of cirrus crystal residuals. The data was obtained during the two INCA (Interhemispheric Differences in Cirrus Properties form Anthropogenic Emissions) campaigns, performed in the Southern Hemisphere (SH) and Northern Hemisphere (NH) midlatitudes. Different aerosol-cirrus interactions can be linked to the different stages of the cirrus lifecycle. Cloud formation is linked to positive correlations between the number density of interstitial aerosol (Nint) and crystal residuals (Ncvi), whereas the correlations are smaller or even negative in a dissolving cloud. Unlike warm clouds, where the number density of cloud droplets is positively related to the aerosol number density, we observed a rather complex relationship when expressing Ncvi as a function of Nint for forming clouds. The data sets are similar in that they both show local maxima in the Nint range 100 to 200 cm−3, where the SH-maximum is shifted towards the higher value. For lower number densities Nint and Ncvi are positively related. The slopes emerging from the data suggest that a tenfold increase in the aerosol number density corresponds to a 3 to 4 times increase in the crystal number density. As Nint increases beyond the ca. 100 to 200 cm−3, the mean crystal number density decreases at about the same rate for both data sets. For much higher aerosol number densities, only present in the NH data set, the mean Ncvi remains low. The situation for dissolving clouds presents two alternative interactions between aerosols and cirrus. Either evaporating clouds are associated with a source of aerosol particles, or air pollution (high aerosol number density) retards evaporation rates.
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Chen, Qi-Xiang, Chun-Lin Huang, Yuan Yuan, Qian-Jun Mao, and He-Ping Tan. "Spatiotemporal Distribution of Major Aerosol Types over China Based on MODIS Products between 2008 and 2017." Atmosphere 11, no. 7 (2020): 703. http://dx.doi.org/10.3390/atmos11070703.
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Knowledge of aerosol-type distribution is critical to the evaluation of aerosol–climate effects. However, research on aerosol-type distribution covering all is limited. This study characterized the spatiotemporal distribution of major aerosol types over China by using MODerate resolution Imaging Spectroradiometer (MODIS) products from 2008 to 2017. Two aerosol-type classification methods were combined to achieve this goal. One was for relatively high aerosol load (AOD ≥ 0.2) using aerosol optical depth (AOD) and aerosol relative optical depth (AROD) and the other was for low aerosol load (AOD < 0.2) using land use and population density information, which assumed that aerosols are closely related to local emissions. Results showed that the dominant aerosol-type distribution has a distinct spatial and temporal pattern. In western China, background aerosols (mainly dust/desert dust and continent aerosol) dominate with a combined occurrence ratio over 70% and they have slight variations on seasonal scale. While in eastern China, the dominant aerosols show strong seasonal variations. Spatially, mixed aerosols dominate most parts of eastern China in spring due to the influence of long-range transported dust from Taklamakan and Gobi desert and urban/industry aerosols take place in summer due to strong photochemical reactions. Temporally, mixed and urban/industry aerosols co-dominate eastern China.
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Seifert, M., J. Ström, R. Krejci, et al. "Aerosol-cirrus interactions: a number based phenomenon at all?" Atmospheric Chemistry and Physics 4, no. 2 (2004): 293–305. http://dx.doi.org/10.5194/acp-4-293-2004.
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Abstract. In situ measurements of the partitioning of aerosol particles within cirrus clouds were used to investigate aerosol-cloud interactions in ice clouds. The number density of interstitial aerosol particles (non-activated particles in between the cirrus crystals) was compared to the number density of cirrus crystal residuals. The data was obtained during the two INCA (Interhemispheric Differences in Cirrus Properties from Anthropogenic Emissions) campaigns, performed in the Southern Hemisphere (SH) and Northern Hemisphere (NH) midlatitudes. Different aerosol-cirrus interactions can be linked to the different stages of the cirrus lifecycle. Cloud formation is linked to positive correlations between the number density of interstitial aerosol (Nint) and crystal residuals (Ncvi), whereas the correlations are smaller or even negative in a dissolving cloud. Unlike warm clouds, where the number density of cloud droplets is positively related to the aerosol number density, we observed a rather complex relationship when expressing Ncvi as a function of Nint for forming clouds. The data sets are similar in that they both show local maxima in the Nint range 100 to 200cm, where the SH- maximum is shifted towards the higher value. For lower number densities Nint and Ncvi are positively related. The slopes emerging from the data suggest that a tenfold increase in the aerosol number density corresponds to a 3 to 4 times increase in the crystal number density. As Nint increases beyond the ca. 100 to 200cm, the mean crystal number density decreases at about the same rate for both data sets. For much higher aerosol number densities, only present in the NH data set, the mean Ncvi remains low. The situation for dissolving clouds allows us to offer two possible, but at this point only speculative, alternative interactions between aerosols and cirrus: evaporating clouds might be associated with a source of aerosol particles, or air pollution (high aerosol number density) might retard ice particle evaporation rates.
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Tsigaridis, K., Y. Balkanski, M. Schulz, and A. Benedetti. "Global error maps of aerosol optical properties: an error propagation analysis." Atmospheric Chemistry and Physics Discussions 8, no. 4 (2008): 16027–59. http://dx.doi.org/10.5194/acpd-8-16027-2008.
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Abstract. Among the numerous atmospheric constituents, aerosols play a unique role on climate, due to their scattering and absorbing capabilities, visibility degradation and their effect on incoming and outgoing radiation. The most important optical properties are the aerosol optical depth (AOD), the asymmetry parameter (g) and the single scattering albedo (SSA). Uncertainties in aerosol microphysics in global models, which in turn affect their optical properties, propagate to uncertainties on the effect of aerosols on climate. This study aims to estimate the uncertainty of AOD, g and SSA attributable to the aerosol representation in models, namely mixing state, aerosol size and aerosol associated water. As a reference, the monthly mean output of the general circulation model LMDz-INCA from the international comparison exercise AEROCOM B was used. For the optical properties calculations, aerosols were considered either externally mixed, homogeneously internally mixed or coated spheres. The radius was allowed to vary by ±20% (with 2% intervals) and the aerosol water content by ±50% (with 5% intervals) with respect to the reference model output. All of these possible combinations were assumed to be equally likely and the optical properties were calculated for each one of them. A probability density function (PDF) was constructed at each model grid point for AOD, g and SSA. From this PDF, the 1σ and 2σ uncertainties of the AOD, g and SSA were calculated and are available as global maps for each month. For the range of the cases studied, we derive a maximum 2σ uncertainty range in AOD of 70%, while for g and SSA the maxima reach 18% and 28% respectively. The mixing state was calculated to be important, with the aerosol absorption and SSA being the most affected properties when absorbing aerosols are present.
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Nagaraja, Kamsali, S. D. Pawar, P. Murugavel, and V. Gopalakrishnan. "Electrical Conductivity of the Stratosphere." Mapana - Journal of Sciences 12, no. 1 (2013): 39–47. http://dx.doi.org/10.12723/mjs.24.5.
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Ionic conductivity of the stratosphere is one of the important parameters for understanding the electrical state of the region. This parameter is sensitive to the presence of aerosols and thus, aerosol loading on the stratosphere has a bearing on the conductivity. Preliminary efforts were made to study the behaviour of stratospheric ion conductivity and its variation under enhanced aerosol conditions by making use of an Ion-aerosol model. The aerosol ion-small ion recombination coefficient obtained from the model determines the extent to which aerosols can alter the conductivity of the stratosphere. This necessitates the requirement of experimental measurements of attachment and recombination coefficient along with simultaneously measured aerosol density to have the proper information on electrical conductivity of the region.
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Zhao, Pengguo, Zhanqing Li, Hui Xiao, et al. "Distinct aerosol effects on cloud-to-ground lightning in the plateau and basin regions of Sichuan, Southwest China." Atmospheric Chemistry and Physics 20, no. 21 (2020): 13379–97. http://dx.doi.org/10.5194/acp-20-13379-2020.
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Abstract. The joint effects of aerosol, thermodynamic, and cloud-related factors on cloud-to-ground lightning in Sichuan were investigated by a comprehensive analysis of ground-based measurements made from 2005 to 2017 in combination with reanalysis data. Data include aerosol optical depth, cloud-to-ground (CG) lightning density, convective available potential energy (CAPE), mid-level relative humidity, lower- to mid-tropospheric vertical wind shear, cloud-base height, total column liquid water (TCLW), and total column ice water (TCIW). Results show that CG lightning density and aerosols are positively correlated in the plateau region and negatively correlated in the basin region. Sulfate aerosols are found to be more strongly associated with lightning than total aerosols, so this study focuses on the role of sulfate aerosols in lightning activity. In the plateau region, the lower aerosol concentration stimulates lightning activity through microphysical effects. Increasing the aerosol loading decreases the cloud droplet size, reducing the cloud droplet collision–coalescence efficiency and inhibiting the warm-rain process. More small cloud droplets are transported above the freezing level to participate in the freezing process, forming more ice particles and releasing more latent heat during the freezing process. Thus, an increase in the aerosol loading increases CAPE, TCLW, and TCIW, stimulating CG lightning in the plateau region. In the basin region, by contrast, the higher concentration of aerosols inhibits lightning activity through the radiative effect. An increase in the aerosol loading reduces the amount of solar radiation reaching the ground, thereby lowering the CAPE. The intensity of convection decreases, resulting in less supercooled water being transported to the freezing level and fewer ice particles forming, thereby increasing the total liquid water content. Thus, an increase in the aerosol loading suppresses the intensity of convective activity and CG lightning in the basin region.
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Furtado, Kalli, and Paul Field. "A strong statistical link between aerosol indirect effects and the self-similarity of rainfall distributions." Atmospheric Chemistry and Physics 22, no. 5 (2022): 3391–407. http://dx.doi.org/10.5194/acp-22-3391-2022.
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Abstract. We use convective-scale simulations of monsoonal clouds to reveal a self-similar probability density function that underpins surface rainfall statistics. This density is independent of cloud-droplet number concentration and is unchanged by aerosol perturbations. It therefore represents an invariant property of our model with respect to cloud–aerosol interactions. For a given aerosol concentration, if the dependence of at least one moment of the rainfall distribution on cloud-droplet number is a known input parameter, then the self-similar density can be used to reconstruct the entire rainfall distribution to a useful degree of accuracy. In particular, we present both single-moment and double-moment reconstructions that are able to predict the responses of the rainfall distributions to changes in aerosol concentration. In doing so, we show that the seemingly high-dimensional space of possible aerosol-induced rainfall-distribution transformations can be parameterised by surprisingly few (at most 3) independent “degrees of freedom”: the self-similar density and auxiliary information about two moments of the rainfall distribution. Comparisons to convection-permitting forecasts of mid-latitude weather and atmosphere-only global simulations show that the self-similar density is also independent of model physics and background meteorology. A theoretical explanation for this invariance is given, based on numerical results from a stochastic rainfall simulator. This suggests that, although aerosol indirect effects on any specific hydro-meteorological system may be multifarious in terms of rainfall changes and physical mechanisms, there may, nevertheless, be a universal constraint on the number of independent degrees of freedom needed to represent the dependencies of rainfall on aerosols.
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Kukfisz, Bozena. "Flammability parameters of sprayed and foam aerosols selected for studies." MATEC Web of Conferences 247 (2018): 00029. http://dx.doi.org/10.1051/matecconf/201824700029.
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The paper presents classification criteria for flammability parameters of sprayed and foamed aerosols [1-3]. Tests were carried out to determine such flammability criteria, as combustion heat of a substance, distance of sprayed aerosol from the ignition source at which ignition takes place, time equivalent necessary for ignition to take place and the density of deflagration for sprayed aerosols. For foamed aerosols the determined parameters comprised combustion heat parameters for a substance, the maximum flame height and the flame retention time. Based on the obtained flammability it may be unequivocally stated that aerosol products pose a serious fire hazard. Aerosols selected for testing pose a serious explosion hazard within a confined space. It seems that from among all the tested aerosols the most hazardous products in this respect comprise solvent and stain remover and DW 40. Within a space of 200 dm3 those products required 3 and 4 seconds of aerosol spraying respectively until the moment of initiating an explosion. Aerosol products in which use was made of propane-butane a carrier gas characterise by very similar flammability and explosivitiy parameters within a closed or confined space.
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Dinar, E., T. F. Mentel, and Y. Rudich. "The density of humic acids and humic like substances (HULIS) from fresh and aged wood burning and pollution aerosol particles." Atmospheric Chemistry and Physics Discussions 6, no. 4 (2006): 7835–67. http://dx.doi.org/10.5194/acpd-6-7835-2006.
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Abstract. Atmospheric aerosols play significant roles in climatic related phenomena. The density and shape of particles dominates their fluid-dynamic parameters which in turn dictate their transport and lifecycle. Moreover, density and shape are also related to the particles optical properties, influencing their regional and global radiative effects. In the present study we have measured and compared the densities of humic like substances (HULIS) extracted from smoke and pollution aerosol particles to those of molecular weight-fractionated aquatic and terrestrial Humic Substances (HS). The density was measured by comparing the mobility and aerodynamic diameter of aerosol particles composed of these compounds. Characterization of chemical parameters such as molecular weight, aromaticity and elemental composition allow us to test how they affect the density of these important environmental macromolecules. It is found that atmospheric aging processes increase the density of HULIS due to the oxidation, while packing due to the aromatic moieties plays important role in determining the density of the aquatic HS substances.
Dissertations / Theses on the topic "Aerosol density"
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Wang, Shuo. "Retrieval of Aerosol Chemical Composition based on aerosol optical properties." Thesis, Littoral, 2020. https://tel.archives-ouvertes.fr/tel-03178823.
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La composition chimique des aérosols permet de mieux comprendre leurs interactions avec le changement climatique et la santé humaine. La composition chimique des aérosols est étroitement liée aux propriétés optiques. Actuellement, les propriétés optiques des aérosols sont mesurées, intégrées ou non sur la colonne atmosphérique, à une échelle globale. Le développement d'algorithmes permettant de déterminer, à une résolution spatiale et temporelle élevée, la composition chimique des aérosols à partir de leurs propriétés optiques est essentiel. Ce travail de thèse vise à tester et à améliorer les méthodes actuelles de classification et d'estimation de la composition chimique des aérosols. (1) Méthodes basées sur le coefficient d'Ǻngström (AE) : ces méthodes s'appuient sur la dépendance spectrale du coefficient de diffusion (SAE) et d'absorption (AAE). En effet, de nombreuses recherches distinguent les différents types d'aérosols en fonction de leur SAE et AAE. Afin de déterminer des valeurs seuils des SAE et AAE pour différents aérosols absorbants, la dépendance spectrale du SAE et AAR en fonction de la taille des particules, l'épaisseur relative d'une éventuelle couche surfacique et les longueurs d'ondes choisies pour le calcul. Les résultats montrent que SAE et AAE dépendent fortement des longueurs d'onde utilisées et sont également fortement affectés par la taille de l'aérosol. Les différents types de particules peuvent exister dans l'atmosphère dans les mêmes classes de taille et dans ce cas, SAE et AAE ne peuvent pas être utilisés pour distinguer efficacement ces différents composants.(2) Méthodes basées sur k : le but de ces méthodes est d'estimer la concentration massique des différents composants de l'aérosol à partir de la paie imaginaire de l'indice de réfraction (CRI, m=n + k i). A partir des indices de réfraction et de la variation spectrale de l'albédo à diffusion unique (dSSA), reportés par le réseau AERONET, la variation de la composition chimique des aérosols intégrée sur la colonne a été estimée puis comparée à la distribution saisonnière des émissions d'aérosols couplée au transport régional pendant différentes saisons. Cette comparaison montre des résultats très encourageants même si les compositions chimiques sont sensiblement différentes (intégrées sur la colonne et estimée en surface). La validation de cette méthode nécessite donc de disposer de jeux de mesures de la composition chimique plus comparables.(3) Méthode de k-p : afin de faciliter la distinction entre les poussières minérales (MD) et le carbone organique (OC), une nouvelle méthode basée sur la partie imaginaire du CRI (k) et de la densité des aérosols (p) a été développée. L'application de cet algorithme sur des données (propriétés optiques et physiques) recueillies lors d'une campagne d'observation à Shouxian permet d'obtenir la variation de la composition chimique des aérosols en temps réel. La composition chimique de l'aérosol estimé par cette méthode est cohérente avec les résultats des mesures in-situ. La concentration massique des MD est la moins bien estimée par cet algorithme (R²=0.43) probablement dur à une plus grande incertitude dans la mesure<br>Aerosol chemical composition is an essential factor to better understand aerosol interactions with climate change, atmospheric environment and human health. Aerosol optical property is closely associated to chemical composition. Nowadays, vertical and global aerosol optical properties are measured. Development of aerosol chemical composition retrieval algorithm based on optical properties is essential to derive aerosol chemical composition with high spatial and temporal resolution. This thesis aims to test and improve the present methods for aerosol chemical composition classification and retrieval. (1) Ǻngström Exponent (AE) methods : these methods are based on Scattering (SAE) ans Absorption (AAE) AE to derive absorption coefficients by different aerosols or distinguish aerosol types, but many studies used different SAE and AAE values or thresholds. To understand these discrepancies, SAE and AAE dependencies to particle size, relative coating thickness and wavelength pairs were studied for different absorbing aerosols. The results reveal that SAE and AAE depend on wavelength pairs used for calculations and are also greatly influenced by aerosol size, thus knowledge of aerosol size information could reduce the uncertainty of calculating absorption coefficients by different aerosols using AAE. As aerosol particles could exist within the same size bin, SAE and AAE cannot be used to distinguish different compositions effectively by setting thresholds.(2)k-based methods : these methods aim to retrieve the mass concentrations of different aerosol compounds based on the imaginary part of Complex Refractive Index (CRI, m=n + k i). For the application and examination of the k-based methods, columnar aerosol chemical compositions were retrieved based on CRI and spectral variation of Single Scattering Albedo (dSSA) using long-term AERONET measurements. Dependence of retrieved columnar aerosol chemical compositions on regional transported was investigated in different seasons. This result is comparable to seasonal aerosol emission distribution and transport process. But the reliable aerosol chemical composition at the same level is still needed to verify algorithm. (3) k-p method : to tackle the difficulty to distinguish Organic Carbon (OC), from Mineral Dust (MD), a new method based on CRI imaginary part (k) and aerosol density (p) was developed. This algorithm was used to obtain the real-time aerosol chemical composition varation during an observation campaign in Shouxian. The retrieved aerosol chemical compositions were consistent with in-situ measurements.The weaker agreement (R²=0.43) of MD compared to the other species is due to the larger uncertainties from retrievals and measurements
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Gilbertson, Sarah Elizabeth. "Aerosol Gel production via controlled detonation of liquid precursors." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/1101.
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Cross, Eben Spencer. "Sources and transformations of atmospheric aerosol particles." Thesis, Boston College, 2008. http://hdl.handle.net/2345/971.
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Thesis advisor: Paul Davidovits<br>Aerosol particles are an important component of the Earth-Atmosphere system because of their influence on the radiation budget both directly (through absorption and scattering) and indirectly (through cloud condensation nuclei (CCN) activity). The magnitude of the raditaive forcing attributed to the direct and indirect aerosol effects is highly uncertain, leading to large uncertainties in projections of global climate change. Real-time measurements of aerosol properties are a critical step toward constraining the uncertainties in current global climate modeling and understanding the influence that anthropogenic activities have on the climate. The objective of the work presented in this thesis is to gain a more complete understanding of the atmospheric transformations of aerosol particles and how such transformations influence the direct and indirect radiative effects of the particles. The work focuses on real-time measurements of aerosol particles made with the Aerodyne Aerosol Mass Spectrometer (AMS) developed in collaboration with the Boston College research group. A key feature of the work described is the development of a lightscattering module for the AMS. Here we present the first results obtained with the integrated light scattering – AMS system. The unique and powerful capabilities of this new instrument combination are demonstrated through laboratory experiments and field deployments. Results from two field studies are presented: (1) The Northeast Air Quality Study (NEAQS), in the summer of 2004, conducted at Chebogue Point, Nova Scotia and (2) The Megacity Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in and around Mexico City, Mexico in March of 2006. Both field studies were designed to study the transformations that occur within pollution plumes as they are transported throughout the atmosphere. During the NEAQS campaign, the pollution plume from the Northeastern United States was intercepted as it was transported towards Europe. In this study, particles were highly processed prior to sampling, with residence times of a few days in the atmosphere. The MILAGRO campaign focused on the evolution of the Mexico City plume as it was transported north. During this study, regional and locally emitted particles were measured with residence times varying from minutes to days in the atmosphere. In both studies, the light scattering – AMS system provided detailed information about the density and composition of single particles, leading to important insights into how atmospheric processing transforms the particle properties. In Mexico City, the light scattering-AMS system was used for the first time as a true single particle mass spectrometer and revealed specific details about the atmospheric processing of primary particles from combustion sources.To quantify the radiative effects of the particles on climate, the processing and ultimate fate of primary emissions (often containing black carbon or soot) must be understood. To provide a solid basis for the interpretation of the data obtained during the field studies, experiments were conducted with a well characterized soot generation-sampling system developed by the Boston College research group. The laboratory soot source was combined with the light scattering – AMS system and a Cloud Condensation Nuclei Counter (CCNC) to measure the change in cloud-forming activity of soot particles as they are processed in the atmosphere. Because of the importance of black carbon in the atmosphere, several instruments have been developed to measure black carbon. In July of 2008, an intercomparison study of 18 instruments was conducted in the Boston College laboratory, with soot particles produced and processed to mimic a wide range of atmospherically-relevant conditions. Transformations in the physical, chemical, and optical properties of soot particles were monitored with the combined suite of aerosol instrumentation. Results from the intercomparison study not only calibrated the different instruments used in the study, but also provided critical details about how atmospheric processing influences the radiative effects of primary combustion particles<br>Thesis (PhD) — Boston College, 2008<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Lim, Tongli. "Fabrication of high energy density tin/carbon anode using reduction expansion synthesis and aerosol through plasma techniques." Thesis, Monterey, California: Naval Postgraduate School, 2017. http://hdl.handle.net/10945/53011.
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Approved for public release; distribution is unlimited<br>The aim of this study was to fabricate tin/carbon (Sn/C) battery anodes using a novel approach, reduction expansion synthesis (RES), and test their performance as electrodes in lithium or sodium batteries. A second preparation route, the Aerosol-Through-Plasma (ATP) method, was also employed for comparison. The specimens generated were characterized, before and after cycling, using techniques such as X-ray diffraction, scanning, and transmission electron microscopy. The RES technique was successful in creating remarkably small (ca. <5 nm) nano-scale particles of tin dispersed on the carbon support. The use of the electrodes as part of coin cell batteries resulted in capacitance values of 320 mAh/g and 110 mAh/g for lithium-ion and sodium-ion batteries, respectively. Nano-sized Sn particles were found before and after cycling. It is believed that bonds between metal atoms and dangling carbon produced via the reduction of the carbon surface during RES were responsible for the materials' ability to withstand stresses during lithiation, avoid volumetric expansion, and prevent disintegration after hundreds of cycles. When tin loading in Sn/C was increased from 10% to 20%, an increase of capacitance from 280 mAh/g to 320mAh/g was observed; thus, increased tin loading is recommended for future studies. Tin/carbon produced using ATP presented morphology consistent with stable electrodes, although battery testing was not completed because of the difficulty of producing the material in sufficient quantity.<br>Military Expert 5, Republic of Singapore Navy
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Johnson, Graham Richard. "The Formation and Growth of Marine Aerosols and the Development of New Techniques for their In-situ Analysis." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16117/1/Graham_Johnson_Thesis.pdf.
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Marine aerosols have attracted increasing attention over the past 15 years because of
their potential significance for global climate modelling. The size distribution of these
aerosols extends from super-micrometer sea salt mode particles down through 150 nm
accumulation mode particles, 40 nm Aitken mode particles and nucleation mode
particles which extend from 25 nm right down to clusters of a few molecules. The
process by which the submicrometer modes form and grow and their composition
have remained topics of debate throughout this time in large part because of the
difficulties associated with determining their composition and relating it to proposed
models of the formation process.
The work compared the modality of marine aerosol influencing the South-east-Queensland region with that of other environmental aerosols in the region. The aerosol was found to be consistent with marine aerosols observed elsewhere with
concentrations below 1000 cm-3 and frequently exhibiting the distinct bimodal structure associated with cloud processing, consisting of an Aitken mode at approximately 40 nm, an accumulation mode in the range 100-200 nm and a coarse mode attributed to sea salt between 600 and 1200 nm.
This work included the development of two new techniques for aerosol research. The first technique measures aerosol density using a combination of aerosol size distribution and gravimetric mass concentration measurements. This technique was used to measure the density of a number of submicrometer aerosols including
laboratory generated NaCl aerosol and ambient aerosol. The densities for the laboratory generated aerosols were found to be similar to those for the bulk materials used to produce them. The technique, extended to super-micrometer particle size range may find application in ambient aerosol research where it could be used to discriminate between periods when the aerosol is dominated by NaCl and periods
when the density is more representative of crustal material or sulfates. The technique
may also prove useful in laboratory or industrial settings for investigating particle
density or in case where the composition is known, morphology and porosity.
The second technique developed, integrates the existing physicochemical techniques
of volatilisation and hygroscopic growth analysis to investigate particle composition
in terms of both the volatilisation temperatures of the chemical constituents and their
contribution to particle hygroscopic behaviour. The resulting volatilisation and humidification tandem differential mobility analyser or VH-TDMA, has proven to be a valuable research tool which is being used in ongoing research.
Findings of investigations relating the composition of the submicrometer marine
aerosol modes to candidate models for their formation are presented. Sea salt was not
found in the numerically dominant particle type in coastal nucleation mode or marine
Aitken and accumulation modes examined on the Southeast Queensland coast during
periods where back trajectories indicated marine origin. The work suggests that all
three submicrometer modes contain the same four volatile chemical species and an
insoluble non-volatile residue. The volatility and hygroscopic behaviours of the
particles are consistent with a composition consisting of a core composed of sulfuric
acid, ammonium sulfate and an iodine oxide coated with a volatile organic compound.
The volume fraction of the sulfuric acid like species in the particles shows a strong
dependence on particle size.
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Johnson, Graham Richard. "The Formation and Growth of Marine Aerosols and the Development of New Techniques for their In-situ Analysis." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16117/.
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Marine aerosols have attracted increasing attention over the past 15 years because of their potential significance for global climate modelling. The size distribution of these aerosols extends from super-micrometer sea salt mode particles down through 150 nm accumulation mode particles, 40 nm Aitken mode particles and nucleation mode particles which extend from 25 nm right down to clusters of a few molecules. The process by which the submicrometer modes form and grow and their composition have remained topics of debate throughout this time in large part because of the difficulties associated with determining their composition and relating it to proposed models of the formation process. The work compared the modality of marine aerosol influencing the South-east-Queensland region with that of other environmental aerosols in the region. The aerosol was found to be consistent with marine aerosols observed elsewhere with concentrations below 1000 cm-3 and frequently exhibiting the distinct bimodal structure associated with cloud processing, consisting of an Aitken mode at approximately 40 nm, an accumulation mode in the range 100-200 nm and a coarse mode attributed to sea salt between 600 and 1200 nm. This work included the development of two new techniques for aerosol research. The first technique measures aerosol density using a combination of aerosol size distribution and gravimetric mass concentration measurements. This technique was used to measure the density of a number of submicrometer aerosols including laboratory generated NaCl aerosol and ambient aerosol. The densities for the laboratory generated aerosols were found to be similar to those for the bulk materials used to produce them. The technique, extended to super-micrometer particle size range may find application in ambient aerosol research where it could be used to discriminate between periods when the aerosol is dominated by NaCl and periods when the density is more representative of crustal material or sulfates. The technique may also prove useful in laboratory or industrial settings for investigating particle density or in case where the composition is known, morphology and porosity. The second technique developed, integrates the existing physicochemical techniques of volatilisation and hygroscopic growth analysis to investigate particle composition in terms of both the volatilisation temperatures of the chemical constituents and their contribution to particle hygroscopic behaviour. The resulting volatilisation and humidification tandem differential mobility analyser or VH-TDMA, has proven to be a valuable research tool which is being used in ongoing research. Findings of investigations relating the composition of the submicrometer marine aerosol modes to candidate models for their formation are presented. Sea salt was not found in the numerically dominant particle type in coastal nucleation mode or marine Aitken and accumulation modes examined on the Southeast Queensland coast during periods where back trajectories indicated marine origin. The work suggests that all three submicrometer modes contain the same four volatile chemical species and an insoluble non-volatile residue. The volatility and hygroscopic behaviours of the particles are consistent with a composition consisting of a core composed of sulfuric acid, ammonium sulfate and an iodine oxide coated with a volatile organic compound. The volume fraction of the sulfuric acid like species in the particles shows a strong dependence on particle size.
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Gawryla, Matthew Daniel. "Low Density Materials through Freeze-Drying:Clay Aerogels and Beyond…" Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1247013426.
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Lau, Bobby Wing Shun. "A complete model of the infrared dielectric function of a low-density silica aerogel /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
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Ekström, Alexander, Olof Gustafsson, Anders Kvarned, et al. "Mechanical properties dependence on microstructure in aerogel-like Quartzene®." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-226525.
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In this project the relation between pore size/porosity and the mechanical properties has been studied in the aerogel-like material Quartzene®. Quartzene® is a patented material produced by Svenska Aerogel AB. Density measurements were made on three different types of Svenska Aerogels ABs Quartzene® in the shape of pellets.These three types of Quartzene® is called CMS, ND and E9. The mechanical properties were studied by doing diametrical crush-tests on the pellets. Afterwards the samples were examined through SEM in order to study the structural properties like porosity and microstructure. By examining the materials in this order the group hoped to find a correlation between the mechanical properties and the pore size/porosity. Other microscopic analyses such as TEM and FIB was considered, but due to time limitation these methods were not used. Rough density measurements resulted in an estimated density of 0.82-0.88 g/cm3 for CMS, 0.28-0.30 g/cm3 for E9 and 0.21-0.22 g/cm3 for ND. The crush-tests resulted in a mean fracture stress of 0.81-0.89 MPa for CMS, 0.30 MPa for E9 and 0.20-0.21 MPa for ND. Studying the materials in SEM resulted in an observed mean pore size of 59-73 nm for CMS, 264-362 nm for E9 and 690-710 nm for ND in the mesoporous domain. A subtle relationship between density/pore size and fracture was obtained, with a higher density and smaller pores leading to a higher fracture stress. Due to the lack of data in this study, it is recommended though that this is something that should be examined further before any conclusions can be made. In general Quartzene® has shown to be a brittle material, but this study indicates that the mechanical properties could be controlled in somehow through the microstructure of the material, focusing on controlling the pore sizes. Further investigations in sintering of Quartzene® are also recommended in this study because of its promising effects on the mechanical properties shown in other studies.
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Jadon, Ankita. "Interactions between sodium carbonate aerosols and iodine fission-products." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R021/document.
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L’analyse de sûreté des réacteurs à neutrons rapides refroidis au sodium de Génération IV nécessite l'étude des conséquences d'un accident grave en cas de rejet dans l'environnement du sodium et des radionucléides qu'il transporte (terme source chimique et radiologique). Le terme source global dépend donc à la fois de la spéciation chimique des aérosols de sodium, issus de la combustion du sodium dans l'enceinte, et de leurs interactions avec les radionucléides. Au cours de cette thèse, les interactions entre le carbonate de sodium et les produits de fission gazeux iodés (I2 et HI) ont été étudiées aux échelles atomique et macroscopique, via une double approche théorique et expérimentale. Une expression analytique de l'isotherme d'adsorption a été développée. La stabilité relative des surfaces du carbonate de sodium a été déterminée par des calculs ab initio utilisant la théorie de la densité fonctionnelle. La réactivité de l'iode a été étudiée pour les surfaces les plus stables et les isothermes d'adsorption évaluées. En parallèle, la cinétique de capture de l'iode moléculaire par le carbonate de sodium a été déterminée expérimentalement pour différentes conditions. L'ensemble des résultats montrent une capture efficace de l'iode moléculaire par le carbonate de sodium à 373 K, variant selon la pression partielle d'iode et la surface du carbonate. Pour les conditions représentatives d'un accident grave, les sites d'adsorption de la surface de carbonate de sodium la plus favorable seront majoritairement vides ou doublement occupés selon la pression partielle d'iode moléculaire, conduisant à une pression d'équilibre inférieure à 2x10-4 bar à 373 K<br>The safety analysis of Generation IV sodium-cooled fast neutron reactors requires the study of the consequences of a severe accident in case of release into the environment of sodium and the radionuclides it carries (term chemical and radiological source). The global source term therefore depends on both the chemical speciation of sodium aerosols, resulting from the combustion of sodium in the containment, and their interactions with radionuclides. During this thesis, the interactions between sodium carbonate and iodinated gaseous fission products (I2 and HI) were studied at the atomic and macroscopic scales, via a combined theoretical and experimental approach. An analytical expression of the adsorption isotherm has been developed. The relative stability of the sodium carbonate surfaces was determined by ab initio calculations using density functional theory. The reactivity of iodine has been studied for the most stable surfaces and the adsorption isotherms evaluated. In parallel, the kinetics of capture of molecular iodine by sodium carbonate has been determined experimentally for different boundary conditions.The results show an effective capture of the molecular iodine by sodium carbonate at 373 K, varying according to the partial pressure of iodine and the surface of the carbonate sorbent. For the representative conditions of a severe accident, the adsorption sites of the most favorable sodium carbonate surfaces will be mostly bare or doubly occupied depending on the partial pressure of molecular iodine; leading to an equilibrium pressure of less than 2x10-4 bar at 373 K
Books on the topic "Aerosol density"
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Friedrich, Horez, and Lyndon B. Johnson Space Center., eds. Capture of hypervelocity particles with low-density aerogel. National Aeronautics and Space Administration, Lyndon B. Johnson Space Center, 1998.
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M, Mukhin L., Nenarokov D. F, and United States. National Aeronautics and Space Administration., eds. Preliminary results of measurements by automated probes Vega 1 and 2 of particle concentration in clouds of Venus at heights 47-63 KM. National Aeronautics and Space Administration, 1986.
Find full textBook chapters on the topic "Aerosol density"
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Oudin, Louis R. "Determination of the specific density of an aerosol through tomography." In Mathematical Methods in Tomography. Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/bfb0084522.
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Kannosto, J., A. Virtanen, T. Rönkkö, Pasi Aalto, J. Keskinen, and Markku Kulmala. "Density of Boreal Forest Aerosol Particles as a Function of Mode Diameter." In Nucleation and Atmospheric Aerosols. Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6475-3_174.
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Donovan, R. P., B. R. Locke, and D. S. Ensor. "Measuring Aerosol Particle Concentration in Clean Rooms and Particle areal Density on Silicon Wafer Surfaces." In Particles on Surfaces 1. Springer US, 1988. http://dx.doi.org/10.1007/978-1-4615-9531-1_4.
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Solomos, Stavros, and George Kallos. "Dust Production by Density Currents – A Not So Well Known Source of Aerosol Particles in the Atmosphere." In Air Pollution Modeling and its Application XXII. Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-5577-2_24.
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Matsumoto, Kiyoshi, and Mitsuo Uematsu. "Number Density and Carbon Concentration of Accumulation Mode Particles over the North Pacific Ocean." In Nucleation and Atmospheric Aerosols. Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6475-3_148.
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"Appendix H: Bulk Density of Some Common Aerosol Materials." In Aerosol Measurement. John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118001684.app8.
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Filho, Pedro I. O., Dominic B. Potter, Michael J. Powell, Claire J. Carmalt, Panagiota Angeli, and Eric S. Fraga. "Probability Density Functions for Droplet Sizing in Aerosol Transport Modelling." In Computer Aided Chemical Engineering. Elsevier, 2017. http://dx.doi.org/10.1016/b978-0-444-63965-3.50376-7.
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Ganas, George, George Karagiannakis, Aitor Eguia-Barrio, Miguel Bengoechea, Iratxe de Meatza, and Georgia Kastrinaki. "Aerosol Spray Pyrolysis Synthesis of Doped LiNi0.5Mn1.5O4 Cathode Materials for Next Generation Lithium-Ion Batteries." In Recent Perspectives in Pyrolysis Research. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.100406.
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The autonomy of next generation Electric Vehicles relies on the development of high energy density automotive batteries. LiMn1.5Ni0.5O4 (spinel structure) is a promising active cathode material in terms of charge rate capability, theoretical capacity, cost and sustainability being a cobalt-free material. In the current study pristine and doped (Fe, Al, Mg) LiMn1.5Ni0.5O4 particles were synthesized by an Aerosol Spray Pyrolysis pilot scale unit in a production rate of 100 gr. h−1 and were evaluated for their electrochemical activity in Half Coin Cell form. The doped particles were characterized in terms of their surface area, particle size distribution, crystallite size, morphology and ion insertion of the doping element into the LiNi0.5Mn1.5O4 lattice by Raman spectroscopy. The mixed oxide particles had homogeneous composition which is an inert characteristic of aerosol spray pyrolysis synthesis. The electrochemical activity of the material is attributed both to the nanoscale structure, by successful dopant ion insertion into the spinel lattice as well as to optimization of carbon and spinel particle interface contact in the microscale for increase of electrode conductivity.
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Lynch, David K., and Kenneth Sassen. "Subvisual Cirrus." In Cirrus. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195130720.003.0016.
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Starting during World War II, pilots flying high over the tropics reported “a thin layer of cirrus 500ft above us”. Yet as they ascended, they still observed more thin cirrus above them, leading to the colloquialism “cirrus evadus.” With the coming of lidar in the early 1960s, rumors and unqualified reports of subvisual cirrus were replaced with validated detections, in situ sampling, and the first systematic studies (Uthe 1977; Barnes 1980, 1982). Heymsfield (1986) described observations over Kwajalein Atoll in the western tropical Pacific Ocean, where pilots and lidars could clearly see the cloud but DMSP (U.S. Defense Meteorological Satellite Program) radiance measurements and ground observers could not. The term “subvisual” is a relatively recent appellation. Prior terminology included cirrus haze, semitransparent cirrus, subvisible cirrus veils, low density clouds, fields of ice aerosols, cirrus, anvil cirrus, and high altitude tropical (HAT) cirrus. Subvisual cirrus clouds (SVC) are widespread (Winker and Trepte 1998; see chapter 12, this volume) and virtually undetectable with existing passive sensors. Orbiting solar limb occupation systems such as the Stratospheric Aerosol and Gas Experiment (SAGE) can detect these clouds, but only by looking at them horizontally where the optical depths are significant. SVC appear to affect climate primarily by heating the planet, though to what extent this may happen is unknown. Much of what we know is based on work by Heymsfield (1986), Platt et al. (1987), Sassen et al. (1989, 1992), Flatau et al. (1990), Liou et al. (1990), Hutchinson et al. (1991, 1993), Dalcher (1992), Sassen and Cho (1992), Takano et al. (1992), Lynch (1993), Schmidt et al. (1993), Schmidt and Lynch (1995), and Winker and Trepte (1998). SVC are defined as any high clouds composed primarily of ice (WMO 1975) and whose vertical visible optical depth is 0.03 or less (Sassen and Cho 1992). Such clouds are usually found near the tropopause and are less than about 1 km thick vertically. SVC do not appear to be fundamentally different from ordinary, optically thicker cirrus. They do, however, differ from average cirrus by being colder (-50-90°C), thinner (<0.03 optical depths at 0.694 μm), and having smaller particles (typically about <50μm diameter).
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Oxtoby, David W., Vicente Talanquer, and Ari Laaksonen. "Density functional theory for binary nucleation." In Nucleation and Atmospheric Aerosols 1996. Elsevier, 1996. http://dx.doi.org/10.1016/b978-008042030-1/50003-2.
Full textConference papers on the topic "Aerosol density"
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Miyahara, Shinya, Munemichi Kawaguchi, Hiroshi Seino, Takuto Atsumi, and Masayoshi Uno. "Analytical Study on Removal Mechanisms of Cesium Aerosol From a Noble Gas Bubble Rising Through Liquid Sodium Pool (II) Effects of Particle Size Distribution and Agglomeration in Aerosols." In 2021 28th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/icone28-63286.
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Abstract In a postulated accident of fuel pin failure of sodium cooled fast reactor, a fission product cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. As the result, the xenon and krypton released with cesium aerosol into the sodium coolant as bubbles have an influence on the removal of cesium aerosol by the sodium pool in a period of bubble rising to the pool surface. In this study, cesium aerosol removal behavior due to inertial deposition, sedimentation and diffusion from a noble gas bubble rising through liquid sodium pool was analyzed by a computer program named AESOP (AErosol scrubbing in SOdium Pool) which deals with the expansion and the deformation of the bubble together with the aerosol absorption considering the effects of particle size distribution and agglomeration in aerosols. In the analysis, initial bubble diameter, sodium pool depth and temperature, aerosol particle diameter and density, initial aerosol concentration in the bubble were changed as parameter, and the results for the sensitivities of these parameters on decontamination factor (DF) of cesium aerosol were compared with the results of the previous study in which the effects of particle size distribution and agglomeration in aerosols were not considered. From the results, it was concluded that the sensitivities of initial bubble diameter, the aerosol particle diameter and density to the DF became significant due to the inertial deposition of agglomerated aerosols. To validate these analysis results, the simulation experiments have been conducted using a simulant particles of cesium aerosol under the condition of room temperature in water pool and air bubble systems. The experimental results will be compared with the analysis results calculated under the same condition in the near future.
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Schroeder, Steven, Bernhard Stiehl, Juanpablo Delgado, Rajendra Shrestha, Michael Kinzel, and Kareem Ahmed. "Interactions of Aerosol Droplets With Ventilated Airflows in the Context of Airborne Pathogen Transmission." In ASME 2022 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/fedsm2022-87739.
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Abstract This multidisciplinary study provides a comprehensive visualization of airborne aerosols and droplets coming into contact with crossflows of moving air utilizing both experimental particle measuring methods and multiphase computational fluids dynamics (CFD). The aim of this research is to provide a Eulerian visualization of how these crossflows alter the position and density of an aerosol cloud, with the goal of applying this information to our understanding of social distancing ranges within outdoor settings and ventilated rooms. The results indicate that even minor perpendicular crossflows across the trajectory of an aerosol cloud can greatly reduce both the linear displacement and density of the cloud, with negligible increases in density along the flow path.
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Koie, Ryusuke, Munemichi Kawaguchi, Shinya Miyahara, Masayoshi Uno, and Hiroshi Seino. "A Study on Removal Mechanisms of Cesium Aerosol From Noble Gas Bubble in Sodium Pool (III) Measurement of Decontamination Factors in Water Simulation Test." In 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-94057.
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Abstract In a postulated accident of fuel pin failure of a sodium-cooled fast reactor, a fission product of cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. The xenon and krypton released with the cesium aerosols into the sodium coolant as bubbles have an influence on the removal of cesium aerosols by the sodium pool in a period of bubble rising to the sodium pool surface. Then, the cesium aerosols could transfer into the containment vessel as an initial inventory of a source term. To meet this target, we have developed the computer program AESOP that deals with the expansion and the deformation of the bubble together with the aerosol absorption and researched the sensitivities of the physical parameters on decontamination factor (DF) of cesium aerosols such as the initial bubble diameter, sodium pool depth, and temperature, aerosol particle diameter, and density, initial aerosol concentration in the bubble in previous our papers. In this study, we performed a water simulation test to measure the DFs of simulant aerosols with nitrogen gas bubbles rising through the water pool for the code validation. The experiments revealed that the DFs increased with the increase in the aerosol diameter and the water pool depth.
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Ersahin, C., I. B. Celik, W. G. Lindsley, and D. G. Frazer. "Aerosol Generation and Entrainment Model for Cough Simulations." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98100.
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Coughing produces aerosols comprised of components of fluid that line the respiratory tract. These aerosols have been implicated in the transmission of many infectious diseases. Important factors that must be considered in aerosol transport include its physical size distribution, the shape and density of its components, as well as its chemical and biological composition. This study represents the initial phase of a larger project whose goal is to investigate the relationship between the generation of infectious aerosols and the dissemination of diseases in the workplace. The objective of this study was to develop a computational model representative of the generation and entrainment of an aerosol during cough. This model is composed of two sub-models; the first describes the formation of “mother” droplets and their entrainment in an air-stream and the second simulates the fragmentation of these droplets into smaller size distributions. The first sub-model is used to calculate the amount of fluid entrained in the droplets which is a function of the physical properties of the airway lining fluid and airflow patterns in the airway. The second sub-model describes the fragmentation of the droplets as a function of the physical properties of the fluid composition and a description of the flow field surrounding the droplet. Preliminary results show that, with the proper choice of model constants, it is possible to obtain relatively good agreement between model predictions and experimental measurements.
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Rudiger, Joshua J., John S. deGrassie, Kevin McBryde, and Stephen Hammel. "Predicting atmospheric aerosol size distributions using Mixture Density Networks." In SPIE Optical Engineering + Applications, edited by Alexander M. J. van Eijk, Christopher C. Davis, and Stephen M. Hammel. SPIE, 2015. http://dx.doi.org/10.1117/12.2189931.
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Cazier, Laurent, Colette Brogniez, Jacqueline Lenoble, and Claude Devaux. "Inference of aerosol size distribution, surface area density, and volume density from multispectral extinction measurements." In Aerospace Remote Sensing '97, edited by Joanna D. Haigh. SPIE, 1997. http://dx.doi.org/10.1117/12.301155.
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Miyahara, Shinya, Munemichi Kawaguchi, and Hiroshi Seino. "Analytical Study on Removal Mechanisms of Cesium Aerosol From a Noble Gas Bubble Rising Through Liquid Sodium Pool." In 2020 International Conference on Nuclear Engineering collocated with the ASME 2020 Power Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/icone2020-16208.
Full textAbstract:
Abstract In a postulated accident of fuel pin failure of sodium cooled fast reactor, a fission product cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. As the result, the xenon and krypton released with cesium aerosol into the sodium coolant as bubbles have an influence on the removal of cesium aerosol by the sodium pool in a period of bubble rising to the pool surface. In this study, cesium aerosol removal behavior due to inertial deposition, sedimentation and diffusion from a noble gas bubble rising through liquid sodium pool was analyzed by constructing a computer program which deals with the expansion and the deformation of the bubble together with the aerosol absorption. In the analysis, initial bubble diameter, sodium pool depth and temperature, aerosol particle diameter and density, initial aerosol concentration in the bubble were changed as parameter, and the sensitivities of these parameters on decontamination factor (DF) of cesium aerosol were investigated. From the results, it was concluded that the initial bubble diameter was most sensitive parameter to the DF of cesium aerosol in the rising bubble due to the inertial deposition. It was found that the sodium pool depth, the aerosol particle diameter and density have also important effect on the DF of cesium aerosol, but the sodium temperature has a marginal effect on the DF. To meet these results, the experiments for the investigation of cesium aerosol absorption behavior from rising noble gas bubble through sodium pool are under planning to validate the results for the sensitivities of above-mentioned parameters on the DF of cesium aerosol in the analysis.
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Fastig, Shlomo, Y. Benayahu, Abraham Englander, and E. Glaser. "Aerosol density distribution in the boundary layer measured by a scanning LIDAR system." In 8th Meeting in Israel on Optical Engineering, edited by Moshe Oron, Itzhak Shladov, and Yitzhak Weissman. SPIE, 1993. http://dx.doi.org/10.1117/12.151028.
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Xue, Yanqun, Hideo Tashiro, Katsutaro Ando, Hiroaki Kuze, and Nobuo Takeuchi. "Simultaneous observation of NO2 column density and aerosol optical thickness in Kanto area, Japan." In Second International Asia-Pacific Symposium on Remote Sensing of the Atmosphere, Environment, and Space, edited by Yasuhiro Sasano, Jinxue Wang, and Tadahiro Hayasaka. SPIE, 2001. http://dx.doi.org/10.1117/12.416986.
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Wang, Shanpu, Yuxiang Li, Liwen He, Lili Tong, and Xuewu Cao. "Experimental Study on Aerosol Penetration Through Concrete Cracks Under Inertial Collision and Steam Condensation." In 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-90512.
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Abstract Estimation of aerosol penetration through the cracked concrete wall with a submillimeter height has attracted more attention for radioactivity optimization evaluation of containment, which emphasizes the aerosol deposition inside the cracks without catastrophic destruction of containment. While, no deposition has been considered in current radiological assessments and the penetration of aerosol is simply assumed to be released as the leakage of gas. Therefore, the results of assessment are too conservation for the leakage of radioactive aerosol without considering any deposition. In this work, an experimental facility is set up to study the penetration of particles through cracked concrete walls with different geometric dimensions. Titanium dioxide powder is chosen due to its density and nontoxicity. A sampling system is designed for the measurement of aerosol concentration under high temperature and containing condensable steam. One regular concrete crack in the shape of a straight rectangular slot and one irregular concrete crack with different streamwise tortuosities, τ, which is defined as the radio of the actual length of a crack pathway and the thickness of concrete structure, have been used in the tests of gas leakage and aerosol exposure. The height of cracks can be calculated from the consequences of gas leakage characteristic, based on the Suzuki’s flow model. Research results of aerosol exposure tests indicate that increasing the flow rate, particle diameter and tortuosity all can enhance the aerosol penetration, and micron particles cannot penetrate concrete cracks, compared with submicron particles. The aerosol penetration through the straight concrete crack is in good agreement with the prediction by the correlation proposed by Van De Vate, but no agreement is reached for the irregular crack with some tortuosity. Meantime, the effect of steam condensation on aerosol penetration is also been discussed preliminarily.
Reports on the topic "Aerosol density"
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Kesavan, Jana, and Robert W. Doherty. Density Measurements of Materials Used in Aerosol Studies. Defense Technical Information Center, 2000. http://dx.doi.org/10.21236/ada384063.
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Ruiz, D. E., and Nathaniel Fisch. Aerodynamic Focusing Of High-Density Aerosols. Office of Scientific and Technical Information (OSTI), 2014. http://dx.doi.org/10.2172/1129015.
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Hotaling, S. P. Ultra-Low Density Aerogel Mirror Substrates. Defense Technical Information Center, 1993. http://dx.doi.org/10.21236/ada266128.
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Hrubesh, L. Development of low density silica aerogel as a capture medium for hyper-velocity particles. Office of Scientific and Technical Information (OSTI), 1989. http://dx.doi.org/10.2172/5362334.
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