Simulated Annealing as a Method for the Determination of the Spatial Distribution of a Condensable Adsorbate in Mesoporous Materials

Langmuir ◽  
2003 ◽  
Vol 19 (8) ◽  
pp. 3333-3337 ◽  
Author(s):  
M. E. Kainourgiakis ◽  
E. S. Kikkinides ◽  
G. Ch. Charalambopoulou ◽  
A. K. Stubos
Keyword(s):  
Spatial Distribution ◽  
Simulated Annealing ◽  
Mesoporous Materials

scholarly journals Quantitative Determination of the Surface Distribution of Supported Metal Nanoparticles: A Laser Ablation–ICP–MS Based Approach

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 77
Author(s):  
Davide Spanu ◽  
Gilberto Binda ◽  
Marcello Marelli ◽  
Laura Rampazzi ◽  
Sandro Recchia ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Laser Ablation ◽  
Quantitative Determination ◽  
Metal Nanoparticles ◽  
Total Mass ◽  
Functional Materials ◽  
Metal Extraction ◽  
Ms Analysis ◽  
Icp Ms

A laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) based method is proposed for the quantitative determination of the spatial distribution of metal nanoparticles (NPs) supported on planar substrates. The surface is sampled using tailored ablation patterns and the data are used to define three-dimensional functions describing the spatial distribution of NPs. The volume integrals of such interpolated surfaces are calibrated to obtain the mass distribution of Ag NPs by correlation with the total mass of metal as determined by metal extraction and ICP–MS analysis. Once this mass calibration is carried out on a sacrificial sample, quantifications can be performed over multiple samples by a simple micro-destructive LA–ICP–MS analysis without requiring the extraction/dissolution of metal NPs. The proposed approach is here tested using a model sample consisting of a low-density polyethylene (LDPE) disk decorated with silver NPs, achieving high spatial resolution over cm2-sized samples and very high sensitivity. The developed method is accordingly a useful analytical tool for applications requiring both the total mass and the spatial distribution of metal NPs to be determined without damaging the sample surface (e.g., composite functional materials and NPs, decorated catalysts or electrodic materials).

scholarly journals The seven sisters DANCe

2018 ◽  
Vol 612 ◽  
pp. A70 ◽  
Author(s):  
J. Olivares ◽  
E. Moraux ◽  
L. M. Sarro ◽  
H. Bouy ◽  
A. Berihuete ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Model Comparison ◽  
Precise Determination ◽  
Model Parameters ◽  
Data Sets ◽  
Adequate Model ◽  
Comparison Results ◽  
Bayesian Evidence ◽  
Mass Segregation

Context. Membership analyses of the DANCe and Tycho + DANCe data sets provide the largest and least contaminated sample of Pleiades candidate members to date. Aims. We aim at reassessing the different proposals for the number surface density of the Pleiades in the light of the new and most complete list of candidate members, and inferring the parameters of the most adequate model. Methods. We compute the Bayesian evidence and Bayes Factors for variations of the classical radial models. These include elliptical symmetry, and luminosity segregation. As a by-product of the model comparison, we obtain posterior distributions for each set of model parameters. Results. We find that the model comparison results depend on the spatial extent of the region used for the analysis. For a circle of 11.5 parsecs around the cluster centre (the most homogeneous and complete region), we find no compelling reason to abandon King’s model, although the Generalised King model introduced here has slightly better fitting properties. Furthermore, we find strong evidence against radially symmetric models when compared to the elliptic extensions. Finally, we find that including mass segregation in the form of luminosity segregation in the J band is strongly supported in all our models. Conclusions. We have put the question of the projected spatial distribution of the Pleiades cluster on a solid probabilistic framework, and inferred its properties using the most exhaustive and least contaminated list of Pleiades candidate members available to date. Our results suggest however that this sample may still lack about 20% of the expected number of cluster members. Therefore, this study should be revised when the completeness and homogeneity of the data can be extended beyond the 11.5 parsecs limit. Such a study will allow for more precise determination of the Pleiades spatial distribution, its tidal radius, ellipticity, number of objects and total mass.

Sign in / Sign up

Export Citation Format

Share Document