Here, we use a variety of microscopic imaging techniques, including scanning electron microscopy, 3D visible light microscopy, and portable microscopy to capture the topography of rough paper. Paper coated with a model soot was cleaned with either a firm vinyl eraser or softer, putty-like kneaded eraser and reimaged to characterize the disposition of remaining soot. Although both methods remove soot from the upper-most surface of the paper, only the kneaded eraser can conform to the complex topography to remove soot from the interstices between paper fibers.

Organic residues preserved on the outer surfaces of archaeological pottery are commonly considered to be soot and, not being subject to reservoir effects, as more reliable for radiocarbon (14C) dating compared to food crusts from the inner surface. However, unlike food crusts, outer surface residues are never analyzed prior to 14C dating. This study confronts 14C dates on inner and outer surface residues preserved on prehistoric pottery from Bazel Sluis (Belgium) with the results of stable isotope analysis and thermally assisted hydrolysis and methylation pyrolysis-gas chromatography-mass spectrometry (THM-GC-MS). These analyses clearly show that food residue is also present on the outer pottery surface, causing a possible reservoir effect on 14C dates. At Bazel, 14C dates on both the inner and outer surface residues are too old compared to dates obtained on associated animal bone. In addition, the outer surface residues systematically date younger than the inner food crusts, a discrepancy that is also known from other archaeological sites. It is suggested that these age differences are due to the mixed presence of soot and food residue on the exterior vessel wall as opposed to more homogeneous food crusts on the internal surface.

Astronomical observations of Centaurs and trans-Neptunian objects (TNOs) yield two characteristic features – near-infrared (NIR) reflectance and low geometric albedo. The first feature apparently originates due to complex organic material on their surfaces, but the origin of the material contributing to low albedo is not well understood. Titan tholins synthesized to simulate aerosols in the atmosphere of Saturn's moon Titan have also been used for simulating the NIR reflectances of several Centaurs and TNOs. Here, we report novel detections of large polycyclic aromatic hydrocarbons, nanoscopic soot aggregates and cauliflower-like graphite within Titan tholins. We put forth a proof of concept stating the surfaces of Centaurs and TNOs may perhaps comprise of highly ‘carbonized’ complex organic material, analogous to the tholins we investigated. Such material would apparently be capable of contributing to the NIR reflectances and to the low geometric albedos simultaneously.

Monochromated electron energy-loss spectroscopy (EELS) is employed to determine the optical properties of carbonaceous aerosols from the infrared to the ultraviolet region of the spectrum. It is essential to determine their optical properties to understand their accurate contribution to radiative forcing for climate change. The influence of surface and interface plasmon effects on the accuracy of dielectric data determined from EELS is discussed. Our measurements show that the standard thin film formulation of Kramers−Kronig analysis can be employed to make accurate determination of the dielectric function for carbonaceous particles down to about 40 nm in size. The complex refractive indices of graphitic and amorphous carbon spherules found in the atmosphere were determined over the wavelength range 200–1,200 nm. The graphitic carbon was strongly absorbing black carbon, whereas the amorphous carbon shows a more weakly absorbing brown carbon profile. The EELS approach provides an important tool for exploring the variation in optical properties of atmospheric carbon.

Le besoin d'un critère d'inflammabilité des matériaux est avéré dès lorsque la sécurité-incendie des engins spatiaux habités est envisagée.Différentes limites du nombre de transfert de masse apparaissentessentielles pour définir ce critère. Cependant, l'estimationde l'indice de confiance en ce critère requiert la connaissance de l'incertitudeliée aux transferts radiatifs, encore mal connus en micropesanteur.Afin de découpler les phénomènes de pyrolyse et de dégagement dechaleur, une flamme non-prémélangée d'éthylène a été étudiée en micropesanteur.L'absorption radiative par la couche de suie formée représente la premièreétape de la caractérisation des phénomènes radiatifs. L'émission spontanéedes radicaux CH* précise alors la zone de réaction tridimensionnelle.Une mesure par extinction laser permet d'y corréler le champ d'absorption des suies.L'évolution spectrale de l'épaisseur optique de la couche de suie est ainsi déduite.