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Journal articles on the topic 'Optical physical characterisation'

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Author: Grafiati

Published: 14 March 2023

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1

Dowd, A., D. Llewellyn, R. G. Elliman, B. Luther-Davies, M. Samoc, and J. D. Fitz Gerald. "Physical and optical characterisation of Ge-implanted silica." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 175-177 (April 2001): 637–40. http://dx.doi.org/10.1016/s0168-583x(00)00536-x.

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Zhang, Shu, Lachlan J. Gibson, Alexander B. Stilgoe, Timo A. Nieminen, and Halina Rubinsztein-Dunlop. "Impact of complex surfaces on biomicrorheological measurements using optical tweezers." Lab on a Chip 18, no. 2 (2018): 315–22. http://dx.doi.org/10.1039/c7lc01176h.

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3

D'Silva, C., Xiao-Bo Wang, and R. Pethig. "Physical and electrochemical characterisation of polyvinylferrocene films." Journal of Physics D: Applied Physics 22, no. 11 (November 14, 1989): 1591–97. http://dx.doi.org/10.1088/0022-3727/22/11/004.

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4

Moore, Lee J., Michael D. Summers, and Grant A. D. Ritchie. "Optical trapping and spectroscopic characterisation of ionic liquid solutions." Physical Chemistry Chemical Physics 15, no. 32 (2013): 13489. http://dx.doi.org/10.1039/c3cp50895a.

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5

Al Muhammadi, N. A. S., and A. Hussin. "Physical and mineral characterisation of natural zeolites from Taiz, South-western Yemen." Journal of Environmental Biology 42, no. 3(SI) (May 31, 2021): 744–49. http://dx.doi.org/10.22438/jeb/42/3(si)/jeb-02.

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Aim: To investigate the physical, minerals and geochemical composition of Taiz natural zeolites. Methodology: Each zeolite sample were assessed for its characterization via optical microscopy, X-ray Diffraction (XRD) techniques, X-ray Fluorescence Methods (XRF), Inductively Coupled Plasma- Optical Emission Spectrometry (ICP-OES) to examine their mineral composition and geochemistry properties. Further, physical properties like pH, electrical conductivity (EC), plasticity, specific surface area, water content and brightness were estimated by standard methods. Results: Natural zeolite in the studied area occurs within pyroclast of volcanic tuffs. It consists mainly of perlite and rhyolite as lenses grey to light green in color with fine granulation texture. Petrography analysis showed that the Taiz zeolites are mainly classified as clinoptilolite – heulandite and are mixed with various types of others zeolite minerals such as analcime, chabazite and mazzite. Small amounts of impurities like K-.feldspar (orthoclase) and clay mineral such as montmorillonite, kaolinite and illite were also detected. The mean ratio of SiO2:Al2O3 for representative zeolite sample from the study area ranged between of 6.34-6.98. Interpretation: Zeolites showed fairly medium to high brightness and on comparing with the commercial zeolites, Taiz zeolite showed significant industrial potential to be used as a filler in paper industry.

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Yao, Eric, Francesco Papoff, and Gian-Luca Oppo. "Characterisation of spatio-temporal complexity in optical experiments." Optics Communications 155, no. 1-3 (October 1998): 73–78. http://dx.doi.org/10.1016/s0030-4018(98)00369-1.

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7

De Sanctis, Adolfo, Jake Mehew, Monica Craciun, and Saverio Russo. "Graphene-Based Light Sensing: Fabrication, Characterisation, Physical Properties and Performance." Materials 11, no. 9 (September 18, 2018): 1762. http://dx.doi.org/10.3390/ma11091762.

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Graphene and graphene-based materials exhibit exceptional optical and electrical properties with great promise for novel applications in light detection. However, several challenges prevent the full exploitation of these properties in commercial devices. Such challenges include the limited linear dynamic range (LDR) of graphene-based photodetectors, the lack of efficient generation and extraction of photoexcited charges, the smearing of photoactive junctions due to hot-carriers effects, large-scale fabrication and ultimately the environmental stability of the constituent materials. In order to overcome the aforementioned limits, different approaches to tune the properties of graphene have been explored. A new class of graphene-based devices has emerged where chemical functionalisation, hybridisation with light-sensitising materials and the formation of heterostructures with other 2D materials have led to improved performance, stability or versatility. For example, intercalation of graphene with FeCl 3 is highly stable in ambient conditions and can be used to define photo-active junctions characterized by an unprecedented LDR while graphene oxide (GO) is a very scalable and versatile material which supports the photodetection from UV to THz frequencies. Nanoparticles and quantum dots have been used to enhance the absorption of pristine graphene and to enable high gain thanks to the photogating effect. In the same way, hybrid detectors made from stacked sequences of graphene and layered transition-metal dichalcogenides enabled a class of devices with high gain and responsivity. In this work, we will review the performance and advances in functionalised graphene and hybrid photodetectors, with particular focus on the physical mechanisms governing the photoresponse, the performance and possible future paths of investigation.

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Holzer, W., A. Penzkofer, S. Schrader, and B. Grimm. "Photo-physical and lasing characterisation of a polyparaphenylenevinylene (PPV) neat film." Optical and Quantum Electronics 37, no. 5 (April 2005): 475–94. http://dx.doi.org/10.1007/s11082-005-4225-2.

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Singh, Deepa, and K. K. Bamzai. "Preparation, Structural, Optical, Electrical, and Magnetic Characterisation of Orthorhombic GdCr0.3Mn0.7O3 Multiferroic Nanoparticles." Zeitschrift für Naturforschung A 72, no. 1 (January 1, 2017): 87–95. http://dx.doi.org/10.1515/zna-2016-0284.

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AbstractIn this article, chromium-doped gadolinium manganate (GdCr0.3Mn0.7O3) nanoparticles has been prepared by wet-chemical route in order to investigate their structural, optical, electrical, and room temperature magnetic properties. Microstructural and compositional analyses have been carried out by X-ray diffraction and scanning electron microscopy (SEM). Synthesised material is found to be in orthorhombic crystal structure with Pbnm space group. The spherical morphology of the nanoparticles has been examined from the SEM images. Functional groups have been identified using Fourier transform infrared spectroscopy. Dielectric constant, dielectric loss, AC conductivity (σac), and activation energy in the range of 1 kHz–1 MHz from room temperature to high temperature (400°C) have been investigated. The frequency dependence of AC conductivity obeys the universal power law. The value of activation energy depends on increase in frequency. Room temperature magnetic behaviour suggests the material to be paramagnetic in nature.

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Relinque, J., A. de León, J. Hernández-Saz, M. García-Romero, Francisco Navas-Martos, G. Morales-Cid, and S. Molina. "Development of Surface-Coated Polylactic Acid/Polyhydroxyalkanoate (PLA/PHA) Nanocomposites." Polymers 11, no. 3 (March 1, 2019): 400. http://dx.doi.org/10.3390/polym11030400.

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This work reports on the design and development of nanocomposites based on a polymeric matrix containing biodegradable Polylactic Acid (PLA) and Polyhydroxyalkanoate (PHA) coated with either Graphite NanoPlatelets (GNP) or silver nanoparticles (AgNP). Nanocomposites were obtained by mechanical mixing under mild conditions and low load contents (<0.10 wt %). This favours physical adhesion of the additives onto the polymer surface, while the polymeric bulk matrix remains unaffected. Nanocomposite characterisation was performed via optical and focused ion beam microscopy, proving these nanocomposites are selectively modified only on the surface, leaving bulk polymer unaffected. Processability of these materials was proven by the fabrication of samples via injection moulding and mechanical characterisation. Nanocomposites showed enhanced Young modulus and yield strength, as well as better thermal properties when compared with the unmodified polymer. In the case of AgNP coated nanocomposites, the surface was found to be optically active, as observed in the increase of the resolution of Raman spectra, acquired at least 10 times, proving these nanocomposites are promising candidates as surface enhanced Raman spectroscopy (SERS) substrates.

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Strandgren, Johan, Jennifer Fricker, and Luca Bugliaro. "Characterisation of the artificial neural network CiPS for cirrus cloud remote sensing with MSG/SEVIRI." Atmospheric Measurement Techniques 10, no. 11 (November 14, 2017): 4317–39. http://dx.doi.org/10.5194/amt-10-4317-2017.

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Abstract. Cirrus clouds remain one of the key uncertainties in atmospheric research. To better understand the properties and physical processes of cirrus clouds, accurate large-scale observations from satellites are required. Artificial neural networks (ANNs) have proved to be a useful tool for cirrus cloud remote sensing. Since physics is not modelled explicitly in ANNs, a thorough characterisation of the networks is necessary. In this paper the CiPS (Cirrus Properties from SEVIRI) algorithm is characterised using the space-borne lidar CALIOP. CiPS is composed of a set of ANNs for the cirrus cloud detection, opacity identification and the corresponding cloud top height, ice optical thickness and ice water path retrieval from the imager SEVIRI aboard the geostationary Meteosat Second Generation satellites. First, the retrieval accuracy is characterised with respect to different land surface types. The retrieval works best over water and vegetated surfaces, whereas a surface covered by permanent snow and ice or barren reduces the cirrus detection ability and increases the retrieval errors for the ice optical thickness and ice water path if the cirrus cloud is thin (optical thickness less than approx. 0.3). Second, the retrieval accuracy is characterised with respect to the vertical arrangement of liquid, ice clouds and aerosol layers as derived from CALIOP lidar data. The CiPS retrievals show little interference from liquid water clouds and aerosol layers below an observed cirrus cloud. A liquid water cloud vertically close or adjacent to the cirrus clearly increases the average retrieval errors for the optical thickness and ice water path, respectively, only for thin cirrus clouds with an optical thickness below 0.3 or ice water path below 5.0 g m−2. For the cloud top height retrieval, only aerosol layers affect the retrieval error, with an increased positive bias when the cirrus is at low altitudes. Third, the CiPS retrieval error is characterised with respect to the properties of the investigated cirrus cloud (ice optical thickness and cloud top height). On average CiPS can retrieve the cirrus cloud top height with a relative error around 8 % and no bias and the ice optical thickness with a relative error around 50 % and bias around ±10 % for the most common combinations of cloud top height and ice optical thickness. Similarities with physically based retrieval methods are evident, which implies that even though the retrieval methods differ in the implementation of physics in the model, the retrievals behave similarly due to physical constraints. Finally, we also show that the ANN retrievals have a low sensitivity to radiometric noise in the SEVIRI observations. For optical thickness and ice water path the relative uncertainty due to noise is less than 10 % down to sub-visual cirrus. For the cloud top height retrieval the uncertainty due to noise is around 100 m for all cloud top heights.

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12

Kupiszewski, P., E. Weingartner, P. Vochezer, A. Bigi, B. Rosati, M. Gysel, M. Schnaiter, and U. Baltensperger. "The Ice Selective Inlet: a novel technique for exclusive extraction of pristine ice crystals in mixed-phase clouds." Atmospheric Measurement Techniques Discussions 7, no. 12 (December 12, 2014): 12481–515. http://dx.doi.org/10.5194/amtd-7-12481-2014.

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Abstract. Climate predictions are affected by high uncertainties partially due to an insufficient knowledge of aerosol-cloud interactions. One of the poorly understood processes is formation of mixed-phase clouds (MPCs) via heterogeneous ice nucleation. Field measurements of the atmospheric ice phase in MPCs are challenging due to the presence of supercooled liquid droplets. The Ice Selective Inlet (ISI), presented in this paper, is a novel inlet designed to selectively sample pristine ice crystals in mixed-phase clouds and extract the ice residual particles contained within the crystals for physical and chemical characterisation. Using a modular setup composed of a cyclone impactor, droplet evaporation unit and pumped counterflow virtual impactor (PCVI), the ISI segregates particles based on their inertia and phase, exclusively extracting small ice particles between 5 and 20 μm in diameter. The setup also includes optical particle spectrometers for analysis of the number size distribution and shape of the sampled hydrometeors. The novelty of the ISI is a droplet evaporation unit, which separates liquid droplets and ice crystals in the airborne state, thus avoiding physical impaction of the hydrometeors and limiting potential artifacts. The design and validation of the droplet evaporation unit is based on modelling studies of droplet evaporation rates and computational fluid dynamics simulations of gas and particle flows through the unit. Prior to deployment in the field, an inter-comparison of the WELAS optical particle size spectrometers and a characterisation of the transmission efficiency of the PCVI was conducted in the laboratory. The ISI was subsequently deployed during the Cloud and Aerosol Characterisation Experiment (CLACE) 2013 – an extensive international field campaign encompassing comprehensive measurements of cloud microphysics, as well as bulk aerosol, ice residual and ice nuclei properties. The campaign provided an important opportunity for a proof of concept of the inlet design. In this work we present the setup of the ISI, including the modelling and laboratory characterisation of its components, as well as a case study demonstrating the ISI performance in the field during CLACE 2013.

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13

Kemp, Terence J. "The Aryl Cation – the Trapping and Characterisation of a Hyper-Reactive Species." Progress in Reaction Kinetics and Mechanism 28, no. 1 (March 2003): 11–34. http://dx.doi.org/10.3184/007967403103165431.

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The article traces the development of the epr and optical spectroscopic characterisation and progressive theoretical understanding of the aryl cation, starting from the initial cryogenic epr study of 2,5-dialkoxyl-4-morpholinophenyl cation, which defined unambiguously its triplet state character, through simple MO, ab initio and DFT calculations on substituted aryl cations, to picosecond laser photolysis studies in fluorinated solvents, noting especially the early and vital contribution of Martyn Symons.

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Antoniow, Jean-Stéphane, Jean-François Henry, Michel Egée, and Mihai Chirtoc. "Noncontact photopyroelectric (PPE) method for the thermo-optical characterisation of layered samples." High Temperatures-High Pressures 29, no. 5 (1997): 549–54. http://dx.doi.org/10.1068/htec133.

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Kalus, Gregor, André Mensing, and Bruno Bein. "Photothermal characterisation of the structural and optical effects of plasma-sprayed coatings." High Temperatures-High Pressures 30, no. 5 (1998): 537–45. http://dx.doi.org/10.1068/htec93.

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16

Kinnell, P. K., M. C. L. Ward, and R. Craddock. "Physical characterisation of selective stress coupling for resonant pressure sensors." Sensors and Actuators A: Physical 115, no. 2-3 (September 2004): 230–34. http://dx.doi.org/10.1016/j.sna.2004.01.061.

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17

Bhushan, Binay. "Preparation and characterisation of smart polymer-metal nanocomposite: optical and morphological study." International Journal of Nano and Biomaterials 7, no. 3 (2018): 219. http://dx.doi.org/10.1504/ijnbm.2018.094250.

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Bhushan, Binay. "Preparation and characterisation of smart polymer-metal nanocomposite: optical and morphological study." International Journal of Nano and Biomaterials 7, no. 3 (2018): 219. http://dx.doi.org/10.1504/ijnbm.2018.10015468.

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19

Melvi Chandy and K. Shreekrishna Kumar. "Characterisation of Silver Deposited Coir Fibers by Magnetron Sputtering." CORD 31, no. 1 (April 1, 2015): 7. http://dx.doi.org/10.37833/cord.v31i1.67.

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Silver thin films are extensively used due to their superior optical, electrical and antimicrobial properties. Recent development in the incorporation silver thin films on natural fibers makes it possible to utilize its excellent physical and chemical properties in the field of textiles. Present study focuses on the surface functionalization of natural coir fiber with silver thin film by magnetron sputtering. This will help to widen the use of natural coir fibers. The surface morphology of the coated coir fibers are investigated by employing a scanning electron microscope. The results show that the surface functionalization of silver-coated coir fibers are highly versatile, and it possess excellent protection against ultraviolet radiation, exhibit excellent hydrophobicity (contact angle=105.2°) and good antibacterial effects. This study demonstrates that treatment, which uses silver thin films by magnetron sputtering, is a promising method for achieving multifunctional coir fabrics.

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20

Barrow, M. S., R. L. Jones, J. O. Park, M. Srinivasarao, P. R. Williams, and C. J. Wright. "Physical characterisation of microporous and nanoporous polymer films by atomic force microscopy, scanning electron microscopy and high speed video microphotography." Spectroscopy 18, no. 4 (2004): 577–85. http://dx.doi.org/10.1155/2004/526415.

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We report studies of ordered microporous and nanoporous polymer films formed by the evaporation of polymer solutions following exposure to a humid atmosphere. High speed microphotographic (HSMP) studies of the formation process showed that near the surface of the polymer solution, vapour condensation produced near mono-disperse water droplets which form a close-packed monolayer (or ‘breath figure’). Following the evaporation of the solvent, characterisation of the solid by Atomic Force Microscopy and Scanning Electron Microscopy revealed that the surface of the polymer film is characterised by extensive regions of hexagonally close-packed microscopic pores, whose spatial arrangement replicates that of the initial droplet monolayer. Characterisation of sections of the film by Atomic Force Microscopy established that the surficial pores represent open sections of sub-surficial spheroidal cavities formed by encapsulation of the water droplets within the polymer solution. An interesting feature of the results is the occurrence of nano-scale pores at the film surface and at (and within) the walls of the sub-surficial microscopic pores. This is the first physical evidence report of such features in porous polymer films produced by a process involving breath-figures. Their dimensions suggest that more detailed structural investigations will require alternative techniques to conventional, optical methods.

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Planells, Miquel, Luke X. Reynolds, Umesh Bansode, Shraddha Chhatre, Satishchandra Ogale, Neil Robertson, and Saif A. Haque. "Synthesis and optical characterisation of triphenylamine-based hole extractor materials for CdSe quantum dots." Physical Chemistry Chemical Physics 15, no. 20 (2013): 7679. http://dx.doi.org/10.1039/c3cp50980j.

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Bansal, A. K., and A. Penzkofer. "Linear and nonlinear optical spectroscopic characterisation of triphenylamine and 1,2,3-tris(3-methylphenylphenylamino)benzene." Chemical Physics 352, no. 1-3 (September 2008): 48–56. http://dx.doi.org/10.1016/j.chemphys.2008.05.006.

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23

Ghosh, S., S. Osborne, and M. H. Smith. "On the importance of cumulus penetration on the microphysical and optical properties of stratocumulus clouds." Atmospheric Chemistry and Physics Discussions 4, no. 4 (August 20, 2004): 4611–40. http://dx.doi.org/10.5194/acpd-4-4611-2004.

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Abstract. Owing to their extensive spatial coverage, stratocumulus clouds play a crucial role in the radiation budget of the earth. Climate models need an accurate characterisation of stratocumulus in order to provide an accurate forecast. However, remote sensing as well as in-situ observations reveal that on several occasions, cumulus clouds present below the stratocumulus, often have a significant impact on the main stratocumulus microphysical properties. This was observed during the ACE-2 (Aerosol Characterisation Experiment 2) campaign designed to study the impact of polluted continental air on stratocumulus formation. In this paper we used a detailed micro-physical chemical parcel model to quantify the extent of this cumulus-stratocumuls coupling. In addition, we made extensive use of microphysical observations from the C-130 aircraft that was operated during ACE-2. For the ACE-2 case studies considered in this paper, our analysis revealed that the chemical, microphysical and optical characteristics of the main stratocumulus cloud deck had significant contributions from cumulus clouds that often penetrated the stratocumulus deck. The amount of fine mode ionic species, the average droplet number concentrations, the effective radii and the optical depths during the flight A562 (when cumulus clouds interacted with the main stratocumulus) were estimated and model runs that included this effect yielded microphysical and optical properties which compared more favourably with the observations than the runs which did not. This study highlights the importance of including these cumulus effects in stratocumulus related modelling studies.

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Ghosh, S., S. Osborne, and M. H. Smith. "On the importance of cumulus penetration on the microphysical and optical properties of stratocumulus clouds." Atmospheric Chemistry and Physics 5, no. 3 (March 7, 2005): 755–65. http://dx.doi.org/10.5194/acp-5-755-2005.

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Abstract. Owing to their extensive spatial coverage, stratocumulus clouds play a crucial role in the radiation budget of the earth. Climate models need an accurate characterisation of stratocumulus in order to provide an accurate forecast. However, remote sensing as well as in-situ observations reveal that on several occasions, cumulus clouds present below the stratocumulus, often have a significant impact on the main stratocumulus microphysical properties. This was observed during the ACE-2 (Aerosol Characterisation Experiment-2) campaign designed to study the impact of polluted continental air on stratocumulus formation. In this paper we used a detailed micro-physical chemical parcel model to quantify the extent of this cumulus-stratocumuls coupling. In addition, we made extensive use of microphysical observations from the C-130 aircraft that was operated during ACE-2. For the ACE-2 case studies considered in this paper, our analysis revealed that the chemical, microphysical and optical characteristics of the main stratocumulus cloud deck had significant contributions from cumulus clouds that often penetrated the stratocumulus deck. The amount of fine mode ionic species, the average droplet number concentrations, the effective radii and the optical depths during the flight A562 (when cumulus clouds interacted with the main stratocumulus) were estimated and model runs that included this effect yielded microphysical and optical properties which compared more favourably with the observations than the runs which did not. This study highlights the importance of including these cumulus effects in stratocumulus related modelling studies.

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25

Henry, Pierre-Yves, Jochen Aberle, Christy Ushanth Navaratnam, and Nils Ruther. "Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques." E3S Web of Conferences 40 (2018): 05065. http://dx.doi.org/10.1051/e3sconf/20184005065.

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Physical models are a well-accepted tool in hydraulic engineering, allowing for the detailed characterisation of flow processes and the validation of structure designs with complex boundary conditions. The methods used to construct physical models typically produce a surface roughness which does not necessarily scale with the surface roughness of the prototype. In this context, this paper discusses novel construction methods allowing a detailed reproduction of roughness elements in scaled models, such as Computer Numerically Controlled (CNC) manufacturing techniques and bed casting techniques. In particular, the present paper details the protocols developed to mill out a correct representation of the complex rock-fractured geometry of a closed channel which was obtained from Terrestrial Laser Scanners. The novelty of this scaled model production is the implementation of optical accesses in a closed (pressurized) hydraulic model, to allow for Particle Image Velocimetry measurements with a minimum impact on the reproduced roughness elements. The effectiveness of this production protocol is discussed in the context of modelling the roughness effects on the flow regime.

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Padmaja, S., M. Srinivasulu, and Venkata G. K. M. Pisipati. "Higher Homologues of Mesomorphic Benzylidene Anilines. Manifestation of Smectic Polymorphism." Zeitschrift für Naturforschung A 58, no. 9-10 (October 1, 2003): 573–80. http://dx.doi.org/10.1515/zna-2003-9-1017.

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The synthesis and characterisation of higher homologues of the well-known benzylidene anilines, viz. N-(p-n-tridecyloxy, tetradecyloxy, and hexadecyloxy benzylidene)-p-n-alkylanilines, 13O.m, 14O.m and 16O.m liquid crystalline compounds have exhibited mono, bi and tri phase variant smectic polymorphism. The different liquid crystalline phases are characterized by an optical polarising microscope equipped with a PC based temperature controller. The phase transitions are studied by using differential scanning calorimetry. The results are discussed in the light of the data available on other nO.m compounds.

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Drees, Alissa, and Markus Fischer. "High-Throughput Selection and Characterisation of Aptamers on Optical Next-Generation Sequencers." International Journal of Molecular Sciences 22, no. 17 (August 25, 2021): 9202. http://dx.doi.org/10.3390/ijms22179202.

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Aptamers feature a number of advantages, compared to antibodies. However, their application has been limited so far, mainly because of the complex selection process. ‘High-throughput sequencing fluorescent ligand interaction profiling’ (HiTS–FLIP) significantly increases the selection efficiency and is consequently a very powerful and versatile technology for the selection of high-performance aptamers. It is the first experiment to allow the direct and quantitative measurement of the affinity and specificity of millions of aptamers simultaneously by harnessing the potential of optical next-generation sequencing platforms to perform fluorescence-based binding assays on the clusters displayed on the flow cells and determining their sequence and position in regular high-throughput sequencing. Many variants of the experiment have been developed that allow automation and in situ conversion of DNA clusters into base-modified DNA, RNA, peptides, and even proteins. In addition, the information from mutational assays, performed with HiTS–FLIP, provides deep insights into the relationship between the sequence, structure, and function of aptamers. This enables a detailed understanding of the sequence-specific rules that determine affinity, and thus, supports the evolution of aptamers. Current variants of the HiTS–FLIP experiment and its application in the field of aptamer selection, characterisation, and optimisation are presented in this review.

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D’Emilia, Giulio, and Emanuela Natale. "Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging." Journal of Industrial Engineering 2014 (October 23, 2014): 1–6. http://dx.doi.org/10.1155/2014/623510.

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A methodology is described for the theoretical-experimental evaluation of the measurement uncertainty of the polar and dispersive components of the surface free energy (SFE) in polypropylene films; these parameters are related to the film wettability of adhesives and inks. The proposed method is based on the measurement by means of a vision system of the contact angles of liquid drops deposited on the film itself, which allows for obtaining, through mathematical models drawn from the literature, the physical quantities of interest. The effect of the principal influence parameters has been experimentally evaluated, and testing has allowed the defining of the technical procedures readily transferable in the industry. The uncertainty assessment is interesting not only to correctly evaluate experimental data but also to characterise the reproducibility of the effects of techniques for improving the wettability of films, such as surface treatments.

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29

Quintiliani, Maurizio, Eva M. García-Frutos, Andreas Gouloumis, Purificación Vázquez, Isabelle Ledoux-Rak, Joseph Zyss, Christian G. Claessens, and Tomás Torres. "Synthesis, Characterisation and Nonlinear Optical Properties of Two-Dimensional Octupolar Systems Based on Phthalocyanine Compounds." European Journal of Organic Chemistry 2005, no. 18 (September 2005): 3911–15. http://dx.doi.org/10.1002/ejoc.200500271.

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30

Johnson, N. C., J. A. Harrison, and K. J. Blow. "Demonstration and characterisation of a non-inverting all-optical read/write regenerative memory." Optics Communications 281, no. 17 (September 2008): 4464–69. http://dx.doi.org/10.1016/j.optcom.2008.04.043.

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31

Norambuena-Contreras, Jose, Jose Concha, Luis Arteaga-Pérez, and Irene Gonzalez-Torre. "Synthesis and Characterisation of Alginate-Based Capsules Containing Waste Cooking Oil for Asphalt Self-Healing." Applied Sciences 12, no. 5 (March 7, 2022): 2739. http://dx.doi.org/10.3390/app12052739.

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This paper presents the synthesis and characterisation of biopolymeric capsules for asphalt self-healing. A sodium alginate biopolymer extracted from the cell wall of brown algae was used as the encapsulating material to contain Waste Cooking Oil (WCO) as a potential encapsulated rejuvenating agent for aged bitumen. Polynuclear capsules were synthesised by ionic gelation. The size, surface aspect and internal structure of the WCO capsules were evaluated using Optical and Scanning Electron Microscopy. The physical-chemical properties and thermal stability of the WCO capsules and their components were also evaluated. Moreover, the diffusion process and self-healing capability of the released WCO on cracked bitumen test samples were determined by image analysis through fluorescence microscopy. The main results of this study showed that the WCO capsules presented a suitable morphology to be mixed in asphalt mixtures. WCO capsules and their components presented mechanical and thermal stability and physical-chemical properties which suggest their feasibility for self-healing applications. It was proven that the encapsulated WCO can diffuse in the aged bitumen, reducing its viscosity and promoting the self-healing of microcracks.

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32

Cambré, Sofie, Wim Wenseleers, Jelena Čulin, Sabine Van Doorslaer, Antonio Fonseca, Janos B. Nagy, and Etienne Goovaerts. "Characterisation of Nanohybrids of Porphyrins with Metallic and Semiconducting Carbon Nanotubes by EPR and Optical Spectroscopy." ChemPhysChem 9, no. 13 (September 15, 2008): 1930–41. http://dx.doi.org/10.1002/cphc.200800317.

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Fru, J. N., N. Nombona, and M. Diale. "Synthesis and characterisation of methylammonium lead tri-bromide perovskites thin films by sequential physical vapor deposition." Physica B: Condensed Matter 578 (February 2020): 411884. http://dx.doi.org/10.1016/j.physb.2019.411884.

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Movva, Mounika, and Ravindra Kommineni. "Extraction of cellulose from pistachio shell and physical and mechanical characterisation of cellulose-based nanocomposites." Materials Research Express 4, no. 4 (April 21, 2017): 045014. http://dx.doi.org/10.1088/2053-1591/aa6863.

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Hutchison, Christopher D. M., Susan Parker, Volha Chukhutsina, and Jasper J. van Thor. "Open hardware microsecond dispersive transient absorption spectrometer for linear optical response." Photochemical & Photobiological Sciences 21, no. 1 (November 8, 2021): 23–35. http://dx.doi.org/10.1007/s43630-021-00127-6.

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Abstract An open hardware design and implementation for a transient absorption spectrometer are presented that has microsecond time resolution and measures full difference spectra in the visible spectral region from 380 to 750 nm. The instrument has been designed to allow transient absorption spectroscopy measurements of either low or high quantum yield processes by combining intense sub-microsecond excitation flashes using a xenon lamp together with stroboscopic non-actinic white light probing using LED sources driven under high pulsed current from a capacitor bank. The instrument is sensitive to resolve 0.15 mOD flash-induced differences within 1000 measurements at 20 Hz repetition rate using an inexpensive CCD sensor with 200 μm pixel dimension, 40 K electrons full well capacity and a dynamic range of 1800. The excitation flash has 230 ns pulse duration and the 2 mJ flash energy allows spectral filtering while retaining high power density with focussing to generate mOD signals in the 10–4–10–1 ΔOD range. We present the full electronics design and construction of the flash and probe sources, the optics as well as the timing electronics and CCD spectrometer operation and modification for internal signal referencing. The performance characterisation and example measurements are demonstrated using microsecond TAS of Congo red dye, as an example of a low quantum yield photoreaction at 2% with up to 78% of molecules excited. The instrument is fully open hardware and combines inexpensive selection of commercial components, optics and electronics and allows linear response measurements of photoinduced reactions for the purpose of accurate global analysis of chemical dynamics. Graphical abstract

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Solano, E., E. L. Martín, J. A. Caballero, C. Rodrigo, R. E. Angulo, J. Alcaniz, M. Borges Fernandes, et al. "J-PLUS: Discovery and characterisation of ultracool dwarfs using Virtual Observatory tools." Astronomy & Astrophysics 627 (June 27, 2019): A29. http://dx.doi.org/10.1051/0004-6361/201935256.

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Context. Ultracool dwarfs are objects with spectral types equal to or later than M7. Most of them have been discovered using wide-field imaging surveys. The Virtual Observatory has proven to be very useful for efficiently exploiting these astronomical resources. Aims. We aim to validate a Virtual Observatory methodology designed to discover and characterise ultracool dwarfs in the J-PLUS photometric survey. J-PLUS is a multiband survey carried out with the wide-angle T80Cam optical camera mounted on the 0.83 m telescope JAST/T80 in the Observatorio Astrofísico de Javalambre. We make use of the Internal Data Release covering 528 deg2. Methods. We complemented J-PLUS photometry with other catalogues in the optical and infrared using VOSA, a Virtual Observatory tool that estimates physical parameters from the spectral energy distribution fitting to collections of theoretical models. Objects identified as ultracool dwarfs were distinguished from background M giants and highly reddened stars using parallaxes and proper motions from Gaia DR2. Results. We identify 559 ultracool dwarfs, ranging from i = 16.2 mag to i = 22.4 mag, of which 187 are candidate ultracool dwarfs not previously reported in the literature. This represents an increase in the number of known ultracool dwarfs of about 50% in the region of the sky we studied, particularly at the faint end of our sensitivity, which is interesting as reference for future wide and deep surveys such as Euclid. Three candidates are interesting targets for exoplanet surveys because of their proximity (distances less than 40 pc). We also analysed the kinematics of ultracool dwarfs in our catalogue and found evidence that it is consistent with a Galactic thin-disc population, except for six objects that might be members of the thick disc. Conclusion. The results we obtained validate the proposed methodology, which will be used in future J-PLUS and J-PAS releases. Considering the region of the sky covered by the Internal Data Release used in this work, we estimate that 3000–3500 new ultracool dwarfs will be discovered at the end of the J-PLUS project.

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Betlem, Peter, Thomas Birchall, Kei Ogata, Joonsang Park, Elin Skurtveit, and Kim Senger. "Digital Drill Core Models: Structure-from-Motion as a Tool for the Characterisation, Orientation, and Digital Archiving of Drill Core Samples." Remote Sensing 12, no. 2 (January 19, 2020): 330. http://dx.doi.org/10.3390/rs12020330.

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Structure-from-motion (SfM) photogrammetry enables the cost-effective digital characterisation of seismic- to sub-decimetre-scale geoscientific samples. The technique is commonly used for the characterisation of outcrops, fracture mapping, and increasingly so for the quantification of deformation during geotechnical stress tests. We here apply SfM photogrammetry using off-the-shelf components and software, to generate 25 digital drill core models of drill cores. The selected samples originate from the Longyearbyen CO2 Lab project’s borehole DH4, covering the lowermost cap rock and uppermost reservoir sequences proposed for CO2 sequestration onshore Svalbard. We have come up with a procedure that enables the determination of bulk volumes and densities with precisions and accuracies similar to those of such conventional methods as the immersion in fluid method. We use 3D printed replicas to qualitatively assure the volumes, and show that, with a mean deviation (based on eight samples) of 0.059% compared to proven geotechnical methods, the photogrammetric output is found to be equivalent. We furthermore splice together broken and fragmented core pieces to reconstruct larger core intervals. We unwrap these to generate and characterise 2D orthographic projections of the core edge using analytical workflows developed for the structure-sedimentological characterisation of virtual outcrop models. Drill core orthoprojections can be treated as directly correlatable to optical borehole-wall imagery data, enabling a direct and cost-effective elucidation of in situ drill core orientation and depth, as long as any form of borehole imagery is available. Digital drill core models are thus complementary to existing physical and photographic sample archives, and we foresee that the presented workflow can be adopted for the digitisation and digital storage of other types of geological samples, including degradable and dangerous ice and sediment cores and samples.

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Colombo-Pulgarín, Juan C., Antonio J. Sánchez Egea, Diego J. Celentano, Daniel Martínez Krahmer, Vitaliy Martynenko, and Norberto López de Lacalle. "Mechanical and Chemical Characterisation of TiN and AlTiSiN Coatings on a LPBF Processed IN718 Substrate." Materials 14, no. 16 (August 17, 2021): 4626. http://dx.doi.org/10.3390/ma14164626.

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Wear-resistant coatings development is progressively increasing steeply due to their advantages when applied to mechanical components subjected to abrasive and destructive environments. Titanium nitride (TiN) coating is typically used to enlarge tools and components’ service life and improve their surface quality. On the other hand, AlTiSiN coating intends to be applied to more aggressive environments such as spatial satellites components exposed to solar radiation, extremely high temperatures, and random particles impact. In this work, specimens of Inconel 718 (IN718) were fabricated via laser powder bed fusion (LPBF), and physical vapour deposition (PVD)-deposited with TiN and AlTiSiN as coatings to mechanically and chemically characterise their surface. In this respect, microhardness testing and chemical analysis via glow discharge optical emission spectroscopy (GDOES) were performed. Later, roughness and wear behaviour analyses were carried out to evaluate the mechanical performance of both coatings and their surface and morphological features. The experimental observations allowed the analysis of both studied coatings by comparing them with the substrate processed via LPBF.

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Bellopede, Rossana, Lorena Zichella, and Paola Marini. "Marble Durability Assessment by Means of Total Optical Porosity and Adjacent Grain Analysis." Key Engineering Materials 848 (June 2020): 35–47. http://dx.doi.org/10.4028/www.scientific.net/kem.848.35.

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The presence of pores, cracks and microcracks in marble is one of the main features that govern the processes of decay of this stone material and, although marble is characterised by a modest porosity, there is a clear correlation between the presence and movement of fluids, and the phenomena of alteration. Through the study of porosity, it is possible to better understand the phenomena of alteration and degradation in order to obtain useful information, not only in the field of modern building, but also for the protection and recovery of historical and artistic heritage goods. This study was conducted through the characterisation of parameters directly related with the degree of alteration of the materials: water absorption at atmospheric pressure (EN 13755), open porosity (EN 1936), flexural strength (EN 12372) and bowing (EN 16306 par. 8.2). The physical and mechanical measurements have been compared with the Total Optical Porosity method (TOP) and the Adjacent Grain Analysis (AGA) index (a suggested method to evaluate the marbles’ tendency to bow, in EN 16306 annex C); two different methodologies both based on image analysis. The purpose of this study is to demonstrate the effectiveness, for the assessment of marble durability, of the two techniques of microscopic image analysis, the first correlating to the grain shape and the second to the open porosity index. This was done by comparing the microscopic image analysis results with the physical and mechanical properties, both after artificial ageing and after ten years of natural ageing. The results obtained with the TOP method seem to represent the tendency to decay better than the AGA index. The comparison of image analysis of the thin sections, in different portions of the marble specimens, shows the development of degradation due to atmospheric agents, from the surface to the inside, of naturally aged specimens, confirming recent studies made on different marbles.

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40

Holzer, W., A. Penzkofer, A. Lux, H. H. Hörhold, and E. B. Kley. "Photo-physical and lasing characterisation of neat films of a thianthrene-substituted distyrylbenzene dye (Thianthrene-DSB)." Synthetic Metals 145, no. 2-3 (September 2004): 119–27. http://dx.doi.org/10.1016/j.synthmet.2004.04.027.

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41

Gizdavic-Nikolaidis, Marija R., Júlia Moreira Pupe, Ajay Jose, Luciano Paulino Silva, Dragomir R. Stanisavljev, Darren Svirskis, and Simon Swift. "Eco-friendly enhanced microwave synthesis of polyaniline/chitosan-AgNP composites, their physical characterisation and antibacterial properties." Synthetic Metals 293 (March 2023): 117273. http://dx.doi.org/10.1016/j.synthmet.2022.117273.

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42

Ahmad, Mukhtar, Eijaz Ahmed, Muhammad Ikram, Fezza Zafar, Niaz Ahmed Niaz, Zhanglian Hong, Abdul Hafeez, Khalid Nadeem Riaz, and Waqar Ahmed. "Preparation, Characterisation and Photocatalytic Activity of La-doped ZnO Nanopowders Synthesised using Auto-combustion." Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences 59, no. 1 (February 25, 2016): 1–10. http://dx.doi.org/10.52763/pjsir.phys.sci.59.1.2016.1.10.

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Nanocrystalline nanoparticles of pristine ZnO and La-doped ZnO have been synthesised usinga combustion method using various concentrations of lanthanum dopant followed by calcination for 3 hat 700 °C. The crystalline structure, chemical composition and optical characteristics have been characterisedusing X-ray diffraction (XRD), scanning electron spectroscopy (SEM) attached with energy dispersiveX-ray (EDX) spectroscopy, Brunauer Emmett Teller (BET), UV-vis. spectroscopy and photoluminescence(PL) spectroscopy. Absorption spectra showed that the absorbance increased with La-doping and the blueshift observed was due to an increase in the band gap from 3.24 to 3.27 eV. The photocatalytic activitiesof the samples prepared were evaluated using the photocatalytic degradation of methyl orange (MO) underirradiation by sunlight. The textile mill effluents containing organic matter were also irradiated with sunlightinducing photocatalysis and the chemical oxygen demand (COD) of the treated effluent were investigated.The results showed that the ZnO photocatalyst doped with 1.0 at.% lanthanum exhibited four timesenhancement in the photocatalytic activity compared to pure ZnO.

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43

Zhao, Hong, and Danny O’Hare. "Characterisation and Modeling of Conducting Composite Electrodes." Journal of Physical Chemistry C 112, no. 25 (May 31, 2008): 9351–57. http://dx.doi.org/10.1021/jp711366u.

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44

Ricca, Michela, Giuseppe Paladini, Natalia Rovella, Silvestro Antonio Ruffolo, Luciana Randazzo, Vincenza Crupi, Barbara Fazio, et al. "Archaeometric Characterisation of Decorated Pottery from the Archaeological Site of Villa dei Quintili (Rome, Italy): Preliminary Study." Geosciences 9, no. 4 (April 16, 2019): 172. http://dx.doi.org/10.3390/geosciences9040172.

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This work focused on the study of decorated pottery dated back to the 16th century from the Roman archaeological site of Villa dei Quintili, a monumental complex located in the south-eastern part of Rome (Italy). A minero-petrographic and geochemical study was undertaken to analyse five archaeological samples in order to define textural features and raw materials used for their production, along with the chemical and physical composition of the superficial decorative glazed coatings. For this purpose, different analytical methods were used, such as polarising optical microscope (POM), X-ray diffraction (XRD), micro-Raman spectroscopy, X-Ray fluorescence (XRF), and electron microprobe analysis coupled with energy dispersive spectrometry (EMPA-EDS). The results of such a multidisciplinary approach allowed us to achieve important results crucial to recognise the shards as majolica of the Renaissance period, improving knowledge about manufacturing processes of these renowned painted ceramic artefacts.

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45

Dawson, P., D. Frey, V. Kalathingal, R. Mehfuz, and J. Mitra. "Novel routes to electromagnetic enhancement and its characterisation in surface- and tip-enhanced Raman scattering." Faraday Discussions 205 (2017): 121–48. http://dx.doi.org/10.1039/c7fd00128b.

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Quantitative understanding of the electromagnetic component in enhanced Raman spectroscopy is often difficult to achieve on account of the complex substrate structures utilised. We therefore turn to two structurally simple systems amenable to detailed modelling. The first is tip-enhanced Raman scattering under electron scanning tunnelling microscopy control (STM-TERS) where, appealing to understanding developed in the context of photon emission from STM, it is argued that the localised surface plasmon modes driving the Raman enhancement exist in the visible and near-infrared regime only by virtue of significant modification to the optical properties of the tip and sample metals (gold here). This is due to the strong dc field-induced (∼10⁹V m⁻¹) non-linear corrections to the dielectric function of goldviathe third order susceptibility term in the polarisation. Also, sub-5 nm spatial resolution is shown in the modelling. Secondly, we suggest a novel deployment of hybrid plasmonic waveguide modes in surface enhanced Raman scattering (HPWG-SERS). This delivers strong confinement of electromagnetic energy in a ∼10 nm oxide ‘gap’ between a high-index dielectric material of nanoscale width (a GaAs nanorod and a 100 nm Si slab are considered here) and a metal, yielding a monotonic variation in the Raman enhancement factor as a function of wavelength with no long-wavelength cut-off, both features that contrast with STM-TERS.

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Lesiak, B., L. Stobinski, A. Malolepszy, M. Mazurkiewicz, L. Kövér, and J. Tóth. "Preparation of graphene oxide and characterisation using electron spectroscopy." Journal of Electron Spectroscopy and Related Phenomena 193 (March 2014): 92–99. http://dx.doi.org/10.1016/j.elspec.2014.03.015.

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Barreto, África, Rosa D. García, Carmen Guirado-Fuentes, Emilio Cuevas, A. Fernando Almansa, Celia Milford, Carlos Toledano, Francisco J. Expósito, Juan P. Díaz, and Sergio F. León-Luis. "Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements." Atmospheric Chemistry and Physics 22, no. 17 (August 31, 2022): 11105–24. http://dx.doi.org/10.5194/acp-22-11105-2022.

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Abstract. A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005–2020 from a unique network made up of four stations strategically located from sea level to 3555 m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz de Tenerife – SCO – at sea level and La Laguna – LLO – at 580 m a.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izaña – IZO – at 2373 m a.s.l. and Teide Peak – TPO – at 3555 m a.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol optical depth (AOD), Ångström exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for most of the year, while dust-laden conditions dominate in July and August. The MABL under background conditions appears as a well-mixed layer with a low aerosol concentration (the volume concentration, VolCon, ranges from 0.02 ± 0.01 to 0.04 ± 0.02 µm3 µm−2), a predominance of coarse-mode marine aerosols (the effective radius, Reff, changes from 1.60 ± 0.19 to 1.91 ± 0.34 µm), and a volume contribution of the fine-mode fraction Vf/Vt <0.35. The clean FT is characterised by remarkably low aerosol loading and a predominant impact of fine-mode aerosols throughout the year (Vf/Vt has a maximum value of 0.93 ± 0.13), with an average Reff of 0.16 ± 0.02 µm. However, under dust-laden conditions and mainly in summer, we observe a predominance of coarse-mode aerosols with maximum VolCon values of 0.26 ± 0.23 µm3 µm−2 for the MABL and 0.16 ± 0.12 (0.06 ± 0.05) µm3 µm−2 for IZO (TPO), and a similar and quite consistent fine-mode fraction of 0.12 ± 0.03 in the vertical within the MABL and FT. Similarities in micro-physical and optical intensive aerosol properties confirm that the Saharan Air Layer (SAL) is a well-mixed layer in terms of the particulate composition. An estimation of the difference in the aerosol loading in the 1 km layer between IZO and TPO (in terms of VolCon and AOD) is performed in this study, and this shows that aerosol loading at IZO is double that at TPO, but they have similar fine-mode fractions, effective radii and intensive optical properties. The long-term trend analysis at SCO shows a significant negative trend in the fine-mode AOD between 2005 and 2020 (−1.8 ± 0.5) × 10−5 yr−1, which might be linked to the large reduction in oil-refining SO2 emissions from the SCO refinery in 2012.

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48

Fielding, Lee A., Steven P. Armes, Paul Staniland, Robert Sayer, and Ian Tooley. "Physical adsorption of anisotropic titania nanoparticles onto poly(2-vinylpyridine) latex and characterisation of the resulting nanocomposite particles." Journal of Colloid and Interface Science 426 (July 2014): 170–80. http://dx.doi.org/10.1016/j.jcis.2014.04.002.

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49

Shu, Xuewen, Lin Zhang, and Ian Bennion. "Fabrication and characterisation of ultra-long-period fibre gratings." Optics Communications 203, no. 3-6 (March 2002): 277–81. http://dx.doi.org/10.1016/s0030-4018(02)01185-9.

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50

Brito, J., L. V. Rizzo, P. Herckes, P. C. Vasconcellos, S. E. S. Caumo, A. Fornaro, R. Y. Ynoue, P. Artaxo, and M. F. Andrade. "Physical–chemical characterisation of the particulate matter inside two road tunnels in the São Paulo Metropolitan Area." Atmospheric Chemistry and Physics 13, no. 24 (December 17, 2013): 12199–213. http://dx.doi.org/10.5194/acp-13-12199-2013.

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Abstract. The notable increase in biofuel usage by the road transportation sector in Brazil during recent years has significantly altered the vehicular fuel composition. Consequently, many uncertainties are currently found in particulate matter vehicular emission profiles. In an effort to better characterise the emitted particulate matter, measurements of aerosol physical and chemical properties were undertaken inside two tunnels located in the São Paulo Metropolitan Area (SPMA). The tunnels show very distinct fleet profiles: in the Jânio Quadros (JQ) tunnel, the vast majority of the circulating fleet are light duty vehicles (LDVs), fuelled on average with the same amount of ethanol as gasoline. In the Rodoanel (RA) tunnel, the particulate emission is dominated by heavy duty vehicles (HDVs) fuelled with diesel (5% biodiesel). In the JQ tunnel, PM2.5 concentration was on average 52 μg m−3, with the largest contribution of organic mass (OM, 42%), followed by elemental carbon (EC, 17%) and crustal elements (13%). Sulphate accounted for 7% of PM2.5 and the sum of other trace elements was 10%. In the RA tunnel, PM2.5 was on average 233 μg m−3, mostly composed of EC (52%) and OM (39%). Sulphate, crustal and the trace elements showed a minor contribution with 5%, 1%, and 1%, respectively. The average OC : EC ratio in the JQ tunnel was 1.59 ± 0.09, indicating an important contribution of EC despite the high ethanol fraction in the fuel composition. In the RA tunnel, the OC : EC ratio was 0.49 ± 0.12, consistent with previous measurements of diesel-fuelled HDVs. Besides bulk carbonaceous aerosol measurement, polycyclic aromatic hydrocarbons (PAHs) were quantified. The sum of the PAHs concentration was 56 ± 5 ng m−3 and 45 ± 9 ng m−3 in the RA and JQ tunnel, respectively. In the JQ tunnel, benzo(a)pyrene (BaP) ranged from 0.9 to 6.7 ng m−3 (0.02–0.1‰ of PM2.5) whereas in the RA tunnel BaP ranged from 0.9 to 4.9 ng m−3 (0.004–0. 02‰ of PM2.5), indicating an important relative contribution of LDVs emission to atmospheric BaP. Real-time measurements performed in both tunnels provided aerosol size distributions and optical properties. The average particle count yielded 73 000 cm−3 in the JQ tunnel and 366 000 cm−3 in the RA tunnel, with an average diameter of 48 nm in the former and 39 nm in the latter. Aerosol single scattering albedo, calculated from scattering and absorption observations in the JQ tunnel, indicates a value of 0.5 associated with LDVs. Such single scattering albedo is 20–50% higher than observed in previous tunnel studies, possibly as a result of the large biofuel usage. Given the exceedingly high equivalent black carbon loadings in the RA tunnel, real time light absorption measurements were possible only in the JQ tunnel. Nevertheless, using EC measured from the filters, a single scattering albedo of 0.31 for the RA tunnel has been estimated. The results presented here characterise particulate matter emitted from nearly 1 million vehicles fuelled with a considerable amount of biofuel, providing a unique experimental site worldwide.

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