We use the superposition T-matrix method to compute the scattering matrix elements and optical cross-sections for a variety of complex soot and soot-containing aggregate particles in random orientation at a visible wavelength 0.628 mm. It is shown that random variations in the geometrical configuration of monomers in a soot cluster for fixed fractal dimension and prefactor, monomer size, and nu...

In this study, the microstructure and oxidation behaviour of soot from the raw exhaust of a Euro IV test heavy duty (HD) diesel engine is investigated and compared to that of spark discharge soot and hexabenzocoronene (HBC, C42H18). We find a microstructure-controlled reactivity toward oxidation of all three samples in 5% O2 in N2. The spark discharge soot with its fine primary particles and fu...

Tests of ultra-low sulfur diesel blended with soy-biodiesel at 5% and 20% were conducted using a 2002 model year Cummins ISB engine (with exhaust gas recirculation) that had been retrofitted with a passively regenerated catalyzed diesel particulate filter (DPF). Results show that on average, the DPF balance point temperature (BPT) is 45°C and 112°C lower for B20 blends and neat biodiesel, respe...

OBJECTIVES To explore chimney sweeping work tasks, chimney sweeps' use of protective equipment, and type of fuel used by clients, over time. Further, to assess work-relatedness of current eye and airway symptoms. METHODS In a cross-sectional study in 2011, male Swedish chimney sweeps (n = 483; age 21-69 years) answered a questionnaire about their occupational history and eye and airway sympto...

Most liquid fuels contain compounds with one or more unsaturated CC bonds. Previous studies have observed that the fuel reactivity and ignition behavior are strongly influenced by the presence and number of double bonds in the fuel molecular structure. Here, we report a numerical investigation on the effect of fuel unsaturation on PAHs and soot emissions in partially premixed flames (PPFs) bur...

Firings at cloth targets and at human skin from autopsy material were performed from the pistols 7.62 mm Tokarev (TT), 9 mm Makarov (PM) and 9 x 19 mm Glock 19 with common ammunition. The differences were in the soot deposit pattern, the degree of scorching of the synthetic fibres on the edges of the entrance hole and in the findings of the soot and the gunpowder particles. The results were sim...

Particulate matter and NO x emissions from diesel exhaust remains one of the most pressing environmental problems. We explore the use of hierarchically ordered mixed Fe-Ce-Zr oxides for the simultaneous capture and oxidation of soot and reduction of NO x by ammonia in a single step. The optimized material can effectively trap the model soot particles in its open macroporous structure and oxidiz...

Knowledge of the chemical structure of young soot and its precursors is very useful in the understanding of the paths leading to soot particle inception. This paper presents analyses of the chemical functional groups, based on FT-IR and 1H NMR spectroscopy of the products obtained in an ethylene inverse diffusion flame. The trends in the data indicate that the soluble fraction of the soot becom...

The laminar smoke point properties of jet diffusion f lames-the luminous flame length, the residence time, and the fuel flow rate, at the onset of soot emission from the flames--have proven to be useful global measures of the soot properties of nonpremixed flames. These measures provide a means to rate several aspects of sooting properties: the relative tendency of various fuels to emit soot fr...

A new low-cost optical diagnostic technique, called Cone Beam Tomographic Three Colour Spectrometry (CBT-TCS), has been developed to measure the planar distributions of temperature, soot particle size, and soot volume fraction in a co-flow axi-symmetric laminar diffusion flame. The image of a flame is recorded by a colour camera, and then by using colour interpolation and applying a cone beam t...