Molecular simulations (energy minimizations and molecular dynamics) of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1) were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2) and COMPASS (H. Sun, J. Phys. Chem., 1998, 102, 7338; ref. 3) force ®elds were tested for their a...

Miniaturized detection systems for nanometer-sized airborne particles are in demand, as in applications for onboard diagnostics downstream particulate filters in modern diesel engines. A soot sensor based on resistivity measurements was developed and characterized. This involved generation of soot particles with properties similar to diesel engines using a quenched co-flow diffusion flame; depo...

A CFD-based numerical model has been developed for the determination of the volume concentration and number density of soot in a laminar diffusion flame of methane in air, under transient condition following ignition of the flame. The transience is studied from the point of ignition till the final steady state is reached. The burner is an axi-symmetric co-flowing one with the fuel issuing throu...

Increased levels of particulate air pollution are associated with increased respiratory and cardiovascular mortality and morbidity. Some epidemiologic and toxicologic research suggests ultrafine particles (UFPs) (< 100 nm) to be more harmful per unit mass than larger particles. Our study was aimed at a quantitative comparison of acute adverse effects of different types of carbonaceous UFPs at a...

In this paper, the dependence of sublimation temperature soot particles synthesized during combustion various hydrocarbons, depending on their size and structure, is obtained. The experimental approach based analysis thermal radiation heated to by a nanosecond laser pulse. was measured using two-color pyrometry method. it proposed use average primary compare data in different flames. It establi...

Laminar, sooting, coflow diffusion flames at atmospheric pressure have been studied experimentally and theoretically as a function of fuel dilution by inert nitrogen. The flames have been investigated with laser diagnostics. Laser extinction has been used to calibrate the experimental soot volume fractions and an improved gating method has been implemented in the laser-induced incandescence (LI...

Soot particles may undergo cloud-processing during atmospheric transport after which the particle porosity and surface wettability can be modified. therefore show varying ice nucleation (IN) abilities via pore condensation freezing (PCF) mechanism, leading to poorly constrained effects on cirrus formation climate. This study simulates a typical condition (at 228 K) for size-selected (200 400 nm...

Atmospheric aerosol particle size distributions at a continental background site in Eastern Germany were examined for a one-year period. Particles were classified using a twin differential mobility particle sizer in a size range between 3 and 800 nm. As a novelty, every second measurement of this experiment involved the removal of volatile chemical compounds in a thermodenuder at 300C. This con...

A wide range aerosol spectrometer (WRAS) was used for comprehensive long term measurements of aerosol size distributions. The system combines the results of an optical aerosol spectrometer with the results of a Scanning Mobility Particle Sizer (SMPS) to record essentially the full size range (5 nm – 32 μm) of atmospheric particles in 72 channels. Measurements were carried out over one year (200...

in this study, a manganite sample with a nominal formula of la0.9sr0.1mno3 was prepared by the microwave assisted sol-gel method and annealing at various temperatures. the structural and magnetic properties of the samples were investigated by xrd, fesem and ac susceptometer, respectively. xrd analysis showed that the samples are a nearly single phase. fesem micrographs showed that by increasing...