An experimental study of the interaction of a planar diffusion flame with a line vortex is presented. A planar diffusion flame is established between two coflowing, equal velocity streams of acetylene diluted with nitrogen and air. A line vortex is generated on demand by momentarily pulsing one of the flow streams by way of electromagnetic actuation of a piston in the flow apparatus. The flame–...

Soot black carbon (here expressed as GBC) is present in sediments of Central Park and Prospect Park Lakes, New York City (NYC), and peaks in the middle of the 20th Century at the highest values (1-3% dry weight) ever reported in urban lakes. During that period (approximately 1940-1970), the GBC represents up to 28% of the total organic carbon (OC). Radionuclide-normalized whole core inventories...

We present an experimental comparison of photoacoustic responsivities common highly absorbing carbon-based materials. The was carried out with parameters relevant for power detectors and Fourier-transform infrared (FTIR) spectroscopy: we covered a broad wavelength range from the visible red to far (633 nm 25 ?m) regime low acoustic frequencies (< 1 kHz). investigated materials include candle so...

The flame and soot structure, including soot primary particle nucleation, surface growth and oxidation properties, of 6 premixed and 20 diffusion flames were studied experimentally for various fuels, at temperatures of 1400-2350 K and at pressures of 13-811 kPa (0.1-8.0 atm). Measurements were made along the axes of flames with the reactants at normal temperature (300 K). The following properti...

The dynamics of soot formation in turbulent ethylene–air nonpremixed counterflow flames is studied using direct numerical simulation (DNS) with a semi-empirical soot model and the discrete ordinate method (DOM) as a radiation solver. Transient characteristics of soot behavior are studies by a model problem of flame interaction with turbulence inflow at various intensities. The interaction betwe...

Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of lightabsorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru. Durin...

Effective temperatures of pulsed-laser-heated soot particles were derived from their thermal emission intensities using optical pyrometry in a laminar ethylene coflow diffusion flame. The present study concerns conditions of relatively low laser fluences under which soot particles are heated to temperatures below 3500 K to avoid complications of soot particle vaporization in both the experiment...

The high-energy-density (HED) fuels developed under U.S. Navy sponsorship as a replacement for conventional liquid fuels in its missile propulsion systems have the drawback of high soot propensity: this makes missiles visible and thus strategically unacceptable. Experimental evidence of heavy sooting from such potential fuels has been presented by Law[l]. Soot propensity is defined here as the ...

To calculate soot source terms a new detailed kinetic soot model is applied to study the formation and oxidation of soot particles in turbulent flames. The model is based on a detailed description of the chemical and physical processes leading to the formation of soot. It can be subdivided into the growth of polycyclic aromatic hydrocarbons (PAHs) in the gas phase reactions and the processes of...

Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with so...