Measurements of the optical properties of the smoke emissions from plastics, hydrocarbons, and other urban fuels for nuclear winter studies

Patterson, E. M.; Duckworth, R. M.; Wyman, C.M; Powell, E. A.; Gooch, Jan W.

doi:10.1016/0960-1686(91)90171-3

Cited by 26 publications

(6 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The I values were found to vary linearly with the electric signal at the buffer amplifier, so that optical depth was calculated as where V phd and V 0 phd are the measured voltages with and without aerosol, respectively. The total scattering coefficient was measured with cosine sensor [ Patterson et al , 1991; Mulholland and Bryner , 1994]. An ideal response of the sensor is proportional to the cosine angle of the incident laser beam; however, the real sensor deviates slightly from the cosine law with the magnitude of the deviation being less than 1%.…”

Section: Optical Properties Of Aerosolsmentioning

confidence: 99%

Optical properties of soot–water drop agglomerates: An experimental study

et al. 2006

View full text Add to dashboard Cite

[1] Black carbon (BC) and organic carbon (OC) are the largest contributors to the aerosol absorption in the atmosphere, yet the absorption cross sections of BC and OC per unit mass are subject to a large uncertainty due to morphology, physicochemical properties, and the mixing state of carbonaceous particles. Theoretical studies suggest the possibility of an enhanced absorption by soot-cloud drop agglomerates; however, the magnitude of the effect has never been measured directly and remains highly uncertain. This study is a laboratory experiment aimed at the modeling of direct radiation forcing due to soot-water interaction in the presence of glutaric acid, a water-soluble OC. Specifically, we generate, in the laboratory, hydrophobic soot (acetylene soot) and hydrophilic soot (mixture of acetylene soot and glutaric acid) and investigate the structural and optical properties of hydrophobic and hydrophilic soot particles in dry and water-saturated air. Hydrophobic soot (HBS) particles do not exhibit any structural or morphological differences under dry and saturated conditions, whereas hydrophilic soot (HLS) particles, i.e., BC with a monolayer of glutaric acid, collapse into globules when relative humidity (RH) is increased to saturation. The optical properties of HBS show very little dependence on RH while HLS scattering and absorption coefficient increase markedly with RH. For the cases considered here, the maximum enhancement in absorption for a soot-water drop mixture was as much as a factor of 3.5, very similar to theoretical predictions. The data provided in this study should advance the treatment of polluted cloud layers in climate models.

show abstract

Section: Optical Properties Of Aerosolsmentioning

confidence: 99%

Optical properties of soot–water drop agglomerates: An experimental study

et al. 2006

View full text Add to dashboard Cite

show abstract

“…To calculate a correct flame temperature and subsequently a coherent value of f v , both red and blue signals were corrected by self-absorption errors. The specific extinction coefficient for carbonaceous aggregates at 488 nm is about 20% more than at 635 nm, as suggested by some researchers [29][30][31][32] if the carbon density and the flame geometry remain the same. In Fig.…”

Section: Images Post-processing and Analysismentioning

confidence: 77%

Two‐dimensional measurements of primary soot diameter in diffusion flames by two‐dimensional time resolved laser induced incandescence

Potenza

Naccarato

Risi

2014

IET Science, Measurement & Technology

View full text Add to dashboard Cite

Two dimensions primary soot diameter calculation in a laminar diffusion liquid petroleum gas flame by means of laser induced incandescence (LII) is presented in present paper. LII is a high sensitive technique in which a high energy Nd-Yag laser sheet heats soot particles up to a temperature of about 4000 K but without exceeding the sublimation temperature. Radiation from exited soot particles is acquired by means of an intensified coupled charge device (CCD) camera (low gate opening time of 10 ns) synchronised with the laser pulse. By delaying the acquisition time with respect to laser pulse, LII signal decay as function of time has been reconstructed. Performing acquisition at two different wavelengths by means of two interferometric filters (two colour LII) a soot temperature behaviour (related to particles primary diameter) has been calculated. For quantitative measurements of the soot volume fraction a tungsten lamp calibration method for optics was used. Using laser fluence and self-absorption corrections for LII signal, bi-dimensional quantitative measurements can be achieved for soot dimensions and distribution. By means of a flame centre-of-mass alignment on the corrected images for different time steps, it is possible to achieve the soot decay curve for each pixel of the images, performing a two-dimensional (2D) soot primary particles visualisation.

show abstract

“…The presence of such absorption bands would increase total extinction measured in a manner unaccounted for by absorption and scattering predictions for small particles. Optical properties of smoke generated by wood and other household materials have been studied for visible light 6,7 , but again, information on optical properties of these types of materials in the NIR region of interest is unavailable. Optical behavior of smoke is generally well described by the Rayleigh-Debye-Gans (RDG) scattering theory for fractal aggregates, which approximates a particulate medium consisting of aggregates of spherical primary particles of constant diameter, d p , in the Rayleigh size range.…”

Section: Light Extinction By Smoke Aggregatesmentioning

confidence: 99%

Development of FireLidar: an active imaging system for smoke and flame environments

Billmers¹,

Billmers²,

Ludwig³

et al. 2005

SPIE Proceedings

View full text Add to dashboard Cite

FireLidar, an active optical imaging system, is being developed for use as an aid to search and rescue in smoke and flame environments. The system is intended to augment currently available passive thermal imaging technology by imaging in the presence of a thermal bloom, heavy smoke conditions, or species which strongly absorb thermal radiation, such as water. We present experimental verification of a theoretical model for FireLidar. Lidar range equations for compartment fire scenarios are derived and compared to measurements taken in a controlled smoke chamber. Extinction measurements of near-infrared light through soot particulate provide information about optical properties of fire environments necessary to predict Lidar returns. Measured extinction values are compared to a singlescattering approximation, based on the Rayleigh-Debye-Gans scattering theory for fractal aggregates. Component specifications for a FireLidar prototype system are discussed, including laser power, filter bandwidth, and camera integration times. A man-portable prototype system using specified components is scheduled for completion by the end of 2005, with a handheld device following soon thereafter.

show abstract

Measurements of the optical properties of the smoke emissions from plastics, hydrocarbons, and other urban fuels for nuclear winter studies

Cited by 26 publications

References 17 publications

Optical properties of soot–water drop agglomerates: An experimental study

Optical properties of soot–water drop agglomerates: An experimental study

Two‐dimensional measurements of primary soot diameter in diffusion flames by two‐dimensional time resolved laser induced incandescence

Development of FireLidar: an active imaging system for smoke and flame environments

Contact Info

Product

Resources

About