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Author Cruz, J.J.; Escudero, F.; Alvarez, E.; da Silva, L.F.F.; Carvajal, G.; Thomsen, M.; Fuentes, A. doi  openurl
  Title Three-wavelength broadband soot pyrometry technique for axisymmetric flames Type
  Year 2021 Publication Optics Letters Abbreviated Journal Opt. Lett.  
  Volume 46 Issue 11 Pages 2654-2657  
  Keywords VOLUME FRACTION; DIFFUSION FLAMES; TEMPERATURE; ABSORPTION; ETHYLENE  
  Abstract Soot temperature measurements in laminar flames are often performed through two-color broadband emission pyrometry (BEMI) or modulated absorption/emission (BMAE) techniques, using models to relate the ratio between flame intensities at two different wavelengths with soot temperature. To benefit from wider spectral range and increase the accuracy of experimental estimation of soot temperature, this work proposes a new approach that uses three-color broadband images captured with a basic color camera. The methodology is first validated through simulations using numerically generated flames from the CoFlame code and then used to retrieve soot temperature in an experimental campaign. The experimental results show that using three-color and BEMI provides smoother reconstruction of soot temperature than two-color and BMAE when small disturbances exist in the measured signals due to a reduced experimental noise effect. A sensitivity analysis shows that the retrieved temperature from three-color BEMI is more resilient to variations on the ratio of measured signals than BMAE, which is confirmed by an error propagation analysis based on a Monte Carlo approach.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0146-9592 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000658132700025 Approved  
  Call Number UAI @ alexi.delcanto @ Serial 1413  
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Author Reszka, P.; Cruz, J.J.; Valdivia, J.; Gonzalez, F.; Rivera, J.; Carvajal, C.; Fuentes, A. doi  openurl
  Title Ignition delay times of live and dead pinus radiata needles Type
  Year 2020 Publication Fire Safety Journal Abbreviated Journal Fire Saf. J.  
  Volume 112 Issue Pages 7 pp  
  Keywords Leaf senescence; Photosynthetic pigments; Critical heat flux; Moisture content; Wildland fire  
  Abstract There are still many open questions related to the fire behavior of live and dead wildland fuels and their senescence process. We have physically and biochemically studied live and dead pinus radiata needles, their aging process, and their fire behavior using a systematic aging procedure which allows to characterize the evolution of the fuel moisture content and the photosynthetic pigments over time, and to determine the period of time after sample collection in which specimens can be considered to be alive. Results show that pine needles stay alive for up to 12 h after collection if they remain attached to the twigs. The influence of senescence on spontaneous ignition was tested on two bench-scale devices, the I-FIT and the SCALA, under discontinuous and continuous configurations, respectively. Live pine needles showed larger critical heat fluxes than dead needles, while dead and re-hydrated samples have increased critical heat fluxes for greater moisture contents. Experimental results were interpreted with thermal models based on a two-phase description of the fuel layer. We established a correlation of the form 1/t(ig)proportional to q(inc)" for both ignition configurations, which is adequate for engineering applications and allows the estimation of effective properties for wildland fuel beds.  
  Address [Reszka, P.; Valdivia, J.] Univ Adolfo Ibanez, Fac Engn & Sci, Santiago, Chile, Email: andres.fuentes@usm.cl  
  Corporate Author Thesis  
  Publisher Elsevier Sci Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0379-7112 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000527282900005 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 1146  
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Author Verdugo, I.; Cruz, J.J.; Alvarez, E.; Reszka, P.; da Silva, L.F.F.; Fuentes, A. doi  openurl
  Title Candle flame soot sizing by planar time-resolved laser-induced incandescence Type
  Year 2020 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 10 Issue 1 Pages 12 pp  
  Keywords  
  Abstract Soot emissions from flaming combustion are relevant as a significant source of atmospheric pollution and as a source of nanomaterials. Candles are interesting targets for soot characterization studies since they burn complex fuels with a large number of carbon atoms, and yield stable and repeatable flames. We characterized the soot particle size distributions in a candle flame using the planar two-color time-resolved laser induced incandescence (2D-2C TiRe-LII) technique, which has been successfully applied to different combustion applications, but never before on a candle flame. Soot particles are heated with a planar laser sheet to temperatures above the normal flame temperatures. The incandescent soot particles emit thermal radiation, which decays over time when the particles cool down to the flame temperature. By analyzing the temporal decay of the incandescence signal, soot particle size distributions within the flame are obtained. Our results are consistent with previous works, and show that the outer edges of the flame are characterized by larger particles (approximate to 60 nm), whereas smaller particles (approximate to 25 nm) are found in the central regions. We also show that our effective temperature estimates have a maximum error of 100 K at early times, which decreases as the particles cool.  
  Address [Verdugo, Ignacio; Jose Cruz, Juan; Alvarez, Emilio; Fuentes, Andres] Univ Tecn Federico Santa Maria, Dept Ind, Av Espana 1680,Casilla 110-V, Valparaiso, Chile, Email: andres.fuentes@usm.cl  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000548564900078 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 1178  
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