Barria, P., Ocampo-Melgar, A., Chadwick, C., Galleguillos, M., Garreaud, R., Diaz-Vasconcellos, R., et al. (2022). Comment on: “The impact of a lack of government strategies for sustainable water management and land use planning on the hydrology of water bodies: lessons learned from the disappearance of the Aculeo Lagoon in central Chile” by Valdes-Pineda et al. 2022 in Sustainability, 14(1), 413. Reg. Environ. Change, 22(4), 131.
Abstract: Valdes-Pineda et al. (Sustainability 14:413, 2022) present data for changes in climate, socio-economic, and land use and land cover (LULC) from diverse sources, concluding that the main causes for the desiccation of the Aculeo Lake were the river deviations and aquifer pumping, along with the impact of reduced precipitation. Based on that, they infer that the previous study of Barria et al. (Reg Environ Change 21:1-5, 2021a), which concluded that the impact of the decade-long drought was ten times larger than the increase of human extractions on the lake desiccation lacks scientific validity. We disagree with the conclusions from Valdes-Pineda et al. (Sustainability 14:413, 2022) and document that their article uses fragmentary information of a complex system, misinterprets of our results, and fails to present a reliable attribution methodology. We show that the hypothesis that the disappearance of Aculeo Lake was largely due to local anthropogenic uses is unsupported.
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Cruz, J. J., Escudero, F., Alvarez, E., da Silva, L. F. F., Carvajal, G., Thomsen, M., et al. (2021). Three-wavelength broadband soot pyrometry technique for axisymmetric flames. Opt. Lett., 46(11), 2654–2657.
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.
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Verdugo, I., Cruz, J. J., Alvarez, E., Reszka, P., da Silva, L. F. F., & Fuentes, A. (2020). Candle flame soot sizing by planar time-resolved laser-induced incandescence. Sci Rep, 10(1), 12 pp.
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.
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