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  • Synergy between ground-based remote sensing instruments for retrieving microphysical-optical-radiative properties of atmospheric aerosols
    Publication . Oliveira, Daniel Camilo Fortunato dos Santos; Sicard, Michaël; Rodríguez Gómez, Alejandro Antonio
    The improvements in retrieving microphysical, optical, and radiative properties of aerosols can contribute to more detailed local observations and research, support local or global climate modeling and air quality forecasting, validate satellite products, and contribute to public policies. This PhD thesis aims at achieving such improvements through synergies between ground-based remote-sensing instruments. The objectives are to (1) evaluate the potential of an inversion algorithm, namely GRASP, for retrieving aerosol properties from the synergy between a polarized Sun-sky-lunar photometer and a state-of-the-art ACTRIS/EARLINET multi-wavelength lidar, and (2) estimate long-term aerosol radiative effects by combining net radiative fluxes from pyranometers and Aerosol Optical Depth (AOD) from photometers, and assessing GRASP’s ability to retrieve such effects on a case-by-case basis. To achieve Obj. 1, sensitive tests (noise-free and random noise retrievals) were performed with GRASP for several combinations of ground-based observations, including polarization information as GRASP inputs, for three aerosol scenarios in Barcelona, Spain. The sensitive tests showed that the addition of the Degree of Linear Polarization (DoLP) improved the noise-free and random-noise GRASP inversions, particularly under higher AOD. The gains were most notable for the coarse mode of the optical properties, and for the coarse mode of the Real Refractive Index. To achieve Obj. 2, a direct method was applied to estimate spectral Aerosol Forcing Efficiency (AFE) and Aerosol Radiative Forcing (ARF) for a 14-year database in Barcelona, Spain. The AFE-ARF estimations confirmed a dominant cooling forcing over Barcelona, with the strongest cooling effect caused by mineral dust, followed by urban/industrial-biomass burning and mixed aerosols. Furthermore, the GRASP inversions with DoLP were more accurate for the ARF, agreeing with the direct method in the high-AOD cases.
    2025-09-18Tese de doutoramento Acesso aberto Ver mais
  • Assessing essential oils from Macaronesia: a study on their efficacy against phytopathogenic and obligate biotrophic fungi
    Publication . Ferreira, Rui Miguel; Pereira, Verónica Sousa; Sardinha, Duarte Fernandes; Rodríguez Sabina, Samuel; Cabrera Pérez, Raimundo; Castilho, Paula Machado; Castilho, Paula C
    BACKGROUND: Essential oils (EOs) extracted from eight culinary herbs and spices, some endemic to Macaronesia flora (Cedro nella canariensis, Clinopodium ascendens and Laurus novocanariensis) and others common in Mediterranean cuisine (Cinnamo mum burmannii, Ocimum gratissimum, Origanum vulgare subsp. virens, Syzygium aromaticum and Thymus vulgaris) were evaluated via direct-contact bioassays, both in vitro and in vivo, against three species of phytopathogenic fungi (Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum) and the obligatory biotrophic fungus Oidium farinosum. Carvacrol-rich Origanum vulgare was selected to study the influence of isomerism on bioactivity, because Thymus vulgaris is rich in thymol, a structural isomer of carvacrol. RESULTS:FiveEOsexhibitedstrongtomoderateantifungalactivityandwerefurtherscreenedatlowerconcentrationstoassess their toxicity and growth inhibition thresholds. Cedronella canariensis showed no antifungal activity, whereas Laurus novoca nariensis demonstrated only weak activity against Botrytis cinerea. This fungus was more susceptible to the tested EO than the other phytopathogenic fungi. Origanum vulgare was slightly more effective than Thymus vulgaris, for all three phytopath ogenic fungi. Ocimum gratissimum, Syzygium aromaticum, and Cinnamomum burmannii significantly reduced powdery mildew severity, whereas Origanum vulgare and Thymus vulgaris showed moderate activity. CONCLUSION:Phenylpropanoid-rich EOs, such as Cinnamomum burmannii, Ocimum gratissimum, and S. aromaticum, exhibited the strongest antifungal activity in both bioassays with phytopathogenic and obligate biotrophicfungi.Ourresults confirmthe higher antifungal activity of the phenylpropanoid class of EOs.
    2025-09-18Artigo científico Acesso aberto Ver mais