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Photosynthesis, chloroplast pigments, and antioxidants in Pinus canariensis under free-air ozone fumigation Texte intégral
2009
Then, Ch | Herbinger, K. | Luis, V.C. | Heerdt, C. | Matyssek, R. | Wieser, G.
High O3 levels, driving uptake and challenging defense, prevail on the Canary Islands, being associated with the hot and dry summers of the Mediterranean-type climate. Pinus canariensis is an endemic conifer species that forms forests across these islands. We investigated the effects of ozone on photosynthesis and biochemical parameters of P. canariensis seedlings exposed to free-air O3 fumigation at Kranzberg Forest, Germany, where ambient O3 levels were similar to those at forest sites in the Canary Islands. The twice-ambient O3 regime (2xO3) neither caused visible injury-like chlorotic or necrotic spots in the needles nor significantly affected violaxanthin, antheraxanthin and zeaxanthin levels and the de-epoxidation state of the xanthophyll cycle. In parallel, stomatal conductance for water vapour, net photosynthesis, intercellular CO2 concentration, chlorophyll fluorescence parameters, as well as antioxidant levels were hardly affected. It is concluded that presently prevailing O3 levels do not impose severe stress on P. canariensis seedlings.
Afficher plus [+] Moins [-]Tailoring activated carbons from Pinus canariensis cones for post-combustion CO2 capture Texte intégral
2020
Gomez-Delgado, Edward | Nunell, Gisel | Cukierman, Ana Lea | Bonelli, Pablo
Tailoring activated carbons from Pinus canariensis cones for post-combustion CO2 capture Texte intégral
2020
Gomez-Delgado, Edward | Nunell, Gisel | Cukierman, Ana Lea | Bonelli, Pablo
Activated carbons (ACs) from Pinus canariensis cones were developed by KOH chemical activation. The effect of the impregnation KOH/carbonized cones ratio (IR = 1, 2, or 3) and temperature (873, 973, 1073 K) on main chemical, textural, and morphological characteristics of the resulting ACs was systematically examined. CO₂ adsorption capacity from gaseous streams was evaluated by gravimetric adsorption tests, and the analysis of breakthrough curves was determined in a packed-bed column at 303 K and atmospheric pressure. Comparison of CO₂ adsorption capacities of the ACs at 273 K and 303 K at equilibrium showed that those samples developed at 973 K with IR = 3 (BET surface area ~ 1900 m² g⁻¹) attained the highest values (6.4 mmol g⁻¹ and 1.9 mmol g⁻¹, respectively), even though the ACs obtained at 1073 K with the same IR exhibited the largest surface area (2200 m² g⁻¹). Thermodynamic parameters evaluated from CO₂ adsorption isotherms determined in the range 273–333 K for the former sample pointed to a physisorption, spontaneous, and exothermic process; isosteric heat of adsorption was also estimated for the range of surface coverage of the equilibrium isotherms. The kinetics of CO₂ adsorption onto all the ACs was successfully described by the linear driving force model. The breakthrough curves were properly represented by the Thomas’ model, the longest breakthrough time and highest adsorption capacity being also attained for the bed packed with the ACs developed at 973 K with IR = 3. Higher CO₂ adsorption capacities of the ACs were directly related to the presence of narrow micropores (< 0.9 nm) induced by the stronger activation conditions. However, an excessively severe combination of the IR and activation temperature exerted a negative influence on CO₂ adsorption onto the ACs, likely due to micropores widening.
Afficher plus [+] Moins [-]Tailoring activated carbons from Pinus canariensis cones for post-combustion CO2 capture Texte intégral
2020
Gomez Delgado, Edward Enrique | Nunell, Gisel Vanesa | Cukierman, Ana Lea | Bonelli, Pablo Ricardo
Activated carbons (ACs) from Pinus canariensis cones were developed by KOH chemical activation. The effect of the impregnation KOH/carbonized cones ratio (IR = 1, 2, or 3) and temperature (873, 973, 1073 K) on main chemical, textural, and morphological characteristics of the resulting ACs was systematically examined. CO2 adsorption capacity from gaseous streams was evaluated by gravimetric adsorption tests, and the analysis of breakthrough curves was determined in a packed-bed column at 303 K and atmospheric pressure. Comparison of CO2 adsorption capacities of the ACs at 273 K and 303 K at equilibrium showed that those samples developed at 973 K with IR = 3 (BET surface area ~ 1900 m2 g−1) attained the highest values (6.4 mmol g−1 and 1.9 mmol g−1, respectively), even though the ACs obtained at 1073 K with the same IR exhibited the largest surface area (2200 m2 g−1). Thermodynamic parameters evaluated from CO2 adsorption isotherms determined in the range 273–333 K for the former sample pointed to a physisorption, spontaneous, and exothermic process; isosteric heat of adsorption was also estimated for the range of surface coverage of the equilibrium isotherms. The kinetics of CO2 adsorption onto all the ACs was successfully described by the linear driving force model. The breakthrough curves were properly represented by the Thomas’ model, the longest breakthrough time and highest adsorption capacity being also attained for the bed packed with the ACs developed at 973 K with IR = 3. Higher CO2 adsorption capacities of the ACs were directly related to the presence of narrow micropores (< 0.9 nm) induced by the stronger activation conditions. However, an excessively severe combination of the IR and activation temperature exerted a negative influence on CO2 adsorption onto the ACs, likely due to micropores widening. | Fil: Gomez Delgado, Edward Enrique. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina | Fil: Nunell, Gisel Vanesa. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina | Fil: Cukierman, Ana Lea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina | Fil: Bonelli, Pablo Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina
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