https://ria.asturias.es/RIA/handle/123456789/364 2025-12-20T12:09:13Z 2025-12-20T12:09:13Z Querejeta Montes, Nausika González Plaza, Marta Rubiera González, Fernando Pevida García, Covadonga https://ria.asturias.es/RIA/handle/123456789/6745 2018-04-19T11:44:42Z 2016-05-12T00:00:00Z

Title: Water Vapor Adsorption on Biomass Based Carbons under Post-Combustion CO2 Capture Conditions: Effect of Post-Treatment Authors: Querejeta Montes, Nausika; González Plaza, Marta; Rubiera González, Fernando; Pevida García, Covadonga Abstract: The effect of post-treatment upon the H2O adsorption performance of biomass-based carbons was studied under post-combustion CO2 capture conditions. Oxygen surface functionalities were partially replaced through heat treatment, acid washing, and wet impregnation with amines. The surface chemistry of the final carbon is strongly affected by the type of post-treatment: acid treatment introduces a greater amount of oxygen whereas it is substantially reduced after thermal treatment. The porous texture of the carbons is also influenced by post-treatment: the wider pore volume is somewhat reduced, while narrow microporosity remains unaltered only after acid treatment. Despite heat treatment leading to a reduction in the number of oxygen surface groups, water vapor adsorption was enhanced in the higher pressure range. On the other hand acid treatment and wet impregnation with amines reduce the total water vapor uptake thus being more suitable for post-combustion CO2 capture applications.

2016-05-12T00:00:00Z Fernández-Pascual, Eduardo Jiménez-Alfaro, Borja Díaz, Tomás Emilio https://ria.asturias.es/RIA/handle/123456789/12008 2019-09-04T06:44:21Z 2013-01-12T00:00:00Z

Title: The temperature dimension of the seed germination niche in fen wetlands Authors: Fernández-Pascual, Eduardo; Jiménez-Alfaro, Borja; Díaz, Tomás Emilio Abstract: The seed germination niche partly determines adaptation, ecological breadth and geographic range in plant species. In temperate wetlands environmental temperature is the chief regulator of germination timing, but the ecological significance of high and low temperatures during dormancy break and germination is still poorly understood. Our aim was to characterize the temperature dimension of the germination niche in mountain base-rich fens, determining (1) the effect of different temperatures on dormancy break and germination, and (2) whether different germination strategies may be identified at the species level. We conducted laboratory germination experiments with seeds of 15 species from these habitats, collected in 18 fen sites in the Cantabrian Mountains (Spain) for two consecutive years. In all the species the seeds were totally or conditionally dormant at dispersal and stratification produced a significant increase of germination. In most cases there was not an obligatory requirement for cold temperatures during dormancy break, since warm stratification promoted germination as well. Although the optimal germination thermoperiod was generally high (30/20ºC), most species could also germinate at lower temperatures after cold-stratification. We also identified a group of species associated to cold-water springs that germinated only at low temperatures. Our results demonstrate that dormancy break in mountain base-rich fens does not obligatorily depend on cold temperatures during overwintering. Furthermore, germination at cool temperatures may be more widespread in wetland habitats than previously thought. The existence of two distinctive germination strategies, ‘warm’ and ‘cool’, can potentially give rise to divergent species responses to climate change.

2013-01-12T00:00:00Z Moris, Jose V. Ascoli, Davide Hunt, Hugh G.P. https://ria.asturias.es/RIA/handle/123456789/14728 2024-03-15T07:21:51Z 2024-03-14T00:00:00Z

Title: Survival functions of holdover time of lightning-ignited wildfires Authors: Moris, Jose V.; Ascoli, Davide; Hunt, Hugh G.P. Abstract: Lightning-ignited wildfires (LIWs) can go unreported for hours, days or even weeks before being reported. This is due to the fact that some LIWs present an intermediate phase between ignition and detection characterized by a smoldering combustion. Holdover time is generally defined as the time between lightning-induced ignition and fire detection. This study aims at obtaining survival functions to estimate the probability of a LIW reaching a certain holdover time. To this end, we fitted nine different probability distributions (exponential, chi-squared, log-normal, log-logistic, F, gamma, Weibull, Pareto, and Gompertz) to data from a database gathering 42 frequency distributions of holdover time obtained from more than 152,375 LIWs in 13 countries from 1921 to 2020. Gamma distributions provide the best fits to the observed holdover times. Accordingly, we estimated several survival functions derived from gamma distributions fitted to holdover time data. The survival functions are monotonically decreasing functions characterized by high probabilities for short holdover times and low probabilities for long holdover times. These survival functions can be used for holdover times of LIWs occurring globally as well as in boreal, Mediterranean and temperate coniferous forest biomes. Survival functions are intended to provide a more reliable way to assess holdover time-based probabilities of lightning causing wildfires.

2024-03-14T00:00:00Z Esteban-Díez, Gonzalo Gil, María Victoria Pevida, Covadonga Chen, De Rubiera, Fernando https://ria.asturias.es/RIA/handle/123456789/8028 2018-04-19T11:44:04Z 2016-09-14T00:00:00Z

Title: Sorption enhanced catalytic steam reforming of blends of bio-oil model compounds for hydrogen production Authors: Esteban-Díez, Gonzalo; Gil, María Victoria; Pevida, Covadonga; Chen, De; Rubiera, Fernando Abstract: The objective of the present study was to investigate the effect of reaction temperature on H2 production by sorption enhanced steam reforming of bio-oil over a Pd/Ni-Co hydrotalcite-derived catalyst and using dolomite as CO2 sorbent. Experiments were carried out in a fluidized bed reactor at temperatures between 525 and 725 °C. In order to simulate bio-oil behavior, acetic acid, acetone, phenol and blends of the three model compounds were tested. Analysis of the thermodynamic equilibrium of the process was conducted by means of Aspen Plus software in order to assess the theoretical feasibility of the process.

2016-09-14T00:00:00Z