Zeolites for CO2–CO–O2 Separation to Obtain CO2-Neutral Fuels

Carbon dioxide release has become an important global issue due to the significant and continuous rise in atmospheric CO2 concentrations and the depletion of carbon-based energy resources. Plasmolysis is a very energy-efficient process for reintroducing CO2 into energy and chemical cycles by converting CO2 into CO and O2 utilizing renewable electricity. The bottleneck of the process is that CO remains mixed with O2 and residual CO2. Therefore, efficient gas separation and recuperation are essential for obtaining pure CO, which, via water gas shift and Fischer–Tropsch reactions, can lead to the production of CO2-neutral fuels. The idea behind this work is to provide a separation mechanism based on zeolites to optimize the separation of carbon dioxide, carbon monoxide, and oxygen under mild operational conditions. To achieve this goal, we performed a thorough screening of available zeolites based on topology and adsorptive properties using molecular simulation and ideal adsorption solution theory. FAU, BRE, and MTW are identified as suitable topologies for these separation processes. FAU can be used for the separation of carbon dioxide from carbon monoxide and oxygen and BRE or MTW for the separation of carbon monoxide from oxygen. These results are reinforced by pressure swing adsorption simulations at room temperature combining adsorption columns with pure silica FAU zeolite and zeolite BRE at a Si/Al ratio of 3. These zeolites have the added advantage of being commercially available.</p

Modelling ozone stomatal flux over wheat under Mediterranean conditions

Correct estimation of leaf-level stomatal conductance (gsto) is central for current ozone (O3) risk assessment of wheat yield loss based on the absorbed O3 phytotoxic dose (POD). The gsto model parameterizations developed in Europe must be checked in the different climatic regions where they are going to be applied in order to reduce the uncertainties associated with the POD approach. This work proposes a new gsto model parameterization for estimating POD of Triticum aestivum and Triticum durum under Mediterranean conditions, based on phenological observations over 25 years and gsto field measurements during 5 growing seasons. Results show that POD in the Mediterranean area might be higher than previously estimated. However, caution must be paid when assessing the risk of yield loss for wheat in this area since field validation of O3 impacts is still limited

A Functional Role of RB-Dependent Pathway in the Control of Quiescence in Adult Epidermal Stem Cells Revealed by Genomic Profiling

Continuous cell renewal in mouse epidermis is at the expense of a pool of pluripotent cells that lie in a well defined niche in the hair follicle known as the bulge. To identify mechanisms controlling hair follicle stem cell homeostasis, we developed a strategy to isolate adult bulge stem cells in mice and to define their transcriptional profile. We observed that a large number of transcripts are underexpressed in hair follicle stem cells when compared to non-stem cells. Importantly, the majority of these downregulated genes are involved in cell cycle. Using bioinformatics tools, we identified the E2F transcription factor family as a potential element involved in the regulation of these transcripts. To determine their functional role, we used engineered mice lacking Rb gene in epidermis, which showed increased expression of most E2F family members and increased E2F transcriptional activity. Experiments designed to analyze epidermal stem cell functionality (i.e.: hair regrowth and wound healing) imply a role of the Rb-E2F axis in the control of stem cell quiescence in epidermis

Potential of CO2 capture from flue gases by physicochemical and biological methods: A comparative study

We compare the industrial viability of two emerging technologies for CO2 capture from flue gases, i.e., adsorption in porous commercial zeolites and biomass production by microalgae. Our study is organized in two steps: first, the best system is selected (either zeolite type or microalgae strain). Second, their performance is quantified and their advantages at real conditions discussed. For the physicochemical process, we find that commercial zeolite MFI is the best choice for CO2 capture from a typical industrial flue gas emission. Numerical dual PSA cycle simulations at ambient conditions yield 8 kg m−3 bed h−1 and an energy consumption of 0.987 MJ per kg of captured CO2. As regards the biological process, evaluation of several microalgae strains in continuous mode using low-cost resources (waste water, fertilizers, flue gases), results in Scenedesmus almeriensis as the most promising strain. The maximal capacity of CO2 capture at laboratory conditions was 0.1 kg m−3h−1, allowing to produce up to 0.06 of kg m−3h−1 of biomass (3% maximal photosynthetic efficiency). Although this is a significantly lower value, the produced biomass, being composed by carbohydrates, entails an overall economic yield of 0.6 € m−3·day. To demonstrate reliability at large scale, experiments were performed in a 100 m2 pilot raceway reactor under outdoor conditions. We measured 54 g of CO2/m2·day (=197 tn/ha·year) and a biomass productivity of 21 g/m2·day (=75 tn/ha·year). The energy consumption approaches to 0.48 MJ/kgCO2, lower than zeolites adsorption. Still, zeolites can be advantageous as they offer higher productivity, lower energy consumption than amines-based methods, and possibility of producing added-value chemical products, such as methanol, CO or CH4

Potential of CO2 capture from flue gases by physicochemical and biological methods: a comparative study

The industrial viability of two emerging technologies for CO2 capture from flue gases, i.e., adsorption in porous commercial zeolites and biomass production by microalgae, is compared. Our study is organized in two steps: first, the best system is selected (either zeolite type or microalgae strain). Second, their performance is quantified and their advantages at real conditions discussed. For the physicochemical process, we find that commercial zeolite MFI is the best choice for CO2 capture from a typical industrial flue gas emission. Numerical dual PSA cycle simulations at ambient conditions yield 8 kg m-3 bed h-1 and an energy consumption of 0.987 MJ per kg of captured CO2. As regards the biological process, evaluation of several microalgae strains in continuous mode using low cost resources (waste water, fertilizers, flue gases), results in Scenedesmus almeriensis as the most promising strain. The maximal capacity of CO2 capture at laboratory conditions was 0.1 kg m-3 h -1 , allowing to produce up to 0.06 of kg m-3 h -1 of biomass (3% maximal photosynthetic efficiency). Although this is a significantly lower value, the produced biomass, being composed by carbohydrates, entails an overall economic yield of 0.6 € m- 3 ·day. To demonstrate reliability at large scale, experiments were performed in a 100 m2 pilot raceway reactor under outdoor conditions. We measured 54 g of CO2/m2 ·day (= 197 tn/ha·year) and a biomass productivity of 21 g/m2·day (= 75 tn/ha·year). The energy consumption approaches to 0.48 MJ/kgCO2, lower than zeolites adsorption. Still, zeolites can be advantageous as they offer higher productivity, lower energy consumption than amines-based methods, and possibility of producing added-value chemical products, such as methanol, CO or CH4

Potential of CO2 capture from flue gases by physicochemical and biological methods: A comparative study

We compare the industrial viability of two emerging technologies for CO2 capture from flue gases, i.e., adsorption in porous commercial zeolites and biomass production by microalgae. Our study is organized in two steps: first, the best system is selected (either zeolite type or microalgae strain). Second, their performance is quantified and their advantages at real conditions discussed. For the physicochemical process, we find that commercial zeolite MFI is the best choice for CO2 capture from a typical industrial flue gas emission. Numerical dual PSA cycle simulations at ambient conditions yield 8 kg m−3 bed h−1 and an energy consumption of 0.987 MJ per kg of captured CO2. As regards the biological process, evaluation of several microalgae strains in continuous mode using low-cost resources (waste water, fertilizers, flue gases), results in Scenedesmus almeriensis as the most promising strain. The maximal capacity of CO2 capture at laboratory conditions was 0.1 kg m−3h−1, allowing to produce up to 0.06 of kg m−3h−1 of biomass (3% maximal photosynthetic efficiency). Although this is a significantly lower value, the produced biomass, being composed by carbohydrates, entails an overall economic yield of 0.6 € m−3·day. To demonstrate reliability at large scale, experiments were performed in a 100 m2 pilot raceway reactor under outdoor conditions. We measured 54 g of CO2/m2·day (=197 tn/ha·year) and a biomass productivity of 21 g/m2·day (=75 tn/ha·year). The energy consumption approaches to 0.48 MJ/kgCO2, lower than zeolites adsorption. Still, zeolites can be advantageous as they offer higher productivity, lower energy consumption than amines-based methods, and possibility of producing added-value chemical products, such as methanol, CO or CH4.This study was carried out with the financial support of Junta de Andalucía, grant FQM 1851 and the company, SETEC. We are grateful for the practical assistance kindly given by the staff of the Las Palmerillas Experimental Station, part of the Cajamar Foundation. Financial support from the Ministry of Economy and Competitiveness of Spain through project CTM2017-84033-R is gratefully acknowledged.Peer reviewe

L'art préhistorique, une archéologie

Depuis la découverte de la grotte Chauvet, en 1994, les études en art préhistorique ont bénéficié d’un renouvellement profond des connaissances, des outils, mais aussi des approches méthodologiques. Après les découvertes vient la reconnaissance de l’ancienneté de cet art. L’art pariétal s’étudie, à partir des années 1970-1980, dans son contexte archéologique. Les datations, les fouilles éloignent la grotte de l’image de sanctuaire à laquelle elle restait alors le plus souvent associée. Des fonctions sociales plus complexes émergent et nourrissent aussi de nouvelles problématiques. Des territoires graphiques inédits apparaissent et modifient sensiblement la cartographie « pariétale » de l’Europe. Au Brésil, en Australie, les découvertes participent à l’internationalisation des recherches, débouchant sur une dynamique commune, comme le souci d’appréhender les sites dans leur globalité, à la croisée de questionnements autant archéologiques qu’environnementaux, mais aussi conservatoires, qui génèrent de nouvelles approches. La multidisciplinarité fait donc son entrée sur ce terrain. Si l’émerveillement et la fascination restent les mêmes en découvrant Armintxe en 2016 que 150 ans auparavant sous le plafond d’Altamira, les approches scientifiques ont en revanche considérablement évolué pour ancrer fermement l’étude des productions graphiques dans l’archéologie préhistorique

Empathy and prosocial behaviour during adolescente

Aunque la relación entre empatía y prosocialidad viene siendo estudiada desde hace años prevalece aún una importante indefinición conceptual e incluso de resultados. Este trabajo pretende aportar algo de luz a la relación entre ambos conceptos y otras variables del contexto social en una muestra de adolescentes. Un total de 513 adolescentes, 221 chicos y 292 chicas de edades comprendidas entre los 13 y los 19 años cumplimentaron un cuestionario que incluía medidas sobre empatía, conducta prosocial, y aspectos relacionados con las variables familiares y de relación con los iguales. Entre los resultados obtenidos podemos destacar la relación existente entre conducta prosocial y empatía disposicional, y entre estas dos variables y las relaciones con la familia y con el grupo de los iguales. Así mismo, y en concordancia con abundante literatura científica, hallamos mayores niveles de prosocialidad y empatía en las chicas que en los chicos.The relationship between empathy and prosocial behaviour has been an area of research for many years. Nevertheless, to this day, there is a lack of clarity not only in the definition of the concepts but also in the various results on the subject. The aim of this study is to shed some light in examining the relationship of both concepts with other variables of social context. To achieve this goal a sample of 513 adolescents, 221 boys and 292 girls, aged between 13 and 19, was interviewed. The teenagers completed a questionnaire, including measures of empathy, prosocial behaviour and family and peer relationship variables. In our results, we can point out our finding of a relationship between prosocial behaviour and empathy. Furthermore, it is worth noticing that there is a clear link of family and peer relationships with prosocial behavior as well as with empathy. Also, as has already been suggested in previous scientific literature, we find higher levels of prosocial behaviour and empathy in girls than in boys.Ministerio de Ciencia y Tecnología BSO2002-03022BSO2002-0302