Search results for "dioxide"
showing 10 items of 1250 documents
The influence of lipid content and taxonomic affiliation on methane and carbon dioxide production from phytoplankton biomass in lake sediment
2021
The greenhouse gases methane (CH4) and carbon dioxide (CO2) are end products of microbial anaerobic degradation of organic matter (OM) in lake sediments. Although previous research has shown that phytoplankton lipid content influences sediment methanogenesis, current understanding on how OM quality affects methanogenesis is still limited. Such information is needed to more accurately assess how lake greenhouse gas emissions may change in response to anthropogenic activities. We cultured 11 phytoplankton species from five classes and studied how taxonomic identity, C : N ratio, lipid content, and fatty acid composition of phytoplankton biomass affects the CH4 and net CO2 production in anaero…
Supplementing air with CO2 stripped from recirculating aquaculture improves growth of two green microalgae in aquaculture wastewater
2023
To improve sustainability and to implement the principles of circular economy in aquaculture, we tested the possibility to boost the capture of nitrate by two green microalgal species from recirculating aquaculture system's (RAS) wastewater by supplementing air with carbon dioxide stripped from a RAS. Carbon dioxide addition increased cell densities of Monoraphidium griffithii and Haematococcus pluvialis in photobioreactors during 9-day growing periods. However, growth rates and nitrate uptake rates were only improved for M. griffithii. Addition of CO2 decreased pH of the medium with M. griffithii which likely also affected positively on algal growth and nutrient uptake. These laboratory sc…
A Computational Study of Adsorption of CO2, SO2, and H2CO on Free-Standing and Molybdenum-Supported CaO Films
2019
Oxide films play a significant role in a wide range of fields from catalysis to solar cell materials. CaO films are promising sorbents for many environmentally harmful molecules. Here, we report a systematic investigation of adsorption of CO2, SO2, and H2CO on bulk and Mo-supported CaO(100) films using density functional theory. Significant effects on adsorption energy, charge transfer to the molecules, and degree of the C−O bond activation were demonstrated on Mo-supported CaO films by changing the film thickness, composition, and the strength and direction of an applied external electric field. These findings are relevant for interpreting results from scanning tunneling microscopy of smal…
Side‐on Coordination in Isostructural Nitrous Oxide and Carbon Dioxide Complexes of Nickel
2021
Abstract A nickel complex incorporating an N2O ligand with a rare η2‐N,N′‐coordination mode was isolated and characterized by X‐ray crystallography, as well as by IR and solid‐state NMR spectroscopy augmented by 15N‐labeling experiments. The isoelectronic nickel CO2 complex reported for comparison features a very similar solid‐state structure. Computational studies revealed that η2‐N2O binds to nickel slightly stronger than η2‐CO2 in this case, and comparably to or slightly stronger than η2‐CO2 to transition metals in general. Comparable transition‐state energies for the formation of isomeric η2‐N,N′‐ and η2‐N,O‐complexes, and a negligible activation barrier for the decomposition of the lat…
Mathematical modelling of sustainable bioresidual concrete
2019
In the production of cement, which is the main component of concrete production, the process generates about 5% of the global carbon dioxide emissions. In addition, bioproduct and pulp mills produce signi_cant quantities of soda ash and bio-ash, which is still largely unused. In this paper we will introduce our study related to improving the environmental friendliness of concrete used in construction by utilizing pulp mill waste while its long-term durability and strength and porosity properties meet the goals set for construction. The project `sustainable bioresidual concrete' is on-going and only preliminary numerical results with measurements are presented here. peerReviewed
Structurally simple complexes of CO2
2015
The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added products, particularly transportation fuels or fuel precursors. Implementation on a large scale could help to drastically reduce CO2 concentrations in the atmosphere. However, literature examples of weak…
La evolución energética del sector español de baldosas cerámicas
2014
espanolEl presente texto analiza como ha ido evolucionando el consumo y la eficiencia energetica de la industria espanola de baldosas ceramicas durante el siglo XX, y explora las posibilidades que se le plantean en el siglo XXI. Durante el pasado siglo este sector industrial acometio tres transiciones radicales al pasar de los combustibles tradicionales de biomasa a los hidrocarburos liquidos (fueloleo y gasoleo), y posteriormente a los gaseosos, principalmente gas natural. Aunque la informacion que permite evaluar de manera fiable la eficiencia energetica real en las plantas de fabricacion no es facil de obtener, los datos disponibles indican que se ha llegado a una elevada eficiencia con …
A novel and inexpensive method for measuring volcanic plume water fluxes at high temporal resolution
2017
© 2017 by the authors.Water vapour (H2O) is the dominant species in volcanic gas plumes. Therefore,measurements of H2O fluxes could provide valuable constraints on subsurface degassing and magmatic processes. However, due to the large and variable concentration of this species in the background atmosphere, little attention has been devoted to monitoring the emission rates of this species from volcanoes. Instead, the focus has been placed on remote measurements of SO2, which is present in far lower abundances in plumes, and therefore provides poorer single flux proxies for overall degassing conditions. Here, we present a new technique for the measurement of H2O emissions at degassing volcano…
Enhanced Heterogeneous Catalytic Conversion of Furfuryl Alcohol into Butyl Levulinate
2014
We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The catalyst is prepared via template-assisted sol-gel polycondensation of TEOS and MPTMS. It gives 96 % yield (and 100 % selectivity) of butyl levulinate in 4h at 110 °C. Reaction profiles before and after a hot filtration test confirm that the active catalytic species do not leach into the solution. The catalyst synthesis, characterization, and mode of operation are presented and discussed. Sour ca…
Exposure to nitrogen dioxide and respiratory health at 2 years in the INMA-Valencia cohort
2018
Resumen Objetivo Analizar la relación entre la exposición a dióxido de nitrógeno (NO2) en las etapas prenatal y posnatal y la incidencia de problemas respiratorios en niños/as hasta los 2 años de edad. Método La población consistió en 624 niños/as de la cohorte INMA-Valencia. Se estimó la exposición individual al NO2 en el exterior de la vivienda durante el periodo prenatal y hasta los 2 años de edad, a partir de la combinación de datos empíricos y el desarrollo de métodos geoestadísticos. Se aplicó un cuestionario para obtener la información sobre los síntomas respiratorios a los 2 años. La asociación entre la exposición al NO2 y los eventos respiratorios se realizó mediante regresión logí…