Listar QICM - Artículos por título
Mostrando ítems 13-32 de 182
-
Amorphous determination in calcium sulfoaluminate materials by external and internal methods
(ICE Publishing, 2014)External standard methodology has been successfully applied to quantify the known amounts of amorphous component that are increasingly added to cement-related materials. The consistency and accuracy of the methodology were ... -
Application of zeolites for the production of biofuels and furans from hexose sugars in ethanol.
(Elsevier, 2023-10-24)The use of zeolites as catalysts in the transformation of glucose and 5-hydroxymethylfurfural (HMF) into 5-ethoxymethylfurfural (EMF) was evaluated. The behaviour of the catalysts could be explained by their morphology, ... -
Assessment of ATR-FTIR spectroscopy with multivariate analysis to investigate the binding mechanisms of Ag and TiO2 nanoparticles to Chelex®-100 or Metsorb™ for the DGT technique
(The Royal Society of Chemistry, 2020-01-09)Studying nanomaterials' ecotoxicology is not new but there are still gaps in our understanding of their fate in the environment. A major challenge is lack of reliable tools to measure available concentrations of nanoparticles ... -
Assessment of the quantitative accuracy of Rietveld/XRD analysis of crystalline and amorphous phases in fly ash
(2017)An internal standard method based on Rietveld/XRD whole-pattern fitting analysis of fly ash is used to assess the quantitative accuracy to determine its crystalline and amorphous phases under various conditions such as ... -
Assessment of the stability of LTA zeolites under natural gas drying TSA conditions.
(Elsevier, 2023-10-17)The main features in cationic LTA zeolites that are likely to impact its potential hydrothermal stability are interconnected. The Al content and the compensating cation play an important role in the water adsorption but ... -
Belite cements and their activation
(Elsevier, 2020-11)Belite cements, BCs, containing mainly belite, alite and calcium aluminates, are currently used as low heat cements. These binders produce high amounts of C–S–H gel and have very good durability properties which are reviewed. ... -
Belite clinkers with increasing aluminium content: effect of calcium aluminates on calcium silicate hydration
(Elsevier, 2022)Belite cements (BCs) could have advantages over Portland cements concerning durability, low heat development and the use of less demanding raw materials. The activation of BCs by sulfur addition at the clinkering stage and ... -
Belite hydration at high temperature and pressure by in situ synchrotron powder diffraction
(2020-10-16)Portland cements are currently used as Oil‐Well‐Cements for the sheath between the metal casing and the borehole. At high pressures and temperatures, the resulting C-S-H gel(s) is partly unstable and it can react to give ... -
Bimetallic Niobium-Based Catalysts Supported on SBA-15 for Hydrodeoxygenation of Anisole
(ACS, 2021-12-17)The effect of adding iron, cobalt or nickel to a prepared niobium-supported catalyst using mesoporous silica SBA-15 as a support was evaluated in the hydrodeoxygenation (HDO) reaction of anisole, chosen as a model compound ... -
Boosting the Performance of La0.8Sr0.2MnO3-δ Electrodes by The Incorporation of Nanocomposite Active Layers
(Wiley, 2022-07-07)The use of active layers is a promising strategy to improve the properties of air electrodes for solid oxide fuel cells (SOFCs). In this work, La0.8Sr0.2MnO3-δ is combined with different oxide ion conductors Ce0.9Gd0.1O1.95, ... -
“Breathing” in Adsorbate-Responsive Metal Tetraphosphonate Hybrid Materials
(Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim, 2009-05-28)The structures of various layered calcium tetraphosphonates (CaH6DTMP; H8DTMP=hexamethyl- tetrakis(methylenephosphonic acid)), have been determined. Starting from CaH6DTMP·2H2O, thermal treatment and subsequent exposure ... -
C-S-H seeding activation of Portland and Belite cements: An enlightening in situ synchrotron powder diffraction study
(Elsevier, 2022-11)C-S-H seeding in Portland cements is well known from basic scientific works and field applications. Moreover, this activation approach could be beneficial for low-CO2 cements under development where a general drawback is ... -
Calcium aluminate cement conversion analysed by ptychographic nanotomography
(Elsevier, 2020-08-17)Calcium aluminate cements are used for special applications but are nowadays banned for general structural purposes due to the calcium aluminate hydrate conversion, that has led, for concretes fabricated with high water ... -
Catalytic Activity of Mixed Al2O3-ZrO2 Oxides for Glucose Conversion into 5-Hydroxymethylfurfural
(MDPI, 2020-08-04)In the present work, a series of catalysts based on aluminum and zirconium oxides was studied for the transformation of glucose into 5-hydroxymethylfurfural. These catalysts were characterized by using experimental techniques, ... -
Catalytic transfer hydrogenation of furfural to furfuryl alcohol over calcined MgFe hydrotalcites
(Elsevier B.V., 2019-11-07)Catalytic transfer hydrogenation is an alternative catalytic approach for the reduction of carbonyl groups, instead of the use of dihydrogen gas. In this sense, a series of catalysts has been prepared by thermal treatment ... -
Chemistry and Mass Density of Aluminum Hydroxide Gel in Eco-Cements by Ptychographic X-ray Computed Tomography
(ACS, 2017)Eco-cements are a desirable alternative to ordinary Portland cements because of their lower CO2 footprints. Some ye’elimite-based ecocements are attracting a lot of interest. Understanding the reasons for the mechanical ... -
Clinkering and hydration of belite-ye'elimite-alite cement
(Elsevier, 2017)Some belite-ye´elimite-ferrite (BYF) cements present low mechanical strengths mainly due to the slow reactivity of belite. A solution to this problem may be the activation of BYF clinkers by preparing them with a coexistence ... -
Common Structural Features in Calcium Hydroxyphosphonoacetates. A High-Throughput Screening
(2011-03-11)R,S-Hydroxyphosphonoacetic acid (H3HPA) is an inexpensive multidentate organic ligand widely used for the preparation of organo-inorganic hybrid materials. There are reports of several crystal structures and the variability ... -
A comparative study of experimental configurations in synchrotron pair distribution function
(MDPI - Publisher of Open Access Journals, 2019-04-25)The identification and quantification of amorphous components and nanocrystalline phases with very small crystal sizes, smaller than ~3 nm, within samples containing crystalline phases is very challenging. However, this ... -
Crystal engineering in confined spaces. A novel method to grow crystalline metal phosphonates in alginate gel systems
(The Royal Society of Chemistry, 2012)In this paper we report a crystal growth method for metal phosphonate frameworks in alginate gels. It consists of a metalcontaining alginate gel, in which a solution of phosphonate ligand is slowly diffused. Crystals of ...