Search results for "CERAMICS"
showing 10 items of 1599 documents
Mechanical, thermal and electrical properties of nanostructured CNTs/SiC composites
2018
International audience; Dense SiC-based nanostructured composites reinforced by well-distributed carbon nanotubes (CNTs) were elaborated for the first time by spark plasma sintering (SPS) without sintering additive. Microstructures of materials containing different amounts of CNTs – up to 8.0 vol% – were correlated with their mechanical, electrical and thermal properties. A continuous decrease of the SiC grain size was observed when the amount of CNT was increased, while the evolution of density showed a different behavior that could be explained by the particular combination of SPS technique with the electrical resistivity evolution of the green bodies. Optimal effect of CNTs addition on h…
Multilayer capsules: a promising microencapsulation system for transplantation of pancreatic islets
2001
In 1980, Lim and Sun introduced a microcapsule coated with an alginate/polylysine complex for encapsulation of pancreatic islets. Characteristic to this type of capsule is, that it consists of a plain membrane which is formed during a single procedural step. With such a simple process it is difficult to obtain instantly a membrane optimized with respect to all the properties requested for islet transplantation. To overcome these difficulties, it is recommended to build up the membrane in several consecutive steps, each optimized for a certain property. In this study, we have analysed such a multilayer microcapsule for the encapsulation of pancreatic islets. Therefore, empty and islet contai…
Synthesis and luminescent properties of Mn-doped alpha-tricalcium phosphate
2021
This project has received funding from European Social Fund (project No 09.3.3-LMT-K-712-19-0069) under grant agreement with the Research Council of Lithuania (LMTLT). Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART². The World Federation of Scientists is highly acknowledged for the National Scholarship to AZ. © 2021. This work is licensed under a CC BY-NC-ND 4.0 license.
Catalytic asymmetric conjugate addition of terminal alkynes to β-trifluoromethyl α,β-enones.
2014
The first enantioselective conjugate alkynylation of β-trifluoromethyl α,β-enones using terminal alkynes and a taniaphos–Cu(I) complex as catalyst is described. Ketones bearing a trifluoromethylated propargylic chiral centre in the β-position were obtained with good yields and high enantiomeric excesses (up to 99%).
Highly enantioselective copper(I)-catalyzed conjugate addition of 1,3-diynes to a,b-unsaturated trifluoromethyl ketones
2015
[EN] The conjugate diynylation of a,b-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol%) of a copper(I)–MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne. Pre-metalation of the terminal 1,3-diyne with stoichiometric or higher amounts of dialkylzinc reagent is not required. The corresponding internal diynes bearing a propargylic stereogenic center are obtained with good yields and excellent enantioselectivities.
Distinct photodynamics of κ-N and κ-C pseudoisomeric iron(ii) complexes
2021
Two closely related FeII complexes with 2,6-bis(1-ethyl-1H-1,2,3-triazol-4yl)pyridine and 2,6-bis(1,2,3-triazol-5-ylidene)pyridine ligands are presented to gain new insights into the photophysics of bis(tridentate) iron(II) complexes. The [Fe(N^N^N)2]2+ pseudoisomer sensitizes singlet oxygen through a MC state with nanosecond lifetime after MLCT excitation, while the bis(tridentate) [Fe(C^N^C)2]2+ pseudoisomer possesses a similar 3MLCT lifetime as the tris(bidentate) [Fe(C^C)2(N^N)]2+ complexes with four mesoionic carbenes. Financial support from the Deutsche Forschungsge-meinschaft [DFG, Priority Program SPP 2102] "Light-controlled reactivity of metal complexes" (BA 4467/7-1, LO 714/11-1, …
Hydrogen activation with perfluorinated organoboranes: 1,2,3-tris(pentafluorophenyl)-4,5,6,7-tetrafluoro-1-boraindene
2013
The perfluorinated boraindene was synthesized and fully characterized. Both computational and crystallographic data show that is antiaromatic. Compound was shown to react reversibly with H2 and to catalyse the hydrogenation of cyclohexene. The mechanism of catalysis was probed experimentally and computationally.
Educación artística : revista de investigación
2020
¿Qué es la cerámica? ¿Qué nos enseña de nosotros? ¿Está presente en nuestro entorno próximo y lo dota de identidad? ¿Qué de interés nos puede ofrecer en el ámbito educativo de primaria? ¿Qué campos de la expresión artística puede favorecer? Son algunas de las preguntas y reflexiones planteadas que motivan este ejercicio y tratamos de averiguar. Los alumnos de tercero de Magisterio realizan dos piezas cerámicas utilitarias de distinto método de conformación y acabado, reflexionando sobre la educación artística, la creación y los procesos propios de la cerámica. Para elaborarlas, se ha completado un proceso íntegro cerámico; partiendo de bocetos previos con una base gráfica tanto de forma com…
Hybrid materials with nanoscopic anion-binding pockets for the colorimetric sensing of phosphate in water using displacement assays
2008
Mesoporous amino-functionalised solids containing certain dyes have been used as suitable anion hosts in displacement assays for the colorimetric signalling of phosphate in water. Amoros del Toro, Pedro Jose, Pedro.Amoros@uv.es
Reduction of tris(benzene-1,2-dithiolate)molybdenum(VI) by hydroxide ions in dry tetrahydrofuran solution.
2001
Tris(benzene-1,2-dithiolate)molybdenum(VI) reacts rapidly and quantitatively with tetrabutylammonium hydroxide to yield the corresponding Mo(V) and Mo(IV) complexes and hydrogen peroxide; the reaction has been executed in dry tetrahydrofuran where the reaction rate shows a fair dependence on complex and OH2 concentrations. Cervilla Avalos, Antonio, Antonio.Cervilla@uv.es ; Perez Pla, Francisco, Francisco.Perez@uv.es ; Llopis Jover, Elisa, Elisa.Llopis@uv.es