Search results for "Toe"
showing 10 items of 3824 documents
Context-dependent minimisation of prediction errors involves temporal-frontal activation
2020
According to the predictive coding model of perception, the brain constantly generates predictions of the upcoming sensory inputs. Perception is realised through a hierarchical generative model which aims at minimising the discrepancy between predictions and the incoming sensory inputs (i.e., prediction errors). Notably, prediction errors are weighted depending on precision of prior information. However, it remains unclear whether and how the brain monitors prior precision when minimising prediction errors in different contexts. The current study used magnetoencephalography (MEG) to address this question. We presented participants with repetition of two non-predicted probes embedded in cont…
Oxidation of CH4 over Pd supported on TiO2-doped SiO2: Effect of Ti(IV) loading and influence of SO2
2009
Titania-modified silicas with different weight% of TiO2 were prepared by sol-gel method and used as supports for Pd (1 wt%) catalysts. The obtained materials were tested in the oxidation of methane under lean conditions in absence and in presence of SO2. Test reactions were consecutively performed in order to evaluate the thermal stability and poisoning reversibility. Increasing amounts of TiO2 improved the catalytic activity, with an optimum of the performance for 10 wt% TiO2 loading. Moreover, the titaniacontaining catalysts exhibited a superior tolerance towards SO2 by either adding it to the reactants or feeding it as a pure pretreatment atmosphere at 350 8C. Catalysts were characterize…
Activity of SiO2 supported gold-palladium catalysts in CO oxidation
2003
Abstract Bimetallic Au-Pd catalysts supported on silica with different Au/Pd atomic ratios were prepared by simultaneous reduction of palladium and gold precursors by ethanol in the presence of the polymer, polyvinylpyrrolidone (PVP). Formation of alloyed particles was detected by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and CO chemisorption measurements. The catalysts were tested in the catalytic oxidation of CO using a plug–flow reactor. The CO conversion was determined as a function of temperature. The monometallic palladium and the palladium-rich catalysts behaved quite similarly and were the most active catalysts. …
CoMo catalysts supported on aluminosilicates: synergy between support and sodium effects
2004
Abstract The structural properties and the hydrodesulfurization (HDS) activity of sodium doped and sodium free CoMo catalysts supported on amorphous aluminosilicates (ASA) were investigated as a function of different SiO2:Al2O3 ratios. The support yielding the most active catalyst, (66% alumina) doped with different amounts of sodium, was used for a series of similar catalysts in order to study the effect of the alkali ion on the catalytic performance. The supports were prepared by sol–gel method and the catalysts were prepared by incipient wet impregnation method. The structure and the surface of the various samples were investigated by X-ray diffraction (XRD), temperature-programmed reduc…
Evaluar para transformar: evaluación de la docencia universitaria bajo el prisma de la sostenibilidad
2017
El objetivo principal de este estudio se dirige a diagnosticar el nivel de introducción de la sostenibilidad en las actividades docentes y facilitar la autoevaluación profesional del profesorado universitario desde criterios de sostenibilidad.El estudio está basado en la investigación evaluativa como metodología asociada al paradigma sociocrítico; se analizan los resultados de la aplicación de un cuestionario autodiagnóstico validado, dirigido al profesorado de las áreas científico-técnicas de la Universitat de València. En el proceso sistemático de recogida y análisis de la información se han aplicado criterios para garantizar la calidad del juicio emitido.Los resultados ofrecen un diagnós…
Profesors Voldemārs Fricbergs: personālais bibliogrāfiskais rādītājs
1983
Saturs: Priekšvārds. Fizikas un matemātika zinātņu doktors profesors Voldemārs Fricbergs /Andris Šternbergs /. Profesora V. Fricberga publicētie darbi. (1948.-1983.) Profesora V. Fricberga rediģētie darbi. V. Fricbergam izsniegtās (publicētas) autorapliecības. Profesora V. Fricberga vadītās disertācijas. Raksti par profesoru V. Fricbergu. Profesora V. Fricberga publicēto darbu alfabētiskais rādītājs. Personu rādītājs.
Defect incorporation in In-containing layers and quantum wells: Experimental analysis via deep level profiling and optical spectroscopy
2020
Abstract Recent studies demonstrated that the performance of InGaN/GaN quantum well (QW) light emitting diodes (LEDs) can be significantly improved through the insertion of an InGaN underlayer (UL). The current working hypothesis is that the presence of the UL reduces the density of non-radiative recombination centers (NRCs) in the QW itself: during the growth of the UL, surface defects are effectively buried in the UL, without propagating towards the QW region. Despite the importance of this hypothesis, the concentration profile of defects in the quantum wells of LEDs with and without the UL was never investigated in detail. This paper uses combined capacitance-voltage and steady-state pho…
Detection system for depth profiling of radiotracers
2002
A reliable and efficient detection system essentially needed in the depth profiling of radiotracers consisting of two large PIN-diode arrays has been constructed. The requirements put forward to the detector system and the ability of the PIN-diode array to meet these demands are discussed. A comparison to a conventionally used liquid scintillation detector is presented by measuring an as-implanted 31Si profile in amorphous T21 ceramic by both apparatuses.
Planar Bragg Grating Sensor for the Detection of CFC-11
2018
We demonstrate the fabrication of a highly sensitive opto-chemical sensor system based on cyclodextrin derivative functionalized planar Bragg gratings for an online in-situ detection and measurement of the environmentally harmful propellant trichlorofluoromethane in real-time.
SrTiO 3 -based perovskites: Preparation, characterization and photocatalytic activity in gas–solid regime under simulated solar irradiation
2015
Strontium titanate-based perovskites have been prepared in the presence of Y and Co with the aim to substitute Sr and Ti, respectively, in the ST crystalline structure. The obtained samples have been characterized by XRD, Raman spectroscopy, FE-SEM, XPS and tested as photocatalysts in two gas-solid regime reactions: (i) 2-propanol complete mineralization and (ii) propene partial oxidation, using a system simulating solar irradiation. All the tested samples resulted active as photocatalysts but with significant differences. The lattice substitution of Sr by Y displays a beneficial effect on the 2-propanol photodegradation. Conversely, the partial presence of cobalt on the ST surface, as Co-o…