Search results for "interfaces"

Segregation of copper oxide on calcium copper titanate surface induced by Graphene Oxide for Water splitting applications

2020

Abstract Photoelectrochemical cells (PEC) are promising devices for hydrogen production via sunlight energy. One of the important challenges in this area is to design photoactive electrodes able to absorb visible light. A good photoelectrochemical behavior depends on the presence of surface active sites to photogenerate current at the lower possible potential for water splitting. Recent investigations in this field are focusing on perovskite materials such as CaCu3Ti4O12 (CCTO) as visible light active electrode due its outstanding structure in which CCTO encloses in its structure a visible light absorbance component (CuO). The presence CuO on the material surface is mainly responsible for t…

Grafting and characterization of dodecylphosphonic acid on copper: Macro-tribological behavior and surface properties

2013

International audience; Thin film of n-dodecylphosphonic acid (DDPA) was prepared on a copper oxide substrate via a molecular self-assembly process. The composition, structure, organization, surface energy, morphology, and electrochemical behavior of the DDPA filmwere characterized bymeans of X-ray photoelectron spectroscopic analysis (XPS), polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), contact angle measurement v(CAM), microscopic observations, and electrochemistry. The friction behavior of the DDPA film adsorbed on copper oxide substrate sliding against a Si3N4 ball was examined on a linear reciprocating tribological tester. Worn surfaces of the DDPA film…

Co-participatory multimodal intergenerational storytelling : preschool children’s relationship with modality creating elder inclusion

2021

The COVID-19 crisis has highlighted elderly people as a vulnerable and excluded community, and connecting to the younger social media generation requires a shift in intergenerational storytelling performance. Recent research on multimodality has emphasized its benefits for the interactional process in storytelling. This study examines three aspects of storytelling – participation, multimodality, and emotional interaction – and uses co-creation and multimodal discourse analysis to investigate two questions: (1) To what extent can intergenerational storytelling benefit older people’s community engagement? (2) In a globalized world, how do children’s relationships with modalities create new l…

Dynamic segregation during ferrite oxidation revealed by XPS

2002

Dynamic segregation phenomena were revealed by XPS during the oxidation of some ferrites (Fe 2.5 Ti 0.5 O 4 , Fe 2.5 Ni 0.5 O 4 , Fe 2 CrO 4 and FeCr 2 O 4 ). This kind of phenomenon induces, at a low temperature (below room temperature), drastic changes in the cationic composition of the most external layers. Dynamic segregation is a function of the cationic composition, the oxidation capability and the morphology of these ferrites. Although dynamic segregation seems to be a quite frequent phenomenon that often can be observed during ferrite oxidation, there are materials in existence where it does not appear, such as molybdenum ferrite.

Magnetic alignment of aliphatic lamellae

1993

Abstract Magnetic alignment of mesophases is normally only considered possible when the molecule contains an aromatic ring system. In this paper we report on the mesomorphous behaviour of a polyalkylacrylate resin with average sidechain length 22 and the alignment of its lamellae in cast films by annealing in a strong magnetic field.

Why braille reading is important and how to study it /Por qué es importante la lectura en braille y cómo estudiarla

2016

AbstractDespite its relevance in theoretical and practical terms, braille reading has received little attention from researchers. Awareness of the pros and cons of the different procedures used to examine braille reading is needed to facilitate the realization of systematic studies and to improve teaching methods in braille reading. This study provides a critical examination of braille reading methods and highlights key points for future studies on tactile reading.

Studying social media as semiotic technology: a social semiotic multimodal framework

2018

How do we study social media technology? While social semiotics provides an extensive toolkit for analysing multimodal texts and semiotic practices, the study of social media as semiotic technology poses a significant challenge to existing research methodologies. In this article, we present a social semiotic framework that allows us to describe in analytical details the multimodal meaning potentials offered by digital social media technology and connect these to multimodal text-making and semiotic practices while underscoring the role of technology. Our framework is organized around seven interrelated and inherently informed dimensions: (1) multimodality, (2) practice, (3) the social, (4) m…

Quantifying and Processing Biomedical and Behavioral Signals

2019

A liquid alkoxide precursor for the atomic layer deposition of aluminum oxide films

2020

For large-scale atomic layer deposition (ALD) of alumina, the most commonly used alkyl precursor trimethylaluminum poses safety issues due to its pyrophoric nature. In this work, the authors have investigated a liquid alkoxide, aluminum tri-sec-butoxide (ATSB), as a precursor for ALD deposition of alumina. ATSB is thermally stable and the liquid nature facilitates handling in a bubbler and potentially enables liquid injection toward upscaling. Both thermal and plasma enhanced ALD processes are investigated in a vacuum type reactor by using water, oxygen plasma, and water plasma as coreactants. All processes achieved ALD deposition at a growth rate of 1-1.4 angstrom/cycle for substrate tempe…

Analysis of the linkages between rainfall and land surface conditions in the West African monsoon through CMAP, ERS-WSC, and NOAA-AVHRR data

2005

International audience; The European Remote Sensing Wind Scatterometer (ERS-WSC) backscattering coefficient, NOAA Advanced Very High Resolution Radiometer (NOAA-AVHRR) Normalized Difference Vegetation Index (NDVI), and Climate Prediction Center Merged Analysis Precipitation ( CMAP) precipitation data sets are studied over the period August 1991 to December 2000 to document ( 1) the interannual and intra-annual evolutions of vegetation photosynthetic activity and soil-vegetation water content over West Africa and ( 2) their two-way links with precipitation. Over the Sahel, at interannual timescales the strongest relationships between vegetation, soil moisture, and precipitation are observed …