Search results for "Ford"

Electrochemical characterization of mangrove sediments: A proposal of new proxies for organic matter oxidation

2019

Abstract The voltammetric response of microparticulate deposits resulting from solvent evaporation of ethanolic extracts of mangrove sediments in contact with aqueous acetate buffer is hereby described. Dated sediment cores sampled from the Peruvian mangrove system (“Manglares de Tumbes” National Sanctuary) presented voltammetric responses dominated by oxidative signals of organic components that exhibit significant variations depending on the depth. Voltammetric data allowed for the definition of electrochemical indexes representative of the electrochemically oxidable organic matter fraction. These electrochemical indexes were fEAOM (for the total amount of organic matter being electrochem…

El tiempo en las clases de programación: ''Hacés y hacés y no te importa si tocó el timbre''

2021

A través de un estudio de caso en tres escuelas secundarias técnicas con orientación en programación se realizó una investigación cualitativa de corte etnográfica en la que se registraron los modos en que las y los estudiantes resuelven tareas de programación y organizan sus momentos de descanso. Recuperando las experiencias estudiantiles, se pudo observar cómo vivencian el tiempo cuando hay proyectos con desafíos cognitivos interesantes, en donde los cortes en su jornada escolar están fuertemente vinculados a la resolución de actividad escolar propuesta en vez de la estructura del horario escolar. Los recreos se ligan al sentido de la tarea, donde los descansos se vinculan a tres momentos …

Preferential CO oxidation over catalysts with well-defined inverse opal structure in microchannels

2008

Catalyst supports of CeO 2 /SiO 2 and Al 2 O 3 with three-dimensionally ordered macroporous structure were fabricated in microchannels by application of PMMA opals as templates. Pt-Rh supported on CeO 2 /SiO 2 showed high efficiency for CO removal in preferential CO oxidation in the presence of excess hydrogen. Pt-Rh supported on Al 2 O 3 with an inverse opal structure showed higher reactivity than that supported on wash-coated Al 2 O 3 layers in microchannel reactor.

Social Housing and Affordable Rent: The Effectiveness of Legal Thresholds of Rents in Two Italian Metropolitan Cities

2022

Social housing is an instrument of housing policies to support those groups of people who are disadvantaged due to particular economic weaknesses and/or social relational fragility. Consequently, to achieve the objective of social sustainability, the rents of social housing must be below the market rents and low enough to be affordable. Italian law has set several rent thresholds which are based on local territorial agreements between landlords and renters associations. This article aims to examine whether these thresholds generate social fairness and housing affordability within each city and between different cities, or instead inequalities and spatial asymmetries. A cluster analysis is a…

Renewable energy for sustainable rural development: synergies and mismatches

2020

Abstract Energy transition is increasingly regarded as a promising opportunity for the economic development of rural areas. This possibility is associated with the siting and (co-)ownership of decentralized (small-scale) renewable energy facilities. The underlying productive link, however, has been taken for granted, rather than conceptually and practically cultivated. Thus, while renewable energy-based rural development has been stated as a desired by-product of energy transitions, its potential has remained largely unfulfilled. This review aims to illuminate the ambiguous interplay between renewable energy and rural development in the context of the current trajectories of the energy tran…

La Semiótica en la Didáctica de la Matemática

2013

Kindergarten teachers’ orchestration of mathematical activities afforded by technology: agency and mediation

2016

This paper focuses on kindergarten teachers’ interactions with young children during mathematical learning activities involving the use of digital tools. We aim to characterise the teachers’ roles and actions in these activities and extend considerations of teachers’ orchestrations current in the research literature with regard to agency and mediation. Our analysis of teacher-children-digital tool interaction reveals that the kindergarten teachers took three roles in their work with young children, which we call Assistant, Mediator and Teacher roles. These roles were used interchangeably and purposefully by the kindergarten teachers. With regard to agency and mediation, we argue that agency…

The reciprocal link between music and movement studied through music-induced movements

2014

Music and movement are inseparable. The movements that are spontaneously procuded when listening to music are thought to be related to the close relationship between the perceptual and motor system in listeners. This particular link is the main topic of this thesis. A first approach was focused on the impact of music-induced movements on music cognition. In two studies, we show that moving along to music neither enhances the retention of new musical pieces (Study 1) nor the retention of the contextual information related to their encoding (Study 2). These results suggest a shallow processing inherent to the expression of musical affordances required for the production of music-induced movem…

Light absorption in silicon quantum dots embedded in silica

2009

The photon absorption in Si quantum dots (QDs) embedded in SiO2 has been systematically investigated by varying several parameters of the QD synthesis. Plasma-enhanced chemical vapor deposition (PECVD) or magnetron cosputtering (MS) have been used to deposit, upon quartz substrates, single layer, or multilayer structures of Si-rich- SiO2 (SRO) with different Si content (43-46 at. %). SRO samples have been annealed for 1 h in the 450-1250 °C range and characterized by optical absorption measurements, photoluminescence analysis, Rutherford backscattering spectrometry and x-ray Photoelectron Spectroscopy. After annealing up to 900 °C SRO films grown by MS show a higher absorption coefficient a…

DNA Oxidation Photoinduced by Norharmane Rhenium(I) Polypyridyl Complexes: Effect of the Bidentate N,N′-Ligands on the Damage Profile

2018

Re(I)--polypyridyl complexes have interesting and distinctive photochemical and photosensitizing properties. This work describes the capability to induce (or photoinduce) DNA damage of three Re(I)-complexes with a naturally occurring alkaloid called norharmane (nHo) as ligand: [Re(CO)₃ (nHo)(L)]CF₃ SO₃ where L=2,2'-bipyridine (ReBpy), phenanthroline (RePhen) or dipyrido[3,2-a:2',3'-c]phenazine (ReDppz). The interaction of the complexes with DNA was investigated by steady-state and time-resolved spectroscopy. Data show that the mode and strength of interaction depend on the chemical structure of the bidentate ligand. The complexes show a major static contribution to the overall interaction, …