Search results for "transition [photon]"

La comprensión e impulso de la Sostenibilidad: un requisito imprescindible para una acción educativa y ciudadana eficaz

2019

Diagnósticos concordantes de la actual situación de emergencia planetaria muestran la necesidad de una urgente transición a sociedades que hagan posible una vida justa y digna al conjunto de seres humanos y a las futuras generaciones, al tiempo que se protege la biodiversidad y se revierte la degradación del medioambiente. Esta problemática ha dado lugar a propuestas con distintas denominaciones -transición a la sostenibilidad, decrecimiento, crecimiento inclusivo… - generando controversias que pueden dificultar el establecimiento de una agenda común para hacer frente a los problemas. Proponemos por ello centrar el debate en analizar las medidas que se consideran necesarias, en particular p…

Bridging probability and calculus: the case of continuous distributions and integrals at the secondary-tertiary transition

2018

International audience; This paper focuses on two mathematical topics, namely continuous probability distributions (CPD) and integral calculus (IC). These two sectors that are linked by the formula P(a<=X<=b)=int_a^b f(x)dx are quite compartmented in teaching classes in France. The main objective is to study whether French students can mobilize the sector of IC to solve tasks in CPD and vice versa at the transition from high school to higher education. Applying the theoretical framework of the Anthropological Theory of the Didactic (ATD), we describe a reference epistemological model (REM) and use it to elaborate a questionnaire in order to test the capacity of students to bridge CPD and IC…

A Japanese Approach to Stages of Capitalist Development. What Comes Next?

2022

Thermal properties of multiferroic Bi1−xEuxFeO3 (х = 0–0.40) ceramics

2017

Abstract A study of thermal diffusion, heat capacity and thermal conductivity of multiferroic Bi 1−x Eu x FeO 3 (x = 0–0.4) within the range of 130–1200 K is reported. Modifying by admixture of Eu is found to change substantially the thermal anomalies of diffusion and thermal conductivity of the antiferromagnetic phase transition, to increase heat capacity over a wide range of temperatures and to shift the antiferromagnetic transition temperature. The excess heat capacity is shown being related to Schottky effect of three-level states. The mechanisms dominating thermal transfer of phonons at the phase transition and dependence of the mean free path of phonons on the temperature are determin…

Nanocomposites based on esterified colophony and halloysite clay nanotubes as consolidants for waterlogged archaeological woods

2017

We have designed an innovative protocol for the consolidation of waterlogged archaeological woods by using acetone mixtures of halloysite clay nanotubes and a chemically modified colophony (Rosin). Firstly, we have investigated the thermal properties of HNTs/Rosin nanocomposites, which have been prepared by means of the casting method from acetone. The HNTs content have been systematically changed in order to study the influence of the inorganic filler on the thermal stability and glass transition process of Rosin. We have observed that the thermal properties of the hybrids are affected by the specific HNTs/Rosin interactions. Then, acetone dispersions of HNTs/Rosin composites at variable f…

In vitro degradation of porous PLLA/pearl powder composite scaffolds

2013

Abstract The in vitro degradation behavior of poly- l -lactide (PLLA), PLLA/aragonite pearl powder and PLLA/vaterite pearl powder scaffolds was investigated. The scaffolds were soaked in phosphate buffer solution (PBS) up to 200 days. Scanning electron microscopy (SEM), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) were used to observe any degradation of the scaffolds. Degradation behaviors such as changes in pH, porosity, bulk density, water absorption, weight loss and mechanical properties were discussed. The results show that a gradual increase of the pH in composite scaffolds can decrease the rate of hydrolysis of PLLA. PLLA/vaterite and PLLA/aragonite…

The role of mitochondrial transition pore, and its modulation, in traumatic brain injury and delayed neurodegeneration after TBI

2009

Following severe traumatic brain injury (TBI), a complex interplay of pathomechanism, such as exitotoxicity, oxidative stress, inflammatory events, and mitochondrial dysfunction occurs. This leads to a cascade of neuronal and axonal pathologies, which ultimately lead to axonal failure, neuronal energy metabolic failure, and neuronal death, which in turn determine patient outcome. For mild and moderate TBI, the pathomechanism is similar but much less frequent and ischemic cell death is unusual, except with mass lesions. Involvement of mitochondria in acute post-traumatic neurodegeneration has been extensively studied during the last decade, and there are a number of investigations implicatin…

The European network for care of children with paediatric rheumatic diseases : Care across borders

2019

Objectives. To provide an overview of the paediatric rheumatology (PR) services in Europe, describe current delivery of care and training, set standards for care, identify unmet needs and inform future specialist service provision. Methods. An online survey was developed and presented to national coordinating centres of the Paediatric Rheumatology International Trials Organisation (PRINTO) (country survey) and to individual PR centres (centre and disease surveys) as a part of the European Union (EU) Single Hub and Access point for paediatric Rheumatology in Europe project. The survey contained components covering the organization of PR care, composition of teams, education, health care and …

Congenital hypothyroidism: A 2020-2021 consensus guidelines update-An ENDO-European Reference Network initiative endorsed by the European Society for…

2021

Background: An ENDO-European Reference Network (ERN) initiative was launched that was endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology with 22 participants from the ENDO-ERN and the two societies. The aim was to update the practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). A systematic literature search was conducted to identify key articles on neonatal screening, diagnosis, and management of primary and central CH. The evidence-based guidelines were graded with the Grading of Recommendations, Assessment, Development and Evaluation system, describing both the strength of recommendations and the quali…

Steady, periodic, quasi-periodic and chaotic flow regimes in toroidal pipes

2012

Incompressible flow in a toroidal pipe was investigated by direct numerical simulation. The curvature a/c (radius of the cross section / radius of the torus) was 0.3 or 0.1 and the bulk Reynolds number ranged between 3500 and 14 700. The study revealed a rich scenario of transition to turbulence. For the higher curvature a/c = 0.3, a supercritical transition from stationary to periodic flow (Hopf bifurcation) was observed at Re=4600. The periodic flow was characterized by a travelling wave which, in the whole periodic Re range, took the form of a varicose modulation of the twin Dean vortex rings, included 8 wavelengths along the axis of the torus, and exhibited instantaneous anti-symmetry a…