Search results for " Transition"

Children’s Diet during the Early Stages of the Nutritional Transition. The Foundlings in the Hospital of Valencia (Spain), 1852–1931

2021

The nutritional transition brought about profound changes in the nutrition of the European population in the 19th and 20th centuries. The predominant consumption of cereals gave way to kilocalorie-, protein-, vitamin- and mineral-rich diets that involved a greater intake of animal products. However, not all population groups underwent this transition at the same pace

New Strategy to Reduce the Global Burden of Stroke

2015

The socioeconomic and health effect of stroke and other noncommunicable disorders (NCDs) that share many of the same risk factors with stroke, such as heart attack, dementia, and diabetes mellitus, is huge and increasing.1–4 Collectively, NCDs account for 34.5 million deaths (66% of deaths from all causes)3 and 1344 million disability-adjusted life years lost worldwide in 2010.2 The burden of NCDs is likely to burgeon given the aging of the world’s population and the epidemiological transition currently observed in many low- to middle-income countries (LMICs).5,6 In addition, there is low awareness in the population about these NCDs and their risk factors,7–10 particularly in LMICs.11 These…

Beyond Biodegradability of Poly(lactic acid): Physical and Chemical Stability in Humid Environments

2017

International audience; Poly(lactic acid) (PLA) is the most traded biodegradable and biobased material. It is largely used as ecofriendly substitute of conventional plastics. Nevertheless, one of the main limiting factors is its water sensitivity. PLA reacts with water and is hydrolyzed during time, which determines its performance. Limited information related to the hydrolysis mechanism driven by water in vapor state is available in scientific literature. Literature is mainly focused on the effects of water in liquid state. This lack of information is of significant importance, since PLA interacts with water in both phases. This work was aimed to give a full depiction of the chemical and p…

Shock control bump design optimization on natural laminar aerofoil

2011

The chapter investigates Shock Control Bumps (SCB) on a Natural Laminar Flow (NLF) aerofoil; RAE 5243 for Active Flow Control (AFC). A SCB approach is used to decelerate supersonic flow on the suction/pressure sides of transonic aerofoil that leads delaying shock occurrence or weakening of shock strength. Such an AFC technique reduces significantly the total drag at transonic speeds. This chapter considers the SCB shape design optimisation at two boundary layer transition positions (0 and 45%) using an Euler software coupled with viscous boundary layer effects and robust Evolutionary Algorithms (EAs). The optimisation method is based on a canonical Evolution Strategy (ES) algorithm and inco…

AlInN/GaN quantum wells for intersubband transitions

2005

Al(In)N/GaN Heterostructures for Intersubband Transitions

2005

AlInN Based Quantum Wells for Intersubband Transitions

2005

On the effect of pressure on the phase transition of polymer blends and polymer solutions: Oligostyrene–n-alkane systems

2001

Critical temperatures of some binary solutions of weakly interacting low molecular weight polystyrenes dissolved in linear alkanes (oligoethylenes) were measured over the range 0.1 to 100 MPa. While (dT/dP)crit along the upper critical solution (UCS) locus for a “typical blend” is positive, and for the “ typical solution” can be either positive or negative (but is usually negative), there is no essential difference between blend and solution. Rather, the difference in sign is a consequence of the location of the hypercritical point (that point in (T,P)crit space where (dT/dP)crit changes sign, [(dT/dP)crit = 0 and (d2T/dP2)crit>0], also called the double critical point, DCP), which is norma…

Input of P, N-(phosphanyl, amino)-ferrocene hybrid derivatives in late transition metals catalysis

2018

International audience; Unequally functionalized ferrocenes give access to valuable hemilabile reactivity in catalytic reaction. We address the synthesis of hybrid (P, N)-ferrocenyl compounds for which recent catalytic breakthrough applications have been reported, transversely in late transition metals chemistry. Palladium, nickel, rhodium, iridium, and emerging iron and gold catalysis are illustrated from selected examples, which include CC bond formation from cross-coupling and polymerization, allylic substitution, cyanation, hydroformylation, CH arylation and silylation and hydrogenation reactions.

Influence of melt flow and temperature on erosion of refractory and deposit formation in aluminium melting furnaces

2002

The deposition and erosion mechanism in induction-channel furnace for Al melting in alumino-silicate refractory is considered. The possibility of simultaneous erosion and deposition in the same cross-section of the channel is shown. The chemical reaction model causing the erosion of refractory is proposed. The erosion process is described by chemically active aluminium oxides while the deposition is caused by chemically stable aluminium oxides. The variations of erosion and deposition in the same cross-section of the channel are explained by variation of the thickness of laminar sub-layer along the perimeter.