Search results for "FLEX"

Naloxone inhibits not only stress-induced analgesia but also sympathetic activation and baroreceptor-reflex sensitivity

2012

Interactions between the sympathetic nervous system and pain are manifold and still have not been sufficiently characterized. Accordingly, several possible neuronal pathways have been described as being involved in mental stress-induced analgesia. We studied the role of the endogenous opioidergic system in stress-induced analgesia in 14 healthy participants in a double-blind cross-over trial. Naloxone or placebo was applied while electrical pain stimulation was started and electrical current increased. After reaching a constant stimulation at 30 mA, a color word interference test (Stroop task) was performed in a stressful and a non-stressful version. Blood pressure, heart rate and barorefle…

Acousto-optic interaction in polyimide coated optical fibers with flexural waves

2017

Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.

Acousto-optic Modulators Based on Flexural Acoustic Waves and its Application to Mode-locked Fiber Lasers

2014

Acousto-optic modulators based on flexural acoustic waves and its application to implement active mode-locking in fiber lasers is reported. Optical pulses as short as 25 ps temporal width were obtained at 2.46 MHz repetition rate.

Optimal design of steel frames accounting for buckling

2013

A formulation of a special design problem devoted to elastic perfectly plastic steel frame structures subjected to different combinations of static and dynamic loads is presented. In particular, a minimum volume design problem formulation is presented and the structure is designed to be able to elastically behave for the assigned fixed loads, to elastically shakedown in presence of serviceability load conditions and to prevent the instantaneous collapse for suitably chosen combinations of fixed and ultimate seismic loadings as well as of fixed and wind actions. The actions that the structure must suffer are evaluated by making reference to the actual Italian seismic code. The dynamic respon…

Shakedown optimal design of reinforced concrete structures by evolution strategies

2000

Approaches the shakedown optimal design of reinforced concrete (RC) structures, subjected to variable and repeated external quasi‐static actions which may generate the well‐known shakedown or adaptation phenomenon, when constraints are imposed on deflection and/or deformation parameters, in order to simulate the limited flexural ductility of the material, in the presence of combined axial stress and bending. Within this context, the classical shakedown optimal design problem is revisited, using a weak upper bound theorem on the effective plastic deformations. For this problem a new computational algorithm, termed evolution strategy, is herein presented. This algorithm, derived from analogy …

Fluorescence explorer (FLEX): An optimised payload to map vegetation photosynthesis from space

2006

The FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an ob…

Improved performance in flexible organic solar cells by using copolymeric phase-separation modulators

2018

One of the main problems related to the low performance of the organic solar cells (OSCs), concerns the low mobility of the materials constituting the heterojunction. Indeed, the poor charge transport in the active layer is the principal cause of a competition between separation and recombination of the photogenerated carriers. In this regard, a major obstacle to enhance OSCs efficiency is developing strategies to optimize the exciton dissociation and, consequently, the charge collection at the electrodes. Donor and acceptor systems must be well mixed on the length scale of 5 – 20 nm (exciton diffusion length) to meet the criteria for efficient exciton dissociation. In addition, the network…

Los 'think-tanks', miseria de ideas / 2

2008

Conflicting vocational identities and careers in the sector of tourism

2004

This article investigates the formation of vocational identities of workers in the sector of tourism in the Czech Republic, Greece and Spain. Major challenges and conflicts shape the sector of tourism as a particular labour space. Emerging issues relate to the need for diversifying the offer of services to face seasonality, strategies of entrepreneurial merging and demands for mobility and flexibility of the workforce. For the individual worker, a complex combination of related factors lead to tensions and contradictions, particularly in terms of changes in work organization, flexibility and how vocational identities of workers are shaped. An active policy for social dialogue and the improv…

The role of psychological inflexibility in adolescent satisfaction with the educational track and school dropout intentions

2022

This study aimed to obtain novel understanding of the associations between psychological inflexibility and adolescents' engagement with upper secondary studies. The participants were 885 Finnish adolescents (mean age 15.74 at the outset) whose psychological inflexibility was measured with the short form of the Acceptance and Fusion Questionnaire for Youth (AFQ-Y8) in the fall of the final (ninth) grade of basic education. School engagement was measured as satisfaction with the educational track and as school dropout intentions, and they were measured twice in the first study year after the transition to upper secondary education. The results showed that high psychological inflexibility in t…