Search results for "cycle"

Stretch-shortening cycle: a powerful model to study normal and fatigued muscle.

2000

Stretch-shortening cycle (SSC) in human skeletal muscle gives unique possibilities to study normal and fatigued muscle function. The in vivo force measurement systems, buckle transducer technique and optic fiber technique, have revealed that, as compared to a pure concentric action, a non-fatiguing SSC exercise demonstrates considerable performance enhancement with increased force at a given shortening velocity. Characteristic to this phenomenon is very low EMG-activity in the concentric phase of the cycle, but a very pronounced contribution of the short-latency stretch-reflex component. This reflex contributes significantly to force generation during the transition (stretch-shortening) pha…

Exergy recovery during LNG regasification: Electric energy production – Part one

2009

Abstract In liquefied natural gas (LNG) regasification facilities, for exergy recovery during regasification, an option could be the production of electric energy recovering the energy available as cold. In a previous paper, the authors propose an innovative process which uses a cryogenic stream of LNG during regasification as a cold source in an improved combined heat and power (CHP) plant. Considering the LNG regasification projects in progress all over the World, an appropriate design option could be based on a modular unit having a mean regasification capacity of 2 × 109 standard cubic meters/year. This paper deals with the results of feasibility studies, developed by the authors at DRE…

Cold recovery during regasification of LNG part one: Cold utilization far from the regasification facility

2010

The paper deals with cold recovery during LNG regasification. The applications analyzed pertain to the use in deep freezing agro food industry and in space air conditioning facilities in commercial sector (Supermarkets and Hypermarkets) of cold recovered from the regasification process. A modular LNG regasification unit is proposed having the regasification capacity of 2 billion standard cubic meters/year of gas and it is based on use of a Power Cycle working with Ethane, this unit allows operation of cold energy transfer, contained in LNG to be regasified, in a range of temperatures suitable for multipurpose use of cold, reducing regasification process irreversibility. Some electric energy…

Investigating diffuse CO2 degassing in tectonically active areas by groundwater

Gender differences in bicycle sharing system usage in the city of Valencia

2021

Abstract Bicycle sharing systems (BSS) in cities are an environmentally friendly alternative to fossil-fuel-based transport. Among the different factors that influence its use, the scientific literature points out that there are gender differences in the frequency of trips made. The present study analysed the movements of men and women who use the BSS in the city of Valencia during weekdays. Our database contained a total of 5,300,328 trips by users over a period of 4 years. Ridership networks were constructed through user's trips (arcs) between the bicycle exchange stations (nodes). Different parameters of centrality and density of the generated networks were calculated, and the Voronoi sp…

Environmental performance of wood pellets' production through life cycle analysis

2016

Abstract Forests play a key role as the source of an essential renewable material and/or fuel: wood. The aim of this study was to evaluate the environmental impacts related to high-quality pellet production for domestic heating following the LCA (life cycle assessment) methodology and considering a cradle-to-gate perspective in the Tuscany region. This is representative and interesting for Italian pellet factories and for similar factories located in Central Europe, considering the Italian contribution to the production capacity of that area. All of the activities involved, from wood extraction in no-industrial forests to packed pellet production, ready for delivery to final users, were tak…

Life Cycle Sustainability Assessment of a dish-Stirling Concentrating Solar Power Plant in the Mediterranean area

2021

Abstract Among the different renewable energy sources, solar energy shows the highest exploitation potential to satisfy a substantial portion of the worlds’ future energy demand, guaranteeing at the same time lower emissions than conventional energy providers. Much of this potential is usable thanks to Concentrating Solar Power (CSP) technologies, of which the dish-Stirling concentrator is the most efficient. Nevertheless, the production and installation phases of the dish-Stirling technology can have an environmental impact which motivated the assessment of the plant in the three dimensions of sustainability (environmental, economic and social). The present publication evaluated an existin…

La representación sindical en España: cobertura y límites

2018

El objetivo de este artículo es realizar una aproximación al sistema de representación unitaria en la empresa en España a partir de una explotación estadística de los datos de las elecciones sindicales. Se trata de conocer aspectos como el alcance de la representación unitaria, la participación de los asalariados y la audiencia electoral de los sindicatos, con el objetivo de delimitar su representatividad y legitimidad. Nuestro trabajo se centra en el análisis de los tres últimos períodos electorales (2003-2007, 2007-2012 y 2012-2015), con objeto de evaluar el impacto del ciclo económico sobre la representación de los asalariados. The objective of this article is to make an approach to the …

RESHAPING AS NOVEL CIRCULAR ECONOMY STRATEGY FOR SHEET METAL BASED END-OF-LIFE COMPONENTS

2022

Making materials consumes about 21% of the global energy demand a specifically metals production, it accounts for about 8% of total global energy consumption. In fact, in the past few decades, the use of lightweight alloys has become increasingly widespread in many major industrial sectors thanks to the weight reduction associated with their applications. Most lightweight materials like aluminum alloys are characterized by high-energy demands primary production cycles that are responsible for a relevant share of the global CO2 emissions. Circular economy strategies such us longer life, more intense use, repair, product upgrades, modularity, remanufacturing, component re-use and open/closed …

Dependence between aging treatments and residual stresses on composite laminate

2006

International audience; The objective of this paper is to study the influence of residual stresses due to fabrication conditions on the thermomechanical behavior of carbon/epoxy laminate structures (cross ply). These studied laminates have undergone various cycles of thermal aging. The addition of a post-cure cycle after the end of the initial cycle makes it possible to reduce the residual stresses level. The incremental hole-drilling method is used to measure the residual strain in the laminates. These measured strains and the numerical calibration coefficients obtained by the finite element method allow to calculating the residual stress distribution in composite depth. The obtained resul…