Search results for "efficiency"
showing 10 items of 1430 documents
An institutional analysis of the implication of the MAS change process for the evolution of SMSC efficiency
2009
El objetivo general de este trabajo es conocer la relación existente entre el proceso de cambio de un Sistema de Contabilidad de Gestión (SCG) en las pequeñas y medianas empresas (PYME) y el éxito que genera dicho cambio. El éxito del cambio del SCG se va a medir a través de dos indicadores. El primer indicador, el éxito interno, medirá la distancia que existe entre las expectativas (qué se esperaba) de las nuevas técnicas de gestión implantadas y las realidades (qué son). El segundo indicador, el éxito externo, medirá la variación en el nivel de eficiencia relativa de la empresa dentro de su sector. La hipótesis básica de este estudio, plantea que el proceso de cambio puede explicar el niv…
A Decision support system for sustainable operations management in small power plants
2014
The importance of environmentally-friendly electricity production is recognized as one of the most important challenges of our future, covering a broad context of research topics and promoting future scenarios based on renewable energies and new technologies. In the short term, however, energy generation will still be largely relying on power plants fired with fossil fuels whose emissions of pollutants are regulated by the industrial emissions directive in the EU legislation. Such directive does not apply to small and medium combustion plants, which until now, have only been subject to national regulations. As part of its air quality package from December 2013, the EU Commission has propose…
Energy saving in wastewater treatment plants: A plant-generic cooperative decision support system
2017
Abstract In Europe, the analysis of Waste Water Treatment Plants (WWTPs) shows a significant energy efficiency potential (up to 25%). Optimistically, plant managers assess their plant efficiency once or twice per year. Consequently, the time gap between an inefficiency and its detection produces avoidable operational costs. Although the installation of multiple on-line sensors can provide detailed energy information, for a human operator it is unrealistic to analyse the produced data in a satisfactory time-scale. This paper proposes a cooperative tool for energy saving that remotely accesses and evaluates WWTP databases to produce daily energy assessment reports. The novelty of this decisio…
Stochastic multicriteria acceptability analysis using the data envelopment model
2006
Abstract Data envelopment analysis (DEA) and stochastic multicriteria acceptability analysis (SMAA-2) are methods for evaluating alternatives based on multiple criteria. While DEA is mainly an ex-post tool used for classifying alternatives into efficient and inefficient ones, SMAA-2 is an ex-ante tool for supporting multiple criteria decision-making. Both methods use a kind of value function where the importance of criteria is modeled using weights. Unlike many other methods, neither DEA nor SMAA-2 requires decision-makers’ weights as input. Instead, these so-called non-parametric methods explore the weight space in order to identify weights favorable for each alternative. This paper introd…
Perovskite CH3NH3PbI3–XClx Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence
2021
The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell degradation, spec-tral dependencies of open-circuit voltage (VOC), fill factor (FF) and the power conversion effi-ciency (PCE) have been acquired (for the first time reported in literature). Our custom-made measurement system allowed us to perform measurements of the above-mentioned entities in situ directly in vacuum during and after thermal deposition of the elec-trode. We also studied how these parameters in vacuum changed after cell exposure to ambient air for 85 min (50 nm top electrode) and for 180 min (100 nm top Ag electrode).…
Monitoring of renewable energy prototype for the DEDUENERT research project
2016
In this paper, we present a renewable energy sustainable micro-system installed upon a platform located in the Research and Technology Centre of Energy in Borj Cedria Techno park (Tunisia). This prototype has been conceived within the ENPI (European Neighborhood and Partnership Instrument) cross-border cooperation Italy-Tunisia 2007–2013 research project framework. This project's overall goal is to develop a common strategy for the deployment of renewable energy and energy efficiency by endorsing the cooperation between Italy and Tunisia. The focus is to implement the use of sustainable energy microsystems that generate electricity from various renewable sources (solar thermal, photovoltaic…
How do policies for efficient energy use in the household sector induce energy-efficiency innovation? : An evaluation of European countries
2017
Abstract Research on innovation induced by climate-mitigation policy has been focused predominantly on the supply side of the energy system. Despite considerable climate-mitigation potential on the demand side, less attention is given to the innovation effect of policies addressing the household sector. Based on a comprehensive data set, including 550 policy measures over 30 years (1980–2009) and covering 21 European countries, we find—based on econometric estimations—that policies targeting efficient energy use in the household sector significantly increase the number of patented energy-efficiency inventions. A comparison of the different policy types reveals a particularly strong influenc…
Cutting efficiency of heat-treated nickel-titanium single-file systems at different incidence angles.
2020
Cutting efficiency of Reciproc R25 (REC) and Reciproc blue R25 (REB) at different inclinations was evaluated. Sixty new files were tested at 90°, 70° and 45° of inclination in relation to the sample (n = 10), using a customised machine. All files were activated in reciprocation against standardised gypsum blocks for 120 s. Cutting efficiency was determined by measuring the block weight loss with an analytical balance and measuring the length of the block surface cut using a digital calliper. Data were statistically analysed (two-way ANOVA, Bonferroni t-test) with the significance level set at P < 0.05. There was no difference for REC among the tested angles. REB had no statistical differenc…
Catalytic Efficiency of a New Tridentate Ferrocenyl Phosphine Auxiliary: Sonogashira Cross-Coupling Reactions of Alkynes with Aryl Bromides and Chlor…
2005
[structure: see text] The catalytic activity in Sonogashira cross-coupling reactions of alkynes with a variety of aryl halides (including chlorides) using a multidentate ferrocenyl phosphine is presented. The novel mixed ferrocenyl aryl/alkyl triphosphine is thermally stable and insensitive to air or moisture, and its robustness allows aryl alkynylation at 10(-1) to 10(-4) mol % catalyst loadings with TONs up to 250,000. Copper-free coupling using phenylacetylene is also accessible in good yield.
Insights into how nucleotide supplements enhance the peroxidase-mimicking DNAzyme activity of the G-quadruplex/hemin system
2012
Since the initial discovery of the catalytic capability of short DNA fragments, this peculiar enzyme-like property (termed DNAzyme) has continued to garner much interest in the scientific community because of the virtually unlimited applications in developing new molecular devices. Alongside the exponential rise in the number of DNAzyme applications in the last past years, the search for convenient ways to improve its overall efficiency has only started to emerge. Credence has been lent to this strategy by the recent demonstration that the quadruplex-based DNAzyme proficiency can be enhanced by ATP supplements. Herein, we have made a further leap along this path, trying first of all to deci…