Search results for "efficien"
showing 10 items of 3014 documents
Evaluating the Efficiency of Water Distribution Network Sectors Using the DEA-Weight Russell Directional Distance Model: The Case of the City of Vale…
2021
In many cities, sectorization projects of the drinking water distribution network have been implemented. This study provides a methodology to evaluate the efficiency of the sectors of a water distribution network by applying a data envelopment analysis weighted Russell directional distance (DEA-WRDD) model. This non-radial DEA model gives the overall efficiency of each unit of analysis, as well as each input, output, and undesirable output considered in the evaluation. The variables used in the analysis provide a multidisciplinary view: economic factors (covering costs), water quality parameters, and technical aspects. The empirical analysis was performed for the sectors of the water distri…
The Influence of Seasonality on the Economic Efficiency of Wastewater Treatment Plants
2010
Many tourist areas are often characterized with seasonal water demand. The influence of seasonality on water management is more intensive in the context of water scarcity. Thus the use of so-called non-conventional water resources in these areas becomes a key aspect. In this sense, efficient performance, both in technical and cost terms, favors water reuse possibilities and, therefore, increases the supply of non-conventional resources. In tourist areas, seasonality is a determining factor in the efficiency of wastewater treatment plants (WWTPs) as these are operating at full capacity only during the summer season while the rest of the year they have under-utilization problems. Using the Fr…
Emerging topics in scientific research on global water-use efficiency
2019
AbstractA bibliometric analysis of research articles published on water-use efficiency was performed using the Web of Science database and evaluated. Journal titles, publication years, subject categories, keywords and countries publishing were obtained. A number of 2077 papers were retrieved, two-thirds of them published in the last decade. The articles were published in 439 journals, with Agricultural Water Management, Agronomy Journal, Crop Science, Field Crops Research and Indian Journal of Agricultural Sciences the most productive. Most of the leading productive journals have Impact Factors in the top quartiles of the Journal Citation Reports. Agronomy, Plant Sciences, Water Resources a…
Dynamic wavefront sensing and correction with low-cost twisted nematic spatial light modulators
2010
Off-the-shelf spatial light modulators (SLMs), like twisted nematic liquid crystal displays (TNLCDs) used in projection systems, show some interesting features such as high spatial resolution, easy handling, wide availability, and low cost. We describe a compact adaptive optical system using just one TNLCD to measure and compensate optical aberrations. The current system operates at a frame rate of the order of 10 Hz with a four-level codification scheme. Wavefront estimation is performed through conventional Hartmann–Shack sensing architecture. The system has proved to work properly with a maximum rms aberration of 0. 76 μm and wavefront gradient of 50 rad/mm at a wavelength of 514 nm. The…
A pilot study on the differences in wavefront aberrations between two ethnic groups of young generally myopic subjects
2008
A comparative population-based cross-sectional study design was used to examine the prevalence of wavefront patterns in two different ethnic groups, and the relationship of these patterns with ocular biometrics and gender. The Shin–Nippon SRW5000 open field autorefractor, the Wavefront Analysis Supported Customized Ablation (WASCA) wavefront analyser and the IOLMaster were used to determine wavefront aberrations, mean spherical equivalent (SE) refractive error and axial length (AL). Seventy-four eyes from 74 young healthy subjects (44 British Asians, 30 Caucasians; 36 men, 38 women; mean age 22.51 ± 3.89 years) with mean SE averaging )1.90 ± 2.76 D (range )10.88 to +2.19 D) were examined. R…
Modelling of Laser Operation in RPE Nd3+:LiNbO3 Channel Waveguides
2006
In this work, laser action in RPE Nd3+:LiNbO3 is modelled by using the overlapping integrals method. Different pumping schemes, TE or TM, have been considered in order to reproduce the experimental measurements. Calculated results indicate that the slope efficiency remains basically independent on the pumping scheme while the threshold pump power increases for TE pumping.
Element weighted Kemeny distance for ranking data
2021
Preference data are a particular type of ranking data that arise when several individuals express their preferences over a finite set of items. Within this framework, the main issue concerns the aggregation of the preferences to identify a compromise or a “consensus”, defined as the closest ranking (i.e. with the minimum distance or maximum correlation) to the whole set of preferences. Many approaches have been proposed, but they are not sensitive to the importance of items: i.e. changing the rank of a highly-relevant element should result in a higher penalty than changing the rank of a negligible one. The goal of this paper is to investigate the consensus between rankings taking into accou…
Electrical Characterization of a Magnetic Tunnel Junction Current Sensor for Industrial Applications
2012
The objective of the work was the design of a Wheatstone bridge current sensor using MTJ as magnetoresistive elements. Each one of the four resistances of the bridge consists on 360 MTJ single elements connected in series for improved electrical robustness. A printed circuit board (PCB) was designed with a U-shaped copper trace placed under the PCB maintaining a 1.1 mm separation distance between sensor and trace. A 160% of tunnel magnetoresistance effect in the single junction and a 120% in its corresponding series elements connection has been achieved with a sensitivity of 9.2 Ω/Oe in a 65 Oe linear range. The DC sensor sensitivity in response to an external DC current sweeps of ±10, ±20,…
Transfer of aroma compounds in water-lipid systems: binding tendency of beta-lactoglobulin.
1998
Interactions of volatile aroma compounds with protein in aqueous solutions, especially whey proteins, have received significant attention in recent years. This work attempts to improve our understanding of the mass transfer in multiphasic systems, such as emulsions at the lipid−water interface, and to reveal the role of β-lactoglobulin in the release rate of solutes. For this purpose the rotating diffusion cell has been used. From a practical point of view it enables evaluation of the transfer through the aqueous phase, through the oil and the interfacial transfer. The effect of β-lactoglobulin, medium pH, and solute concentration has been investigated. Benzaldehyde and 2-nonanone have been…
Energy-aware design for wireless mesh networks
2014
International audience; Wireless mesh networks (WMNs) are the next step in the development of the wireless architecture, delivering wireless services for a large variety of users in personal, local, campus, and metropolitan areas. Energy efficiency solutions are becoming more vital for both local access networks and wireless networks and Green IT has attracted a considerable attention. However, the application of green network for wireless mesh networks has seldom been described in the literature. However, WMNs infrastructure devices are always active. Thus, during lower traffic periods the energy consumption is the same as in busy hours, while it would be possible to save a large amount of…