691 research outputs found
DOES SERVICE QUALITY MATTER IN MEASURING PERFORMANCE OF WATER UTILITIES?
Quality is a dimension of water services that has been repeatedly omitted in the study of performance of water utilities. In this paper, we make use of Data Envelopment Analysis techniques (DEA) to compute both conventional quantity-based and quality-adjusted indicators of technical efficiency for a sample of Spanish water utilities. The key assumptions are that a lack of quality (bad quality) can be regarded as a bad output, and the existence of a trade-off between quantity and quality. Our main results indicate that quality matters in measuring technical performance, the difference between conventional and quality-adjusted evaluations representing the opportunity cost of maintaining quality. Averages and distribution functions significantly differ between both assessments of performance, although water utilities do not seem to rank differently.water utilities; quality; Data Envelopment Analysis.
Does service quality matter in measuring performance of water utilities?
Quality is a dimension of water services that has been repeatedly omitted in
the study of performance of water utilities. In this paper, we make use of Data Envelopment
Analysis techniques (DEA) to compute both conventional quantity-based and
quality-adjusted indicators of technical efficiency for a sample of Spanish water utilities.
The key assumptions are that a lack of quality (bad quality) can be regarded as a bad
output, and the existence of a trade-off between quantity and quality. Our main results
indicate that quality matters in measuring technical performance, the difference between
conventional and quality-adjusted evaluations representing the opportunity cost of maintaining
quality. Averages and distribution functions significantly differ between both
assessments of performance, although water utilities do not seem to rank differently
Valencian Reconquest churches. Study of the archaeological remains found in the Algemesí Capilla de la Comunión.
[EN] The present paper deals with the examination and research to the vestiges of an ancient church discovered in the basement of the Algemesi Communion Chapel, dating back to the beginnings of Christianity in the city. Considering the disposition of the constructive elements and the documented historical facts that date back to the first parish in the 13th century, it was deduced that the remains found were part of a temple with diaphragmatic arches and a woody roof. These facts are the paradigm of the ecclesiastical architecture that prevailed, by its execution speed, in the kingdom of Valencia after Jaime I reconquest. The study includes the comparison with other buildings of the same nature that allowed reconstructing its hypothetical volume, as well as the analysis of the techniques and materials that shaped its structure. Its identification ascribes another example to the Valencian protogothic architecture.García Sentamans, J.; Fernández-Plazaola, I.; Ferrandis Montesinos, JV.; Sáez Landete, A. (2019). Valencian Reconquest churches. Study of the archaeological remains found in the Algemesí Capilla de la Comunión. Architecture Civil Engineering Environment. 12(4):37-50. https://doi.org/10.21307/ACEE-2019-050S375012
«Emulan el firmamento»: las joyas en la poesía de Quevedo
Within the framework of the importance of money in Quevedo, this paper aims to examine the presence of jewelry in Quevedo’s poetry from an artistic, intertextual and rhetorical perspective. Starting with some general considerations about the treasures in Quevedo’s work, it goes on to study some poems and a detailed commentary on the sonnet “Portrait of Lisi that he brought in a ring”.Dentro del marco de la importancia del dinero en Quevedo, en el presente trabajo se pretende examinar la presencia de las joyas en la poesía quevediana desde una perspectiva artística, intertextual y retórica. A partir de unas consideraciones generales sobre los tesoros en la obra de Quevedo, se pasa al estudio de algunos poemas y al comentario detallado del soneto “Retrato de Lisi que traía en una sortija”
Photon statistics in collective strong coupling: Nanocavities and microcavities
There exists a growing interest in the properties of the light generated by hybrid systems involving a mesoscopic number of emitters as a means of providing macroscopic quantum light sources. In this work, the quantum correlations of the light emitted by a collection of emitters coupled to a generic optical cavity are studied theoretically using an effective Hamiltonian approach. Starting from the single-emitter level, we analyze the persistence of photon antibunching as the ensemble size increases. Not only is the photon blockade effect identifiable, but photon antibunching originated from destructive interference processes, the so-called unconventional antibunching, is also present. We study the dependence of these two types of negative correlations on the spectral detuning between cavity and emitters, as well as its evolution as the time delay between photon detections increases. Throughout this work, the performance of plasmonic nanocavities and dielectric microcavities is compared: despite the distinct energy scales and the differences introduced by their respectively open and closed character, the bunching and antibunching phenomenology presents remarkable similarities in both types of cavitiesThis work has been funded by the European Research
Council under Grant Agreements No. ERC-2011-AdG 290981
and No. ERC-2016-STG-714870, the EU Seventh Framework
Programme (Grants No. FP7-PEOPLE-2013-CIG-630996
and No. FP7-PEOPLE-2013-CIG-618229), and the Spanish
MINECO under Contracts No. MAT2014-53432-C5-5-R and
No. FIS2015-64951-R, as well as through the “María de
Maeztu” programme for Units of Excellence in R&D (Grant
No. MDM-2014-0377)
Organic polaritons enable local vibrations to drive long-range energy transfer
Long-range energy transfer in organic molecules has been experimentally obtained by strongly coupling their electronic excitations to a confined electromagnetic cavity mode. Here, we shed light into the polariton-mediated mechanism behind this process for different configurations: donor and acceptor molecules either intermixed or physically separated. We numerically address the phenomenon by means of Bloch-Redfield theory, which allows us to reproduce the effect of complex vibrational reservoirs characteristic of organic molecules. Our findings reveal the key role played by the middle polariton as the nonlocal intermediary in the transmission of excitations from donor to acceptor molecules. We also provide analytical insights on the key physical magnitudes that help to optimize the efficiency of the long-range energy transferThis work has been funded by the European Research Council under
Grant Agreements No. ERC-2011-AdG 290981 and No. ERC-
2016-STG-714870, the EU Seventh Framework Programme
(FP7-PEOPLE-2013-CIG-630996 and FP7-PEOPLE-2013-
CIG-618229), and the Spanish MINECO under Contracts No.
MAT2014-53432-C5-5-R and No. FIS2015-64951-R, as well
as through the “María de Maeztu” programme for Units of
Excellence in R&D (MDM-2014-0377)
Enhancing photon correlations through plasmonic strong coupling
© 2017 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibitedThere is an increasing scientific and technological interest in the design and implementation of nanoscale sources of quantum light. Here, we investigate the quantum statistics of the light scattered from a plasmonic nanocavity coupled to a mesoscopic ensemble of emitters under low coherent pumping. We present an analytical description of the intensity correlations taking place in these systems and unveil the fingerprint of plasmon-exciton-polaritons in them. Our findings reveal that plasmonic cavities are able to retain and enhance excitonic nonlinearities, even when the number of emitters is large. This makes plasmonic strong coupling a promising route for generating nonclassical light beyond the single-emitter levelFP7 Ideas: European Research Council (IDEASERC)
(ERC-2011-AdG 290981, ERC-2016-STG-714870,
FP7-PEOPLE-2013-CIG-618229, FP7-PEOPLE-2013-CIG630996);
Ministerio de Economía y Competitividad
(MINECO) (FIS2015-64951-R, MAT2014-53432-C5-5-R,
MDM-2014-0377
Theory of energy transfer in organic nanocrystals
Recent experiments have shown that highly efficient energy transfer can take place in organic nanocrystals at extremely low acceptor densities. This striking phenomenon has been ascribed to the formation of exciton polaritons thanks to the photon confinement provided by the crystal itself. An alternative theoretical model that accurately reproduces fluorescence lifetime and spectrum measurements in these systems without such an assumption is proposed. The approach treats molecule–photon interactions in the weak-coupling regime, and describes the donor and acceptor population dynamics by means of rate equations with parameters extracted from electromagnetic simulations. The physical insight and predictive value of this model also enables the authors to propose nanocrystal configurations in which acceptor emission dominates the fluorescence spectrum at densities orders of magnitude lower than the experimental onesThis work was funded by the Spanish Ministry for Science, Innovation, and Universities — AEI grants RTI2018-099737-B-I00, PCI2018-093145 (through the QuantERA program of the European Commission), and MDM-2014-0377 (through the María de Maeztu program for Units of Excellence in R&D), and by the European Research Council under Grant Agreement ERC-2016-STG-714870. It was also supported by a 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundatio
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