589 research outputs found
Optimized Design of Yb3+/Er3+-Codoped Phosphate Microring Resonator Amplifiers
A precise model to numerically analyse the performance of a highly Yb3+/Er3+-codoped phosphate glass microringresonator (MRR) is presented. This model assumes resonant behaviour inside the ring for both pump and signal powers and considers the coupled evolution of the rare earth (RE) ions population densities and the optical powers that propagate inside the MRR. Energy-transfer inter-atomic processes that become enhanced by required high-dopant concentrations have to be carefully considered in the numerical design. The model is used to calculate the performance of an active add-dropfilter and the more significant parameters are analysed in order to achieve an optimized design. Finally, the model is used to determine the practical requirements for amplification and oscillation in a highly Yb3+/Er3+-codoped phosphate glass MRR side-coupled to two straight waveguides for pump and signal input/output. In particular, the influence of dopant concentration, additional coupling losses and the structure symmetry are fully discussed
Coherent delocalization: Views of entanglement in different scenarios
The concept of entanglement was originally introduced to explain correlations
existing between two spatially separated systems, that cannot be described
using classical ideas. Interestingly, in recent years, it has been shown that
similar correlations can be observed when considering different degrees of
freedom of a single system, even a classical one. Surprisingly, it has also
been suggested that entanglement might be playing a relevant role in certain
biological processes, such as the functioning of pigment-proteins that
constitute light-harvesting complexes of photosynthetic bacteria. The aim of
this work is to show that the presence of entanglement in all of these
different scenarios should not be unexpected, once it is realized that the very
same mathematical structure can describe all of them. We show this by
considering three different, realistic cases in which the only condition for
entanglement to exist is that a single excitation is coherently delocalized
between the different subsystems that compose the system of interest
A Spatial Dynamic Model for Export Intensity of Hazardous Industrial Waste: The Incentive Effect of Regional Environmental Policies
This paper analyses, in the context of the Environmental Kuznet Curve, the determinants of export intensity of hazardous industrial waste among Spanish regions, with particular attention to the influence of waste taxes and of environmental policies. This study is carried out for the first time in the literature with a spatial dynamic model, fixed effects and panel data for the 17 regions (Comunidades Autónomas) of Spain during the period 2007–2017. The results suggest there is a spatial-dynamic component to export intensity, and that both regional taxes on waste disposal and environmental policy stringency appear to encourage, albeit modestly, the rate of exported waste to other regions. The model also shows that the more regions recycle, and the greater the economies of scale arising from industrial agglomeration, the lower is the region’s waste export intensity, although increasing restrictions on the international trade in hazardous waste have intensified trading inside the country. Finally, the results suggest a non-linear relationship between growth and export intensity, although apparently we are still far from the absolute decoupling of the Environmental Kuznet Curve. © 2021, The Author(s)
The interdependence of investment by different levels of government in a federal context
We use the Stochastic Frontier Approach to analyse for the first time the regions’ investment response to the central and local governments’ capital expenditure. The Spanish context is very interesting for this analysis because responsibilities are distributed between the three levels of government in a very interesting dual way: the distribution of spending responsibilities between central and regional governments corresponds to an exclusionary attribution of functions, while between regional and local levels, governments opt for cooperation. Results show that capital expenditure undertaken by the central government in the regions acts as substitute for regional investment, while capital expenditure by local governments appears to complement it. These results should be taken into account by public administrations when designing the distribution of responsibilities between different levels of government and their economic policy aims
Catalytic effect of capital transfers in a federal context: The case of spanish regions
There is a broad theoretical consensus on the effects of transfers (desired incentive impacts and induced adverse effects). But, as the literature review shows, there is not an accepted methodology for the empirical evaluation of these effects. The authors suggest a simple but rigorous empirical approach to quantify the catalytic effect of conditioned transfers for investment and their asymmetric impact across regions in Spain. To identify this behaviour, they have applied different empirical approaches with frontier techniques that let them consider the frontier as a proxy for potential investment. The results show that the conditioned transfers received by the regions from higher levels of government have a stimulus effect for investments, especially in the poor regions. The authors identify several factors explaining this unbalanced catalytic effect: the political cost of tax collection, political factors, inadequate management of debt, and other variables such as the level of economic development, population density, and the economic cycle
Tax effort of local governments and its determinants: The Spanish case
We have implemented frontier techniques to analyse the local tax effort and its determinants. The results show that municipalities have been quite responsible on average (tax efforts between 72-85 percent), although most municipalities can increase their tax efforts both making a more intensive use of their tax authority and improving the efficiency of their tax collection. To respond to the financing problems of municipalities near the tax frontier, it would be desirable to reform the legal framework to allow a greater tax capacity while leaving the decision on how to use this potential in hands of each unit of government
Review and analysis of vehicle stability models during floods and proposal for future improvements
This is the peer reviewed version of the following article: Bocanegra, RA, Vallés-Morán, FJ, Francés, F. Review and analysis of vehicle stability models during floods and proposal for future improvements. J Flood Risk Management. 2020; 13 ( Suppl. 1):e12551, which has been published in final form at https://doi.org/10.1111/jfr3.12551. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Flood water can affect vehicles significantly, which in turn can increase the negative effects of floods as vehicles are washed away by the flow and become a form of debris. In cities, most fatalities during floods occur inside vehicles. Consequently, it is necessary to establish thresholds for vehicle stability during this type of event to provide information necessary for flood risk management. This article analyses the available stability models developed over recent years to determine such thresholds. The stability models were grouped according to the way in which they approached car watertightness and the stability thresholds proposed by each of them were compared. It was found that these thresholds vary over a relatively wide range. Additionally, the experimental data were compared with the results provided by these studies leading to the conclusion that several of the stability models analysed do not fit measured data well. New research is required to overcome the simplifications made by the state-of-the-art models and to try to standardise the decision criteria which should be adopted to define stability thresholds for vehicles of different characteristics.Departamento Administrativo de Ciencia, Tecnologia e Innovacion COLCIENCIAS (Colombia) call 728-2015; Spanish Ministry of Science and Innovation through the research project TETISCHANGE, Grant/Award Number: RTI2018-093717-B-I00.Bocanegra, RA.; Vallés-Morán, FJ.; Francés, F. (2020). Review and analysis of vehicle stability models during floods and proposal for future improvements. Journal of Flood Risk Management. 13:1-13. https://doi.org/10.1111/jfr3.12551S11313Arrighi, C., Alcèrreca-Huerta, J. C., Oumeraci, H., & Castelli, F. (2015). Drag and lift contribution to the incipient motion of partly submerged flooded vehicles. Journal of Fluids and Structures, 57, 170-184. doi:10.1016/j.jfluidstructs.2015.06.010Arrighi C. Castelli F. &Oumeraci H.(2016). Effects of flow orientation on the onset of motion of flooded vehicles. InProceedings of the 4th IAHR Europe Congress. Liege DOI:https://doi.org/10.1201/b21902-140.Arrighi, C., Huybrechts, N., Ouahsine, A., Chassé, P., Oumeraci, H., & Castelli, F. (2016). Vehicles instability criteria for flood risk assessment of a street network. Proceedings of the International Association of Hydrological Sciences, 373, 143-146. doi:10.5194/piahs-373-143-2016Bonham A. J. &Hattersley R. T.(1967).Low level causeways. WRL Report No. 100. University of New South Wales. Sydney Australia.Cox R. J. Shand T. D. &Blacka M. J.(2010). Appropriate safety criteria for people in floods.Australian Rainfall and Runoff. WRL Research Report 240. Report for Institution of Engineers Australia.DROBOT, S., BENIGHT, C., & GRUNTFEST, E. (2007). Risk factors for driving into flooded roads. Environmental Hazards, 7(3), 227-234. doi:10.1016/j.envhaz.2007.07.003FitzGerald, G., Du, W., Jamal, A., Clark, M., & Hou, X.-Y. (2010). Flood fatalities in contemporary Australia (1997-2008). Emergency Medicine Australasia, 22(2), 180-186. doi:10.1111/j.1742-6723.2010.01284.xGordon A. D. &Stone P. B.(1973).Car stability on road causeways. WRL Technical Report No. 73/12. University of New South Wales. Sydney Australia.Jonkman, S. N., & Kelman, I. (2005). An Analysis of the Causes and Circumstances of Flood Disaster Deaths. Disasters, 29(1), 75-97. doi:10.1111/j.0361-3666.2005.00275.xKellar, D. M. M., & Schmidlin, T. W. (2012). Vehicle-related flood deaths in the United States, 1995-2005. Journal of Flood Risk Management, 5(2), 153-163. doi:10.1111/j.1753-318x.2012.01136.xKeller R. J. &Mitsch B.(1993).Safety aspects of the design of roadways as floodways. Research Report No. 69 Urban Water Research Association of Australia.Kramer, M., Terheiden, K., & Wieprecht, S. (2016). Safety criteria for the trafficability of inundated roads in urban floodings. International Journal of Disaster Risk Reduction, 17, 77-84. doi:10.1016/j.ijdrr.2016.04.003Martínez-Gomariz, E., Gómez, M., Russo, B., & Djordjević, S. (2016). Stability criteria for flooded vehicles: a state-of-the-art review. Journal of Flood Risk Management, 11, S817-S826. doi:10.1111/jfr3.12262Martínez-Gomariz, E., Gómez, M., Russo, B., & Djordjević, S. (2017). A new experiments-based methodology to define the stability threshold for any vehicle exposed to flooding. Urban Water Journal, 14(9), 930-939. doi:10.1080/1573062x.2017.1301501Mens M. J. Erlich M. Gaume E. Lumbroso D. Moreda Y. Van der VatM. &Versini P. A.(2008).Frameworks for flood event management. Report Number T19‐07‐03. WL Delft Hydraulics. Delft Netherlands.Moore, K. A., & Power, R. K. (2002). Safe Buffer Distances for Offstream Earth Dams. Australasian Journal of Water Resources, 6(1), 1-15. doi:10.1080/13241583.2002.11465206Oshikawa H. &Komatsu T.(2014). Study on the risk evaluation for a vehicular traffic in a flood situation.Proceedings of the 19th IAHR‐APD Congress Hanoi Vietnam.Pregnolato, M., Ford, A., Wilkinson, S. M., & Dawson, R. J. (2017). The impact of flooding on road transport: A depth-disruption function. Transportation Research Part D: Transport and Environment, 55, 67-81. doi:10.1016/j.trd.2017.06.020Shand T. Cox R. Blacka M. &Smith G.(2011).Australian Rainfall and Runoff (AR&R). Appropriate safety criteria for vehicles. Australian rainfall and runoff revision project 10: Report Number: P10/S2/020. Sidney Australia.Shu, C., Xia, J., Falconer, R. A., & Lin, B. (2011). Incipient velocity for partially submerged vehicles in floodwaters. Journal of Hydraulic Research, 49(6), 709-717. doi:10.1080/00221686.2011.616318Smith G. P. Davey E. K. &Cox R. J.(2014).Flood hazard. WRL Technical Report 2014/07. University of New South Wales. Sydney Australia.Smith G. P. Modra B. D. Tucker T. A. &Cox R. J.(2017).Vehicle stability testing for flood flows. WRL Technical Report 2017/07. University of New South Wales. Sydney Australia.Suarez, P., Anderson, W., Mahal, V., & Lakshmanan, T. R. (2005). Impacts of flooding and climate change on urban transportation: A systemwide performance assessment of the Boston Metro Area. Transportation Research Part D: Transport and Environment, 10(3), 231-244. doi:10.1016/j.trd.2005.04.007Teo, F. Y., Xia, J., Falconer, R. A., & Lin, B. (2012). Experimental studies on the interaction between vehicles and floodplain flows. International Journal of River Basin Management, 10(2), 149-160. doi:10.1080/15715124.2012.674040Versini, P.-A., Gaume, E., & Andrieu, H. (2010). Application of a distributed hydrological model to the design of a road inundation warning system for flash flood prone areas. Natural Hazards and Earth System Sciences, 10(4), 805-817. doi:10.5194/nhess-10-805-2010Versini, P.-A., Gaume, E., & Andrieu, H. (2010). Assessment of the susceptibility of roads to flooding based on geographical information – test in a flash flood prone area (the Gard region, France). Natural Hazards and Earth System Sciences, 10(4), 793-803. doi:10.5194/nhess-10-793-2010Xia, J., Falconer, R. A., Xiao, X., & Wang, Y. (2013). Criterion of vehicle stability in floodwaters based on theoretical and experimental studies. Natural Hazards, 70(2), 1619-1630. doi:10.1007/s11069-013-0889-2Xia, J., Teo, F. Y., Lin, B., & Falconer, R. A. (2010). Formula of incipient velocity for flooded vehicles. Natural Hazards, 58(1), 1-14. doi:10.1007/s11069-010-9639-
La belleza de lo inhomogéneo
The distribution of both residual stresses in the material and those due to an ophthalmic lens assembly can be analyzed using a tensiscope by means of the effect of the induced birefringence on polarized light passing through the lens. If a white light source is used the inhomogeneity generated in the material can result in images of remarkable beauty.
La distribución, tanto de las tensiones residuales en el material como de las debidas al montaje de una lente oftálmica, puede analizarse mediante un tensiscopio a partir del efecto de la birrefringencia inducida sobre luz polarizada que atraviese la lente. Si se utiliza una fuente de luz blanca la inhomogeneidad generada en el material puede dar lugar a imágenes de indudable belleza
The economic value of landscape aesthetics in Albufera natural park through the analytic multicriteria valuation method
[EN] The effective definition of public intervention goals and resource allocation for natural resource management requires decision makers to understand the monetary values of the full range of goods and services provided by landscapes, in other words, their Total Economic Value (TEV). Aesthetic enjoyment (AE) can be considered as part of such TEV of landscapes. For the estimation of the economic value of AE in Albufera Natural Park (Valencia, Spain), this paper applies the Analytic Multicriteria Valuation Method (AMUVAM). It is a combination of two established techniques: analytic hierarchy process (AHP) and discount cash flow (DCF). The economic value of non-market benefits under AMUVAM is obtained indirectly, by comparing the relative degrees of importance attached to the different components of TEV. In this way, not only does it estimate a monetary value of AE but also its importance relative to TEV. Results express that AE represents 7% of the TEV in Albufera Natural Park and 24% of the EV in Albufera Natural Park ( 176 million). Results reveal distinct patterns in the valuation of TEV and existence value (EV). In this way, together with the average, a range of values which show the different sensitivities of society is provided. The comparison of the TEV obtained for Albufera Natural Park with previous studies conducted on wetlands suggests its similarity in scale.Estruch-Guitart, V.; Vallés-Planells, M. (2017). The economic value of landscape aesthetics in Albufera natural park through the analytic multicriteria valuation method. International Journal of Design & Nature and Ecodynamics. 12(3):281-302. doi:10.2495/DNE-V12-N3-281-302S28130212
Personal Income Tax Compliance at the Regional Level: The Role of Persistence, Neighborhood, and Decentralization
This article quantifies personal income tax compliance by regions for the first time in Spain and identifies the factors explaining differences in tax compliance between regions, an aspect that has scarcely been analyzed in the literature. To this end, and in addition to the dynamic and spatial components considered by Alm and Yunus, this article considers the variables included in the classical tax evasion model of Allingham and Sandmo, as well as tax morale and political-institutional variables, including those linked to the country’s fiscal decentralization. The results obtained confirm, on one hand, those reached in the very extensive literature studying tax evasion from the individual perspective (including the importance of the dynamic element) and, on the other, the relevance of the spatial component in explaining tax compliance, so that greater or lesser tax compliance is partly explained by factors such as the tax behavior of neighbors or how those neighbors are treated by the public sector
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