La reconstrucción del puente de Mostar en Bosnia-Herzegovina

[EN] Mostar Bridge is an unfortunate example of the macabre practice of destroying cultural heritage as a weapon against the ethnic enemy in the former Yugoslavia. The denouncement included in Loggia, Arquitectura & Restauración, no. 1 has the satisfaction of addressing the reconstruction of this symbol of World Heritage, which did not cease to be so even when its stones lay at the bottom of the Neretva River and nobody had any great hopes of reconstructing it.[ES] El puente de Mostar ha sido un desgraciado representante de la macabra práctica que ha tenido por objeto la destrucción del patrimonio cultural como arma contra el enemigo étnico en la antigua Yugoeslavia. La denuncia, recogida en Loggia, Arquitectura & Restauración nº 1, encuentra hoy un motivo de satisfacción en la reconstrucción de este símbolo Patrimonio de la Humanidad, que no dejó de serlo incluso cuando sus piedras estaban bajo las aguas del río Neretva, y no se albergaban esperanzas ciertas de reconstrucción.Romeo, M.; Roig, F. (2005). La reconstrucción del puente de Mostar en Bosnia-Herzegovina. Loggia, Arquitectura & Restauración. (18):18-37. doi:10.4995/loggia.2005.3403SWORD18371

Normatives de nova aplicació en la producció i comercialització de carn picada i preparats de carn

Treball presentat a la Facultat de Veterinària de la Universitat Autònoma de Barcelona.Treball presentat a l'assignatura de Deontologia i Veterinària Legal (21223

On the influence of inlet elbow radius on recirculating backflow, whoosh noise and efficiency in turbocharger compressors

[EN] While the influence of inlet geometry on turbocharger compressor behaviour has usually been investigated in terms of performance, surge margin and efficiency, data is scarce regarding the impact of the inlet flow field onto the noise emission. In many applications where tight packaging is required, a 90° elbow is placed just upstream of the compressor inducer. This can create a distortion of the incoming flow that affects the turbocharger operation; a distortion that is related to the radius of the elbow. In this experimental investigation three 90° elbow inlets are tested, measuring the in-duct sound intensity through acoustic beamforming, the spectral signature of the noise, and the distortion of the high temperature backflow typical of partially stalled conditions by means of thermocouple arrays. Results show that a tighter elbow radius not only impacts efficiency but also increases inlet noise at conditions close to surge. Spectral analysis shows that this increase is mainly produced in the form of a medium frequency broadband noise usually known as `whoosh¿ in the literature. On the other hand, effect on the outlet is less noticeable. Measurements of the recirculated backflow distortion in terms of circumferential skewness show good correlation with whoosh noise increase, indicating that flow distortion caused by tighter elbows at marginal surge conditions facilitates the transmission of whoosh noise oscillations to the inlet duct, worsening the acoustic behaviour of the system.The equipment used in this work has been partially supported by the Spanish Ministerio de Economia y Competitividad through grant DPI2015-70464-R and by FEDER project funds 'Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)' framed in the operational program of unique scientific and technical infrastructure of the Spanish Ministerio de Economia y Competitividad. F. Roig is partially supported through the Programa de Apoyo para la Investigacion y Desarrollo of Universitat Politecnica de Valencia (PAID-01-17).Broatch, A.; Ruiz, S.; Garcia Tiscar, J.; Roig-Villanueva, F. (2018). On the influence of inlet elbow radius on recirculating backflow, whoosh noise and efficiency in turbocharger compressors. Experimental Thermal and Fluid Science. 96:224-233. https://doi.org/10.1016/j.expthermflusci.2018.03.011S2242339

Nonuniform traffic distribution model in reverse link of multilaterate/multiservie WCDMA/based systems

This paper focuses on the modeling of the reverse link of a wideband code division multiple access system in a nonhomogeneous environment with a single cell. Multiple traffic spatial and service nonuniformities are considered in the analytical model, and then, expressions for required transmitted power and the associated outage probability and block error rate are derived. Special attention is also paid to the effect caused by different transmission bit rates and the spatial location of the traffic nonuniformities. From the presented expressions, it is possible to set appropriate load thresholds to control the desired error rate. Although the model considers a single cell, results in terms of maximum allowable load can also be applicable in multicell scenarios.Peer Reviewe

On the Design of Heat Exchangers for Altitude Simulators

[EN] Altitude simulators for internal combustion engines are broadly used in order to simulate different atmospheric pressure and temperatures on a test bench. One of the main problems of these devices is their outlet temperature and in order to control it, at least one heat exchanger is needed. A methodology to define, select and analyses the best heat exchanger that fulfill the requirements is presented. The methodology combines CFD and 0D models with experimental test. The combination of these tools allows to adjust both the 0D and the CFD models. The adjusted 0D model will be used to perform parametric analysis that will help to select the best geometrical combinations considering heat transfer and pressure losses while the CFD model will help to find possible local deficiencies on the designed Heat Exchanger and, therefore, try to improve it. Finally, the adjusted 0D model have been used to perform parametric studies changing the most important geometric characteristics to analyze the effect on HEX performance.Broatch, A.; Olmeda, P.; Garcia Tiscar, J.; Roig-Villanueva, F. (2021). On the Design of Heat Exchangers for Altitude Simulators. SAE International. 1-12. https://doi.org/10.4271/2021-01-038811

Dynamic mode decomposition of the acoustic field in radial compressors

[EN] Widely recognized since the beginning of air travel as a major issue, noise reduction remains nowadays a pressing concern for all stakeholders in the aviation industry. While aeroengine compressors, specially at the approach phase, have been historically identified as a leading source of noise, most of the research has been conducted on compressors of the axial type. However, radial compressors are found in a wide array of applications: smaller business jets, helicopters, unmanned aerial vehicles (UAVs), auxiliary power units (APUs), turbochargers for reciprocating engines, etc. Owing to their geometrical particularities, radial compressors feature flow patterns that differ from their axial counterparts, leading to different acoustic performance but also opening the door for different optimization approaches. Yet, classical modal decomposition techniques focused on duct propagation may fail to reveal the complex interactions between geometry and flow features that act as noise sources. In this paper we apply, in addition to the classical approach, a data-driven Dynamic Mode Decomposition (DMD) to pressure data coming from a Detached Eddy Simulation (DES), in which we have experimentally validated the correct reproduction of the modal behaviour of the compressor, thus obtaining in-depth details of the link between flow phenomena and noise generation and transmission across the inlet and outlet ducts. (C) 2019 Elsevier Masson SAS. All rights reserved.The equipment used in this work has been partially supported by the Spanish Ministerio de Economía y Competitividad through grant [DPI2015-70464-R] and by FEDER project funds Dotación de infraestructuras científico técnicas para el Centro Integral de Mejora Energética y Medioambiental de Sistemas de Transporte (CiMeT), [FEDER-ICTS-2012-06] framed in the operational program of unique scientific and technical infrastructure of the Spanish Ministerio de Economía y Competitividad. F. Roig is supported through the Programa de Apoyo para la Investigación y Desarrollo of the Universitat Politècnica de València [PAID-01-17].Broatch, A.; Garcia Tiscar, J.; Roig-Villanueva, F.; Sharma, S. (2019). Dynamic mode decomposition of the acoustic field in radial compressors. Aerospace Science and Technology. 90:388-400. https://doi.org/10.1016/j.ast.2019.05.015S3884009

Impact of simple surge-enhancing inlet geometries on the acoustic behaviour of a turbocompressor

[EN] This paper reports the results of an experimental campaign where four different inlet geometries for the compressor of an automotive turbocharger were acoustically characterized. These four geometries (a straight pipe for reference, a tapered duct, a 90º elbow and a reservoir) were selected for their potential for deep surge margin enhancement, while being simple enough to be commonly found in production vehicles. A detailed measurement of this surge margin enhancement was performed, together with acoustic measurements of both radiated and orifice noise at design conditions of best isentropic efficiency and also close to the deep surge limit. Results demonstrated that while all the proposed geometries indeed enlarged the usable air mass flow range, changes in the acoustic behaviour of the system could be positive, neutral, or even negative. It is therefore important to carefully consider accurate noise measurements before implementing these geometric solutions in production vehicles, and to further pursue research on the link between the characteristic flow pattern produced by each inlet geometry and the noise emission of the turbocompressor.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The equipment used in this work has been partially supported by FEDER project funds ‘‘Dotacio´n de infraestructuras cientı´fico te´cnicas para el Centro Integral de Mejora Energe´tica y Medioambiental de Sistemas de Transporte (CiMeT)’’ (grant number FEDER-ICTS-2012-06), framed in the operational program of unique scientific and technical infrastructure of the Spanish Government.Broatch, A.; Margot, X.; Garcia Tiscar, J.; Roig-Villanueva, F. (2018). Impact of simple surge-enhancing inlet geometries on the acoustic behaviour of a turbocompressor. International Journal of Engine Research. https://doi.org/10.1177/1468087418784125

Considerations on axial compressor bleed for sub-idle performance models

The trend towards increased bypass ratio and reduced core size in civil aero-engines puts a strain on ground-start and relight capability, prompting renewed interest in sub-idle performance modelling. While a number of studies have looked at some of the broad performance modelling issues prevalent in this regime, the effects that bleed can have on sub-idle performance have not been addressed in the literature. During start-up and relight, the unknown variation in bleed flows through open handling bleed valves can have a considerable impact on the compressor’s operating line. This paper combines experimental, numerical and analytical approaches to look at the effect that sub-idle bleed flows have on predicted start-up operating lines, along with their effect on compressor characteristics. Experimental whole-engine data along with a purpose-built core-flow analysis tool are used to assess the effect of bleed model uncertainty on engine performance models. An experimental rig is used to assess the effects of reverse bleed on compressor characteristics and measurements are compared against numerical results. Several strategies for the generation of sub-idle maps including bleed effects are investigated.European Union: Horizon 2020 Clean Sky 2 Joint Undertakin

Nondetection of SARS-CoV-2 on high-touch surfaces of public areas next to COVID-19 hospitalization units

We studied the contamination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the bacterial load of high-touch surfaces located in public areas next to coronavirus disease (COVID-19) hospitalization units. Ninety-two samples were obtained from 46 different high-touch surfaces: 36 sites next to COVID-19 hospitalization units and 10 sites in the cabins of the public elevators. SARS-CoV-2 was not detected at any site, despite high bacterial loads suggested that the studied sites had been frequently touched prior to the sampling