2,886 research outputs found
Study of the mitigation of tram-induced vibrations on different track typologies
Nowadays there is a growing development of urban tram and underground networks with the aim of improving resident’s mobility and reducing the environmental impact. Among the issues related to this fact one finds the vibration generated by the vehicles and transmitted through the track and the ground. This may cause an important impact for both residents and structures. In order to study this phenomenon, a comprehensive campaign of measurements has been carried out in certain sections of the tram network in Alicante (Spain). In addition, an analytical model has been developed and calibrated with part of the data obtained. Using both experimental measures and the computer model vibration within the track is analyzed. Special attention is paid to the alleviation capability of the different materials and typologies present in the track. From this study, a strong relation between the Young Modulus and the frequency range alleviated by each material is obtained, and more rigid typologies are shown to be more efficient for low frequency vibrations which are the ones potentially disturbing for humans
Random attractors for stochastic 2D-Navier-Stokes equations in some unbounded domains
We show that the stochastic flow generated by the Stochastic Navier-Stokes
equations in a 2-dimensional Poincar\'e domain has a unique random attractor.
This result complements a recent result by Brze\'zniak and Li [10] who showed
that the flow is asymptotically compact and generalizes a recent result by
Caraballo et al. [12] who proved existence of a unique pullback attractor for
the time-dependent deterministic Navier-Stokes equations in a 2-dimensional
Poincar\'e domain
Railway traffic induced vibrations: comparison of analytical and finite element models
The recent increase in the use of the railway and the establishment of more restrictive policies of harmful environmental effects of railway transport highlights the need to investigate ground vibrations related to trains. Therefore models to evaluate how this phenomenon affects have been performed. This article aims to expose both analytical and 3D-FE models and to compare theoretical formulation and results. Models have been calibrated and validated with real data. Furthermore, a simulation of the acceleration level of different railway infrastructure elements has been achieved
Design and validation of a railway inspection system to detect lateral track geometry defects based on axle-box accelerations registered from in-service trains
Metropolitan railway transport has become an efficient solution to the mobility necessities in urban areas. Railway track maintenance tasks have to be improved and adjusted to metropolitan requirements, in particular the few hours available to operate due to the high frequency service offered. This paper describes and proposes an inertial monitoring system to detect and estimate track irregularities by using in-service vehicles. A new maintenance strategy is established, based on the railway track conditions and continuous monitoring is provided to do so. The system proposed consists of at least two accelerometers mounted on the bogie axle-box and a GPS (Global Positioning System). Lateral accelerations have been analyzed to study gauge and lateral alignment deviations. Accelerations have been treated and processed by high-pass filtering and validation has been carried out by comparison with measurements provided by a track monitoring trolley. Measurements were made on Line 1 of the Alicante metropolitan and tram network (Spain)
Trigger and readout electronics for the STEREO experiment
The STEREO experiment will search for a sterile neutrino by measuring the
anti-neutrino energy spectrum as a function of the distance from the source,
the ILL nuclear reactor. A dedicated electronic system, hosted in a single
microTCA crate, was designed for this experiment. It performs triggering in two
stages with various selectable conditions, processing and readout via UDP/IPBUS
of 68 photomultiplier signals continuously digitized at 250 MSPS. Additionally,
for detector performance monitoring, the electronics allow on-line calibration
by driving LED synchronously with the data acquisition. This paper describes
the electronics requirements, architecture and the performances achieved.Comment: Topical Workshop on Electronics for Particle Physics (TWEPP) 2015,
Lisboa. 9 pages, 9 figure
Bitemarks analysis of orthodontically treated suspects – an identification approach
Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio
AT1 Receptor Gene Polymorphisms in relation to Postprandial Lipemia
Background. Recent data suggest that the renin-angiotensin system may be involved in triglyceride (TG) metabolism. We explored the effect of the common A1166C and C573T polymorphisms of the angiotensin II type 1 receptor (AT1R) gene on postprandial lipemia. Methods. Eighty-two subjects measured daytime capillary TG, and postprandial lipemia was estimated as incremental area under the TG curve. The C573T and A1166C polymorphisms of the AT1R gene were determined. Results. Postprandial lipemia was significantly higher in homozygous carriers of the 1166-C allele (9.39 ± 8.36 mM*h/L) compared to homozygous carriers of the 1166-A allele (2.02 ± 6.20 mM*h/L) (P < 0.05). Postprandial lipemia was similar for the different C573T polymorphisms. Conclusion. The 1166-C allele of the AT1R gene seems to be associated with increased postprandial lipemia. These data confirm the earlier described relationships between the renin-angiotensin axis and triglyceride metabolism
Pre-operative predictors of red blood cell transfusion in liver transplantation
info:eu-repo/semantics/publishedVersio
Developing young people's sense of self and place through sport
Previous research has recognized positive health implications, both physical and mental, as an outcome of participation in leisure pursuits. They provide opportunities for self-expression and stress reduction, as well as an environment in which people can socialize. Leisure activities, specifically sport activities, can play a significant role in young people's identity development. This paper explores the leisure activities in which young people in Adelaide, Australia participate. It examines the role of leisure activities in terms of young people's identity and feelings towards their hometown. This study consisted of semi-structured focus groups conducted with 24 senior high school students, followed by a survey resulting in 226 useable responses. Respondents were aged between 16 and 18 years of age. From the range of activities identified and explored, the results revealed sports activities to have the greatest impact on young people's lives. The results demonstrated that frequency of participation has a significant effect on young people's involvement levels and how they identify with the activity
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