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

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

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

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)

Platelet count and Interleukin 6 Gene polymorphism in healthy subjects

BACKGROUND: Interleukin 6 (IL-6) is thought to play important roles in the development of reactive thrombocytosis caused by inflammation by its stimulatory effect on megakaryocytopoiesis. A G/C polymorphism of the IL-6 gene at position -174 has been found to be associated to different transcription rates. Specifically, subjects with the CC genotype showed lower plasma IL-6 levels compared with GC or GG subjects. Given this difference in transcription rates of IL-6 we speculated on different platelet count according to this IL-6 polymorphism. METHODS: The G/C polymorphism of the IL-6 gene at position -174, serum IL-6 concentration and platelet count were prospectively analyzed in 59 (25 women) consecutive healthy subjects. RESULTS: Subjects who were homozygotes for the C allele at position -174 of the IL-6 gene (Sfa NI genotype) showed significantly lower platelet count than carriers of the G allele, despite similar age, sex, body mass index and proportion of smokers (205400 ± 44088 vs 239818 ± 60194, p = 0.047). This was in parallel to differences in peripheral white blood cell count (5807 ± 1671 vs 6867 ± 1192 × 10(9)/ml, p = 0.01). CONCLUSION: This is the first description, to our knowledge, of a genetical influence on basal platelet counts, which appears to be partially dependent on a polymorphism of the IL-6 gene, even in the absence of inflammation

Acetic acid induces a programmed cell death process in the food spoilage yeast Zygosaccharomyces bailii

Here we show that 320-800 mM acetic acid induces in Zygosaccharomyces bailii a programmed cell death (PCD) process that is inhibited by cycloheximide, is accompanied by structural and biochemical alterations typical of apoptosis, and occurs in cells with preserved mitochondrial and plasma membrane integrity (as revealed by rhodamine 123 (Rh123) and propidium iodide (PI) staining, respectively). Mitochondrial ultrastructural changes, namely decrease of the cristae number, formation of myelinic bodies and swelling were also seen. Exposure to acetic acid above 800 mM resulted in killing by necrosis. The occurrence of an acetic acid-induced active cell death process in Z. bailii reinforces the concept of a physiological role of the PCD in the normal yeast life cycle.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XX

fuzzySim: applying fuzzy logic to binary similarity indices in ecology

Binary similarity indices are widely used in ecology, for example for detecting associations between species occurrence patterns, comparing regional and temporal species assemblages, and assessing beta diversity patterns, including spatial and temporal species loss and turnover. Such indices have widespread applications in biogeography, global change biology and biodiversity conservation. Similarity indices are commonly calculated upon binary presence/absence (or sometimes modelled suitable/unsuitable) data, which are generally incomplete and more categorical than their underlying natural patterns. Probable false absences are disregarded, amplifying the effects of data deficiencies and the scale dependence of the results. Fuzzy occurrence data, with a degree of uncertainty attributed to localities where presence or absence cannot be safely assigned, could better reflect species distributions, compensating for incomplete knowledge and methodological errors. Similarity indices would therefore also benefit from accommodating such fuzzy data directly. This study proposes fuzzy versions of the binary similarity indices most commonly used in ecology, so that they can be directly applied to continuous (fuzzy) rather than binary occurrence values, thus producing more realistic similarity assessments. Fuzzy occurrence can be obtained with several methods, some of which are also provided. The procedure is robust to data source disparities, gaps or other errors in species occurrence records, even for restricted species for which slight inaccuracies can affect substantial parts of their range. The method is implemented in a free and open-source software package, fuzzySim, which is available for the R statistical software and under implementation for the QGIS geographic information system. It is provided with sample data and an illustrated tutorial suitable for non-experienced users

Tomato fruits: a good target for iodine biofortification

Iodine is a trace element that is fundamental for human health: its deficiency affects about two billion people worldwide. Fruits and vegetables are usually poor sources of iodine; however, plants can accumulate iodine if it is either present or exogenously administered to the soil. The biofortification of crops with iodine has therefore been proposed as a strategy for improving human nutrition. A greenhouse pot experiment was carried out to evaluate the possibility of biofortifying tomato fruits with iodine. Increasing concentrations of iodine supplied as KI or KIO3 were administered to plants as root treatments and the iodine accumulation in fruits was measured. The influences of the soil organic matter content or the nitrate level in the nutritive solution were analyzed. Finally, yield and qualitative properties of the biofortified tomatoes were considered, as well as the possible influence of fruit storage and processing on the iodine content. Results showed that the use of both the iodized salts induced a significant increase in the fruit’s iodine content in doses that did not affect plant growth and development. The final levels ranged from a few mg up to 10 mg iodine kg-1 fruit fresh weight and are more than adequate for a biofortification program, since 150 μg iodine per day is the recommended dietary allowance for adults. In general, the iodine treatments scarcely affected fruit appearance and quality, even with the highest concentrations applied. In contrast, the use of KI in plants fertilized with low doses of nitrate induced moderate phytotoxicity symptoms. Organic matter-rich soils improved the plant’s health and production, with only mild reductions in iodine stored in the fruits. Finally, a short period of storage at room temperature or a 30-min boiling treatment did not reduce the iodine content in the fruits, if the peel was maintained. All these results suggest that tomato is a particularly suitable crop for iodine biofortification programs