Evaluation of the Aerodynamic Effect of a Smooth Rounded Roof on Crosswind Stability of a Train by Wind Tunnel Tests

The advent of high-speed trains led to new issues and constraints for railway network manufacturers and operators. This is the case of crosswind effect, that occurs when train is running in strong wind conditions. The combination of train speed and wind speed generates a relative flow that affects the train stability. Wind tunnel tests on still railway vehicles (relative wind-train velocity in coincidence with absolute wind velocity) are mandatory according to Technical Specification for Interoperability (TSI) to ensure high-speed train safety. However, issues related to the correct evaluation of the full-scale aerodynamic behaviour of the trains can arise. In the present work, aerodynamic force and pressure coefficients measured in wind tunnel tests on a scaled model of ETR1000 high-speed train on single track ballast and rails are presented. The tests were performed in the GVPM wind tunnel of Politecnico di Milano. Results show that different flow behaviours can occur at high yaw angles when the train behaves like a bluff body depending on wind speed used during the test

A study of the influence of aerodynamic loads on the forces exchanged in a twistlock corner casting connection of flat-wagons

In this paper cross-wind effects on freight wagons are studied. A mathematical model of a freight train made up of a flat-car and one or two containers has been built defining the dynamical characteristics of the connection (twistlock-corner casting). Wind tunnel tests on a scaled model are then used to define the aerodynamic coefficients of the wagon, both in loaded and unloaded conditions, considering different trainset layouts. Wind forces are finally applied separately to the container and the flat-car in order to define the CWC of the wagon and to verify the maximum forces exchanged through the twistlock-corner casting connection. The results of the analysis showed that severe conditions with respect to the risk of rollover can be found as a result of a succession of empty and loaded wagons

Respostas a tecnologias de trigo nos anos de 1981 e 1982.

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Carbohydrate-derived amphiphilic macromolecules: a biophysical structural characterization and analysis of binding behaviors to model membranes.

The design and synthesis of enhanced membrane-intercalating biomaterials for drug delivery or vascular membrane targeting is currently challenged by the lack of screening and prediction tools. The present work demonstrates the generation of a Quantitative Structural Activity Relationship model (QSAR) to make a priori predictions. Amphiphilic macromolecules (AMs) "stealth lipids" built on aldaric and uronic acids frameworks attached to poly(ethylene glycol) (PEG) polymer tails were developed to form self-assembling micelles. In the present study, a defined set of novel AM structures were investigated in terms of their binding to lipid membrane bilayers using Quartz Crystal Microbalance with Dissipation (QCM-D) experiments coupled with computational coarse-grained molecular dynamics (CG MD) and all-atom MD (AA MD) simulations. The CG MD simulations capture the insertion dynamics of the AM lipophilic backbones into the lipid bilayer with the PEGylated tail directed into bulk water. QCM-D measurements with Voigt viscoelastic model analysis enabled the quantitation of the mass gain and rate of interaction between the AM and the lipid bilayer surface. Thus, this study yielded insights about variations in the functional activity of AM materials with minute compositional or stereochemical differences based on membrane binding, which has translational potential for transplanting these materials in vivo. More broadly, it demonstrates an integrated computational-experimental approach, which can offer a promising strategy for the in silico design and screening of therapeutic candidate materials

Autonomic function in amnestic and non-amnestic mild cognitive impairment : spectral heart rate variability analysis provides evidence for a brain–heart axis

Mild cognitive impairment (MCI) is a heterogeneous syndrome with two main clinical subtypes, amnestic (aMCI) and non-amnestic (naMCI). The analysis of heart rate variability (HRV) is a tool to assess autonomic function. Cognitive and autonomic processes are linked via the central autonomic network. Autonomic dysfunction entails several adverse outcomes. However, very few studies have investigated autonomic function in MCI and none have considered MCI subtypes or the relationship of HRV indices with different cognitive domains and structural brain damage. We assessed autonomic function during an active orthostatic challenge in 253 oupatients aged\u2009 65\u200965, [n\u2009=\u200982 aMCI, n\u2009=\u200993 naMCI, n\u2009=\u200978 cognitively normal (CN), neuropsychologically tested] with power spectral analysis of HRV. We used visual rating scales to grade cerebrovascular burden and hippocampal/insular atrophy (HA/IA) on neuroimaging. Only aMCI showed a blunted response to orthostasis. Postural changes in normalised low frequency (LF) power and in the LF to high frequency ratio correlated with a memory test (positively) and HA/IA (negatively) in aMCI, and with attention/executive function tests (negatively) and cerebrovascular burden (positively) in naMCI. These results substantiate the view that the ANS is differentially impaired in aMCI and naMCI, consistently with the neuroanatomic substrate of Alzheimer's and small-vessel subcortical ischaemic disease

Allergic anaphylactic risk in farming activities: A systematic review

Allergic disorders in the agriculture sector are very common among farm workers, causing many injuries and occupational diseases every year. Agricultural employees are exposed to multiple conditions and various allergenic substances, which could be related to onset of anaphylactic reactions. This systematic review highlights the main clinical manifestation, the allergens that are mostly involved and the main activities that are usually involved. This research includes articles published on the major databases (PubMed, Cochrane Library, Scopus), using a combination of keywords. The online search yielded 489 references; after selection, by the authors, 36 articles (nine reviews and 27 original articles) were analyzed. From this analysis, the main clinical problems that were diagnosed in this category were respiratory (ranging from rhinitis to asthma) and dermatological (eczema, dermatitis, hives) in nature, with a wide symptomatology (from a simple local reaction to anaphylaxis). The main activities associated with these allergic conditions are harvesting or cultivation of fruit and cereals, beekeepers and people working in greenhouses. Finally, in addition to the allergens already known, new ones have emerged, including triticale, wine, spider and biological dust. For these reasons, in the agricultural sector, research needs to be amplified, considering new sectors, new technologies and new products, and ensuring a system of prevention to reduce this risk.peer-reviewe

Avaliação do uso de tecnologias em lavouras de trigo na macrorregião da EMATER de Santa Maria - RS, 1981.

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Automated robust Anuran classification by extracting elliptical feature pairs from audio spectrograms

This is the autjor accepted manuscript. The final version is available from IEEE via the DOI in this recordEcologists can assess the health of wetlands by monitoring populations of animals such as Anurans (i.e., frogs and toads), which are sensitive to habitat changes. But, surveying anurans requires trained experts to identify species from the animals' mating calls. This identification task can be streamlined by automation. To this end, we propose an automatic frog-call classification algorithm and a smartphone application that drastically simplify the monitoring of anuran populations. We offer three main contributions. First, we introduce a classification method that has an average accuracy of 86% on a dataset of 736 calls from 48 anuran species from the United States. Our dataset is much larger and diverse than those of previous works on anuran classification. Second, we extract a new type of spectrogram feature that avoids syllable segmentation and the manual cleaning of the recordings. Our method also works with recordings of variable length. Third, our method uses GPS location and a voting scheme to reliably deal with a large number of species and high levels of noise.National Science Foundatio