Influence of Embankments with Parapets on the Cross-Wind Turbulence Intensity at the Contact Wire of Railway Overheads

Winds as an environmental factor can cause significant difficulties for the railway system operation. The railway overhead has been particularly vulnerable to cross-winds related problems, such as development of undamped oscillations due to galloping phenomenon. The installation of windbreaks to decrease the aerodynamic loads on the train can affect the loads on railway overheads triggering cable galloping. One essential parameter to indicate the influence of the parapet wake on the catenary contact wire is the turbulence intensity. In this paper the results of an experimental analysis of the turbulence intensity due to the presence of parapets carried out in a wind tunnel are reported. Embankments equipped with different parapets have been tested and turbulence intensity has been measured at both contact wire locations, windward and leeward. The relative influence of the parapets is measured through a reduced turbulence intensity, defined as the ratio between the turbulence intensity measured with parapet and the turbulence intensity in the case without any parapet on the embankment. In general the reduced turbulence intensity increases as the height of the parapet increases

ARRAY TOMOGRAPHY:15 YEARS OF SYNAPTIC ANALYSIS

Synapses are minuscule, intricate structures crucial for the correct communication between neurons. In the 125 years since the term synapse was first coined, we have advanced a long way when it comes to our understanding of how they work and what they do. Most of the fundamental discoveries have been invariably linked to advances in technology. However, due to their size, delicate structural integrity and their sheer number, our knowledge of synaptic biology has remained somewhat elusive and their role in neurodegenerative diseases still remains largely unknown. Here, we briefly discuss some of the imaging technologies used to study synapses and focus on the utility of the high-resolution imaging technique array tomography (AT). We introduce the AT technique and highlight some of the ways it is utilised with a particular focus on its power for analysing synaptic composition and pathology in human post-mortem tissue. We also discuss some of the benefits and drawbacks of techniques for imaging synapses and highlight some recent advances in the study of form and function by combining physiology and high-resolution synaptic imaging

A simplified approach to determine aerodynamic damping of railway overheads

The railway overhead (or catenary) is the system of cables responsible for providing electric current to the train. This system has been reported as wind-sensitive (Scanlon et al., 2000), and particularly to the occurrence of galloping phenomena. Galloping phenomena of the railway overhead consists of undamped cable oscillations triggered by aerodynamic forces acting on the contact wire. As is well known, aerodynamic loads on the contact wire depends on the incident flow mean velocity and the angle of attack. The presence of embankments or hills modifies both vertical velocities profiles and angles of attack of the flow (Paiva et al., 2009). The presence of these cross-wind related oscillations can interfere with the safe operation of the railway service (Johnson, 1996). Therefore a correct modelling of the phenomena is required to avoid these unwanted oscillations

Relación entre el contrato temporal y la inteligencia emocional en los trabajadores de una empresa privada, Lima, 2020

El estudio tuvo como objetivo determinar la relación entre el contrato temporal y la inteligencia emocional en los trabajadores de una empresa privada Lima, 2020. La investigación realizó un diseño no experimental- transversal, de tipo básico, con un enfoque cuantitativo, descriptivo y de tipo correlacional. Dicha investigación se manejó con una población de estudio de 60 personas, el cual estaba constituido por personal tanto asistencial como administrativo, el muestreo que se manejó es el no probabilístico de tipo censal debido a que no se tomó lo estadístico para extraer una muestra. Se manejó en la investigación realizada como técnica la encuesta y como instrumento un cuestionario para cada variable, constituido cada uno por 15 ítems de tipo politómicas, el cual fue validado por los expertos en la materia. Se concluyó que existe relación estadística entre el contrato temporal y la inteligencia emocional, a través de r = 0,294 y p= 0.023 entre las variables. La cual indicó que la relación entre ambas es positiva baja y significativa

Extracting energy from Vortex-Induced Vibrations: A parametric study

Here, Vortex-Induced Vibrations (VIVs) of a circular cylinder are analyzed as a potential source for energy harvesting. To this end, VIV is described by a one-degree-of-freedom model where fluid forces are introduced from experimental data from forced vibration tests. The influence of some influencing parameters, like the mass ratio m∗ or the mechanical damping ζ in the energy conversion factor is investigated. The analysis reveals that: (i) the maximum efficiency ηM is principally influenced by the mass-damping parameter m∗ζ and there is an optimum value of m∗ζ where ηM presents a maximum; (ii) the range of reduced velocities with significant efficiency is mainly governed by m∗, and (iii) it seems that encouraging high efficiency values can be achieved for high Reynolds numbers

Alta incidência de pacientes com hipertensão arterial sistêmica descompensada na Equipe do PSF de Barra da Alegria no município de Indaiabira - MG

O presente trabalho originou-se a partir de observações feitas nas consultas e visitas domiciliares realizadas aos pacientes hipertensos cadastrados no Programa Hiperdia do povoado de Barra da Alegria do município de Indaiabira - MG. Conhece-se que a consulta médica, e as visitas domiciliares são ferramentas e espaços que os profissionais da saúde têm para o intercambio com os pacientes e conhecer seus hábitos e estilos de vida assim como assuntos relevantes de saúde-doença, monitorar a pressão arterial. Contudo foi possível observar que no povoado de Barra da Alegria os pacientes hipertensos estão descompensados porque não fazem o tratamento de forma direta e continua, não fazem dieta nem exercícios físicos. Assim, este estudo objetivou elaborar um plano de ação para tornar efetiva a compensação dos pacientes hipertensos do povoado de Barra da Alegria do município Indaiabira - MG. Para tal, realizou-se pesquisa no SciELO, com os descritores: hipertensão arterial sistêmica e Estratégia de saúde da família. Também foram consultados documentos do Ministério da Saúde. Espera-se que com a implementação do plano consigamos a compensação dos pacientes hipertensos

El efecto del capital económico, social y humano en el proceso de tránsito que realizan los migrantes guatemaltecos en busca del sueño americano

This thesis analyses the process in which Guatemalan migrants transit through Mexico towards the United States, emphasizing the role played by the financial, human and social capital, and taking into account the differences in gender and ethnicity. The specific objectives are i) to examine the social demographic profiles and trends of the migrants; ii) to estimate their numeric dimension; iii) to explore the impact of the policy of migration control applied by the Mexican government; iv) to estimate the effect of the vulnerability and poverty levels with respect to the probability of overcoming the transit stage; v) to know who are more exposed to face risks and under what circumstances; vi) to investigate human rights violations and violence experienced by migrants; vii) to analyze the differences in the possession and use of the financial, human and social capital that depend on gender and ethnicity. A methodological triangulation was performed, using quantitative data from the microdata obtained in the Encuesta sobre Migración en Frontera Guatemala-México (EMIF Sur) and the American Community Survey (ACS), among others; as well as qualitative data from interviewed migrants who passed through Mexico.FdA – Publicaties niet-programma gebonde