Serviceability response of a bench-mark cable-stayed footbridge: comparison of available methods

In previous Footbridge Conferences, the focus of researchers has been on the representation of pedestrian actions (vertical and lateral) to design footbridges, on the proposal of methodologies for the analysis in service of these structures and on the description of the serviceability response of particular footbridges. Nonetheless, none of these research works have been focused on the magnitude of the serviceability response of footbridges according to its structural type. This paper characterises the response of footbridges with stayed cables as main structural type. Based on a compiled dataset of cable-stayed footbridges (developed for this research work), the paper presents the geometrical and structural characteristics of a footbridge that can be regarded as representative of this structural type. Considering the best methodologies available for the assessment of its response in vertical and lateral direction, the paper describes the magnitude of the serviceability performance of this bridge under a wide range of pedestrian scenarios. This description familiarises designers at early stages of their design with the order of magnitude of the serviceability response of cable-stayed footbridges with an arrangement similar to that commonly used for this structural type

Serviceability limit state of vibrations in under-deck cable-stayed bridges accounting for vehicle-structure interaction

Verification of the serviceability limit state of vibrations due to traffic live loads can be neglected in conventional types of concrete road bridges but becomes critical in the design of slender structures like under-deck cable-stayed bridges. The novelty of the work presented in this article is that an innovative vehicle-bridge interaction model is employed, in which realistic wheel dimensions of heavy trucks, road roughness profiles and the cross slope of the road are considered in nonlinear dynamic analyses of detailed three-dimensional finite element models. An extensive parametric study is conducted to explore the influence of the bridge parameters such as the longitudinal and transverse cable arrangement and the support conditions, in addition to the load modelling, road quality, the wheel size, the transverse road slope and the vehicle position and speed on the response of under-deck cable-stayed bridges. It has been observed that the vibrations perceived by pedestrians can be effectively reduced by concentrating the cable-system below the deck at the bridge centreline. The Fourier amplitude spectrum of the acceleration at critical positions along the deck proved that the response of under-deck cable-stayed bridges is not dominated only by contributions at the fundamental mode and, consequently, the conventional deflection-based methods are not valid to assess the users comfort. Instead, Vehicle-Bridge Interaction analyses are recommended for detailed design, considering the wheel dimensions if the pavement quality is bad and/or if the wheel radius is large. Finally, we verify through multiple approaches that the comfort of pedestrian users is more critical than that of vehicle users. However, the comfort of vehicle users is shown to be significantly affected when the road quality is poor

Experimental assessment and constitutive modelling of rubberised concrete materials

This paper focuses on examining the uniaxial behaviour of concrete materials incorporating rubber particles, obtained from recycled end-of-life tyres, as a replacement for mineral aggregates. A detailed account of a set of material tests on rubberised concrete cylindrical samples, in which fine and coarse mineral aggregates are replaced in equal volumes by rubber particles with various sizes, is presented. The experimental results carried out in this investigation, combined with detailed examination of data available from previous tests on rubberised concrete materials, show that the rubber particles influence the mechanical properties as a function of the quantity and type of the mineral aggregates replaced. Experimental evaluation of the complete stress-strain response depicts reductions in compressive strength, elastic modulus, and crushing strain, with the change in rubber content. Enhancement is also observed in the energy released during crushing as well as in the lateral strain at crushing, primarily due to the intrinsic deformability of the interfacial clamping of rubber particles which leads to higher lateral dilation of the material. The test results and observations enable the definition of a series of expressions to estimate the mechanical properties of rubberised concrete materials. An analytical model is also proposed for the detailed assessment of the complete stress-strain response as a function of the volumetric rubber ratio. Validations performed against the material tests carried out in this study, as well as those from previous investigations on rubberised concrete materials, show that the proposed models offer reliable predictions of the mechanical properties including the full axial and lateral stress-strain response of concrete materials incorporating rubber particles

Transformación antropológica en mayores con diabetes tipo II a través del ejercicio: pilates y ejercicio aeróbico

Estimations are that 285 million people suffer from Type 2 diabetes, or 6% of the world's adult population and 60 million people in the EU (10% of population). Spain’s population 47 million people, over 3 million have diabetes (6.4%). In 2010 year 106 billion was spent on healthcare for diabetes in the EU. Exercise is a key component to good diabetes management as well as helping people to avoid diabetes altogether by improving body's use of insulin, burning body fat, helping to decrease and control weight, increasing muscle strength, increasing bone density and strength. Walking, aerobic, strength training, stretching, swimming are highly recommended activities to people with Type 2 Diabetes. A 250-300 minutes frequency of physical activity (PA) per week can be very helpful in controlling this pathological state. Pilates is a controlled exercise program that can be used to achieve fitness and health goals. It is convenient and inexpensive. Pilates can be done at home, learning techniques from TV or a DVD. Also, Pilates is free of risk for people with Type 2 diabetes which is a vulnerable category because of altered lower limb biomechanics and possible gait dysfunction. Las estadísticas muestran que 285 millones de personas sufren de Diabetes Tipo II, esto es el 6% de la población mundial adulta y 60 millones de personas en los Estados Unidos (10% de la población). De los 47 millones de habitantes que posee España, mas de 3 millones de personas sufren de diabetes (6.4%). En el año 2010 se gastaron más de 106 mil millones de dólares en salud por causa de la diabetes en los Estados Unidos. El ejercicio físico es una manera de evitar la diabetes en la población a través de: un mejor  uso de la propia insulina producida por el cuerpo, de la quema de grasas, del control del peso corporal, del aumento de la fuerza muscular y del aumento en la densidad y calidad ósea. Una frecuencia semanal de 250 a 300 minutos de actividad física puede resultar de gran ayuda en el control de esta patología. La práctica de Pilates es un ejercicio que puede ser utilizado para lograr fácilmente un estado físico saludable. Puede ser realizado en el hogar, aprendiendo la técnica a través de la TV o de DVDs, es conveniente y sin costos. Además no presenta riesgos para las personas con diabetes tipo II, quienes son vulnerables por presentar una biomecánica disminuida en los miembros inferiores y/o una disfunción de la marcha.

Impact of stochastic representations of pedestrian actions on serviceability response

Over the past 15 years, there have been some research outcomes in other disciplines that could be used to produce new, more accurate and realistic numerical models to characterise pedestrian loads and to significantly improve predictions of response for multiple-pedestrian scenarios. However, the disconnection between fields has not facilitated this further research. Using this, the paper presents (a) a new sophisticated load model that includes a description of vertical and lateral loads, including pedestrian–structure interaction, (b) the numerical description of relationships to describe the key parameters of the proposed model and (c) the evaluation of the effects of pedestrian characteristics that are relevant for serviceability response of footbridges. The proposed new load model allows for the inherent variability of individual pedestrian actions (intra-subject variability), a probabilistic description of how pedestrian characteristics vary among subjects (inter-subject variability) and collective human behaviour (pedestrian–pedestrian interaction). Some of these characteristics are not currently considered in design approaches and can have a substantial impact on structural response assessments. Finally, recommendations are made for many of these characteristics to be introduced in analyses to evaluate the vibration serviceability limit state of footbridges in a more accurate and realistic manner

Motivating Emotional Intelligence: A Reinforcement Sensitivity Theory (RST) Perspective

Trait emotional intelligence (trait EI) is generally associated with positive outcomes and can inform clinical and social interventions. We investigated the sub-factors of trait EI: Wellbeing, Self-control, Emotionality, and Sociability, in the context of the Reinforcement Sensitivity Theory (RST) of motivation. In Study 1, participants (N = 247) completed Carver and White’s (1994) BIS/BAS scales and a measure of trait EI. All EI sub-factors were positively associated with BAS Drive and negatively with BIS. Study 2 (N = 382) employed a new questionnaire based on revised RST (Corr & Cooper, 2016). All trait EI factors were positively associated with BAS Goal-Drive Persistence and Reward Interest, and negatively with the BIS. Self-control showed negative associations with BAS Impulsivity and was the only factor not to correlate with BAS Reward Reactivity. Results suggest that high trait EI individuals are goal driven, sensitive to reward and lower in avoidance motivation and negative emotion. This motivational basis to trait EI further explicates its structure

Relocation and investment in R&D by firms

The literature on foreign direct investment has analyzed corporate location decisions when firms invest in R&D to reduce production costs. Such firms may set up new plants in other developed countries while maintaining their domestic plants. In contrast, we here consider firms that close down their domestic operations and relocate to countries where wage costs are lower. Thus, we assume that firms may reduce their production costs by investing in R&D and likewise by moving their plants abroad. We show that these two mechanisms are complementary. When a firm relocates it invests more in R&D than when it does not change its location and, therefore, its production cost is lower in the first case. As a result, investment in R&D encourages firms to relocate.info:eu-repo/semantics/publishedVersio

Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador

Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era. Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact characteristics). Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission. Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees