8,459 research outputs found
Sport and maximisation of the subjective perception of wellbeing: A trend analysis of sporting practises at the start of the 21st century.
We have seen a transformation in the development of sporting activities over recent decades. There are a number of social factors behind this. In this article, we report a longitudinal study of sporting activities in Spain between 1995 and 2014 among the population aged 18 and over, including both sexes, examining the social relationships that arise in sporting activities. Our analysis is based on national databases and analysis of trends in sporting activities. It demonstrates the main hypothesis of the study, which is that individual sporting activities have increased compared to group activities with family and friends. We also examine changes in sporting activities depending on the primary relations established in the sport, by sex, age, habitat, occupation, educational level, the form in which the sport is practised, the degree of competition, frequency, the sports facilities used, the type of sport, hours of free time and the subjective sensation of happiness
Effects of a Peer-To-Peer Mentoring Program: Supporting First-Year College Students’ Academic and Social Integration on Campus
This paper presents findings from a peer-to-peer mentoring program supporting ethnically diverse first-generation students at a mid-sized university in the Southwest. Research on mentoring during the undergraduate years has placed emphasis on the quality of lived-collegiate experiences from both a peer-mentor and mentee perspective (Crisp, Baker, Griffen, Lusnford, & Pifer, 2017). Using a mixed methods approach, two survey instruments and qualitative analysis, interviews with peer-mentors and mentees suggested student development occurred through various means: (i) academics, (ii) university involvement, and (iii) the reinforcement of friendship. These findings reinforce theory first drawn from Tinto’s (1993) student integration perspectives (e.g., academic and social integration). Peer-mentors fulfilled their roles, while mentees who were actively involved in the program reported to have benefitted the most. The effectiveness of the mentoring program highlighted contributions to enhancing, at least one of the following, for all mentees: first-year experience, degree of college involvement, and overall retention rate
Open-source digital technologies for low-cost monitoring of historical constructions
This paper shows new possibilities of using novel, open-source, low-cost platforms for the structural health monitoring of heritage structures. The objective of the study is to present an assessment of increasingly available open-source digital modeling and fabrication technologies in order to identify the suitable counterparts of the typical components of a continuous static monitoring system for a historical construction. The results of the research include a simple case-study, which is presented with low-cost, open-source, calibrated components, as well as an assessment of different alternatives for deploying basic structural health monitoring arrangements. The results of the research show the great potential of these existing technologies that may help to promote a widespread and cost-efficient monitoring of the built cultural heritage. Such scenario may contribute to the onset of commonplace digital records of historical constructions in an open-source, versatile and reliable fashion.Peer ReviewedPostprint (author's final draft
Web crippling strength of longitudinally stiffened steel plate girder webs subjected to concentrated loading
Currently, the AISC code provides guidance for the calculation of the ultimate strength of unstiffened plate girder webs subjected to concentric edge loads. Specifications consider three categories: local web yielding, web crippling, and sideway web buckling. Based on previous studies, the presence of longitudinal stiffeners in the web has not been considered in the calculation procedures. Longitudinal stiffeners in steel plate girders are primarily used to increase bending and shear strength. In the last two decades, a number of projects regarding the positive effect of longitudinal stiffening on the strength of plate girder webs to concentrated load have been conducted around the world. The results have shown that this type of stiffening enhances ultimate strength for web crippling depending on the position of the stiffener that modifies the slenderness of the directly loaded panel; and flexural and torsional rigidities of the stiffener. This paper presents a methodology for the consideration of longitudinal stiffening on the ultimate strength of plate girders webs subjected to concentrated loads. The methodology is based on the plastic collapse mechanism observed experimentally, in which plastic hinges are formed in the loaded flange and yield lines result in the portion of the web limited by the loaded flange and stiffener. Then, a closed-form solution accounting for the influence of the stiffener is developed following the current expression available in the AISC specifications. Theoretical predictions are compared with available test results, showing that the predicted ultimate loads are in good agreement with experimental results.Postprint (published version
Designing experiments using digital fabrication in structural dynamics
In engineering, traditional approaches aimed at teaching concepts of dynamics to engineering students include the study of a dense yet sequential theoretical development of proofs and exercises. Structural dynamics are seldom taught experimentally in laboratories since these facilities should be provided with expensive equipment such as wave generators, data-acquisition systems, and heavily wired deployments with sensors. In this paper, the design of an experimental experience in the classroom based upon digital fabrication and modeling tools related to structural dynamics is presented. In particular, all experimental deployments are conceived with low-cost, open-source equipment. The hardware includes Arduino-based open-source electronics whereas the software is based upon object-oriented open-source codes for the development of physical simulations. The set of experiments and the physical simulations are reproducible and scalable in classroom-based environments.Peer ReviewedPostprint (author's final draft
Modeling the AC Electrokinetic Behavior of Semiconducting Spheres
We study theoretically the dielectrophoresis and electrorotation of a semiconducting microsphere immersed in an aqueous electrolyte. To this end, the particle polarizability is calculated from first principles for arbitrary thickness of the Debye layers in liquid and semiconductor. We show that the polarizability dispersion arises from the combination of two relaxation interfacial phenomena: charging of the electrical double layer and the Maxwell–Wagner relaxation. We also calculate the particle polarizability in the limit of thin electrical double layers, which greatly simplifies the analytical calculations. Finally, we show the model predictions for two relevant materials (ZnO and doped silicon) and discuss the limits of validity of the thin double layer approximation
Dipolophoresis and Travelling-Wave Dipolophoresis of Metal Microparticles
We study theoretically and numerically the electrokinetic behavior of metal microparticles immersed in aqueous electrolytes. We consider small particles subjected to non-homogeneous ac electric fields and we describe their motion as arising from the combination of electrical forces (dielectrophoresis) and the electroosmotic flows on the particle surface (induced-charge electrophoresis). The net particle motion is known as dipolophoresis. We also study the particle motion induced by travelling electric fields. We find analytical expressions for the dielectrophoresis and induced-charge electrophoresis of metal spheres and we compare them with numerical solutions. This validates our numerical method, which we also use to study the dipolophoresis of metal cylinders.Spanish Research Agency MCI under contract PGC2018-099217-B-I00
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