2,423 research outputs found

    Fire spread experiment across Mediterranean shrub: Influence of wind on flame front properties

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    International audienceA previous termfirenext term spread experiment was conducted in the field under wind-blown conditions. The fuel consists of tall and dense Mediterranean shrub vegetation. The plot area was about 30 m wide and 80 m long. This experiment was conducted not only in order to increase the knowledge and understanding of the previous termfirenext term behaviour in the field but to provide data for the validation of physics based models of previous termfirenext term spread. In particular, the effects of wind on the geometric and thermal properties of the flame front in the field were investigated. The flame temperature along the vertical direction and the radiation emitted ahead of the flame front, were measured. The methodology employed in this experiment and some quantitative measurements of wind velocity and direction, flame geometric properties, are also presented and discussed. The measurements and observations exhibit that the behaviour of the previous termfirenext term and the flame structure character are very different from the one encountered at laboratory scale. These preliminary results show that large scale turbulence influence previous termfirenext term spread and affects the flame shape, temperature and radiation emission

    Federico di Montefeltro's hyperkyphosis: a visual-historical case report

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    <p>Abstract</p> <p>Introduction</p> <p>The literature contains several publications describing the use of visual arts to develop observational skills in medical students. Portraits of individuals of the Italian Renaissance can be used to enhance these skills and stimulate the development of differential diagnoses in medical students. The Duke of Urbino, Federico di Montefeltro (1422–1482), lost his right eye and nasal bridge during a jousting accident in 1450. Consequently, almost every profile of him in existence today depicts his face in a left lateral view. Although some authors have described the Duke's missing nasal bridge, none have described his prominent thoracic hyperkyphosis, which is clearly discernible in two paintings by Piero della Francesca. The purpose of this report is to describe the Duke's hyperkyphosis, develop relevant differential diagnoses, and suggest a possible etiology of the convexity.</p> <p>Case presentation</p> <p>We have examined two paintings of the Duke by Piero della Francesca – the diptych, <it>The Duke and Duchess of Urbino </it>(1465), and the <it>Madonna of the Egg </it>(1472). A MEDLINE search revealed 2 articles that were relevant to this study. This search was complemented by a search of the collection at the library of Seton Hall University, and the first author's experience studying at the University of Urbino. The historical data obtained from these searches were incorporated with the visual analysis to formulate a plausible etiology of the Duke's thoracic hyperkyphosis.</p> <p>Conclusion</p> <p>Differential diagnoses of the Duke's thoracic hyperkyphosis include Scheuermann disease, osteoporosis, and trauma-related spinal changes. Based on the available evidence, the Duke's thoracic hyperkyphosis could have been caused by repetitive trauma to the spine due to numerous hours on horseback with heavy armor. The role that osteoporosis played in the development of the hyperkyphosis is unclear, as is whether the Duke had the convexity during childhood. The hyperkyphosis as a stylistic variant by Piero della Francesca is unlikely. This report is an example of a teaching strategy that can be used to enhance the observational skills of medical students in evidence-based medical education.</p
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