Stridor is a sign of upper airway obstruction. In children, laryngomalacia is the most common cause of chronic stridor, while croup is the most common cause of acute stridor.Generally, an inspiratory stridor suggests airway obstruction above the glottis while an expiratory stridor is indicative of obstruction in the lower trachea. laryngeal web, cyst or laryngocele may present with stridor, usually at birth or soon after. Laryngotracheobronchitis (Viral Croup) . The most common cause of acute stridor in childhood is laryngotracheobronchitis, or viral croup.
The load in the floor beam is then transferred to the main load carrying system, such as a longitudinal plate girder. Per Article 9.8.3.1 of the AASHTO LRFD (5 th Edition, 2010), the deck plate is to act as a common flange of the ribs, the floor beams, and the main longitudinal components of the bridge.
In engineering calculations, the span of a beam (a truss is a beam) is squared. This means a 30 foot span is 50% wider than a 20 foot span, but must have 225% of the load carrying capacity! The load carrying capacity is handled by larger or higher graded material being used for the truss top and bottom chords, as well as the webs. Roof truss plates, the pressed in steel connectors, also get larger.