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.
A steel I-beam is a type of joist or girder made from structural steel. I-beams are used as major support trusses in building, to ensure that a structure will be physically sound. Steel is one of the most common materials used to make I-beams, since it can withstand very heavy loads, although other materials, such as aluminum, are sometimes used. Composite I-beams are also available, with layers of other materials encasing the outside of the steel to disguise it as something else, such as wood.