Collapse, sudden

When only slit A is open, the particle emitted by the source S passes through slit A, thereby causing the wave function ft (x) in equation (1.48) to change or collapse suddenly to ft A( )- The probability density 7a(x) that the particle strikes point x on the detection screen is, then... 

VF is electrical anarchy of the ventricle resulting in no cardiac output and cardiovascular collapse. Sudden cardiac death occurs most commonly in patients with ischemic heart disease and primary myocardial disease associated with LV dysfunction. VF associated with acute MI may be classified as either (1) primary (an uncomplicated MI not associated with heart failure [HF]) or (2) secondary or complicated (an MI complicated by HF). 

In June 2001, a government advisory panel convened by the FDA concluded that GHB could be useful as a treatment for cataplexy, a rare but dangerous complication of the sleep disorder narcolepsy. This panel was asked to consider whether prescription sales should be permitted for GHB under the brand name Xyrem . The committee concluded that the manufacturer of the drug (Orphan Medical) had shown that Xyrem is useful in treating cataplexy, a complication that can cause people to collapse suddenly when their muscles lose strength. 

Vigorous diuresis may lead to profound water loss and electrolyte depletion, resulting in hypokalemia, hyponatremia, dehydration. Sudden volume depletion may result in increased risk of thrombosis, circulatory collapse, sudden death. Acute hypotensive episodes may also occur, sometimes several days after beginning therapy. 

In some cases, the gravitational attraction between molecules in a cloud is strong enough in and of itself to cause the cloud to begin collapsing onto itself. In other cases, some external event may initiate or accelerate that collapse. For example, the explosion of a neighboring star can produce a shock wave of sufficient intensity to force a molecular cloud to collapse suddenly. Also, two clouds may collide with each other, causing contraction of them both. 

Erythromycin. An 87-year-old woman collapsed suddenly in her kitchen 4 days after starting to take astemizole 10 mg daily and erythromycin twice daily [dose unknown]. An ECG showed her to be having multiple episodes of torsade de pointes arrhythmias, the longest of which lasted 17 seconds. Her QTc was 720 milliseconds and she was mildly hypoka-laemic. She was given a temporary pacemaker and when she was eventually discharged with a normal sinus rhythm, her QTc had fallen to 475 milliseconds. ... 

This is exactly the phenomenon called the collapse of polymer networks. It was discovered by T. Tanaka (1946-2000) and his colleagues at the Massachusetts Institute of Technology (MIT) in 1978. They used networks of polyacrylamide diluted in a mixture of acetone and water. In these experiments, the temperature was not varied. To make the solvent worse, they just poured some extra acetone into the solution. (This worked because acetone, in contrast to water, is a bad solvent for polyacrylamide.) Figure C9.7 gives an idea of what was found. It sketches how the size of the network depends on the acetone concentration. You can see that if you dump 42% of acetone, the network collapses suddenly. Its volume drops by a factor of nearly 20. 

In June 1958, two spans of a six lane highway bridge under construction across the Burrard Inlet in the Greater Vancouver area, Canada, collapsed suddenly. 

It was found from the failure pattern that the unreinforced slope was prone to collapse suddenly, while reinforced slopes were able to maintain their integrities. As far as the reinforced slope is concerned, cracks mainly occurred in three places (1) the zone near the surface, from toe to half of the slope (2) top of the slope and (3) the interface between each layer of reinforcement and the soil. The cracks occurred first near the slope surface. The cracks on top of the slope were mainly tension cracks. The largest crack on the top mainly located in the unreinforced region. In the reinforced... 

Cavitation can also lead to local destruction of protective layers. In rapidly flowing liquid and on solid surfaces that oscillate in the liquids, gas or steam bubbles are produced at sites at which the pressure in the liquid is briefly lowered to vapor pressure due to flow in excess of the critical flow rate threshold. When the pressure is raised again, these bubbles collapse suddenly (implosion) and a jet of liquid hits the material surface at a high rate of speed. This sudden stress load pattern is continuously exposing or creating active surfaces on which increased corrosion (cavitation corrosion) takes place in an aggressive medium. 

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