A ton of refrigeration (TR), also called a refrigeration ton (RT), is a unit of power used in some countries (especially in North America) to describe the heat-extraction capacity of refrigeration and air conditioning equipment.
A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. In most cases, a brain aneurysm causes no symptoms and goes unnoticed. In rare cases, the brain aneurysm ruptures, releasing blood into the skull and causing a stroke. High blood pressure. 2  The risk of subarachnoid hemorrhage is greater in people who have a history of high blood pressure. 3  Smoking. 4  In addition to being a cause of high blood pressure, the use of cigarettes may greatly increase the chances of a brain aneurysm rupturing.
Unruptured brain aneurysm. Overview. An aneurysm is a balloon-like bulge of an artery wall. As an aneurysm grows it puts pressure on nearby structures and may eventually rupture. Most people find out they have an unruptured aneurysm by chance during a scan for some other problem. The risk of rupture varies depending on the aneurysm location and size.