Search results
Results from the WOW.Com Content Network
For whatever power level the reactor is currently operating at, a certain amount of enthalpy is present in the coolant. This enthalpy is proportional to temperature, therefore, the hotter the plant, the higher the pressure must be maintained to prevent boiling. When pressure drops to the saturation point, dryout in the coolant channels will occur.
The Fukushima Daiichi nuclear disaster in 2011 occurred due to a loss-of-coolant accident. The circuits that provided electrical power to the coolant pumps failed causing a loss-of-core-cooling that was critical for the removal of residual decay heat which is produced even after active reactors are shut down and nuclear fission has ceased.
At a cellular level, shock is the process of oxygen demand becoming greater than oxygen supply. [6] One of the key dangers of shock is that it progresses by a positive feedback loop. Poor blood supply leads to cellular damage, which results in an inflammatory response to increase blood flow to the affected area.
Pulmonary embolism is blood clots occurring in the lungs. Restricted blood flow in the pulmonary circulation results in alveoli ventilated but not perfused, thus, increasing the V/Q ratio and decreasing gas exchange. It can cause hypoxemia(low oxygen level) and damage part of the lung, which may be treated with anticoagulants.
Vascular resistance is the resistance that must be overcome for blood to flow through the circulatory system.The resistance offered by the systemic circulation is known as the systemic vascular resistance or may sometimes be called by another term total peripheral resistance, while the resistance caused by the pulmonary circulation is known as the pulmonary vascular resistance.
Blood resistance varies depending on blood viscosity and its plugged flow (or sheath flow since they are complementary across the vessel section) size as well, and on the size of the vessels. Assuming steady, laminar flow in the vessel, the blood vessels behavior is similar to that of a pipe.
In the arterial system, bubbles (arterial gas embolism) are far more dangerous because they block circulation and cause infarction (tissue death, due to local loss of blood flow). In the brain, infarction results in stroke , and in the spinal cord it may result in paralysis .
This can include low partial pressures of oxygen in the breathing gas, problems with diffusion of oxygen in the lungs through the interface between air and blood, insufficient available hemoglobin, problems with blood flow to the end user tissue, problems with the breathing cycle regarding rate and volume, and physiological and mechanical dead ...