The lungs move air in and out like bellows. Fresh, oxygen-rich air mixes with intrapulmonary air. Oxygen is carried with the circulation and carbon dioxide is excreted with the exhaled air. Various mechanisms maintain the purposeful distribution of ventilation and circulation. Very much of the complicated physiology and pathophysiology is already known, and it has recently become possible to ob...

CONTEXT Yoga is an ancient science, which originated in India. Pranayama has been assigned a very important role in yogic system of exercises. It is known that regular practice of breathing exercises (pranayama) increases parasympathetic tone, decreases sympathetic activity, and improves cardiovascular functions. Different types of breathing exercises alter autonomic balance for good by either ...

The term "contact aging" refers to the temporal evolution of the interface between a slider and a substrate usually resulting in increasing friction with time. Current phenomenological models for multiasperity contacts anticipate that such aging is not only the driving force behind the transition from static to sliding friction, but at the same time influences the general dynamics of the slidin...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We give an example of a geometry in which the electrostatic force between a point charge and a neutral metallic object is repulsive. The example consists of a point charge centered above a thin metallic hemisphere, positioned concave up. We show that this geometry has a repulsi...

‘In some of my tests I have noticed the effects and deflection of these waves by metallic objects miles away. It seems to me that it should be possible to design apparatus by means of which a ship could radiate or project a divergent beam of these rays in any desired direction, which rays, if coming across a metallic object, such as another steamer or ship, would be reflected back to a receiver...