Ex nihilo is a Latin phrase meaning out of nothing,â which often appears in conjunction with the concept of creation, as in creatio ex nihilo, meaning creation out of nothing.â Not only do scientists think the Universe was created out of nothing, or that nothing existed before the singularity, but even Creationists, those who believe God created ...
There are two main categories of diaphragm valves: one type seals over a weir (saddle) and the other (sometimes called a full bore or straight-way valve) seals over a seat.
The diaphragm is dome-shaped. The middle part of this dome is depressed just where the heart and its compartment, the mediastinum, are located. This makes the diaphragm a double dome, one on either side. It is the middle of these two side domes that move during respiration (breathing).