Dialysis blocks the passage of larger substances (for example, red blood cells, large proteins). This replicates the filtering process that takes place in the kidneys when the blood enters the kidneys and the larger substances are separated from the smaller ones in the glomerulus. The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite.
Pipe organ pressures are on the order of . Organ builders often measure organ wind using a U-tube manometer containing water, so commonly give its magnitude as the difference in water levels in the two legs of the manometer, rather than in units of pressure. The difference in water level is proportional to the difference in pressure between the wind being measured and the atmosphere. The 0.10 psi above would register as 2.75 inches of water (70 mmAq). An Italian organ from the Renaissance period may be on only , while (in the extreme) solo stops in some large 20th-century organs may