You may not think of salt and sugar as solids because when you see them in the kitchen they are such small particles. But each of these particles is as much a solid as a wooden table, a glass window, or a gold piece of jewelry. A solid is a collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and size.
Pulse Width Modulation, or PWM, is a technique for getting analog results with digital means. Digital control is used to create a square wave, a signal switched between on and off.
Low molecular weight heparin. Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention blood clots and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism) and in the treatment of myocardial infarction.