Scalp sensitivity has several origins. It could be caused by an imbalance in the sebum secretion process, which leads to irritation. Pollution and stress can also irritate the scalp. In fact, pollution coats the hair in harmful elements that create a dull film over the hair and, like stress, generate free radicals.
Hard drive sizes. Hard drives come in two basic physical sizes: 2.5-inch and 3.5-inch. These sizes refer to the size of the data platters, not the size of the hard drive mechanism. Traditionally, 2.5-inch drives are used for laptops while 3.5-inch drives are used for desktop computers. Some compact desktops also use the smaller drives to enable a smaller form factor for the computer.
Floppy disk drives have a drive motor, stepper motor, read/write heads, a mechanical frame, and a circuit board. A floppy disk, also called a diskette, is a 3.5 inch thin square piece of plastic that has the capacity of 1.44 megabytes. The floppy disk also has tracks and sectors. Function. A floppy disk drive reads/writes data onto a small circular piece of metal-coated plastic.