An electrical contact is an electrical circuit component found in electrical switches, relays and breakers. It is composed of two pieces of electrically conductive metal that pass electrical current or insulate when the gap between them is closed or open.
noun. Schwa is a vowel sound in an unstressed syllable, or the phonetic symbol É which is the International Phonetic Alphabet symbol for schwa. An unstressed syllable in a word, such as the a syllable in ago, is an example of schwa.oun. 1  A mid-central neutral vowel, typically occurring in unstressed syllables, as the final vowel of English sofa. 2  The symbol (&schwa;) used to represent an unstressed neutral vowel and, in some systems of phonetic transcription, a stressed mid-central vowel, as in but.
Crackles are the sounds you will hear in a lung field that has fluid in the small airways. As stated before, crackles and rales are the same thing, and this can often lead to confusion among health care providers. Crackles come in two flavours: fine and coarse. Fine crackles sound like salt heated on a frying pan or the sound of rolling your hair between your fingers next to your ear. Coarse crackles sound like pouring water out of a bottle or like ripping open Velcro. This lung sound is often a sign of adult respiratory distress syndrome, early congestive heart failure, asthma, and pulmonary oedema. Rhonchi, rales, wheezes, rubbing or stridor? â Listening for lung sounds.