In the Hornbostel-Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a shell and struck, either directly with the player's hands, or with a drum stick, to produce sound.
Heat production can be calculated from a measurement of VO 2 and/or CO 2. Doubly-Labeled Water Doubly-labeled water contains isotopes of oxygen and of hydrogen. The technique involves the consumption by the patient of the doubly-labeled water then the measurement of the amount of isotope in the person after a washout period of 7- 14 days. Most of the hydrogen and oxygen isotopes are lost through excretion and evaporation, but some of the oxygen isotope equilibrates with carbon dioxide and is expired in air.
The only way to know whether your tap water contains lead is to have it tested. You cannot see, taste, or smell lead in drinking water. Therefore, you must ask your water provider whether your water has lead in it. For homes served by public water systems, data on lead in tap water may be available on the Internet from your local water authority. If your water provider does not post this information, you should call and find out.