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.
energy expenditure using doubly labelled water Iso-Analytical provides a full range of analytical services for customers wishing to determine Energy Expenditure using doubly labelled water. The Doubly Labelled Water (DLW) method uses the natural occurring stable isotopes of water (D 2 O and H 2 18 O) to assess energy expenditure, body composition and water flux in humans and animals. The DLW method is entirely safe and non-restrictive, requires only periodic sampling of body fluids and is well suited for measurement of energy expenditure in free-living or hospitalized patients.