Heat Loss Compensated Calorimeter

Heat loss from humans measured with a direct calorimeter and heat-flow meters.

1. Heat loss from three men and three women was measured in a direct calorimeter over 2 or 3 h periods and compared with that determined simultaneously from heat-flow meters attached to the skin surface at the waist. The comparisons were made at each of four ambient temperatures, 15, 20, 25 and 30 degrees. Each subject wore a cotton boiler-suit and minimal underwear. 2. Oral temperatures and sk...

Loss-compensated and active hyperbolic metamaterials.

We have studied the dispersion relations of multilayers of silver and a dye-doped dielectric using four methods: standard effective-medium theory (EMT), nonlocal-effect-corrected EMT, nonlinear equations based on the eigenmode method, and a spatial harmonic analysis method. We compare the validity of these methods and show that metallic losses can be greatly compensated by saturated gain. Two r...

Cone Calorimeter – a Tool for Measuring Heat Release Rate

The cone calorimeter is considered the most significant bench scale instrument in fire testing. This apparatus has been adopted by the International Organization for Standardization (ISO 5660-1) for measuring heat release rate (HRR) of a sample. It has been shown that most fuels generate approximately 13.1 MJ of energy per kg of oxygen consumed. Therefore, HRR is based on the fact that the oxyg...

Studies of Excess Heat and Convection in a Water Calorimeter

To explain a difference of 0.5 % between the absorbed-dose standards of the National Institute of Standards and Technology (NIST) and the National Research Council of Canada (NRCC), Seuntjens et al. suggest the fault lies with the NIST water calorimeter being operated at 22 °C and the method with which the measurements were made. Their calculations show that this difference is due to overpredic...

On the Determination of Specific Heat and of Latent Heat of Vaporization with the Vapor Calorimeter