Abstract: An assembly for producing a weld coupling a first part of a workpiece to a second part of the workpiece. The assembly comprises a first incoherent light source that generates incoherent light energy and a first negative waveguide having an input end and an output end, the incoherent light energy from the first incoherent light source and that reflected by the first reflector entering the first negative waveguide at the input end, passing through the first negative waveguide and exiting the first negative waveguide at the output end.

Abstract: The basal metabolic rate (BMR) of a human subject is measured with the subject reclining in a non-adiabatic whole-body calorimeter. Heat losses which occur through the uninsulated wall of the calorimeter chamber during the measurement period are determined in a preliminary calibration step, in the absence of the subject. The BMR measurement is simply made, requiring only the determination of the ambient air and the calorimeter chamber inlet air temperatures, the change of outlet air temperature with time (open circuit), air flow rate, and relative humidity. The use of insulation, sensors in the calorimeter wall and of a circulating water stream to measure temperature increase are unnecessary.