Ratios between emission channels

This detector responds to infrared emissions in at least two wavelengths. Typically a CO2 reference at 4.45 microns is established and a second reference channel that is away from the CO2 and H2O wavelengths is made. It requires that the two signals received are confirmed as are synchronous and that the ratio between both signals is correct. 

Figure 1 Determination of optimal ludferase quantity and background BRET. Luciferase titrations are plotted as a function of the amount of transfected energy donor DNA, in the absence of energy acceptor (fluorescent protein). The resulting BRET ratio (black circles) is plotted on the left Y axis, and the luminescence counts (white circles) are plotted on the right Y axis. The detected BRET ratio decreases to reach a background value that is stable over increasing luminescence, and that must be deduced from experimental BRET ratios to obtain BRETnet- This instrument-dependent stable background BRET is due to bleeding of the donor emission into the acceptor emission channel (note the scale difference between the BRET and BRET systems). The higher BRET ratios at too low luminescence counts are due to noise detection in the acceptor emission channel.

Table III. Some Average Product Translational Energies, Reactive Cross Sections and the Ratios between CH, Emission and H Emission Channels (34, 35). 

There are two ways to determine the G factor [308, 389]. The first one is to ran a measurement with horizontal polarisation of the excitation beam. For an angle of 90° between the optical axis of excitation and emission, the excited-state distribution is oriented towards the axis of observation. Consequently both channels measure equal perpendicular components. The ratio of the measured intensities represents the G factor. 

In catalytic channels, the flat plate surface temperature in Eq. (3.32) is attained at the channel entry (x O). As the catalytic channel is not amenable to analytical solutions, simulations are provided next for the channel geometry shown in Fig. 3.3. A planar channel is considered in Fig. 3.3, with a length L = 75 mm, height 21) = 1.2 mm, and a wall thickness 5s = 50 pm. A 2D steady model for the gas and solid (described in Section 3.3) is used. The sohd thermal conductivity is k = 6W/m/K referring to FeCr alloy, a common material for catalytic honeycomb reactors in power generation (Carroni et al., 2003). Surface radiation heat transfer was accounted for, with an emissivity = 0.6 for each discretized catalytic surface element, while the inlet and outlet sections were treated as black bodies ( = 1.0). To illustrate differences between the surface temperatures of fuel-lean and fuel-rich hydrogen/air catalytic combustion, computed axial temperature profiles at the gas—wall interface y=h in Fig. 3.3) are shown in Fig. 3.4 for a lean (cp = 0.3) and a rich cp = 6.9) equivalence ratio, p = 1 bar, inlet temperature, and velocity Tj = 300 K and Uin = 10 m/s, respectively. The two selected equivalence ratios have the same adiabatic equilibrium temperature, T d=1189 K. 

---