Transmission efficiency, definition

In general, a UV-Vis transmission experiment offers the fastest and most direct method of estimating the optical bulk band gap and should be a priority for any newly synthesized material. A diffuse reflectance or absorption configuration can be used if the sample is not transmissive. If a diffuse reflectance experiment is not available, then photocurrent spectroscopy (as described in Chapter Efficiency definitions in the field of PEC ) with extremely facile redox couples can be performed, though errors in this method may arise from poor charge carrier mobilities or lifetimes and from slow kinetics at the sample-electrolyte interface. 

Magnetic sector instruments are still used in trace analysis of analytes (generally of environmental concern) that are sufficiently stable that they are amenable to GC separation followed by ionization by El or Cl. Double focusing instruments provide an unmatched combination of high transmission efficiency at high resolving power, up to 10% transmission at a resolving power of 10000 (on the 10 % valley criterion, equivalent to 20 000 on the EWHM definition of RP, Section 6.2.3b). Coupled with excellent duty cycle in SIM mode, this has led to their continued use (Section 11.4) in difficult analyses, e.g.. 

The resolution achievable by a quadrupole filter depends on several factors including the selection of the U/Vq ratio and can thus be adjusted. In practice the resolution is held at the lowest acceptable level to promote as high an ion-transmission efficiency as possible. At the present time commercial quadrupole mass spectrometers are limited with few exceptions to resolutions of 1000 or less (10 per cent valley definition). 

Nonadiabatic transitions definitely play crucial roles for molecules to manifest various functions. The theory of nonadiabatic transition is very helpful not only to comprehend the mechanisms, but also to design new molecular functions and enhance their efficiencies. The photochromism that is expected to be applicable to molecular switches and memories is a good example [130]. Photoisomerization of retinal is well known to be a basic mechanism of vision. In these processes, the NT type of nonadiabatic transitions play essential roles. There must be many other similar examples. Utilization of the complete reflection phenomenon can also be another candidate, as discussed in Section V.C. In this section, the following two examples are cosidered (1) photochromism due to photoisomerization between cyclohexadiene (CHD) and hexatriene (HT) as an example of photoswitching molecular functions, and (2) hydrogen transmission through a five-membered carbon ring. 

According to the above definition, sensitivity does not only depend on the ionization efficiency of El or any other ionization method. Also relevant are the extraction of ions from the ion source, the mass range acquired during the experiment, and the transmission of the mass analyzer. Therefore, the complete experimental conditions have to be stated with sensitivity data. 

In order to optimise individual structures in the lO-design the definition of parameter-loops and scanning routines is required. In combination with this, post-processing of BPM-runs to evaluate channel-specific mode amplitudes, system transmission etc. is necessary, as well, which is assisted by eommercial lO-design tools, naturally. This facilitates the generation of parametric models for any optical sub-system, cf. figures 11 and 12, which at the end is a prerequisite for an efficient system design. 

The terms, electromechanical coupling factor, energy transmission coefficient, and efficiency are sometimes confused (5. All are related to the conversion rate between electrical energy and mechanical energy, but their definitions are different [6]. 

---