Probe system, factors influencing

Besides the impressive difference in the chemiexcitation efficiency, also the fluorescence yield of the meta-pattemed emitter m-17 is by more than an order of magnitude ( ) higher than that of the para regioisomer p-17 . Evidently, crossed-conjugated emitters are advantageous for the design of efficient intramolecular CIEEL systems. In Sections V.A-V.C we shall consider additional internal (substrate structural effects) and external (medium influence) factors, which play an essential role in the development of efficient dioxetane-based analytical probes. 

A simple method for determining the temperature inside the sample volume of an NMR probe is the quantitative evaluation of the absolute intensity using Curie s law (Eq. (25)). However, this approach is limited to systems that heat the sample volume only and not the radio frequency coil or other electronic parts of the probe. A heating of the radio frequency coil strongly influences the quality factor of the NMR probe and leads to an additional change of the signal intensity and, therefore, renders the quantification of intensity more complicated. 

In particle probe analysis systems, x-rays are generated from the elements due to an excitation caused by the impinging particles, whether they are electrons or protons, and these secondary x-rays are emitted in all directions. However, the detector can only cover a small part of the sphere of secondary radiation (Figure 5.3), even if the geometry of the experimental setup allows the detector to come very close to the object, which will increase the spatial angle from which the detector sees the volume of analysis. Here we see a factor which influences markedly the sensitivity of the analysis method. 

Noise measurements are extensively used in the studies of metastable pits. Pistorius37 discussed several factors that can influence the proper interpretation of electrochemical noise measurements (ENM). These factors can be probe size, sampling rate, and system noise. The current measurements seem to give clearer information on the corroding system than that of the potential28 46... 

In view of this fit, and of the fact that Rodger et al. used an impeller type that is in common use, Eq. (34) seems to be preferable for engineering estimates. However, the strong effects of variations in impeller design or system geometry which were not studied, and the possible influence of the relatively large probe on the flow, and the absence of measurements at other volume fractions or with other continuous phases, all must be considered as factors which indicate the need of caution in any application of Eq. (34). 

NMR spectroscopy probes transitions between nuclear spin states. The transition frequencies and relaxation times contain a wealth of information related to molecular structure and dynamics. Transition frequencies also reveal couplings between nuclear spins, and between electron and nuclear spins. The primary experimental observables in NMR are the chemical shift, which is related to the transition frequency, and the line width, which is related to the relaxation time. In paramagnetic systems, both of these parameters have the potential to be affected significantly by the unpaired electron, requiring special interpretation of data but also revealing information on the nature of the metal site. To make full use of NMR to study complex systems such as metallobiomolecules, it is important to understand the factors that influence observables in NMR. 

Diffusion of Water Vapor in Newborn Rat Stratum Corneum. Measurement and interpretation of diffusion in heterogenous biological systems such as the stratum corneum are difficult compared with similar measurements for well-defined synthetic polymer systems, but studies of water diflFusion in stratum corneum are essential to a better understanding of those factors which contribute to the barrier function of the corneum. Water diffusion measurements under both equilibrium and non-equilibrium conditions are useful to probe the influence of temperature and other factors on stratum corneum macromolecular structure. 

However, the search for simple synthetic models is difficult and only very few functional biomimetic compounds exist so far. One of the factors, that hampers the successful design of synthetic analogs is the great complexity of biological systems which makes it almost impossible to pinpoint all the important fcictors of the cictive site that have to be included in a biomimetic analog. An accurate and realistic computer modeling of the enzymatic process could in principle be used to map out these crucial factors. In computer experiments the influence of different residues in the cictive site can be probed easily and environment and temperature effects can be assessed. To probe the capabilities of... 

The phase diagrams and ionic conductivities of anion-deficient ZrO2 compounds have been widely investigated, to probe the influence of both dopant size and concentration (e.g.. Ref. [95]). Whilst Sc" + doped systems possess the highest values of ionic conductivity, factors such as cost and long-term stability have favored the use of (Zri j,Yj,)O2 x/2 as the current "best material, in which the m t and t c transitions are observed at x 0.05 and xw0.16, respectively [96]. On increasing dopant (anion vacancy) concentration, the ionic conductivity initially increases with X, but reaches a maximum close to the lower limit of stability of the c phase and then decreases rapidly [97]. Many theoretical studies have attempted to provide an explanation for this effect, and it is generally accepted that vacancies are trapped... 

---