Scales hidden

Computer simulations act as a bridge between microscopic length and time scales and tlie macroscopic world of the laboratory (see figure B3.3.1. We provide a guess at the interactions between molecules, and obtain exact predictions of bulk properties. The predictions are exact in the sense that they can be made as accurate as we like, subject to the limitations imposed by our computer budget. At the same time, the hidden detail behind bulk measurements can be revealed. Examples are the link between the diffiision coefficient and... 

The aspect of sample preparation and characterization is usually hidden in the smallprint of articles and many details are often not mentioned at all. It is, however, a very crucial point, especially with surface and interface investigations since there might be many unknown parameters with respect to surface contaminations, surface conformations, built-in stresses, lateral sample inhomogeneities, roughness, interfacial contact etc. This is in particular important when surfaces and interfaces are investigated on a molecular scale where those effects may be quite pronounced. Thus special care has to be taken to prepare well defined and artifact free specimens, which is of course not always simple to check. Many of these points are areas of... 

There is still a long way to go in the harmonisation of indices, applicability of new techniques and standardisation. These are essential steps in order to advance in the detection of the stressor effects by means of structural descriptors. However, even if these questions might be solved, the ability of structural descriptors to detect effects is limited. Many stressors occur in low concentrations, in acute episodes, or have side effects that are not reflected in the structure (composition, abundance) of the biofilm. In these cases where chronic effects would not occur, or are hidden, a finer scale of detection is required. 

The parsing of the transporter sequences into the TM domains shown in Fig. 1A represents the consensus result of three different methods. Average hydrophobicity was calculated with ProperTM using different window sizes and the Kyte and Doolittle scale (7). TMHMM, a hidden Markov model-based approach (8), and PHDHTM, a profile-based neural network method (9), were then utilized to refine the predictions. 

Gravitahonal (micro) lensing is now recognised as a way of revealing otherwise hidden matter. It is universally used to estimate the distribution and quantity of dark matter on a variety of distance scales. The study of dark matter in the halo of our own Galaxy is not the least significant amongst these. 

Nanoparticles have an exceptionally high ratio of surface area to volume—unlike bulky forms of matter, most of the material in nanoparticles is exposed rather than hidden inside the interior. This feature of nanoparticles can drastically alter the material s properties, which is another example of the changes that occur at the small end of the scale. Gold, for instance, is usually not very chemically active in its bulk form, yet gold nanoparticles are quite reactive. An example of this phenomenon will be described in the following section. 

The previously scaled atomic spectrum of a standard (technically, it is called a training pattern) enters the net throughout the input layer (a variable per node). Thus, an input neuron receives, simply, the information corresponding to a predictor variable and transmits it to each neuron of the hidden layer (see Figures 5.1, 5.3 and 5.4). The overall net input at neuron7 of the hidden layer is given by eqn (5.3), which corresponds to eqn (5.1) above ... 

To summarize, strict e-expansion a priori seems to yield unambiguous results. Closer inspection, however, reveals that in low order calculations considerable ambiguity is hidden in the definition of the physical observables used as variables or chosen to calculate. What is worse, the e-expansion does not incorporate relevant physical ideas predicting the behavior outside the small momentum range or beyond the dilute limit. In particular, it does not give a reasonable form for crossover scaling functions. On the other hand, it can be used to calculate well-defined critical ratios, which are a function of dimensionality only, Even then, however, the precise definition of the ratio matters,... 

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