High information content

The advantages of spectra for structure representation are their high information content and their easy, accurate, and reproducible measurement. On top of that, spectrometers provide this spectral information already in electronic form and therefore directly amenable to further processing. 

The basic methods of the identification and study of matrix-isolated intermediates are infrared (IR), ultraviolet-visible (UV-vis), Raman and electron spin resonance (esr) spectroscopy. The most widely used is IR spectroscopy, which has some significant advantages. One of them is its high information content, and the other lies in the absence of overlapping bands in matrix IR spectra because the peaks are very narrow (about 1 cm ), due to the low temperature and the absence of rotation and interaction between molecules in the matrix. This fact allows the identification of practically all the compounds present, even in multicomponent reaetion mixtures, and the determination of vibrational frequencies of molecules with high accuracy (up to 0.01 cm when Fourier transform infrared spectrometers are used). 

SP TR NRDB (or abbreviated SPTR) was created to overcome these limitations. SPTR provides a comprehensive, nonredundant and up-to-date protein sequence database with a high information content. The components are ... 

The hyphenation of CE and NMR combines a powerful separation technique with an information-rich detection method. Although compared with LC-NMR, CE-NMR is still in its infancy it has the potential to impact a variety of applications in pharmaceutical, food chemistry, forensics, environmental, and natural products analysis because of the high information content and low sample requirements of this method [82-84]. In addition to standard capillary electrophoresis separations, two CE variants have become increasingly important in CE-NMR, capillary electrochromatography and capillary isotachophoresis, both of which will be described later in this section. 

Hyphenation of chromatographic separations with NMR detection allows the acquisition of data sets with high information content. This is especially useful for... 

While NMR spectra possess a high information content, this confers a level of complexity that can be obstructive if a quick and simple answer is required. The use of NMR flow probes has reduced the time taken to acquire a spectrum to 2-3 min and flow NMR has consequently found considerable application in robot synthesis, multiple parallel synthesis (MPS) or combinatorial chemistry. Since H possesses 5600 times the receptivity of it is inevitable that it will continue to be the nucleus of choice in this area, complicating the analysis. Unless automatic analysis is able to transcend the aid to interpretation role and into the confirm or refute the structure role, the higher information content of the NMR spectrum constitutes a threat rather than an opportunity. 

The outcome of this is that although not easily interpretable by inspection (as for example in mid-infrared absorbance spectra) the NIR spectra of hydrocarbon streams possess a very high information content. Use of suitable chemometric methods allows for the reduction of this information content into extremely powerful predictive models for not only chemical compositional properties, but also bulk physical and fuel properties of hydrocarbon process streams and prodncts. ... 

In the geosciences Raman spectroscopy has traditionally been a laboratory tool for structural analysis of minerals. Recent developments in instrumentation make possible the use of Raman spectroscopy as a tool for routine identification of minerals in field situations. The following advantages characterize Raman analysis of minerals no sample preparation in situ real time measurement non-destructive and non-intrusive sampling samples may be transparent or opaque spectra are well resolved and with high information content. 

For complete identification, relevant direct information on the molecular structure of the analyte is always more specific and hence more reliable than indirect information. Analytical steps based on molecular spectroscopy all provide direct more or less detailed information on the structure of the analyte. This is particularly true for fourier-transform infrared (FTIR) and mass spectroscopy (MS), where the spectra have a very high information content. 

Then appears linear sweep rate voltammetry in which the electrode potential is a linear function of time. The current-potential curve shows a peak whose intensity is directly proportional to the concentration of electroactive species. If the potential sweep takes place in two directions, the method is named cyclic voltammetry. This method is one of the most frequently used electrochemical methods for more than three decades. The reason is its relative simplicity and its high information content. It is very useful in elucidating the mechanisms of electrochemical reactions in the case where electron transfer is coupled... 

While supercritical fluid chromatography seems to have a controversial benefit, supercritical fluid extraction (SFE) is a technique used world-wide and plays an important role in many industrial processes, such as the decaffei-nation of coffee. Due to the high information content of NMR spectroscopy, the hyphenation of SFE with NMR spectroscopy promises a deep insight into the extraction process itself, thus leading to a better understanding and development of more efficient extractions. 

Optical spectroscopy is a valuable complement to magnetochemical techniques for the study of exchange effects in polynuclear paramagnetic complexes. A recent review was given in Ref. ( 3). Dinuclear Cr + complexes have received a great deal of attention, mainly because (pf the sharpness and thus the high information content of their E <— A2 transitions. The complexes [a.CriOH Cra ], where a= NH3 or a2 = en, have been studied in great detail(5 6). They will serve as illustrative examples of the types of effects which are observed and the conclusions which can be drawn. 

We conclude that the high information content of the intracon-figurational transitions has enabled us to derive a very... 

As an instrumental approach to conventional electrophoresis, capillary electrophoresis offers the capability of on-line detection, micropreparative operation and automation (6,8,45-47). In addition, the in tandem connection of capillary electrophoresis to other spectroscopy techniques, such as mass spectrometry, provides high information content on many components of the simple or complex peptide under study. For example, it has been possible to separate and characterize various dynorphins by capillary electrophoresis-mass spectrometry (33). Therefore, the combination of CE-mass spectrometry (CE-MS) provides a valuable analytical tool useful for the fast identification and structural characterization of peptides. Recently, it has been demonstrated that the use of atmospheric pressure ionization using Ion Spray Liquid Chromatography/ Mass Spectrometry is well suited for CE/MS (48). This approach to CE/MS provides a very effective and straightforward method which allow the feasibility of obtaining CE/MS data for peptides from actual biological extracts, i.e., analysis of neuropeptides from equine cerebral spinal fluid (33). 

For high information-content displays, active-matrix (AM) pixel addressing provides improved display performance and reduced power consumption. In active matrix addressing each individual pixel is controlled by one or more thin-film transistors (TFTs). To date, most AM OLED displays have used polysilicon TFTs as the active elements, because they can provide sufficient current at low voltages and acceptable device dimensions, and they are capable of integrated drive electronics... 

The observation that some sequence positions are more tolerant to mutation initiated the application of information theory as a method to understand the importance of these residues to the structure and function of the protein (Reidhaar-Olson and Sauer, 1988). A residue that is intolerant to mutations has high information content, whereas a tolerant residue has low information content. By fixing the amino acid identities of residues as the fitness is improved, optimization acts to... 

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