MagIC system

This is a respectable type of separation, and yet it is obvious that not all compounds or classes of compounds are separated precisely and neatly from each. There simply is not such a magic system, and one must realize that further fractionation may be necessary. It is interesting to note that phosphatidylcholine and sphingomyelin tend to blend together. Usually the more unsaturated phosphatidylcholine species elute early on, followed by the more saturated one. By judicious handling of solvent eluate volume (by a fraction collector), a quite reasonable separation can be obtained. 

Iron, which was the metal symbolising strength in magical systems, used to be given to people suffering from weakness, and no doubt many were benefited, some psychologically (placebo reactors) and others because the weakness was due to iron deficiency anaemia. The rational use of iron could not begin tmtil both the presence of iron in the... 

In subsequent years (1988), the MAGIC system was commerciahzed, first by Hewlett-Packard (nowadays Agilent Technologies), and subsequently by other instrument manufacturers. Four commercial versions of the system have been available (1) the particle-beam interface, featuring an adjustable concentric pneumatic nebulizer, (2) the thermabeam interface with a combined pneumatic-TSP nebulizer, (3) the universal interface, in which TSP nebulization and an additional gas diffusion membrane is applied, and (4) the capillary-EI interface, which resulted from systematic modifications to existing PBI systems by Cappiello [83]. The first system was most widely used, and is discussed in more detail below. For some years, PBI was widely used for environmental analysis, especially in the US. 

It is an irony that one reason for the time lag in capitalizing on Flemings work for almost a decade was the appearance of the sulfonamides in 1935. These undoubtedly galvanized many of the medicinal chemists and pharmacologists into investigations. The work of Chain, Florey, and others finally resulted in the recognition of penicillins almost magical systemic effectiveness. By then World War II was already under way. As a result, much of the successful work of that period was not published until the war was over. 

Fig. 4 Energy of the first excited 2+ state in even nuclei in the calcium chain of isotopes. This chain contains two doubly magic systems with Ca and In both cases the first 2+ state lies at a very high excitation energy compared to the neighboring isotopes...

The main focus on shell gaps in the study of superheavy elements has always been the next spherical shell closure for protons and neutrons. However, since the majority of heavy and superheavy nuclei are well deformed, it is also important to understand the effects of deformed shell closures in lighter systems. Here too doubly magic systems can be found, albeit with a different understanding of the magic character. 

NMR has developed into a powerfiil analytical teclmique in the past decades, and has been used extensively in the characterization of a great number of chemical systems. Its extension to the study of surfaces, however, has been hampered by the need of large samples because of its poor sensitivity. On the otiier hand, the development of magic-angle-spiiming NMR (MAS-NMR) and the extension of NMR to many nuclei besides... 

The correction term in Eq. (9) shows that the basic assumption of additivity of the fragmental constants obviously does not hold true here. Correction has to be appHed, e.g., for structural features such as resonance interactions, condensation in aromatics or even hydrogen atoms bound to electronegative groups. Astonishingly, the correction applied for each feature is always a multiple of the constant Cu, which is therefore often called the magic constant . For example, the correction for a resonance interaction is +2 Cj, or per triple bond it is -1 A detailed treatment of the Ef system approach is given by Mannhold and Rekker [5]. 

The high acidity of superacids makes them extremely effective pro-tonating agents and catalysts. They also can activate a wide variety of extremely weakly basic compounds (nucleophiles) that previously could not be considered reactive in any practical way. Superacids such as fluoroantimonic or magic acid are capable of protonating not only TT-donor systems (aromatics, olefins, and acetylenes) but also what are called (T-donors, such as saturated hydrocarbons, including methane (CH4), the simplest parent saturated hydrocarbon. 

Maghemite [12134-66-6] Magic acid Magic Acid MagicAcid [33843-68-4] Magic Carpet system Magma... 

The Magic Carpet system (AstroTurf Industries) (13) is a novel installation technique in which turf and adherent underpad are unwound from a core and floated onto the subbase of a playing field by air pressure suppHed from ducts in the base. To expose the subbase for other sports uses, the turf—pad combination is roUed up and stored at the edge of the field or in a recessed storage compartment. 

The term magic acid coined in G. A. Olah s laboratory for the non-aqueous system HSOaF/SbFs. 

This graphic perspective system was transposed into a magical context by John Dee who believed that pictures drawn according to the single-point perspective system could become a type of magical mirror. Dee produced his own treatise on perspective which is found... 

As holds for other cluster systems, certain magic cluster electron counts exist, which indicates for a certain cluster-halide ratio and interstitial present the filling of all bonding molecular orbitals and therefore the thermodynamically most stable situation. For main group interstitial atoms these are 14 cluster-based electrons whereas for transition-metal interstitials the magic number is 18 [1, 10-12]. All of these phases are synthesized by high-temperature solid-state chemical methods. A remarkable variety of different structure types has been... 

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