SOFT analysis

Linden, H. B. (2002). Quick soft analysis of sensitive samples under inert conditions by insource liquid injection FD. In Proceedings of the 50th Annual Conference on Mass Spectrometry and Allied Topics, Orlando 2002, MPL 373. 

The proof proceeds in principle as a natural generalization of that established for the finite-range case. It presents an ingenious combination of soft analysis (repeated use of Schauder-Tychonov theorem) and hard analysis (tricky majorizations, etc.), which we do not want to reproduce here. It should, however, be noticed that we can show explicitly for these (one-dimensional) models that the effect of the boundary conditions adopted for the computation of the Gibbs state does disappear in the thermodjmamic limit. This is a reflection of the fact that these models do not exhibit phase transitions. 

Linden, H. B. Quick Soft Analysis of Sensitive Samples Under Inert Conditions by In-Source Liquid Injection FD, ASMS Orlando, 2002 pp. MPL 373. 

A multi-dimensional generalization of the Stefan problem which includes surface tension is studied as a mathematical model for growth in a metastable medium. Planar solutions are shown to exist for all time only if the data is sufficiently small, otherwise the velocity of the front becomes infinite in finite time. Planar fronts which exist for all time are shown to be morphologically unstable without surface tension and to be stable with respect to perturbations of short wavelength when surface tension is included. Above a critical value of the surface tension, planar fronts are completely stable. The mathematical techniques used are a combination of soft analysis based on the maximum principle and functional analytic/integral equation type hard estimates. 

The theory predicts high stabilities for hard acid - hard base complexes, mainly resulting from electrostatic interactions and for soft acid - soft base complexes, where covalent bonding is also important Hard acid - soft base and hard base - soft acid complexes usually have low stability. Unfortunately, in a quantitative sense, the predictive value of the HSAB theory is limited. Thermodynamic analysis clearly shows a difference between hard-hard interactions and soft-soft interactions. In water hard-hard interactions are usually endothermic and occur only as a result of a gain in entropy, originating from a liberation of water molecules from the hydration shells of the... 

McDevitt, V. L. Rodriquez, A. Williams, K. R. Analysis of Soft Drinks UV Spectrophotometry, Liquid Chromatography, and Capillary Electrophoresis, 1998, 75, 625-629. 

Graham, R. C. Robertson, J. K. Analysis of Trihalomethanes in Soft Drinks, /. Chem. Educ. 1988, 65, 735-737. Trihalomethanes are extracted from soft drinks using a liquid-liquid extraction with pentane. Samples are analyzed using a packed column containing 20% OV-101 on 80/100 mesh Gaschrom Q equipped with an electron capture detector. 

Tandem mass spectrometry or ms/ms was first introduced in the 1970s and gained rapid acceptance in the analytical community. The technique has been used for stmcture elucidation of unknowns (26) and has the abiUty to provide sensitive and selective analysis of complex mixtures with minimal sample clean-up (27). Developments in the mid-1980s advancing the popularity of ms/ms included the availabiUty of powerhil data systems capable of controlling the ms/ms experiment and the viabiUty of soft ionisation techniques which essentially yield only molecular ion species. 

The dynamic mechanical properties of VDC—VC copolymers have been studied in detail. The incorporation of VC units in the polymer results in a drop in dynamic modulus because of the reduction in crystallinity. However, the glass-transition temperature is raised therefore, the softening effect observed at room temperature is accompanied by increased brittleness at lower temperatures. These copolymers are normally plasticized in order to avoid this. Small amounts of plasticizer (2—10 wt %) depress T significantly without loss of strength at room temperature. At higher levels of VC, the T of the copolymer is above room temperature and the modulus rises again. A minimum in modulus or maximum in softness is usually observed in copolymers in which T is above room temperature. A thermomechanical analysis of VDC—AN (acrylonitrile) and VDC—MMA (methyl methacrylate) copolymer systems shows a minimum in softening point at 79.4 and 68.1 mol % VDC, respectively (86). 

The analysis of penicillins by mass spectrometry (qv) has developed with the advent of novel techniques such as fast atom bombardment. The use of soft ionization techniques has enabled the analysis of thermally labile nonvolatile compounds. These techniques have proven extremely valuable in providing abundant molecular weight information from underivatized penicillins, both as free acids and as metal salts (15). 

Einely divided samples may be identified further by analyses of the graphite ash, and identification of the minerals associated with the graphite and comparison with graphites from known sources. Owing to its softness and opaqueness, most of the graphitic carbon must be removed from the sample before analysis by either method. There are two general ways of accomplishing this. 

The analysis investigation and expert practical persons shows that in recently aside from the most wide-spread and known material letter such as ink for fountain-pen and soft-tip pen, pastes for bail-point pens and other, object technician-of criminal law study document all more often become the more modem material a letter, in particular gell ink handle, which are worked out, basically, foreign company (Japan, USA, Germany, Korea, China). 

To answer questions regarding dislocation multiplication in Mg-doped LiF single crystals, Vorthman and Duvall [19] describe soft-recovery experiments on <100)-oriented crystals shock loaded above the critical shear stress necessary for rapid precursor decay. Postshock analysis of the samples indicate that the dislocation density in recovered samples is not significantly greater than the preshock value. The predicted dislocation density (using precursor-decay analysis) is not observed. It is found, however, that the critical shear stress, above which the precursor amplitude decays rapidly, corresponds to the shear stress required to disturb grown-in dislocations which make up subgrain boundaries. 

Nonnal mode analysis was first applied to proteins in the early 1980s [1-3]. Much of the literature on normal mode analysis of biological molecules concerns the prediction of functionally relevant motions. In these studies it is always assumed that the soft normal modes, i.e., those with the lowest frequencies and largest fluctuations, are the ones that are functionally relevant. The ultimate justification for this assumption must come from comparisons to experimental data. Several studies have been made in which the predictions of a normal mode analysis have been compared to functional transitions derived from two X-ray conformers [4-7]. These smdies do indeed suggest that the low frequency normal modes are functionally relevant, but in no case has it been found that the lowest frequency normal mode corresponds exactly to a functional mode. Indeed, one would not expect this to be the case. 

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