Nuclear magnetic resonance Mobile

It is an unfortunate fact that several preexisting theories have tried to explain complicated mechanical phenomena of CB-reinforced rubbery materials but they have not been so successful." " However, a recent report might have a capability of explaining them collectively," when the author accepted the existence of the component whose molecular mobility is different from that of matrix mbber component in addition to the existence of well-known bound rubber component. The report described that this new component might be the most important factor to determine the reinforcement. These mbber components have been verified by spin-spin relaxation time 2 by pulsed nuclear magnetic resonance (NMR) technique, ° while the information obtained by NMR is qualitative and averaged over the sample and, therefore, lacking in the spatial... 

Yoshika, S., Aso, Y., Izuutsu, K., Terao, T. Stability of beta-galactosidase, a model protein drug, is related to water mobility as measured by oxygen-17 nuclear magnetic resonance (NMR). Pharm. Res. 10 (1), p. 103-108, 1993... 

The objectives of this review are to discuss the fundamental and more recently discovered properties of water alone and to critically examine the system properties and measurement methods used to measure the mobility of water and solids in foods—specifically water activity, nuclear magnetic resonance (NMR), and the glass transition. 

Throughout this review, the concept of mobility has been highlighted as a key parameter for understanding and predicting the processability and stability of food systems. Mobility is the common denominator of the three methods examined in this review—water activity, nuclear magnetic resonance, and glass transition. An emerging aspect of the picture for food... 

Bell, L.N., Bell, H.M., and Glass, T.E. 2002. Water mobility in glassy and rubbery solids as determined by oxygen-17 nuclear magnetic resonance Impact on chemical stability. Lebensm. 

Vittadini, E., Dickinson, L.C., and Chinachoti, P. 2002. NMR water mobility in xanthan and locust bean gum mixtures Possible explanation of microbial response. Carbohydr. Polym. 49, 261-269. Wachner, A.M. and Jeffrey, K.R. 1999. A two-dimensional deuterium nuclear magnetic resonance study of molecular reorientation in sugar/water glasses. J. Chem. Phys. Ill, 10611-10616. Wagner, W. and Pruss, A. 1993. International equations for the saturation properties of ordinary water substance Revised according to the international temperature scale of 1990. J. Phys. Chem. Ref. Data 22, 783-787. 

To detect dynamic featnres of colloidal preparations, additional methods are required. Nuclear magnetic resonance spectroscopy allows a rapid, repeatable, and noninvasive measurement of the physical parameters of lipid matrices withont sample preparation (e.g., dilution of the probe) [26,27]. Decreased lipid mobility resnlts in a remarkable broadening of the signals of lipid protons, which allows the differentiation of SLN and supercooled melts. Because of the different chemical shifts, it is possible to attribute the nuclear magnetic resonance signal to particnlar molecnles or their segments. 

The impact strength increases almost linearly with gel content and thus with the degree of crosslinking (17). Figure 9.3 shows the increase of the molecular mobility with the impact strength for ABS. For HIPS it is claimed that the situation is quite similar. The molecular mobility of the soft phase particles is determined by nuclear magnetic-resonance spectroscopy relaxation measurements (16). 

The models in Figures 2 and 3 show that a part of the low molecular weight liquid obviously separates the polymer chains from each other, thus facilitating segment mobility. Another part of it fills the cavities and displays almost liquid state behavior in them. This rather simplified model of the glass structure has been verified in some by nuclear magnetic resonance experiments. 

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