Frozen inhomogeneities

When an infinite network is formed, the polymer chains in the network lose their freedom to move and are in a limited space. This results in non-cancellation of concentration fluctuations and in the emergence of position-dependent concentration fluctuations (i.e. fi ozen inhomogeneities). According to Shibayama et al. (Shibayama and Norisuye 2002 Shibayama 2006) there are four types of such frozen inhomogeneities in the gel state spatial, topological, mobility and coimectivity... 

Polycrystalline material and frozen solution differ in packing density and packing homogeneity. Polycrystalline material is normally characterized by high but inhomogeneous packing density, while for a frozen solution the reverse is observed,... 

Site-selection spectroscopy Maximum selectivity in frozen solutions or vapor-deposited matrices is achieved by using exciting light whose bandwidth (0.01-0.1 cm-1) is less than that of the inhomogeneously broadened absorption band. Lasers are optimal in this respect. The spectral bandwidths can then be minimized by selective excitation only of those fluorophores that are located in very similar matrix sites. The temperature should be very low (5 K or less). The techniques based on this principle are called in the literature site-selection spectroscopy, fluorescence line narrowing or energy-selection spectroscopy. The solvent (3-methylpentane, ethanol-methanol mixtures, EPA (mixture of ethanol, isopentane and diethyl ether)) should form a clear glass in order to avoid distortion of the spectrum by scatter from cracks. 

R. A. Marcus From the peak related to the inhomogeneous contribution, how large was the range of inhomogeneity in the AG changes, in absolute amount, in the system treated by Prof. Fleming Did this result refer to a highly viscous (e.g., frozen ) system ... 

More attention should be paid to specific analytical aspects. For instance, the handling of frozen or lyophilized fish material entails other effects and problems than fresh fish material does. Important issues with fresh fish material are, for example, inhomogeneity and formation of fat and/or water layers which could lead to incorrect subsampling and potentially to wrong analytical results and misinterpretations. 

The process of thawing bulky frozen foodstuffs is intrinsically slow this can have expensive consequences in industrial food processing and can be inconvenient in large and small catering and even at home (Miles et al., 1999). Besides time inefficiency, microbial contamination, inhomogeneous temperature distribution due to low conductivity, and prohibitive cost involved are problems that need to be solved (Miao et al., 2007). In order to address these concerns, new technologies have been proposed and analyzed. 

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