Information transfer, mechanism

Heat transfer in micro-channels occurs under superposition of hydrodynamic and thermal effects, determining the main characteristics of this process. Experimental study of the heat transfer in micro-channels is problematic because of their small size, which makes a direct diagnostics of temperature field in the fluid and the wall difficult. Certain information on mechanisms of this phenomenon can be obtained by analysis of the experimental data, in particular, by comparison of measurements with predictions that are based on several models of heat transfer in circular, rectangular and trapezoidal micro-channels. This approach makes it possible to estimate the applicability of the conventional theory, and the correctness of several hypotheses related to the mechanism of heat transfer. It is possible to reveal the effects of the Reynolds number, axial conduction, energy dissipation, heat losses to the environment, etc., on the heat transfer. 

In the case of other systems in which one or both of the reactants is labile, no such generalization can be made. The rates of these reactions are uninformative, and rate constants for outer-sphere reactions range from 10 to 10 sec b No information about mechanism is directly obtained from the rate constant or the rate equation. If the reaction involves two inert centers, and there is no evidence for the transfer of ligands in the redox reaction, it is probably an outer-sphere process. 

The nuclear-encoded proteins are inserted into both inner and outer mitochondrial membranes, the intermembrane space, and the matrix and there are several different mechanisms involved. As mentioned above there is no apparent requirement for a presequence on proteins which insert specifically into the mitochondrial outer membrane. For proteins destined for the inner mitochondrial membrane, a stop-transfer mechanism is proposed. Thus some information in the peptide must stop the complete transfer of the protein into the mitochondrial matrix, enabling the protein to remain in the inner mitochondrial membrane. For some proteins in the intermembrane space (for example the Rieske iron-sulphur protein associated with the outer face of complex III), a particularly complicated import pathway... 

In contrast to the information transduction mechanism based on conformational change, the information transduction may effectively be performed through the electron transfer if the integrated molecular systems are composed of electronically active molecules. 

CMP processes also leave a metallic contamination typically in the 10"-10 at/cm range. These contaminants arise from the outcropping metals, the slurries, and the mechanical environment of the polishers. In front-end applications (STI), these levels are prohibited because they are not compatible with the following hot processes. In the case of back-end steps, these parasitic metals must be removed as well, even if this seems more paradoxical with the use of metallization steps. Indeed a large amount of charges at the interconnection level or the presence of mobile ions such as sodium or potassium can induce disturbances during the electrical information transfer. Furthermore, a superficial conductive metallic contamination can generate shorts between two adjacent lines by percolation conduction mechanism. And last but not least, fast diffusers such as copper can reach... 

Chemical shift correlated NMR experiments are the most valuable amongst the variety of high resolution NMR techniques designed to date. In the family of homonuclear techniques, four basic experiments are applied routinely to the structure elucidation of molecules of all sizes. The first two, COSY [1, 2] and TOCSY [3, 4], provide through bond connectivity information based on the coherent (J-couplings) transfer of polarization between spins. The other two, NOESY [5] and ROESY [6] reveal proximity of spins in space by making use of the incoherent polarization transfer (nuclear Overhauser effect, NOE). These two different polarization transfer mechanisms can be looked at as two complementary vehicles which allow us to move from one proton atom of a molecule to another proton atom this is the essence of a structure determination by the H NMR spectroscopy. 

There are a number of experiments using the proton transfer mechanism which may yet yield information regarding local compositions. A more polar solvent such as fluoroform may be able to support the proton in solution more... 

While the vast majority of studies on chiral induction were mainly concerned with the induction of the chiral (twisted) nematic or cholesteric phase, more recently induction of the smectic C phase in the smectic C has come to the fore, with a special emphasis on the way chirality is transferred between molecules [ 115]. It should also be noted that comparison of the chiral induction phenomena in the two types of LC phase and in other media can provide useful information concerning mechanisms of transfer and amplification of stereochemical information [116]. 

Mechanistic speculations about the molybdoenzymes must be considered to be in their infancy with the possible exception of those for xanthine oxidase. Although the detailed structural nature of the molybdenum site is unknown, there is sufficient information from biochemical and coordination chemistry studies to allow informed arguments to be drawn. Here we first discuss evidence for the nuclearity of the molybdenum site and then discuss both oxo-transfer and proton-electron transfer mechanisms for molybdenum enzymes. A final discussion considers the unique aspects of nitrogenase and the possible reasons for the use of molybdenum in enzymes. 

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