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Structure component, defined

The adduced results have shown that loosely packed matrix of devit-rificated amorphous phase and disordered in deformation process crystalline phase part are structural components, defining impact energy dissipation and hence, impact toughness of semicrystalline polymers. The fractal analysis allows correct quantitative description of processes, occurring at HDPE impact loading. It is important, that the intercommunication exists between polymer initial structure characteristics and its changes in deformation process [2, 3]. [Pg.204]

Thus, the values of 3, v and t are boundary magnitudes for indicating which structural component defines its behaviour. At P. = P the clusters are such a component or, more precisely, a percolation cluster frame, identified with the cluster network. At P < p.j, polymer behaviour is defined by the combined influence of clusters and the loosely packed matrix. At p.j. = v the loosely packed matrix will define the structural component, at p.,. = it is defined by the chemical crosslinking network and at v < p.j, < the combined influence of the two components indicated above is observed. [Pg.251]

Thus, the percolation critical indices P and V are border values for P, indicating which structural component of an epoxy polymer defines its behaviour. At P = P nanoclusters or, more precisely, the percolation cluster network, identified with the nanocluster network, are such a component. At P < P < v epoxy polymer behaviour is defined by the combined influence of the nanoclusters and the loosely packed matrix. At P = V the loosely packed matrix will be a structural component, defining epoxy polymer behaviour. The estimations according to Equations 5.4 and 5.5 have shown that in the considered case the average d value is equal to 2.644 and then according to Equations 9.43 and 9.44 let us obtain p = 0.38, v = 0.76. Then, using Equation 5.49, P values for the considered epoxy polymers can be calculated [66]. [Pg.458]

Hence, the results stated above have shown that the order parameter index of a thermal cluster, by which the structure of the considered epoxy polymers is simulated, decreases with growth in the relative fraction of nanoclusters and its variation makes up 0.38-0.76 and this means that the loosely packed matrix and nanoclusters are structural components defining the behaviour of epoxy polymers, and the role of nanoclusters grows as their contents increase. The thermal cluster model allows the glass transition temperature of epoxy polymers as a function of the relative fraction of nanoclusters to be predicted. The order parameter index of the thermal cluster... [Pg.460]

Only a small amount of work has been done up to now concerning the prediction of bond strengths and other properties based on the results of the analysis of the resin. Ferg et al. [59] worked out correlation equations evaluating the chemical structures in various UF-resins with different F/U molar ratios and different types of preparation on the one hand and the achievable internal bond as well as the subsequent formaldehyde emission on the other hand. These equations are valid only for well defined series of resins. The basic aim of such experiments is the prediction of the properties of the wood-based panels based on the composition and the properties of the resins used. For this purpose various structural components are determined by means of - C NMR and their ratios related to board results. Various papers in the chemical literature describe examples of such correlations, in particular for UF, MF, MUF and PF resins [59-62]. For example one type of equation correlating the dry internal bond (IB) strength (tensile strength perpendicular to the plane of the panel) of a particleboard bonded with PF adhesive resins is as follows [17]... [Pg.1053]

As is the case with many members of Lamiaceae, Satureja douglasii produces abundant essential oil from glandular trichomes on the leaves. Gas chromatographic analysis of the leaf oils from specimens collected throughout the species range revealed the presence of some dozen and a half well-known compounds. The major compounds identified were camphene [215], camphor [216], which, taken together, were considered to comprise the bicyclic type, carvone [217], pulegone [218], menthone [219], and isomenthone [220] (see Fig. 2.68 for structures 215-220). The predominance of each of these major components defined a terpene type. (All compounds were observed in each of the terpene types, most in comparatively small amounts, some only as traces.)... [Pg.106]

Many structural components of the tight junctions (TJs) have been defined since 1992 [85-97]. Lutz and Siahaan [95] reviewed the protein structural components of the TJ. Figure 2.7 depicts the occludin protein complex that makes the water pores so restrictive. Freeze-fracture electronmicrographs of the constrictive region of the TJ show net-like arrays of strands (made partly of the cytoskeleton) circumscribing the cell, forming a division between the apical and the basolateral... [Pg.18]

As these results and Fig. 2 show, three structural components may be defined in lipid A (/) the lipid A backbone consisting of a pyranosidic HexN disaccharide and phosphate groups, (ii) substituents of the backbone phosphate residues (polar head groups), and (iii) fatty acids. Therefore, lipid A of different bacteria may be classified according to the nature of the backbone constituents (GlcpN or GlcpN3N), the type and nature of the polar head groups, and features of the acylation pattern. In a few instances, other backbone substituents have been encountered. These will be described later in conjunction with individual lipid A forms. [Pg.216]

The density of He I at the boiling point at 1 atm is 125 kg m 3 and the viscosity is 3 x 10 6 Pa s. As we would anticipate, cooling increases the viscosity until He II is formed. Cooling this form reduces the viscosity so that close to 0 K a liquid with zero viscosity is produced. The vibrational motion of the helium atoms is about the same or a little larger than the mean interatomic spacing and the flow properties cannot be considered in classical terms. Only a quantum mechanical description is satisfactory. We can consider this condition to give the limit of De-+ 0 because we have difficulty in defining a relaxation when we have the positional uncertainty for the structural components. [Pg.80]

This discussion puts us in a position to define a set of structural and evolutionary objects the tracing of whose history via homology, as implied by sequence similarity, is the primary aim of sequence analyses. The simple view of protein folding produces a small set of structural components to consider. This is the set of regular secondary structures the amphipathic a helix, the transmembrane or hydrophobic a. helix, the... [Pg.163]

Mass spectrometers use the difference in mass-to-charge ratio (m/z) of ionized atoms, molecular fragments, or whole molecules to differentiate between them. Mass spectrometry is therefore useful for quantitation of atoms or molecules and also for determining chemical and structural information about them [329, 531-533]. Molecules have distinctive fragmentation patterns which provide information to identify structural components. The general operation of a mass spectrometer is to (1) create gas-phase ions, (2) separate the ions in space or time based on their mass-to-charge ratio, and (3) measure the quantity of ions of each mass-to-charge ratio. The ion separation power of a mass spectrometer is described by the resolution, which is defined as ... [Pg.73]

RNA molecules are unable to form extended double helices, and are therefore less highly ordered than DNA molecules. Nevertheless, they have defined secondary and tertiary structures, and a large proportion of the nucleotide components enter into base pairings with other nucleotides. The examples shown here are 5S-rRNA (see p. 242), which occurs as a structural component in ribosomes, and a tRNA molecule from yeast (see p.82) that is specific for phenylalanine. [Pg.86]

The application of force to a stationary or moving system can be described in static, kinematic, or dynamic terms that define the mechanical similarity of processing equipment and the solids or liquids within their confines. Static similarity relates the deformation under constant stress of one body or structure to that of another it exists when geometric similarity is maintained even as elastic or plastic deformation of stressed structural components occurs [53], In contrast, kinematic similarity encompasses the additional dimension of time, while dynamic similarity involves the forces (e.g., pressure, gravitational, centrifugal) that accelerate or retard moving masses in dynamic systems. The inclusion of tune as another dimension necessitates the consideration of corresponding times, t and t, for which the time scale ratio t, defined as t = t It, is a constant. [Pg.80]

Now we fix a Riemannian metric g which is invariant under the T-action. The symplectic form co together with the Riemannian metric g gives an almost complex structure I defined by co(v, x) = g(Iv, w). With this almost complex structure, we regard the tangent space TxX as a complex vector space. Let XT = Cv be the decomposition into the connected components. For each x G C , we have the weight decomposition... [Pg.52]

The structure of yint depends, in general, on the nature of the solute-solvent interaction considered by the solvation model. As already noted in the contribution by Tomasi, a good solvation model must describe in a balanced way all the four fundamental components of the solute-solvent interaction electrostatic, dispersion, repulsion, charge transfer. However, we limit our exposition to the electrostatic components, this being components of central relevance, also for historical reason, for the development of QM continuum models. This is not a severe limitation. As a matter of fact, the QM problem associated with the solute-solvent electrostatic component defines a general framework in which all the other solute-solvent interaction components may be easily collocated, without altering the nature of the QM problem [5],... [Pg.83]

For the purpose of this chapter, we define an immobilized enzyme as a composite consisting of two essential components the noncatalytic structural component (carrier) and the catalytic functional component, the enzyme. Therefore, an immobilized enzyme has to be characterized by two sets of variables, the noncatalytic and the catalytic parameters [87]. [Pg.219]


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See also in sourсe #XX -- [ Pg.62 ]




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Structural components

Structure defined

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