Orientation general

Biaxially oriented films, made by stretching in two mutually perpendicular directions, have reduced creep and stress relaxation compared to unoriented materials. Part ot the effect is due to the increased modulus, but for brittle polymers, the improved behavior can be due to reduced crazing. Biaxial orientation generally makes crazing much more difficult in all directions parallel to the plane of the film. 

The magnetic quantum number m is related to the fact that only in an applied magnetic field it is possible to define a direction within the atom with respect to which the orbital can be directed. In general for a value of the orbital quantum number we have 21 + 1 possible values of the magnetic quantum number (which are 0, 1, 2,... up to ). To an s orbital, for instance, for which = 0 and is spherically symmetrical, only one value corresponds for the magnetic quantum number (m = 0). For p orbitals = 1) we have three possibilities (m = —1,0,+1) corresponding to three orientations (generally assumed as the x, y, z directions in Cartesian coordinates). Similarly we have five possibilities for d orbitals ( = 2) (that is m = —2, — 1,0, +1, +2), seven for/orbitals ( = 3), etc. 

Surface reconstruction or adsorption can often cause a vicinal surface with a single macroscopic orientation to facet into surfaces with different orientations. Generally the reconstruction occurs on a particular low-index flat face, and lowers its free energy relative to that of an unreconstructed surface with the same orientation. However the same reconstruction that produces the lower free energy for the flat face generally increases the energy of surface distortions such as steps that disturb the reconstmction. Thus reconstmction is often observed only on terraces wider than some critical terrace width Wc. When steps are uniformly distributed initially and if Wc is much greater... 

The general problem of simple diastereoselection (see Section A. 1.), as outlined below refers to the combination of two enantiofaces, which is possible in 4 different orientations (1, 3, 5 and 7). 1/7 and 3/5 are enantiomorphous and lead to enantiomeric pairs (2/8 and 4/6, respectively). In reactions with closed transition states , this means that the two olefins are in a syn orientation. Generally, this orientation is enforced by the transfer of a metal cation or a proton from D to A [ene-type reaction]8. D is a donor and A an acceptor group. 

The typical pattern of apical-anterior MI (QS in V1-V4) with more or less extension up to V6, but not in leads I and VL, is explained by the infarction vector directing posteriorly, but not rightwards, since not much lateral involvement is present (the 6 and 12 segment are spared). Consequently, the QRS loop is oriented generally posteriorly from the beginning and, sometimes, with initial forces directed anteriorly, but... 

Orient-ability. With the exception of both the EVOH grades, the remaining barrier resins were orientable. Generally, the amorphous resins SELAR PA 3426 and polyacrylic-imide XHTA-50A facilitated more uniform stretching when compared to semicrystalline resins, VDC copolymer and aromatic nylon MXD-6. 

The Kuparuk A formation is characterized as very fine-grained, vertically stratified, imbricated sandstones with relatively low permeability (horizontal air permeabilities on the order of tens to hundreds of millidarcies). They are interpreted as sand and mud deposits from storm-driven waves and currents deposited in a lower shoreface setting. The Kuparuk A sands consist of six separate sandstone bodies (Fig. 2), A1-A6 (base-to-top), that are interpreted to represent the erosional remnants of shorefaces. These remnant shorefaces are oriented generally SW-NE and step basinward, i.e. prograde, to the SE (Masterson Paris 1987). Ankerite (ferroan dolomite) cement locally occludes porosity, particularly in units A3 and A4. 

The mechanical properties of PLA can be enhanced by orientation, generally in machine direction orientation with a draw ratio from 2 to 3, and in transverse direction with a draw ratio from 2 to 4 [178]. Especially toughness... 

Orientation consists of a controlled stretching of the polymer chains of the film in such a way as to orient the chains in a direction parallel to the plane of the film. In general, all thermoplastics may be oriented the benefits are somewhat greater for some materials than others depending on the material and/or the particular characteristic that is to be improved. Orientation generally improves toughness, tensile strength, flexibility, and shrinkability. It may also be used to improve the clarity of transparent films and to decrease the gas and moisture permeability of some films. 

The yield strength of the polymer matrix published data. The orientation factor Cq values range from 0 (completely random fibers) to 1 (completely oriented). Generally, the latter quantity is not actually measured but used as a fitting parameter to equation (3). 

The orientation of the polymer matrix introduces an asymmetrical structure such that diffusion rates vary relative to the axis of orientation. Generally, the rate of penetration parallel to the axis is less than the rate in a randomly oriented sample, which in turn is less than the rate perpendicular to the axis. 

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