Extrinsic forces

Research has previously shown that bacteria are not uniformly distributed in soil, reflecting soil structure and available nutrients (Richaume et al., 1993). The distribution of microorganisms throughout the soil can also be considered from the applied ecological perspective of patch dynamics, where patch formation is a reflection of intrinsic and extrinsic forces (Rao et al., 1986). The same authors also showed spatial variability in the degradation of pesticides applied to a soil system. 

The Palmaz stent as a balloon expandable stent has a specific complication profile. Once the stent is compressed due to extrinsic forces, e.g., an enlarging tumor mass, adjacent vascular structures, or a vigorous cough, it has no abihty to reexpand. Compression of a Palmaz stent has been noted in a patient with a thoracic aortic aneurysm (Slonim et al. 1998), in a patient after severe coughing (Hautmann and Huber 1996), and in two patients with external malignant tumors (Beer et al. 1999). 

Visceral motility is described by Barral and Mercier as an "intrinsic, active motion." Each organ possesses this motion independent of extrinsic forces. This occurs in two phases, which Barral and Mercier name "expir" and "inspir". In "expir," the organs move toward the midline of the body, and during "inspir" they move away from the midline in a rotational manner. The rotations appear to occur around the axes of their embryologic origin. These motions may be related to the craniosacral rh5frhm. 

An isolated mammalian heart whose extrinsic nervous connections have been severed will beat spontaneously for hours if it is supplied with a nutrient medium via the aortic trunk and coronary arteries (Langendorff preparation). In such a preparation, only those drugs that act directly on cardio-myocytes will alter contractile force and beating rate. 

The coercive force of a powder is an extrinsic property, which is influenced by many factors such as size and shape and packing density. Maghemite particles prepared from directly precipitated spindle-type hematite particles showed a tendency of increase in coercive force with decrease in particle size, and increase in their aspect ratios (31). However, a quantitative relationship between the coercive force and size and/or aspect ratio is still not available. 

Unlike intrinsic semiconductors, in which the conductivity is dominated by the exponential temperature aud band-gap expression of Eq. (6.31), the conductivity of extrinsic semiconductors is governed by competing forces charge carrier density and charge carrier mobility. At low temperatures, the number of charge carriers initially... 

Nonequihbrium concentrations of point defects can be introduced by materials processing (e.g. rapid quenching or irradiation treatment), in which case they are classified as extrinsic. Extrinsic defects can also be introduced chemically. Often times, nonstoichiometry results from extrinsic point defects, and its extent may be measmed by the defect concentration. Many transition metal compounds are nonstoichiometric because the transition metal is present in more than one oxidation state. For example, some of the metal ions may be oxidized to a higher valence state. This requires either the introduction of cation vacancies or the creation of anion interstitials in order to maintain charge neutrality. The possibility for mixed-valency is not a prerequisite for nonstoichiometry, however. In the alkah hahdes, extra alkah metal atoms can diffuse into the lattice, giving (5 metal atoms ionize and force an equal number... 

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