Stress effect

Hou, L. and Nassehi, V., 2001. Evaluation of stress - effective flow in rubber mixing. Nonlinear Anal. 47, 1809-1820. 

Melt Viscosity. The study of the viscosity of polymer melts (43—55) is important for the manufacturer who must supply suitable materials and for the fabrication engineer who must select polymers and fabrication methods. Thus melt viscosity as a function of temperature, pressure, rate of flow, and polymer molecular weight and stmcture is of considerable practical importance. Polymer melts exhibit elastic as well as viscous properties. This is evident in the swell of the polymer melt upon emergence from an extmsion die, a behavior that results from the recovery of stored elastic energy plus normal stress effects. 

Normal Stress (Weissenberg Effect). Many viscoelastic fluids flow in a direction normal (perpendicular) to the direction of shear stress in steady-state shear (21,90). Examples of the effect include flour dough climbing up a beater, polymer solutions climbing up the inner cylinder in a concentric cylinder viscometer, and paints forcing apart the cone and plate of a cone—plate viscometer. The normal stress effect has been put to practical use in certain screwless extmders designed in a cone—plate or plate—plate configuration, where the polymer enters at the periphery and exits at the axis. 

The interface between the substrate and the fully developed film will be coherent if the conditions of epitaxy are met. If there is a small difference between the lattice parameter of the film material and the substrate, die interface is found to contain a number of equally spaced edge dislocations which tend to eliminate the stress effects arising from the difference in the atomic spacings (Figure 1.13). 

Study of transverse shearing stress effects is divided in two parts. First, some exact elasticity solutions for composite laminates in cylindrical bending are examined. These solutions are limited in their applicability to practical problems but are extremely useful as checl oints for more broadly applicable approximate theories. Second, various approximations for treatment of transverse shearing stresses in plate theory are discussed. 

The treatment of transverse shear stress effects in plates made of isotropic materials stems from the classical papers by Reissner [6-26] and Mindlin [6-27. Extension of Reissner s theory to plates made of orthotropic materials is due to Girkmann and Beer [6-28], Ambartsumyan [6-29] treated symmetrically laminated plates with orthotropic laminae having their principal material directions aligned with the plate axes. Whitney [6-30] extended Ambartsumyan s analysis to symmetrically laminated plates with orthotropic laminae of arbitrary orientation. 

The reduced oxidation near sample corners is related to these stress effects, either by retarded diffusion or modified interfacial reactionsManning described these stresses in terms of the conformational strain and distinguished between anion and cation diffusion, and concave and convex surfaces. He defined a radial vector M, describing the direction and extent of displacement of the oxide layer in order to remain in contact with the retreating metal surface, where ... 

Champoux, R. L., Analytical Experimental Methods of Residual Stress Effects in Fatigue, ASTM, STP 1004,1989. 

If the effect of water stress is to alter regulation of the pathway such that the rate constant for reaction A G is increased or A CP is decreased (which would have an overall effect of conserving nitrogen), then the fractionation at G can be shown to be thereby increased. At present this is speculative, but in fact explanations for the water-stress effect using flow-models are rather constrained. For example, it is not possible to relate what might happen at the kidneys (e.g., resorption of urea) to the amino acid body pool, since the urea cycle is non-reversible. It should be possible to design experiments that test this suggestion. 

Z = Vp/p is named as the characteristic length which contributes to the couple stress effect. 

Ivanovici, A.M. Wiebe, W.J. (1981). Towards a working definition of stress A review and critique. In Stress Effects on Natural Ecosystems, ed. G. W. Barrett R. Rosenberg, pp. 13-27. New York Wiley. 

The use of stress terminology has been discussed in Chapter 1, where it was pointed out that the value of the term stress in indicating some adverse force or influence lies in its extreme generality, without the need for a precise quantification. Nevertheless it is appropriate that a scientific discipline should be concerned with definable quantities. This will be the starting point for this paper, which will follow the example of Levitt (1972) who applied the concepts and terminology of mechanical stress (force per unit area) and strain (a definable dimension change) to the study of plant responses to the environment. This approach will be developed here in an attempt to incorporate the philosophies behind stress effects into a general treatment of the responses of ecosystems to adverse environmental conditions. 

Powles, S.B. Bjorkman, O. (1982a). High light and water stress effects on photosynthesis in Nerium oleander. II. Inhibition of photosynthetic reaction under water stress interaction with light level. Carnegie Institute of Washington Year Book, 81, 76-7. 

These five contributions provide an up-to-date report on stress effects is given. 

Holden PA, LJ Halverson, MK Firestone (1997) Water stress effects on tolnene biodegradation by Pseudomonas putida. Biodegradation 8 143-151. 

C. P. P. Reid and J. G. Mexal, Water stress effects on root exudation of lodgepole pine. Soil. Biol. Biochem. 9 417 (1977). 

B. Analysis of Fe Stress Effects on Microbial Community Structure on Barley Roots... 

Patients prescribed intranasal steroids should be instructed to shake the product gently before each use and prime the pump before the first use or if not used for more than 1 week. Clear nasal passages before use, and avoid nose blowing for 10 to 15 minutes after use. Rare cases of septal perforation have been reported therefore, administration of the spray away from the septum should be stressed. Effects are not immediate, and regular use is... 

MacDougall, J. M., Musante, L., Castillo, S., and Acevedo, M.C., Smoking, caffeine, and stress Effects on blood pressure and heart rate in male and female college students. Health Psychology 7, 461-478, 1988. 

Sheridan, J.F. et al., Psychoneuroimmunology Stress effects on pathogenesis and immunity during infection, Clin. Microbiol. Rev., 7, 200, 1994. 

Publication gravure printing inks apparently show elastic behavior at D = 105 s the modulus of shearing G is 103 Pa. This indicates that at high shear rates D, between 105 and 106 s gravure printing inks develop normal stress effects and thus show a hydrodynamic lubricating effect. These deductions are relevant to an... 

Between 7 and 470 K a is found to increase with temperature. This increase is reversible and corresponds well with that of bulk silicon [Ko4]. If PS is annealed in nitrogen at higher temperatures (600 °C), hydrogen desorption takes place, which changes the condition of the inner surface drastically. At these temperatures an irreversible increase in a is observed for micro PS. A similar increase in a after annealing is found for meso PS. Changes that affect the core of the crystallites, e.g. stress effects [Ko4], as well as surface-related effects like the formation of surface states [Ko5, BalO], are proposed to be responsible for the observed increase of a with T. 

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