Stretching strain

At break, 321, 324 At yield, 71, 72, 324 Tensile test, 319 Tensile, stretching strain, 226 Termination reaction rates for oxidation in PE, 58... 

Vascular endothelial cells under cyclic stretching are one of important factors to study [64]. As shown in Fig. 6C and 6D, upper microfluidic channel layer and bottom groove layer were separated by an elastic membrane that applies cyclic stretching strain to cells. A groove layer was attached under the elastic membrane and is connected to a vacuum pump that applies suction pressure to stretch the elastic membrane. Cells were cultured on top of the membrane and fluid flow is passed through the upper channel layer while vacuum pressure is applied to the stretched cells on the elastic membrane. The cells cultured on the membrane were cyclically stretched and relaxed. 

Shear rate viscosity (shear strain or stress) behavior is fundamental to controlling melt flow rheology. At low strain rate viscosity, the zero strain rate viscosity is directly related to extensional (stretching) strain... 

One cannot exclude decomposition as a thermally activated decay of interatomic bonds, which may occur as a result of a polymer chain scission affected by mechanical forces (i.e., stretching strain (o)) like that described for PMMA by Zhurkov et al. (scheme 4). ... 

In addition to stretching strain, an important role is also played by the M-O bond energy and the conformation of a cyclic compoimd formed in the process. There are numerous examples of the combined effect of stretching strain and thermal motion that results in a lowering of the potential barrier for the C-C bond rupture. Moreover, it has been shown by Enikolopyan et al. that strained crown-ether macrocycles open and polymerize upon exocyclic coordination to In con-... 

Elongation at break (the distance the material stretches (strained) before breaking). 

It is well recognized that a head impact produces both translational and rotational motion as well as deformation of the skull. Resultant brain injury may occur from both absolute motion of the brain and its relative displacement with respect to the skull. At present, there are several physical parameters used in the evaluation of head injury, including translational and/or rotational acceleration levels of head impact, impact force, velocity and kinetic energy, impulse and impact duration, etc. These measures have been widely used for animal, human cadaver, and dummy experimental data to determine tolerable and survival thresholds for head impact in translation or rotation. Other parameters such as skull displacement and stresses, brain pressures and strains, as well as neck stretch/strain are usually related to analytical and experimental head model studies. 

FIGURE 16.2 An automated materials testing apparatus typically applies a known stress on a dogbone-shaped sample and measures the resulting stretch (strain). A fixed or linear strain can also be programmed with the required force (or stress) measured as the sample is stretched. 

Temper Solution heat treatment in furnace Controlled stretching Strain hardening Natural ageing Normal artificial ageing Over-aging Extrusions... 

A characteristic property of polymers is the ability to be stretched (strained) when a force is applied (stress). Experimental measurements of this ability is complicated by the fact that in practice, polymers are not highly ordered. The limiting elastic modulus (strain/stress) is inferred by measuring the moduli of polymers of increasing crystallinity, and extrapolating to 100% crystalline polymer. 

The mechanical loading on a polymeric item not only changes its shape and sizes but also affect substantially its supramolecular structure. The mechanical loading on the amorphous-crystalline polymer (polyolefins) substantially influences first of all on the amorphous phase of the polymer. The stretching strain results in the conformational transitions the number of gauche conformations decreases and the number of trans conformations increases (polyethylene, poly(ethylene terephthalate)). Under strain chains of macromolecules are additionally oriented and the rotation of the rad-... 

The foregoing state of affairs appears to hold for living muscle. As myosin muscle is and must be extensible, but, as a living machine, it is contractile only. We are forced, therefore, to question the work of Hill (35) and others in which it was shown that muscle in the relaxed state resembles rubber, that the stretch-strain curves of the two are similar, that the stretching forces are of the same order of magnitude, and that both rubber and muscle exhibit the same anomalous thermoelastic behavior (at... 

---