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1. Med any delayed response to a stimulus or agent
2. Psychol any illusory sensation caused by a stimulus that has ceased



the change in the state of strain of a solid in a constant stressed state. A simple case of the aftereffect can be observed in a cylindrical specimen acted on by a constant tensile force P, as illustrated in Figure 1. With time, the strain in the rod increases, (curve ab), and in the general case there is an increase in both the elastic and the plastic deformation. This phenomenon is called the direct aftereffect. The increase in elastic deformation is a manifestation of the elastic aftereffect, and the increase in plastic deformation indicates creep. If at some moment t1 the load is removed, the specimen is immediately shortened to the extent of the elastic deformation (bd), and then a slow contraction of the specimen with time (de)—the reverse aftereffect—is observed.

Figure 1. The elastic aftereffect in a material

The elastic aftereffect without creep is observed in solids whose stressed state nowhere exceeds the elastic limit, and it is classified as a slow reversible process. The elastic aftereffect is usually due to the nonuniformity of the elastically stressed state of actual solids and to the tendency of the stressed state to equalization. The aftereffect explains the phenomenon of elastic hysteresis. For metals, the elastic aftereffect is small, but in organic substances—such as leather, textile fibers, and plastics—it can be of considerable magnitude.

The plastic aftereffect in materials, or creep, is associated with a substantial change in the molecular or crystalline structure of materials and ultimately is a consequence of atomic rearrangements. Aftereffects are investigated in rheology.


References in periodicals archive ?
The only after-effect was the length of time it took to get my own "plumbing" to resume full function, which took not only the two weeks in Germany, but also three weeks after I returned to the U.
The after-effect of ultrasound on the chemically modified sample (physical-chemical modification) reduced the deformation (CA-US).
The "most worrying" after-effect of the September 11 attacks remains the limited support the cause has found in Western societies.
an after-effect, as opposed to a person literally being hung over something.
That said, Rik's personality is still slightly manic, and it's given extra edge by his obviously fragmented memory, the one remaining after-effect of his near-fatal quad bike accident in 1998.
One thing to keep in mind, however, is that rental programs are created in the best interest of the student body; profits, if any, are an after-effect.
The would-be conqueror Black Mustafa certainly could nut have imagined such an after-effect of the coffee bags he lost at Vienna.
The after-effect of the rash of mergers and acquisition has been the formation of many start-up companies that need space to accommodate their needs.
European airports have had to institute extraordinary airport security procedures since the late 1970s, but when the US awoke from its deep security sleep (with the advent of 9/11) the after-effect has been that the security imbalance has become so great that it is now threatening the aviation industry on a global scale.
The main after-effect of the procedure is a watery discharge, which patients have experienced for up to 3 weeks following the ablation.
Maybe it's an after-effect of the infection I got from spending thirty days in a ditch.
But, as Farmer notes, "perhaps the worst after-effect of episodes of brutality is that, in general, they mark the beginning of persecution, not the end.