aftereffect

(redirected from aftereffects)
Also found in: Dictionary, Thesaurus, Medical, Legal.

aftereffect

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

Aftereffect

 

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.

D. D. IVLEV

References in periodicals archive ?
The finding suggests that much of the early processing of motion in the brain, such as that required for the motion aftereffect, depends on how an observer directs his or her attention to a moving object, writes Oliver Braddick of the University of Cambridge, England, in an accompanying commentary.
Despite a recession, a closed IPO window and the lingering aftereffects of 9/11, biotech and pharmaceutical companies are moving forward with their R&D and product development plans," says John Sterling, managing editor of GEN.
He spent two years recovering in an Army hospital, and even 80 years later, he said, doctors believe the aftereffects are causing him circulation problems.
Animated and rendered in 3D Studio Max, painted in Photoshop, composited with AfterEffects, and edited with Softimage DS.
With the victims and their mother in attendance, the father told the court that the girls are in counseling and are struggling with the aftereffects of the molestation, Bliss said.
HOCKEY: New York Rangers center Pat LaFontaine, feeling the aftereffects of a concussion, said his season was over but, he hopes, not his career.
Daltrey's still suffering the aftereffects of the eye-socket fracture he sustained last year, when Gary Glitter swung his microphone on stage and accidentally connected with Daltrey.
While most the club felt the aftereffects of the victory over Seattle on Thursday, Vaught came back strong, hitting 15 of 18 shots, including a jumper with two minutes left that gave the Clippers a 107-103 lead.
While Fairfield's tour-flow and sales were not immune to the aftereffects of September 11, Hanning believes the company's balanced portfolio of resort locations in both fly-to and drive-to destinations helped Fairfield rebound quickly.
The CDC study is expected to link some of the veterans' health problems to chronic fatigue syndrome and the physical aftereffects of battlefield stress.
Upon removal of the perturbation, movement aftereffects were observed in the direction opposite of the force perturbation (e.
WORLD number 14 Andy Murray insisted he had suffered no aftereffects from the wrist injury which had ruled him out since mid-May as he returned to claim a 6-4 6-4 victory in the first round of the Rogers Cup in Montreal.