skip navigation


Register for Latest Research

Stay Informed
Register with NCJRS to receive NCJRS's biweekly e-newsletter JUSTINFO and additional periodic emails from NCJRS and the NCJRS federal sponsors that highlight the latest research published or sponsored by the Office of Justice Programs.

NCJRS Abstract

The document referenced below is part of the NCJRS Virtual Library collection. To conduct further searches of the collection, visit the Virtual Library. See the Obtain Documents page for direction on how to access resources online, via mail, through interlibrary loans, or in a local library.


NCJ Number: 148187 Find in a Library
Journal: Journal of the Forensic Science Society  Volume:34  Issue:1  Dated:(January-March 1994)  Pages:11-16
Author(s): H Katterwe
Date Published: 1994
Page Count: 6
Type: Report (Study/Research)
Format: Article
Language: English
Country: United Kingdom
Annotation: This paper reports on experiments designed to reveal erased numbers in recently developed and technically more significant polymers.
Abstract: Experiments with acoustic microscopy at an ultrasonic frequency of 50 MHz were unsuccessful; however, experiments that used swelling techniques with various solvents, relief polishing, and heat treatment were successful. The experiments revealed that thermomechanically treated regions of a polymer have a higher swelling capacity under the influence of solvents than untreated regions. Results show that polymers have a "mechanical memory." The heating process showed similar "memory effects" to those observed by Hosemann et al during experiments on the deformation of polyethylene. Apparently, each crystallite is transformed by stretching into microcrystallites that lie together like a string of pearls and form parts of the so-called ultrafibrils of the stretched material. The domains may only regain their original shape near the melting point if the microcrystallites are interconnected by chain molecules that do not lose this contact during the stretching process. The tie molecules are able to raise the entropy of the colloidal structure to the highest possible value, and the sample returns to its original shape. 4 figures and 14 references
Main Term(s): Science and Technology
Index Term(s): Erased identification restoration; Forensic sciences; Investigative techniques; Police; Polymer analysis
Note: Based on a paper presented at the Forensic Science Society meeting in Lyon, May 1991.
To cite this abstract, use the following link:

*A link to the full-text document is provided whenever possible. For documents not available online, a link to the publisher's website is provided. Tell us how you use the NCJRS Library and Abstracts Database - send us your feedback.