Ionizing radiation isnt generally thought of as good for you, but its good for artificial hips. A new reference material from the National Institute of Standards and Technology (NIST) will help researchers determine what methods of irradiating the plastic parts in joint replacements during manufacturing will best increase their wear resistance.
Reference Material 8457 is intended to help address concerns about the long-term durability of orthopedic hip implants amid growing use of these devices in younger, more active patients. It is well known that radiation can create new chemical bonds between adjacent molecular chains in a special form of polyethylene used to make the socket for the metal ball and shaft in an artificial hip. This "crosslinking" creates a structure that resists sliding forces and wear. Manufacturers and researchers need to control radiation conditions to achieve the intended wear resistance; too much radiation causes brittleness, and too little can result in poor wear resistance.
The NIST material consists of 10 small, identical cubes of polyethylene. The cubes are intended for use as control samples in a new ASTM International standard test method. The method involves immersing cubes in an organic liquid and measuring how much the material swells. Samples that expand the most have the least amount of crosslinking. Each reference material comes with a certificate that provides precise cube dimensions and information about swelling from a series of round-robin tests involving six laboratories.
Laura Ost | EurekAlert!
Melting solid below the freezing point
23.01.2017 | Carnegie Institution for Science
An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering