scholarly journals Single wedge sliding tests to investigate the mechanism of UHMWPE particle generation with microfabricated surface textures

2006 ◽  
Vol 25 (3) ◽  
pp. 424-434 ◽  
Author(s):  
Hsu-Wei Fang ◽  
Stephen M. Hsu ◽  
Jan V. Sengers
Author(s):  
Hsu-Wei Fang ◽  
Yu-Chih Su

Osteolysis induced by ultra-high molecular weight polyethylene (UHMWPE) wear particles has emerged as a critical failure mechanism of artificial joints. Many researchers have performed cell culture studies or animal tests to investigate the UHMWPE particles induced immunological responses. However, the effect of size and shape remains elusive. This is partly because of the difficulty in obtaining UHMWPE wear particles with specific sizes and shapes for bioactivity tests. Previously, we have shown the feasibility of producing narrowly distributed UHMWPE particle sizes and shapes by rubbing UHMWPE pins against textured surfaces [1]. The correlations between the surface texture dimensions and the size and shape of wear particles generated in water have been obtained [2]. In addition, this novel technique of UHMWPE particle generation enables the investigation of the effects of UHMWPE particle size and shape on bioactivity. It is concluded that the elongated particles and the particles which can be engulfed by macrophage cells induced stronger immunological responses [3]. Thus, it is possible to enhance the life of total joint replacements by reducing the production of the most toxic particle populations in terms of size and shape. Our idea is to apply surface textures on the articulating surface of joint implant in order to control the size and shape of UHMWPE wear particles. While maintaining a low wear rate of UHMWPE parts, further reduction of the most “toxic” particles released into human body shall prevent particle-induced osteolysis.


Author(s):  
Eugene J. Amaral

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.


Author(s):  
Marylyn Bennett-Lilley ◽  
Thomas T.H. Fu ◽  
David D. Yin ◽  
R. Allen Bowling

Chemical Vapor Deposition (CVD) tungsten metallization is used to increase VLSI device performance due to its low resistivity, and improved reliability over other metallization schemes. Because of its conformal nature as a blanket film, CVD-W has been adapted to multiple levels of metal which increases circuit density. It has been used to fabricate 16 MBIT DRAM technology in a manufacturing environment, and is the metallization for 64 MBIT DRAM technology currently under development. In this work, we investigate some sources of contamination. One possible source of contamination is impurities in the feed tungsten hexafluoride (WF6) gas. Another is particle generation from the various reactor components. Another generation source is homogeneous particle generation of particles from the WF6 gas itself. The purpose of this work is to investigate and analyze CVD-W process-generated particles, and establish a particle characterization methodology.


2019 ◽  
Vol 14 (4) ◽  
pp. 424-429 ◽  
Author(s):  
Ying Zhang ◽  
Liangcai Zeng ◽  
Zhenpeng Wu ◽  
Xianzhong Ding ◽  
Kuisheng Chen

1999 ◽  
Vol 169 (1) ◽  
pp. 72 ◽  
Author(s):  
Aleksandr A. Andreev ◽  
V.E. Yashin ◽  
Aleksandr V. Charukhchev

2021 ◽  
pp. 104279
Author(s):  
Thomas van Rompay ◽  
Iris van Ooijen ◽  
Sara Groothedde ◽  
Daniel Saakes
Keyword(s):  

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