Creep-resistant composites of alumina and single-wall carbon nanotubes

Composites of alumina Al2O3 ceramic and single-wall carbon nanotubes (SWNTs) have been tested in uniaxial compression at 1300 and 1350 °C (Ar atmosphere), and they have been found to be about two orders of magnitude more creep-resistant compared to a pure alumina of about the same grain size (0.5 micras). This is attributed to partial blocking of grain-boundary sliding by SWNTs in the composites. Since the grain boundaries in the ceramic/SWNTs composites are amenable to being engineered, this constitutes an attractive approach to the design of creep-resistant ceramic composites

Multifaceted contributions : health workers and smallpox eradication in India

Smallpox eradication in South Asia was a result of the efforts of many grades of health-workers. Working from within the confines of international organisations and government structures, the role of the field officials, who were of various nationalities and also drawn from the cities and rural enclaves of the countries in these regions, was crucial to the development and deployment of policies. However, the role of these personnel is often downplayed in official histories and academic histories, which highlight instead the roles played by a handful of senior officials within the World Health Organization and the federal governments in the sub-continent. This article attempts to provide a more rounded assessment of the complex situation in the field. In this regard, an effort is made to underline the great usefulness of the operational flexibility displayed by field officers, wherein lessons learnt in the field were made an integral part of deploying local campaigns; careful engagement with the communities being targeted, as well as the employment of short term workers from amongst them, was an important feature of this work

Comment on "Effect of sintering temperature on a single-wall carbon nanotube-toughened alumina-based composite"

A recently published paper [D. Jiang, K. Thomson, J.D. Kuntz, J.W. Ager, A.K. Mukherjee, Scripta Mater. 56 (2007) 959] presents a discussion regarding the controversy surrounding toughening in alumina/single-wall carbon nanotubes composites, with specific reference to an earlier paper [X. Wang, N.P. Padture, H. Tanaka, Nature Mater. 3 (2004) 539] co-authored by one of us. Here we present a clarification contending that some of the arguments presented in that discussion are invalid. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved