Thin-sectioning and microanalysis of individual extraterrestrial particles

A long standing constraint on the study of micrometeorites has centered on difficulties in preparing them for analysis. This is due largely to their small dimensions and consequent practical limitations on sample manipulation. Chondritic micrometeorites provide a good example; although much has been learned about their chemistry and mineralogy almost nothing was known about such basic properties as texture and petrographic associations. The only way to assess such properties is to examine microstructure indigenous to the particles. Unfortunately, almost all micrometeorites, out of necessity, have been crushed and dispersed onto appropriate substances prior to analysis, and most information about texture and petrography was lost. Recently, thin-sections of individual extraterrestrial particles have been prepared using an ultramicrotome equipped with a diamond knife. This procedure has been applied to stratospheric micrometeorites and Solar Max impact debris. In both cases the sections have enabled observation of a variety of internal particle features, including textures, porosity, and petrographic associations. The sectioning procedure is described and analysis results for chondritic micrometeoroids and select particles from Solar Max are presented

ART/Ada design project, phase 1. Task 1 report: Overall design

The design methodology for the ART/Ada project is introduced, and the selected design for ART/Ada is described in detail. The following topics are included: object-oriented design, reusable software, documentation techniques, impact of Ada, design approach, and differences between ART-IM 1.5 and ART/Ada 1.0 prototype. Also, Ada generator and ART/Ada runtime systems are discussed

A longitudinal analysis of the decision to drop out of post-compulsory education

In this paper we analyse the magnitude, timing, determinants and outcomes of dropping out of post-compulsory education over the period 1985-94. We use data from the Youth Cohort Surveys for England and Wales to estimate non-parametric single and competing risks duration models allowing for the effects of unobserved heterogeneity and time varying covariates. By the mid-1990s approximately 1 in 10 young people dropped out of post-compulsory education, especially in April and July. Dropouts were more likely to get jobs rather than become unemployed and the most important predictor of the likelihood of dropping out was prior attainment.

Development of a novel metastable composite material

The development of a new family of mouldable metastable composite materials has been demonstrated. Their special quality is derived from the ability to maintain the matrix as a supercooled liquid or gel whose solidification can be triggered mechanically, as desired, by a user. This article describes some aspects of the development work. In particular, the following are explained: the choice of matrix material; the use of additives to enhance the properties of the matrix; and the selection of reinforcement fibre. As part of the work, some mechanical testing was performed on several variations of a matrix-fibre pair and, to demonstrate the potential of such materials, some comparisons were made with a possible competitor material, a glass-reinforced urethane. It was shown that the metastable material could be formulated to provide mechanical properties that would make it suitable for applications such as orthopaedic casting, splinting and body armour, and in items of sports equipment, these being areas where its mouldability could be particularly desirable

A Conversation with Alan Gelfand

Alan E. Gelfand was born April 17, 1945, in the Bronx, New York. He attended public grade schools and did his undergraduate work at what was then called City College of New York (CCNY, now CUNY), excelling at mathematics. He then surprised and saddened his mother by going all the way across the country to Stanford to graduate school, where he completed his dissertation in 1969 under the direction of Professor Herbert Solomon, making him an academic grandson of Herman Rubin and Harold Hotelling. Alan then accepted a faculty position at the University of Connecticut (UConn) where he was promoted to tenured associate professor in 1975 and to full professor in 1980. A few years later he became interested in decision theory, then empirical Bayes, which eventually led to the publication of Gelfand and Smith [J. Amer. Statist. Assoc. 85 (1990) 398-409], the paper that introduced the Gibbs sampler to most statisticians and revolutionized Bayesian computing. In the mid-1990s, Alan's interests turned strongly to spatial statistics, leading to fundamental contributions in spatially-varying coefficient models, coregionalization, and spatial boundary analysis (wombling). He spent 33 years on the faculty at UConn, retiring in 2002 to become the James B. Duke Professor of Statistics and Decision Sciences at Duke University, serving as chair from 2007-2012. At Duke, he has continued his work in spatial methodology while increasing his impact in the environmental sciences. To date, he has published over 260 papers and 6 books; he has also supervised 36 Ph.D. dissertations and 10 postdocs. This interview was done just prior to a conference of his family, academic descendants, and colleagues to celebrate his 70th birthday and his contributions to statistics which took place on April 19-22, 2015 at Duke University.Comment: Published at http://dx.doi.org/10.1214/15-STS521 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org