The residual stress field of HIPed Si3N4 rolling elements were studied. Two kinds of HIPed Si3N4 ball blanks self-finished at different nominal lapping loads ranging from 1.3kgf/ball to 10.87kgf/ball and four kinds of commercially finished 1⁄2′′ (12.7mm) HIPed Si3N4 balls before, during and after RCF tests were investigated. The experimental results showed that in the finishing process of HIPed...

The recent emergence of online feedback and sampling mechanisms has created new avenues where consumers can learn about information goods such as books, music, and movies. An increasing number of studies evaluate the impact of these technological innovations on purchasing behavior. These studies often face estimation issues such as unobserved heterogeneity and simultaneity. This paper reviews t...

The water cycle in the western United States changed dramatically over glacial cycles. In the past 20,000 years, higher precipitation caused desert lakes to form which have since dried out. Higher glacial precipitation has been hypothesized to result from a southward shift of Pacific winter storm tracks. We compared Pacific Ocean data to lake levels from the interior west and found that Great B...

The objective of this paper is to identify the incentives and barriers to marriage among cohabiting women, especially disadvantaged mothers who are targets of welfare reform. We use the newly released cohabitation data from the National Longitudinal Survey of Youth (1979-2000), which tracks the partners of cohabiting women across survey waves. Our results support several conclusions. First, coh...

This study was designed to investigate the effects of three countermeasures--landscaping, building a fence and prohibitive signs--on the frequency of trespassing, which in this case means crossing the track at places where it is forbidden. At each location the official route was no more than 300 m away. The main results showed that the effect of each countermeasure on the frequency of trespassi...

As high speed rail is becoming increasingly popular around the globe, alignments are being forced onto marginal land due to land costs and the requirement for straight tracks. Rail foundations spread the applied wheel loads to prevent damage to the underlying in-situ soil upon which tracks are built. Designs which cannot sustain the resulting stresses will cause serviceability issues and will r...

Introduction: According to the American Society of Radiation Oncology, all patients receive radiation therapy during their illness, where radiation is delivered by the medical linear accelerator (Linac). The aim of this study was to evaluate the quality assurance (QA) of the Linac in analyzing the used dose profile in the treatment of cancer tumors. Materi...

Shoulder stability depends on the position of the arm as well as activities of the muscles around the shoulder. The capsulo-ligamentous structures are the main stabilisers with the arm at the end-range of movement, whereas negative intra-articular pressure and concavity-compression effect are the main stabilisers with the arm in the mid-range of movement.There are two types of glenoid bone loss...

Calculating track thrust with track functions. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. In e þ e À event shapes studies at LEP, two different measurements w...

Thin film Ni-Cu diffusion couples (individual layer thicknesses: 50 nm) were prepared by direct-current magnetron sputtering on silicon substrates. Interdiffusion and solid-solution formation, the associated changes of microstructure and the evolution of mechanical stresses of the Ni-Cu diffusion couples during thermal treatments were investigated employing ex-situ X-ray diffraction phase and t...