Modelling of AlAs/GaAs interfacial structures using high-angle annular dark field (HAADF) image simulations

High angle annular dark field (HAADF) image simulations were performed on a series of AlAs/GaAsinterfacial models using the frozen-phonon multislice method. Three general types of models were considered—perfect, vicinal/sawtooth and diffusion. These were chosen to demonstrate how HAADFimage measurements are influenced by different interfacialstructures in the technologically important III–V semiconductor system. For each model, interfacial sharpness was calculated as a function of depth and compared to aberration-corrected HAADF experiments of two types of AlAs/GaAs interfaces. The results show that the sharpness measured from HAADF imaging changes in a complicated manner with thickness for complex interfacialstructures. For vicinal structures, it was revealed that the type of material that the probe projects through first of all has a significant effect on the measured sharpness. An increase in the vicinal angle was also shown to generate a wider interface in the random step model. The Moison diffusion model produced an increase in the interface width with depth which closely matched the experimental results of the AlAs-on-GaAs interface. In contrast, the interface width decreased as a function of depth in the linear diffusion model. Only in the case of the perfect model was it possible to ascertain the underlying structure directly from HAADFimage analysis

Portable machine welding head automatically controls arc

Portable weld tool makes weld repairs out-of-station and on the side opposite the original weld. It provides full automatic control of the arc voltage, current, wire feed, and electrode travel speed in all welding attitudes. The device is readily adaptable to commercially available straight polarity dc weld packs

FORC Analysis of homogeneous nucleation in the two-dimensional kinetic Ising model

The first-order reversal curve (FORC) method is applied to the two-dimensional kinetic Ising model. For the system size and magnetic field chosen, the system reverses by the homogeneous nucleation and growth of many droplets. This makes the dynamics of reversal nearly deterministic, in contrast to the strongly disordered systems previously studied by the FORC method. Consequently, the FORC diagrams appear different from those obtained in previous studies. The Kolmogorov-Johnson-Mehl-Avrami (KJMA) theory of phase transformation by nucleation and growth is applied to the system. Reasonable agreement with the Monte Carlo simulations is found, and the FORC method suggests how the KJMA theory could be extended.Comment: 3 pages, 2 figures, presented at 2004 MMM meeting, to appear in conference proceedings in J. Appl. Phys. (May 2005); rephrased several section

The Economic Legacy of Divorced and Separated Women in Old Age

Although progress has been made over the last 20 years, the burden of a low income in old age is still carried by unattached women. Few researchers, however, have examined exactly where the burden of poverty falls within the category of unattached older women or the nature of this poverty. Like any other group of older Canadians, unattached women are not a homogenous population. The category of 'unattached' includes the separated, divorced, widowed and ever single, all of whom face different circumstances in old age because of differences over the life course. Using SLID data we examine income and sources of income from 1993 to 1999 to identify differences among these groups. The findings indicate that the separated and divorced are the poorest of all older unattached women in Canada. A key source of the difference is the growth in private pension incomes.low income; old age; unattached women; SLID

Willingness-to-Pay for Improved Air Quality in Hamilton-Wentworth: A Choice Experiment

Prepared for Hamilton-Wentworth Air Quality Initiative pursuant to a memorandum of understanding among McMaster University, the Ontario Ministry of Environment and Energy and the Regional Municipality of Hamilton-Wentworth, dated November 5, 1996.

Persistence and Academic Success in University

We use a unique set of linked administrative data sets to explore the determinants of persistence and academic success in university. The explanatory power of high school grades greatly dominates that of other variables such as university program, gender, and neighbourhood and high school characteristics. Indeed, high school and neighbourhood characteristics, such as average standardized test scores for a high school or average neighbourhood income, have weak links with success in university.University Success, High School, Neighbourhood

Persistence and Academic Success in University

We use a unique set of linked administrative data sets to explore the determinants of persistence and academic success in university. The explanatory power of high school grades greatly dominates that of other variables such as university program, gender, and neighbourhood and high school characteristics. Indeed, high school and neighbourhood characteristics, such as average standardized test scores for a high school or average neighbourhood income, have weak links with success in university.university success, high school, neighbourhood.

Shifting Skill Demand and the Canada-US Unemployment Gap: Evidence from Prime-Age Men

This paper considers the possible role of shifts in labour demand away from unskilled workers, combined with an institutionally- generated greater labour supply elasticity in Canada, in explaining the apparent secular increase in Canadian male unemployment, and in explaining the emergence of the Canada-U.S. unemployment rate gap in the 1980's. Using comparable data on annual weeks worked and unemployed in both countries, we identify four main facts which are consistent with such this explanation: Both Canada and the US experienced wage polarization over this period, with substantial real wage declines for unskilled men; annual weeks worked fell disproportionately among unskilled workers in both countries; responses of weeks worked to wage declines were more elastic in Canada; and aggregate movements out of employment over this period corresponded closely to movements into unemployment in Canada. Interestingly, however, unskilled U.S. men were more likely than Canadians to leave the labour force as their employment fell, adding further to the Canada-U.S. unemployment gap. As well, some fairly substantial decreases in weeks worked are observed quite high up in the Canadian wage distribution, where wages did not fall appreciably. The latter changes cannot easily be explained by a shifts in labour demand alone.

Usefulness and Usability of a Personal Health Record and Survivorship Care Plan for Colorectal Cancer Survivors: Survey Study

Background: As a result of improvements in cancer screening, treatment, and supportive care, nearly two-thirds of individuals diagnosed with colorectal cancer (CRC) live for 5 years after diagnosis. An ever-increasing population of CRC survivors creates a need for effective survivorship care to help manage and mitigate the impact of CRC and its treatment. Personal health records (PHRs) and survivorship care plans provide a means of supporting the long-term care of cancer survivors. Objective: The purpose of this study is to characterize the usefulness of a CRC PHR and survivorship care plan and to describe the usability of these technologies in a population of CRC survivors. To our knowledge, this is the first study to assess a PHR and survivorship care plan specifically targeting CRC survivors. Methods: Twenty-two patients with CRC were recruited from surgery clinics of an academic medical center and Veterans Affairs hospital in Indianapolis and provided access to an online Colorectal Cancer Survivor’s Personal Health Record (CRCS-PHR). Survey data were collected to characterize the usefulness of the CRCS-PHR and describe its usability in a population of CRC survivors. CRC survivors were surveyed 6 months after being provided online access. Means and proportions were used to describe the usefulness and ease of using the CRC website. Open-ended questions were qualitatively coded using the constant comparative method. Results: CRC survivors perceived features related to their health care (ie, summary of cancer treatment history, follow-up care schedule, description of side effects, and list of community resources) to be more useful than communication features (ie, creating online relationships with family members or caregivers, communicating with doctor, and secure messages). CRC survivors typically described utilizing traditional channels (eg, via telephone or in person) to communicate with their health care provider. Participants had overall positive perceptions with respect to ease of use and overall satisfaction. Major challenges experienced by participants included barriers to system log-in, lack of computer literacy or experience, and difficulty entering their patient information. Conclusions: For CRC, survivors may find the greater value in a PHR’s medical content than the communication functions, which they have available elsewhere. These findings regarding the usefulness and usability of a PHR for the management of CRC survivorship provide valuable insights into how best to tailor these technologies to patients’ needs. These findings can inform future design and development of PHRs for purposes of both cancer and chronic disease management