Directionally solidified lamellar eutectic superalloys by edge-defined, film-fed growth

A program was performed to scale up the edge-defined, film-fed growth (EFG) method for the gamma/gamma prime-beta eutectic alloy of the nominal composition Ni-19.7 Cb - 6 Cr-2.5 Al. Procedures and problem areas are described. Flat bars approximately 12 x 1.7 x 200 mm were grown, mostly at speeds of 38 mm/hr, and tensile tests on these bars at 25 and 1000 C showed lower strength than expected. The feasibility of growing hollow airfoils was also demonstrated by growing bars over 200 mm long with a teardrop shaped cross-section, having a major dimension of 12 mm and a maximum width of 5 mm

Fireball/Blastwave Model and Soft Gamma-ray Repeaters

Soft gamma-ray repeaters are at determined distances and their positions are known accurately. If observed, afterglows from their soft gamma-ray bursts will provide important clues to the study of the so called "classical gamma-ray bursts". On applying the popular fireball/blastwave model of classical gamma-ray bursts to soft gamma-ray repeaters, it is found that their X-ray and optical afterglows are detectable. Monitoring of the three repeaters is solicited.Comment: Already published in 1998 in "Chinese Physics Letters", replaced with the published version. See astro-ph/0502452 for a more detailed versio

The Ulysses Supplement to the BATSE 3B Catalog of Cosmic Gamma-Ray Bursts

We present Interplanetary Network localization information for 218 gamma-ray bursts in the 3rd BATSE catalog, obtained by analyzing the arrival times of these bursts at the Ulysses and Compton Gamma-Ray Observatory (CGRO) spacecraft. For any given burst observed by these two spacecraft, arrival time analysis (or "triangulation") results in an annulus of possible arrival directions whose half-width varies between 7 arcseconds and 32 arcminutes, depending on the intensity and time history of the burst, and the distance of the Ulysses spacecraft from Earth. This annulus generally intersects the BATSE error circle, resulting in an average reduction of the error box area of a factor of 30.Comment: Accepted for publication in the Astrophysical Journal Supplemen

The Interplanetary Network Supplement to the BeppoSAX Gamma-Ray Burst Catalogs

Between 1996 July and 2002 April, one or more spacecraft of the interplanetary network detected 787 cosmic gamma-ray bursts that were also detected by the Gamma-Ray Burst Monitor and/or Wide-Field X-Ray Camera experiments aboard the BeppoSAX spacecraft. During this period, the network consisted of up to six spacecraft, and using triangulation, the localizations of 475 bursts were obtained. We present the localization data for these events.Comment: 89 pages, 3 figures. Submitted to the Astrophysical Journal Supplement Serie

Gravitationally Lensed Gamma-Ray Bursts as Probes of Dark Compact Objects

If dark matter in the form of compact objects comprises a large fraction of the mass of the universe, then gravitational lensing effects on gamma-ray bursts are expected. We utilize BATSE and Ulysses data to search for lenses of different mass ranges, which cause lensing in the milli, pico, and femto regimes. Null results are used to set weak limits on the cosmological abundance of compact objects in mass ranges from 10$^{-16}$ to 10$^{-9}$ $M_{\odot}$. A stronger limit is found for a much discussed $\Omega = 0.15$ universe dominated by black holes of masses $\sim 10^{6.5} M_{\odot}$, which is ruled out at the $\sim$ 90% confidence level.Comment: 14 pages, 4 figures, fixed minor corrections. Accepted for publication in ApJ(L

Physician Labour Supply in Canada: a Cohort Analysis

This paper employs cohort analysis to examine the relative importance of different factors in explaining changes in the number of hours spent in direct patient care by Canadian general/ family practitioners (GP/FPs) over the period 1982 to 2002. Cohorts are defined by year of graduation from medical school. The results for male GP/FPs indicate that: there is little age effect on hours of direct patient care, especially among physicians aged 35 to 55; there is no strong cohort effect on hours of direct patient care; but there is a secular decline in hours of direct patient care over the period. The results for female GP/FPs indicate that: female physicians on average work fewer hours than male physicians; there is a clear age effect on hours of direct patient care; there is no strong cohort effect; there has been little secular change in average hours of direct patient care. The changing behaviour of male GP/FPs accounted for a greater proportion of the overall decline in hours of direct patient care from the 80’s through the mid 90’s than did the growing proportion of female GP/FPs in the physician stock.physician, labour supply, hours, cohorts

AN ANALYSIS OF OCCUPATIONAL HEALTH IN PORK PRODUCTION

The rapid expansion of large-scale pork production has been accompanied by increasing concerns regarding potential detrimental consequences of environmental hazards on the health of producers. This study makes use of health indicators obtained from attendees at the World Pork Expo between 1991 and 1995 to evaluate the impact of pork production generally and of confinement production, specifically, on producer health. The analysis expands existing studies because the larger number of participants allows for detailed analysis, both nonfarmers and non-pork farmers are used as controls, both objective as well as self-reported health measures are considered, and personal characteristics such as height, weight, age, gender, smoking habits, and years of exposure to confinement operations and swine operations are controlled. The analysis shows that pork producers are more likely to report nagging respiratory symptoms (cough, sinus problems, sore throat) than are other farmers. Confinement operators have increased incidence of some symptoms relative to other pork producers. However, there was no evidence of permanent loss of pulmonary function associated with pork production or confinement operation. Farmers suffered from a greater incidence of hearing loss and loss of dominant hand strength relative to nonfarmers. Pork producers had even greater incidence of lost hand strength than other farmers but had no added incidence of hearing loss. On the plus side, farmers had lower blood pressure than did nonfarmers.

Physician Labour Supply in Canada: a Cohort Analysis

This paper employs cohort analysis to examine the relative importance of different factors in explaining changes in the number of hours spent in direct patient care by Canadian general/ family practitioners (GP/FPs) over the period 1982 to 2002. Cohorts are defined by year of graduation from medical school. The results for male GP/FPs indicate that: there is little age effect on hours of direct patient care, especially among physicians aged 35 to 55; there is no strong cohort effect on hours of direct patient care; but there is a secular decline in hours of direct patient care over the period. The results for female GP/FPs indicate that: female physicians on average work fewer hours than male physicians; there is a clear age effect on hours of direct patient care; there is no strong cohort effect; there has been little secular change in average hours of direct patient care. The changing behaviour of male GP/FPs accounted for a greater proportion of the overall decline in hours of direct patient care from the 80’s through the mid 90’s than did the growing proportion of female GP/FPs in the physician stock.physician, labour supply, hours, cohorts