XMM-Newton observation of the highly magnetised accreting pulsar Swift J045106.8-694803: evidence of a hot thermal excess

Several persistent, low luminosity (LX ~ 1034 erg s-1), long spin period (P > 100 s) High Mass X-ray Binaries have been reported with blackbody components with temperatures > 1 keV. These hot thermal excesses have correspondingly small emitting regions (< 1 km2) and are attributed to the neutron star polar caps. We present a recent XMM-Newton target of opportunity observation of the newest member of this class, Swift J045106.8-694803. The period was determined to be 168.5 ± 0.2 s as of 17 July 2012 (MJD = 56125.0). At LX ~ 1036 erg s-1, Swift J045106.8-694803 is the brightest member of this new class, as well as the one with the shortest period. The spectral analysis reveals for the first time the presence of a blackbody with temperature kTBB = 1.8 +0.2-0.3 keV and radius RBB = 0.5 ± 0.2 km. The pulsed fraction decreases with increasing energy and the ratio between the hard (> 2 keV) and soft (< 2 keV) light curves is anticorrelated with the pulse profile. Simulations of the spectrum suggest that this is caused by the pulsations of the blackbody being ~ π out of phase with those of the power law component. Using a simple model for emission from hot spots on the neutron star surface, we fit the pulse profile of the blackbody component to obtain an indication of the geometry of the system

Evaluating the Design Process of a Four-Bar-Slider Mechanism Using Uncertainty Techniques

With limited resources and time available for a typical design project, it is difficult to decide how to allocate these resources and time to produce an optimum design. Also, the question arises, ?Given the design process, available resources, and available time, will the design meet the program goals?? Uncertainty analyses of design processes addresses these issues and could substantially improve design quality, cost, and cycle time. Research to examine uncertainty in the design process employs previous experience in experimental, model, and manufacturing uncertainty, in an innovative approach for analyzing the entire design process. This research was initiated with a pilot project, a 4-bar-slider mechanism. Two new theories for the research have arisen from this pilot project. First, design optimization techniques could be used to compare steps of the design process and to help determine the overall uncertainty of the final manufactured product. Second, manufacturing uncertainty can be included as an additional random uncertainty in the analysis of the final manufactured product. While more research needs to be completed to test, apply, and expand on these theories, the pilot project has been a positive step forward. It has already produced two proposals with one funded and one awaiting a decision. This research, although in its beginning stages, could substantially improve the design process

Medication Regulations of the California Horse Racing Industry: Are Changes Needed to Prevent the Use of Illegal Drugs

This Comment addresses the prominence of horse racing in California and the resulting tendency of some trainers to administer performance enhancing drugs to race horses. Some have advocated banning the use of medications for race horses all together. The author argues that such a ban is not the best solution. More effective means are available to curb the use of illegal drugs in racing. The author suggests more accurate drug testing programs and increasing the penalties for those who are caught drugging race horses

Survey of the relative importance which fifth and sixth-grade teachers place on the teaching of map and globe skills

Thesis (Ed.M.)--Boston Universit