The relativistic precession of the orbits

The relativistic precession can be quickly inferred from the nonlinear polar orbit equation without actually solving it.Comment: Accepted for publication in Astrophysics & Space Scienc

Thick-Lift Paving with Tamper Bar Pavers

Project 0-7064This research studied thick-lift asphalt concrete construction using a tamper bar paver. Tamper bar pavers were deployed on three paving projects to place asphalt layers ranging from 6 to 10 inches thick. On each project, test sections were constructed in one and two lifts, evaluating different lift thicknesses, paver screed settings, and rolling patterns. The research team monitored the mat cooldown time; measured mat density throughout compaction; tested the mat after construction with a rolling density meter, 3D Radar, and an inertial roughness profiler; and sampled 172 cores for laboratory testing of air voids and air void uniformity

Optics of Nonuniformly Moving Media

A moving dielectric appears to light as an effective gravitational field. At low flow velocities the dielectric acts on light in the same way as a magnetic field acts on a charged matter wave. We develop in detail the geometrical optics of moving dispersionless media. We derive a Hamiltonian and a Lagrangian to describe ray propagation. We elucidate how the gravitational and the magnetic model of light propagation are related to each other. Finally, we study light propagation around a vortex flow. The vortex shows an optical Aharonov--Bohm effect at large distances from the core, and, at shorter ranges, the vortex may resemble an optical black hole.Comment: Physical Review A (submitted

Mental health needs and services in the West Bank, Palestine

Background Palestine is a low income country with scarce resources, which is seeking independence. This paper discusses the high levels of mental health need found amongst Palestinian people, and examines services, education and research in this area with particular attention paid to the West Bank. Methods CINAHL, PubMed, and Science Direct were used to search for materials. Results and conclusion Evidence from this review is that there is a necessity to increase the availability and quality of mental health care. Mental health policy and services in Palestine need development in order to better meet the needs of service users and professionals. It is essential to raise awareness of mental health and increase the integration of mental health services with other areas of health care. Civilians need their basic human needs met, including having freedom of movement and seeing an end to the occupation. There is a need to enhance the resilience and capacity of community mental health teams. There is a need to increase resources and offer more support, up-to-date training and supervision to mental health teams

Field measurements of horizontal forward motion velocities of terrestrial dust devils: towards a proxy for ambient winds on Mars and Earth

Dust devils – convective vortices made visible by the dust and debris they entrain – are common in arid environments and have been observed on Earth and Mars. Martian dust devils have been identified both in images taken at the surface and in remote sensing observations from orbiting spacecraft. Observations from landing craft and orbiting instruments have allowed the dust devil translational forward motion (ground velocity) to be calculated, but it is unclear how these velocities relate to the local ambient wind conditions, for (i) only model wind speeds are generally available for Mars, and (ii) on Earth only anecdotal evidence exists that compares dust devil ground velocity with ambient wind velocity. If dust devil ground velocity can be reliably correlated to the ambient wind regime, observations of dust devils could provide a proxy for wind speed and direction measurements on Mars. Hence, dust devil ground velocities could be used to probe the circulation of the martian boundary layer and help constrain climate models or assess the safety of future landing sites. We present results from a field study of terrestrial dust devils performed in the southwest USA in which we measured dust devil horizontal velocity as a function of ambient wind velocity. We acquired stereo images of more than a hundred active dust devils and recorded multiple size and position measurements for each dust devil. We used these data to calculate dust devil translational velocity. The dust devils were within a study area bounded by 10 m high meteorology towers such that dust devil speed and direction could be correlated with the local ambient wind speed and direction measurements. Daily (10:00 to 16:00 local time) and two-hour averaged dust devil ground speeds correlate well with ambient wind speeds averaged over the same period. Unsurprisingly, individual measurements of dust devil ground speed match instantaneous measurements of ambient wind speed more poorly; a 20-minute smoothing window applied to the ambient wind speed data improves the correlation. In general, dust devils travel 10-20% faster than ambient wind speed measured at 10 m height, suggesting that their ground speeds are representative of the boundary layer winds a few tens of meters above ground level. Dust devil ground motion direction closely matches the measured ambient wind direction. The link between ambient winds and dust devil ground velocity demonstrated here suggests that a similar one should apply on Mars. Determining the details of the martian relationship between dust devil ground velocity and ambient wind velocity might require new in-situ or modelling studies but, if completed successfully, would provide a quantitative means of measuring wind velocities on Mars that would otherwise be impossible to obtain

Neoliberal methods of disqualification: a critical examination of disability-related education funding in Canada

Funding for post-secondary students with disabilities in Canada is an under-studied yet pressing policy issue that affects up to 15% of students currently enrolled in post-secondary institutions across the country reflecting, at the same time, trends in educational accommodations occurring on a global scale. This article presents new data and combines these findings with a qualitative policy review to expose how funding levels in Canada have remained static over a 20-year period as a result of changes to key funding programs. We show how access to these insufficient funding programs is based on application processes that are shaped by the careful management of knowledge and information, underpinned by a desire to keep spending low. We then analyze the implications of these funding practices for disabled students and situate their effects within the neoliberal cultural project that eschews transparency while increasing individualization and self-responsibilization – encouraging disabled students to embody market rationalities as a way of maintaining their presence in academia