Supernova Remnants and Plerions in the Compton Gamma-Ray Observatory Era

Due to observations made by the Compton Gamma-Ray Observatory over the last six years, it appears that a number of galactic supernova remnants may be candidates for sources of cosmic gamma-rays. These include shell-type remnants such as IC443 and $\gamma$ Cygni, which have no known parent pulsars, but have significant associations with unidentified EGRET sources, and others that appear to be composite, where a pulsar is embedded in a shell (e.g. W44 and Vela), or are purely pulsar-driven, such as the Crab Nebula. This review discusses our present understanding of gamma-ray production in plerionic and non-plerionic supernova remnants, and explores the relationship between such emission and that in other wavebands. Focuses include models of the Crab and Vela nebulae, the composite nature of W44, the relationship of shell-type remnants to cosmic ray production, the relative importance of shock-accelerated protons and electrons, constraints on models placed by TeV, X-ray and radio observations, and the role of electrons injected directly into the remnants by parent pulsars.Comment: 21 pages, including 4 eps figures, invited review, to appear in Proc. 4th Compton Symposium, (1997) ed. Dermer, C. D. & Kurfess, J. D. (AIP, New York

Advanced Conducting Project

Shenandoah by Frank Ticheli -- Angel Band: III. Finale by Walter S. Hartley -- Petite Symphonie: No. 2 Andante Cantabile by Charles Gounod -- Amazing Grace by Frank Ticheli -- Fire Dance by David Shaffer -- Royal Crown March by Bruce Pearson and Barrie Gott -- Prophesy by Sean O\u27Loughlin -- Music from The Hunger Games by Michael Brown -- The Magic of Harry Potter by Michael Story -- On a Hymnsong of Philip Bliss by David Holsinger

A magnetometer based payload for a PTOL UAV with application in geophysical surveys

Includes bibliographical references.Applying the principles of physics to studying the Earth has given rise to the field of geophysics, which has been recognised as a separate discipline since the 19th century. The practical implementation of this field has led to a separate branch, aptly named exploration geophysics. Exploration geophysics aims to measure various naturally occurring phenomena associated with the Earth in order to make predictions about what might lie beneath the Earth’s surface. One of the fundamental phenomena associated with the Earth is the magnetic field or geomagnetic field. By localising magnetic anomalies within the geomagnetic field one can make predictions or inferences about the localised geophysical makeup and potential ore bodies, hydrocarbon deposits or archaeological artefacts that might exist below the surface. The fundamental sensor used to perform these surveys is the magnetometer. The concept of an unmanned aerial vehicle (UAV) has been around since 1915, with the first manufactured UAV appearing in 1916. Subsequent to the realisation of the UAV in the 1950s by Ryan Aeronautical for military reconnaissance, the idea of using UAV platforms to perform dull, dirty and dangerous functions has become common-place in the military environment. The first practical use of a UAV came in the 1991 Gulf War. The subsequent appearance of UAVs in the civilian realm can largely be attributed to the advent of low cost, high power density, lithium based batteries in the 1990s and the growth of the radio controlled (RC) hobbyist market

Testing the Production of Scintillation Arcs with the Pulsar B1133+16

Pulsars are extremely dense, highly magnetized stars that emit pulses of radio emission every millisecond or so. The arrival times of their radio signals at Earth observatories can be used as a clock precise enough to detect gravitational waves. Performing such a detection requires the mitigation of interference effects from the interstellar medium: the slightly ionized, mostly hydrogen gas that the radio waves traverse as they travel from the pulsar to Earth. We investigate radio wave delays using a powerful tool: scintillation arcs, fluctuations in frequency and time of the pulsar signal intensity that are manifested as parabolic arcs in the pulsar’s secondary spectrum. While scintillation arcs were first observed by Oberlin students almost two decades ago, the structures that cause them are still unknown. We explore the unique capabilities of the pulsar B1133+16 for testing models of scintillation arcs. Using measurements of scintillation arc curvatures over 96 days, we test a model for the annual modulation of arc curvature due to Earth’s orbit. The formalism for determining the width of a pulsar image from a scintillation arc width is used to design an empirical test of scintillation arc models based on the frequency dependence of arc widths. This formalism is then explored in the framework of a simple, one-dimensional model for the production of scintillation arcs

Balancing Power Auctions - Theoretical and Empirical Analyses

The European-wide goal of increasing the share of final electricity consumption from renewable sources to 27% by 2030 increases the supply volatility of the power system considerably. To manage this volatility, ancillary services for the power system become increasingly important. The most important short-term ancillary service is balancing power: it balances the electricity demand and supply instantaneously and, thus, ensures a constant frequency over time in alternating current grids. In most liberalized electricity markets worldwide, the procurement of balancing power is organized with the help of auctions. This thesis analyzes balancing power auctions theoretically and empirically and focuses on the current Austrian-German and the future European-wide Secondary Balancing Power (aFRR) auction design

Context-Dependent Memory and Chewing Gum

Context-dependent memory refers to improved recall of specific episodes or information when the context present at encoding and retrieval are the same. The effects that chewing gum has on memory during the encoding phase have been studied many times with contrasting results. Some studies show evidence that chewing gum while encoding and during recall may improve performance and other studies show no effect. The current study sought to replicate and extend previous research. Results showed no support for the context-dependent memory phenomenon