60,474 research outputs found
[Review of] Roy Harvey Pearce. Savagism and Civilization: A Study of the Indian and the American Mind. Rev. ed. of The Savages of America
This classic volume on the image of the Indian in the American mind first appeared in 1953. Although both limited and incomplete, Pearce\u27s work compelled a virtual revolution in literary and historical approaches to analysis of public view concerning the role of Indians in the American past
Techniques for controlling warpage and residual stresses in welded structures
Thermal pattern alteration technique controls both distortion and residual stresses in aluminum weldments. Cryogenic liquids and auxiliary heat sources are used to produce contraction and expansion of metal in the vicinity of the weld in such a manner as to counterbalance expansion and contraction caused by welding
Development of an undergraduate multidisciplinary engineering project
During their time at university it is necessary for undergraduate engineering students to develop not just technical skills related to their chosen engineering subject, but to also develop team working, time management, self organisation and decision making skills that will enable them to work effectively as engineers in the real world after graduation. These important transferable skills are highly sought after by industry and any chance to identify where such skills have been successfully used during an undergraduate degree course is a valuable addition to a student’s CV when subsequently entering the job market. To address the need of developing transferable skills, the School of Engineering and Design Multidisciplinary Project (MDP) was introduced in 2007 to provide first year undergraduate students with an opportunity to work together in multidisciplinary teams on a design and construction project. Each team is comprised of students from across the range of subject areas within the School and tasked with designing and building a robotic vehicle to tackle an obstacle course. The basis for the kits provided to each team are Lego Mindstorms robots for a majority of groups while the remaining groups are provided with a Parallax Basic STAMP 2 chip and a micro-controller chip to design their vehicle around. Figure 1 shows a selection of the 50 completed project builds from the 2009 MDP, showing the wide array of designs produced by the students. This paper describes the main aims of the MDP and gives an overview of how it has developed over the last three years to become a key part of the engineering undergraduate programme at Brunel University
Effects of opposing voltage and magnetic fields on charged particle motion
The motion of charged particles was examined in the case of a homogeneous magnetic field together with an orthogonal electric field which has a gradient opposing voltage parallel to the electric field. Two regimes result: in one of these, the particles' rate of gyration is changed from the conventional gyrofrequency; in the other, acceleration of the particle takes place. Applied to a plasma, the theory predicts new electric currents orthogonal to magnetic fields
Coulomb collisions of ring current particles: Indirect source of heat for the ionosphere
The additional energy requirements of the topside ionosphere during a magnetic storm are less than one quarter of the ring current energy. This energy is supplied largely by Coulomb collisions of ring current protons of energy less than about 20 keV with background thermal electrons which conduct the heat to the ionosphere. Past criticisms are discussed of this mechanism for the supply of energy to the SAR-arc and neighboring regions of the ionosphere
Against Citizenship as a Predicate for Basic Rights
The subject of my remarks will be citizenship, or more precisely the lack thereof, as a wedge issue on matters of rights, the rule of law, and the war on terror. I will argue that we ought to be careful about relying on citizenship as a rallying call for rights and protections precisely because the distinction between citizenship and its lack has proven to be such a tempting avenue for illegitimate trade-offs between liberty and security
The evolution of electron density and temperature distributions in the topside ionosphere during magnetic storms
The latitudinal distributions of electron density and temperature during geomagnetic storms in the mid-latitude topside ionosphere are observed to change in a manner than can be related to the evolution of ring current particle populations. The region of auroral precipitation is characterized by correlated increases in electron temperature and density. Equatorwards of this region, there is a broad belt of elevated electron temperatures and depressed electron densities which is usually much broader than any stable auroral red arc distinguishable from the ground, but which is nevertheless the same basic physical phenomenon. The changes of position of this belt can be related to prior bursts of geomagnetic activity and injection of ring current particles into the magnetosphere
Effects of large induced superconducting gap on semiconductor Majorana nanowires
With the recent achievement of extremely high-quality epitaxial interfaces
between InAs nanowires and superconducting Al shells with strong
superconductor-semiconductor tunnel coupling, a new regime of proximity-induced
superconductivity in semiconductors can be explored where the induced gap may
be similar in value to the bulk Al gap (large gap) with negligible subgap
conductance (hard gap). We propose several experimentally relevant consequences
of this large-gap strong-coupling regime for tunneling experiments, and we
comment on the prospects of this regime for topological superconductivity. In
particular, we show that the advantages of having a strong spin-orbit coupling
and a large spin g-factor in the semiconductor nanowire may both be compromised
in this strongly coupled limit, and somewhat weaker interface tunneling may be
necessary for achieving optimal proximity superconductivity in the
semiconductor nanowire. We derive a minimal, generic theory for the
strong-coupling hard-gap regime obtaining good qualitative agreement with the
experiment and pointing out future directions for further progress toward
Majorana nanowires in hybrid semiconductor-superconductor structures.Comment: 8 pages, 5 figures; published versio
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