364 research outputs found
A Precision Calculation of the Next-to-Leading Order Energy-Energy Correlation Function
The O(alpha_s^2) contribution to the Energy-Energy Correlation function (EEC)
of e+e- -> hadrons is calculated to high precision and the results are shown to
be larger than previously reported. The consistency with the leading logarithm
approximation and the accurate cancellation of infrared singularities exhibited
by the new calculation suggest that it is reliable. We offer evidence that the
source of the disagreement with previous results lies in the regulation of
double singularities.Comment: 6 pages, uuencoded LaTeX and one eps figure appended Complete paper
as PostScript file (125 kB) available at:
http://www.phys.washington.edu/~clay/eecpaper1/paper.htm
Diamond: The Game â a board game for secondary school students promoting scientific careers and experiences
Diamond: The Game is a board game designed for secondary school students (aged 11â18) to enable them to explore a broad variety of science, technology, engineering and mathematics (STEM) careers, STEM subjects and life as a scientist. Board games are a reusable and entertaining way to directly engage students in STEM, but careful consideration of mechanics, messages and accessibility is required to successfully deliver on this goal. Diamond: The Game was designed and evaluated against these considerations. The inclusive approach to design resulted in a better and more accessible game for all. Its success is further evident in the rise in the number of players who would consider a career as a scientist or an engineer after playing. The opportunities to explore collaboration, failure and the interdisciplinary nature of science in the game were particularly highlighted in discussions with students, teachers and careers advisers
Effects of Color Attributes on Trap Capture Rates of Chrysobothris femorata (Coleoptera: Buprestidae) and Related Species
Chrysobothris spp. (Coleoptera: Buprestidae) and other closely related buprestids are common pests of fruit, shade, and nut trees in the United States. Many Chrysobothris spp., including Chrysobothris femorata, are polyphagous herbivores. Their wide host range leads to the destruction of numerous tree species in nurseries and orchards. Although problems caused by Chrysobothris are well known, there are no reliable monitoring methods to estimate local populations before substantial damage occurs. Other buprestid populations have been effectively estimated using colored sticky traps to capture beetles. However, the attraction of Chrysobothris to specific color attributes has not been directly assessed. A multi-color trapping system was utilized to determine color attraction of Chrysobothris spp. Specific color attributes (lightness [L*], red to green [a*], blue to yellow [b*], chroma [C*], hue [h*], and peak reflectance [PR]) were then evaluated to determine beetle responses. In initial experiments with mostly primary colors, Chrysobothris were most attracted to traps with red coloration. Thus, additional experiments were performed using a range of trap colors with red reflectance values. Among these red reflectance colors, it was determined that the violet range of the electromagnetic spectrum had greater attractance to Chrysobothris. Additionally, Chrysobothris attraction correlated with hue and b*, suggesting a preference for traps with hues between red to blue. However, males and females of some Chrysobothris species showed differentiated responses. These findings provide information on visual stimulants that can be used in Chrysobothris trapping and management. Furthermore, this information can be used in conjunction with ecological theory to understand host-location methods of Chrysobothris
Causality constraints in AdS/CFT from conformal collider physics and Gauss-Bonnet gravity
We explore the relation between positivity of the energy constraints in
conformal field theories and causality in their dual gravity description. Our
discussion involves CFTs with different central charges whose description, in
the gravity side, requires the inclusion of quadratic curvature corrections. It
is enough, indeed, to consider the Gauss-Bonnet term. We find that both sides
of the AdS/CFT correspondence impose a restriction on the Gauss-Bonnet
coupling. In the case of 6d supersymmetric CFTs, we show the full matching of
these restrictions. We perform this computation in two ways. First by
considering a thermal setup in a black hole background. Second by scrutinizing
the scattering of gravitons with a shock wave in AdS. The different helicities
provide the corresponding lower and upper bounds. We generalize these results
to arbitrary higher dimensions and comment on some hints and puzzles they
prompt regarding the possible existence of higher dimensional CFTs and the
extent to which the AdS/CFT correspondence would be valid for them.Comment: 31 pages, 5 figures; v2: typos fixed, cosmetic amendments and
references adde
The agency of liminality: army wives in the DR Congo and the tactical reversal of militarization
The inherently unstable boundaries between military and civilian worlds have emerged as a main object of study within the field of critical military studies. This article sheds light on the (re)production of these boundaries by attending to a group that rarely features in the debates on the military/civilian divide: army wives in a ânon-Northernâ context, more specifically the Democratic Republic of the Congo (DRC). Drawing upon the âanalytical toolboxâ of governmentality, we explore how civilian and military positionalities are called upon, articulated and subverted in the governing and self-governing of Congolese army wives. We show the decisive importance of these wivesâ civilian-military âin betweennessâ both in efforts to govern them and in their exercise of agency, in particular
The inherently unstable boundaries between military and civilian worlds have emerged as a main object of study within the field of critical military studies. This article sheds light on the (re)production of these boundaries by attending to a group that rarely features in the debates on the military/civilian divide: army wives in a ânon-Northernâ context, more specifically the Democratic Republic of the Congo (DRC). Drawing upon the âanalytical toolboxâ of governmentality, we explore how civilian and military positionalities are called upon, articulated, and subverted in the governing and self-governing of Congolese army wives. We show the decisive importance of these wivesâ civilianâmilitary âin-betweennessâ both in efforts to govern them and in their exercise of agency, in particular the ways in which they âtactically reverseâ militarization. The article also demonstrates the dispersed nature of the governing arrangements surrounding army wives, highlighting the vital role of âthe civilianâ as well as the âagency of those being militarizedâ within processes of militarization. By foregrounding the relevance of studying Congolese army wives and their militarization with an analytical toolbox often reserved for so called âadvanced militaries/societiesâ, and by revealing numerous similarities between the Congolese and âNorthernâ contexts, the article also sets out to counter the Euro/US-centrism and âtheoretical discriminationâ that mark present-day (critical) military studies
Doing military fitness: physical culture, civilian leisure, and militarism
Drawing explicitly upon the bodily techniques of military basic training and the corporeal competencies of ex-military personnel, military-themed fitness classes and physical challenges have become an increasingly popular civilian leisure pursuit in the UK over the last two decades. This paper explores the embodied regimes, experiences, and interactions between civilians and ex-military personnel that occur in these emergent hybrid leisure spaces. Drawing on ethnographic data, I argue that commercial military fitness involves a repurposing and rearticulation of collective military discipline within a late modern physical culture that emphasizes the individual body as a site of self-discovery and personal responsibility. Military fitness is thus a site of a particular biopolitics, of feeling alive in a very specific way. The intensities and feelings of physical achievement and togetherness that are generated emerge filtered through a particular military lens, circulating around and clinging to the totem of the repurposed ex-martial body. In the commercial logic of the fitness market, being âmilitaryâ and the ex-soldierâs body have thus become particularly trusted and affectively resonant brands
Solidification of Al alloys under electromagnetic pulses and characterization of the 3D microstructures under synchrotron x-ray tomography
A novel programmable electromagnetic pulse device was developed and used to study the solidification of Al-15 pct Cu and Al-35 pct Cu alloys. The pulsed magnetic fluxes and Lorentz forces generated inside the solidifying melts were simulated using finite element methods, and their effects on the solidification microstructures were characterized using electron microscopy and synchrotron X-ray tomography. Using a discharging voltage of 120 V, a pulsed magnetic field with the peak Lorentz force of ~1.6 N was generated inside the solidifying Al-Cu melts which were showed sufficiently enough to disrupt the growth of the primary Al dendrites and the Al2Cu intermetallic phases. The microstructures exhibit a strong correlation to the characteristics of the applied pulse, forming a periodical pattern that resonates the frequency of the applied electromagnetic field
Optimizing for periodicity: a model-independent approach to flux crosstalk calibration for superconducting circuits
Flux tunability is an important engineering resource for superconducting
circuits. Large-scale quantum computers based on flux-tunable superconducting
circuits face the problem of flux crosstalk, which needs to be accurately
calibrated to realize high-fidelity quantum operations. Typical calibration
methods either assume that circuit elements can be effectively decoupled and
simple models can be applied, or require a large amount of data. Such methods
become ineffective as the system size increases and circuit interactions become
stronger. Here we propose a new method for calibrating flux crosstalk, which is
independent of the underlying circuit model. Using the fundamental property
that superconducting circuits respond periodically to external fluxes,
crosstalk calibration of N flux channels can be treated as N independent
optimization problems, with the objective functions being the periodicity of a
measured signal depending on the compensation parameters. We demonstrate this
method on a small-scale quantum annealing circuit based on superconducting flux
qubits, achieving comparable accuracy with previous methods. We also show that
the objective function usually has a nearly convex landscape, allowing
efficient optimization
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