5,949 research outputs found
Metallized polymeric foam material
Open-celled polyurethane foams can be coated uniformly with thin film of metal by vapor deposition of aluminum or by sensitization of foam followed by electroless deposition of nickel or copper. Foam can be further processed to increase thickness of metal overcoat to impart rigidity or to provide inert surface with only modest increase in weight
Cavity QED with Multiple Hyperfine Levels
We calculate the weak-driving transmission of a linearly polarized cavity
mode strongly coupled to the D2 transition of a single Cesium atom. Results are
relevant to future experiments with microtoroid cavities, where the
single-photon Rabi frequency g exceeds the excited-state hyperfine splittings,
and photonic bandgap resonators, where g is greater than both the excited- and
ground-state splitting.Comment: 6 pages, 10 figure
Task-driven programming pedagogy in the digital humanities
In this chapter, we advocate for a task-driven approach to teaching computer programming to students of the digital humanities (DH). Our perspective is grounded first in Birnbaum's (2014) plenary address to the University of Pittsburgh Faculty Senate (Birnbaum 2014), in which he argued that coding, like writing, should be taught across the liberal arts curriculum in domain-appropriate ways. This position argued that (1) coding is not an esoteric specialization to be taught solely by computer scientists, and that (2) coding might be taught most effectively in the context of different disciplines. Here, we present a method for embedding Digital Humanities education, and more specifically programming pedagogy, within the long-standing traditions of the Humanities and argue that this approach works most effectively when new learners have access to context-specific mentorship. Our second point of reference lies with oral-proficiency-oriented (OP) foreign language pedagogy. Within an OP model, the ability to communicate in a foreign language is a skill, and the primary goal for learners who seek to acquire that skill is not an academic understanding of the grammar of a language, but, instead, the ability to function successfully within realistic contextualized human interactions. Seen from this perspective, computer-programming curricula organized around the features of the programming language might be compared to older grammar-and-translation foreign-language pedagogies. What we advocate instead is that the ability to use a programming language (programming proficiency) is best acquired in the context of performing contextualized, discipline-conscious tasks that are meaningful to humanists, an approach that has parallels to OP language learning
Trapped atoms in cavity QED: coupling quantized light and matter
On the occasion of the hundredth anniversary of Albert Einstein's annus mirabilis, we reflect on the development and current state of research in cavity quantum electrodynamics in the optical domain. Cavity QED is a field which undeniably traces its origins to Einstein's seminal work on the statistical theory of light and the nature of its quantized interaction with matter. In this paper, we emphasize the development of techniques for the confinement of atoms strongly coupled to high-finesse resonators and the experiments which these techniques enable
Cavity QED with Single Atoms and Photons
Recent experimental advances in the field of cavity quantum electrodynamics (QED) have opened new possibilities for control of atom-photon interactions. A laser with "one and the same atom" demonstrates the theory of laser operation pressed to its conceptual limit. The generation of single photons on demand and the realization of cavity QED with well defined atomic numbers N = 0, 1, 2,... both represent important steps toward realizing diverse protocols in quantum information science. Coherent manipulation of the atomic state via Raman transitions provides a new tool in cavity QED for in situ monitoring and control of the atom-cavity system. All of these achievements share a common point of departure: the regime of strong coupling. It is thus interesting to consider briefly the history of the strong coupling criterion in cavity QED and to trace out the path that research has taken in the pursuit of this goal
Excitation functions for (p,x) reactions of niobium in the energy range of E = 40-90 MeV
A stack of thin Nb foils was irradiated with the 100 MeV proton beam at Los
Alamos National Laboratory's Isotope Production Facility, to investigate the
Nb(p,4n)Mo nuclear reaction as a monitor for intermediate energy
proton experiments and to benchmark state-of-the-art reaction model codes. A
set of 38 measured cross sections for Nb(p,x) and
Cu(p,x) reactions between 40-90 MeV, as well as 5 independent
measurements of isomer branching ratios, are reported. These are useful in
medical and basic science radionuclide productions at intermediate energies.
The Cu(p,x)Co, Cu(p,x)Zn, and
Cu(p,x)Zn reactions were used to determine proton
fluence, and all activities were quantified using HPGe spectrometry. Variance
minimization techniques were employed to reduce systematic uncertainties in
proton energy and fluence, improving the reliability of these measurements. The
measured cross sections are shown to be in excellent agreement with literature
values, and have been measured with improved precision compared with previous
measurements. This work also reports the first measurement of the
Nb(p,x)Rb reaction, and of the independent cross
sections for Cu(p,x)Mn and
Nb(p,x)Y in the 40-90 MeV region. The effects of
Si(p,x)Na contamination, arising from silicone
adhesive in the Kapton tape used to encapsulate the aluminum monitor foils, is
also discussed as a cautionary note to future stacked-target cross section
measurements. \emph{A priori} predictions of the reaction modeling codes CoH,
EMPIRE, and TALYS are compared with experimentally measured values and used to
explore the differences between codes for the Nb(p,x) and
Cu(p,x) reactions.Comment: 34 pages, submitted to NIM-
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