Electromagnetic scattering and radiation from microstrip patch antennas and spirals residing in a cavity

A new hybrid method is presented for the analysis of the scattering and radiation by conformal antennas and arrays comprised of circular or rectangular elements. In addition, calculations for cavity-backed spiral antennas are given. The method employs a finite element formulation within the cavity and the boundary integral (exact boundary condition) for terminating the mesh. By virtue of the finite element discretization, the method has no restrictions on the geometry and composition of the cavity or its termination. Furthermore, because of the convolutional nature of the boundary integral and the inherent sparseness of the finite element matrix, the storage requirement is kept very low at O(n). These unique features of the method have already been exploited in other scattering applications and have permitted the analysis of large-size structures with remarkable efficiency. In this report, we describe the method's formulation and implementation for circular and rectangular patch antennas in different superstrate and substrate configurations which may also include the presence of lumped loads and resistive sheets/cards. Also, various modelling approaches are investigated and implemented for characterizing a variety of feed structures to permit the computation of the input impedance and radiation pattern. Many computational examples for rectangular and circular patch configurations are presented which demonstrate the method's versatility, modeling capability and accuracy

Solitons in finite droplets of noncommutative Maxwell-Chern-Simons theory

We find soliton solutions of the noncommutative Maxwell-Chern-Simons theory confined to a finite quantum Hall droplet. The solitons are exactly as hypothesized in \cite{Manu}. We also find new variations on these solitons. We compute their flux and their energies. The model we consider is directly related to the model proposed by Polychronakos\cite{Poly} and studied by Hellerman and Van Raamsdonk\cite{HvR} where it was shown that it is equivalent to the quantum Hall effect.Comment: 18 pages, 7 figures, minor corrections, version accepted for publication, this time really

Gauge Theory of the Star Product

The choice of a star product realization for noncommutative field theory can be regarded as a gauge choice in the space of all equivalent star products. With the goal of having a gauge invariant treatment, we develop tools, such as integration measures and covariant derivatives on this space. The covariant derivative can be expressed in terms of connections in the usual way giving rise to new degrees of freedom for noncommutative theories.Comment: 16 page

Dirac Operator on the Quantum Sphere

We construct a Dirac operator on the quantum sphere $S^2_q$ which is covariant under the action of $SU_q(2)$. It reduces to Watamuras' Dirac operator on the fuzzy sphere when $q\to 1$. We argue that our Dirac operator may be useful in constructing $SU_q(2)$ invariant field theories on $S^2_q$ following the Connes-Lott approach to noncommutative geometry.Comment: 13 page

Beyond the team: understanding interprofessional work in two North American ICUs

OBJECTIVE: To examine the ways in which healthcare professionals work together in the ICU setting, through a consideration of the contextual, organizational, processual, and relational factors that impact their interprofessional collaboration. DESIGN: Data from over 350 hours of ethnographic observation and 35 semistructured interviews with clinicians in two ICUs were collected by two medical anthropologists over a period of 6 months. SETTING: Medical surgical ICUs in two urban research hospitals in Canada and the United States. MAIN RESULTS: Although the concept of teamwork is often central to interventions to improve patient safety in the ICU, our observations suggest that this concept does not fully describe how interprofessional work actually occurs in this setting. With the exception of crisis situations, most interprofessional interactions in the two ICUs we studied could be better described as forms of interprofessional work other than teamwork, which include collaboration, coordination, and networking. CONCLUSIONS: A singular notion of team is too reductive to account for the ways in which work happens in the ICU and therefore cannot be taken for granted in quality improvement initiatives or among healthcare professionals in this setting. Adapting -interventions to the complex nature of interprofessional work and each ICUs unique local context is an important and necessary step to ensure the delivery of safe and effective patient care