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In this paper, we study the radiation from embedded sources in two-dimensional finite-size "photonic-quasicrystal" (PQC) slabs made of dielectric rods arranged according to a 12-fold symmetric aperiodic tiling. The results from our investigation, based on rigorous full-wave simulations, show the possibility of achieving broadside radiation at multiple frequencies, with high directivity (e.g., 15 dB) and low sidelobes (e.g., -12 dB). We also show that leaky waves are supported by a PQC slab and that the beamwidth is directly proportional to the leaky wave attenuation constant, which provides a physically incisive interpretation of the observed radiation characteristics. © 2009 The American Physical Society.

This letter deals with a study of aperiodically ordered textured (mushroom-type) high-impedance surfaces (HISs), and their possible application as artificial-magnetic-conductor groundplanes for low-profile directive antennas. In this framework, results from full-wave simulations are presented in order to characterize the electromagnetic response (in terms of impedance matching, directivity, and surface-wave suppression) of selected configurations based on representative categories of aperiodic tilings, and compare them with those of standard periodic HISs. © 2008 IEEE.

In this paper, we present a comparative study of the emission properties of line sources embedded in two-dimensional finite-size aperiodically-ordered "photonic-quasicrystal" slabs made of dielectric cylinders arranged according to representative categories of aperiodic tilings. Our study, based on a rigorous full-wave numerical method, indicates the possibility of achieving directive low-sidelobe emission at several frequencies. In this connection, parametric studies are presented, and similarities and differences with the periodic case are highlighted.

This paper deals with a study of textured (mushroom-type) high-impedance substrates based on aperiodic-tiling geometries. In this connection, preliminary results from full-wave simulations are presented in order to explore possible applications as artificial-magnetic-conductor ground-planes for low-profile directive antennas. © 2007 IEEE.

This letter is concerned with a comparative study of the electromagnetic properties of two-dimensional, finite-size, aperiodically ordered "quasi-crystal" dielectric structures based on representative categories of "aperiodic-tiling" geometries. In this framework, a rigorous full-wave solver is used to explore the electromagnetic bandgap and directive radiation properties of potential interest in antenna applications. © 2006 IEEE.

This letter is concerned with a comparative study of the electromagnetic properties of two-dimensional, finite-size, aperiodically ordered "quasi-crystal" dielectric structures based on representative categories of "aperiodic-tiling" geometries. In this framework, a rigorous full-wave solver is used to explore the electromagnetic bandgap and directive radiation properties of potential interest in antenna applications. © 2006 IEEE.

This Letter presents a study of the local density of states (LDOS) in photonic quasicrystals. We show that the LDOS of a Penrose-type quasicrystal exhibits small additional band gaps. Among the band gaps, some exhibit a behavior similar to that typical of photonic crystals, while others do not. The development of certain band gaps requires large-size quasicrystals. It is explained by the long-range interactions involved in their formation. Moreover, the frequencies where the band gaps occur are not necessarily explained using single scattering and should therefore involve multiple scattering.

Background: General physicians play a significant role in the health management of crises. In order to enhance the knowledge and skills of medical students on how to address health-related issues in crises and to promote their ability to manage and deal with such crises after graduation, appropriate training is necessary. Methods: Applying the Delphi method, 103 experts with field experience in health management and crises were invited to participate in the study. The Delphi study provided aggregation of the opinions and extracted the topics. Conventional content analysis was used to make sense of qualitative data gathered during the study. Results: Among the feedback (n = 66) obtained in the first round, a primary list was extracted including 27 topics and 97 single items. Nineteen major topics, encompassing 97 items, were finally determined in the subsequent rounds. The participants agreed to teach this course at the beginning the internship period via different methods of instruction. Conclusion: This study indicated that health management in crises is important and must be taught in medicine. This study provided a blueprint and an educational rationale as well as contents and structure of a course on health management in crisis to be delivered in undergraduate medical education.