1,833 research outputs found

    Broadband infrared meanderline reflective quarter-wave plate

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    We present a novel reflective quarter-wave plate comprised of subwavelength meanderline elements. The device is operational over the long-wave infrared (LWIR) spectrum, with significant spectral and angular bandwidths. Power reflection is approximately 70% over the majority of the LWIR. Efficient conversion from a 45 linear polarization state into circular polarization is demonstrated from finite-element electromagnetic simulations and from broadband polarimetric measurements

    Broadband circularly-polarized infrared emission from multilayer metamaterials

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    Development of a 2D metamaterial that preferentially emits broadband circularly-polarized (CP) infrared radiation is hindered by the fact that orthogonal electric-field components are uncorrelated at the surface of the thermal emitter, a consequence of the fluctuation-dissipation theorem. We achieve broadband CP thermal emission by fabricating a meanderline quarter-wave retarder on a transparent thermal-isolation layer. Behind this isolation layer, in thermal contact with the emitter, is a wire-grid polarizer. Along with an unavoidable linear polarized radiation characteristic from the meanderline, we measured a degree of circular polarization (DOCP) of 28%, averaged over the 8- to 12 mu m band

    Movement and Countermovement Dynamics Between the Religious Right and LGB Community Arising from Colorado’s Amendment 2

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    This sample of the case study of Equality Colorado will demonstrate how counter movements and litigation may limit and change how an organization surrounding a social movement acts. Colorado for Family Values helped pass Colorado’s Amendment 2 in 1992, which limited any present and future anti-discrimination legislation that would protect sexuality as a class. This ballot initiative passed by 53% of Colorado voters, and other states like Idaho and Oregon attempted to replicate this type of initiative. Amendment 2 challenged the LGB community and compelled the movement to collectively respond to the religious right with coalitions, pooled resources, and litigation. Equality Colorado, established in 1992, will exemplify how a social movement could respond to prejudicial legislation. One of Equality Colorado’s primary tactics was to reframe religion as inclusive of gay rights. It did not cede religion entirely to its opponents and attempted to delegitimize them by labeling them “radical right” as opposed to the more popular term “religious right” or “Christian Conservatives”. Additionally, Equality Colorado tried to compensate for the downsides of litigation by “translating” the legal terms to the general public and connecting litigators with the broader movement

    Maximal Sharing in the Lambda Calculus with letrec

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    Increasing sharing in programs is desirable to compactify the code, and to avoid duplication of reduction work at run-time, thereby speeding up execution. We show how a maximal degree of sharing can be obtained for programs expressed as terms in the lambda calculus with letrec. We introduce a notion of `maximal compactness' for lambda-letrec-terms among all terms with the same infinite unfolding. Instead of defined purely syntactically, this notion is based on a graph semantics. lambda-letrec-terms are interpreted as first-order term graphs so that unfolding equivalence between terms is preserved and reflected through bisimilarity of the term graph interpretations. Compactness of the term graphs can then be compared via functional bisimulation. We describe practical and efficient methods for the following two problems: transforming a lambda-letrec-term into a maximally compact form; and deciding whether two lambda-letrec-terms are unfolding-equivalent. The transformation of a lambda-letrec-term LL into maximally compact form L0L_0 proceeds in three steps: (i) translate L into its term graph G=[[L]]G = [[ L ]]; (ii) compute the maximally shared form of GG as its bisimulation collapse G0G_0; (iii) read back a lambda-letrec-term L0L_0 from the term graph G0G_0 with the property [[L0]]=G0[[ L_0 ]] = G_0. This guarantees that L0L_0 and LL have the same unfolding, and that L0L_0 exhibits maximal sharing. The procedure for deciding whether two given lambda-letrec-terms L1L_1 and L2L_2 are unfolding-equivalent computes their term graph interpretations [[L1]][[ L_1 ]] and [[L2]][[ L_2 ]], and checks whether these term graphs are bisimilar. For illustration, we also provide a readily usable implementation.Comment: 18 pages, plus 19 pages appendi

    Very high rotational frequencies and band termination in 73Br

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    Rotational bands in 73Br have been investigated up to spins of 65/2 using the EUROBALL III spectrometer. One of the negative-parity bands displays the highest rotational frequency 1.85 MeV reported to date in nuclei with mass number greater than 25. At high frequencies, the experimental dynamic moment of inertia for all bands decrease to very low values, indicating a loss of collectivity. The bands are described in the configuration-dependent cranked Nilsson-Strutinsky model. The calculations indicate that one of the negative-parity bands is observed up to its terminating single-particle state at spin 63/2. This result establishes the first band termination case in the A = 70 mass region.Comment: 6 pages, 6 figures, submitted to Phys. Rev. C as a Rapid Communicatio

    Changes in drug use during ages 18-32

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    https://deepblue.lib.umich.edu/bitstream/2027.42/137887/1/occ39.pd

    Dynamics of microtubule depolymerization in monocytes.

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