1,921 research outputs found

    Strongly birefringent cut-wire pair structure as negative index wave plates at THz frequencies

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    We report a new approach for the design and fabrication of thin wave plates with high transmission in the terahertz (THz) regime. The wave plates are based on strongly birefringent cut-wire pair metamaterials that exhibit refractive indices of opposite signs for two orthogonal polarization components of an incident wave. As specific examples, we fabricated and investigated a quarter- and a half-wave plate that revealed a peak intensity transmittance of 74% and 58% at 1.34 THz and 1.3 THz, respectively. Furthermore, the half wave plate displayed a maximum figure of merit (FOM) of 23 at 1.3 THz where the refractive index was -1.7. This corresponds to one of the highest FOMs reported at THz frequencies so far. The presented results evidence that negative index materials enter an application stage in terms of optical components for the THz technology.Comment: 4 pages, 3 figures, submitted to Appl. Phys. Let

    Do not attempt resuscitation : the importance of consensual decisions

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    Aims: To describe the involvement and input of physicians and nurses in cardiopulmonary resuscitation (cpr / do not attempt resuscitation (dnar) decisions; to analyse decision patterns; and understand the practical implications. Design: A qualitative grounded theory study using one-time open-ended interviews with 40 volunteer physicians and 52 nurses drawn from acute care wards with mixes of heterogeneous cases in seven different hospitals in German-speaking Switzerland. Results: Establishing dnar orders in the best interests of patients was described as a challenging task requiring the leadership of senior physicians and nurses. Implicit decisions in favour of cpr predominated at the beginning of hospitalisation; depending on the context, they were relieved/superseded by explicit dnar decisions. Explicit decisions were the result of hierarchical medical expertise, of multilateral interdisciplinary expertise, of patient autonomy and/or of negotiated patient autonomy. Each type of decision, implicit or explicit, potentially represented a team consensus. Non-consensual decisions were prone to precipitate personal or team conflicts, and, occasionally, led to non-compliance. Conclusion: Establishing dnar orders is a demanding task. Reaching a consensus is of crucial importance in guaranteeing teamwork and good patient care. Communication and negotiation skills, professional and personal life experience and empathy for patients and colleagues are pivotal. Therefore, leadership by experienced senior physicians and nurses is needed and great efforts should be made with regard to multidisciplinary education

    Зі щоденникових записів М.С.Баликіна

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    We have used phase-sensitive ultrashort-pulse interferometry to study the modification of optical pulse propagation near the photonic band edges in colloidal crystals consisting of polystyrene spheres in water. A strong suppression of the group velocity is found at frequencies near the L gap of the fcc lattice. The group velocity dispersion diverges at the band edges and shows branches of both normal dispersion and anomalous dispersion, which can be interpreted as large changes in the effective mass, both positive and negative. We obtain excellent agreement with the dynamical diffraction theory

    System Reliability Evaluation Using Concurrent Multi-Level Simulation of Structural Faults

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    This paper provides a methodology that leverages state-of-the-art techniques for efficient fault simulation of structural faults together with transaction level modeling. This way it is possible to accurately evaluate the impact of the faults on the entire hardware/software syste

    The ARGUS Vertex Trigger

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    A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5\,mm radius.Comment: gzipped Postscript, 27 page

    Efficient Simulation of Structural Faults for the Reliability Evaluation at System-Level

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    In recent technology nodes, reliability is considered a part of the standard design ¿ow at all levels of embedded system design. While techniques that use only low-level models at gate- and register transfer-level offer high accuracy, they are too inefficient to consider the overall application of the embedded system. Multi-level models with high abstraction are essential to efficiently evaluate the impact of physical defects on the system. This paper provides a methodology that leverages state-of-the-art techniques for efficient fault simulation of structural faults together with transaction-level modeling. This way it is possible to accurately evaluate the impact of the faults on the entire hardware/software system. A case study of a system consisting of hardware and software for image compression and data encryption is presented and the method is compared to a standard gate/RT mixed-level approac

    Assessing symmetry of financial returns series

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    Testing symmetry of a probability distribution is a common question arising from applications in several fields. Particularly, in the study of observables used in the analysis of stock market index variations, the question of symmetry has not been fully investigated by means of statistical procedures. In this work a distribution-free test statistic Tn for testing symmetry, derived by Einmahl and McKeague, based on the empirical likelihood approach, is used to address the study of symmetry of financial returns. The asymptotic points of the test statistic Tn are also calculated and a procedure for assessing symmetry for the analysis of the returns of stock market indices is presented.Comment: Econophysics paper. 6 pages 2 figure

    Efficacy, safety, and tolerance of piperacillin/tazobactam compared to co-amoxiclav plus an aminoglycoside in the treatment of severe pneumonia

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    An open, randomized, multicenter study was conducted to compare the efficacy and safety of piperacillin/tazobactam and co-amoxiclav plus aminoglycoside in the treatment of hospitalized patients with severe community-acquired or nosocomial pneumonia. Of the 89 patients who entered the study, 84 (94%) were clinically evaluable. A favorable clinical response was observed in 90% of the piperacillin/ tazobactam group and in 84% of the co-amoxiclav/aminoglycoside group (not significant). The bacteriological efficacy was comparable in both groups (96% vs. 92%; not significant). There was only one fatal outcome in the piperacillin/tazobactam group compared to six in the co-amoxiclav/aminoglycoside group regimenP=0.058). The adverse event rate was non-significantly lower in the piperacillin/ tazobactam group compared to the co-amoxiclav/aminoglycoside group (2% vs. 7%;P=0.32). Piperacillin/tazobactam is safe and highly efficacious in the treatment of serious pneumonia in hospitalized patients. It compares favorably with the combination of co-amoxiclav/aminoglycosid
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