732 research outputs found

    Time domain synthesis of pulsed arrays

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    Pulsed arrays are becoming popular in new ultrawideband applications to enhance the robustness of transmitted and received signals in complex environments and to identify the angle of arrival of multiple echoes. A global synthesis technique is here proposed to shape the array field in accordance to given angle-time constraints. The synthesis problem is cast as the inverse Radon transform of a desired array mask, applying the alternate projections method to include constraints over the input signals' waveform and to improve the synthesis robustness. The unknown array currents are generated as linear combinations of Hermite-Rodriguez functions in order to achieve a simple and realizable beamforming network. The effectiveness of the method is demonstrated by many examples

    Generation of Antibunched Light by Excited Molecules in a Microcavity Trap

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    The active microcavity is adopted as an efficient source of non-classical light. By this device, excited by a mode-locked laser at a rate of 100 MHz, single-photons are generated over a single field mode with a nonclassical sub-poissonian distribution. The process of adiabatic recycling within a multi-step Franck-Condon molecular optical-pumping mechanism, characterized in our case by a quantum efficiency very close to one, implies a pump self-regularization process leading to a striking n-squeezing effect. By a replication of the basic single-atom excitation process a beam of quantum photon (Fock states) can be created. The new process represents a significant advance in the modern fields of basic quantum-mechanical investigation, quantum communication and quantum cryptography

    CNT-based RFID passive gas sensor

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    Tattoo Antenna Temporary Transfers Operating On-Skin (TATTOOS)

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    This paper discusses the development of RFID logo antennas based on the logos of Loughborough University and the University of Kent which can be tattooed directly onto the skin’s surface. Hence, this paper uses aesthetic principles to create functional wearable technology. Simulations of possible designs for the tattoo tags have been carried out to optimize their performance. Prototypes of the tag designs were fabricated and read range measurements with the transfer tattoos on a volunteers arm were carried out to test the performance. Measured Read ranges of approximately 0.5 m have been achieved with the antenna 10 µm from the body

    Endovascular treatment of aortoesophageal and aortobronchial fistulae

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    none6Background: Even when promptly recognized and treated, aortoesophageal (AEF) and aortobronchial (ABF) fistulae are highly lethal conditions. Open surgical repair also carries a high risk of mortality and morbidity. Several alternative strategies have been recently reported in the literature including thoracic endovascular aortic repair (TEVAR). However, relatively little is known about results of TEVAR for AEF and ABF due to their rarity and the lack of large surveys. Methods: A voluntary national survey was conducted among Italian universities and hospital centers with an endovascular program. Questionnaires were distributed by e-mail to participating centers and aimed to evaluate the results of endovascular repair of established AEF or ABF. Results: Seventeen centers agreed to participate and provided data on their patients. Between 1998 and 2008, a total of 1138 patients were treated with TEVAR. In 25 patients (2.2%), the indication to treatment was an AEF and/or an ABF. In 10 of these cases (40%), an associated open surgical procedure was also performed. Thirty-day mortality rate of AEF/ABF endovascular repair was 28% (7 cases). No cases of paraplegia or stroke were observed. Mean follow-up was 22.6 months (range, 1-62). Actuarial survival at 2 years was 55%. Among the 18 initial survivors, five patients (28%) underwent reintervention due to late TEVAR failure. Conclusions: Stent grafting for AEF and ABF represents a viable option in emergent and urgent settings. However, further esophageal or bronchial repair is necessary in most cases. Despite less invasive attempts, mortality associated with these conditions remains very high. Copyright © 2010 by the Society for Vascular Surgery.Chiesa, R.; Melissano, G.; Marone, E.M.; Kahlberg, A.; Marrocco-Trischitta, M.M.; Tshomba, Y.Chiesa, R.; Melissano, G.; Marone, ENRICO MARIA; Kahlberg, A.; Marrocco Trischitta, M. M.; Tshomba, Y

    Physical activity self-management interventions for adults with spinal cord injury: Part 1–A systematic review of the use and effectiveness of behavior change techniques

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    Objectives: To determine which behavior change techniques (BCTs) have been used within leisure time physical activity (LTPA) self-management interventions for persons with spinal cord injury (SCI), and which BCTs were effective for improving LTPA behavior and/or its antecedents. Design: Systematic review informed by the PRISMA guidelines. Methods: A comprehensive literature search was conducted using five databases. Study characteristics were extracted from included articles and intervention descriptions were coded using the BCT Taxonomy V.1. Effectiveness and maintenance of BCTs as well as the level of behavior change theory use in the design of interventions were examined within experimental studies. Results: Thirty-one unique studies were included, 16 of which had an experimental design. Across all 31 studies, a total of 222 BCTs were identified, representing 32 out of a possible 93 BCTs. The most commonly used BCTs related to the core components of self-management (i.e., education, training/rehearsal of psychological strategies, and social support). Examination of the 16 experimental studies revealed that the use of BCTs corresponding to core self-management components were related to significant improvements and maintenance of LTPA outcomes, regardless of the number of BCTs used. Conclusions: This review offers a glimpse into the mechanisms by which self-management interventions lead to behavior change; however, more research is needed to explore and evaluate other elements (e.g., theory use, tailoring, dose, mode of delivery, and provider) that may comprise effective LTPA self-management interventions for persons with SCI. PROSPERO registration number: CRD42016037531
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