3,584 research outputs found

    Millimeter-Waves Structures on Benzocyclobutene Dielectric Substrate

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    The need of low-loss substrate materials with stable dielectric performances is a strong requirement when working at millimeter frequencies, where standard dielectrics exhibit prohibitive losses. In this paper, the authors focus their attention on a polymer material, the benzocyclobutene (BCB), having a low dielectric constant and a low loss tangent, with a stable behavior up to THz frequencies. A specific in-house manufacture technology is described to realize millimeter-wave structures on a BCB dielectric substrate. Experimental validations on BCB-based circuits and antennas prototypes are discussed

    Beam position monitor

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    This report addresses the accelerator physics technical note no. 11

    Radar array diagnosis from undersampled data using a compressed sensing/sparse recovery technique

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    A Compressed Sensing/Sparse Recovery approach is adopted in this paper for the accurate diagnosis of fault array elements from undersampled data. Experimental validations on a slotted waveguide test array are discussed to demonstrate the effectiveness of the proposed procedure in the failures retrieval from a small set of measurements with respect to the number of radiating elements. Due to the sparsity feature of the proposed formulation, the method is particularly appealing for the diagnostics of large arrays, typically adopted for radar applications

    Tunable Reflectarray Cell for Wide Angle Beam-Steering Radar Applications

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    An electronically tunable reflectarray element is proposed in this work to design beam-steering antennas useful for radar applications. A reduced size reflectarray unit cell is properly synthesized in order to extend the antenna beam scanning capabilities within a wider angular region. The radiating structure is accurately optimized to provide a full phase tuning range by adopting a single varactor load as phase shifter element. A 0.46 -reflectarray cell is designed at the frequency of 11.5 GHz, obtaining a phase agility of about 330 ∘ . The cell is successfully adopted for the design of a 21 × 21 reconfigurable reflectarray. The antenna is numerically tested for different configurations of the varactors capacitance values, and good beam-steering performances are demonstrated within a wide angular range

    Big data managing in a landslide early warning system: Experience from a ground-based interferometric radar application

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    A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System): An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC), where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar) and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing

    Aberrant splicing and expression of the non muscle myosin heavy-chain gene MYH14 in DM1 muscle tissues

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    Myotonic dystrophy type 1 (DM1) is a complex multisystemic disorder caused by an expansion of a CTG repeat located at the 3' untranslated region (UTR) of DMPK on chromosome 19q13.3. Aberrant messenger RNA (mRNA) splicing of several genes has been reported to explain some of the symptoms of DM1 including insulin resistance, muscle wasting and myotonia. In this paper we analyzed the expression of the MYH14 mRNA and protein in the muscle of DM1 patients (n=12) with different expansion lengths and normal subjects (n=7). The MYH14 gene is located on chromosome 19q13.3 and encodes for one of the heavy chains of the so called class II "nonmuscle" myosins (NMHCII). MYH14 has two alternative spliced isoforms: the inserted isoform (NMHCII-C1) which includes 8 amino acids located in the globular head of the protein, not encoded by the non inserted isoform (NMHCII-C0). Results showed a splicing unbalance of the MYH14 gene in DM1 muscle, with a prevalent expression of the NMHCII-C0 isoform more marked in DM1 patients harboring large CTG expansions. Minigene assay indicated that levels of the MBNL1 protein positively regulates the inclusion of the MYH14 exon 6. Quantitative analysis of the MYH14 expression revealed a significant reduction in the DM1 muscle samples, both at mRNA and protein level. No differences were found between DM1 and controls in the skeletal muscle localization of MYH14, obtained through immunofluorescence analysis. In line with the thesis of an "RNA gain of function" hypothesis described for the CTG mutation, we conclude that the alterations of the MYH14 gene may contribute to the DM1 molecular pathogenesis

    Multiband Software Defined Radar for Soil Discontinuities Detection

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    A multiband Software Defined Radar based on orthogonal frequency-division multiplexing technique is proposed in this work for an accurate soil discontinuities detection, taking into account also the dispersive behavior of media. A multilayer soil structure is assumed as a validation test to demonstrate the effectiveness of the proposed approach, by accurately retrieving the unknown thicknesses and permittivities of the soil layers
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