368 research outputs found

    The heating of filaments as a disappearance process

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    The sudden disappearance of filaments, commonly called Disparition Brusque (DB) is of two types: (1) the well known ejection of cool prominence material in the corona, i.e., a dynamic process (BDd) and (2) the heating of the prominence plasma. When the hydrogen of the filament becomes ionised, then the filament start to be visible in EUV lines keeping the same shape and position as the cool one. This process which is a thermic disapperence was named DB thermic (DBt). Successive disappearances and condensations of a quiescent filament from 13 to 17 of June 1973 was studied. This observation was provided by two instruments on Skylab ATM satellite. These observations of disappearances and condensations are discussed

    Two-Dimensional Photonic Crystal Slab Nanocavities on Bulk Single-Crystal Diamond

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    Color centers in diamond are promising spin qubits for quantum computing and quantum networking. In photon-mediated entanglement distribution schemes, the efficiency of the optical interface ultimately determines the scalability of such systems. Nano-scale optical cavities coupled to emitters constitute a robust spin-photon interface that can increase spontaneous emission rates and photon extraction efficiencies. In this work, we introduce the fabrication of 2D photonic crystal slab nanocavities with high quality factors and cubic wavelength mode volumes -- directly in bulk diamond. This planar platform offers scalability and considerably expands the toolkit for classical and quantum nanophotonics in diamond

    Two-Tier Retaining Wall System to Support Railroad Embankment Widening

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    The National Railroad Passenger Corporation (Amtrak) is replacing the 1907-era two-track bascule bridge over the Niantic River between East Lyme and Waterford, Connecticut, along the heavily traveled Northeast Corridor. Prestressed concrete sheet pile retaining walls were selected to support the new higher approach embankments along both the east and west approaches to the new bridge. Along the west approach a two-tiered wall design was utilized to support a new recreational walkway elevated above the 100-year storm surge elevation for the Niantic Bay, while at the same time keeping the walkway below the level of the adjoining tracks. The design of the two-tier wall system needed to take into account two simultaneous Cooper E-80 train live loads, the influence of electric traction catenary structure foundations along the wall alignment, and live load surcharge from maintenance vehicles at the walkway level, while at the same time minimizing long-term impacts to the public beach. The concrete sheet pile wall was designed to support the upper prefabricated modular T-WALL® along with all imposed loads, while at the same time protecting the railroad embankment from the scour and wave action of a 100-year storm event in Long Island Sound, and taking into consideration challenging subsurface conditions

    Quantifying patient satisfaction with process metrics using a weighted bundle approach.

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    Background:Current patient satisfaction assessment results are delayed and obtained from select patient surveys. As a result, these assessments may not represent the experience of the entire patient population. This study developed a method to measure and evaluate all patients\u27 experiences while they are within the care episode and link it to processes within the organisation. Methods:Using the Six Sigma methodology, sites assembled diverse teams to categorise and analyse negative experience comments from patients to understand the drivers of dissatisfaction. These customer expectations lead to the development of the four components in the Patient Experience Bundle (PEB): communication, environment, basic needs/comfort and logistics. Individual process elements were ranked to create a numerical relationship between service and the needs expressed by the voice of the customer. Sites created surveys incorporating questions that focused on the bundle elements and measured daily bundle compliance. Graphical analysis and hypothesis testing enabled sites to determine key drivers of patient dissatisfaction within the bundle elements. Improvement strategies were developed and implemented to address the key drivers of patient dissatisfaction. Results:After implementing process improvements focused on issues identified by the PEB, bundle compliance improved from an average of 51% to an average of 82.5% and Press Ganey Likelihood to Recommend (PG LTR) scores improved from an average of 64.73% to an average 74.64%. The data demonstrated that the trends in improving PEB are followed by meaningful changes in PG LTR scores. Conclusion:This work is built on the identification of common elements of care that impact patient satisfaction and detailed mathematical analysis of the relationship between factors. Using the bundle concept, these improvement efforts maintain highly reliable processes to drive outcomes and provide real-time feedback on patient experience

    Comparison of the sidereal angular velocity of subphotospheric layers and small bright coronal structures during the declining phase of solar cycle 23

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    Context. We compare solar differential rotation of subphotospheric layers derived from local helioseismology analysis of GONG++ dopplergrams and the one derived from tracing small bright coronal structures (SBCS) using EIT/SOHO images for the period August 2001 - December 2006, which correspond to the declining phase of solar cycle 23. Aims. The study aims to find a relationship between the rotation of the SBCS and the subphotospheric angular velocity. The northsouth asymmetries of both rotation velocity measurements are also investigated. Methods. Subphotospheric differential rotation was derived using ring-diagram analysis of GONG++ full-disk dopplergrams of 1 min cadence. The coronal rotation was derived by using an automatic method to identify and track the small bright coronal structures in EIT full-disk images of 6 hours cadence. Results. We find that the SBCS rotate faster than the considered upper subphotospheric layer (3Mm) by about 0.5 deg/day at the equator. This result joins the results of several other magnetic features (sunspots, plages, faculae, etc.) with a higher rotation than the solar plasma. The rotation rate latitudinal gradients of the SBCS and the subphotospheric layers are very similar. The SBCS motion shows an acceleration of about 0.005 deg/day/month during the declining phase of solar cycle 23, whereas the angular velocity of subsurface layers does not display any evident variation with time, except for the well known torsional oscillation pattern. Finally, both subphotospheric and coronal rotations of the southern hemisphere are predominantly larger than those of the northern hemisphere. At latitudes where the north-south asymmetry of the angular velocity increases (decreases) with activity for the SBCS, it decreases (increases) for subphotospheric layers.Comment: 6pages, 8 figures, Accepted for publication in Astronomy and Astrophysic

    Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond Using Single-Crystal Silicon Hard Masks

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    A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low mode volume (Vm=1.062x({\lambda}/n)^3), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q=3x103.Comment: This article will be published in Applied Physics Letter

    Granular cell tumors of the urinary bladder

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    BACKGROUND: Granular cell tumors (GCTs) are extremely rare lesions of the urinary bladder with only nine cases being reported in world literature of which one was malignant. Generally believed to be of neural origin based on histochemical, immunohistochemical, and ultrastructural studies; they mostly follow a clinically benign course but are commonly mistaken for malignant tumors since they are solid looking, ulcerated tumors with ill-defined margins. MATERIALS AND METHODS: We herein report two cases of GCTs, one benign and one malignant, presenting with gross hematuria in a 14- and a 47-year-old female, respectively. RESULTS: Histopathology revealed characteristic GCTs with positive immunostaining for neural marker (S-100) and negative immunostaining for epithelial (cytokeratin, Cam 5.2, AE/A13), neuroendocrine (neuron specific enolase, chromogranin A, and synaptophysin) and sarcoma (desmin, vimentin) markers. The benign tumor was successfully managed conservatively with transurethral resection alone while for the malignant tumor, radical cystectomy, hysterectomy with bilateral salpingo-oophorectomy, anterior vaginectomy, plus lymph node dissection was done. Both cases show long-term disease free survival. CONCLUSION: We recommend careful pathologic assessment for establishing the appropriate diagnosis and either a conservative or aggressive surgical treatment for benign or localized malignant GCT of the urinary bladder, respectively

    Physics of Solar Prominences: II - Magnetic Structure and Dynamics

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    Observations and models of solar prominences are reviewed. We focus on non-eruptive prominences, and describe recent progress in four areas of prominence research: (1) magnetic structure deduced from observations and models, (2) the dynamics of prominence plasmas (formation and flows), (3) Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and large-scale patterns of the filament channels in which prominences are located. Finally, several outstanding issues in prominence research are discussed, along with observations and models required to resolve them.Comment: 75 pages, 31 pictures, review pape
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