4,537 research outputs found

    Ionization from Fe atoms incident on various gas targets

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    Ionization from iron atoms incident on target gases of helium, neon, nitrogen, carbon dioxide, and ai

    High voltage breakdown initiated by particle impact

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    High voltage breakdown initiated by particle impact across electrode ga

    Ultrasound Guided Placement of Single-Lumen Peripheral Intravenous Catheters in the Internal Jugular Vein

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    Introduction: The peripheral internal jugular (IJ), also called the “easy IJ,” is an alternative to peripheral venous access reserved for patients with difficult intravenous (IV) access. The procedure involves placing a single-lumen catheter in the IJ vein under ultrasound (US) guidance. As this technique is relatively new, the details regarding the ease of the procedure, how exactly it should be performed, and the safety of the procedure are uncertain. Our primary objective was to determine the success rate for peripheral IJ placement. Secondarily, we evaluated the time needed to complete the procedure and assessed for complications. Methods: This was a prospective, single-center study of US-guided peripheral IJ placement using a 2.5-inch, 18-gauge catheter on a convenience sample of patients with at least two unsuccessful attempts at peripheral IV placement by nursing staff. Peripheral IJ lines were placed by emergency medicine (EM) attending physicians and EM residents who had completed at least five IJ central lines. All physicians who placed lines for the study watched a 15-minute lecture about peripheral IJ technique. A research assistant monitored each line to assess for complications until the patient was discharged. Results: We successfully placed a peripheral IJ in 34 of 35 enrolled patients (97.1%). The median number of attempts required for successful cannulation was one (interquartile range (IQR): 1 to 2). The median time to successful line placement was 3 minutes and 6 seconds (IQR: 59 seconds to 4 minutes and 14 seconds). Two lines failed after placement, and one of the 34 successfully placed peripheral IJ lines (2.9%) had a complication – a local hematoma. There were, however, no arterial punctures or pneumothoraces. Although only eight of 34 lines were placed using sterile attire, there were no line infections. Conclusion: Our research adds to the growing body of evidence supporting US-guided peripheral internal jugular access as a safe and convenient procedure alternative for patients who have difficult IV access

    Slip or not slip? A methodical examination of the interface formation model using two-dimensional droplet spreading on a horizontal planar substrate as a prototype system

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    We consider the spreading of a thin two-dimensional droplet on a planar substrate as a prototype system to compare the contemporary model for contact line motion based on interface formation of Shikhmurzaev [Int. J. Multiphas. Flow 19, 589 (1993)], to the more commonly used continuum fluid dynamical equations augmented with the Navier-slip condition. Considering quasistatic droplet evolution and using the method of matched asymptotics, we find that the evolution of the droplet radius using the interface formation model reduces to an equivalent expression for a slip model, where the prescribed microscopic dynamic contact angle has a velocity dependent correction to its static value. This result is found for both the original interface formation model formulation and for a more recent version, where mass transfer from bulk to surface layers is accounted for through the boundary conditions. Various features of the model, such as the pressure behaviour and rolling motion at the contact line, and their relevance, are also considered in the prototype system we adopt.Comment: 45 pages, 18 figure

    From Service to Experience: Understanding and Defining the Hospitality Business

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    Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the host–guest relationship, generosity, theatre and performance, ‘lots of little surprises’, and the security of strangers – a focus that provides guests with experiences that are personal, memorable and add value to their lives

    Comparison of Power Dependence of Microwave Surface Resistance of Unpatterned and Patterned YBCO Thin Film

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    The effect of the patterning process on the nonlinearity of the microwave surface resistance RSR_S of YBCO thin films is investigated. With the use of a sapphire dielectric resonator and a stripline resonator, the microwave RSR_S of YBCO thin films was measured before and after the patterning process, as a function of temperature and the rf peak magnetic field in the film. The microwave loss was also modeled, assuming a Jrf2J_{rf}^2 dependence of ZS(Jrf)Z_S(J_{rf}) on current density JrfJ_{rf}. Experimental and modeled results show that the patterning has no observable effect on the microwave residual RSR_S or on the power dependence of RSR_S.Comment: Submitted to IEEE Trans. MT

    Ionic liquid crystals based on 3-perfluoalkyl-1,2,4-triazol-4-ium salts

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    Liquid-crystalline ionic liquids (LC-ILs) are a class of organic materials that of great current interest: they are defined as organic salts that possess the properties of two interesting kinds of material \u2013 ionic liquids (ILs) and liquid crystals (LCs). LC-ILs combine many interesting features of ILs (e.g. low volatility and the ability to dissolve solutes with a range of polarities) as well as many attractive properties of LCs (e.g. their intrinsic order and anisotropy). This provides unique opportunities that can be exploited in many different fields, for example their use as solvents for extraction processes as well as electrolytes for batteries, fuel cells, and dye-sensitised solar cells1\u20134. These LC-ILs can also be used to immobilise transition-metal catalysts in the liquid phase of biphasic catalytic reactions1 or as reaction media in order to exert control, over the rate, regio- and/or stereochemical outcome of chemical reactions5,6. We are interested in LC-ILs that are obtained from molecules with small, planar structures based on alkyl and perfluoalkyl-1,2,4-triazol-4-ium salts7\u20139 (Scheme 1). This contribution will report the synthesis, structure and liquid-crystal properties of materials of this type and will discuss preliminary investigations into their physical properties and applications

    Quantum key distribution and 1 Gbit/s data encryption over a single fibre

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    We perform quantum key distribution (QKD) in the presence of 4 classical channels in a C-band dense wavelength division multiplexing (DWDM) configuration using a commercial QKD system. The classical channels are used for key distillation and 1 Gbps encrypted communication, rendering the entire system independent from any other communication channel than a single dedicated fibre. We successfully distil secret keys over fibre spans of up to 50 km. The separation between quantum channel and nearest classical channel is only 200 GHz, while the classical channels are all separated by 100 GHz. In addition to that we discuss possible improvements and alternative configurations, for instance whether it is advantageous to choose the quantum channel at 1310 nm or to opt for a pure C-band configuration.Comment: 9 pages, 7 figure
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