24,330 research outputs found

    Real-time diagnostics of gas/water assisted injection moulding using integrated ultrasonic sensors

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    YesAn ultrasound sensor system has been applied to the mould of both the water and gas assisted injection moulding processes. The mould has a cavity wall mounted pressure sensor and instrumentation to monitor the injection moulding machine. Two ultrasound sensors are used to monitor the arrival of the fluid (gas or water) bubble tip through the detection of reflected ultrasound energy from the fluid polymer boundary and the fluid bubble tip velocity through the polymer melt is estimated. The polymer contact with the cavity wall is observed through the reflected ultrasound energy from that boundary. A theoretically based estimation of the residual wall thickness is made using the ultrasound reflection from the fluid (gas or water) polymer boundary whilst the samples are still inside the mould and a good correlation with a physical measurement is observed

    Interactions of a String Inspired Graviton Field

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    We continue to explore the possibility that the graviton in two dimensions is related to a quadratic differential that appears in the anomalous contribution of the gravitational effective action for chiral fermions. A higher dimensional analogue of this field might exist as well. We improve the defining action for this diffeomorphism tensor field and establish a principle for how it interacts with other fields and with point particles in any dimension. All interactions are related to the action of the diffeomorphism group. We discuss possible interpretations of this field.Comment: 12 pages, more readable, references adde

    Pseudoscalar mixing in J/psi and psi(2S) decay

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    Based on the branching fractions of J/psi(psi(2S))-> VP from different collaborations, the pseudoscalar mixing is extensively discussed with a well established phenomenological model. The mixing angle is determined to be -14 degree by fitting to the new world average if only quark content is considered. After taking into account the gluonic content in eta and eta prime simultaneously, the investigation shows that eta favors only consisting of light quarks, while the gluonic content of eta prime is Z_{eta prime}^2=0.30\pm0.24.Comment: 8 page

    Scaling law for the electromagnetic form factors of the proton

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    The violation of the scaling law for the electric and magnetic form factors of the proton are examined within the cloudy bag model. The suppression of the ratio of the electric and magnetic form factors is natural in the bag model. The pion cloud plays a moderate role in understanding the recent data from TJNAF.Comment: 8 pages, REVTeX, 2 figures include

    Kondo screening in d-wave superconductors in a Zeeman field and implications for STM spectra of Zn-doped cuprates

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    We consider the screening of an impurity moment in a d-wave superconductor under the influence of a Zeeman magnetic field. Using the Numerical Renormalization Group technique, we investigate the resulting pseudogap Kondo problem, in particular the field-induced crossover behavior in the vicinity of the zero-field boundary quantum phase transition. The impurity spectral function and the resulting changes in the local host density of states are calculated, giving specific predictions for high-field STM measurements on impurity-doped cuprates.Comment: 5 pages, 4 figs, (v2) remark on c-axis field added, discussion extended, (v3) final version as publishe

    Simulations of electromagnetic effects in high frequency capacitively coupled discharges using the Darwin approximation

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    The Darwin approximation is investigated for its possible use in simulation of electromagnetic effects in large size, high frequency capacitively coupled discharges. The approximation is utilized within the framework of two different fluid models which are applied to typical cases showing pronounced standing wave and skin effects. With the first model it is demonstrated that Darwin approximation is valid for treatment of such effects in the range of parameters under consideration. The second approach, a reduced nonlinear Darwin approximation-based model, shows that the electromagnetic phenomena persist in a more realistic setting. The Darwin approximation offers a simple and efficient way of carrying out electromagnetic simulations as it removes the Courant condition plaguing explicit electromagnetic algorithms and can be implemented as a straightforward modification of electrostatic algorithms. The algorithm described here avoids iterative schemes needed for the divergence cleaning and represents a fast and efficient solver, which can be used in fluid and kinetic models for self-consistent description of technical plasmas exhibiting certain electromagnetic activity

    Decays of Zb(+) and Zb'(+) as hadronic molecules

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    The two newly observed hidden-bottom mesons Zb(10610) and Zb'(10650) with quantum numbers J(P) = 1(+) are considered as hadronic molecules composed of BB(*) and B(*)B(*), respectively. We give predictions for the widths of the strong two-body decays Zb(+) to Upsilon(nS) + pi(+) and Zb'(+) to Upsilon(nS) + pi(+) in a phenomenological Lagrangian approach.Comment: 9 page

    Outpatient prescription practices in patients with atrial fibrillation (from the NCDR PINNACLE registry)

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    This study sought to evaluate inappropriate prescribing practices in an atrial fibrillation (AF) population, as outlined by the 2016 ACC/AHA Clinical Performance and Quality Measures for Adults with Atrial Fibrillation or Atrial Flutter document. The 2016 AF quality measures document specified medications to avoid in certain AF populations, including aspirin and anticoagulant combination therapy in patients without cardiovascular disease, and non-dihydropyridine calcium channel blockers in patients with reduced ejection fraction. Using data from the NCDR PINNACLE registry, a national outpatient cardiology practice registry, we assessed rates of inappropriate prescription of two types of medications among AF outpatients from 5/1/2008-5/1/2016. Overall rates of inappropriate prescription and variation by practice were calculated. Patient and practice factors associated with inappropriate prescription were assessed in adjusted analyses. A total of 107,759 of 658,250 (16.4%) patients without cardiovascular disease were inappropriately prescribed an antiplatelet and anticoagulant together, and 5,731 of 150,079 (3.8%) patients with reduced ejection fraction were inappropriately prescribed a non-dihydropyridine calcium channel blocker. Overall, 14.8% of AF patients were prescribed medications that were not recommended. Both patient and practice factors were associated with inappropriate prescribing, and the adjusted practice-level median odds ratio for inappropriate prescription was 1.70 (95% CI: 1.61-1.82), indicating a 70% likelihood that 2 random practices would treat identical AF patients differently. In a large registry of AF patients treated in cardiology practices, overall rates of inappropriate prescription practices, as defined by the 2016 AF quality measures, were relatively low, but significant practice variation was present

    On the conservation of the slow conformational dynamics within the amino acid kinase family: NAGK the paradigm

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    N-Acetyl-L-Glutamate Kinase (NAGK) is the structural paradigm for examining the catalytic mechanisms and dynamics of amino acid kinase family members. Given that the slow conformational dynamics of the NAGK (at the microseconds time scale or slower) may be rate-limiting, it is of importance to assess the mechanisms of the most cooperative modes of motion intrinsically accessible to this enzyme. Here, we present the results from normal mode analysis using an elastic network model representation, which shows that the conformational mechanisms for substrate binding by NAGK strongly correlate with the intrinsic dynamics of the enzyme in the unbound form. We further analyzed the potential mechanisms of allosteric signalling within NAGK using a Markov model for network communication. Comparative analysis of the dynamics of family members strongly suggests that the low-frequency modes of motion and the associated intramolecular couplings that establish signal transduction are highly conserved among family members, in support of the paradigm sequence→structure→dynamics→function © 2010 Marcos et al
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