52,692 research outputs found

    Australian Fathers\u27 Study: What influences paternal engagement with antenatal care?

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    This mixed-methods study explores factors associated with and levels of engagement of fathers in antenatal care. One hundred expectant fathers were recruited from antenatal clinics and community settings in Western Australia. They completed validated questionnaires. Eighty-three percent of expectant fathers reported a lack of engagement with antenatal care. Factors significantly associated with lack of engagement in multivariate analysis were working more than 40 hours a week and lack of adequate consultation by antenatal care staff. In qualitative analysis, 6 themes emerged in association with a lack of engagement. They were role in decision making, time pressures, the observer effect, lack of knowledge, barriers to attendance, and feeling unprepared or anxious. Care providers should involve fathers in consultations to improve paternal engagement

    A 233 km Tunnel for Lepton and Hadron Colliders

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    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e+e−e^+e^-, ppˉp \bar{p}, and μ+μ−\mu^+ \mu^- collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e+e−e^+e^- colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e+e−e^+ e^- collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV ppˉp \bar{p} collider uses the high intensity Fermilab pˉ\bar{p} source, exploits high cross sections for ppˉp \bar{p} production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.Comment: LaTex, 6 pages, 1 figure, Advanced Accelerator Concepts Workshop, Austin, TX, 10-15 June 201

    In-plane ferromagnetism in charge-ordering Na0.55CoO2Na_{0.55}CoO_2

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    The magnetic and transport properties are systematically studied on the single crystal Na0.55CoO2Na_{0.55}CoO_2 with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic ordering is observed in susceptibility below 20 K with the magnetic field parallel to Co-O plane, while a negligible behavior is observed with the field perpendicular to the Co-O plane. It definitely gives a direct evidence for the existence of in-plane ferromagnetism below 20 K. The observed magnetoresistance (MR) of 30 % at the field of 6 T at low temperatures indicates an unexpectedly strong spin-charge coupling in triangle lattice systems.Comment: 4 pages, 5 figure

    Thermal Bremsstrahlung Radiation in a Two-Temperature Plasma

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    In the normal one-temperature plasma the motion of ions is usually neglected when calculating the Bremsstrahlung radiation of the plasma. Here we calculate the Bremsstrahlung radiation of a two-temperature plasma by taking into account of the motion of ions. Our results show that the total radiation power is always lower if the motion of ions is considered. We also apply the two-temperature Bremsstrahlung radiation mechanism for an analytical Advection-Dominated Accretion Flow (ADAF) model; we find the two-temperature correction to the total Bremsstrahlung radiation for ADAF is negligible.Comment: 5 pages, 4 figures, accepted for publication in CHJAA. Some discussions and references adde

    Angular-dependent Magnetoresistance Oscillations in Na0.48_{0.48}CoO2_{2} Single Crystal

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    We report measurements of the c-axis angular-dependent magnetoresistance (AMR) for a Na0.48_{0.48}CoO2_{2} single crystal, with a magnetic field of 10 T rotating within Co-O planes. Below the metal-insulator transition temperature induced by the charge ordering, the oscillation of the AMR is dominated by a two-fold rotational symmetry. The amplitudes of the oscillation corresponding to the four- and six-fold rotational symmetries are distinctive in low temperatures, but they merge into the background simultaneously at about 25 K. The six-fold oscillation originates naturally from the lattice symmetry. The observation of the four-fold rotational symmetry is consistent with the picture proposed by Choy, et al., that the Co lattice in the charge ordered state will split into two orthorhombic sublattice with one occupied by Co3+^{3+} ions and the other by Co4+^{4+} ions. We have also measured the c-axis AMR for Na0.35_{0.35}CoO2_{2} and Na0.85_{0.85}CoO2_{2} single crystals, and found no evidence for the existence of two- and four-fold symmetries.Comment: 4 pages, 6 figures. Submitted to PR

    Evidence of s-wave pairing symmetry in layered superconductor Li0.68_{0.68}NbO2_2 from the specific heat measurement

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    A high quality superconducting Li0.68_{0.68}NbO2_2 polycrystalline sample was synthesized by deintercalation of Li ions from Li0.93_{0.93}NbO2_2. The field dependent resistivity and specific heat were measured down to 0.5 K. The upper critical field Hc2(T)H_{c2} (T) is deduced from the resistivity data and Hc2(0)H_{c2}(0) is estimated to be ∼2.98\sim 2.98 T. A notable specific heat jump is observed at the superconducting transition temperature Tc∼5.0T_c \sim 5.0 K at zero field. Below TcT_c, the electronic specific heat shows a thermal activated behavior and agrees well with the theoretical result of the BCS s-wave superconductors. It indicates that the superconducting pairing in Li0.68_{0.68}NbO2_2 has s-wave symmetry.Comment: 4 pages, 5 figure

    Unparticle effects in rare (t -> c g g) decay

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    Rare (t -> c g g) decay can only appear at loop level in the Standard Model (SM), and naturally they are strongly suppressed. These flavor changing decays induced by the mediation of spin-0 and spin-2 unparticles, can appear at tree level in unparticle physics. In this work the virtual effects of unparticle physics in the flavor-changing (t -> c g g) decay is studied. Using the SM result for the branching ratio of the (t -> c g g) decay, the parameter space of d_U and Lambda_U, where the branching ratio of this decay exceeds the one predicted by the SM, is obtained. Measurement of the branching ratio larger than 10^(-9) can give valuable information for establishing unparticle physics.Comment: 15 pages, 7 figures, LaTeX formatte

    BDGS: A Scalable Big Data Generator Suite in Big Data Benchmarking

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    Data generation is a key issue in big data benchmarking that aims to generate application-specific data sets to meet the 4V requirements of big data. Specifically, big data generators need to generate scalable data (Volume) of different types (Variety) under controllable generation rates (Velocity) while keeping the important characteristics of raw data (Veracity). This gives rise to various new challenges about how we design generators efficiently and successfully. To date, most existing techniques can only generate limited types of data and support specific big data systems such as Hadoop. Hence we develop a tool, called Big Data Generator Suite (BDGS), to efficiently generate scalable big data while employing data models derived from real data to preserve data veracity. The effectiveness of BDGS is demonstrated by developing six data generators covering three representative data types (structured, semi-structured and unstructured) and three data sources (text, graph, and table data)

    Interpolation function of the genocchi type polynomials

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    The main purpose of this paper is to construct not only generating functions of the new approach Genocchi type numbers and polynomials but also interpolation function of these numbers and polynomials which are related to a, b, c arbitrary positive real parameters. We prove multiplication theorem of these polynomials. Furthermore, we give some identities and applications associated with these numbers, polynomials and their interpolation functions.Comment: 14 page
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