1,708 research outputs found

    Friendly-Contention Ads Using Multiple Endorsers: Assessing Source Effects On Attribute Perceptions And Brand Attitudes

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    Our study is a preliminary investigation of multiple-source friendly-contention ads in which various endorsers argue about the brand's main benefit(s).  The results demonstrate that such an ad convinced viewers that originally seemingly inconsistent attributes and benefits could both be found in the advertised brand.  Further, the tested advertising format produced more favorable brand attitudes than did an equivalently informative single-source ad version.  The argumentative ad appears entirely appropriate in industries where a company wishes to target heavy product users

    Literature Review Report: Services to Support Carers of People with Mental Health Problems

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    24^{24}Mg(pp, α\alpha)21^{21}Na reaction study for spectroscopy of 21^{21}Na

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    The 24^{24}Mg(pp, α\alpha)21^{21}Na reaction was measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to better constrain spins and parities of energy levels in 21^{21}Na for the astrophysically important 17^{17}F(α,p\alpha, p)20^{20}Ne reaction rate calculation. 31 MeV proton beams from the 25-MV tandem accelerator and enriched 24^{24}Mg solid targets were used. Recoiling 4^{4}He particles from the 24^{24}Mg(pp, α\alpha)21^{21}Na reaction were detected by a highly segmented silicon detector array which measured the yields of 4^{4}He particles over a range of angles simultaneously. A new level at 6661 ±\pm 5 keV was observed in the present work. The extracted angular distributions for the first four levels of 21^{21}Na and Distorted Wave Born Approximation (DWBA) calculations were compared to verify and extract angular momentum transfer.Comment: 11 pages, 6 figures, proceedings of the 18th International Conference on Accelerators and Beam Utilization (ICABU2014

    New γ\gamma-ray Transitions Observed in 19^{19}Ne with Implications for the 15^{15}O(α\alpha,γ\gamma)19^{19}Ne Reaction Rate

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    The 15^{15}O(α\alpha,γ\gamma)19^{19}Ne reaction is responsible for breakout from the hot CNO cycle in Type I x-ray bursts. Understanding the properties of resonances between Ex=4E_x = 4 and 5 MeV in 19^{19}Ne is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of 9/2−^- and 7/2−^-, respectively. Gamma-ray transitions from these states were studied using triton-γ\gamma-γ\gamma coincidences from the 19^{19}F(3^{3}He,tγt\gamma)19^{19}Ne reaction measured with GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the JπJ^\pi values are actually 7/2−^- and 9/2−^-, respectively. These assignments are consistent with the values in the 19^{19}F mirror nucleus and in contrast to previously accepted assignments

    Key 19^{19}Ne states identified affecting γ\gamma-ray emission from 18^{18}F in novae

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    Detection of nuclear-decay γ\gamma rays provides a sensitive thermometer of nova nucleosynthesis. The most intense γ\gamma-ray flux is thought to be annihilation radiation from the β+\beta^+ decay of 18^{18}F, which is destroyed prior to decay by the 18^{18}F(pp,α\alpha)15^{15}O reaction. Estimates of 18^{18}F production had been uncertain, however, because key near-threshold levels in the compound nucleus, 19^{19}Ne, had yet to be identified. This Letter reports the first measurement of the 19^{19}F(3^{3}He,tγt\gamma)19^{19}Ne reaction, in which the placement of two long-sought 3/2+^+ levels is suggested via triton-γ\gamma-γ\gamma coincidences. The precise determination of their resonance energies reduces the upper limit of the rate by a factor of 1.5−171.5-17 at nova temperatures and reduces the average uncertainty on the nova detection probability by a factor of 2.1.Comment: 6 pages, 4 figure

    Recent direct reaction experimental studies with radioactive tin beams

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    Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z=50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, N=82, and neutron-deficient, N=50, regions. Here we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in 131Sn from across the N=82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn. In both cases, measurements of gamma rays in coincidence with charged particles proved to be invaluable.Comment: 11 pages, 5 figures, Zakopane Conference on Nuclear Physics "Extremes of the Nuclear Landscape", Zakopane, Poland, August 31 - September 7, 201

    Development of the (d,n) proton-transfer reaction in inverse kinematics for structure studies

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    Transfer reactions have provided exciting opportunities to study the structure of exotic nuclei and are often used to inform studies relating to nucleosynthesis and applications. In order to benefit from these reactions and their application to rare ion beams (RIBs) it is necessary to develop the tools and techniques to perform and analyze the data from reactions performed in inverse kinematics, that is with targets of light nuclei and heavier beams. We are continuing to expand the transfer reaction toolbox in preparation for the next generation of facilities, such as the Facility for Rare Ion Beams (FRIB), which is scheduled for completion in 2022. An important step in this process is to perform the (d,n) reaction in inverse kinematics, with analyses that include Q-value spectra and differential cross sections. In this way, proton-transfer reactions can be placed on the same level as the more commonly used neutron-transfer reactions, such as (d,p), (9Be,8Be), and (13C,12C). Here we present an overview of the techniques used in (d,p) and (d,n), and some recent data from (d,n) reactions in inverse kinematics using stable beams of 12C and 16O.Comment: 9 pages, 4 figures, presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Polan

    Obtaining high resolution excitation functions with an active thick-target approach and validating them with mirror nuclei

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    Measurement of fusion excitation functions for stable nuclei has largely been restricted to nuclei with significant natural abundance. Typically, to investigate neighboring nuclei with low natural abundance has required obtaining isotopically enriched material. This restriction often limits the ability to perform such measurements. We report the measurement of a high quality fusion excitation function for a 17^{17}O beam produced from unenriched material with 0.038\% natural abundance. The measurement is enabled by using an active thick-target approach and the accuracy of the result is validated using its mirror nucleus 17^{17}F and resonances. The result provides important information about the average fusion cross-section for the oxygen isotopic chain as a function of neutron excess.Comment: 4 pages, 4 figure
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