1,252 research outputs found

    INVESTIGATION OF INNER AND OUTER SUBSHELLS VIA TRANSFER REACTIONS

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    Transfer reactions, investigated a high incident energy (from 100 to 300 MeV), have considerably increased our knowledge of the nuclear response function to a particular simple mode of excitation of the nucleus. These reactions are particularly well suited to the study of high spin inner and outer subshells. The advantages of such approach are illustrated using few characteristic examples. a) Strong selectivity in angular momentum transfer, determination of the spin J of the inner hole state using polarized protonbeam in the case of one nucleon pick-up reaction. b) New experimental results via the (α, 6He) reaction at 218 MeV incident energy are obtained on the two-nucleon strength distributions in medium-heavy nuclei. c) First evidence of proton and neutron single-particle strengths at high excitation energy (5 to 15 MeV) in heavy nuclei are reported using the (α, t) (α, 3He) and (3He, d) stripping reactions. The experimental results will be compared to the predictions of nuclear models which take into account explicitly the coupling between single-particle and collective states in order to explain the observed fragmentation and spreading of the single-particle strength

    The diet of the Tasmanian Devil, Sarcophilus harrisii, as determined from analysis of scat and stomach contents

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    Knowledge of the diets of carnivores is an essential precursor to understanding their role as predators in ecosystems. To date, understanding of the diet of Tasmanian Devils, Sarcophilus harrisii, is limited and based upon largely qualitative descriptions. We examined the diets of Tasmanian Devils at six sites by identifying undigested hair, bone and feathers found in their scats. These sites range across different habitat types in coastal and inland Tasmania, and encompass devil populations that are known as both free of the Devil Facial Tumour Disease (DFTD) and populations that are infected by the disease. Tasmanian Devil scats at coastal sites (n=27) contained ten species of mammal, as well as birds, fish and insects. Scats collected from inland sites (n= 17) were comprised of six mammalian species, birds and invertebrates. The most common food items were birds, Common Brushtail and Ringtail possums (Trichosurus vulpecula and Pseudocheirus peregrinus respectively), Tasmanian Pademelons (Thylogale billardierii) and Bennett's Wallabies (Macropus ruftgriseus). O fall the scats, 61% contained only one food group, 32% contained two groups, 4% contained three food items and only one scat (2%) contained four food groups. We supplement this information with stomach contents from road-killed devils, and compare our results with those of previous studies, with a view to furthering our understanding ofthe ecology ofthe threatened Tasmanian Devil. Such information will be important for the management of wild and captive devil populations, particularly in light of DFTD

    Polymyxin-Resistant Acinetobacter spp. Isolates: What is Next?

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    Univ Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilWeb of Scienc

    Approches expérimentales des transitions delta S=1, delta T=1 dans les noyaux moyens et lourds

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    École thématiqu

    Structure nucléaire au moyen de faisceau d'ions radioactifs accélérés

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    École thématiqu

    Ground state correlations and structure of odd spherical nuclei

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    It is well known that the Pauli principle plays a substantial role at low energies because the phonon operators are not ideal boson operators. Calculating the exact commutators between the quasiparticle and phonon operators one can take into account the Pauli principle corrections. Besides the ground state correlations due to the quasiparticle interaction in the ground state influence the single particle fragmentation as well. In this paper, we generalize the basic QPM equations to account for both mentioned effects. As an illustration of our approach, calculations on the structure of the low-lying states in 131^{131}Ba have been performed.Comment: 12 pages, 1 figur

    Bond behaviour of rebar in concrete at elevated temperatures:a soft computing approach

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    This paper assesses the capability of using a new data-driven approach to predict the bond strength between steel rebar and concrete subjected to high temperatures. The analysis has been conducted using a novel evolutionary polynomial regression analysis (EPR-MOGA) that employs soft computing techniques, and new correlations have been proposed. The proposed correlations provide better predictions and enhanced accuracy than existing approaches, such as classical regression analysis. Based on this novel approach, the resulting correlations have achieved a lower mean absolute error (𝑀𝐴𝐸), and root mean square error (𝑅𝑀𝑆𝐸), a mean (𝜇) close to the optimum value (1.0) and a higher coefficient of determination (R2) compared to available correlations, which use classical regression analysis. Based on their enhanced performance, the proposed correlations can be used to obtain better optimised and more robust design calculations

    Blind Normalization of Speech From Different Channels

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    We show how to construct a channel-independent representation of speech that has propagated through a noisy reverberant channel. This is done by blindly rescaling the cepstral time series by a non-linear function, with the form of this scale function being determined by previously encountered cepstra from that channel. The rescaled form of the time series is an invariant property of it in the following sense: it is unaffected if the time series is transformed by any time-independent invertible distortion. Because a linear channel with stationary noise and impulse response transforms cepstra in this way, the new technique can be used to remove the channel dependence of a cepstral time series. In experiments, the method achieved greater channel-independence than cepstral mean normalization, and it was comparable to the combination of cepstral mean normalization and spectral subtraction, despite the fact that no measurements of channel noise or reverberations were required (unlike spectral subtraction).Comment: 25 pages, 7 figure
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