412 research outputs found

    Kabul Times (April 11, 1964, vol. 3, no. 37)

    Get PDF
    High-resolution photon scattering experiments have been performed on the nucleus 45Sc at the Darmstadt superconducting electron accelerator S-DALINAC using bremsstrahlung beams with end point energies of 5.0 and 7.0MeV. Energies, absolute cross-sections and decay widths of 50 states, most of them previously unknown, have been determined. The results are compared to (γ,γ \gamma{^\prime}) experiments on the neighbouring closed proton shell isotope 44Ca

    Immobilization of catalase via adsorption into natural and modified active carbon obtained from walnut in various methods

    Get PDF
    In the present work, the immobilization of catalase into natural active carbon and active carbon modified by hydrochloric acid was carried out. In the experimental section, the effects of pH, ionic strength andreaction temperature were chosen as parameters, with experiments performed in batch system. For the optimization of immobilization procedure, values of kinetic parameters were evaluated. It was observedthat storage and operational stabilities of the enzyme increased with immobilization. The results obtained from experiments showed that active carbon is a valuable support for the adsorption of enzymes

    Protective effects of aspirin and vitamin C against corn syrup consumption-induced cardiac damage through sirtuin-1 and HIF-1α pathway

    Get PDF
    Objective: The aim of this study was to investigate the protective effects of aspirin (AS) and vitamin C (VC) against cardiac damage induced by chronic corn syrup (CS) consumption via a mechanism involving sirtuin-1 (ST-1), hypoxia-inducible factor-1α (HIF-1α), and the caspase-3 pathway in rats. Methods: Forty male Sprague-Dawley rats (14-16 weeks) that weighed 250-300 g were randomly distributed into 5 groups, each containing 8 rats: control group, CS+AS group, CS+VC group, CS+AS+VC group, and CS group. AS (10 mg/kg/day) and VC (200 mg/kg/day) were orally given to the rats. F30 (30% fructose syrup solution) was given to the rats in drinking water for 6 weeks. The rats were sacrificed by exsanguination 24 h after the last administration. Blood samples and tissue were collected for biochemical, histopathological, and immunohistochemical examinations. Non-parametric Kruskal-Wallis test and Mann-Whitney U test used for the parameters without normal distribution and ANOVA and post-hoc LSD tests were used for parameters with a normal distribution to compare groups. Results: Uric acid, creatine kinase (CKMB), and lactate dehydrogenase (LDH) levels were increased in the CS group compared with the control group (1.45±0.39 and p=0.011; 3225.64±598.25 and p=0.004; 3906.83±1064.22 and p=0.002, respectively) and decreased in all the treatment groups. In addition, increased levels of MDA and decreased activity of CAT in the CS group (0.172±0.03 and p=0.000; 0.070±0.005 and p=0.007, respectively) were reversed with AS and VC therapy. A decrease in ST-1 activity and increases in caspase-3 and HIF-1 activities corrected by VC and AS therapy were observed. Conclusion: AS and VC, which display antioxidant and antiapoptotic activities, ameliorated cardiac damage induced by chronic fructose consumption by increasing the levels of ST-1 and decreasing the levels of HIF-1α and caspase-3. © 2016 by Turkish Society of Cardiology

    Investigation of octupole vibrational states in 150Nd via inelastic proton scattering (p,p'g)

    Full text link
    Octupole vibrational states were studied in the nucleus 150Nd^{150}\mathrm{Nd} via inelastic proton scattering with \unit[10.9]{MeV} protons which are an excellent probe to excite natural parity states. For the first time in 150Nd^{150}\mathrm{Nd}, both the scattered protons and the γ\gamma rays were detected in coincidence giving the possibility to measure branching ratios in detail. Using the coincidence technique, the B(E1)B(E1) ratios of the decaying transitions for 10 octupole vibrational states and other negative-parity states to the yrast band were determined and compared to the Alaga rule. The positive and negative-parity states revealed by this experiment are compared with Interacting Boson Approximation (IBA) calculations performed in the (spdf) boson space. The calculations are found to be in good agreement with the experimental data, both for positive and negative-parity states

    Parity assignments in 172,174Yb using polarized photons and the K quantum number in rare earth nuclei

    Full text link
    The 100 % polarized photon beam at the High Intensity gamma-ray Source (HIgS) at Duke University has been used to determine the parity of six dipole excitations between 2.9 and 3.6 MeV in the deformed nuclei 172,174 Yb in photon scattering (g,g') experiments. The measured parities are compared with previous assignments based on the K quantum number that had been assigned in Nuclear Resonance Fluorescence (NRF) experiments by using the Alaga rules. A systematic survey of the relation between gamma-decay branching ratios and parity quantum numbers is given for the rare earth nuclei.Comment: 5 pages, 6 figures, to be published in Phys. Rev.

    3D Face Reconstruction from Light Field Images: A Model-free Approach

    Full text link
    Reconstructing 3D facial geometry from a single RGB image has recently instigated wide research interest. However, it is still an ill-posed problem and most methods rely on prior models hence undermining the accuracy of the recovered 3D faces. In this paper, we exploit the Epipolar Plane Images (EPI) obtained from light field cameras and learn CNN models that recover horizontal and vertical 3D facial curves from the respective horizontal and vertical EPIs. Our 3D face reconstruction network (FaceLFnet) comprises a densely connected architecture to learn accurate 3D facial curves from low resolution EPIs. To train the proposed FaceLFnets from scratch, we synthesize photo-realistic light field images from 3D facial scans. The curve by curve 3D face estimation approach allows the networks to learn from only 14K images of 80 identities, which still comprises over 11 Million EPIs/curves. The estimated facial curves are merged into a single pointcloud to which a surface is fitted to get the final 3D face. Our method is model-free, requires only a few training samples to learn FaceLFnet and can reconstruct 3D faces with high accuracy from single light field images under varying poses, expressions and lighting conditions. Comparison on the BU-3DFE and BU-4DFE datasets show that our method reduces reconstruction errors by over 20% compared to recent state of the art

    A New Method of Probing the Phonon Mechanism in Superconductors including MgB2_{2}

    Get PDF
    Weak localization has a strong influence on both the normal and superconducting properties of metals. In particular, since weak localization leads to the decoupling of electrons and phonons, the temperature dependence of resistance (i.e., λtr\lambda_{tr}) is decreasing with increasing disorder, as manifested by Mooij's empirical rule. In addition, Testardi's universal correlation of TcT_{c} (i.e., λ\lambda) and the resistance ratio (i.e., λtr\lambda_{tr}) follows. This understanding provides a new means to probe the phonon mechanism in superconductors including MgB2_{2}. The merits of this method are its applicability to any superconductors and its reliability because the McMillan's electron-phonon coupling constant λ\lambda and λtr\lambda_{tr} change in a broad range, from finite values to zero, due to weak localization. Karkin et al's preliminary data of irradiated MgB2_{2} show the Testardi correlation, indicating that the dominant pairing mechanism in MgB2_{2} is the phonon-mediated interaction.Comment: 9 pages, latex, 3 figure

    Isospin Character of the Pygmy Dipole Resonance in 124Sn

    Full text link
    The pygmy dipole resonance has been studied in the proton-magic nucleus 124Sn with the (a,a'g) coincidence method at E=136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in (a,a'g) as well as in (g,g') reactions and a group of states at higher energies which is only excited in (g,g') reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance

    Investigation of photoneutron reactions close to and above the neutron emission threshold in the rare earth region

    Full text link
    We have investigated the photoneutron cross section of the isotopes 148,150^{148,150}Nd, 154^{154}Sm, and 154,160^{154,160}Gd close to the neutron emission threshold in photoactivation experiments at the Darmstadt superconducting electron linear accelerator S-DALINAC. Naturally composed targets were activated with a high-intensity bremsstrahlung beam at various energies and the reaction yields have been determined by measuring the activity of the produced radioactive isotopes with HPGe detectors. The results are compared to two different statistical model calculations.Comment: Accepted for publication in Physical Review

    Approaching the Gamow Window with Stored Ions : Direct Measurement of Xe 124 (p,γ) in the ESR Storage Ring

    Get PDF
    © 2019 American Physical Society. All rights reserved.We report the first measurement of low-energy proton-capture cross sections of Xe124 in a heavy-ion storage ring. Xe12454+ ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The Cs125 reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and γ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.Peer reviewedFinal Published versio
    corecore