6,053 research outputs found

    Studies on Positron-Hydrogen Ionization Cross Sections

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    Glass forming ability and soft-magnetic properties of Fe-based glassy alloys developed using high phosphorous pig Iron

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    Glass forming ability (GFA) and soft-magnetic behaviour of melt-spun Fe69C5.5P11.5Mn0.4Si2.3Cr1.8Mo1B8.5 (alloy 2) and Fe68C9P12Mn1Si3Nb2B5, (alloy 3) alloys prepared using high phosphorous pig iron (h-PI, Fe80C14P2.2Mn0.4Si3.4) has been studied. The glass formation, thermo-physical and soft-magnetic properties of the alloys were analyzed for different quenching rates by varying wheel speed as 23, 26, 33, 39 and 43 m/s. The simultaneous incorporation of alloying elements (Cr, Mo, Nb) and metalloids (C, B, P, Si) transforms h-PI to complete glassy alloy, even at low quenching rates. The melt quenching rate influences the thermal parameters and Curie temperature of glassy ribbons in an opposite way. Amongst all, FeCPMnSiCrMoB glassy alloy show superior combination of higher glass transition temperature of 788 K, super cooled region of 34 K, glass Curie temperature of 552 K, coercivity less than 13 A/m and maximum saturation magnetization of 1.1 T. In addition, the annealing treatment at 758 K improves magnetic softness (1.7 A/m) of the alloy by relaxation of quenched-in stresses. The comparison of developed glassy alloy with similar Fe-glassy alloys and SENNTIX type alloys show best combination of thermo-physical and magnetic properties. The glassy alloy prepared using blast furnace high phosphorous pig iron can be used for uniformly gapped soft-magnetic cores

    Supplementation of a western diet with golden kiwifruits (Actinidia chinensis var.'Hort 16A':) effects on biomarkers of oxidation damage and antioxidant protection

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    <p>Abstract</p> <p>Background</p> <p>The health positive effects of diets high in fruits and vegetables are generally not replicated in supplementation trials with isolated antioxidants and vitamins, and as a consequence the emphasis of chronic disease prevention has shifted to whole foods and whole food products.</p> <p>Methods</p> <p>We carried out a human intervention trial with the golden kiwifruit, Actinidia chinensis, measuring markers of antioxidant status, DNA stability, plasma lipids, and platelet aggregation. Our hypothesis was that supplementation of a normal diet with kiwifruits would have an effect on biomarkers of oxidative status. Healthy volunteers supplemented a normal diet with either one or two golden kiwifruits per day in a cross-over study lasting 2 × 4 weeks. Plasma levels of vitamin C, and carotenoids, and the ferric reducing activity of plasma (FRAP) were measured. Malondialdehyde was assessed as a biomarker of lipid oxidation. Effects on DNA damage in circulating lymphocytes were estimated using the comet assay with enzyme modification to measure specific lesions; another modification allowed estimation of DNA repair.</p> <p>Results</p> <p>Plasma vitamin C increased after supplementation as did resistance towards H<sub>2</sub>O<sub>2</sub>-induced DNA damage. Purine oxidation in lymphocyte DNA decreased significantly after one kiwifruit per day, pyrimidine oxidation decreased after two fruits per day. Neither DNA base excision nor nucleotide excision repair was influenced by kiwifruit consumption. Malondialdehyde was not affected, but plasma triglycerides decreased. Whole blood platelet aggregation was decreased by kiwifruit supplementation.</p> <p>Conclusion</p> <p>Golden kiwifruit consumption strengthens resistance towards endogenous oxidative damage.</p

    Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

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    Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel pˉpe+e\bar p p \to e^+ e^- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.\textit{i.e.} pˉpπ+π\bar p p \to \pi^+ \pi^-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

    Interferometry of Direct Photons in Central 280Pb+208Pb Collisions at 158A GeV

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    Two-particle correlations of direct photons were measured in central 208Pb+208Pb collisions at 158 AGeV. The invariant interferometric radii were extracted for 100<K_T<300 MeV/c and compared to radii extracted from charged pion correlations. The yield of soft direct photons, K_T<300 MeV/c, was extracted from the correlation strength and compared to theoretical calculations.Comment: 5 pages, 4 figure

    Systematics of Inclusive Photon Production in 158 AGeV Pb Induced Reactions on Ni, Nb, and Pb Targets

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    The multiplicity of inclusive photons has been measured on an event-by-event basis for 158 AGeV Pb induced reactions on Ni, Nb, and Pb targets. The systematics of the pseudorapidity densities at midrapidity (rho_max) and the width of the pseudorapidity distributions have been studied for varying centralities for these collisions. A power law fit to the photon yield as a function of the number of participating nucleons gives a value of 1.13+-0.03 for the exponent. The mean transverse momentum, , of photons determined from the ratio of the measured electromagnetic transverse energy and photon multiplicity, remains almost constant with increasing rho_max. Results are compared with model predictions.Comment: 16 pages including 4 figure
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