Study of the inhibiting efficiency of the corrosion inhibitor (prop-2-yn-1-ol, methyloxirane) of mild steel in the chemical pickling (18.5% HCl)

The study of the inhibitory efficacy of prop-2-yn-1-ol, methyloxirane for corrosion control of mild steel in concentrated hydrochloric acid (18.5%) at temperature 80 °C (chemical pickling conditions of steel) was investigated using electrochemical and gravimetric methods for different concentrations. Using weight loss, and potentiodynamic polarization techniques and the morphological structure, the results shows that inhibitor had an excellent protection. The substance has demonstrated remarkable inhibition efficiency, and its inhibitory characteristics are stronger as concentrations increase (Inhibitory efficacy of up to 91 % for 1.2g/L). Based on the polarisation curves, the addition of the inhibitor in the HCl solution induces the decrease of the anodic current corresponding to the attack of the metal. The morphological structure was examined by scanning electron microscopy, which clearly shows this inhibitor's good protection, which delays the acid attack of bare steel with a uniform and bright pickling appearance

Spatial Graphs with Local Knots

It is shown that for any locally knotted edge of a 3-connected graph in $S^3$, there is a ball that contains all of the local knots of that edge and is unique up to an isotopy setwise fixing the graph. This result is applied to the study of topological symmetry groups of graphs embedded in $S^3$.Comment: 20 pages, 3 figures; in v. 2 the proof of Theorem 1 has been clarified, and other minor revisions have been mad

Q-Value and Half-Lives for the Double-Beta-Decay Nuclide 110Pd

The 110Pd double-beta decay Q-value was measured with the Penning-trap mass spectrometer ISOLTRAP to be Q = 2017.85(64) keV. This value shifted by 14 keV compared to the literature value and is 17 times more precise, resulting in new phase-space factors for the two-neutrino and neutrinoless decay modes. In addition a new set of the relevant matrix elements has been calculated. The expected half-life of the two-neutrino mode was reevaluated as 1.5(6) E20 yr. With its high natural abundance, the new results reveal 110Pd to be an excellent candidate for double-beta decay studies

On the validity of the Wigner-Seitz approximation in neutron star crust

The inner crust of neutron stars formed of nuclear clusters immersed in a neutron sea has been widely studied in the framework of the Wigner-Seitz approximation since the seminal work of Negele and Vautherin. In this article, the validity of this approximation is discussed in the framework of the band theory of solids. For a typical cell of $^{200}$Zr, present in the external layers of the inner crust, it is shown that the ground state properties of the neutron gas are rather well reproduced by the Wigner-Seitz approximation, while its dynamical properties depend on the energy scale of the process of interest or on the temperature. It is concluded that the Wigner-Seitz approximation is well suited for describing the inner crust of young neutron stars and the collapsing core of massive stars during supernovae explosions. However the band theory is required for low temperature fluid dynamics.Comment: 7 pages, with figures - PTH, version