On the Corrosion Resistance of Porous Electroplated Zinc Coatings in Different Corrosive Media

The corrosion resistance of an electroplated (EP) Zn coating whose surface was chemically etched to produce surface defects (pores) is investigated in this work. Impedance and DC polarisation measururements were employed to study the behaviour of such coating in various corrosive media (NaCl, NaOH and rain water). Four different faradaic relaxation processes were clearly revealed in different NaCl concentrations (from 0.1M to 1M). In the most concentrated solutions at least three relaxation processes at low frequencies (LF) appeared and were related to zinc deposition and dissolution. At lower concentrations and depending on the pH, only one process was observed. The charge transfer resistance (Rct) and the corrosion current (Icorr) were practically stable in the pH range 5 to 10. In deaerated NaCl 0.1M, the EIS diagrams showed two time-constants at very close frequencies. From the EIS diagrams the porous nature of the coating was highlighted and showed that the dissolution mechanisms occurred at the base of the pores

dispersal and reception in northern italy comparing systems along the brenner route

In the last decades, policy restrictions and practices at national and local levels have curtailed the rights of seekers and holders of international protection, thus impacting on their lives and on the territories they transit through. This is particularly evident in border contexts. Various border areas have gradually transformed into internal hotspots, with increasing border enforcement. This includes Brenner, situated at the border between Italy and Austria. In the wider Brenner route area, particularly in the nearby Italian cities of Verona, Trento and Bolzano, "spaces of transit" have emerged and both public and humanitarian actors have been "forced" to deal with it. This chapter draws upon the work of the multilevel governance of migration (Caponio and Borkert 2010), and on the proliferation of borders (Mezzadra and Neilson 2016), to present a comparative analysis of the reception scenario in these three cities. By building on qualitative data analysis (legal analysis of policy documents, content analysis of interviews and newspaper articles), it discusses to what extent and how the respective local systems of reception have managed to cater for migrants that transit through them. Similarities and differences are pointed out, as well as the relevance of factors such as geographical proximity in influencing the respective approaches

ZEEMAN EFFECTS OF THE PURELY CUBIC FIELD EMISSION LINE OF MgO:Cr3+MgO:C^{3+}_{r} CRYSTALS

$^{*}$Present address: Physics Department. The joins Hopkins University, Baltimore, Maryland.Author Institution: Bell Telephone Laboratories, Incorporated“The transverse Zeeman effect, has been studied of the most conspicuous red emission line ($14,319 cm^{-1}$) of a $MgO:C^{3+}_{r}$ single crystal. This line may be considered to be due to the chromium impurities with purely cubic environments. The six Zeeman patterns have been examined experimentally, with a magnetic field parallel to the. [001], [110], and [111] directions, and with polarizations $\sigma$ and $\pi$; for each direction of the magnetic field. Comparing these patterns with the theoretical ones, it has been found that the line is a magnetic dipole radiation due to the $t^{3}_{2} \ {^{2}E} \to t^{3}_{2} \ {^{4}A_{2}}$ transition. It has also been found that, at least seemingly, the degeneracy of the initial $^{2} E$ state is not removed, in other words, the effect of the Jahn-Teller distortion does not appear in this spectrum. The longitudinal Zeeman effect will be discussed in terms of circular polarization.