In-situ study of corrosion of commercial SD memory card by local electrochemical techniques

MSE-

In-situ study of corrosion phenomena on electronic devices by local electrochemical techniques

MSE-

Localised aqueous corrosion of electroless nickel immersion gold-coated copper

Electroless nickel (Ni) immersion gold (Au), commonly referred to by the acronym ENIG, is the most common protective coating applied on the exposed copper (Cu) traces of printed circuit boards (PCBs). In this work, we elucidate the local corrosion mechanism of the ENIG-Cu system by applying microscopic, surface analysis and electrochemical techniques with high spatial resolution to provide a comprehensive understanding of the complex local corrosion mechanism of the ENIG-Cu system. The corrosion initiation is highly localised and associated with pores or micro-defects in the Au layer. The corrosion initiates by the dissolution of the underlying Ni layer, being less noble than Au. The dissolution propagates in lateral and perpendicular directions relative to the surface in an elliptical fashion. With time, the direction of corrosion propagation changes to a predominantly lateral attack of the Ni layer. The corrosion process is governed by the cathode/anode ratio of the Au/Ni galvanic couple.Team Yaiza Gonzalez GarciaTeam Arjan Mo

Iranian Mathematical Society Title: . On the category of geometric spaces and the category of (geometric) hypergroups ON THE CATEGORY OF GEOMETRIC SPACES AND THE CATEGORY OF (GEOMETRIC) HYPERGROUPS

Abstract. In this paper first we define the morphism between geometric spaces in two different types. We construct two categories of U − GESP and L − GESP from geometric spaces then investigate some properties of the two categories, for instance U − GESP is topological. The relation between hypergroups and geometric spaces is studied. By constructing the category SNS − Hv of Hvgroups we answer the question that which construction of hyperstructures on the category of sets has free object in the sense of universal property. At the end we define the category of geometric hypergroups and we study its relation with the category of hypergroup

Insulation Reliability of Superconductive Cables

High current capability, good integration in urban area and zero external magnetic field are advantages of HTS cables that make them interesting for implementation in the Netherlands. So far experience with HTS cable projects is good, but still limited. Yet there is a need for a proper testing practice. Due to limited operational experience, various aspects remain to be studied. This paper focuses on electrical testing of electrical insulation, the application of power laws and the length effect. These issues are yet to be resolved, but the paper discusses their background and uncertainties. This may give direction to the ongoing studies in order to assure quality of HTS.DC systems, Energy conversion & StorageEEMCS - Genera