440 research outputs found
Solar cell research, phase 2 Semiannual report
Radiation effects on properties of lithium solar cell
4D microstructural and electrochemical characterization of dissimilar metal corrosion in naval structural Joints
Dissimilar metal corrosion in aircraft and naval structures has proven to be a persistent challenge. Decades of research in the area have shown that such complex contact surfaces are subject to a combination of corrosive environments and mechanical loads. Hence, this multi-faceted problem must be understood from electrochemical, microstructural and mechanical standpoints to comprehensively understand corrosion damage in these systems.
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Competition of stress corrosion crack branches observed in-situ using time-lapse 3D x-ray synchrotron computed tomography
The progress of a stress corrosion crack in a sensitized AA7075 alloy was studied by in-situ x-ray synchrotron computed tomography. A load was applied to a pre-cracked specimen inside an environmental cell containing moist air and the propagation of the stress corrosion crack was observed. Measurements from the 3D image of the crack have already been shown to provide better quantification compared to observations of the crack from the outer surface. In this paper we study in detail the progress of the stress corrosion crack as it propagates through the material. We reveal how the formation of metal ligaments occurs and the competition of the âmainâ crack and its branches. We have visualized these features to show the complexity of the local variation in crack morphology in a way that brings new insight into the interaction of the stress corrosion crack with the microstructure of the material
Please mind the gap: studentsâ perspectives of the transition in academic skills between A-level and degree level geography
This paper explores first-year undergraduatesâ perceptions of the transition from studying geography at pre-university level to studying for a degree. This move is the largest step students make in their education, and the debate about it in the UK has been reignited due to the governmentâs planned changes to A-level geography. However, missing from most of this debate is an appreciation of the way in which geography students themselves perceive their transition to university. This paper begins to rectify this absence. Using student insights, we show that their main concern is acquiring the higher level skills required for university learning
Front instabilities in evaporatively dewetting nanofluids
Various experimental settings that involve drying solutions or suspensions of
nanoparticles -- often called nanofluids -- have recently been used to produce
structured nanoparticle layers. In addition to the formation of polygonal
networks and spinodal-like patterns, the occurrence of branched structures has
been reported. After reviewing the experimental results we use a modified
version of the Monte Carlo model first introduced by Rabani et al. [Nature 426,
271 (2003)] to study structure formation in evaporating films of nanoparticle
solutions for the case that all structuring is driven by the interplay of
evaporating solvent and diffusing nanoparticles.
After introducing the model and its general behavior we focus on receding
dewetting fronts which are initially straight but develop a transverse
fingering instability. We analyze the dependence of the characteristics of the
resulting branching patterns on the driving chemical potential, the mobility
and concentration of the nanoparticles, and the interaction strength between
liquid and nanoparticles. This allows us to understand the underlying
instability mechanism.Comment: 35 pages, 28 figure
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