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Structural and spatial aspects of cell degradation are studied using a combination of diffraction-and imaging-based tools applying laboratory X-rays, neutron scattering and synchrotron radiation with electrochemical and thermal characterization. Experimental characterization is carried out on cylindrical cells of 21700-type, where four regimes of cell degradation are identified, which are supplemented by an increased cell resistance and surface temperature during cell operation. The amount of intercalated lithium in the fully charged anodes in the fresh and aged states is determined by ex situ X-ray diffraction radiography and in situ X-ray diffraction computed tomography. The qualitatively similar character of the results revealed a loss of active lithium along with the development of a complex heterogeneous distribution over the electrode stripe.

Measurements with widefield radio interferometers often include the near-infinite gradient between the sky and the horizon. This causes aliasing inherent to the measurement itself and is purely a consequence of the Fourier basis. For this reason, the horizon is often attenuated by the instrumental beam down to levels deemed inconsequential. However, this effect is enhanced via our own Galactic plane as it sets over the course of a night. We show all-sky simulations of the Galactic plane setting in a low-frequency radio interferometer in detail for the first time. We then apply these simulations to the Murchison Widefield Array to show that a beam attenuation of 0.1% is not sufficient in some precision science cases. We determine that the noise statistics of the residual data image are drastically more Gaussian with aliasing removal, and explore consequences in simulation for cataloging of extragalactic sources and 21 cm Epoch of Reionization detection via the power spectrum.

Searching for development paths and suitable educational policies, postcolonial governments often turned to the experiences of other countries and sought to adapt these to their own contexts. Research on such processes has largely neglected the resulting entanglements between postcolonial and European socialist countries, and between different postcolonial countries. This gap in research is addressed in this article by tracing a world-spanning history of educational transfers that has its origins in the Workers' Faculties of the early Soviet Union. Workers' Faculties were established with two goals: quickly channelling members of formerly disadvantaged social groups into higher education by providing university-preparatory education to workers and peasants; and providing suitably educated cadres for the development of a socialist society. After World War 2, institutions drawing on the Soviet experiences and combining these two goals were established in European, Asian, Latin American, and African countries. Tracing the processes of transfers and local interpretations of these institutions gives insights into an entangled history of postcolonial and socialist education, but also into how tensions between education as a means to provide social equality and education as a tool for (socialist) development played out in various national contexts.

A full series of variously lithiated graphite anodes material LixC6 (0

Efficient infiltration of a mesoporous titania matrix with conducting organic polymers or small molecules is one key challenge to overcome for hybrid photovoltaic devices. A quantitative analysis of the backfilling efficiency with time-of-flight grazing incidence small-angle neutron scattering (ToF-GISANS) and scanning electron microscopy (SEM) measurements is presented. Differences in the morphology due to the backfilling of mesoporous titania thin films are compared for the macromolecule poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) and the heavy-element containing small molecule 2-pinacolboronate-3-phenylphenanthro[9,10-b]tellurophene (PhenTe-BPinPh). Hence, a 1.7 times higher backfilling efficiency of almost 70% is achieved for the small molecule PhenTe-BPinPh compared with the polymer PTB7-Th despite sharing the same volumetric mass density. The precise characterization of structural changes due to backfilling reveals that the volumetric density of backfilled materials plays a minor role in obtaining good backfilling efficiencies and interfaces with large surface contact.

The dissolution of nano-sized Ni3Al-based γ′ precipitates was investigated in the newly developed polycrystalline nickel-based VDM® Alloy 780 at the surface and in the bulk region with in-situ lab-source and synchrotron X-ray diffraction. These studies are important in obtaining a deeper understanding of the strengthening mechanism responsible for the stability and long service lives of such superalloys. We found that the dissolution behavior of the γ′ phase is very similar at the surface and in the bulk region, but small deviations were detected. The dissolution of γ′ starts at around 800 °C and no γ′ was found at temperatures exceeding 970 °C. As a result, the elements Al and Nb, which were bound in the γ′ phase, dissolved into the γ matrix and strongly increased the γ lattice parameter, as their atomic size is larger than the γ-forming elements Ni, Co, and Cr. However, this effect was suppressed in the surface area. A second matrix γ phase was detected at the same temperature range as that of the dissolution of the γ′ phase in the lab-source XRD measurements. The newly formed γ-2 phase had a smaller lattice parameter than that of the initial γ matrix. We propose that the γ-2 matrix phase is a result of high-temperature surface oxidation, which consumes, among other elements, Al and Nb and, therefore, leads to the smaller γ lattice parameter.

Worker's Faculties, which have been widespread in the Soviet Union up until 1941, combined the two goals of preparing adult workers and peasants for university entrance through the provision of general education, as well as creating a new socialist intelligentsia from among these groups. After World War II, Workers' Faculties were also established in postcolonial countries. Based on case studies in Vietnam, Cuba, and Mozambique, we argue that corresponding transfer processes were largely driven by local actors in the respective countries and that these institutions were regarded as suitable instruments in solving problems particular to postcolonial contexts.