Nickel-cadium batteries for Apollo telescope mount

The operational testing and evaluation program is presented which was conducted on 20-ampere-hour nickel-cadmium (Ni-Cd) batteries for use on the Apollo telescope mount (ATM). The test program was initiated in 1967 to determine if the batteries could meet ATM mission requirements and to determine operating characteristics and methods. The ATM system power and charging power for the Ni-Cd secondary batteries is provided by a solar array during the 58-minute daylight portion of the orbit; during the 36-minute night portion of the orbit, the Ni-Cd secondary batteries will supply ATM system power. The test results reflect battery operating characteristics and parameters relative to simulated ATM orbital test conditions. Maximum voltage, charge requirements, capacity, temperature, and cyclic characteristics are presented

Bipolar-Driven Large Magnetoresistance in Silicon

Large linear magnetoresistance (MR) in electron-injected p-type silicon at very low magnetic field is observed experimentally at room temperature. The large linear MR is induced in electron-dominated space-charge transport regime, where the magnetic field modulation of electron-to-hole density ratio controls the MR, as indicated by the magnetic field dependence of Hall coefficient in the silicon device. Contrary to the space-charge-induced MR effect in unipolar silicon device, where the large linear MR is inhomogeneity-induced, our results provide a different insight into the mechanism of large linear MR in non-magnetic semiconductors that is not based on the inhomogeneity model. This approach enables homogeneous semiconductors to exhibit large linear MR at low magnetic fields that until now has only been appearing in semiconductors with strong inhomogeneities.Comment: 23 pages, 4 figures (main text), 6 figures (supplemental material

Art of the Americas Revisited : What Does it Mean to Decolonise a Museum?

The Art of the Americas exhibition (March – July 2018) at the Max Chambers Library, University of Central Oklahoma (UCO), USA, questioned the practices of assigning cultural objects to different academic disciplines and separate museums. The exhibition brought together diverse cultural objects from North, Central and South America. Using the exhibition as a threshold and a lens, this paper opens a broader conversation on decolonising museums that challenge the knowledge-building system in academic institutions. First, Shikoh Shiraiwa, curator, revisits Art of the Americas to re-examine his motives and positionality. Secondly, Olga Zabalueva dwells on the theoretical implications and importance of constantly re-assessing decolonial efforts. Third, we both explore how ingrained racial hierarchies have crystalised in certain academic disciplines. As a result, we further elaborate on the criticality of challenging institutionalised scholarship, concluding with theoretical pursuit of cultural and socially sustainable museum practice for the future.Peer reviewe