The effect of temperature on wear and friction of a high strength steel in fretting

This paper investigates the effect of temperature (between 24 °C and 450 °C) on the wear rate and friction coefficient of a high strength alloy steel (Super-CMV) in gross sliding fretting in air. It was found that whilst there was significant loss of material from the contact during fretting at room temperature, the overall loss of material from the contact had become negative even with a modest increase in temperature to 85 °C. At temperatures greater than 85 °C, negative wear was maintained, with the coefficient of friction dropping monotonically with increasing temperature up to 450 °C. It is proposed that the changes in wear rate and friction coefficient were due to changes in the way that the oxide particles sintered to form a protective debris bed, with sintering of the oxide debris particles at these low temperatures being promoted by the nano-scale at which the oxide debris is formed

MIGHTEE: multi-wavelength counterparts in the COSMOS field

In this paper we combine the Early Science radio continuum data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey, with optical and near-infrared data and release the cross-matched catalogues. The radio data used in this work covers 0.86 deg2 of the COSMOS field, reaches a thermal noise of 1.7 μJy/beam and contains 6102 radio components. We visually inspect and cross-match the radio sample with optical and near-infrared data from the Hyper Suprime-Cam (HSC) and UltraVISTA surveys. This allows the properties of active galactic nuclei and star-forming populations of galaxies to be probed out to z≈5. Additionally, we use the likelihood ratio method to automatically cross-match the radio and optical catalogues and compare this to the visually cross-matched catalogue. We find that 94 per cent of our radio source catalogue can be matched with this method, with a reliability of 95 per cent. We proceed to show that visual classification will still remain an essential process for the cross-matching of complex and extended radio sources. In the near future, the MIGHTEE survey will be expanded in area to cover a total of ∼20~deg2; thus the combination of automated and visual identification will be critical. We compare redshift distribution of SFG and AGN to the SKADS and T-RECS simulations and find more AGN than predicted at z∼1

MIGHTEE : are giant radio galaxies more common than we thought?

Please read abstract in the article.DATA AVAILABILITY: The data underlying this article were accessed from the South African Radio Astronomy Observatory (SARAO; www.ska.ac.za).The National Research Foundation (NRF), SARAO. MP, SMR, the UK Science and Technology Facilities Council, the Oxford Hintze Centre for Astrophysical Surveys that is funded through generous support from the Hintze Family Charitable Foundation, the Rhodes University Centre for Radio Astronomy Techniques and Technologies (RATT), the European Union’s Horizon 2020 research and innovation program under a Marie Skłodowska-Curie grant, the Inter-University Institute for Data Intensive Astronomy (IDIA), the South African Research Chairs Initiative of the NRF, the Glasstone Foundation, the Italian Ministry of Foreign Affairs and International Cooperation, the Science and Technology Foundation (FCT, Portugal), the Science and Technology Facilities Council (STFC), the South African Astronomical Observatory, the Bundesministerium für Bildung und Forschung (BMBF), the Inter-University Institute for Data Intensive Astronomy (IDIA) and the ERC-Stg DRANOEL.https://academic.oup.com/mnrashj2022Physic