Rolling-element fatigue life of AMS 5749 corrosion resistant, high temperature bearing steel

The rolling element fatigue lives of AMS 5749 and AISI M-50 were compared in tests run in the five ball fatigue tester and the rolling contact fatigue tester. The effects of double vacuum melting and retained austenite on the life of AMS 5749 were determined in five ball fatigue tests. The double vacuum melting process consisted of induction vacuum melting followed by vacuum arc remelting (VIM-VAR). In the five ball tests, VIM-VAR AMS 5749 gave lives at least six times that of VIM-VAR AISI M-50. Similar tests in the rolling contact fatigue tester showed no significant difference in the lives of the two materials. The rolling element fatigue life of VIM-VAR AMS 5749 was at least 14 times that of vacuum induction melted AMS 5749. A trend toward increased rolling element fatigue life with decreased retained austenite is apparent, but the confidence that all experimental differences are significant is not great

Effect of double vacuum melting and retained austenite on rolling-element fatigue life of AMS 5749 bearing steel

AMS 5749 steel combines the tempering, hot hardness, and hardness retention characteristics of AISI M-50 steel with the corrosion and oxidation resistance of AISI 440C stainless steel. The five-ball fatigue tester was used to evaluate the rolling-element fatigue life of AMS 5749. Double vacuum melting (vacuum induction melting plus vacuum arc remelting, VIM-VAR) produced AMS 5749 material with a rolling-element fatigue life at least 14 times that of vacuum induction melting alone. The VIM-VAR AMS 5749 steel balls gave lives from 6 to 12 times greater than VIM-VAR AISI M-50 steel balls. The highest level of retained austenite, 14.6 percent, was significantly detrimental to rolling-element fatigue life relative to the intermediate level of 11.1 percent

Plus ça change: The Coalition Government and Trade unions

One of the first announcements made by the majority Conservative government on coming to power in the UK in May 2015 was in relation to proposed legislation on trade unions. The newly appointed Business Secretary Sajid Javid stated on the BBC Today Programme that ‘We've already made clear, in terms of strike laws, that there will be some significant changes... it will be a priority of ours. We need to update our strike laws. We've never hidden away the changes we want to make. I think it's essential to make these changes’ (BBC News 2015). At first sight, this might suggest that the return to a Conservative majority government signalled a significant change in the way relationships were to be structured with trade unions, reflective of the significant legislative attacks on trade unions under the Thatcher and Major Conservative administrations of the 1980s and 1990s

Does landscape-scale conservation management enhance the provision of ecosystem services?

Biodiversity conservation approaches are increasingly being implemented at the landscape-scale to support the maintenance of metapopulations and metacommunities. However, the impact of such interventions on the provision of ecosystem services is less well defined. Here we examine the potential impacts of landscape-scale conservation initiatives on ecosystem services, through analysis of five case study areas in England and Wales. The provision of multiple ecosystem services was projected according to current management plans and compared with a baseline scenario. Multicriteria analysis indicated that in most cases landscape-scale approaches lead to an overall increase in service provision. Consistent increases were projected in carbon storage, recreation and aesthetic value, as well as biodiversity value. However, most study areas provided evidence of trade-offs, particularly between provisioning services and other types of service. Results differed markedly between study areas, highlighting the importance of local context. These results suggest that landscape-scale conservation approaches are likely to be effective in increasing ecosystem service provision, but also indicate that associated costs can be significant, particularly in lowland areas

Aerodynamic characteristics of a large-scale V/STOL transport model with tandem lift fans mounted at mid-semispan of the wing

Aerodynamic characteristics of V/STOL transport model with tandem lift fans mounted at mid-semispan of win

Higher comfort temperature preferences for anthropometrically matched Chinese and Japanese versus White-Western-Middle-European individuals using a personal comfort / cooling system

Purpose: To investigate potential differences in preferred Personal Comfort Systems (PCS) settings of Japanese and Han-Chinese versus white-western-middle-Europeans. Method: A series of five experiments with similar methodology is reported that allowed participants to self-select their preferred PCS outlet air temperature in a warm controlled climatic chamber setup with and without solar radiation. Test groups were matched for age, height, weight, body-surface-area and body-mass-index to remove the influence of these confounding factors on the results. Participants were first exposed to solar radiation (exp-1-4; simulating glazed building without proper shading or a car) before starting to control the outlet temperature of the PCS, or (exp-5, simulating warm building) were exposed to a warm room temperature and immediately could control the PCS. Ethnicity effects were studied through the chosen preferred PCS outlet temperatures and the microclimate temperature close to the participants’ chest. Results: In all experiments, Asian groups selected a PCS outlet temperature significantly higher, on average by 5 °C, leading to a 1.9 °C higher microclimate temperature at chest level. While absolute selected temperatures of the PCS differed between experiments, related to different designs of the PCS and climate conditions, no interaction between ethnicity and experiment was present. Conclusions: Despite removing important confounding factors that could explain earlier observed differences between Asian and white western middle-European ethnicities tested, a substantial, consistently higher thermal preference temperature of the PCS was found in the two Asian groups. This has implications for the design parameters of PCS for use in offices or air-conditioning systems in cars

The SKA Particle Array Prototype: The First Particle Detector at the Murchison Radio-astronomy Observatory

We report on the design, deployment, and first results from a scintillation detector deployed at the Murchison Radio-astronomy Observatory (MRO). The detector is a prototype for a larger array -- the Square Kilometre Array Particle Array (SKAPA) -- planned to allow the radio-detection of cosmic rays with the Murchison Widefield Array and the low-frequency component of the Square Kilometre Array. The prototype design has been driven by stringent limits on radio emissions at the MRO, and to ensure survivability in a desert environment. Using data taken from Nov.\ 2018 to Feb.\ 2019, we characterize the detector response while accounting for the effects of temperature fluctuations, and calibrate the sensitivity of the prototype detector to through-going muons. This verifies the feasibility of cosmic ray detection at the MRO. We then estimate the required parameters of a planned array of eight such detectors to be used to trigger radio observations by the Murchison Widefield Array.Comment: 17 pages, 14 figures, 3 table

Designing for comfort in shared and automated vehicles (SAV): a conceptual framework

To date, automotive design and research is heavily biased towards the driver. However, with the rapid advance of vehicle automation, the driving task will increasingly being taken over by a machine. Automation by itself, however, will not be able to tackle the transport challenges we are facing and the need for shared mobility is now widely recognized. Future mobility solutions are therefore expected to consist of Shared and Automated Vehicles (SAV). This means that the passenger experience will take center stage in the design of future road vehicles. Whereas at first sight this may not appear to be different to the experience in other modes of transport, automation and shared mobility introduce different psychological, physical and physiological challenges. These are related to the fact that the occupant is no longer in control, has to put his or her life in the hands of a computer, while at the same time expects such future vehicles to render travel time more efficient or pleasurable and engage in so-called non-driving related tasks. Taking inspiration from work conducted in the field of aircraft passenger comfort experience, we discuss major comfort factors in the context of SAV and highlight both similarities and differences between transport modes. We present a human centered design framework to assist both the research agenda and the development of safe, usable, comfortable, and desirable future mobility solutions