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BackgroundThis intervention aimed to ascertain whether a low-cost, accessible, physical activity and nutrition program could improve physical activity and nutrition behaviours of insufficiently active 60–70 year olds residing in Perth, Australia.MethodsA 6-month home-based randomised controlled trial was conducted on 478 older adults (intervention, n = 248; control, n = 230) of low to medium socioeconomic status. Both intervention and control groups completed postal questionnaires at baseline and post-program, but only the intervention participants received project materials. A modified fat and fibre questionnaire measured nutritional behaviours, whereas physical activity was measured using the International Physical Activity Questionnaire. Generalised estimating equation models were used to assess the repeated outcomes over both time points.ResultsThe final sample consisted of 176 intervention participants and 199 controls (response rate 78.5%) with complete data. After controlling for demographic and other confounding factors, the intervention group demonstrated increased participation in strength exercise (p < 0.001), walking (p = 0.029) and vigorous activity (p = 0.015), together with significant reduction in mean sitting time (p < 0.001) relative to controls. Improvements in nutritional behaviours for the intervention group were also evident in terms of fat avoidance (p < 0.001), fat intake (p = 0.021) and prevalence of frequent fruit intake (p = 0.008).ConclusionsA minimal contact, low-cost and home-based physical activity program can positively influence seniors’ physical activity and nutrition behaviours.Trial registrationanzctr.org.au Identifier: ACTRN12609000735257

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Downsized spark ignition engines have the benefit of high thermal efficiency; however, severe engine knock is a challenge. Ethanol, a renewable gasoline alternative, has a much higher octane rating and heat of vaporization than conventional gasoline, therefore, ethanol fuels are one of the options to prevent knock in downsized engines. However, the performance of ethanol blends in modern downsized engines, and the contributions of the research octane number (RON), octane sensitivity (defined as RON-MON) and charge cooling to suppressing engine knock are not fully understood. In this study, eight fuels were designed and tested, including four splash blended ethanol fuels (10 vol.%, 20 vol.%, 30 vol.% and 85 vol.% ethanol, referred to as E10, E20, E30 and E85), one match blended fuel (E0-MB) with no ethanol content but the same octane rating as E30, and three fuels (F1-F3) with different combinations of RON and octane sensitivity. The experiments were conducted in a single-cylinder direct-injection spark ignition (DISI) research engine. Load and spark timing sweep tests at 1800 rpm were carried out for E10-E85 to assess the combustion performance of these ethanol blends. In order to investigate the impact of charge cooling on combustion characteristics, the results of the load sweep for E0-MB were compared to those of E30. Load sweep tests were also carried out for F1-F3 to understand the impacts of RON and octane sensitivity on suppressing engine knock. The results showed that at the knock-limited engine loads, splash blended ethanol fuels with a higher ethanol percentage enabled higher engine thermal efficiency through allowing more advanced combustion phasing and less fuel enrichment for limiting the exhaust gas temperature under the upper limit of 850 °C, which was due to the synergic effects of higher RON and octane sensitivity, as well as better charge cooling. In comparison with octane sensitivity, RON was a more significant factor in 2 improving engine thermal efficiency. Charge cooling reduced engine knock tendency through lowering the unburned gas temperature.