BackgroundPhysical inactivity remains an under-researched field in terms of studying burden of disease at provincial level, and no studies have examined the effects of inactivity on life expectancy (LE) in China. The purpose of this study was to estimate mortality risk and LE effects associated with insufficient levels of physical activity in Jiangxi province.Methods/FindingsPrevalence of risk factors and mortality counts were extracted from Chronic Diseases and Risk Factors Surveillance Survey (CDRFSS) and Disease Surveillance Points system (DSP), respectively. Insufficient physical activity (IPA) was defined as less than 150 minutes of moderate-intensity physical activity or 60 minutes of vigorous-intensity physical activity per week, accumulated across work, home, transport and discretionary domains. Population-attributable fractions (PAF) were used to calculate the mortality attributable to risk factors, and life table methods were used to estimate the LE gains and LE shifts. Monte Carlo simulation techniques were used for uncertainty analysis. Overall, 5 885 (95% uncertainly interval (UI), 5 047–6 506) and 8 578 (95% UI, 8 227–9 789) deaths in Jiangxi province were attributable to IPA in 2007 and 2010, respectively. The LE gains for elimination of attributable deaths were 0.68 (95% UI, 0.61–076) in 2007, and increased to 0.91 (95% UI, 0.81–1.10) in 2010. If the prevalence of IPA in 2010 had been decreased by 50% or 30%, 3 678 (95% UI, 3 220–4 229) or 2 090 (95% UI, 1 771–2 533) deaths would be avoided, and 0.40 (95% UI, 0.34–0.53) or 0.23 (95% UI, 0.16–0.31) years of LE gained, respectively.ConclusionsAdults in Jiangxi province of China have a high and increasing prevalence of IPA. Due to the deaths and potential LE gains associated with IPA, there is an urgent need to promote physical activity, one of the most modifiable risk factors, within China's health care reform agenda.

No abstract

No abstract

Based on a type of three-dimensional slice model of a brush seal combined with the commercial CFD software FLUENT, the study calculated the leakage flow of the brush seal. The aerodynamic forces applied on upstream and downstream bristles are analyzed and reduced to a smaller amount of point forces for analysis convenience. The frictional coefficient between the bristle material Haynes 25 and rotor material ICrMMnMNi are tested. Tip forces including normal reaction and frictional forces caused by aerodynamic forces are quantitatively investigated under conditions with and without frictions using the torque balance principle and nonlinear beam theory (by ANSYS simulations), respectively. Torques, frictional heats, and the temperature distributions of the rotor and bristle pack are studied further. Details and characteristics of the flow and temperature distributions inside the bristle pack are presented. In the experiments, besides traditional tests, such as leakage and torque tests, an infrared camera is employed to capture temperature distributions at the interface of the rotor, bristle pack and nearby zones under various pressure differentials and rotation speeds. The three-dimensional slice model is firstly verified by calculating the leakages, torques and temperature distributions of the brush seal and confirmed via experimentation. The influence of various frictional coefficients and pressure differentials on tip forces, torque and temperature distributions are also examined.

Without a coil and a gearbox, an ultrasonic motor has an important application in space engineering and so forth with advantages of light weight, small volume, less electromagnetic radiation, fast dynamic response, and high energy density. However, the obvious friction and wear between the stator and the friction material (as a part of the shaft assembly) restrict the reliability and life time of the ultrasonic motor. In this paper, a life test of ultrasonic motors is designed and carried out for 3041.7 h, and the eight motors are divided into four groups with torque loads of 0.03 Nm, 0.09 Nm, 0.16 Nm, and 0.21 Nm in the test. The evolution characteristics of the displacement frequency response and the wear on the stator contact surface under different torque loads during the wear process are analyzed. Some start-up problems occur during the early time in the life test are found and explained based on a meshing effect between the stator and the friction material, and some targeted suggestions are proposed to overcome the problems. The study can help to understand the wear failure mechanism and characteristics of ultrasonic motors.