Temperature sensitive controller performance of MR dampers

Magnetorheological (MR) dampers can experience large temperature changes as a result of heating caused by energy dissipation, but control systems are often designed without consideration of this fact. Furthermore, due to the highly nonlinear behavior of MR dampers, many control strategies have been proposed and it is difficult to determine which is the most effective. This paper aims to address these issues through a numerical and experimental study of an MR mass isolator subject to temperature variation. A dynamic temperature dependant model of an MR damper is first developed and validated. Control system experiments are then performed using hardware-in-the-loopsimulations. Proportional, PID, gain scheduling, and on/off control strategies are found to be equally affected by temperature variation. Using simulations incorporating the temperature dependant MR damper model, it is shown that this is largely due to a change in fluid viscosity and the associated movement of the lower clipped optimal' control bound. This zero-volts condition determines how close any controller can perform to the ideal semiactive case, thus all types of controller are affected. In terms of relative performance, proportional and PID controllers perform equally well and outperform the on/off and gain scheduling strategies. Gain scheduling methods are superior to on/off control

Magnetorheological landing gear: 2. Validation using experimental data

Aircraft landing gears are subjected to a wide range of excitation conditions with conflicting damping requirements. A novel solution to this problem is to implement semi-active damping using magnetorheological (MR) fluids. In part 1 of this contribution, a methodology was developed that enables the geometry of a flow mode MR valve to be optimized within the constraints of an existing passive landing gear. The device was designed to be optimal in terms of its impact performance, which was demonstrated using numerical simulations of the complete landing gear system. To perform the simulations, assumptions were made regarding some of the parameters used in the MR shock strut model. In particular, the MR fluid's yield stress, viscosity, and bulk modulus properties were not known accurately. Therefore, the present contribution aims to validate these parameters experimentally, via the manufacture and testing of an MR shock strut. The gas exponent, which is used to model the shock strut's nonlinear stiffness, is also investigated. In general, it is shown that MR fluid property data at high shear rates are required in order to accurately predict performance prior to device manufacture. Furthermore, the study illustrates how fluid compressibility can have a significant influence on the device time constant, and hence on potential control strategies

BICCO-Net II. Final report to the Biological Impacts of Climate Change Observation Network (BICCO-Net) Steering Group

• BICCO-Net Phase II presents the most comprehensive single assessment of climate change impacts on UK biodiversity to date. • The results provide a valuable resource for the CCRA 2018, future LWEC report cards, the National Adaptation Programme and other policy-relevant initiatives linked to climate change impacts on biodiversity

Climate change and water in the UK : past changes and future prospects: a climate change report card for water: Working technical paper

Climate change is expected to modify rainfall, temperatures and catchment hydrological responses across the world, and adapting to these water-related changes is a pressing challenge. This paper reviews the impact of climate change on water in the UK and looks at projections of future change. The natural variability of the UK climate makes change hard to detect; only historical increases in air temperature can be attributed to climate change, but over the last fifty years more winter rainfall has been falling in intense events. Future changes in rainfall and evapotranspiration could lead to changed flow regimes and impacts on water quality, aquatic ecosystems and the water available for use by people. Summer flows may decrease on average, but floods may become larger and more frequent. Water quality may decline as a result of higher water temperatures, lower river flows and increased algal blooms. Water demand may increase in response to higher summer temperatures, placing additional pressure on water resources. These changes affect many parts of everyday life, emphasising the importance of long-term adaptation that takes these possible changes into account

Survey of antipsychotic medication curriculum content in Australian university nursing programmes

Antipsychotic medication has long been one of the first-line interventions for people with serious mental illness, with outcomes including reductions in symptoms and relapse rates. More recently, however, questions have been raised about the efficacy of antipsychotic medications, especially in light of their side-effect profile. Such questions have implications for the nurses administering antipsychotic medications, particularly in relation to their knowledge of the antipsychotic medication, its efficacy, and side-effect profile. Also important is the education of nursing students about antipsychotic medications, their use, and management. The present study reports findings of research that explored current curriculum content concerning psychopharmacological treatment in Australian undergraduate and postgraduate nursing programmes. Using a survey design, the research examined the content and modes of delivery of this content to gauge how well students are prepared for administering antipsychotic medication to people with serious mental illness. Findings of the research suggested the need for improvement in preparing nursing students to administer antipsychotic medication, including indications, contraindications, as well as recognition and management of side-effects