Actuators for smart applications

Actuator manufacturers are developing promising technologies\ud which meet high requirements in performance, weight and\ud power consumption. Conventionally, actuators are characterized\ud by their displacement and load performance. This hides the\ud dynamic aspects of those actuation solutions. Work per weight\ud performed by an actuation mechanism and the time needed to\ud develop this mechanical energy are by far more relevant figures.\ud Based on these figures, a selection process was developed.\ud With time and energy constraints, it highlights the most\ud weight efficient actuators. This process has been applied to the\ud Gurney flap technology used as a morphing concept for rotorblades.\ud Three control schemes were considered and simulations\ud were performed to investigate the mechanical work required. It\ud brought forward piezoelectric stack actuators as the most effective\ud solution in the case of an actively controlled rotorblade. The\ud generic nature of the procedure allows to use it for a wide range\ud of applications

Development of a multigrid finite difference solver for benchmark permeability analysis

A finite difference solver, dedicated to flow around fibre architectures is currently being developed. The complexity of the internal geometry of textile reinforcements results in extreme computation times, or inaccurate solutions. A compromise between the two is found by implementing a multigrid algorithm and analytical solutions at the coarsest level of discretisation. Hence, the computational load of the solver is drastically reduced.\ud This paper discusses the main features of the 3D multigrid algorithm implemented as well as the implementation of the analytical solution in the finite difference scheme. The first tests of the solver on the permeability benchmark lithographic reference geometry are discussed.\ud Several tests were performed to assess the accuracy and the reduction in calculation time. The methods prove to be both accurate and efficient. However, the code is developed in Matlab© and hence is relatively slow. A C++ code is currently under development to achieve acceptable calculation times

Geometric Optimisation of Hinge-less Deployment System for an Active Rotorblade

The Green Rotorcraft project (part of Clean Sky JTI) is\ud studying the Gurney flap as a demonstrator of a smart adaptive\ud rotorblade. Deployment systems for the Gurney flap need to\ud sustain large centrifugal loads and vibrations while maintaining\ud precisely the displacement under aerodynamic loading. Designing\ud such a mechanism relies on both the actuation technology\ud and the link which transmits motion to the control surface. Flexible\ud beams and piezoelectric patch actuators have been chosen as\ud components to design this mechanism. Flexible beams are providing\ud an hinge-less robust structure onto which the piezoelectric\ud actuators are bonded. A candidate topology is determined\ud by investigating the compliance of a simple wire structure with\ud beam elements. A parametrized finite element model is then built\ud and optimized for displacement and force through surrogate optimization.\ud The whole process does not requires many finite element\ud analyses and quickly converge to an optimized mechanism

Vibration Based Damage Identification in a Composite T-Beam Utilising Low Cost Integrated Actuators and Sensors

The development of integrated measurement systems for composite structures is\ud urged by the fact that a Structural Health Monitoring environment requires these systems to become an integral part of the structure. The feasibility of using low cost piezoelectric diaphragms for dynamic characterisation and vibration based damage identification in a composite T-beam structure is demonstrated. The dynamic behaviour is analysed by applying these basic electronic sound components for actuation and sensing. Impact induced damage at the skin-stiffener connection is detected and localized by applying the MSE-DI algorithm on the measured bending strain mode shapes

Attrition-enhanced total resolution leads to homochiral families of amino acid derivatives

The total resolution of five structurally similar racemizable amino acid derivatives, three of which have racemic crystal structures, was performed simultaneously. By enantioselective incorporation in an amino acid derivative that forms a conglomerate the other four were deracemized on attrition-induced grinding. The outcome of the resolution was random (R) or (S), but all compounds had the same absolute configuration and high enantiomeric purities.

Caenorhabditis elegans as a model system for studying drug induced mitochondrial toxicity

Today HIV-1 infection is recognized as a chronic disease with obligatory lifelong treatment to keep viral titers below detectable levels. The continuous intake of antiretroviral drugs however, leads to severe and even life-threatening side effects, supposedly by the deleterious impact of nucleoside-analogue type compounds on the functioning of the mitochondrial DNA polymerase. For detailed investigation of the yet partially understood underlying mechanisms, the availability of a versatile model system is crucial. We therefore set out to develop the use of Caenorhabditis elegansto study drug induced mitochondrial toxicity. Using a combination of molecular-biological and functional assays, combined with a quantitative analysis of mitochondrial network morphology, we conclude that anti-retroviral drugs with similar working mechanisms can be classified into distinct groups based on their effects on mitochondrial morphology and biochemistry. Additionally we show that mitochondrial toxicity of antiretroviral drugs cannot be exclusively attributed to interference with the mitochondrial DNA polymerase

Geometrical optimization of a hingeless deployment system for an active rotor blade

Deployment systems for the Gurney flap need to sustain large centrifugal loads and vibrations while maintaining precisely the displacement under aerodynamic loading. Designing such a mechanism relies on both the actuation technology and the link that transmits motion to the control surface. Flexible beams and piezoelectric patch actuators have been chosen as components to design this mechanism. Flexible beams provide a hingeless robust structure onto which the piezoelectric actuators are bonded. A candidate topology is determined by investigating the compliance of a simple wire structure with beam elements. A parameterized finite element model is then built and optimized for displacement and force through surrogate optimizatio

Stochastic programming for multiple-leg network revenue management

Airline seat inventory control is a very profitable tool in the airline industry. Mathematical programming models provide booking limits or bid-prices for all itineraries and fare classes based on demand forecasts. But the actual revenue generated in the booking process fails to meet expectations. Simple deterministic models based on expected demand generate better revenue than more advanced probabilistic models. Recently suggested models put even more effort into demand forecasting. We will show that the dynamic booking process rather than the demand forecasts needs to be addressed. In particular the nesting strategies applied in booking control will counter-effect the profitability of advanced estimation of booking limits and bid-prices

Поліваріантний вплив біоактивної води Нафтуся на секрецію шлунка і пошкодження його слизової за умов перев’язки воротаря у щурів

Употребление крысами-самцами в течении 10-11 дней биоактивной воды Нафтуся вызывает в 72% случаев увеличение секреции кислоты желудком в условиях лигирования привратника. У 17% крыс кислотообразование не отличается от такового у контрольных животных, употреблявших водопроводную воду, а у 11% крыс констатирован кислотоингибиторный эффект биоактивной воды Нафтуся. Обнаружена инверсная связь между ацидогенезом и выделением гастрина в кровь и полость желудка, а также выраженностью язвенных повреждений его слизистой.The use rats-males in a flow 10-11 days of bioactive water Naftussya cause in 72% cases increase of secretion of acid by stomach in the conditions of ligating of pylorus. For 17% rats acid secretion does not differ from such for control animals, using a tapwater, and for 11% rats the inhibiting effect is established. Found out inverse relationship between acid secretion and secretion of gastrin in blood and cavity of stomach, and also expressed of ulcerous damages to his mucous membrane