Standing wave acoustic levitation transportation technique has been widely used in many research areas. In this work, two Langevin-type piezoelectric transducers’ central lines are mounted at a certain angle which is...
Standing wave acoustic levitation transportation technique has been widely used in many research areas. In this work, two Langevin-type piezoelectric transducers’ central lines are mounted at a certain angle which is named a contraposition transducer array. The levitator developed in this work is constructed using the array and a reflector. Accordingly, a standing wave acoustic field is formed to levitate and transport particles by optimizing the angle between central lines of the two transducers, the distance between the two transducers’ output and their reflectors, the exciting phase differential on the two transducers. In this standing wave acoustic field, the trapped objects can be levitated and transported by modulating the exciting phase difference of the two transducers. In this work, the locations of the levitated particles are acquired by a high speed video camera and are clarified using the Hough Circle algorithm. The experiments carried out by the authors have demonstrated the effects of the levitator’s structure parameters (including the angle between central lines of the two transducers, the distance between the two transducers’ output and the reflector) on the transportation trajectory.
In this work, a standing wave acoustic field formed by using two contraposition transducers is used to classify the mixed powder. COMSOL-based simulations reveal the influence of the factors on the drop trajectories o...
In this work, a standing wave acoustic field formed by using two contraposition transducers is used to classify the mixed powder. COMSOL-based simulations reveal the influence of the factors on the drop trajectories of the particles within an acoustic field. Then the experiments are carried out to demonstrate those obtained using COMSOL-based simulations. Finally, the separation experiments of the mixed powder of iron and dioxide silica are achieved, including the mixed powder both in the same diameter and the different diameter respectively.
This paper describes the BAPAMAN（Binary Actuated Parallel MANipulator） series of parallel manipulators that has been conceived at Laboratory of robotics and mechatronics（LARM）. Basic common characteristics of BAPA...
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This paper describes the BAPAMAN（Binary Actuated Parallel MANipulator） series of parallel manipulators that has been conceived at Laboratory of robotics and mechatronics（LARM）. Basic common characteristics of BAPAMAN series are described. In particular, it is outlined the use of a reduced number of active degrees of freedom, the use of design solutions with flexural joints and Shape Memory Alloy（SMA） actuators for achieving miniaturization, cost reduction and easy operation features. Given the peculiarities of BAPAMAN architecture, specific experimental tests have been proposed and carried out with the aim to validate the proposed design and to evaluate the practical operation performance and the characteristics of a built prototype, in particular, in terms of operation and workspace characteristics.
This paper uses optical whispering galley modes(WGM) cavities to construct a new electrical sensing interface between prosthetic limb and the *** sensing element will detect the action potential signal in the neural m...
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This paper uses optical whispering galley modes(WGM) cavities to construct a new electrical sensing interface between prosthetic limb and the *** sensing element will detect the action potential signal in the neural membrane and the prosthetic limb will be actuated *** element is a WGM dielectric polymeric *** based optical cavities can achieve very high values of sensitivity and quality factor;thus,any minute perturbations in the morphology of the cavity can be captured and *** action potential signal will produce an applied external electric field on the dielectric cavity causing it to deform due to the electrostriction *** resulting deformation will cause WGM shifts in the transmission spectrum of the ***,the action potential or the applied electric field can be measured using these *** this paper the action potential signal will be simulated through the use of a function generator and two metal *** sensing element will be situated between these electrodes to detect the electrical signal passing *** achieved sensitivity is 27.5 pm/V in measuring the simulated action potential signal;and 0.32 pm/V.m-1 in measuring the applied electric field due to the passage of the simulated signal.
The yaw angle has a great importance in the wind turbine working. Even though most of the large turbines have yaw mechanisms, they do not have an instant response. The aerodynamic forces and torque on the blades fluct...
The yaw angle has a great importance in the wind turbine working. Even though most of the large turbines have yaw mechanisms, they do not have an instant response. The aerodynamic forces and torque on the blades fluctuate, depending on the yaw angle. The design and the numerical simulation of the wind turbine were performed with the Blade Element Momentum method in open source QBlade software. The power coefficient, torque, thrust and power output generated by wind turbine in non-yawed flow were analysed. The simulations have been performed for non-yawed flow, in rotational speed range between 2100 and 3300 rpm and wind velocity of 15 m/s. Simulations for yaw angle range have been performed between ± 60°, with 5° step at rated rotational speed of 2700 rpm. The results are presented through charts for global parameters in both non-yawed flow, and yawed flow. The effect of yaw angle on global performances of the wind turbines is more important after the value of 25° when the power output decrease with about 15% from power output in non-yawed flow. The average value of the exponent from conventional relation of power coefficient in yawed flow is 1.77 in good concordance with experimental tests.
The pumping stations are key points of water treatment plants, their performance directly affecting the serviceability of the entire water treatment system. The excessive wear of mechanical components conducts to pump...
The pumping stations are key points of water treatment plants, their performance directly affecting the serviceability of the entire water treatment system. The excessive wear of mechanical components conducts to pumping station out of service state. The deposition of thin coatings on the elements subjected to wear can generally extend the operating time of the water treatment plants. The paper analyses the failure modes of the mechanical components of the pumping stations and the existing efficient solutions for thin coating deposition to protect them from excessive wear. Consequently, an effective coating is deposited on the raw metal by Atmospheric Plasma Spraying (APS) and tribological tests are developed for an initial assessment of the anti-wear properties of the coating. The worn contact surfaces are analysed by Scanning Electron Microscopy (SEM) and the chemical composition is established by Energy-dispersive X-ray spectroscopy (EDS). The tests are still in development, revealing that the main failure modes of the coating are abrasive wear and delamination. Future research will be conducted to identify the best combination of powders for a multiple layer deposited coating with high wear resistance.
Currently, for the purposes of recorded ECG signals (electrocardiograms) interpretation, the classical methods involving analysis of geometrical properties of the recorded waveforms in time domain are used. Such an an...
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Currently, for the purposes of recorded ECG signals (electrocardiograms) interpretation, the classical methods involving analysis of geometrical properties of the recorded waveforms in time domain are used. Such an analysis consists in determining the values of parameters describing the heart rate and rhythm. However, these indicators can not be treated as an infallible criterion for diagnosis and, moreover, the limits of increasing the accuracy of ECG analysis by increasing the accuracy of determining its characteristic points have already been reached. Therefore, in the paper, for the purposes of analysis of registered ECG signals and acoustical recordings of heart work, it is proposed to use the recurrence plots and RQA analysis methods that consist in searching for the recurrence properties of the registered signals. Application of the recurrence-based methods is natural due to the cyclic character of the heart work while providing patterns characteristic for different cardiac dysfunctions supported by objective, quantitative measures will contribute to early, credible and reliable classification of cardiovascular dysfunction.
20 years after the successful ground deployment test of a (20 m)2 solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and...
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