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The electrohydrodynamic (EHD) effect ("ion wind") associated with corona discharges in air has been extensively investigated and modeled. We present a simple experiment that shows how both the magnitude and direction of EHD forces can change in such a way as to impart energy continuously to an oscillating electrostatic pendulum. The amplitude of oscillations of an electrostatic pendulum subject to EHD forces can grow approximately exponentially over a period of minutes, and we describe a qualitative theory to account for this effect, along with implications of these experiments for theories of ball lightning. [ABSTRACT FROM AUTHOR]

We report on the application of a static (dc) electric field in the plume region during the pulsed Nd doped yttrium aluminum garnet laser deposition (PLD) of tetrahedral amorphous carbon (ta-C) films in vacuum ambient (pressure=10-4–10-3 Pa), where the working pressure is exclusively due to ablation vapor. This approach is strikingly different from the plasma- or ion-beam-assisted PLD because the mean free path at this pressure is by far longer than the target to substrate distance. Thus, the electric field interacts with individual ionized species invoking ion acceleration and gas-phase reactions among different ionized species. These phenomena are clearly dependent on the laser wavelength (first, second, or third harmonic, λ=1064, 532, and 355 nm, respectively) used for the ablation. We found that the application of the electric field causes surface smoothing (the roughness decreases from about 1 to 0.4 nm) and faster deposition rate (from about 2 to 7 nm/min) for the second and third harmonics. In addition, the phenomena are less intense in the case of the first harmonic due to the low concentration of ionized species in the plume. In addition, in the case of PLD using λ=532 nm, the electric field improves the film’s density (from 2.60 to 2.95 g/cm3). The correlations found are discussed in terms of the ablated species and the deposition mechanisms of the ta-C. [ABSTRACT FROM AUTHOR]

Presents a study that examined an electrostatic precipitator to determine its salient electrical behavior, particle charging and collection characteristics for pulse powering under clean plate conditions. Background on pulse energization; Analysis of the impact and interplay of particle diffusivity and electron charging; Results and implications.

Contact bounce, high driving voltage, and poor robustness to process deviations are the main bottlenecks that limit the reliability of MEMS electrostatic switches. In this study, a variable stiffness strategy offers an optimized path to reach the closure position for the movable electrode. In the proposed method, the switching system's stiffness is low enough to reduce the driving voltage at the initial stage but increases rapidly as the movable electrode approaches the closure position for braking. Our experimental results prove that this strategy can suppress contact bounce, reduce pull-in voltage without compromising pull-in time, and also enhance robustness to process deviations, improving the overall reliability of the MEMS switches. [ABSTRACT FROM AUTHOR]

Electrostatic accelerometers have extremely high sensitivity and are ideal scientific instruments for measuring very weak acceleration. In particular, a single-sensitive-axis electrostatic accelerometer can be used for testing the equivalence principle in space. Sensitive-axis capacitances formed by axial electrodes and a cylindrical proof mass vary with the axial motion of the mass and are also affected by radial motion, which results in cross-axis coupling disturbances. A quantitative model is built to analyze the cross-axis coupling effect on the sensitive axis from the radial suspension loop, including a nonlinear model for large radial motion and a linear model for small radial motion. Frequency response simulation shows that the cross-axis coupling effect for a small signal case arises mostly in the high-frequency range. Experiments are carried out with a ground-based electrostatic accelerometer made of a single, non-rotating test cylinder, and in this case, the experimental results are utilized to verify the mathematical model. Cross-axis coupling for small signal perturbations is virtually removed if the equilibrium position of the proof mass is calibrated to the null position of the sensor cage. In addition, data post-processing can further attenuate the cross-axis coupling disturbances when dealing with large radial motion. The cross-axis coupling disturbances on both the position and the acceleration measurement signals in the sensitive axis are mostly removed in ground-based experiments. The proposed model and compensation can be extended to space equivalence principle instruments and other electrostatic accelerometers with a cylindrical proof mass. [ABSTRACT FROM AUTHOR]

Design of a transverse flux machine (TFM) with high power factor and high torque density is presented. Detailed analysis and verification of the benefit of TFMs over conventional radial flux machines, in terms of torque production capability, is described. A comprehensive investigation of the ideal torque production capability, power factor, and deviation from ideal cases is explained. Factors contributing to performance degradation are identified and a robust method is proposed to design and improve the machine performance. Simulation and experimental results are provided to validate the innovation and the robustness of the design process. [ABSTRACT FROM AUTHOR]

While the use of foil windings in transformers and air core inductors is not uncommon, their use in electric machines is just emerging. Although prototype realizations have been reported in the literature, a definitive analysis of their thermal performance is necessary to evaluate their potential for broad applications. This paper is devoted to presenting a comprehensive model for evaluating their thermal performance including loss modeling and temperature rise prediction in realistic designs. An overview of foil windings in electric machines and their advantages in improved fill factor is presented, along with experimental results that compare the ac losses and temperature distribution under identical steady-state operating conditions with a prototype round conductor coil and foil conductor coil. A lumped parameter thermal model that predicts the heat transfer behavior of the foil conductor coil is presented along with supporting experimental results. [ABSTRACT FROM AUTHOR]

In order to find the final solution the design of electrical machines usually involves different steps. In the starting stages of design procedure, some of the main variables are given data and all the others must be adopted by a proper approach. This paper proposes a method for determining the total slot number within the induction machine by approaching electromagnetic forces that leads to a particular relationship. The final solution is checked by some manufactured induction machine. [ABSTRACT FROM AUTHOR]

Some of you may remember the 1979 television series “Connections” that was written and narrated by James Burke, a British science writer. Burke’s technique was to choose a number of seemingly unrelated ideas and show how they led to developments in science and technology. This is an enjoyable business, even if some of the connections seem to be stretched at times, and led to a book by Burke. In a number of talks that I have given over the years, I have made somewhat less fanciful connections that suggest how the technologies of high vacuum and high voltage led to what used to be called “modern physics.” Today we might limit the “modern” era to the years from 1890 to 1920 that gave the first workable theories of small-scale physics. [ABSTRACT FROM AUTHOR]

In the double-drain multistate electrostatically formed nanowire transistor (MSET), the electrostatically formed conduction channel shifts laterally by properly biasing the two side gates that enclose the bulk area. This current switching mechanism enhances functionality within a single device and sets the stage for a family of integrated circuit building blocks that facilitate the implementation of ultralow-power Internet-of-Things applications. This paper establishes a conceptual framework for the MSET-based nand gate whose speed and power consumption are analyzed via TCAD simulations. [ABSTRACT FROM AUTHOR]

High sensitivity of Gravity Inertial Sensors (GIS) can be achieved with low natural frequency Ω of the proof mass (PM) that must have low level noises in the read-out system and a minimized torsion stiffness. In this article, a differential electrostatic system (DES) is proposed where both previous two conditions are met. We also consider the effect of the asymmetry γ of the DES in the GIS that is limited by the manufacturing technology of the sensor and hence making it difficult to reduce further. We propose an alternative compensation of this asymmetry by introducing additional sources of electric field. It is shown that any inaccuracy in this compensation will lead to inaccuracy of the sensor and can violates it stability. Based on open public literature, this is the first time where it is possible to ascertain the torsion stiffness reduction limits for such a sensor. [ABSTRACT FROM AUTHOR]

Existing soft actuators have persistent challenges that restrain the potential of soft robotics, highlighting a need for soft transducers that are powerful, high-speed, efficient, and robust.We describe a class of soft actuators, termed hydraulically amplified self-healing electrostatic (HASEL) actuators, which harness a mechanism that couples electrostatic and hydraulic forces to achieve a variety of actuation modes.We introduce prototypical designs of HASEL actuators and demonstrate their robust, muscle-like performance as well as their ability to repeatedly self-heal after dielectric breakdown— all using widely available materials and common fabrication techniques. A soft gripper handling delicate objects and a self-sensing artificial muscle powering a robotic arm illustrate the wide potential of HASEL actuators for next-generation soft robotic devices. [ABSTRACT FROM AUTHOR]

The chaos-based optimization algorithm (COA) is a method to optimize possibly nonlinear complex functions of several variables by chaos search. The main innovation behind the chaos-based optimization algorithm is to generate chaotic trajectories by means of nonlinear, discrete-time dynamical systems to explore the search space while looking for the global minimum of a complex criterion function. The aim of the present research is to investigate the numerical properties of the COA, both on complex optimization test-functions from the literature and on a real-world problem, to contribute to the understanding of its global-search features. In addition, the present research suggests a refinement of the original COA algorithm to improve its optimization performances. In particular, the real-world optimization problem tackled within the paper is the estimation of six electro-mechanical parameters of a model of a direct-current (DC) electrical motor. A large number of test results prove that the algorithm achieves an excellent numerical precision at a little expense in the computational complexity, which appears as extremely limited, compared to the complexity of other benchmark optimization algorithms, namely, the genetic algorithm and the simulated annealing algorithm. [ABSTRACT FROM AUTHOR]

A vertical Silicon Controlled Rectifier (VSCR) realized in a high-voltage (HV) 40 V bipolar process is proposed for electrostatic discharge (ESD) protection applications. In addition, a new method is proposed to alter the layout of the emitter regions of the parasitic vertical PNP (VPNP) bipolar transistor in the VSCR to optimize the trigger voltage and the area of the VSCR. The transmission line pulsing (TLP) measurement results show that the VSCR possesses enhanced ESD robustness compared to the conventional vertical PNP (VPNP) bipolar transistor. The new VSCR can adjust trigger voltage, holding voltage and failure current with changing the number of emitter regions. Compare to VPNP bipolar transistor, the VSCR is more suitable for 40 V bipolar process. [ABSTRACT FROM AUTHOR]

An electrostatic quadrupole doublet lens system has been designed and constructed to provide strong, mass-independent focusing of 1–3 MeV ions to a 1 µm 2 spot size. The electrostatic doublet consists of four sets of gold electrodes deposited on quartz rods that are positioned in a precision machined rigid frame. The 38 mm electrodes are fixed in a quadrupole doublet arrangement having a bore diameter of 6.35 mm. The coating process allows uniform, 360° coverage with minimal edge defects. Determined via optical interferometry, typical surface roughness is 6 nm peak to valley. Radial and coaxial alignment of the electrodes within the frame is accomplished by using a combination of rigid and adjustable mechanical supports. Axial alignment along the ion beam is accomplished via external manipulators. COMSOL Multiphysics® v5.2 and Propagate Rays and Aberrations by Matrices (PRAM) were used to simulate ion trajectories through the system. [ABSTRACT FROM AUTHOR]

Finite element analysis (FEA) has rapidly developed in the past three decades. In case of the magnetic field analysis, many researchers have proposed different electric machines by using FEA in order to achieve high efficiency, high torque density, low torque ripple, and so on. For further development of electric machines, this paper presents a literature survey on the state-of-the-art research trends of the electric machine related to FEA in the last 3 years. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Online measurement of pulverized fuel (PF) distribution between primary air pipes on a coal-fired power plant is of great importance to achieve balanced fuel supply to the boiler for increased combustion efficiency and reduced pollutant emissions. An instrumentation system using multiple electrostatic sensing heads is developed and installed on 510-mm bore primary air pipes on the same mill of a 600-MW coal-fired boiler unit for the measurement of PF mass flow and velocity distributions. An array of electrostatic electrodes with different axial widths is housed in a sensing head. An electrode with a greater axial width and three narrower electrodes are used to derive the electrostatic signals for the determination of PF mass flow rate and velocity, respectively. The PF velocity is determined by multiple cross correlation of the electrostatic signals from the narrow electrodes. The measured PF velocity is applied on the root-mean-square magnitude of the measured electrostatic signal from the wide electrode for the calibration of PF mass flow rate. On-plant comparison trials of the developed system were conducted under five typical operating conditions after a system calibration test. Isokinetic sampling equipment is used to obtain reference data to evaluate the performance of the developed system. Experimental data demonstrate that the developed system is effective and reliable for the online continuous measurement of the mass flow and velocity distributions between the primary air pipes of the same mill. [ABSTRACT FROM PUBLISHER]

The directed, head-to-tail self-assembly of microtubule filaments may be generalized in the context of Janus colloidal rods. Specifically, their assembly at the tens of micron-length scale involves a careful balance between long-range electrostatic repulsion and short-range attractive forces. Here we show that the addition of counterion salts increases the rate of directed assembly by screening the electrostatic forces and enhancing the effectiveness of short-range interactions at the microtubule ends. [ABSTRACT FROM AUTHOR]

Electrostatic precipitation is considered as an effective technology for fine particle removal. A lab-scale wet electrostatic precipitator (ESP) with wire-to-plate configuration was developed to study particle migration and collection. The performance of the wet ESP was evaluated in terms of the corona discharge characteristics, total removal efficiency and fractional removal efficiency. The corona discharge characteristics and particle removal abilities of the wet ESP were investigated and compared with dry ESP. Particle removal efficiency was influenced by discharge electrode type, SO2concentration, specific collection area (SCA) and particle/droplet interaction. Results showed that the particle removal efficiency of wet ESP was elevated to 97.86% from 93.75% of dry ESP. Three types of discharge electrodes were investigated. Higher particle removal efficiency and larger migration velocity could be obtained with fishbone electrode. Particle removal efficiency decreased by 2.87% when SO2concentration increased from 0 ppm to 43 ppm as a result of the suppression of corona discharge and particle charging. The removal efficiency increased with higher SCA, but it changed by only 0.71% with the SCA increasing from 25.0 m2/(m3/s) to 32.5 m2/(m3/s). Meanwhile, the increasing of particle and droplet concentration was favorable to the particle aggregation and improved particle removal efficiency. Implications: This work tends to study the particle migration and collection under spraying condition. The performance of a wet electrostatic precipitator (ESP) is evaluated in terms of the corona discharge characteristics, total particle removal efficiency, and fractional particle removal efficiency. The effects of water droplets on particle removal, especially on removal of particles with different sizes, is investigated. The optimization work was done to determine appropriate water consumption, discharge electrode type, and specific collection area, which can provide a basis for wet ESP design and application. [ABSTRACT FROM AUTHOR]

A new electrostatic ion storage ring, the RIKEN cryogenic electrostatic ring, has been commissioned with a 15-keV ion beam under cryogenic conditions. The ring was designed with a closed ion beam orbit of about 2.9 m, where the ion beam is guided entirely by electrostatic components. The vacuum chamber of the ring is cooled using a liquid-He-free cooling system to 4.2 K with a temperature difference of 0.4 K at most within all the positions measured by calibrated silicon diode sensors. The first cryogenic operation with a 15-keV Ne+ beam was successfully performed in August 2014. During the measurement, the Ne+ beam was stored under a ring temperature of 4.2 K with a residualgas lifetime of more than 10 min. This permits an estimation of the residual gas density at a few 104 cm-3, which corresponds to a room-temperature-equivalent pressure of around 1 × 10-10 Pa. An effect of longitudinal pulse compression at the bunching cavity in the ring was clearly identified by monitoring the pick-up beam detector. The detailed design and mechanical structure of the storage ring, as well as the results from the commissioning run, are reported. [ABSTRACT FROM AUTHOR]

Electrostatically formed nanowire (EFN)-based transistors have recently been proposed as a single device with multiplexer functionality. In these transistors, the conduction path between source and one of the drains is determined by the bias applied to the two junction-side gates. By applying a nonsymmetric bias on the side gates, the lateral position of the EFN is controlled. We present a detailed analysis of the different states of the multiple state electrostatically formed nanowire transistor device, the transient time between them and the power exerted during each transition. The dependence of transition time between states and leakage currents in cutoff states on different geometry parameters is also presented. [ABSTRACT FROM PUBLISHER]

A SOIMUMPs 1-D rotation micromirror is presented. The micromirror is driven by electrostatic vertical comb-drive actuators to work at resonant mode to scan a laser beam. The residual stress in the metal film coated on the SOI device layer is used to generate vertical offset in the comb-drive actuators with the combs located far from the rotation axis to increase the torque. A concave lens is designed to put after the micromirror to amplify the laser beam scanning angle, as well as to compensate for the curvature of the micromirror. A micromirror-based scanning system is used to build a laser line generator with a continuously adjustable fan angle, which solves the limitation of a fixed fan angle in conventional laser line generators. Prototypes of the micromirror and the laser line generator are fabricated and measured. A driving circuit that can generate a high-voltage square wave driving signal with adjustable amplitude and frequency is designed. All the parts are integrated in a 44 mm × 88 mm × 44 mm box and powered with a single 5-V power supply. The optical scanning angle under 100 V with or without the concave lens is 27 deg and 12 deg, respectively, at a resonant frequency of 900 Hz. [ABSTRACT FROM AUTHOR]

Spectral emissivity and constant heat capacities of molten nickel and rhodium at their melting temperatures were measured using containerless techniques. Samples were levitated in an electrostatic levitator and the radiation intensities from the molten samples were measured with spectrometers over a wide wavelength range. The spectrometers were calibrated with a blackbody radiation furnace and the spectral hemispherical emissivity was calculated. The total hemispherical emissivity of nickel at the melting temperature calculated by integrating the spectral hemispherical emissivity was found to be 0.21, and the constant pressure heat capacity of molten nickel at the melting temperature was calculated to be 39.9 J·mol −1 ·K −1 . The total hemispherical emissivity and the constant pressure heat capacity of rhodium at the melting temperature were measured to be 0.23 and 41.8 J·mol −1 ·K −1 , respectively. [ABSTRACT FROM AUTHOR]

Electrostatic sensor arrays (ESAs) are promising in industrial applications related to charged particle monitoring. Sensitivity is a fundamental and commonly-used sensing characteristic of an ESA. However, the usually used spatial sensitivity, which is called static sensitivity here, is not proper for moving particles or capable of reflecting array signal processing algorithms integrated in an ESA. Besides, reports on ESAs for intermittent particles are scarce yet, especially lacking suitable array signal processing algorithms. To solve the problems, the dynamic sensitivity of ESA is proposed, and a hemisphere-shaped electrostatic sensors’ circular array (HSESCA) along with its application in intermittent particle monitoring are taken as an example. In detail, a sensing model of the HSESCA is built. On this basis, its array signals are analyzed; the dynamic sensitivity is thereupon defined by analyzing the processing of the array signals. Besides, a component extraction-based array signal processing algorithm for intermittent particles is proposed, and the corresponding dynamic sensitivity is analyzed quantitatively. Moreover, simulated and experimental results are discussed, which validate the accuracy of the models and the effectiveness of the relevant approaches. The proposed dynamic sensitivity of ESA, as well as the array signal processing algorithm are expected to provide references in modeling, designing and using ESAs. [ABSTRACT FROM AUTHOR]

Despite all advances obtained with the pesticide use worldwide and in Brazilian agriculture, there is still a lack of technologies for agricultural aircrafts. The objective of this study was to evaluate the drift produced by the use of conical nozzles and electrostatic system in aircraft application. The experimental design was completely randomized with a factorial arrangement and four replications. Treatments included two spraying equipment: electrostatic system with 5L ha-1 of spray volume and conical nozzle with 15 and 20L ha-1. In all treatments, azoxystrobin fungicide was used at a dose of 100g a.i. ha-1 and paraffinic mineral oil at a dose of 0.5% v.v. Volume median diameter (VMD) and droplet density were estimated using water sensitive paper. Evaluations of drift distance were performed with glass collectors distributed horizontally on the soil surface, 50m before the application band, at the application site and 12,5, 25, 50, 75, 100, 150, 200 and 300m after the application site, along the wind direction. Azoxystrobin concentration in glasses were quantified by UHPLC-MS/MS. Results indicated that the drift distance can reach more than 300 meters away from the application site, with variable concentrations according to the equipment used. Electrostatic system reduced drift when compared to hydraulic conical nozzles. [ABSTRACT FROM AUTHOR]

We systematically studied Ge CMOS devices and logic circuits fabricated on a GeOI substrate, with the novel recessed channel and source/drain structures. Various channel lengths ( L\mathrm {ch} ) from 500 to 30 nm and channel thicknesses ( T\mathrm {ch} ) from 90 to 10 nm are implemented into the Ge CMOS devices and comprehensive geometry dependence analysis is carried out in terms of both L\mathrm {ch} and T\mathrm {ch} . With shrinking T\mathrm {ch} , the gate electrostatics are enhanced significantly but the on-state performance is found to be deteriorated simultaneously. It is also confirmed that Ge nMOSFETs are more sensitive to T\mathrm {ch} than pMOSFETs due to the phosphorus diffusion inside Ge. CMOS circuits, such as inverters, NANDs, NORs, and ring oscillators, are further investigated. [ABSTRACT FROM PUBLISHER]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel converter that can directly transform electrical, wind, hydraulic and other types of mechanical energy into thermal energy is presented in this study. First, the thermal energy of the converter is classified and then calculated by a finite element method. The eddy current distribution in the stator of the converter is also discussed. Second, the temperature field of the converter is calculated using a boundary element method. Subsequently, a thermal power-temperature coupled calculation method is presented to calculate the actual thermal power and temperature of the converter. The characteristic curves of the actual thermal power and the increase in water flow temperature are then presented based on the calculation results. Lastly, an experimental system is built, the thermal power and temperature of the converter are measured and the experimental results and the analytical calculations are compared. [ABSTRACT FROM AUTHOR]

To utilize polyvinylidene fluoride (PVDF) in novel integrated electrostatic devices, charge storage characteristics of PVDF thin film on wafer are analyzed and improved. Heat treatment method and layer thickness/stack are identified as two influencing factors. Among the four comparing heat treatment methods, the method of room temperature drying for 2 h followed by 90 °C baking for 3 h achieves PVDF films with better charge storage ability due to increased surface roughness and film compactness. Both initial surface potential and retain rate in 30 min increase as PVDF film thickness increases. Multiple layer stack exhibits better charge storage stability due to increased surface roughness and additional charge traps introduced by inter-layer interfaces. In this paper, optimal charge storage characteristics are obtained for three layer stack with 16 μm single layer thickness. Averagely, initial surface potential reaches −548.6 V and retain rate in 30 min reaches 91.0% @−600 V grid voltage & −6 kV needle voltage. [ABSTRACT FROM AUTHOR]

Copyright of Electrical Engineering & Electromechanics is the property of National Technical University, Kharkiv Polytechnic Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The analysis and design of electromechanical devices involve the solution of large sparse linear systems, and require therefore high performance algorithms. In this paper, the primal Domain Decomposition Method (DDM) with parallel forward-backward and with parallel Preconditioned Conjugate Gradient (PCG) solvers are introduced in two-dimensional parallel time-stepping finite element formulation to analyze rotating machine considering the electromagnetic field, external circuit and rotor movement. The proposed parallel direct and the iterative solver with two preconditioners are analyzed concerning its computational efficiency and number of iterations of the solver with different preconditioners. Simulation results of a rotating machine is also presented. [ABSTRACT FROM AUTHOR]

It is shown that conventional mathematical models for calculation of the reliability of electric machine structural units, based on the theory of planning an experiment, do not take into account the peculiarities of their properties variation during the process of manufacture and long-term operation. Taking into consideration the multiple factors of the assigned problem, the prospect of the use of fuzzy logic postulates in the creation of models for calculation of reliability is substantiated. An approach to such models building is formed. [ABSTRACT FROM AUTHOR]

ABSTRACT A very low-loss tunable evanescent-mode cavity bandpass filter (BPF) with one-octave (6-12 GHz) tuning range is presented. To implement a very low-insertion loss with wideband operation, a new coaxial-feed structure is devised in the tunable BPF. Across the entire tuning range, the achieved insertion loss is less than 0.5 dB. The 3-dB fractional bandwidth varies from 6.1% at 6 GHz to 12% at 12 GHz. The tenability is realized using silicon microelectromechanical systems diaphragms with slits that are electrostatically actuated. Direct comparison between a solid diaphragm and the proposed stress-reduced diaphragm with slits is presented. The bulk of the filter is realized using physical machining of a tall printed circuit board. This article shows the upper frequency limit that is feasible using milling. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2418-2422, 2015 [ABSTRACT FROM AUTHOR]

The spacecraft–plasma interaction simulator has been improved to allow for the simulation of lunar and asteroid dust emission, transport, deposition, and interaction with a spacecraft on or close to the lunar surface. The physics of dust charging and of the forces that they are subject to has been carefully implemented in the code. It is both a tool to address the risks faced by lunar probes on the surface and a tool to study the dust transport physics. We hereby present the details of the physics that has been implemented in the code as well as the interface improvements that allow for a user-friendly insertion of the lunar topology and of the lander in the simulation domain. A realistic case is presented that highlights the capabilities of the code as well as some general results about the interaction between a probe and a dusty environment. [ABSTRACT FROM PUBLISHER]

In order to simplify the sensors subsystems of the electrostatic torsional micromirrors (ETMs), the output feedback control for the ETM systems is investigated in this paper. The dynamics of the systems is established by combining the dynamics of both the mechanical and electronic subsystems, and it is proved that the dynamics of the overall system with uncertainties in electrical parameters can be exactly transformed into the third order linear system. Then an output feedback finite-time stabilizing (FTS) controller is presented by composing of a full state FTS observer and a state feedback FTS controller for the third order linear systems, such that the ETM systems can be stabilized in its full travel range by merely measuring the tilt angle. Some numerical simulations demonstrate the stability of the proposed output feedback FTS controller. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study of an electrostatic separation device for the recycling of granular plastic materials from waste electrical and electronic equipment (WEEE). The peculiarity of this system is the association of two charging techniques: 1) fluidized bed (dynamic charger) and 2) sliding on inclined plates (static charger)—and two superposed separation units, in order to achieve the selective sorting of a granular mixture composed of three different species of insulating materials. The tests were performed on a mixture of high-density polyethylene (HDPE), polyvinyl chloride (PVC), and polycarbonate (PC). A set of tribocharging experiments was conducted for each material, so that to choose the nature of the walls of the static charger. The analysis of the purity of separated products was performed using an image processing program written in MATLAB. High-purity separation (85%, 95%, and 75% for the PVC, PC, and HDPE products, respectively) was obtained at a recovery rate beyond 80%. [ABSTRACT FROM PUBLISHER]

Belt conveyors have been used for a long time in most of the industrial branches, as well as in places where the likelihood of explosive atmospheres occurrence exists. Therefore, the use of conveyor belts in hazardous environments requires fulfilling certain requirements, very important for the safety level to be provided, to prevent ignition sources. This paper highlights the main aspects related to assessment of explosion risk when using conveyor belts and certification of belt conformity with the applicable essential health and safety requirements performed by a third party body. [ABSTRACT FROM AUTHOR]

This article is aimed at evaluating three designs of cylindrical-type electrostatic precipitators that might be installed at the output of household boilers in order to reduce the pollution due to burning wood or fossil fuels. The first design is the “standard” precipitator, which consists in a thin copper wire (0.16 mm in diameter), coaxial with a cylindrical aluminum cylinder, 345 mm in length, of constant radius (20 mm). The second and third designs, equipped with a similar wire electrode, are characterized by the same global length, but are divided into three sections, two having the same cross-section as the “standard” precipitator, while the third section, 20 mm in length and located between them, has a smaller radius (11.5 mm). The reduction of the diameter in this central section of the precipitator is done by introducing an aluminum ring, covered by a sleeve made of either aluminum (design #2) or polyvinyl chloride (design #3). Together with the modification of the conditions for mechanical collection of particles, the more intense corona (design #2) or dielectric barrier discharges (design #3) generated in these sections of reduced diameter contribute to a significant increase of precipitation efficiency. [ABSTRACT FROM AUTHOR]

ABSTRACT Electrostatics is an inevitable phenomenon in fluidization processes and granular flow, where collisions between particulates and walls with different materials occur. In this work, a two-dimensional computational fluid dynamics model based on the Eulerian-Eulerian approach was applied and coupled with a first-principles electrostatic model to describe the gas-solid two-phase flow behavior in a fluid catalytic cracking (FCC) riser reactor under the electrostatic conditions. The coupled model was used to predict the main gas-solid flow distribution parameters in the FCC riser, such as electric potential, particle volume fraction, gas-phase temperature, and gas-phase component fractions. The simulation results showed that the electrostatic had a significant influence on the particle distribution in the bottom dense region of the FCC riser, whereas it had a weak influence in the upper dilute region at the cold-flow conditions. The simulation results also showed that the electrostatic had a weak influence on the particle concentration, gas-phase temperature, and lump concentration distributions when the cracking reaction was considered. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We report the design of a two-degree-of-freedom microelectromechanical systems nanopositioner for on-chip atomic force microscopy (AFM). The device is fabricated using a silicon-on-insulator-based process to function as the scanning stage of a miniaturized AFM. It is a highly resonant system with its lateral resonance frequency at ~850 Hz. The incorporated electrostatic actuators achieve a travel range of 16 μm in each direction. Lateral displacements of the scan table are measured using a pair of electrothermal position sensors. These sensors are used, together with a positive position feedback controller, in a feedback loop, to damp the highly resonant dynamics of the stage. The feedback controlled nanopositioner is used, successfully, to generate high-quality AFM images at scan rates as fast as 100 Hz. [ABSTRACT FROM AUTHOR]

Theoretical basics definition of force action in electric machines and revealing of the dynamics of their changes and harmonic composition are considered. The relevant calculated analysis of the forces which account for the conductors in the stator slots, of the forces acting on the tooth of the stator core and inside of the core as a whole, of the electromagnetic torque and a variable component is carried on the example of a turbogenerator in the load mode. The basis of the analysis are numeral-field calculation of the magnetic field in many positions and the use of Ampere's law and Maxwell's tensor magnetic tension. [ABSTRACT FROM AUTHOR]

The PM10 collection efficiency of a wire-cylinder electrostatic precipitator (ESP) was studied by means of a developed mathematical model, including the multi-field coupling between the gas flow field, the particle dynamic field and the electric field, and applying the Deutsch–Anderson Equation. The diffusion charging mechanism was considered due to the diameter range of PM10. The investigated variables were the applied potential, the gas velocity and the particle distribution. Numerical results indicate that the diffusion charging has significant influence on PM10 removal performance and the effect is more obvious with the decreasing diameter, and that the PM10 collection efficiency increases with the increasing applied potential and the increment of collection efficiency is more significant at lower voltage. Moreover, as the gas velocity at inlet decreases, collection efficiency of PM10 will increase. Finally, the overall efficiency increases with increasing the mean diameter of particle distribution. The research results can provide theoretical and technical references for the design of novel ESP aiming at economy and environment protection. [ABSTRACT FROM AUTHOR]

The dusty environment of the moon and the deposition of charged particles were troublesome in previous NASA explorations. In this study, an electrostatic lunar dust repeller (ELDR) was developed to mitigate the dust deposition problem. The ELDR consists of an arrangement of thin, needle-shaped electrodes in front of the protected surface to repel approaching, like-charged lunar dust. A discrete element method (DEM) was applied to track particle trajectories for determining the removal efficiency. Simulation results for single electrodes (L=5cm, D=1mm and L=10cm, D=1mm) both protecting a 5-cm×5-cm surface indicated that 4kV and 1.5kV were the respective-applied voltages required to achieve 100% protection from falling 20-µm lunar dust particles. The electrical particle–particle interaction was identified to be a beneficial factor. Finite element analysis concluded that an x-shaped pattern was the most effective arrangement of the ensemble electrodes to protect a 30-cm×30-cm surface. Modeling results showed that 2.2kV and 1.4kV were the minimum voltages applied to electrodes of length L=5 and 10cm, respectively, on each electrode of the ensemble model to achieve complete removal of 20-µm-sized particles. The ensemble-electrode ELDR required lower applied voltage than the single-electrode ELDR, and in the most conservative scenario, it consumed only 9 times more electric power to protect an area 36 times larger. [ABSTRACT FROM AUTHOR]

The article presents the results of diagnostic measurements of partial discharge signal propagation from the winding insulation in electrical machinery, which were performed using an on-line method. This paper describes the results of experiments and the acquired experience in the monitoring of winding insulation in high power and high voltage electrical machines which are important in industrial production processes. The authors show the measurement techniques employed in their research. Representative measurement results are presented along with their analysis. The authors use an SKF monitoring systems to measure: vibrations, temperature, and humidity, as major factors affecting partial discharge activity in the from winding insulation of electrical machines. [ABSTRACT FROM AUTHOR]