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This study aims to produce Fe2.9wt.%Si ferromagnetic material via laser powder bed fusion (L-PBF) for the realization of electromagnetic actuators (EMA). This study is necessary as there are no documents in scientific literature regarding the manufacturing of Iron-Silicon plungers using the L-PBF additive manufacturing (AM) technique. The microstructure, and magnetic properties were characterized using various techniques. The results indicate that the samples produced via L-PBF process exhibit good magnetic properties ( $\mu = 748, H_{C}= 87.7 [A/m]$ ) especially after annealing treatment at 1200° C for 1h ( $\mu = 3224, H_{C}= 69.1 [A/m] $ ), making it a promising material for use in electromagnetic actuators.

Brakes are essential parts of any system that involves motion. A few seconds are spent applying the brake, accumulating enough force to retard a system. In case of emergency stops, we need an efficient braking system that acts quickly and safely to avoid any mishaps. This work aims to develop a prototype of an instantaneous braking system, which can stop the motion of a rotating member. The operating principle of the device is the electromagnetic actuation of a solenoid. The actuation of a solenoid is simple and instantaneous. As a result, we could achieve immediate braking of a rotating member.

Brakes are essential parts of any system that involves motion. A few seconds are spent applying the brake, accumulating enough force to retard a system. In case of emergency stops, we need an efficient braking system that acts quickly and safely to avoid any mishaps. This work aims to develop a prototype of an instantaneous braking system, which can stop the motion of a rotating member. The operating principle of the device is the electromagnetic actuation of a solenoid. The actuation of a solenoid is simple and instantaneous. As a result, we could achieve immediate braking of a rotating member. [ABSTRACT FROM AUTHOR]

We describe a generally applicable method for the experimental determination of stationary flow conditions in pulsed supersonic beams, utilizing time-resolved electron induced fluorescence measurements of high pressure jet expansions of helium. The detection of ultraviolet photons from electronically excited helium emitted very close to the nozzle exit images the valve opening behavior-with the decided advantage that a photon signal is not affected by beam-skimmer and beam-residual gas interactions; it thus allows to conclusively determine those operation parameters of a pulsed valve that yield complete opening. The studies reveal that a 'flat-top' signal, indicating constant density and commonly considered as experimental criterion for continuous flow, is insufficient. Moreover, translational temperature and mean terminal flow velocity turn out to be significantly more sensitive in testing for the equivalent behavior of a continuous nozzle source. Based on the widely distributed Even-Lavie valve we demonstrate that, in principle, it is possible to achieve quasi-continuous flow conditions even with fast-acting valves; however, the two prerequisites are a minimum pulse duration that is much longer than standard practice and previous estimates, and a suitable tagging of the appropriate beam segment. [ABSTRACT FROM AUTHOR]

The article presents the discussion on investigation in a designed and modified standard automatic transmission for a 2017 Yamaha Grizzly All-Terrain Vehicle. Topics include developing a vehicle being used in the Australian outback for controlling and eradicating weeds; determining the performance parameters required for replacing the movement supplied by the operator; and improving productivity, profitability, and reducing the man time for performing tedious tasks such as spraying weeds.

This article presents a detailed approach to the analysis of a two-degree-of-freedom electromagnetic kinetic energy harvester. These systems use multiple disconnected masses that can impact each other and the harvester housing. This causes complex dynamics in the system as significant momentum is transferred between the masses and, ultimately, results in strongly nonlinear behaviour. One particular nonlinear phenomenon of interest, which has not been previously characterised, is anti-resonance. Observing this phenomenon is important as it highlights efficient energy transfer between the masses, and maximising its effect can be used to enhance the harvesters’ overall performance. A range of mathematical techniques are used to better explain the concept of anti-resonance and how it can be used to improve the understanding of the system dynamics. In addition, the widely used model for electromagnetic transduction is amended to give a more precise representation of the transducer force for this embodiment of the kinetic energy harvester. This unique analysis yields a rich modelling approach that can be used to inform future kinetic energy harvester designs by identifying and optimising key design parameters. Comparisons are made with experimental measurements of a two-mass electromagnetic kinetic energy harvester, validating the modelling approach. [ABSTRACT FROM AUTHOR]

Ferroelectrets are flexible and conformable polymer transducer foils with a dominant longitudinal piezoelectric effect. Ferroelectrets also have a negligible transverse piezoelectric effect, which makes them ideal for the fabrication of roll- and bendable keyboards. Cellular polypropylene ferroelectrets with heteropolar charge patterns are useful for a simple and effective key encoding. The preparation of charge patterns is, however, a technical challenge. We have investigated and produced such structures in cellular polypropylene ferroelectrets by corona poling, in combination with shadow masks and unstructured and structured counter electrodes. Furthermore, we have also produced lateral charge distributions by contact poling with specially designed high voltage electrodes. We discuss the two different poling concepts and the related problems, their strengths, weaknesses and experimental pitfalls. We found in particular contact poling to be a reliable and well reproducible poling method for an effective preparation of heteropolar charge patterns of ferroelectrets. [ABSTRACT FROM PUBLISHER]

This report provides practical guidelines for the use of inexpensive electromagnetic valves characterized by large dead volumes (tens to hundreds of μL) for the generation of small (nL) droplets on demand in microfluidic chips. We analyze the role of the ratio of resistances and of the elastic capacitance of the fluidic connectors between the reservoir of the liquid, the valve and the microfluidic chip in the reliable and precise formation of micro droplets on demand. We also demonstrate and examine the use of conventional electromagnetic squeeze valves in the generation of small droplets on demand with a similar set of design rules. [ABSTRACT FROM AUTHOR]

This paper shows the latest development and directions in Power Electronic simulations. One of them is visualization of the simulation results and "freeze and go back" feature is here introduced. As typical power electronics system analyses consist of many aspects and it is multidisciplinary an open interface and integrated approach is often applied. Requirements on the interface for an integrated simulator are given and communication between various tools and its structure is described in the paper and illustrated by many examples. [ABSTRACT FROM AUTHOR]

A compact sensor for physically sorting bioaerosols based on fluorescence spectra from single particles excited using arrays of ultraviolet light emitting diodes (UV LEDs) is presented. The optical system integrates electronics for real-time processing of spectral data and a miniaturized aerodynamic deflector for particle separation. Fluorescent polystyrene latex spheres are used to demonstrate fluorescence collection on-the-fly, operation of a real-time spectral algorithm, and physical separation of individual particles. This sensor illustrates the utility of recently developed UV LEDs, in conjunction with novel optical design and custom electronics, to shrink the size of aerosol fluorescence detection systems. [ABSTRACT FROM AUTHOR]

This paper looks at the collaborative design activity involved in a design experiment of an electromechanical plunger. Much of the coordination was achieved through internet-based communication. As mechanical and electrical researchers involved in the design project, we discuss the information exchanges highlighted by our different professional cultures and relate how these exchanges lead us to propose some methodology to improve the efficiency of virtual meetings. Moreover, we show the need for new communication tools, ones dedicated to specific tasks that are not currently supported, especially shared concept formalization among technical experts. [ABSTRACT FROM AUTHOR]

High-speed photography was used to study the collapse of a confined two-dimensional, air cavity in water, subjected to a propagating pressure disturbance. The 5–6 mm diameter cavity was confined in a rectangular duct. A sustained pressure disturbance was created by an accelerating piston in contact with the water 240 mm away from the bubble. The pressure increased from 0.1 MPa to about 0.12 MPa with a rise time of the order of 2 ms. The pressure pulse was not reflected until its arrival at the end of the duct, 320 mm from the piston. A microjet was produced at the proximal wall which penetrated the distal cavity wall, thereby producing a pair of bubbles which was thought to be regions of intense vorticity. The features of such confined bubble collapse were not found in previous investigations of unconfined bubble accelerations by weak pressure disturbances. Confinement apparently intensified the effect of the disturbance significantly. [ABSTRACT FROM AUTHOR]

This paper describes a scheme which allows two separate finite element meshes to slide into and thus overlap each other. The Lagrange Multipliers method is used to couple the two meshes together at their boundary. Overlapping elements are dealt with by adjusting the contributions of the elements of one of the two meshes to the system matrix according to the extent of overlap in such a way that at total overlap, those elements are effectively decoupled from the model. Applications include the modelling of electromagnetic plunger type devices. Index Terms - Electromagnetic fields, Finite element methods, Magnetostatics, Simulation.

Cellular polypropylene ferroelectrets are flexible transducer materials with dominant longitudinal piezoelectricity. They can be used for transient pressure sensing applications, due to the low cost of the sensor material. The authors show that ferroelectrets allow for the production of keyboards and touch pads with a customizable layout. Large area resistive electrodes on the ferroelectret with electronics at the edges avoid the preparation of complex sensor matrices. A touch pad of 10×10 cm2 area was tested by applying a force of 1.7 N on an area with a diameter of 5 mm in a grid matrix with 23×23 elements. [ABSTRACT FROM AUTHOR]

Isoporous membranes can be prepared by a combination of self-assembly of amphiphilic block copolymers and the non-solvent induced phase separation process. As the general doctor-blade technique suffers from high consumption of expensive block copolymer, other methods to reduce its concentration in the casting solution are sought after. Decreasing the block copolymer concentration during membrane casting and applying the block copolymer solution on a support membrane to obtain ultrathin isoporous membrane layers with e.g., spraying techniques, can be an answer. In this work we focused on the question if upscaling of thin block copolymer membranes produced by spraying techniques is feasible. To upscale the spray coating process, three different approaches were pursued, namely air-brush, 1-fluid nozzles and 2-fluid nozzles as generally used in the coating industry. The different spraying systems were implemented successfully in a membrane casting machine. Thinking about future development of isoporous block copolymer membranes in application it was significant that a continuous preparation process can be realised combining spraying of thin layers and immersion of the thin block copolymer layers in water to ensure phase-separation. The system was tested using a solution of polystyrene-block-poly(4-vinylpyridine) diblock copolymer. A detailed examination of the spray pattern and its homogeneity was carried out. The limitations of this method are discussed. [ABSTRACT FROM AUTHOR]

The balance is the most widely used complex measuring instrument in science and techniques. To install a balance on Mars is a challenge for numerous aspects of in situ measurements in the next decade. By means of a balance useful parameters could be determined and a variety of investigations could be carried out there. Possible applications of a balance on Mars are reviewed. Choice of type and demands on the balance with regard to the conditions on Mars are discussed. The first step is to test a load cell with strain gauge deflection sensor. [ABSTRACT FROM AUTHOR]

Focuses on technological advancement in electronic voice aids or artificial larynx (AL). Types of AL; Use of space age materials to improve type of machine; Changes on power sources of AL devices.