Mapping of force fields in a capacitively driven radiofrequency plasma discharge

In this paper a method is described that allows mapping of the forces acting on dust particles in a GEC reference cell. Monodisperse particles are dropped into the plasma environment and their trajectories are tracked using a high-speed camera system to determine local accelerations and respective forces. Collecting data from a large number of particle drops allows the identification of three-dimensional vector fields for the acting forces. The procedure is described and multiple examples in which the method has been applied are given. These examples include a simple plasma sheath, plasmas perturbed by a horizontal and vertical dipole magnet, an array of multiple magnets mimicking the fields found at a lunar swirl, and the fields inside a glass box used for particle confinement. Further applicability in other plasma environments will be discussed shortly.

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Blink-Spot Projection Method for Fast Three-Dimensional Shape Measurement

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2015.p0430 ◽

2015 ◽

Vol 27 (4) ◽

pp. 430-443 ◽

Cited By ~ 2

Author(s):

Jun Chen ◽

◽

Qingyi Gu ◽

Tadayoshi Aoyama ◽

Takeshi Takaki ◽

...

Keyword(s):

Projection Method ◽

Fast Moving ◽

High Speed ◽

Degrees Of Freedom ◽

Moving Objects ◽

Three Dimensional ◽

Frame Rate ◽

Light Illumination ◽

Camera System ◽

3D Shape

<div class=""abs_img""> <img src=""[disp_template_path]/JRM/abst-image/00270004/13.jpg"" width=""300"" /> Blink-spot projection method</div> We present a blink-spot projection method for observing moving three-dimensional (3D) scenes. The proposed method can reduce the synchronization errors of the sequential structured light illumination, which are caused by multiple light patterns projected with different timings when fast-moving objects are observed. In our method, a series of spot array patterns, whose spot sizes change at different timings corresponding to their identification (ID) number, is projected onto scenes to be measured by a high-speed projector. Based on simultaneous and robust frame-to-frame tracking of the projected spots using their ID numbers, the 3D shape of the measuring scene can be obtained without misalignments, even when there are fast movements in the camera view. We implemented our method with a high-frame-rate projector-camera system that can process 512 × 512 pixel images in real-time at 500 fps to track and recognize 16 × 16 spots in the images. Its effectiveness was demonstrated through several 3D shape measurements when the 3D module was mounted on a fast-moving six-degrees-of-freedom manipulator. </span>

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TOWARDS MACHINE VISION BASED RAILWAY ASSETS PREDICTIVE MAINTENANCE

Facta Universitatis Series Automatic Control and Robotics ◽

10.22190/fuacr2002125c ◽

2020 ◽

Vol 19 (2) ◽

pp. 125

Author(s):

Ivan Ćirić ◽

Milan Banić ◽

Miloš Simonović ◽

Aleksandar Miltenović ◽

Dušan Stamenković ◽

...

Keyword(s):

Machine Vision ◽

High Speed ◽

Rolling Contact Fatigue ◽

Three Dimensional ◽

Contact Fatigue ◽

Operational Reliability ◽

Rolling Contact ◽

Camera System ◽

Novel Technologies ◽

Three Dimensional Coordinate

The main goal of this paper is to present novel technologies that can contribute to safety, competitiveness, efficiency and operational reliability of Railway infrastructure through the development of innovative solutions for measuring and monitoring of railway assets based on machine vision. Measuring the transversal position of the wheels on the rail, as well as identification of the defects of the wheel and the rail (such as deformation of rail head edge, lateral wear, worn wheels, cracks in wheel and rail, rolling contact fatigue, corrugation and other irregularities) can increase reliability and lower maintenance costs. Currently, there is a need on the market for the innovative solution, namely the on-board high-speed stereo camera system augmented with a system that projects custom pattern (fringe scanner system) for measuring the transversal position of the wheels on the rail, robust to environmental conditions and waste along the track that can provide reliable measurements of transversal position of the wheels up to 200 km/h. New trends in Precise Industrial 3D Metrology are showing that stereo vision is an absolute must have in modern specialized optical precision measuring systems for the three-dimensional coordinate measurement.

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Three-Dimensional Fluid–Structure Interaction Case Study on Elastic Beam

Journal of Marine Science and Engineering ◽

10.3390/jmse8090714 ◽

2020 ◽

Vol 8 (9) ◽

pp. 714

Author(s):

Mahdi Tabatabaei Malazi ◽

Emir Taha Eren ◽

Jing Luo ◽

Shuo Mi ◽

Galip Temir

Keyword(s):

High Speed ◽

Flow Direction ◽

Fluid Structure Interaction ◽

Water Channel ◽

Three Dimensional ◽

Elastic Beam ◽

Flexible Beam ◽

Camera System ◽

Fluid Structure ◽

Structure Interaction

A three-dimensional T-shaped flexible beam deformation was investigated using model experiments and numerical simulations. In the experiment, a beam was placed in a recirculating water channel with a steady uniform flow in the inlet. A high-speed camera system (HSC) was utilized to record the T-shaped flexible beam deformation in the cross-flow direction. In addition, a two-way fluid-structure interaction (FSI) numerical method was employed to simulate the deformation of the T-shaped flexible beam. A system coupling was used for conjoining the fluid and solid domain. The dynamic mesh method was used for recreating the mesh. After the validation of the three-dimensional numerical T-shaped flexible solid beam with the HSC results, deformation and stress were calculated for different Reynolds numbers. This study exhibited that the deformation of the T-shaped flexible beam increases by nearly 90% when the velocity is changed from 0.25 to 0.35 m/s, whereas deformation of the T-shaped flexible beam decreases by nearly 63% when the velocity is varied from 0.25 to 0.15 m/s.

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High-speed imaging of dust particles in plasma

Journal of Plasma Physics ◽

10.1017/s0022377812000967 ◽

2012 ◽

Vol 79 (3) ◽

pp. 273-285 ◽

Cited By ~ 4

Author(s):

C. M. TICOŞ ◽

D. TOADER ◽

M. L. MUNTEANU ◽

N. BANU ◽

A. SCURTU

Keyword(s):

High Speed ◽

Imaging Techniques ◽

Dusty Plasmas ◽

Plasma Jets ◽

Plasma Sheath ◽

Dust Particles ◽

Digital Cameras ◽

Physical Processes ◽

High Speed Imaging ◽

Dust Plasma

AbstractHigh-speed imaging is a powerful tool for studying dusty plasmas. The recorded trajectories of dust particles can provide direct information about the physical processes involved in dust-plasma and dust–dust interactions. A review of some experiments and their imaging techniques employed for tracking dust particles immersed in low-ionized gases and in high-density plasma jets is presented. Digital cameras are used to record the motion of slow or hypervelocity dust particles dragged by plasma jets, or to evidence single or collective dust particle oscillations and vibrations in the plasma sheath.

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Numerical simulation of flow field in the pneumatic compact spinning systems using Finite Element Method

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-11-2017-0180 ◽

2018 ◽

Vol 30 (3) ◽

pp. 363-379 ◽

Cited By ~ 3

Author(s):

Xuzhong Su ◽

Xinjin Liu ◽

Xiaoyan Liu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Flow Field ◽

High Speed ◽

Three Dimensional ◽

Physical Models ◽

Camera System ◽

Content Type ◽

Compact Spinning ◽

Element Method

Purpose Pneumatic compact spinning is the most widely used compact spinning method at present, in which the negative pressure airflow is used to condense the fiber in order to decrease the spinning triangle and improve the yarn qualities. Therefore, the research on flow field in the condensing zone is always the emphasis for pneumatic compact spinning. The paper aims to discuss these issues. Design/methodology/approach By using finite element method (FEM), the flow field in two kinds of pneumatic compact spinning was studied. Taking three kinds of cotton yarns as examples, with the help of high-speed camera system OLYMPUS i-SPEED3, the motion trajectory of fiber strand in the condensing zone was obtained. Three-dimensional physical models of the condensing zone of the two compact spinning systems were obtained according to the measured parameters of practical spinning systems. Findings It is shown that on the both left edge of B1 line and right edge of B2 line, the airflow inflows to the center line of suction slot, and the condensed effects are produced, correspondingly. In the condensing zone, there are three condensing processes acting on the fiber strand, including the rapid condensing effects in the front condensing zone, the adequately condensing effects in the middle condensing zone, and stable output effects in the back condensing zone. Originality/value By using FEM, numerical simulations of three-dimensional flow field in condensing zone for two kinds of pneumatic compact spinning with lattice apron were presented, and corresponding spun yarn qualities were analyzed.

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Performance Investigation on Different Designs of Superhydrophobic Surface Texture for Composite Insulator

Materials ◽

10.3390/ma12071164 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1164 ◽

Cited By ~ 6

Author(s):

Meiyun Zhao ◽

Wei Li ◽

Yang Wu ◽

Xinze Zhao ◽

Mingyi Tan ◽

...

Keyword(s):

Superhydrophobic Surface ◽

High Speed ◽

Three Dimensional ◽

Optimal Parameters ◽

Textured Surfaces ◽

Composite Insulator ◽

Camera System ◽

Practical Applications ◽

Column Design

To investigate the superhydrophobic properties of different surface textures, nine designs of textures with micro-nanostructures were produced successfully using the laser engraving technique on the surfaces of composite insulator umbrella skirt samples made of silicon rubber. The optimal parameters of the texture designs to give rise to the best hydrophobicity were determined. The surface morphology, abrasion resistance, corrosion resistance, self-cleaning and antifouling property of the different textured surfaces as well as water droplets rolling on the textured surfaces were studied experimentally using a contact angle meter, scanning electron microscope, three-dimensional topography meter and high-speed camera system. It was found that the diamond column design with optimal parameters has the best superhydrophobicity and overall performance. The most remarkable advantage of the optimal diamond column design is its robustness and long-term superhydrophobicity after repeated de-icing in harsh conditions. The reported work is an important step towards achieving superhydrophobic surface without coating for outdoor composite insulator in practical applications.

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High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100168827 ◽

1994 ◽

Vol 52 ◽

pp. 218-219

Author(s):

Robert W. Mackin

Keyword(s):

Image Analysis ◽

High Speed ◽

Three Dimensional ◽

Image Data ◽

Ccd Camera ◽

Objective Lens ◽

Array Processor ◽

Vaginal Smears ◽

Low Contrast ◽

Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

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