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

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1164 ◽  
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.

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

2015 ◽  
Vol 27 (4) ◽  
pp. 430-443 ◽  
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>

scholarly journals TOWARDS MACHINE VISION BASED RAILWAY ASSETS PREDICTIVE MAINTENANCE

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.

scholarly journals Time-resolved scanning ion conductance microscopy for three-dimensional tracking of nanoscale cell surface dynamics

2021 ◽  
Author(s):  
Samuel M. Leitao ◽  
Barney Drake ◽  
Katarina Pinjusic ◽  
Xavier Pierrat ◽  
Vytautas Navikas ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Cellular Structures ◽  
Surface Dynamics ◽  
Dynamic Changes ◽  
Ion Conductance ◽  
Time Resolved ◽  
Scanning Ion Conductance Microscopy ◽  
3D Information

Understanding cellular function requires high-resolution information about cellular structures as well as their evolution over time. The major challenge is to obtain three-dimensional (3D) information at nanometer resolution without affecting the viability of the cells and avoiding interference with the process. Here, we develop a scanning ion conductance microscope (SICM) for high-speed and long term imaging that can resolve spatiotemporally diverse processes on the cell membrane. We tracked dynamic changes in live cell morphology with nanometer details and temporal ranges of sub-second to days, imagining diverse processes ranging from endocytosis, micropinocytosis, and mitosis, to bacterial infection and cell differentiation in cancer cells. This technique enables a detailed look at membrane events and may offer insights into cell-cell interactions for infection, immunology, and cancer research.

scholarly journals Bibliography, catalogs, pixel data: Management of heterogeneous Big Data at CDS by the documentalists

2018 ◽  
Vol 186 ◽  
pp. 02001 ◽  
Author(s):  
M. Buga ◽  
P. Fernique ◽  
C. Bot ◽  
M. G. Allen ◽  
F. Bonnarel ◽  
...  
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Three Dimensional ◽  
Numerical Data ◽  
Large Data ◽  
Heterogeneous Data ◽  
Data Sets ◽  
Astronomical Data ◽  
Data Cubes

High speed Internet and the evolution of data storage space in terms of cost-effectiveness has changed the way data are managed today. Large amounts of heterogeneous data can now be visualized easily and rapidly using interactive applications such as “Google Maps”. In this respect, the Hierarchical Progressive Survey (HiPS) method has been developed by the Centre de Données astronomiques de Strasbourg (CDS) since 2009. HiPS uses the hierarchical sky tessellation called HEALPix to describe and organize images, data cubes or source catalogs. These HiPS can be accessed and visualized using applications such as Aladin. We show that structuring the data using HiPS enables easy and quick access to large and complex sets of astronomical data. As with bibliographic and catalog data, full documentation and comprehensive metadata are absolutely required for pertinent usage of these data. Hence the role of documentalists in the process of producing HiPS is essential. We present the interaction between documentalists and other specialists who are all part of the CDS team and support this process. More precisely, we describe the tools used by the documentalists to generate HiPS or to update the Virtual Observatory standardized descriptive information (the “metadata”). We also present the challenges faced by the documentalists processing such heterogeneous data on the scales of megabytes up to petabytes. On one hand, documentalists at CDS manage small size textual or numerical data for one or few astronomical objects. On the other hand, they process large data sets such as big catalogs containing heterogeneous data like spectra, images or data cubes, for millions of astronomical objects. Finally, by participating in the development of an interactive visualization of images or three-dimensional data cubes using the HiPS method, documentalists contribute to a long-term management of complex, large astronomical data.

scholarly journals Behavior of condensed droplets growth and jumping on superhydrophobic surface

2019 ◽  
Vol 128 ◽  
pp. 07003
Author(s):  
Sihang Gao ◽  
Fuqiang Chu ◽  
Xuan Zhang ◽  
Xiaomin Wu
Keyword(s):  
Growth Model ◽  
Superhydrophobic Surface ◽  
High Speed ◽  
Fluid Model ◽  
Chemical Deposition ◽  
Droplet Growth ◽  
Condensation Process ◽  
Camera System ◽  
Simulation And Experiment ◽  
Volume Of Fluid Model

Droplets on the superhydrophobic surface can fall off the surface spontaneously, which greatly promote dropwise condensation. This study considers a continuous droplet condensation process including droplet growth and droplet jumping. A droplet growth model considered NCG is developed and droplet jumping is simulated using VOF (Volume Of Fluid) model. Al–based superhydrophobic surfaces are prepared using chemical deposition and etching method. The Al-based superhydrophobic surface has a contact angle of 157°±1° and a rolling angle of 2°±1°. An observation experiment is designed to observe droplet jumping on superhydrophobic surface using a high– speed camera system. The result of droplet growth model shows a good match with experimental data in mid-term of droplet growth. Fordroplet jumping, simulation and experiment results show that droplet jumping of different diameter hasa universality in a non–dimensional form. The jumping process can be divided into 3 stages and droplet vibration is observed.

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

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.

Mapping of force fields in a capacitively driven radiofrequency plasma discharge

2016 ◽  
Vol 82 (4) ◽  
Author(s):  
Michael Dropmann ◽  
M. Chen ◽  
H. Sabo ◽  
R. Laufer ◽  
G. Herdrich ◽  
...  
Keyword(s):  
High Speed ◽  
Vector Fields ◽  
Three Dimensional ◽  
Plasma Discharge ◽  
Plasma Sheath ◽  
Dust Particles ◽  
Monodisperse Particles ◽  
Dipole Magnet ◽  
Camera System ◽  
Particle Confinement

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.

A Novel Peak-Seek Algorithm Used in FBG Sensor Demodulation System for Vibration Monitoring

2012 ◽  
Vol 160 ◽  
pp. 135-139 ◽  
Author(s):  
Lin Jun Cai ◽  
Zheng Ying Li ◽  
Zhi Hao Tang ◽  
Wei Meng ◽  
Quan Liu
Keyword(s):  
High Speed ◽  
Dynamic Range ◽  
Mechanical Vibration ◽  
Optical Power ◽  
Vibration Monitoring ◽  
Practical Applications ◽  
Fbg Sensor ◽  
Collection Data ◽  
The Stability

The FBG sensor technologies used for real-time monitoring of the mechanical vibration have attracted more and more concerns from both academic and industrial domains. In practical applications, the vibration frequency of the equipments generally reach up to a few hundred to several thousand Hz, however, the existing FBG demodulator is incompetent to meet the actual requirements of vibration monitoring in terms of demodulation speed and algorithm structures. To solve this problem while achieving a higher accuracy at a relatively lower computation cost, a novel adaptive semi-peak-seek algorithm based on state machine is proposed, which can be divided into three parts including data collection, data analysis and data verification. The experiment result shows that for the demodulation speed of 2 KHz, we can reach a demodulation accuracy of 1pm and a static noise within ±2pm. On the basis of a long term test, the stability error that less than 2pm and the system dynamic range of 0~ -30db are concluded, and the measurement error with the optical power attenuation is limited to 4pm. Thus, the proposed algorithm is capable to meet the requirements of high-speed demodulation devices in terms of speed, precision, stability and anti-interference properties.

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

2018 ◽  
Vol 30 (3) ◽  
pp. 363-379 ◽  
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.

Structures and Settlement Control of Yujingshan High-Speed Railway Tunnel Crossing Massive Rockfill in a Giant Karst Cave

2021 ◽  
pp. 036119812110624
Author(s):  
Yipeng Xie ◽  
Junsheng Yang ◽  
Cong Zhang ◽  
Jinyang Fu
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Three Dimensional ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Settlement Behavior ◽  
Underground River ◽  
Convergence Trend ◽  
Dimensional Coupling

The Yujingshan high-speed railway tunnel crosses a giant cavern system with a 108 × 104 m3 volume chamber and an 18 km long underground river. The massive project, which lasted three years, was eventually awarded the “Overcoming the Challenges” award by the International Tunneling and Underground Space Association (ITA) in 2020. However, since the cave chamber was filled with large-scale rockfill, structural settlement is a non-negligible problem. This paper presents the unique structures of a bridge supporting railway tracks wrapped by tunnel lining and the settlement control of the Yujingshan tunnel crossing massive rockfill in the giant cave. The geological characteristics and design considerations are systematically introduced. A three-dimensional coupling discrete element method (DEM) and finite difference method (FDM) numerical model and 13 months of long-term settlement monitoring were conducted to evaluate the settlement behavior. The results indicate that the morphology of cavern and internal deposits caused the whole rockfill to migrate to the lower left. The tunnel structure consequently developed a significant inclined settlement. The continuous construction load would increase the settlement value by 31.4%. The bottom reinforcement of steel-pipe pile with grouting could effectively inhibit settlement and differential settlement. Considering the simulation results, the tunnel bottom had greater settlement than the limit standard for high-speed railway embankment, which means this special structure form is reasonable for operation. Meanwhile, the monitoring results show that the tunnel bottom settlement in D3K279+891~D3K279+947 had not performed an apparent convergence trend after 13 months. Further structural monitoring and compensation grouting should be actively considered for operation maintenance.

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