Physical model for near-field scattering and manipulation

2004 ◽  
Author(s):  
Djenan Ganic ◽  
Xiaosong Gan ◽  
Min Gu
Keyword(s):  
Physical Model ◽  
Near Field

Coherent structures of the near field flow in a self-oscillating physical model of the vocal folds

2007 ◽  
Vol 121 (2) ◽  
pp. 1102-1118 ◽  
Author(s):  
Jürgen Neubauer ◽  
Zhaoyan Zhang ◽  
Reza Miraghaie ◽  
David A. Berry
Keyword(s):  
Physical Model ◽  
Coherent Structures ◽  
Near Field ◽  
Vocal Folds

Near-field mixing at an outfall

1996 ◽  
Vol 23 (1) ◽  
pp. 63-75 ◽  
Author(s):  
S. T. Abdel Gawad ◽  
J. A. McCorquodale ◽  
H. Gerges
Keyword(s):  
Great Lakes ◽  
Key Words ◽  
Physical Model ◽  
Correction Factor ◽  
Concentration Distribution ◽  
Field Data ◽  
Near Field ◽  
Mass Conservation ◽  
Buoyant Flow ◽  
Buoyant Flows

The near-field mixing of effluent from buoyant and nonbuoyant flows from outfalls discharging into a cross-flowing ambient current in trapezoidal channels has been investigated. A physical model was scaled to represent a typical large outfall into one of the connecting channels of the Great Lakes system. The discharged jet was measured in detail to determine the velocity and concentration fields. The excess velocities and concentrations were found to follow the Gaussian distribution. Empirical expressions for the jet trajectories, minimum dilutions, and plume widths were derived. A correction factor has been introduced to the concentration distribution to ensure mass conservation. The calibrated model was verified by comparison with field data and the results of other near-field models (PDS, MIT, and CORMIX). Key words: mixing, near field, pollutant transport, outfall, buoyant flow, non-buoyant flows.

The physical model and validation study of ceiling-jet flow in near-field of corridor fires

2015 ◽  
Vol 88 ◽  
pp. 91-100 ◽  
Author(s):  
Weifeng Zhao ◽  
Ruowen Zong ◽  
Tao Wei ◽  
Xuejuan Zhao ◽  
Guangxuan Liao
Keyword(s):  
Physical Model ◽  
Validation Study ◽  
Near Field ◽  
Jet Flow

scholarly journals A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons

2016 ◽  
Vol 472 (2191) ◽  
pp. 20160338 ◽  
Author(s):  
Ray T. Smith ◽  
Fred P. M. Jjunju ◽  
Iain S. Young ◽  
Stephen Taylor ◽  
Simon Maher
Keyword(s):  
Physical Model ◽  
Electromagnetic Induction ◽  
Near Field ◽  
Low Frequency ◽  
Direct Interaction ◽  
Induced Voltage ◽  
Principle Of Superposition ◽  
Sensor Applications ◽  
Direct Explanation ◽  
Uniform Current

A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting’s theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

Principles of Planar Near-Field Antenna Measurements

2007 ◽  
Author(s):  
Stuart Gregson ◽  
John McCormick ◽  
Clive Parini
Keyword(s):  
Near Field ◽  
Antenna Measurements

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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