UNCHARGED CONDUCTING TOROIDAL RING IN A UNIFORM ELECTRIC FIELD

1961 ◽  
Vol 39 (10) ◽  
pp. 1495-1500
Author(s):  
S. C. Loh
Keyword(s):  
Electric Field ◽  
Potential Function ◽  
Systematic Study ◽  
Theoretical Calculations ◽  
Numerical Results ◽  
Experimental Results ◽  
Uniform Electric Field ◽  
University Of Toronto ◽  
Mathematical Expressions ◽  
The University

Mathematical expressions for the potential function of an uncharged conducting toroidal ring placed in a uniform electric field are derived and expressed in terms of toroidal functions. Some numerical results were calculated by the IBM 650 computer at the University of Toronto and are included in the present paper. To verify the calculated results, a systematic study of an electrolytic tank was undertaken. It was found that the theoretical calculations agreed well with the experimental results.

The bursting of soap-bubbles in a uniform electric field

1925 ◽  
Vol 22 (5) ◽  
pp. 728-730 ◽  
Author(s):  
C. T. R. Wilson ◽  
G. I. Taylor
Keyword(s):  
Electric Field ◽  
Water Drop ◽  
The Other ◽  
Uniform Electric Field ◽  
Geometrical Shape ◽  
Soap Bubble ◽  
Charged Drop ◽  
Mathematical Discussion ◽  
Mathematical Expressions ◽  
The Stability

The stability of a charged raindrop has been discussed mathematically by Lord Rayleigh. The case of an uncharged drop in a uniform electric field is perhaps of more meteorological importance but a mathematical discussion of the conditions for stability turns out to be very much more difficult in this case, owing to the fact that the drop ceases to be spherical before it bursts. Moreover it does not seem possible to express its geometrical shape by means of any simple mathematical expressions. On the other hand, by using a soap bubble instead of a water drop it was found possible to carry out experiments under well-defined conditions in this case, whereas experiments with Rayleigh's charged drop would be difficult.

scholarly journals Charge Injection Characteristics of Semi-Conductive Composites with Carbon Black-Polymer for HVDC Cable

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1134 ◽  
Author(s):  
Yanhui Wei ◽  
Mingyue Liu ◽  
Wang Han ◽  
Guochang Li ◽  
Chuncheng Hao ◽  
...  
Keyword(s):  
Carbon Black ◽  
Electric Field ◽  
Bottom Electrode ◽  
Charge Injection ◽  
Experimental Results ◽  
Uniform Electric Field ◽  
Insulation Material ◽  
Electrode Structure ◽  
Depolarization Current ◽  
Conductive Composites

Semi-conductive composites composed of carbon black-polymer play an important role in uniform electric field in high voltage direct current (HVDC) cable. They also affect space charge behaviors in the insulation material. However, the charge injection characteristics of semi-conductive composites are not detailed. In this work, the electrode structure of ‘Semi-conductive composites- Insulation material- Metal bottom’ (S-I-M) is proposed, and the currents formed by injected charges from semi-conductive composites are characterized by the thermally stimulated depolarization current (TSDC) method. Further, the experimental results based on the structure of S-I-M are compared with the traditional electrode structure of M-I-M (Metal upper electrode- Insulation material- Metal bottom electrode) and the simplified cable electrode structure of MS-I-M (Metal upper electrode-Semi-conductive electrode- Insulation material- Metal bottom electrode), respectively. The experimental results show that the semi-conductive composite plays an important role in the charge injection process and it presents a different tendency under different compound modes of temperature and electric field. For the low electric field (E ≤ 5 kV/mm) and the low temperature (T ≤ 50 °C), the current caused by the accumulated charges follows the rule, IS > IMS > IM. For the low electric field and high temperature (T > 50 °C), the current caused by the injected charges follows the rule, IMS > IM > IS. This phenomenon is closely related to the interface characterization and contact barrier.

ELECTRIC FIELD-INDUCED INTERACTION FORCE BETWEEN TWO SPHERES

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1209-1214
Author(s):  
ZHIYONG WANG ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GANG SUN ◽  
KUNQUAN LU ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Field Strength ◽  
Electric Field ◽  
Theoretical Calculations ◽  
Interaction Force ◽  
Experimental Results ◽  
Field Frequency ◽  
Sphere Size

An apparatus is developed to study field-induced forces between two spheres. The mutual forces of a couple of identical spheres made of different materials in various media have been measured precisely as the function of inter-spherical spacing, field strength and field frequency. The respective dependences of the forces on inter-spherical spacing, field strength, field frequency and sphere size are obtained. By comparing the measured results with available theoretical calculations we conclude that a further improvement on the theoretical model should be carried out for explaining the most experimental results when the particle nearly contact.

scholarly journals Сверхвысокочастотный пробой воздуха, инициированный помещенным на диэлектрической поверхности электромагнитным вибратором

2019 ◽  
Vol 89 (7) ◽  
pp. 1016
Author(s):  
П.В. Булат ◽  
Л.П. Грачев ◽  
И.И. Есаков ◽  
А.А. Раваев ◽  
Л.Г. Северинов
Keyword(s):  
Electric Field ◽  
Wave Vector ◽  
Free Space ◽  
Theoretical Calculations ◽  
Electric Breakdown ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Dielectric Plate ◽  
Microwave Beam ◽  
Em Field

New results of experimental investigations of the possibility and conditions of initiation of electric breakdown of air in a quasi-optical microwave beam with a subcritical field level are described. The breakdown is initiated by a linear electromagnetic (EM) vibrator placed in a traveling EM wave on the surface of the dielectric sheet facing toward the wave vector k, on its opposite surface and near it. Simultaneously, theoretical calculations of the induced electric field near its ends were carried out for all variants of the vibrator location considered in the experiments. Numerical estimates and experimental results have shown that the placement of the vibrator on the surface of a dielectric plate can initiate a breakdown of air at significantly lower levels of the EM field in the microwave beam compared to the case of placing the vibrator in “free space”, i.e.at the absence of any dielectric plates

scholarly journals The Distribution of Electrons in a Uniform Electric Field

1995 ◽  
Vol 48 (1) ◽  
pp. 89
Author(s):  
IM Stewart
Keyword(s):  
Electric Field ◽  
New England ◽  
Current Source ◽  
Uniform Electric Field ◽  
Number Density ◽  
Transport Parameters ◽  
Cathodic Current ◽  
Secondary Current ◽  
Density Of Electrons ◽  
The University

Experiments are under way at the University of New England to measure the optical absorption of excited gas particles in a pre-breakdown discharge. Such measurements can be used to deduce the number density of electrons in the discharge. By comparing this experimental density map with the predictions of theory, electron transport parameters may be determined. In this paper, new theoretical expressions are derived for the number density distributions of electrons in a uniform electric field. These are found by solving the electron diffusion equation in a plane parallel electrode geometry with a radially symmetric cathodic current source. The contribution of ion-induced secondary current is included, and problems posed by non-equilibrium conditions near the electrodes are addressed. Techniques of data reduction are discussed with a particular emphasis on the avoidance of these problems.

Development of the University of Toronto Skull Base Inventory (UT-SBI) Quality-of-Life Questionnaire

Skull Base ◽  
2009 ◽  
Vol 19 (03) ◽  
Author(s):  
John de Almeida ◽  
Allan Vescan ◽  
Jolie Ringash ◽  
Patrick Gullane ◽  
Fred Gentili ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Skull Base ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
University Of Toronto ◽  
The University

Disruptive innovation and operationalization in local and sustainable food systems: Examining the University of Toronto-Local Food Plus partnership

2019 ◽  
Vol 6 (1) ◽  
pp. 120-139
Author(s):  
Lori Stahlbrand
Keyword(s):  
Food Systems ◽  
Large Scale ◽  
Food System ◽  
Local Food ◽  
Disruptive Innovation ◽  
Government Support ◽  
Sustainable Food ◽  
University Of Toronto ◽  
The University

This paper traces the partnership between the University of Toronto and the non-profit Local Food Plus (LFP) to bring local sustainable food to its St. George campus. At its launch, the partnership represented the largest purchase of local sustainable food at a Canadian university, as well as LFP’s first foray into supporting institutional procurement of local sustainable food. LFP was founded in 2005 with a vision to foster sustainable local food economies. To this end, LFP developed a certification system and a marketing program that matched certified farmers and processors to buyers. LFP emphasized large-scale purchases by public institutions. Using information from in-depth semi-structured key informant interviews, this paper argues that the LFP project was a disruptive innovation that posed a challenge to many dimensions of the established food system. The LFP case study reveals structural obstacles to operationalizing a local and sustainable food system. These include a lack of mid-sized infrastructure serving local farmers, the domination of a rebate system of purchasing controlled by an oligopolistic foodservice sector, and embedded government support of export agriculture. This case study is an example of praxis, as the author was the founder of LFP, as well as an academic researcher and analyst.

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