A novel technique of electrical strengthening of soft sensitive clays by dielectrophoresis

1992 ◽  
Vol 29 (4) ◽  
pp. 599-608 ◽  
Author(s):  
K. Y. Lo ◽  
K. S. Ho ◽  
I. I. Inculet
Keyword(s):  
Shear Strength ◽  
Electric Field ◽  
High Voltage ◽  
Alternating Current ◽  
Novel Technique ◽  
Strain Behaviour ◽  
Preconsolidation Pressure ◽  
Electro Osmosis ◽  
Sensitive Clay ◽  
Applied Electric Potential

A novel technique of electrical strengthening of soil by dielectrophoresis was developed. The process employs an alternating current at high voltage, generating a converging electric field towards the electrode by which a net resultant movement of water in the clay mass is produced towards the direction of stronger electric field intensity. Laboratory tests were developed to investigate the mechanism of this process and to explore the possibility of its application in electrical strengthening of soft sensitive clays. The preliminary results of this study showed that the process is effective, and the shear strength of the treated clay (Wallaceburg clay) increased drastically by several times with a reduction of moisture content of approximately 25% at an applied electric potential of 20 kV for 28 days. When compared with electro-osmosis, similar results are obtained in dielectrophoresis, such as the increase in preconsolidation pressure, decrease in sensitivity, and improvement of stress–strain behaviour. It is also shown that the improvement of soil properties can be greatly enhanced by increasing the applied voltage and electrode depth. Key words : dielectrophoresis, alternating current, converging electric field, high-voltage electrode, dielectric constant, electro-osmosis, soft sensitive clay, shear strength, consolidation.

Electrical strengthening of clays by dielectrophoresis

1994 ◽  
Vol 31 (2) ◽  
pp. 192-203 ◽  
Author(s):  
K.Y. Lo ◽  
J.Q. Shang ◽  
I.I. Inculet
Keyword(s):  
Shear Strength ◽  
Electric Field ◽  
Soil Improvement ◽  
Nonuniform Electric Field ◽  
Experimental Program ◽  
Effective Polarizability ◽  
Clay Particles ◽  
Shearing Resistance ◽  
Preconsolidation Pressure ◽  
Sensitive Clay

The theory of dielectrophoresis in clay–water–electrolyte systems is developed in this paper. Dielectrophoresis is the motion of particles generated by a nonuniform electric field. The dielectrophoretic forces on clay particles are determined by the effective polarizability and configuration of the nonuniform electric field. In most clay–water–electrolyte systems, including natural clays, the dielectrophoretic forces are directed towards the lower field intensity, determined by the negative polarizability. In the experimental program, an ac voltage of 60 Hz and 15 kV was applied through insulated electrodes on block samples of Leda clay for 28 days. The relationship between the soil undrained shear strength after treatment and the distribution of electric field provides direct experimental support for the theory developed. Under three electrical-field configurations, the overall shear strengths increased up to 44.0%, concurrent with significant reduction of sensitivity. The improvement of soil properties was also reflected as increases of preconsolidation pressure and shearing resistance in terms of effective stresses. The electrochemical reactions associated with electric current were minimized by insulation to the electrodes. Key words : dielectrophoresis, electrokinetics, soil improvement, sensitive clay, shear strength.

scholarly journals Methodology to calculate the intensity of the electric field generated in a double circuit High Voltage Alternating Current overhead transmission line

2020 ◽  
pp. 1-8
Author(s):  
Jorge Luis Aguilar-Marin ◽  
Julio Cesar Vergara-Vázquez ◽  
Jorge Gabriel Padilla-Cantero ◽  
Daniel Hernández-González
Keyword(s):  
Electric Field ◽  
Transmission Line ◽  
High Voltage ◽  
Transmission Lines ◽  
Simulation Method ◽  
Alternating Current ◽  
Image Method ◽  
Overhead Transmission Line ◽  
The Right ◽  
Load Simulation

One of the parameters considered in the design of transmission lines is the distribution of its generated electric field. The following article presents a reference methodology that allows obtaining the electric field on the right-of-way of a High Voltage Alternating Current (HVAC) overhead transmission line, the methodology is developed based on the Load Simulation Method (MSC) and the Image Method. The results obtained present a difference of less than 2%. In this way a case study of a 230 kV HVAC double circuit transmission line presented, an optimization of the phases of the transmission line circuits is carried out to determine the most efficient configuration for obtaining the electric field density. The results obtained allow a configuration of n circuits, admitting the different nominal voltages of the HVAC lines.

scholarly journals Effect of fouling resistance in heat exchanger and the crystal form of CaCO3 in hard circulating cooling water with electrostatic field and alternating current electric field

2021 ◽  
Author(s):  
Jing Xu ◽  
Ju-Dong Zhao ◽  
Yun Jia ◽  
Ting Li ◽  
Shuai-Bing Yang ◽  
...  
Keyword(s):  
Water Quality ◽  
Heat Exchanger ◽  
Electric Field ◽  
High Voltage ◽  
Alternating Current ◽  
Inhibition Effect ◽  
Scale Inhibition ◽  
Current Electric Field ◽  
Electric Field Treatment ◽  
Heat Exchanger Surface

Abstract The effect of high voltage electrostatic field and high voltage alternating current electric field on the heat exchanger surface fouling under the condition of hard water was investigated. The Ca2+ concentration in two water conditions was 12 mmol/L. The Mg2+ concentration was 10 mmol/L and 12 mmol/L respectively. The concentration changed with the Mg2+ concentration. X-ray diffraction and Scanning electron microscope results confirmed that the main crystal phases of the scale samples consist of calcite and aragonite. The high voltage electrostatic treatment can promote scale growth under both water quality conditions. However, the high voltage alternating current electric field treatment shows a good scale inhibition effect under both water quality conditions, and the scale inhibition effect is best when both Ca2+ and Mg2+ concentrations are 12 mmol/L, and the average scale inhibition rate reaches 47.58%. When the calcite content of the scale sample is significantly higher than that of aragonite, Mg2+ affects the growth and solubility of crystals. On the other hand, the high voltage alternating current electric field treatment can effectively extend the fouling induction period of the adherent scale on the heat exchanger surface, which is favorable for heat exchanger fouling.

Anisotropic behaviour of a sensitive clay

1979 ◽  
Vol 16 (2) ◽  
pp. 335-350 ◽  
Author(s):  
R. N. Yong ◽  
V. Silvestri
Keyword(s):  
Mechanical Response ◽  
Plastic Material ◽  
Anisotropic Elasticity ◽  
True Triaxial ◽  
Anisotropic Behaviour ◽  
Strain Behaviour ◽  
Preconsolidation Pressure ◽  
Confining Pressures ◽  
Sensitive Clay ◽  
Elastic Plastic Material

This paper presents the results of a study carried out to determine the drained stress–strain behaviour of a sensitive clay from St-Louis de Bonsecours (Quebec), tested under conventional axisymmetric (σ′1 > σ′2 = σ′3) and complex true-triaxial (σ′1 ≠ σ′2 ≠ σ′3) stress states.The data reported herein show that, for confining pressures below the preconsolidation pressure of the clay, the influence of cementation bonds and anisotropy results in deviation from the Mohr–Coulomb theory and causes the clay to behave as an anisotropic pseudo-elastic, plastic material. It is shown that constitutive relationships derived from the theories of anisotropic elasticity and plasticity represent very well the mechanical response of the clay.

PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

Jurnal Teknik ◽  
2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Mauludi Manfaluthy
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
High Voltage ◽  
Low Frequency ◽  
Energy Utilization ◽  
World Health ◽  
Electromagnetic Signals ◽  
Health Organization ◽  
The Magnetic Field ◽  
Low Frequency Waves

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under  100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms. The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.Keywords : Radiance Energy, Joule Thief, and  LED Module.

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