A NEW ELECTROMAGNETIC FIELD TECHNIQUE

Geophysics ◽  
1955 ◽  
Vol 20 (2) ◽  
pp. 318-334 ◽  
Author(s):  
J. F. Enslin
Keyword(s):  
Electromagnetic Field ◽  
Alternating Current ◽  
Tangential Component ◽  
Minor Importance ◽  
Audio Frequency ◽  
Phase Measurements ◽  
Field Technique ◽  
Center Point ◽  
Concentric Circles ◽  
Absolute Measurements

A technique has been developed for accurate location of narrow vertical or inclined structures such as joints, fault planes, mineralized fissures, and weathered dykes. An alternating current of audio‐frequency is introduced conductively into the ground at a center‐point. Relative or absolute measurements of the tangential component of the resultant horizontal electromagnetic field are made at stations on concentric circles around the center‐point. Curves of the amplitudes, in decibels, are plotted as ordinates against the station positions. These are called the [Formula: see text]. The locations of peaks occurring vertically above current concentrations in narrow conducting zones are plotted on a map of the area and corresponding peaks are easily joined up to delineate such structures. Phase measurements have proved to be of minor importance for the location of geologic structures.

scholarly journals Electromagnetic field emitted by core–shell semiconductor nanowires driven by an alternating current

2021 ◽  
Vol 130 (3) ◽  
pp. 034301
Author(s):  
Miguel Urbaneja Torres ◽  
Kristjan Ottar Klausen ◽  
Anna Sitek ◽  
Sigurdur I. Erlingsson ◽  
Vidar Gudmundsson ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Alternating Current ◽  
Semiconductor Nanowires ◽  
Core Shell

Dynamic Chip Formation and its Significance to Machining Stability

1973 ◽  
Vol 187 (1) ◽  
pp. 273-283 ◽  
Author(s):  
D. F. Pearce ◽  
B. R. MacManus
Keyword(s):  
Cutting Force ◽  
Chip Formation ◽  
Chip Thickness ◽  
High Amplitude ◽  
Contact Length ◽  
Tangential Component ◽  
Shear Angle ◽  
Uncut Chip Thickness ◽  
Phase Measurements ◽  
Specific Contact

The physical processes of dynamic chip formation were examined experimentally using direct photographic techniques; motion in the cutting zone was frozen by synchronizing an intense stroboscopic flash to particular positions in the waveform of the cutting force. Measurements obtained under conditions of controlled vibratory machining gave instantaneous values of the uncut chip thickness, tool-chip contact length, effective shear angle and cutting force. At a given amplitude of uncut chip thickness the peak-to-peak variation of contact length was seen to attenuate with increasing frequency, an effect which was shown to be significant in causing relatively high amplitude shear angle oscillations. Amplitude and phase measurements of the tangential component of the cutting force on wave removal were directly related to the deduced waveform of specific contact length, a process yielding considerable predictability. Measurements were made of the damping inherent in the cutting process; results obtained by applying the techniques of impulse response testing showed the sensitivity of this damping to both the amplitude and the frequency of the variation of the uncut chip thickness. Internal damping resulting from the process of chip formation is not uniquely positive or negative but may vary, depending upon the combination of these parameters.

scholarly journals Online monitoring of polysaccharide solution concentration by electromagnetic field, electrical conductivity and spectrophotometry measurements

2021 ◽  
Author(s):  
Jussi Silvonen ◽  
Niko Järvelä ◽  
Markus Koppanen ◽  
Matti Järveläinen ◽  
Arto Ojuva ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Online Monitoring ◽  
Solution Concentration ◽  
Industrial Processes ◽  
Field Technique ◽  
Good Consistency ◽  
Resultant Solution ◽  
Concentration Changes ◽  
Electrical Permittivity

AbstractOnline control of industrial processes by lean principle increases productivity and yields higher product quality. Polysaccharides are dissolved in liquids, such as water, in many industrial products, like paints, cosmetics and culinary products. In these products, it is important to control viscosity or create thixotropy and yield stress for product functionality. Electromagnetic field and electrical conductivity techniques were applied to a meter polysaccharide dissolution process online up to a 0.5 wt% concentration, and the resultant solution was also further tested by UV–Vis spectrophotometry. The electromagnetic field technique measures changes in the local electrical permittivity of the liquid and the interest in this research were to find out whether the changes correlate to the concentration changes during the dissolution of polymer polysaccharide. The results that were obtained showed good consistency, suggesting the feasibility of the electromagnetic field technique in online monitoring of a polysaccharide suspension concentration. Moreover, this technique gives the advantage of instant monitoring of a polysaccharide dissolution for improved process control. Graphic abstract

A Fundamental Study on the Processing of Heavy Metals Contained in Underground Water by Composite Modulation Electromagnetic Field Processing

2014 ◽  
Vol 1025-1026 ◽  
pp. 661-667
Author(s):  
Sang An Ha ◽  
Dong Kyun Kim ◽  
Dong Won Lee ◽  
Byong Ho Jung ◽  
Jong Moon Lee ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Electromagnetic Field ◽  
Organic Contaminants ◽  
Water Contamination ◽  
Alternating Current ◽  
Underground Water ◽  
Redox Equilibrium ◽  
Fundamental Study ◽  
Continuous Type ◽  
Organic Complexes

The present study is aimed at deriving study factors appropriate for removal of heavy metals in a region with combined contamination of non-biodegradable organics or heavy metal ions in soil or underground water contamination or a region with underground water contamination using a composite alternating current electromagnetic field with combined modulation of an electric and a magnetic field. In addition, it is directed at deriving fundamental experiment, design factors that can be utilized in removing organic contaminants or metal-organic complexes having polarity of an electric charge. The continuous-type apparatus for fusion process in a composite alternating current electric field employed in the present study was designed to process a maximum of 260 L. Each configuration is provided with electrolytic decomposition apparatus, Magnetic Equipment, Power supply and Electrode plates with an adjustable distance between electrodes. By measuring oxidation and reduction processes of ions appearing in chemical reaction processes, electric potentials produced by injection of a negative reactivity electrode into an aqueous solution in a reversible redox equilibrium condition were measured.

Effect of Electromagnetic Field on Microstructure of 5052 Aluminum Alloy Sheet by Roll-Casting

2010 ◽  
Vol 146-147 ◽  
pp. 911-915
Author(s):  
Jin Tao Li ◽  
Guang Ming Xu ◽  
Jian Zhong Cui
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Static Magnetic Field ◽  
Alternating Current ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
Oscillation Effect ◽  
Electromagnetic Oscillation ◽  
Roll Casting

The effect of electromagnetic field on microstructure of roll-casting 5052 aluminum alloy sheet has been investigated and analyzed. The results indicate that imposing static magnetic field can refine the grains of 5052 aluminum alloy during the roll-casting; accordingly, imposing static magnetic field and alternating current at the same time, the grains are remarkably refined and equiaxed due to electromagnetic oscillation effect.

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