scholarly journals Direct current response of a thin scCVD diamond detector under increased applied field to 14.1 MeV neutrons

2021 ◽  
Author(s):  
Amber L. Guckes ◽  
Robert A. Buckles ◽  
Adam J. Wolverton ◽  
Irene V. Garza ◽  
Jesse A. Green ◽  
...  
Keyword(s):  
Direct Current ◽  
Applied Field ◽  
Current Response ◽  
Diamond Detector

scholarly journals Direct current response of a thin scCVD diamond detector under increased applied field to 14.1 MeV neutrons

2021 ◽  
Author(s):  
Amber Guckes ◽  
Robert Buckles ◽  
Adam Wolverton ◽  
Irene Garza ◽  
Jesse Green
Keyword(s):  
Direct Current ◽  
Applied Field ◽  
Current Response ◽  
Diamond Detector

Spatial characteristics of electric current and field in large direct-current coronas

1993 ◽  
Vol 441 (1911) ◽  
pp. 125-146 ◽  
Keyword(s):  
Space Charge ◽  
Direct Current ◽  
Current Density ◽  
Applied Field ◽  
Current Flow ◽  
Reasonable Accuracy ◽  
The Past ◽  
Field Distributions ◽  
Relationship Of ◽  
Very High

The distribution of corona currents arising at the plane of a rod/plane gap has been studied for the past 90 years by using small gaps ranging from 25 to 200 mm but it has not been known until recently whether this distribution changes markedly when the gap is increased to several metres, the sort of gap which is encountered in buildings where very high direct voltages are generated or distributed. The flow of corona creates a space-charge which, in turn, modifies the electric gradient across the gap; such gradients have not previously been measured in large gaps. The present paper reports the current density and field distributions over the plane of rod/plane gaps up to 3 m. The time taken for the space-charge to drift across the gap and the length of the trajectory have been deduced so that a general model of the current flow has been constructed with reasonable accuracy. The inter-relationship of the modification by space-charge of the original applied field and the current density has been established experimentally and theoretically. The phenomena have been studied for corona of both polarities.

scholarly journals The direct-current response of electrically conducting fractures excited by a grounded current source

Geophysics ◽  
2016 ◽  
Vol 81 (3) ◽  
pp. E201-E210 ◽  
Author(s):  
Chester J. Weiss ◽  
David F. Aldridge ◽  
Hunter A. Knox ◽  
Kimberly A. Schramm ◽  
Lewis C. Bartel
Keyword(s):  
Direct Current ◽  
Electric Potential ◽  
Effective Conductivity ◽  
Ground Deformation ◽  
Current Source ◽  
Deformation Monitoring ◽  
Local Perturbation ◽  
Current Response ◽  
Linear Inversion ◽  
Electrically Conducting

Hydraulic fracture stimulation of low permeability reservoir rocks is an established and cross–cutting technology for enhancing hydrocarbon production in sedimentary formations and increasing heat exchange in crystalline geothermal systems. Whereas the primary measure of success is the ability to keep the newly generated fractures sufficiently open, long–term reservoir management requires a knowledge of the spatial extent, morphology, and distribution of the fractures — knowledge primarily informed by microseismic and ground deformation monitoring. To minimize the uncertainty associated with interpreting such data, we investigate through numerical simulation the usefulness of direct-current (DC) resistivity data for characterizing subsurface fractures with elevated electrical conductivity by considering a geophysical experiment consisting of a grounded current source deployed in a steel cased borehole. In doing so, the casing efficiently energizes the fractures with steady current. Finite element simulations of this experiment for a horizontal well intersecting a small set of vertical fractures indicate that the fractures manifest electrically in (at least) two ways: (1) a local perturbation in electric potential proximal to the fracture set, with limited farfield expression and (2) an overall reduction in the electric potential along the borehole casing due to enhanced current flow through the fractures into the surrounding formation. The change in casing potential results in a measurable effect that can be observed far from fractures themselves. Under these conditions, our results suggest that farfield, timelapse measurements of DC potentials can be interpreted by simple, linear inversion for a Coulomb charge distribution along the borehole path, including a local charge perturbation due to the fractures. This approach offers an inexpensive method for detecting and monitoring the time-evolution of electrically conducting fractures while ultimately providing an estimate of their effective conductivity — the latter providing an important measure independent of seismic methods on fracture shape, size, and hydraulic connectivity.

Polymer Cut-Off Wall Quality Testing Based on Direct Current Response Measuring

2013 ◽  
Vol 838-841 ◽  
pp. 1715-1718
Author(s):  
Xuan Lou ◽  
Rui Wang ◽  
Yang Zhou
Keyword(s):  
Elastic Wave ◽  
Direct Current ◽  
Current Response ◽  
Testing Methods ◽  
Resistivity Imaging ◽  
Testing Method ◽  
Dc Potential ◽  
Quality Testing ◽  
Wave Tomography ◽  
Full Scale Tests

Polymer Cut-off wall is a new kind of anti-seepage work used in hydraulic and civil engineering. It is quite different from concrete cut-off wall in materials and sizes. Traditional quality testing methods such as elastic wave tomography, GPR and resistivity imaging are all not applicable in polymer cut-off wall quality testing. We design a new testing method based on DC potential measuring. We use electrodes to build underground electric field and measuring the change of potential near the wall to analysis the integrity of the wall. We finish a series of indoor model and some full-scale tests. The results prove that the method is effective and practicable in polymer cut-off wall quality testing.

scholarly journals Renewable Energy Source Enactment for Speed Control of BLDC Motor with Proportional Integral (PI) Controller

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Soedibyo Soedibyo
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Renewable Energy ◽  
Direct Current ◽  
Speed Control ◽  
Pi Controller ◽  
Current Response ◽  
Bldc Motor ◽  
Proportional Integral ◽  
Pv Array

This paper present about speed control of Brushless Direct Current (BLDC) Motor 1 kW in which supplied using Photovoltaic (PV) Array 1.5 kW that simulated using MATLAB 2016a.  Speed control of BLDC exactly depend on voltage condition, so speed control mean voltage control. Furthermore, Proportional Integral (PI) controller will be implemented to get best performance of the system during irradiance change or some load implemented. For detail analysis purpose, the simulation will do in some case such by vary irradiation of PV, Vary the speed reference then vary of load. From simulation result we get the information that dynamic irradiance, load and speed reference will influence the response stability of speed so do Power Consumption, Voltage and Current response.

On the optimum applied field for magnetic particle inspection using direct current

1982 ◽  
Vol 3 (3) ◽  
pp. 125-136 ◽  
Author(s):  
C. L. Oehl ◽  
L. J. Swartzendruber
Keyword(s):  
Direct Current ◽  
Applied Field ◽  
Magnetic Particle ◽  
Magnetic Particle Inspection

Alternating current response and visualization of electrorheological fluid

2019 ◽  
Vol 31 (2) ◽  
pp. 288-296
Author(s):  
Tobias Bauerochs ◽  
Xiaoye Huo ◽  
Gilad Yossifon ◽  
Stephan Ulrich ◽  
Steffen Schneider ◽  
...  
Keyword(s):  
Direct Current ◽  
Electrorheological Fluid ◽  
Alternating Current ◽  
Superior Performance ◽  
Low Flow ◽  
Current Response ◽  
Pressure Drops ◽  
Electrorheological Effect ◽  
Current Voltage ◽  
Fluidic Device

The electrorheological effect produced by an ER-Fluid with an applied electric field is not yet fully understood. However, it is significant to understand how the viscosity increases, and thus, the ER-Effect works to optimally design ER-Applications. In this article, the ER-Effect and its response to different voltage forms with varying frequencies within a miniature fluidic device are described and visualized using a microscope. The different pressure drops across the channel are measured. Problems such as long saturation times using microchannels in combination with low flow velocities are described and explained. An electric frequency dependence of the chain formation has been discovered and that the use of alternating current offers superior performance in comparison with direct current. The optimal operating point for achieving the largest possible pressure difference is from 5 to 10 Hz for square wave voltages. In this frequency range, the performance of the electrorheological effect is greater than using direct current. From approximately 10 Hz, the power decreases with increasing electric frequency. Above 20 Hz, direct current is superior to alternating current voltage, so is not recommended for use in this range.

Inter-Method Reliability of Pulse Volume Related Measures Derived Using Finger-Photoplethysmography

2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi
Keyword(s):  
Light Intensity ◽  
Adverse Effects ◽  
Light Source ◽  
Direct Current ◽  
Resting State ◽  
Current Component ◽  
Psychophysiological Measures ◽  
Pulse Volume ◽  
Optical Paths ◽  
Sensor Positions

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.

Direct current

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2015 ◽  
Keyword(s):  
Direct Current
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