Use of Dielectric Spectroscopy for the Study of Concentration of Glyphosate in Distilled Water

In this paper, the capability of sensing low concentrations of glyphosate in water of two interdigital capacitive transducers are analyzed using numerical simulations and measurements. Each microwave sensor is analyzed using the surface electric field produced at the resonance frequency. In addition, the reflection coefficient of each transducer submerged in water with glyphosate is measured and compared with distilled water. Prepared samples with concentrations of 1ppm/L (1 part per million over a liter of distilled water) are used for the experimental tests.

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The Effect of Roughness Features on Mos Surface Electric Field and Fowler-Nordheim Tunneling Behavior

MRS Proceedings ◽

10.1557/proc-473-175 ◽

1997 ◽

Vol 473 ◽

Author(s):

Heng-Chih Lin ◽

Edwin C. Kan ◽

Toshiaki Yamanaka ◽

Simon J. Fang ◽

Kwame N. Eason ◽

...

Keyword(s):

Electric Field ◽

Three Dimensional ◽

Tunneling Current ◽

Gate Oxide ◽

Oxide Thickness ◽

Interface Roughness ◽

Normal Electric Field ◽

Surface Electric Field ◽

Tunneling Behavior ◽

Nordheim Tunneling

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.

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On the effect of pilot holes on the mechanical behaviour of flow-drill screw joints. Experimental tests and mesoscale numerical simulations

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2021.117133 ◽

2021 ◽

Vol 294 ◽

pp. 117133

Author(s):

Miguel Costas ◽

David Morin ◽

Johan Kolstø Sønstabø ◽

Magnus Langseth

Keyword(s):

Numerical Simulations ◽

Mechanical Behaviour ◽

Experimental Tests

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AC Current Ripple in Three-Phase Four-Leg PWM Converters with Neutral Line Inductor

Energies ◽

10.3390/en14051430 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1430

Author(s):

Aleksandr Viatkin ◽

Riccardo Mandrioli ◽

Manel Hammami ◽

Mattia Ricco ◽

Gabriele Grandi

Keyword(s):

Numerical Simulations ◽

Pulse Width Modulation ◽

Neutral Line ◽

Experimental Tests ◽

Performance Comparison ◽

Design Parameters ◽

Switching Frequency ◽

Three Phase ◽

Ac Current ◽

Current Ripple

This paper presents a comprehensive study of peak-to-peak and root-mean-square (RMS) values of AC current ripples with balanced and unbalanced fundamental currents in a generic case of three-phase four-leg converters with uncoupled AC interface inductors present in all three phases and in neutral. The AC current ripple characteristics were determined for both phase and neutral currents, considering the sinusoidal pulse-width modulation (SPWM) method. The derived expressions are simple, effective, and ready for accurate AC current ripple calculations in three- or four-leg converters. This is particularly handy in the converter design process, since there is no need for heavy numerical simulations to determine an optimal set of design parameters, such as switching frequency and line inductances, based on the grid code or load restrictions in terms of AC current ripple. Particular attention has been paid to the performance comparison between the conventional three-phase three-leg converter and its four-leg counterpart, with distinct line inductance values in the neutral wire. In addition to that, a design example was performed to demonstrate the power of the derived equations. Numerical simulations and extensive experimental tests were thoroughly verified the analytical developments.

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