Investigation of the stability of graphene devices  for quantum resistance metrology at direct and  alternating current

2022 ◽  
Author(s):  
Dong-Hun Chae ◽  
Mattias Kruskopf ◽  
Jan Kučera ◽  
Jaesung Park ◽  
Yefei Yin ◽  
...  
Keyword(s):  
Direct Current ◽  
Electronic Transport ◽  
Carrier Density ◽  
Alternating Current ◽  
Hall Resistance ◽  
Interlaboratory Comparisons ◽  
Good Reproducibility ◽  
Doped Graphene ◽  
Graphene Devices ◽  
The Stability

Abstract Interlaboratory comparisons of the quantized Hall resistance are essential to verify the international coherence of primary impedance standards. Here we report on the investigation of the stability of p-doped graphene-based quantized Hall resistance devices at direct and alternating currents at CMI, KRISS, and PTB. To improve the stability of the electronic transport properties of the polymer encapsulated device, it was shipped in an over-pressurized transport chamber. The agreement of the quantized resistance with RK/2 at direct current was on the order of 1 nΩ/Ω between 3.5 T and 7.5 T at a temperature of 4.2 K despite changes in the carrier density during the shipping of the devices. At alternating current, the quantized resistance was realized in a double-shielded graphene Hall device. Preliminary measurements with digital impedance bridges demonstrate the good reproducibility of the quantized resistance near the frequency of 1 kHz within 0.1 μΩ/Ω throughout the international delivery.

Electronic transport and localization in nitrogen-doped graphene devices using hyperthermal ion implantation

2016 ◽  
Vol 93 (16) ◽  
Author(s):  
Adam L. Friedman ◽  
Cory D. Cress ◽  
Scott W. Schmucker ◽  
Jeremy T. Robinson ◽  
Olaf M. J. van ‘t Erve
Keyword(s):  
Ion Implantation ◽  
Electronic Transport ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Graphene Devices

Comparison of alternating current with direct current electroshock across the closed chest

1962 ◽  
Vol 10 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Bernard Lown ◽  
Jose Neuman ◽  
Raghavan Amarasingham ◽  
Barouh V. Berkovits
Keyword(s):  
Direct Current ◽  
Alternating Current ◽  
Closed Chest

CONCEPTS OF ELECTRONICALLY-CONTROLLED ELECTROMECHANICAL/MECHANOELECTRICAL STEER-, AUTODRIVE- AND AUTOABSORBABLE WHEELS FOR ENVIRONMENTALLY-FRIENDLY TRI-MODE SUPERCARS

1994 ◽  
Vol 04 (04) ◽  
pp. 501-516 ◽  
Author(s):  
BOGDAN T. FIJALKOWSKI ◽  
JAN W. KROSNICKI
Keyword(s):  
Direct Current ◽  
Integrated Circuit ◽  
Environmentally Friendly ◽  
Alternating Current ◽  
Switching Frequency ◽  
Neuro Fuzzy ◽  
Interior Permanent Magnet ◽  
Application Specific Integrated Circuit ◽  
Computer Processor ◽  
Application Specific

Concepts of the electronically-controlled electromechanical/mechanoelectrical Steer-, Autodrive- and Autoabsorbable Wheels (SA2W) with their brushless Alternating Current-to-Alternating Current (AC-AC), Alternating Current-to-Direct Current-Alternating Current (AC-DC-AC) and/or Direct Current-to-Alternating Current (DC-AC)/Alternating Current-to-Direct Current (AC-DC) macroelectronic converter commutator (macro-commutator) wheel-hub motors/generators with the Application Specific Integrated Matrixer (ASIM) macroelectronic converter commutators (ASIM macrocommutators) and Application Specific Integrated Circuit (ASIC) microelectronic Neuro-Fuzzy (NF) computer (processor) controllers (ASIC NF microcontrollers) for environmentally-friendly tri-mode supercars (advanced ultralight hybrids) have been conceived by the first author and designed by both authors with the Cracow University of Technology’s Automotive Mechatronics Research and Development (R&D) Team. These electromechanical/mechanoelectrical wheel-hub motors/generators, respectively, for instance, can be composed of the outer rotor with the Interior Permanent Magnet (IPM) poles and the inner stator that has the three-phase armature winding. The macroelectronic converter commutator establishes the AC-AC cycloconverter, AC-DC rectifier-DC-AC inverter and/or DC-AC inverter/AC-DC rectifier ASIM macrocommutator. The microelectronic NF computer (processor) controller establishes the ASIC microcomputer-based NF microcontroller. By adopting continuous semiconductor bipolar electrical valves in the high-power ASIM, it has been able to increase the commutation (switching) frequency and reduce harmonic losses of the electromechanical/mechanoelectrical wheel-hub motors/generators, respectively.

Alginate/Bioglass® composite coatings on stainless steel deposited by direct current and alternating current electrophoretic deposition

2013 ◽  
Vol 233 ◽  
pp. 49-56 ◽  
Author(s):  
Qiang Chen ◽  
Luis Cordero-Arias ◽  
Judith A. Roether ◽  
Sandra Cabanas-Polo ◽  
Sannakaisa Virtanen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Electrophoretic Deposition ◽  
Direct Current ◽  
Composite Coatings ◽  
Alternating Current

scholarly journals The Effect of AC (alternating current) and DC (direct current) on Bend Testing Results of Low Carbon Steel Welding Joints

Teknomekanik ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 56-61
Author(s):  
Zetri Firmanda ◽  
Abdul Aziz ◽  
Bulkia Rahim
Keyword(s):  
Carbon Steel ◽  
Direct Current ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Alternating Current ◽  
Bend Test ◽  
Open Crack ◽  
Low Carbon ◽  
Bend Testing ◽  
Welding Joints

The purpose of this study was to determine the effect of alternating current (AC) and direct current (DC) on the bend testing results of low carbon steel welding joints. The results of this study are expected to determine the cracks that occur from the root bend and face bend testings in the AC and DC welding process. This study used experimental method, where the research was done by giving AC and direct polarity DC (DC-) SMAW welding treatments. The material used in this research was low carbon steel plate DIN 17100 Grade ST 44, thickness 10 with E7016 electrode type. The process of welding joints used a single V seam, strong current of 90A, and the welding position of 1G. The testing of welding joints was carried out by bend testing using the standard acceptance of AWS D1.1 root bend and face bend testing results. The results of the bend testing showed that the AC welding root bend test specimen held no cracks while the DC welding root bend test held cracks with incompelete penetration and open crack defects. On the contrary, the AC welding face bend test had open crack defects and in the DC welding face bend test was found a crack. Thus, there was a difference in the crack resistance of the welding joint from the types of current used through the root bend test and face bend test. Therefore, it can be summarized that AC welding is better for root welding and DC welding is good for capping welding.

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