Automated High-Ohmic Resistance Bridge With Voltage and Current Null Detection

2013 ◽  
Vol 62 (6) ◽  
pp. 1760-1765 ◽  
Author(s):  
Gert Rietveld ◽  
Jan H. N. van der Beek
1977 ◽  
Vol 42 (2) ◽  
pp. 235-239 ◽  
Author(s):  
D. A. Lathrop ◽  
J. C. Bailey

Microelectrode techniques were used to assess the importance of subthreshold electrotonic interactions between the canine proximal bundle branches and adjacent septal myocardium, and vice versa. Bundle branch action potential duration, maximal rising velocity of phase O, current threshold requirements for all-or-none depolarization, transmembrane voltage, and spontaneous frequency were not altered by adjacent septal muscle activation. Activation of the proximal bundle branches did not change the transmembrane voltage of immediately subjacent muscle cells; likewise, all-or-none activation of ventricular septal muscle did not effect a voltage change in the overlying proximal bundle branches. We conclude that a high ohmic resistance barrier between proximal bundle branch and subjacent muscle precludes significant electrotonic interactions between these neighboring structures.


Author(s):  
Radenka Maric ◽  
Roberto Neagu ◽  
Ye Zhang-Steenwinkel ◽  
Frans P. F. van Berkel ◽  
Bert Rietveld

The key obstacles to the development of low operating temperature (LT) SOFCs are high ohmic resistance and high electrode overpotentials. In the present work, we demonstrate excellent cell performance at 600 °C on a anode supported bi-layer electrolyte SOFC having a thin RSDT-made cerium gadolinium oxide (Gd0.2Ce0.8O2−δ, CGO) and a lanthanum strontium cobaltite (La0.6Sr0.4CoO3−δ, LSC) perovskite cathode. The measured ohmic resistance of the ASE cell with CGO layer deposited by RSDT was 0.24 ohm.cm2, which is close to the expected theoretical value of 0.17 ohm.cm2 for a 5 micron thick 8YSZ electrolyte at 600 °C. This indicates that the obtained peak power output density is approaching what is theoretically possible. This work is based on the lab scale use of Reactive Spray Deposition Technology (RSDT) which is an open atmosphere, cost efficient technique that does not require high vapor precursors and is an effective way to deposit thin ceramic layers of YSZ/CGO/LSC onto Ni-YSZ substrates. It has the potential to chain successive coating steps thus, significantly simplifying the production of multilayered ceramic structures as the SOFCs and reducing the cost associated with manufacturing of the cells.


2013 ◽  
Vol 61 (3) ◽  
pp. 731-735
Author(s):  
A.W. Stadler ◽  
Z. Zawiślak ◽  
W. Stęplewski ◽  
A. Dziedzic

Abstract. Noise studies of planar thin-film Ni-P resistors made in/on Printed Circuit Boards, both covered with two different types of cladding or uncladded have been described. The resistors have been made of the resistive-conductive-material (Ohmega-Ply©) of 100 Ώ/sq. Noise of the selected pairs of samples has been measured in the DC resistance bridge with a transformer as the first stage in a signal path. 1/f noise caused by resistance fluctuations has been found to be the main noise component. Parameters describing noise properties of the resistors have been calculated and then compared with the parameters of other previously studied thin- and thick-film resistive materials.


Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 135
Author(s):  
Yash Dharmendra Raka ◽  
Robert Bock ◽  
Håvard Karoliussen ◽  
Øivind Wilhelmsen ◽  
Odne Stokke Burheim

The ohmic resistances of the anion and cation ion-exchange membranes (IEMs) that constitute a reverse electrodialysis system (RED) are of crucial importance for its performance. In this work, we study the influence of concentration (0.1 M, 0.5 M, 1 M and 2 M) of ammonium bicarbonate solutions on the ohmic resistances of ten commercial IEMs. We also studied the ohmic resistance at elevated temperature 313 K. Measurements have been performed with a direct two-electrode electrochemical impedance spectroscopy (EIS) method. As the ohmic resistance of the IEMs depends linearly on the membrane thickness, we measured the impedance for three different layered thicknesses, and the results were normalised. To gauge the role of the membrane resistances in the use of RED for production of hydrogen by use of waste heat, we used a thermodynamic and an economic model to study the impact of the ohmic resistance of the IEMs on hydrogen production rate, waste heat required, thermochemical conversion efficiency and the levelised cost of hydrogen. The highest performance was achieved with a stack made of FAS30 and CSO Type IEMs, producing hydrogen at 8.48× 10−7 kg mmem−2s−1 with a waste heat requirement of 344 kWh kg−1 hydrogen. This yielded an operating efficiency of 9.7% and a levelised cost of 7.80 € kgH2−1.


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