Search NASA⌕ Search

SEARCH · Search NASA

Results for “CONDUCTOR”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8

Fuel-Cell Electrolytes Based on Organosilica Hybrid Proton Conductors

A new membrane composite material that combines an organosilica proton conductor with perfluorinated Nafion material to achieve good proton conductivity and high-temperature performance for membranes used for fuel cells in stationary, transportation, and portable applications has been developed. To achieve high proton conductivities of the order of 10(exp -1)S/cm over a wide range of temperatures, a composite membrane based on a new class of mesoporous, proton-conducting, hydrogen-bonded organosilica, used with Nafion, will allow for water retention and high proton conductivity over a wider range of temperatures than currently offered by Nafion alone. At the time of this reporting, this innovation is at the concept level. Some of the materials and processes investigated have shown good proton conductivity, but membranes have not yet been prepared and demonstrated.

Narayan, Sri R.↗

Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

Berger, Pascal↗

Characterizing the In-Phase Reflection Bandwidth Theoretical Limit of Artificial Magnetic Conductors With a Transmission Line Model

We validate through simulation and experiment that artificial magnetic conductors (AMC s) can be well characterized by a transmission line model. The theoretical bandwidth limit of the in-phase reflection can be expressed in terms of the effective RLC parameters from the surface patch and the properties of the substrate. It is found that the existence of effective inductive components will reduce the in-phase reflection bandwidth of the AMC. Furthermore, we propose design strategies to optimize AMC structures with an in-phase reflection bandwidth closer to the theoretical limit.

Xie, Yunsong↗

Development and Characterization of Lightweight Durable Composite Conductor for Cables

Sustainable aviation in the form of electrified propulsion is likely to lead to an increase in the electrical assets contained within a single aircraft. As a result, it is desirable to design light weight conductor materials, thus reducing the payload of components like motor windings, low voltage signal cables, and transmission cables for data and power. One approach involves replacing pure Cu wiring with metalized CNT composites. This paper evaluates a framework for modeling overall conductivity and current sharing within such composites. Processing methods and parameters were refined. Select electroplated samples outperformed pure Cu in conductivity and had comparable ultimate tensile strengths. Tensile strengths are expected to improve with an additional densification step during processing. Acoustic emission data was used to predict the failure mechanism of the composite. Theories explaining improved intrinsic conductivity are discussed, with a focus on chemical and mechanical interactions at the Cu-CNT interface. These include Cu infiltration of CNT crevices, CNT oxidation, activity at defects in CNT walls, and the release of carbide-forming metals from CNT walls. Validating any or all these theories will require further work replicating data, collecting electron micrographs and conducting chemical analyses.

Metalized CNT↗

Leakage tester for flat conductor cable connector

U-tube containing liquid indicates pressure differences in a leakage tester. This tube, connecting two containers, indicates that the amount of leakage over a set period of time is calculated from the pressure and gas volume.

Angele, W.↗

Flat conductor cable connector with contact separation seal

Cable connector is developed in which each pair of contact elements is isolated by plastic cells and the mating interface is sealed by an elastic gasket. So insulated, the connector may be operated under high vacuum conditions at voltages up to 600 V ac without electrical leakage or intercontact ionization.

Angele, W.↗