Field emission cathodes are presently being developed as low-power space electric propulsion neutralizers and for spacecraft charge control and electrodynamic tether applications requiring no consumables. These cathodes effect cold electron emission by the application of a relatively high electric field across a small gap from some kind of electron emitting (cathode) surface. Various designs of...

Tritium up to fifty times background has been observed upon electrolyzing 1N D2SO4 in four out of four cells when using Pd cathodes "of a certain type". No tritium was detected in four control cells, containing H2S04 in H2O, employing Pd cathodes cut from the same wire spool. Tritium amounts were from 7 x 10 to 2.1 × 10 atoms, corresponding to average generation rates from 5.1 × 10 to 2 × 10 at...

Air cathode microbial fuel cells (MFCs) were used in a cascade-system, to treat neat human urine as the fuel. Their long-term operation caused biodeterioration and biofouling of the cathodes. The cathodes were made from two graphite-painted layers, separated by a current collector. The initial performance of the MFCs was reaching average values of 105.5 ± 32.2 μW and current of 1164.5 ± 120.2 μ...

Using Ti-Pt electrodes in closed electrolytic cells containing D2O-H2SO4 electrolyte, evidence for excess thermal power generation has been observed (i.e. Power out – Power in > 0). It had been noted that experiments (8-cell) with smaller cathodes (larger perimeter to area ratio) performed better than experiments (SEC system) in which larger cathodes (smaller perimeter to area ratio) were used....

Carbon Nano Tubes (CNT’s) as field-emitters have been investigated for more than two decades and can produce relatively low emittance electron beams for a given cathode size. Unlike thermionic cathodes, CNT cathodes are able to produce electrons at room temperature and relatively low electric field (a few MV/m). In collaboration with FermiLab, we have recently tested CNT cathodes both with DC a...

Microstructural characteristics of porous LSM/YSZ composite cathodes greatly influence the performance of solid oxide fuel cells. The triple phase boundaries, for example, account for a significant portion of the electrochemically active sites in these porous composite cathodes. Nonetheless, experimental characterization of the relevantmicrostructural attributes has been problematic due to lack...

Cobalt substituted lithium–nickel oxides were synthesized by a solid-state reaction procedure using lithium nitrate, nickel hydroxide and cobalt oxalate precursor and were characterized as cathodes for molten carbonate fuel cell (MCFC). LiNi0.8Co0.2O2 cathodes were prepared using non-aqueous tape casting technique followed by sintering in air. The X-ray diffraction (XRD) analysis of sintered Li...

Hollow cathodes are electron sources used for the gas ionization and the beam neutralization in both ion and Hall effect thrusters (HETs). A reduction of power and propellant consumption from the cathode is particularly needed in small satellite applications, where power and mass budgets are inherently limited. Concurrently, the interest in high-power HETs is increasingly fostered for a number ...

Different polymorphs of MnO2 (α-, β-, and γ-) were produced by microwave hydrothermal synthesis, and graphene oxide (GO) nanosheets were prepared by oxidation of graphite using a modified Hummers' method. Freestanding graphene/MnO2 cathodes were manufactured through a vacuum filtration process. The structure of the graphene/MnO2 nanocomposites was characterized using X-ray diffraction (XRD) and...

Methane is the primary end product from cathodic current in microbial electrolysis cells (MECs) in the absence of methanogenic inhibitors, but little is known about the archaeal communities that develop in these systems. MECs containing cathodes made from different materials (carbon brushes, or plain graphite blocks or blocks coated with carbon black and platinum, stainless steel, nickel, ferri...