Abstract: An electrostatic charging air cleaning device. The device includes a pre-charger configured to generate a corona discharge to electrostatically charge particulate matter in an air stream. The device further includes a separator downstream from the pre-charger configured to convey the electrostatically charged particulate matter and formed of an insulative material. The device also includes a collection electrode configured to receive and to absorb the conveyed electrostatically charged particulate matter. The collection electrode includes a substrate material and a coating layer coated onto the substrate material. The coating layer includes a carbon black material and a polymeric binder. The substrate material is a metal plate including mechanical perforations.

Abstract: A method of monitoring and replacing fuel cells within a fuel cell stack assembly. The method includes measuring one or more operating conditions of a fuel cell within the fuel cell stack assembly. The method includes determining, using a processor, a state of health of the fuel cell based at least in part on the one or more operating conditions. The method includes detaching the fuel cell from an adjacent cell within the fuel cell stack assembly by removing a first electrically-conducing mating matrix associated with a first endplate of the fuel cell from a second electrically-conducing mating matrix associated with a second endplate of the adjacent cell. The method includes attaching a replacement fuel cell by mating a third electrically-conducing mating matrix associated with a third endplate of the replacement fuel cell with a fourth electrically-conducing mating matrix associated with a fourth endplate of the adjacent cell.

Abstract: Fuel cell alloy bipolar plates. The alloys may be used as a coating or bulk material. The alloys and metallic glasses may be particularly suitable for proton-exchange membrane fuel cells because of they may exhibit reduced weights and/or better corrosion resistance. The alloys may include any of the following AlxCuyTiz, AlxFeyNiz, AlxMnyNiz, AlxNiyTiz, CuxFeyTiz, CuxNiyTiz, AlxFeySiz, AlxMnySiz, AlxNiySiz, NixSiyTiz, and CxFeySiz. The alloys or metallic glass may be doped with various dopants to improve glass forming ability, mechanical strength, ductility, electrical or thermal conductivities, hydrophobicity, and/or corrosion resistance.

Abstract: A method of forming a collection electrode for an electrostatic charging air cleaning device. The method includes forming a slurry including a carbon black powder material, a polymeric binder material and a liquid solvent material. The method further includes applying the slurry to a substrate material. The method also includes curing the slurry to obtain a coating layer on the substrate material to form the collection electrode.

Abstract: A movable ballast system for an aircraft includes first and second ballast docks secured to the aircraft. The first ballast dock includes a first housing and a first ballast tray secured within the first housing. The first ballast tray includes a plurality of channels. The second ballast dock is positioned aft of a CG of the aircraft and includes a second housing and a second ballast tray secured within the second housing. The second ballast tray includes a plurality of channels. The movable ballast system includes a plurality of movable ballasts, each movable ballast of the plurality of movable ballasts being configured to fit within at least one channel of each of the plurality of channels of the first and second ballast trays.

Abstract: A unit cell for a fuel cell stack including an anode catalyst layer separated by a polymer electrolyte membrane from a cathode catalyst layer, a first cell end plate separated by a first gas diffusion layer from the anode catalyst layer, and a second cell end plate separated by a second gas diffusion layer from the cathode catalyst layer, wherein the first cell end plate, the second cell end plate, or both include a matrix of electrically-conducting protrusions thereof.

Abstract: A computational method for simulating the motion of elements within a multi-element system using a neural network force field (NNFF). The method includes receiving a combination of a number of rotationally-invariant features and a number of rotationally-covariant features of a local environment of the multi-element system; and predicting a force vector for each element within the multi-element system based on the combination of the number of rotationally-invariant features, the number of rotationally-covariant features, and the NNFF, to obtain a simulated motion of the elements within the multi-element system.

Abstract: Systems and techniques for automated voice assistant personality selector are described herein. A task may be identified that is to be completed by a user of a voice-enabled virtual assistant. A response may be output in connection with the task using a default personality for the voice-enabled virtual assistant selected based on the task. A task completion checkpoint may be determined for the task. It may be identified that the task completion checkpoint has not been reached. A personality profile of the user may be compared to personality data of a set of voice-enabled virtual assistant profiles corresponding to respective members of a set of available voice personalities for the voice-enabled virtual assistant. An escalation personality may be selected for the voice-enabled virtual assistant based the comparison and the task. Commands for facilitating user completion of the task may be transmitted via the voice-enabled virtual assistant using the selected escalation personality.

Abstract: An anticorrosive and conductive substrate includes a bulk portion and a surface portion including a magnesium titanium material having a formula (I) TixMg1-xOy (I), where x is a number from 0 to ?1 and y is a number from 1 to ?2, and wherein at least about 50% of the magnesium titanium material has a cubic crystal structure, and wherein the magnesium titanium material is configured to impart anticorrosive and conductive properties to the substrate.

Abstract: A catalyst support material for a proton exchange membrane fuel cell (PEMFC). The catalyst support material includes a metal material of an at least partially oxidized form of TiNb3O6 reactive with H3O+, HF and/or SO3? to form reaction products in which the metal material of the at least partially oxidized form of TiNb3O6 accounts for a stable molar percentage of the reaction products.

Abstract: A proton-exchange-membrane fuel cell bipolar plate includes a metal substrate having a bulk portion and a surface portion including an anticorrosive, conductive binary phosphide material having a formula (I): AxPy??(I), where A is an alkali metal, alkaline earth metal, transition metal, post-transition metal, or metalloid, x, y is each a number independently selected from 1 to 15, and the binary phosphide material is configured to impart anticorrosive and conductive properties to the metal substrate.

Abstract: A method of applying a coating to a flow field plate of a fuel cell. The method includes applying a solution including a metal-containing precursor and a solvent to at least a portion of a surface of a flow field plate, and evaporating the solvent to form a coating on the at least the portion of the surface of the flow field plate.

Abstract: A polyelemental catalyst structure. The structure includes a region formed of a first metal material, a first core region formed of a second metal material, and a second core region formed of a third metal material. The first core region has interfacial contact with the region. The second core region has interfacial contact with the first core region. The polyelemental catalyst structure includes platinum (Pt), a first metal MI, a second metal MII and a third metal MIII. The first metal MI is configured to enhance catalytic activity of Pt. The second metal MII is configured to enhance stability of the polyelemental catalyst structure. The third metal MIII is configured to enhance covalent bonding between Pt, the first metal MI, the second metal MII and/or the third metal MIII.

Abstract: A method for treating a metal material to make a surface portion hydrophobic. The method includes oxidizing an untreated surface portion of the metal material to form an oxidized surface portion. The untreated surface portion has metal atoms. The oxidizing step forming bonds between the metal atoms and oxygen atoms. The method further includes doping the oxidized surface portion with a liquid containing a fluorine-containing salt to form a fluorinated surface portion. The doping step forming bonds between fluorine atoms and at least a portion of the metal atoms and the oxygen atoms. The fluorinated surface portion is hydrophobic.

Abstract: Systems and techniques for voice enabled assistant for community demand fulfillment are described herein. A community of user devices may be identified that are registered with a voice-based supply and demand matching service. A supply of an item may be determined based on first user audio collected from a first user device of the community of user devices. A demand for the item may be determined based on second user audio collected from a second user device of the community of user devices. An indication of the supply may be transmitted to a user of the second user device.

Abstract: A method of adjusting a center of gravity (CG) of an aircraft includes: inputting at least one load parameter into a flight computer, determining, via a processer of the flight computer, the CG of the aircraft. Responsive to a determination by the processor that the CG is outside of a CG envelope, moving at least a first movable ballast of a plurality of movable ballasts from a first ballast dock to a second ballast dock to move the CG toward the CG envelope. Each of the first and second ballast docks may include a housing and a first ballast tray secured within the housing and comprising a plurality of channels.

Abstract: A fuel cell catalyst system includes a catalyst and a catalyst support material binding the catalyst and including an anticorrosive, conductive material having oxygen vacancies and a formula (I): MgTi2O5-???(I), where ? is any number between 0 and 3 optionally including a fractional part denoting the oxygen vacancies, the material having an electronic conductivity of about 2-10 S/m at room temperature in an ambient environment.

Abstract: A fuel cell bipolar plate (BPP) includes a metal substrate having a bulk portion and a surface portion comprising an anticorrosive, conductive material having oxygen vacancies and a formula (I): MgTi2O5-???(I), where ? is any number between 0 and 3 optionally including a fractional part denoting the oxygen vacancies, the material having an electronic conductivity of about 2-10 S/m at room temperature in an ambient environment.

Abstract: An electrostatic charging air cleaning device having first and second pre-chargers. The first pre-charger is configured to generate a first corona discharge to electrostatically charge PM in the incoming air stream with a first charge to form a first exiting air stream exiting the first pre-charger. The second pre-charger is configured to generate a second corona discharge to electrostatically charge PM in the incoming air stream with a second charge to form a second exiting air stream exiting the second pre-charger. The device also includes a separator having apertures such that PM in the second exiting air stream passes through the separator to agglomerate with PM in the first exiting air stream to form agglomerated particles. The apertures are sized such that the agglomerated particles are larger than the apertures to preclude the agglomerated particles from reentering the second exiting air stream.

Abstract: A hydrogen gas storage tank includes a body including a steel bulk region and a passivating metal oxide layer adjacent to the steel bulk region, the oxide layer comprising a number of metal oxide molecules, all having a morphology, wherein at least about 51 wt. % of the number of metal oxide molecules are Fe2O3 molecules having morphologies of (012), (001), and/or (110) surface facets such that the oxide layer is configured to lower hydrogen adsorption into the steel bulk region by at least 25% compared to a steel bulk region free from the passivating metal oxide layer.