A variety of polyhedral nanocages are provided having a hollow interior, ultrathin walls, and well-defined facets of metal atoms. The nanocages can include a variety of precious metals such as Pt, Au, Ru, Rh, or Ir. The metal atoms can take a face-centered cubic structure with {111} facets on the surface. The walls can be thin, sometimes less than 1 nm in thickness or only a few atomic layers in thickness. The nanocages can provide for efficient uses of valuable precious metals, among other things, in catalysis. For example, catalysts are provided exhibiting high mass activities in oxygen reduction reactions. Methods of making and methods of using the nanocages and catalysts are also provided.

An elastomeric cell frame for a fuel cell includes an insert which includes: a membrane electrode assembly including a polymer electrolyte membrane and a pair of electrode layers respectively disposed on opposite sides of the polymer electrolyte membrane; and a pair of gas diffusion layers disposed and bonded on upper and lower surfaces of the membrane electrode assembly, respectively. The insert further includes an elastomeric frame disposed in an external region of the insert. The elastomeric frame surrounds one of opposite edge surfaces of the insert and a side surface of the insert, the elastomeric frame being interface-bonded, through thermal bonding, to portions of the polymer electrolyte membrane and the electrode layers exposed at the one of opposite edge surfaces of the insert and the side surface of the insert.

A cooling control method of a fuel cell is provided. The method includes estimating a temperature of a separator based on heat exchange between the separator formed between unit cells of a fuel cell stack and coolant flowing through a cooling line between the separators. A ratio of coolant passing through a heat exchange device to coolant bypassing the heat exchange device is adjusted based on the estimated temperature of the separator. Additionally, a rotation speed of a pump for circulating coolant for cooling the fuel cell stack is adjusted based on the estimated temperature of the separator.

An ambient water condenser system is described having a condensation chamber which at least partially contains or surrounds a fluid reservoir which contains a volume or mass of an aqueous hygroscopic solution for condensing water from ambient air and a distillation process for extracting the water from the solution. The fluid reservoir has a heat source, a lower porous hydrophobic membrane, and an upper porous hydrophobic membrane. The heat source causes the hygroscopic solution near the top of reservoir to have a higher temperature which causes it to have a higher water vapor pressure, whereby the water vapor passing through the upper porous hydrophobic membrane and into the condensation chamber condenses into liquid water.

A zinc-iron chloride flow battery relies on mixed, equimolar electrolytes to maintain a consistent open-circuit voltage of about 1.5 V and stable performance during continuous charge-discharge. Considering the good performance relative to the low-cost materials, zinc-iron chloride flow batteries represent a promising new approach in grid-scale and other energy storage applications.

Briefly, a sensor for a continuous biological monitor is provided for measuring the level of a target analyte for a patient. The sensor has a working wire and a reference wire, where the working wire has an analyte limiting layer that passes more than 1 in 1000 analyte molecules from the patient to the an enzyme layer. The enzyme layer has an enzyme entrapped in a polyurethane cross-linked with acrylic polyol. As free electrons are generated, a conductor transfers the electrons to the biological monitor. In some cases, the sensor may be constructed without the use of any expensive platinum.

A liquid recovery device includes: an outer pipe that includes an introduction portion into which a gas-liquid two-phase fluid is introduced; an inner pipe disposed inside the outer pipe at a position where the introduction portion is extended to a downstream side in a flow direction of the gas-liquid two-phase fluid; a double pipe portion that includes a clearance part provided between an inner side of the outer pipe and the inner pipe at a downstream side of the outer pipe in the flow direction; a communication hole that communicates the inner side of the inner pipe with the clearance part; and a drainage portion connected to the clearance part to discharge the liquid-phase fluid flowing into an interior of the clearance part.

A fuel supply control system and method for a fuel cell are disclosed. The system includes: a fuel cell configured to receive a fuel gas and an oxidation gas and generate electric power; a recirculation line configured to circulate gas containing the fuel gas and connected to a fuel electrode of the fuel cell; a discharge valve provided in the recirculation line and configured to allow the gas to be discharged to the outside when open; a discharge amount estimator configured to estimate a discharge amount of the discharged gas based on a supply amount of the fuel gas supplied to the recirculation line, a consumption amount of the fuel gas consumed in the fuel cell, and a change in the amount of the gas in the recirculation line; an offset calculator configured to calculate the discharge amount of the gas estimated by the discharge amount estimator with the discharge valve closed, as a discharge offset; and a controller configured to control opening/closing of the discharge valve.

A method for simulating a phenomenon involving phase change includes: calculating, by a processor, a degree of phase change in a porous medium per unit volume and unit time based on an area of a gas-liquid interface in the porous medium per unit volume and a phase change rate at the gas-liquid interface.

The disclosure relates to an unmanned aerial vehicle, wherein a fuel cell system component provides a structural component of the vehicle. In some instances propulsion modules affixed to wings are oriented so as to provide airflow to plates of a fuel cell via air inlets for each fuel cell provided at the forward surface of each wing, a fuel cell system component forming a portion of the body and wherein the air inlets are unblocked during flight, each propulsion module is configured to provide air as an oxidant to a fuel cell via the air inlets.