Abstract: A mixed potential sensor device and methods for measuring total ammonia (NH3) concentration in a gas is provided. The gas is first partitioned into two streams directed into two sensing chambers. Each gas stream is conditioned by a specific catalyst system. In one chamber, in some instances at a temperature of at least about 600° C., the gas is treated such that almost all of the ammonia is converted to NOx, and a steady state equilibrium concentration of NO to NO2 is established. In the second chamber, the gas is treated with a catalyst at a lower temperature, preferably less than 450° C. such that most of the ammonia is converted to nitrogen (N2) and steam (H2O). Each gas is passed over a sensing electrode in a mixed potential sensor system that is sensitive to NOx. The difference in the readings of the two gas sensors can provide a measurement of total NH3 concentration in the exhaust gas. The catalyst system also functions to oxidize any unburned hydrocarbons such as CH4, CO, etc.

Abstract: The present invention is disclosed herein as an electrochemical cell having a cell housing with a first half cell and a second half cell, and an ion selective membrane between the cells. The electrochemical cell further has a first electrode positioned within the first half cell, a second electrode positioned within the second half cell, an electrolyte in electrical communication with both the first electrode and the second electrode. The electrodes of the cell are configured so that the electrochemical cell maintains a substantially constant salt concentration level throughout operation. The cell is preferably used in conjunction with an implantable fluid delivery apparatus. A method for using the device is additionally disclosed.

Abstract: A multi-phase mixed protonic/electronic conducting material comprising a proton-conducting ceramic phase and an electron conductive ceramic phase. Under the presence of a partial pressure gradient of hydrogen across the membrane, a membrane fabricated with this material selectively transports hydrogen ions through the protonically conductive ceramic phase and electrons through the electronically conducting ceramic phase, which results in ultrahigh purity hydrogen permeation through the membrane. The material has a high electronic conductivity and hydrogen gas transport is rate-limited by the protonic conductivity of the material.

Abstract: An improved gas diffusion electrode composed of a perovskite-type oxide dispersed in a mixture of carbon black and a hydrophobic binder polymer. An improved catalyst for use in the electrochemical reduction of oxygen comprising a perovskite-type compound having alpha and beta sites, and having a greater molar ratio of cations at the beta site. A particularly good reduction catalyst is a neodymium calcium manganite. An improved method of dispersing the catalysts with carbon in a reaction layer of the electrode improves performance of the electrode and the oxygen reduction process. This is provided by adding carbon black to an aqueous solution of metal salts before it is heated to a gel and then to a char and then calcined. Optionally, a quantity of the desired oxide catalyst can be premixed with a portion the carbon before adding the carbon to an aqueous solution of the metal salts to be heated.

Abstract: The present invention is a method and apparatus for measuring the total NOx concentration in a gas stream utilizing the principles of a NOx sensor, i.e., mixed potential sensor. The exhaust gas is first conditioned by a catalyst assembly that converts the various species of nitrogen oxide gases present to a fixed steady state concentration ratio of NO2/NO, where NO2 is approximately 0–10% of the total NOx concentration present in the gas exhaust, thereby enabling the NOx sensor to generate a meaningful and reproducible determination of the concentration of total NOx present in the gas being measured. The catalyst assembly also functions to oxidize any unburned combustibles such as CH4, CO, etc., and remove potential contaminants such as SO2.

Abstract: A sanitizing device comprising: a sanitizing component for sanitizing a surface, liquid, gas, and/or associated surrounding environment, wherein the sanitizing component includes an electrochemical, chemical, and/or corona cell; and a housing for retaining the sanitizing component. A particulate filtering component capable of substantially trapping particulates thereon and fragrance emitting means are also provided.