6624 results about "Gas concentration" patented technology

This invention provides an apparatus and method for injecting gas within a plasma reactor and tailoring the distribution of an active species generated by the remote plasma source over the substrate or wafer. The distribution may be made more or less uniform, wafer-edge concentrated, or wafer-center concentrated. A contoured plate or profiler is provided for modifying the distribution. The profiler is an axially symmetric plate, having a narrow top end and a wider bottom end, shaped to redistribute the gas flow incident upon it. The profiler is situated below an input port within the plasma reactor chamber and above the wafer. The method for tailoring the distribution of the active species over the substrate includes predetermining the profiler diameter and adjusting the profiler height over the substrate. A coaxial injector tube, for the concurrent injection of activated and non-activated gas species, allows gases (or gas mixtures) to be delivered in an axially symmetric manner whereby one gas can be excited in a high density RF plasma, while the other gas can be prevented from excitation and / or dissociation caused by exposure to the plasma or heated surfaces in the source apparatus. The gas admixture that is not to be excited or dissociated prior to contact with the wafer surface is shielded from direct exposure to the RF field surrounding the plasma confinement tube. The tube walls are also shielded from the infrared energy emitted from the plasma. The profiler is used in conjunction with the coaxial injector tube for redistributing the excited gases emerging from the injector tube, while allowing the non-excited gases to pass through its center.

An indirect calorimeter for measuring the metabolic rate of a subject includes a respiratory connector configured to be supported in contact with the subject so as to pass inhaled and exhaled gases as the subject breathes, a flow pathway, and a hygiene barrier positioned to block a predetermined pathogen from the exhaled gases. The indirect calorimeter also includes a flow pathway having a first end in fluid communication with the respiratory connector and a second end in fluid communication with a source and sink for respiratory gases. The flow pathway includes a flow tube through which the inhaled and exhaled gases pass, an outer housing surrounding the flow tube, and a chamber disposed between the flow tube and the first end. The indirect calorimeter also includes a flow meter configured to generate electrical signals as a function of the instantaneous flow volume of inhaled and exhaled gases passing through the flow pathway, and a component gas concentration sensor operable to generate electrical signals as a function of the instantaneous fraction of a predetermined component gas in the exhaled gases as the gases pass through the flow pathway. The indirect calorimeter further includes a computation unit operable to receive the electrical signals from the flow meter and the concentration sensor and operative to calculate at least one respiratory parameter for the subject as the subject breathes through the calorimeter.

A nitrogen oxide concentration detector has a first measurement chamber 2 into which is introduced a measurement gas via a first diffusion resistance 1; an oxygen concentration detection electrode 7a for measuring the oxygen concentration in the measurement gas in said first measurement chamber 1; a first oxygen ion pump cell 6 for pumping out oxygen in the measurement gas from said first measurement chamber 2 based on the potential of said oxygen concentration detection electrode 7a; a second measurement chamber 8 into which the gas is introduced from said first measurement chamber 2 via a second diffusion resistance 3; and a second oxygen ion pump cell 8 having a pair of electrodes 8a,8b across which a voltage is applied to decompose NOx in the second measurement chamber 4 to pump out dissociated oxygen to cause a circuit Ip2 corresponding to the NOx concentration to flow in the second oxygen ion pump cell 8. Variation of NOx concentration is a function of variation of Ip2. The concentration obtained based on the Ip2 is corrected responsive to the oxygen concentration in the measurement gas. Particularly, a coefficient of the variation of the Ip2, gain, in said function is corrected responsive to the oxygen concentration in the measurement gas.