To protect the atmosphere, it has been suggested that hydrogen be used as a fuel in aircraft that fly at high elevations. This would avoid the formation of carbon dioxide and other carbon-based combustion products. The combustion chamber of a Brayton cycle operates at about 400 kPa at these altitudes. Assume that new materials that allow for a maximum temperature of 2600 K are available, and the atmospheric composition at these altitudes is 21 percent oxygen and 79 percent nitrogen by volume. The presence of NO_x in the exhaust gases is critical at these altitudes and cannot exceed 0.1 percent by volume. Excess air supply is used to control the maximum temperature of the combustion process. Determine the quantity of excess air to be used so that neither the maximum temperature nor the maximum allowable NOx specification is exceeded. What is the NOx mole fraction if the maximum temperature specification governs? If the NOx specification governs, what is the temperature of the combustion gases?