Abstract: A method and a detector for detecting nitrogen oxide in test gas are provided wherein test gas which contains NOx and interference gases is supplied through an oxygen feeder 4 into a measuring chamber 1a, and the interference gases are oxidized by oxygen or oxygen ion supplied to the measuring chamber 1a through oxygen feeder 4. A total amount of NOx in the test gas is detected based on a level of EMF produced between a first electrode 2 for detecting oxygen and NO2 gas and a second electrode 3 for detecting oxygen.

Abstract: The present invention relates to an aluminum alloy powder.Aluminum alloy powder having a high Si content is known but its heat resistance, wear resistance, and strength are poor.The aluminum alloy powder according to the present invention is characterized in that it contains from approximately 10.0% to approximately 30.0% of silicon and at least one element selected from the group consisting of from approximately 5.0% to approximately 15.0% of nickel, from approximately 3.0% to approximately 15.0% of iron, and from approximately 5.0% to approximately 15.0% of manganese, the silicon crystals in the aluminum alloy powder being 15 .mu.m or less in size. Due to the high content of nickel, iron, and manganese, the matrix is hardened and strengthed by the presence of finely dispersed intermetallic compounds and the silicon crystals, and thereby the high-temperature characteristics are improved.The shaped body, e.g.

Abstract: A novel group of iron-base sintered alloys especially suitable for valve seat manufacture having excellent wear resistance and good machinability is provided. The alloy is produced by a combination of specific atomized pre-alloyed powder, iron powder and graphite powder by compacting and sintering processes. Various manufacturing methods with or without infiltration of filler materials into pores in the sintered product to improve wear resistance and machinability are disclosed.