Abstract: A method of bonding two electrically conductive substrates together includes the steps of forming a dielectric layer between the substrates, with the layer being formed from a sol-gel solution. Through the application of a constant voltage an ionic depletion region is created in the dielectric layer. After the step of creating the ionic depletion region, the dielectric layer and substrates are heated such that an oxygen depletion region is created in one of the substrates. The sol-gel solution includes sodium aluminoborosilicate having about 75-90 mol % SiO.sub.2, about 5-20 mol % B.sub.2 O.sub.3, about 1-10 mol % Na.sub.2 O and about 0-5 mol % Al.sub.2 O.sub.3.

Abstract: A spark-excited fluorescence sensor (10) is provided which enables monitoring of various gas species (14), such as H.sub.2, CO.sub.x, NO.sub.x, N2, NH.sub.x and hydrocarbons added to a system as source fuels and/or additive agents, or discharged from a system as exhaust including pollutants, for more efficient use of fuels for optimizing performance of the system, and, also, for reducing pollutants in the atmosphere. The spark-excited fluorescence sensor of the invention comprises a spark plug (12) to excite molecules of the gaseous species, an optical fiber window (18) and an optical fiber bundle (20) to collect and transmit, respectively, the fluorescence, bandpass filters ( 24 ) to select predetermined wavelengths corresponding to the gases to be detected, detectors (26), and signal processor (28 ) . The output from the signal processor is then used to improve overall performance of the system.