Abstract: A spark plug designed for fitting in tight spaces of an engine compartment is disclosed. The spark plug has a conductive terminal attached to one end of a flexible central electrode and has a ceramic insulator partially encasing the flexible central electrode. The part of the flexible central electrode between the ceramic insulator and the conductive terminal is encased in a flexible insulator. The flexible part of the central electrode may be bent away from the axis of the ceramic insulator accommodating both installation and servicing of the spark plug in tight spaces.

Abstract: A spark plug designed for fitting in tight spaces of an engine compartment is disclosed. The spark plug has a conductive terminal attached to one end of a flexible central electrode and has a ceramic insulator partially encasing the flexible central electrode. The part of the flexible central electrode between the ceramic insulator and the conductive terminal is encased in a flexible insulator. The flexible part of the central electrode may be bent away from the axis of the ceramic insulator accommodating both installation and servicing of the spark plug in tight spaces.

Abstract: A process for constructing a three-dimensional geologic model of a subsurface earth volume wherein resolution scales of multiple diverse data types, including seismic data, are accounted for by generating multiple frequency passband models and combining them together to form the complete geologic model. Preferably, a model is generated for each of a low-frequency passband, a mid-frequency passband, and a high-frequency passband. When integrating seismic data into the modeling process, the seismic-frequency passband constitutes the mid-frequency passband model. The process further contemplates updating tentative frequency-passband models through optimization of assigned rock property values in each tentative model according to specified geological criteria. Such optimization is carried out by perturbation of the rock property values in a manner wherein the frequency content of each model is maintained.