Abstract: A method and system for detecting and preventing a fraudulent request for mobile telephone service to be provided to a mobile subscriber by one of a plurality of serving carrier mobile networks in one of a plurality of roaming markets subject to fraud includes a first database storing home/serving market identification codes and a second database storing authorized subscriber identification data. A monitoring device monitors communication data in response to a power-on signal transmitted by the mobile telephone unit. A central server then determines if the subscriber is authorized to receive service in the roaming market based on the communication data, the home/serving market identification codes stored in the first database, and the authorized subscriber identification data stored in the second database.

Abstract: A heater mechanism incorporating a thermoelectric converter for use with a self-powered, solid, liquid or gaseous fueled, heater. During operation of the heater mechanism the thermoelectric converter supplies sufficient electrical power to (a) sustain the heater in operation, (b) maintain the starter battery at full charge, and (c) provide auxiliary power to remove and transport heat to desired locations away from the heater. The converter is a highly compact design (high power output per unit volume of space) and lends itself to high volume (mass production) and automated assembly techniques to produce it inexpensively. The thermoelectric converter is made of fewer components than prior art devices. A number of components in the thermoelectric stack serve dual or even multi-functions. The thermoelectric stack components are bonded or mounted together in such a manner as to permit handling as a unit.

Abstract: A method of purifying crude pyrethrum extract through the use of acetonitrile as the extracting agent comprising the method steps of mixing crude pyrethrum extract with acetonitrile, separating the acetonitrile-pyrethrum extract layer at a temperature effective to precipitate out undesirable impurities and waxes in such acetonitrile-pyrethrum extract, removing the acetonitrile by distillation, mixing the concentrated pyrethrum extract with an amount of mineral spirits effective to precipitate out undesirable impurities, and removing the mineral spirits by distillation.