An improved cartridge structure that both heats the materials contained therein and provides for enhanced structure such that the bypass leaking of the low viscosity heated components is avoided. The cartridge is preferably formed from a rigid material such as reinforced fiberglass tubing. The wall of the cartridge is then wrapped in a flexible heating element or has a heating element cast directly in the wall thereof. The heating elements preferably heat the interior contents and epoxy cartridges to between 150 degrees and 180 degrees Fahrenheit. The wall structure may be of single wall construction with the heaters embedded therein or of a double wall construction such that the heaters are contained between an inner and outer wall. Further the wall construction is preferably formed to withstand the pressures applied when spray applying the epoxy contained therein to prevent the tube wall deformation and resulting blow by leakage.

An improved cartridge structure that both heats the materials contained therein and provides for enhanced structure such that the bypass leaking of the low viscosity heated components is avoided. The cartridge is preferably formed from a rigid material such as reinforced fiberglass tubing. The wall of the cartridge is then wrapped in a flexible heating element or has a heating element cast directly in the wall thereof. The heating elements preferably heat the interior contents and epoxy cartridges to between 150 degrees and 180 degrees Fahrenheit. The wall structure may be of single wall construction with the heaters embedded therein or of a double wall construction such that the heaters are contained between an inner and outer wall. Further the wall construction is preferably formed to withstand the pressures applied when spray applying the epoxy contained therein to prevent the tube wall deformation and resulting blow by leakage.

An electronic cigarette particularly adaptable to vaporize liquid material also having exhale filter function is disclosed herein. The exhale function is useful to prevent second hand smoke in an enclosed environment, for example. An innovative diverter valve assembly comprises a unique duckbill valve configuration diverting air through a cooker chamber and into a mouthpiece in an inhale function and diverting exhaled air around the cooker chamber in the exhale function and through a filter assembly. A preferred embodiment further introduces a unique shape to the smoking instrument being elliptical in the cross-section and tapering to proximal and distal ends.

An electronic cigarette particularly adaptable to vaporize liquid material also having exhale filter function is disclosed herein. The exhale function is useful to prevent second hand smoke in an enclosed environment, for example. An innovative diverter valve assembly comprises a unique duckbill valve configuration diverting air through a cooker chamber and into a mouthpiece in an inhale function and diverting exhaled air around the cooker chamber in the exhale function and through a filter assembly. A preferred embodiment further introduces a unique shape to the smoking instrument being elliptical in the cross-section and tapering to proximal and distal ends.

A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500 C. and about 800 C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500 C. and about 800 C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

A welding apparatus for a fibre reinforced resin based material comprises an elongate flexible heat conductive strip and an elongate heat sink extending around at least a portion of the perimeter of the conductive strip. The elongate heat sink is divided into a plurality of segments wherein adjacent segments can move relative to one another.

A welding apparatus for a fibre reinforced resin based material comprises an elongate flexible heat conductive strip and an elongate heat sink extending around at least a portion of the perimeter of the conductive strip. The elongate heat sink is divided into a plurality of segments wherein adjacent segments can move relative to one another.