1. A by-pass gas turbine engine including a primary and a secondary nozzle wherein the primary nozzle is situated radially within, but axially protruding from, the secondary nozzle characterised in that the primary and secondary nozzles have a substantially common central axis along their lengths and the direction of airflow exiting at least one of the primary or secondary nozzles is at an angle to the central axis of the engine and that the direction of airflow exiting each nozzle is at an angle to the other thereby promoting preferential distribution and mixing of the airflows.
2. An engine as claimed in claim 1 wherein the end of both the primary and secondary nozzles are truncated at oblique angles and oriented such that said oblique angles are oppositely orientated.
3. An engine as claimed in claims 2 to 4 wherein said oblique angle is in the range 0.5to 30.
4. An engine as claimed in claim 1 wherein the internal profile of one or both nozzles is arranged such that the airflow leaves the that nozzle at an angle to the axis of the nozzle, said axis taken to be perpendicular to end face of the nozzle.
5. An engine as substantially hereinbefore described with reference the accompanying drawings.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A surgical instrument, comprising:
a handle;
a first conductor;
a second conductor;
an end effector, comprising:
a first jaw;
a second jaw, wherein said first jaw is movable relative to said second jaw in order to capture tissue intermediate said first jaw and said second jaw;
a first electrode electrically coupled with said first conductor; and
a second electrode electrically coupled with said second conductor, wherein said second electrode comprises:
a first layer comprised of a material configured to conduct a first current when a first pressure is applied to said material, and wherein said material is configured to conduct a second current when a second pressure is applied to said material; and
a second layer comprised of a positive temperature coefficient material having a switching temperature, wherein said positive temperature coefficient material comprises a first electrical resistance at a first temperature below said switching temperature and a second electrical resistance at a second temperature above said switching temperature, wherein said second electrical resistance is greater than said first electrical resistance, and wherein said second layer comprises a tissue-contacting surface configured to contact the tissue captured between said first jaw and said second jaw.
2. The surgical instrument of claim 1, wherein said first jaw is movable between an open position, a first position, and a second position, wherein said first jaw is configured to apply said first pressure to said material when said first jaw is in said first position, and wherein said first jaw is configured to apply said second pressure to said material when said first jaw is in said second position.
3. The surgical instrument of claim 1, wherein said first current comprises a first amplitude, wherein said second current comprises a second amplitude, wherein said second pressure is larger than said first pressure, and wherein said second amplitude is larger than said first amplitude.
4. The surgical instrument of claim 1, wherein said material comprises:
a substrate material; and
a conductive material interdispersed within said substrate material in a first volumetric density when said first pressure is being applied to said material and a second volumetric density when said second pressure is being applied to said material, and wherein said second volumetric density is greater than said first volumetric density.
5. The surgical instrument of claim 1, wherein said second resistance is sufficient to inhibit the conduction of electrical current therethrough.
6. The surgical instrument of claim 1, wherein said first electrode is positioned in said first jaw, and wherein said second electrode is positioned in said second jaw.
7. A surgical instrument, comprising:
a handle;
a first conductor;
a second conductor; and
an end effector, comprising:
a first jaw;
a second jaw, wherein said first jaw is movable relative to said second jaw in order to capture tissue intermediate said first jaw and said second jaw;
a first electrode electrically coupled with said first conductor; and
a second electrode electrically coupled with said second conductor, wherein said second electrode comprises:
a first layer comprised of a material configured to conduct a first current when a first pressure is applied to said material, and wherein said material is configured to inhibit current from flowing through said material when a second pressure is applied to said material; and
a second layer comprised of a positive temperature coefficient material having a switching temperature, wherein said positive temperature coefficient material comprises a first electrical resistance at a first temperature below said switching temperature and a second electrical resistance at a second temperature above said switching temperature, wherein said second electrical resistance is greater than said first electrical resistance, and wherein said second layer comprises a tissue-contacting surface configured to contact the tissue captured between said first jaw and said second jaw.
8. The surgical instrument of claim 7, wherein said first jaw is movable between an open position, a first position, and a second position, wherein said first jaw is configured to apply said first pressure to said material when said first jaw is in said first position, and wherein said first jaw is configured to apply said second pressure to said material when said first jaw is in said second position.
9. The surgical instrument of claim 7, wherein said material comprises:
a substrate material; and
a conductive material interdispersed within said substrate material in a first volumetric density when said first pressure is being applied to said material and a second volumetric density when said second pressure is being applied to said material, and wherein said second volumetric density is greater than said first volumetric density.
10. The surgical instrument of claim 7, wherein said second resistance is sufficient to inhibit the conduction of electrical current therethrough.
11. The surgical instrument of claim 7, wherein said first electrode is positioned in said first jaw, and wherein said second electrode is positioned in said second jaw.
12. A surgical instrument, comprising:
a handle;
a first conductor;
a second conductor; and
an end effector, comprising:
a first jaw;
a second jaw, wherein said first jaw is movable relative to said second jaw in order to capture tissue intermediate said first jaw and said second jaw;
a first electrode electrically coupled with said first conductor; and
a second electrode electrically coupled with said second conductor, wherein said second electrode comprises:
a first layer comprised of a material configured to have a first electrical resistance when a first pressure is applied to said material, and wherein said material is configured to have a second electrical resistance when a second pressure is applied to said material; and
a second layer comprised of a positive temperature coefficient material having a switching temperature, wherein said positive temperature coefficient material comprises a first electrical resistance at a first temperature below said switching temperature and a second electrical resistance at a second temperature above said switching temperature which is greater than said first electrical resistance of said positive temperature coefficient material, and wherein said second layer comprises a tissue-contacting surface configured to contact the tissue captured between said first law and said second jaw.
13. The surgical instrument of claim 12, wherein said first jaw is movable between an open position, a first position, and a second position, wherein said first jaw is configured to apply said first pressure to said material when said first jaw is in said first position, and wherein said first jaw is configured to apply said second pressure to said material when said first jaw is in said second position.
14. The surgical instrument of claim 13, wherein said material comprises:
a substrate material; and
a conductive material interdispersed within said substrate material in a first volumetric density when said first pressure is being applied to said material and a second volumetric density when said second pressure is being applied to said material, and wherein said second volumetric density is greater than said first volumetric density.
15. The surgical instrument of claim 13, wherein said second resistance is sufficient to inhibit the conduction of electrical current therethrough.
16. The surgical instrument of claim 13, wherein said first electrode is positioned in said first jaw, and wherein said second electrode is positioned in said second jaw.