1. A conductive element comprising a metal core and a coating, wherein the coating comprises at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof, and wherein the at least one layer has a predetermined thickness.
2. The conductive element according to claim 1, wherein the metal core comprises a metal that is selected from the group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof.
3. The conductive element according to claim 1, wherein the aluminide comprises an aluminide of at least one of chromium, titanium, niobium, zirconium, hafnium, iron, tin, yttrium, combinations thereof, and alloys thereof.
4. The conductive element according to claim 3, wherein the aluminide is a titanium aluminide.
5. The conductive element according to claim 3, wherein the aluminide is a niobium aluminide.
6. The conductive element according to claim 1, wherein the aluminide layer is formed from a layer of an aluminum coating on the metal core.
7. The conductive element according to claim 1, wherein the aluminide layer has been formed from a layer of an aluminum alloy coating on the metal core.
8. The conductive element according to claim 1, wherein the silicide comprises a silicide of at least one of aluminum, chromium, titanium, germanium, niobium, iron, hafnium, zirconium, combinations thereof, and alloys thereof.
9. The conductive element according to claim 8, wherein the silicide is niobium-chromium-titanium silicide.
10. The conductive element according to claim 8, wherein the silicide is niobium-chromium-titanium-iron silicide.
11. The conductive element according to claim 1, wherein the silicide layer has been formed from a layer of a silicon coating on the metal core.
12. The conductive element according to claim 1, wherein the silicide layer has been formed from a layer of a silicon alloy coating on the metal core.
13. The conductive element according to claim 1, wherein the predetermined thickness of the at least one layer is about 5 micrometers to about 500 micrometers.
14. The conductive element according to claim 13, wherein the predetermined thickness of the at least one layer is about 30 micrometers to about 300 micrometers.
15. The conductive element according to claim 14, wherein the predetermined thickness of the at least one layer is about 50 micrometers to about 150 micrometers.
16. A structure comprising:
a sealed envelope that is transparent or translucent;
at least two electrode tips disposed within the sealed envelope; and
at least two conductive feedthroughs, each of which is coupled to one of the at least two electrode tips, comprising a metal core and a coating, wherein the coating comprises at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof, and wherein the at least one layer has a predetermined thickness.
17. The structure according to claim 16, wherein the sealed envelope comprises a material selected from the group consisting of quartz, polycrystalline alumina, micro grain polycrystalline alumina, yttria, yttrium aluminum garnet, and ytterbium aluminum garnet.
18. The structure according to claim 16, wherein the at least two electrode tips comprises molybdenum.
19. The structure according to claim 16, wherein the at least two electrode tips comprises tungsten.
20. The structure according to claim 16 further comprising a dosing substance disposed within the sealed envelope.
21. The structure according to claim 20, wherein the dosing substance comprises a luminous gas.
22. The structure according to claim 16, wherein the metal core comprises a metal selected from the group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof
23. The structure according to claim 16, wherein the aluminide comprises an aluminide of at least one of chromium, titanium, niobium, zirconium, hafnium, iron, tin, yttrium, combinations thereof, and alloys thereof.
24. The structure according to claim 23, wherein the aluminide is a titanium aluminide.
25. The structure according to claim 23, wherein the aluminide is a niobium aluminide.
26. The structure according to claim 16, wherein the aluminide layer has been formed from a layer of an aluminum coating on the metal core.
27. The structure according to claim 16, wherein the aluminide layer has been formed from a layer of an aluminum alloy coating on the metal core.
28. The structure according to claim 16, wherein the silicide comprises a silicide of at least one of aluminum, chromium, titanium, germanium, niobium, iron, hafnium, zirconium, combinations thereof, and alloys thereof.
29. The structure according to claim 28, wherein the silicide is niobium-chromium-titanium silicide.
30. The structure according to claim 28, wherein the silicide is niobium-chromium-titanium-iron silicide.
31. The structure according to claim 16, wherein the silicide layer has been formed from a layer of a silicon coating on the metal core.
32. The structure according to claim 16, wherein the silicide layer has been formed from a layer of a silicon alloy coating on the metal core.
33. The structure according to claim 16, wherein the predetermined thickness of the at least one layer is about 5 micrometers to about 500 micrometers.
34. The structure according to claim 33, wherein the predetermined thickness of the at least one layer is about 30 micrometers to about 300 micrometers.
35. The structure according to claim 34, wherein the predetermined thickness of the at least one layer is about 50 micrometers to about 150 micrometers.
36. The structure according to claim 16, wherein the structure is a high intensity discharge lamp.
37. The structure according to claim 16, wherein the structure is a ceramic metal halide lamp.
38. The structure according to claim 16, wherein the structure is a high-pressure sodium lamp.
39. The structure according to claim 16, wherein the structure is an automotive lamp.
40. The structure according to claim 16, wherein the sealed envelope and the conductive feedthrough are exposed to air.
41. A method of making a conductive element, the method comprising:
providing a metal core;
providing a coating material comprising at least one of aluminum and silicon, and combinations thereof;
depositing the coating material on the metal core to form a coated metal core; and
heating the coated metal core to a predetermined temperature in an inert atmosphere to form at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof.
42. The method according to claim 41, wherein the coating material further comprises at least one of chromium, titanium, germanium, niobium, iron, tin, yttrium, and combinations thereof, and alloys thereof.
43. The method according to claim 41, wherein the metal core comprises a metal that from a group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof.
44. The method according to claim 41, wherein the depositing comprises a method selected from the group consisting of chemical vapor deposition, physical vapor deposition, slurry coating, spray coating, pack cementation, and combinations thereof.
45. The method according to claim 41, wherein the predetermined temperature is in a range from about 100\xb0 C. to about 1500\xb0 C.
46. The method according to claim 41, wherein the inert atmosphere comprises argon, helium, neon, krypton, xenon, and combinations thereof.
47. A method of making a conductive feedthrough for a lamp, the method comprising:
providing a niobium alloy core;
providing at least one precursor of a coating material in a slurry;
depositing the slurry on the niobium alloy core such that the niobium alloy core is covered by the slurry; and
heating the niobium alloy core covered by the slurry at a predetermined temperature in an inert atmosphere for a predetermined period of time to form a coating on the niobium alloy core.
48. The method according to claim 47, wherein the at least one precursor of a coating material comprises a metal elemental powder.
49. The method according to claim 47, wherein the metal elemental powder comprises at least one of aluminum, chromium, silicon, titanium, germanium, niobium, iron, tin, and yttrium.
50. The method according to claim 47, wherein the coating material comprises at least one alloy precursor.
51. The method according to claim 47, wherein the metal precursor comprises at least one of aluminum, chromium, silicon, titanium, germanium, niobium, iron, tin, and yttrium, combinations thereof, alloys thereof.
52. The method according to claim 47, wherein the slurry is formed by mixing the at least one precursor with a medium.
53. The method according to claim 52, wherein the medium comprises at least one of acid, alcohol, water, and combinations thereof.
54. The method according to claim 47, wherein the method further comprises adding a binder to the slurry.
55. The method according to claim 54, wherein the binder is magnesium oxide.
56. The method according to claim 47, wherein the depositing comprises immersing the metal core in the slurry for a time in a range from about 30 seconds to 1 hour.
57. The method according to claim 47, wherein the heating is carried out in a vacuum heating furnace.
58. The method according to claim 47, wherein the predetermined temperature is in a range from about 100\xb0 C. to about 1500\xb0 C.
59. The method according to claim 47, wherein the predetermined period of time is in a range from about 30 minutes to about 5 hours.
60. The method according to claim 59, wherein the predetermined period of time is in a range from about 1 hour to about 3 hours.
61. The method according to claim 47, wherein the inert atmosphere comprises argon, helium, neon, krypton, xenon, and combinations thereof.
62. An article of manufacture comprising the conductive element of claim 1.
63. The article of manufacture according to claim 62, wherein the article of manufacture is selected from a group consisting of lamps, electric motors, sensors, and thermocouples.
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 method for characterizing a retinal parameter as a function of polar angle \u03b8, the method comprising the steps of:
determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
calculating a first integral comprising an integral of the reference parameter function over the first interval;
calculating a second integral comprising an integral of the first measurement parameter function over the first interval; and
calculating a first characterization value based at least in part on the first integral and the second integral.
2. The method of claim 1, wherein the step of calculating a first characterization value comprises the step of:
calculating a first ratio comprising the ratio of the second integral to the first integral.
3. The method of claim 2, further comprising the step of:
diagnosing the health of an eye based at least in part on the first ratio.
4. The method of claim 2, further comprising the steps of:
comparing the first ratio to a threshold value; and
performing user-defined ophthalmological diagnostics if the first ratio is less than the threshold.
5. The method of claim 1, wherein:
the step of calculating a first integral comprises the step of calculating:
A
L
=
\u222b
\u03b8
1
\u03b8
2
\u2062
L
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein \u03b81 is the first polar angle, \u03b82 is the second polar angle, and L(\u03b8) is the reference parameter function; and
the step of calculating a second integral comprises the step of calculating:
A
M
=
\u222b
\u03b8
1
\u03b8
2
\u2062
M
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein M(\u03b8) is the first measurement parameter function.
6. The method of claim 5, further comprising the step of:
calculating a first ratio D=AMAL.
7. The method of claim 1, wherein the retinal parameter comprises a retinal thickness.
8. The method of claim 1, wherein the first measurement parameter function is generated from a three-dimensional optical coherence tomography volume dataset.
9. The method of claim 1, wherein the reference parameter function represents a p-th percentile value of a reference population.
10. The method of claim 1, wherein the first measurement parameter function is generated from values of the retinal parameter at each measurement locus in a set of measurement loci along a circle.
11. The method of claim 1, wherein the first measurement parameter function is generated from values of the retinal parameter in a neighborhood about each measurement locus in a set of measurement loci along a circle.
12. The method of claim 1, wherein the first measurement parameter function is based at least in part on values of the retinal parameter at a first time.
13. The method of claim 12, further comprising the steps of:
receiving a second measurement parameter function based at least in part on values of the retinal parameter at a second time;
determining a second interval of polar angles bounded by a third polar angle and a fourth polar angle wherein, at each polar angle within the second interval, the value of the second measurement parameter function is less than the value of the reference parameter function;
calculating a third integral comprising an integral of the reference parameter function over the second interval;
calculating a fourth integral comprising an integral of the second measurement parameter function over the second interval; and
calculating a second characterization value based at least in part on the third integral and the fourth integral.
14. The method of claim 13, wherein the step of calculating a second characterization value comprises the step of:
calculating a second ratio comprising the ratio of the fourth integral to the third integral.
15. The method of claim 13, further comprising the step of:
diagnosing the health of an eye based at least in part on at least one of:
the first polar angle;
the second polar angle;
the third polar angle;
the fourth polar angle;
the first characterization value; and
the second characterization value.
16. An apparatus for characterizing a retinal parameter as a function of polar angle \u03b8, the apparatus comprising:
means for determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
means for calculating a first integral comprising an integral of the reference parameter function over the first interval;
means for calculating a second integral comprising an integral of the first measurement parameter function over the first interval; and
means for calculating a first characterization value based at least in part on the first integral and the second integral.
17. The apparatus of claim 16, wherein the means for calculating a first characterization value comprises:
means for calculating a first ratio comprising the ratio of the second integral to the first integral.
18. The apparatus of claim 16, wherein:
the means for calculating a first integral comprises means for calculating:
A
L
=
\u222b
\u03b8
1
\u03b8
2
\u2062
L
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein \u03b81 is the first polar angle, \u03b82 is the second polar angle, and L(\u03b8) is the reference parameter function; and
the means for calculating a second integral comprises means for calculating:
A
M
=
\u222b
\u03b8
1
\u03b8
2
\u2062
M
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein M(\u03b8) is the first measurement parameter function.
19. The apparatus of claim 18, wherein the means for calculating a first characterization value based at least in part on the first integral and the second integral comprises:
means for calculating a first ratio D=AMAL.
20. The apparatus of claim 16, further comprising:
means for generating the first measurement parameter function from values of the retinal parameter at each measurement locus in a set of measurement loci along a circle.
21. The apparatus of claim 16, further comprising:
means for generating the first measurement parameter function from values of the retinal parameter in a neighborhood about each measurement locus in a set of measurement loci along a circle.
22. The apparatus of claim 16, wherein the first measurement parameter function is based at least in part on values of the retinal parameter at a first time.
23. The apparatus of claim 22, further comprising:
means for receiving a second measurement parameter function based at least in part on values of the retinal parameter at a second time;
means for determining a second interval of polar angles bounded by a third polar angle and a fourth polar angle wherein, at each polar angle within the second interval, the value of the second measurement parameter function is less than the value of the reference parameter function;
means for calculating a third integral comprising an integral of the reference parameter function over the second interval;
means for calculating a fourth integral comprising an integral of the second measurement parameter function over the second interval; and
means for calculating a second characterization value based at least in part on the third integral and the fourth integral.
24. The apparatus of claim 23, wherein the means for calculating a second characterization value comprises:
means for calculating a second ratio comprising the ratio of the fourth integral to the third integral.
25. A non-transitory computer readable medium storing computer program instructions for characterizing a retinal parameter as a function of polar angle \u03b8, the computer program instructions defining the steps of:
determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
calculating a first integral comprising an integral of the reference parameter function over the first interval;
calculating a second integral comprising an integral of the first measurement parameter function over the first interval; and
calculating a first characterization value based at least in part on the first integral and the second integral.
26. The non-transitory computer readable medium of claim 25, wherein the computer program instructions for calculating a first characterization value comprise computer program instructions defining the step of:
calculating a first ratio comprising the ratio of the second integral to the first integral.
27. The non-transitory computer readable medium of claim 25, wherein:
the computer program instructions defining the step of calculating a first integral comprise computer program instructions defining the step of calculating:
A
L
=
\u222b
\u03b8
1
\u03b8
2
\u2062
L
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein \u03b81 is the first polar angle, \u03b82 is the second polar angle, and L(\u03b8) is the reference parameter function; and
the computer program instructions defining the step of calculating a second integral comprise computer program instructions defining the step of calculating:
A
M
=
\u222b
\u03b8
1
\u03b8
2
\u2062
M
\u2061
(
\u03b8
)
\u2062
\u2146
\u03b8
,
wherein M(\u03b8) is the first measurement parameter function.
28. The non-transitory computer readable medium of claim 27, wherein the computer program instructions for characterizing a retinal parameter as a function of polar angle \u03b8 further comprise computer program instructions defining the step of:
calculating a first ratio D=AMAL.
29. The non-transitory computer readable medium of claim 27, wherein the first measurement parameter function is based at least in part on values of the retinal parameter at a first time.
30. The non-transitory computer readable medium of claim 29, wherein the computer program instructions for characterizing a retinal parameter as a function of polar angle \u03b8 further comprise computer instructions defining the steps of:
receiving a second measurement parameter function based at least in part on values of the retinal parameter at a second time;
determining a second interval of polar angles bounded by a third polar angle and a fourth polar angle wherein, at each polar angle within the second interval, the value of the second measurement parameter function is less than the value of the reference parameter function;
calculating a third integral comprising an integral of the reference parameter function over the second interval;
calculating a fourth integral comprising an integral of the second measurement parameter function over the second interval; and
calculating a second characterization value based at least in part on the third integral and the fourth integral.
31. The non-transitory computer readable medium of claim 30, wherein the computer program instructions defining the step of calculating a second characterization value comprise computer program instructions defining the step of:
calculating a second ratio comprising the ratio of the fourth integral to the third integral.