1. A coaxial cable, comprising:
a metallic inner conductor formed of a first material and having a first thickness;
a dielectric layer circumferentially surrounding the inner conductor formed of a second material and having a second thickness;
a metallic outer conductor circumferentially surrounding the dielectric layer formed of a third material and having a third thickness; and
a polymeric jacket circumferentially surrounding the outer conductor formed of a fourth material and having a fourth thickness;
wherein at least one of the first material, first thickness, second material, second thickness, third material, third thickness, fourth material and fourth thickness is selected so that the cable has:
(a) a usable bandwidth between about 5 MHz and the cut-off frequency of the cable;
(b) a minimum bend radius of less than about 5 times the jacket outer diameter; and
(c) a velocity of propagation of greater than about 88;
(d) a return loss of at least about \u221225 dB; and
(e) a nominal impedance of 75 ohms.
2. The coaxial cable defined in claim 1, wherein at least one of the first material, first thickness, second material, second thickness, third material, third thickness, fourth material and fourth thickness is further selected so that the cable has a continuous usable bandwidth above about 1.0 GHz.
3. The coaxial cable defined in claim 1, wherein at least one of the first material, first thickness, second material, second thickness, third material, third thickness, fourth material and fourth thickness is further selected so that the cable has a continuous bandwidth above about 3.0 GHz.
4. The coaxial cable defined in claim 1, wherein at least one of the first material, first thickness, second material, second thickness, third material, third thickness, fourth material and fourth thickness is further selected so that the cable has an attenuation spike due to return loss within the usable bandwidth.
5. The coaxial cable defined in claim 1, wherein the cable has a length of at least 1,000 feet.
6. The coaxial cable defined in claim 1, wherein the first material is selected from the group consisting of: copper; aluminum and steel clad with copper; and aluminum, copper and steel clad with silver.
7. The coaxial cable defined in claim 1, wherein the second material is a foamed polymeric material.
8. The coaxial cable defined in claim 1, wherein the dielectric layer has a density gradient across its cross-section such that density increases with increasing radial distance from the inner conductor.
9. The coaxial cable defined in claim 1, wherein the third material is selected from the group consisting of solid copper and solid aluminum.
10. The coaxial cable defined in claim 1, wherein a corrosion-resistant material is interposed between the outer conductor and the jacket.
11. The coaxial cable defined in claim 10, wherein the corrosion-resistant material is a dry material.
12. The coaxial cable defined in claim 1, wherein the cable withstands at least 5 cycles in reverse bend fatigue tests.
13. A hybrid fiber cable (HFC) network, comprising:
two coaxial cables as defined in claim 1; and
an optical fiber in communication with the coaxial cable, wherein together the coaxial cable and the optical fiber define a transmission path.
14. The HFC network defined in claim 13, wherein the optical fiber has a zero dispersion wavelength of about 1310 nm, a loss at 1385 nm that is less than its loss at 1310 nm and a chromatic dispersion of between 1.5 and 8.0 psnm-km in the 1.4 \u03bcm wavelength region.
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 process for making an olefin product from an oxygenate-containing feedstock comprising:
a) contacting the feedstock in a reaction zone with catalyst particles comprising a molecular sieve containing an average density of acid sites of about 0.000325 mole per gram of said molecular sieve and having an average amount of carbon on said molecular sieve ranging from about 9.9 wt.% to about 12.9 wt.% based on the weight of the molecular sieve, wherein said average density of acid sites is is determined by NMR, under conditions effective to convert the feedstock into an olefin product stream and to provide unregenerated catalyst particles,
b) removing a portion of said unregenerated catalyst particles from said reaction zone and contacting said portion with a regeneration medium in a regeneration zone under conditions effective to obtain regenerated catalyst particles wherein said average amount of carbon on said molecular sieve of said regenerated catalyst particles is no greater than 9.9 wt.% based on the weight of said molecular sieve, and
c) introducing said regenerated catalyst particles into said reaction zone.
2. The process of claim 1 which further comprises
d) repeating steps a)\u2013c).
3. The process of claim 1 which is carried out in a circulating fluid bed reactor.
4. The process of claim 1 which is carried out in a circulating fluid bed reactor with continuous regeneration.
5. The process of claim 1 wherein said regenerated catalyst particles have an average coke level of at least 3.94 wt.% based on the weight of the unregenerated catalyst particles.
6. The process of claim 3 wherein said circulating fluid bed reactor is operated at at least 0.2 msec superficial gas velocity.
7. The process of claim 6 wherein said contacting is carried out in a riser.
8. The process of claim 3 wherein said circulating fluid bed reactor is operated at a feedstock conversion between 50% and 99%.
9. The process of claim 3 wherein said circulating fluid bed reactor is operated at a feedstock conversion between 75% and 95%.
10. The process of claim 1 wherein at least a portion of said catalyst mixture exits said reaction zone and is returned to said reaction zone without regeneration.
11. The process of claim 1 wherein said molecular sieve has a pore diameter of less than 5.0 Angstroms.
12. The process of claim 11 wherein said molecular sieve framework-type is selected from the group consisting of AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, and substituted groups thereof.
13. The process of claim 12 wherein said molecular sieve is selected from the group consisting of ALPO-18, ALPO-34, SAPO-17, SAPO-18, and SAPO-34.
14. The process of claim 12 wherein said molecular sieve is SAPO-34.
15. The process of claim 1, wherein said molecular sieve has a pore diameter of 5\u201310 Angstroms.
16. The process of claim 15 wherein said molecular sieve framework-type is selected from the group consisting of MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, and substituted groups thereof.