1. A method of operating a portable electrical power source, the method comprising:
generating electrical energy in a fuel cell;
providing the fuel cell electrical energy to a load;
detecting a potential stoichiometric disturbance for the fuel cell;
in response to detecting the potential stoichiometric disturbance, electrically initiating a secondary electrical energy source to provide electrical energy to the load;
recording a flow rate of oxygen and a flow rate of hydrogen to the fuel cell;
in response to detecting the potential stoichiometric disturbance, electrically disconnecting the fuel cell from the load;
maintaining oxygen flow and hydrogen flow to the fuel cell while the secondary electrical energy source provides electrical energy to the load and while the fuel cell is electrically disconnected from the load; and
altering the flow rate of oxygen or the flow rate of hydrogen according to an electrical state of the load.
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 compound of formula I
wherein R1, R2, R3, R4, R7 and R8 are independently selected from hydrogen, C1-C4alkyl, C1-C2alkanol or hydroxyl;
A is SiR5R6OwSiR5R6, wherein R5 and R6 are independently selected from C1-4alkyl or phenyl, and v is from 1-20 and w is from 0 to 60;
m and n are integers independently selected from 1 to 10; p is 1; and q is an integer from 0 to 6; and
X and Y are independently selected from O or NR9, wherein R9 is hydrogen, C1-C4alkyl or C1-C2alkanol.
2. The compound of claim 1 wherein Y is NR9 and X is O.
3. The compound of claim 1 wherein Y is O and X is NR9.
4. The compound of claim 1 wherein Y is NR9 and X is NR9.
5. The compound of claim 1 wherein m and n are 2 or 3, and R1, R2, R3 and R4 are hydrogen.
6. The compound of claim 5 wherein q is 0, 1 or 2, Y is O and X is NR9.
7. A compound of formula II
wherein R1, R2, R3, R4, R7 and R8 are independently selected from hydrogen, C1-C4alkyl, C1-C2alkanol or hydroxyl;
A is SiR5R6OwSiR5R6, wherein R5 and R6 are independently selected from C1-4alkyl or phenyl, and w is from 0 to 60;
m and n are integers independently selected from 1 to 10; p is 1; and q is an integer from 0 to 6.
8. The compound of claim 7 wherein m and n are 2 or 3, p is 0, q is 0, 1 or 2 and R1, R2, R3 and R4 are hydrogen.
9. An ophthalmic lens comprising a hydrophilic monomer and a silicone-containing lens monomer, wherein at least one of the crosslink agents is of formula I
wherein R1, R2, R3, R4, R7 and R8 are independently selected from hydrogen, C1-C4alkyl, C1-C2alkanol or hydroxyl;
A is SiR5R6OwSiR5R6, wherein R5 and R6 are independently selected from C1-4alkyl or phenyl, and w is from 0 to 60;
m and n are integers independently selected from 1 to 10; p is 1; and q is an integer from 0 to 6; and
X and Y are independently selected from O or NR9, wherein R9 is hydrogen, C1-C4alkyl or C1-C2alkanol.
10. The ophthalmic lens of claim 9 wherein the hydrophilic monomer is selected from the group consisting of N-vinyl pyrrolidone, N-vinyl piperidone, N-vinyl-c-caprolactam, N-vinylimidazolidone, N-vinylsuccinimide, N-vinylforamide and mixtures thereof.
11. The ophthalmic lens of claim 9 wherein the hydrophilic monomer is N-vinyl pyrrolidone.
12. The ophthalmic lens claim 9 wherein the hydrophilic monomer has a has a reactivity ratio Rh=khhkhx and the crosslink agent of formula I has a reactivity ratio Rx=kxxkxh, wherein khh, khx, kxx and kxh are the propagation constants for the following radical polymerization reactions, and Mh represents the hydrophilic monomer, Mh* represents the hydrophilic monomer radical, Mx represents the crosslink agent of formula I, II or III, and Mx* represents the crosslink agent radical of formula I
Mh*+Mh\u2192MhMh*\u2003\u2003khh;
Mh*+Mx\u2192MhMx*\u2003\u2003khx;
Mx*+Mx\u2192MxMx*\u2003\u2003kxx;
Mx*+Mh\u2192MXMh*\u2003\u2003kxh; and the ratio RhRx is from 0.1 to 10,
the silicone containing lens monomer has a reactivity ratio Rl=kllkly and a second crosslink agent has a reactivity ratio Ry=kyykyl, wherein kll, kly, kyy and kyl are the propagation constants for the following radical polymerization reactions, and MI represents the silicone-containing lens monomer, Ml* represents the silicone-containing lens monomer radical, My represents the second crosslink agent, and My* represents the second crosslink agent radical,
Ml*+Ml\u2192MlMl*\u2003\u2003kll;
Ml*+My\u2192MlMy*\u2003\u2003kly;
My*+My\u2192MyMy*\u2003\u2003kyy;
My*+Ml\u2192MyMl*\u2003\u2003kyl; and the ratio RlRy is from 0.1 to 10, and
the hydrophilic monomer and the silicone containing lens monomer have a ratio, RHRL, greater than 10 or less than 0.1.