1. A method for adjusting load at a device under test, the method comprising:
at a testing platform:
determining whether a current operations rate associated with a device under test (DUT) is near a target operations rate, wherein the current operations rate is associated with one or more simulated users being simulated by the testing platform; and
in response to determining that the current operations rate associated with the DUT is not near a target operations rate, adjusting the current operations rate by increasing or decreasing the number of simulated users interacting with the DUT.
2. The method of claim 1 wherein the current operations rate includes a connection establishment rate, a layer 7 transaction rate, a layer 7 byte exchange or throughput rate, or a combination of two or more rates.
3. The method of claim 1 wherein the current operations rate is associated with a number of operations per second (OPS).
4. The method of claim 1 wherein the target operations rate is a maximum operations rate obtainable for a current configuration.
5. The method of claim 1 wherein determining that the current operations rate associated with the DUT is near the target operations rate includes determining that the difference between is the current operations rate and the target operations rate is below a threshold value and determining that the current operations rate does not exceed the target operations rate.
6. The method of claim 1 wherein each of the one or more simulated users is associated with a virtual thread.
7. The method of claim 1 wherein the virtual thread includes a sequence of layer 7 protocol actions or commands.
8. The method of claim 1 wherein the one or more simulated users utilize one or more processors in the testing platform.
9. The method of claim 1 wherein the testing platform includes two or more processors, wherein two or more simulated users are distributed among the two or more processors, and wherein the current operations rate is based on a sum of operations rates associated with the two or more processors or a plurality of network interface cards (NICs).
10. The method of claim 1 wherein adjusting the current operations rate by increasing or decreasing the one or more simulated users interacting with the DUT includes multiplying by a predetermined value the current number of simulated users or dividing by the predetermined value the sum of the current number of simulated users and a previous number of simulated users.
11. The method of claim 1 wherein the DUT includes an evolved packet core (EPC) network node, a serving gateway, a packet data network gateway, a network node, a base transceiver station (BTS), a node B, an evolved Node B (eNode B), a WiMAX base station, a server load balancer, a firewall, or a deep packet inspection device.
12. A system for adjusting load at a device under test, the system comprising:
a testing platform:
a load adjustment controller comprising at least one processor and memory, the load adjustment controller configured to determine whether a current operations rate associated with a device under test (DUT) is near a target operations rate, wherein the current operations rate is associated with one or more simulated users being simulated by the testing platform, and in response to determining that the current operations rate associated with the DUT is not near a target operations rate, to adjust the current operations rate by increasing or decreasing the number of simulated users interacting with the DUT.
13. The system of claim 12 the current operations rate includes a connection establishment rate, a layer 7 transaction rate, a layer 7 byte exchange or throughput rate, or a combination of two or more rates.
14. The system of claim 12 wherein the current operations rate is associated with a number of operations per second (OPS).
15. The system of claim 12 wherein the target operations rate is a maximum operations rate obtainable for a current configuration.
16. The system of claim 12 wherein the load adjustment controller is configured to determine that the current operations rate associated with the DUT is near the target operations rate by determining that the difference between is the current operations rate and the target operations rate is below a threshold value and determining that the current operations rate does not exceed the target operations rate.
17. The system of claim 12 wherein each of the one or more simulated users is associated with a virtual thread.
18. The system of claim 12 wherein the virtual thread includes a sequence of layer 7 protocol actions or commands.
19. The system of claim 12 wherein the one or more simulated users utilize one or more processors in the testing platform.
20. The system of claim 12 wherein the testing platform includes two or more processors and wherein the testing platform is configured to distribute two or more simulated users among the two or more processors and wherein the load adjustment controller is configured to calculate the current number of simulated user by aggregating operations rates associated with the two or more processors.
21. The system of claim 12 wherein the load adjustment controller is configured to adjust the current operations rate by increasing or decreasing the one or more simulated users interacting with the DUT by multiplying by a predetermined value the current number of simulated users or dividing by the predetermined value the sum of the current number of simulated users and a previous number of simulated users.
22. The system of claim 12 wherein the DUT includes an evolved packet core (EPC) network node, a serving gateway, a packet data network gateway, a network node, a base transceiver station (BTS), a node B, an evolved Node B (eNode B), a WiMAX base station, a server load balancer, a firewall, or a deep packet inspection device.
23. A non-transitory computer readable medium comprising computer executable instructions embodied in a computer readable medium that when executed by a processor of a computer control the computer to perform steps comprising:
at a testing platform:
determining whether a current operations rate associated with a device under test (DUT) is near a target operations rate, wherein the current operations rate is associated with one or more simulated users being simulated by the testing platform; and
in response to determining that the current operations rate associated with the DUT is not near a target operations rate, adjusting the current operations rate by increasing or decreasing the number of simulated users interacting with the DUT.
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 seal for a valve for use in a pharmaceutical dispensing device, which seal is formed from an elastomeric composition comprising:
(a) an isobutylene polymer or co-polymer thereof;
(b) a cross-linking agent for the isobutylene polymer or co-polymer thereof, wherein the cross-linking agent is sulphur or a sulphur-donating compound, and wherein the cross-linking agent is free of peroxide curing agents; and
(c) an accelerator for the cross-linking agent, wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof.
2. A seal as claimed in claim 1, wherein the elastomeric composition comprises one or more of polyisobutylene, polybutene, butyl rubber, halogenated butyl rubber, including derivatives thereof.
3. A seal as claimed in claim 2, wherein the elastomeric composition comprises bromobutyl rubber andor chlorobutyl rubber, including derivatives thereof.
4. A seal as claimed in claim 1, wherein the elastomeric composition comprises a blend of an isobutylene polymer or co-polymer thereof and a chlorine-substituted diene polymer or co-polymer thereof.
5. A seal for a valve for use in a pharmaceutical dispensing device, which seal is formed from an elastomeric composition comprising:
(a) a chlorine-substituted diene polymer or co-polymer thereof;
(b) a cross-linking agent for the chlorine-substituted diene polymer or co-polymer thereof, wherein the cross-linking agent is sulphur or a sulphur-donating compound, and wherein the cross-linking agent is free of peroxide curing agents; and
(c) an accelerator for the cross-linking agent, wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof.
6. A seal as claimed in claim 5, wherein the elastomeric composition comprises a chlorine-substituted butadiene polymer.
7. A seal as claimed in claim 6, wherein the elastomeric composition comprises 2-chlorobuta-1,3-diene.
8. A seal as claimed in claim 1, wherein said polysulphide compound is derived from a substituted xanthic acid or derivative thereof.
9. A seal as claimed in claim 1, wherein the substituted group in said polysulphide compound is an isopropyl group.
10. A seal as claimed in claim 1, wherein said polysulphide compound is diisopropyl xanthogen polysulphide.
11. A seal as claimed in claim 1, wherein said polysulphide compound comprises three or more bridging sulphur atoms.
12. A seal as claimed in claim 1, wherein said polysulphide compound is substantially free from nitrogen, phosphorus and metallic elements.
13. A seal as claimed in claim 1, wherein the elastomeric composition comprises up to 3 wt. % of the accelerator based on the total weight of the accelerator and polymer in the composition.
14. A seal as claimed in claim 13, wherein the elastomeric composition comprises up to 1.5 wt. % of the accelerator based on the total weight of the accelerator and polymer in the composition.
15. A seal as claimed in claim 1, wherein the weight ratio of the accelerator to the cross-linking agent in the elastomeric composition is in the range of from 1:1 to 3:1.
16. A seal as claimed in claim 1, wherein the seal further includes a mineral filler.
17. A seal as claimed in claim 16, wherein the mineral filler is selected from one or more of magnesium silicate, aluminium silicate, silica, titanium oxide, zinc oxide, calcium carbonate, magnesium oxide magnesium carbonate, magnesium aluminium silicate, aluminium hydroxide, talc, kaolin, clay and amino silane coated clay.
18. A seal as claimed in claim 1, wherein the seal further includes a process aid, preferably a low molecular weight polyethylene.
19. A seal as claimed in claim 1, further comprising one or more of a reinforcement agent, a plasticizer, a binder, a stabilizer, a retarder, a bonding agents, an antioxidant, a lubricant, a pigment, a wax, a resin, an antiozonants, a secondary accelerator or an activator.
20. A valve for use in a pharmaceutical dispensing device having a seal as defined in claim 1.
21. A pharmaceutical dispensing device having a valve as claimed in claim 20.
22. A pharmaceutical dispensing device as claimed in claim 21 which is a pharmaceutical metered dose aerosol inhaler device.
23. A dispensing apparatus for dispensing pressurised fluid comprising a valve body defining a chamber, a valve member extending movably through the chamber and through at least one annular seal co operating with the valve member and the body to regulate the discharge of fluid, wherein the or at least one of the seals is as defined in claim 1.
24. A dispensing apparatus which comprises a pressurised dispensing container having a valve body provided with two annular valve seals through which a valve member is axially slidable, said seals being disposed at inlet and outlet apertures of a valve chamber so that the valve functions as a metering valve, wherein at least one of the annular valve seals is as defined in claim 1.
25. A dispensing apparatus as claimed in claim 23, comprising a pressurised dispensing container operatively connected to the valve body and containing the fluid to be dispensed and a hydrofluorocarbon propellant comprising propellant type 134a or 227.
26. A dispensing apparatus as claimed in clam 23, wherein the fluid to be dispensed comprises a liquid or particulate product as a solution or suspension in a carrier liquid comprising alcohol.
27. A dispensing apparatus as claimed in claim 26, wherein the alcohol comprises ethanol.
28. A seal as claimed in claim 1, which seal comprises a vulcanisate of an isobutylene polymer or co-polymer thereof, a cross-linking agent for the isobutylene polymer or co-polymer thereof, and an accelerator for the cross-linking agent, wherein the cross-linking agent is sulphur or a sulphur-donating compound and is free of peroxide curing agents, and wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof.
29. A seal as claimed in claim 5, which seal comprises a vulcanisate of a chlorine-substituted diene polymer or co-polymer thereof, a cross-linking agent for the chlorine-substituted diene polymer or co-polymer thereof, and an accelerator for the cross-linking agent, wherein the cross-linking agent is sulphur or a sulphur-donating compound and is free of peroxide curing agents, and wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof.
30. A process for the preparation of a seal for a valve for used in a pharmaceutical dispensing device, the process comprising:
(i) forming a composition comprising a mixture of an isobutylene polymer or co-polymer thereof, a cross-linking agent for the isobutylene polymer or co-polymer thereof, and an accelerator for the cross-linking agent, wherein the cross-linking agent is sulphur or a sulphur-donating compound and is free of peroxide curing agents, and wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof;
(ii) initiating a cross-linking reaction in the mixture to form a cross-linked elastomeric composition; and
(iii) either before or after (ii) forming the composition into a seal.
31. A process for the preparation of a seal for a valve for use in a pharmaceutical dispensing device, the process comprising:
(i) forming a composition comprising a mixture of a chlorine-substituted diene polymer or co-polymer thereof, a cross-linking agent for the chlorine-substituted diene polymer or co-polymer thereof, and an accelerator for the cross-linking agent, wherein the cross-linking agent is sulphur or a sulphur-donating compound and is free of peroxide curing agents, and wherein the accelerator is a polysulphide compound derived from a substituted dithiocarbonic acid or derivative thereof;
(ii) initiating a cross-linking reaction in the mixture to form a cross-linked elastomeric composition; and
(iii) either before or after (ii) forming the composition into a seal.
32. A process as claimed in claim 30 or claim 31, wherein the step of forming the composition into a seal involves one or more forming techniques selected from compression moulding, injection moulding and extrusion.
33. A process as claimed in claim 30, wherein the process also involves washing the seals.
34. A process as claimed in claim 30, wherein the seals are immersed in an aqueous chlorinated solution.
35. A process as claimed in claim 34, wherein the aqueous chlorinated solution comprises water and HOCl.
36. A process as claimed in claim 30, wherein the seals are immersed in a solution comprising water and sodium dichloroisocyanurate (NaDCC).