What is claimed is:
1. A repeater system comprising:
a transmitter for amplifying data received from an external base station transceiver system, converting the amplified data to a service frequency, and wirelessly sending the service frequency to a mobile station in a corresponding service area;
a receiver for amplifying the signal received from the mobile station and outputting the amplified signal to the base station transceiver system; and and
a controller for detecting the power level of the receiver, and preventing the output signal of the receiver from being sent to the base station transceiver system when the power level is above a first reference value during a first time or below a second reference value during a second time.
2. The repeater system as claimed in claim 1, wherein the controller comprises:
a high level detector, coupled to the output of the receiver, for detecting a high power level of the receiver;
a low level detector, coupled to the output of the receiver, for detecting a low power level of the receiver;
an integrated circuit for generating a control signal to preventing the output of the receiver from being sent to the base station transceiver system when the power level detected by the high level detector is above the first reference value during the first time, or when the power level detected by the low level detector is below the second reference value during the second time; and
a switch for enabling or disabling transmission of the output signal of the receiver to the base station transceiver system based on the control signal of the integrated circuit.
3. The repeater system as claimed in claim 1, wherein the transmitter comprises:
a first mixer for modulating a high frequency signal received from the base station transceiver system into an intermediate frequency signal;
a first surface acoustic wave (SAW) filter for filtering the output signal of the first mixer and outputting a desired intermediate frequency signal;
a second mixer for modulating the output signal of the first SAW filter into a high frequency signal; and
a first power amplifier for amplifying the output signal of the second mixer and outputting the amplified signal to the mobile station.
4. The repeater system as claimed in claim 1, wherein the receiver comprises:
a low-noise amplifier for amplifying a high frequency signal received from the mobile station;
a third mixer for modulating the output signal of the low-noise amplifier into an intermediate frequency signal;
a second SAW filter for filtering the output signal of the third mixer and outputting a desired high frequency signal;
a fourth mixer for modulating the output signal of the second SAW filter into a high frequency signal; and
a second power amplifier for amplifying the output signal of the fourth mixer and outputting an amplified signal.
5. A method for controlling a repeater system, comprising the steps of:
discriminating an oscillation signal of the repeater system, a talking signal and an access signal, disabling a reverse output of the repeater system during oscillation of the repeater system, and after an elapse of a first time, detecting the state of power of the reverse output;
disabling the reverse output of the repeater system when the power is in an oscillation state; and
enabling the reverse output of the repeater system when the power is not in the oscillation state and the reverse output is an access or talking signal.
6. The method as claimed in claim 5, further comprising the steps of:
determining whether the power has a minimum value when no subscriber exists during a predetermined time;
disabling the reverse output of the repeater system when the power maintains the minimum value; and
maintaining the reverse output of the repeater system using the access signal of the subscriber when the subscriber attempts to connect while the reverse output of the repeater system is disabled.
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 of modifying a chewing gum residue so as to ease removal of the chewing gum residue from a substrate, the method comprising applying to the residue a chewing gum modifying composition comprising an ionic liquid having the formula:
Cat+X\u2212
wherein: Cat+ is a cationic species, and
X\u2212 is an anionic species.
2. A method according to claim 1, wherein Cat+ is a cationic species selected from the group consisting of: ammonium, azaannulenium, azathiazolium, benzofuranium, borolium, diazabicyclodecenium, diazabicyclononenium, diazabicycloundecenium, dithiazolium, furanium, imidazolium, indolinium, indolium, morpholinium, oxaborolium, oxaphospholium, oxazinium, oxazolium, iso-oxazolium, oxathiazolium, pentazolium, phospholium, phosphonium, phthalazinium, piperazinium, piperidinium, pyranium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolium, quinazolinium, quinolinium, iso-quinolinium, quinoxalinium, selenazolium, tetrazolium, iso-thiadiazolium, thiazinium, thiazolium, thiophenium, triazadecenium, triazolium, and iso-triazolium.
3. A method according to claim 2, wherein Cat+ is a cationic species selected from the group consisting of:
N(Ra)(Rb)(Rc)(Rd)+ and P(Ra)(Rb)(Rc)(Rd)+
wherein Ra, Rb, Rc, and Rd are each independently selected from a C1 to C15, straight chain or branched alkyl group, a C1 to C15, a C3 to C8 cycloalkyl group, or a C6 to C10 aryl group, wherein said alkyl, cycloalkyl or aryl groups are unsubstituted or may be substituted by one to three groups selected from: C1 to C6 alkoxy, C2 to C12 alkoxyalkoxy, C6 to C10 aryl, C2 to C15 straight chain or branched alkenyl, \u2014CN, \u2014OH, \u2014NO2, \u2014CO2(C1 to C6)alkyl, \u2014OC(O)(C1 to C6)alkyl, C7 to C30 aralkyl and C7 to C30 alkaryl, and wherein Rb may also be hydrogen.
4. (canceled)
5. A method according to claim 3, wherein Cat+ is a cationic species selected from the group consisting of:
6.-7. (canceled)
8. A method according to claim 2, wherein Cat+ is a cationic species selected from the group consisting of:
wherein: Ra, Rb, Rc, Rd, Re, Rf, Rg and Rh are each independently selected from hydrogen, a C1 to C20 straight chain or branched alkyl group, a C3 to C8 cycloalkyl group, or a C6 to C10 aryl group, or any two of Rb, Rc, Rd, Re and Rf attached to adjacent carbon atoms may form a methylene chain \u2014(CH2)q\u2014 wherein q is from 3 to 6, and wherein said alkyl, cycloalkyl or aryl groups, or said methylene chain, are unsubstituted or may be substituted by one to three groups selected from: C1 to C6 alkoxy, C2 to C12 alkoxyalkoxy, C6 to C10 aryl, C2 to C15 straight chain or branched alkenyl, \u2014CN, \u2014OH, \u2014NO2, C7 to C10 aralkyl and C7 to C10 alkaryl, \u2014CO2(C1 to C6)alkyl, \u2014CO(O)(C1 to C6)alkyl.
9. A method according to claim 8, wherein Cat+ is a cationic species selected from the group consisting of:
10.-15. (canceled)
16. A method according to claim 1, wherein X\u2212 is an anionic species selected from the group consisting of: F\u2212, Cl\u2212, Br\u2212, I\u2212, NO3\u2212, NO2\u2212, BF4\u2212, PF6\u2212, SbF6\u2212, SCN\u2212, H2PO4\u2212, HPO42\u2212, PO43\u2212, HSO4\u2212, SO42\u2212, CH3SO3\u2212, C2H5SO3\u2212, C8H17SO3\u2212, CH3(C6H4)SO3\u2212, docusate\u2212, CH3OSO3\u2212, C2H5OSO3\u2212, C8H17OSO3\u2212, H3C(OCH2CH2)nOSO3\u2212 wherein n is an integer from 1 to 10, CF3CO2\u2212, (CF3SO2)3C\u2212, (CF3SO2)2N\u2212, CF3SO3\u2212, (CF3)2N\u2212, (C2F5)3PF3\u2212, (C3F7)3PF3\u2212, (C2F5)2P(O)O\u2212, (CH3)2PO4\u2212, (CH3)2P(O)O\u2212, {(CH3)3CCH2CH(CH3)CH2}2P(O)O\u2212, HCO2\u2212, CH3CO2\u2212, CH3CH2CO2\u2212, CH2(OH)CO2\u2212, CH3CH(OH)CO2\u2212, HCO3\u2212, CO32\u2212, CH3OCO2\u2212, C2H5OCO2\u2212, saccharin\u2212, and linoleate\u2212.
17.-21. (canceled)
22. A method according to claim 1, wherein the ionic liquid has a melting point below 100\xb0 C.
23. (canceled)
24. A method according to claim 1, wherein the chewing gum modifying composition further comprises one or more oxidizing reagents.
25. A method according to claim 24, wherein the oxidising reagents comprise an oxidation catalyst and an oxygen source.
26. A method according to claim 25, wherein the oxidation catalyst is a lanthanide salt or a transition metal salt.
27.-29. (canceled)
30. A method according to claim 25, wherein the oxygen source is selected from hydrogen peroxide, a hydrogen peroxide releasing compound, a salt having a halogen oxyanion, an organic hydroperoxide, an organic peroxyacid, or an organic peroxyacid salt.
31.-32. (canceled)
33. A method according to claim 1, wherein the chewing gum modifying composition further comprises:
(i) one or more natural or modified enzymes selected from the group consisting of laccases, peroxidases, ligninases and lipoxygenases; and
(ii) one or more enzyme mediator compounds.
34.-36. (canceled)
37. A method according to claim 33, wherein the one or more enzyme mediator compounds are selected from the group consisting of:
38.-41. (canceled)
42. A method according to claim 33, wherein the chewing gum modifying composition further comprises one or more enzymes selected from lipases and esterases.
43. A method according to claim 1, wherein the chewing gum modifying composition further comprises a co-solvent.
44. A method according to claim 43, wherein the co-solvent is water.
45. A method according to claim 43 wherein the ionic liquid and the co-solvent are present in the chewing gum modifying composition in a weight ratio of from 5:95 to 99:1.
46. (canceled)
47. A method according to claim 1, wherein the chewing gum modifying composition further comprises one or more additives selected from the group consisting of surfactants, viscosity modifiers, emulsifiers, melting point suppressants and wetting agents.
48. A method according to claim 1, wherein the chewing gum residue is derived from a chewing gum comprising between 10 and 75% by weight of a gum base, wherein the gum base comprises between 5 and 80% by weight of one or more elastomers.
49.-51. (canceled)
52. A method according to claim 1, wherein the substrate comprises stone, concrete, cement, bricks, gypsum, plasterboard, clay, ceramic, glass, asphalt, tarmac, bitumen, metals, wood, varnish, lacquer or a textile.
53. A method according to claim 1, where the modified residue is subsequently removed from the substrate by sweeping, scrubbing, vacuuming, or hosing with low pressure water.
54. A kit of parts for use in a method of removing chewing gum residues from substrates, the kit comprising:
(i) a first part comprising an ionic liquid as defined in claim 1;
(ii) a second part comprising an oxidation catalyst, the second part being optionally combined with the first part; and
(iii) an oxygen source as a third part.
55. A kit of parts for use in a method of removing chewing gum residues from substrates, the kit comprising:
(i) a first part comprising an ionic liquid as defined in claim 1;
(ii) a second part comprising one or more natural or modified enzymes selected from the group consisting of: laccases, peroxidases, lignases and lipoxygenases;
(iii) a third part comprising one or more enzyme mediator compounds, the third part being optionally combined with the first part or the second part.
56.-58. (canceled)
59. A composition comprising:
(i) an ionic liquid having the formula Cat+X\u2212, wherein Cat+ is a cationic species and X\u2212 is selected from the group consisting of: F\u2212, Cl\u2212, I\u2212, NO3\u2212, NO2\u2212, SbF6\u2212, SCN\u2212, H2PO4\u2212, HPO42\u2212, PO43\u2212, HSO4\u2212, SO42\u2212, CH3SO3\u2212, C2H5SO3\u2212, C8H17SO3\u2212, CH3(C6H4)SO3\u2212, docusate\u2212, C8H17OSO3\u2212, wherein n is an integer from 1 to 10, CF3CO2\u2212, (CF3SO2)3C\u2212, (CF3SO2)2N\u2212, CF3SO3\u2212, (CF3)2N\u2212, (C2F5)3PF3\u2212, (C3F7)3PF3\u2212, (C2F5)2P(O)O\u2212, (CH3)2PO4\u2212, (CH3)2P(O)O\u2212, {(CH3)3CCH2CH(CH3)CH2}2P(O)O\u2212, HCO2\u2212, CH3CO2\u2212, CH3CH2CO2\u2212, CH2(OH)CO2\u2212, CH3CH(OH)CO2\u2212, HCO3\u2212, CO32\u2212, CH3OCO2\u2212, C2H5OCO2\u2212, saccharin\u2212, and linoleate\u2212; and
(ii) one or more natural or modified enzymes selected from the group consisting of: laccases, peroxidases, lipoxygenases and ligninases.
60.-61. (canceled)
62. A composition according to claim 59, wherein the composition further comprises one or more enzyme mediator compounds selected from the group consisting of:
63. (canceled)
64. Use of an ionic liquid as defined in claim 1 for the removal of chewing gum residues from substrates.