1. A wipe comprising a water-insoluble substrate and a cleaning composition, said cleaning composition comprising from 1% to 15% water, a sulphate-containing surfactant and a buffer.
2. A wipe according to the preceding claim wherein the cleaning composition comprises 2-12% water.
3. A wipe according to claim 1 wherein the sulphate-containing surfactant is selected from the group consisting of alkyl sulphate, alkyl alkoxy sulphate, alkyl ether sulphate and mixtures thereof.
4. A wipe according claim 1 wherein the sulphate-containing surfactant is present in an amount of 30% to 80% by weight of the cleaning composition.
5. A wipe according to claim 1 wherein the buffer is either organic or inorganic.
6. A wipe according to claim 1 wherein the buffer has a pKa of from 6 to 12.
7. A wipe according to claim 1 wherein the buffer comprises at least one selected from a basic group, a basic group in combination with an acidic group or a basic group in combination with a neutral group.
8. A wipe according to claim 1 wherein the wipe is dry or substantially dry to the touch.
9. A wipe according to claim 1 wherein the water-insoluble substrate comprises at least two outward facing surfaces, one of which is more abrasive than the other.
10. A wipe according to claim 1 wherein the water-insoluble substrate is a laminate of more than two substrate layers.
11. A wipe according to claim 1 wherein the water-insoluble substrate comprises a water impermeable film.
12. A wipe according to claim 1 wherein the cleaning composition is in the form of a paste.
13. A wipe according to claim 1 wherein the cleaning composition is coloured with a dye or pigment.
14. A wipe according to claim 1 wherein the cleaning composition is applied onto the wipe as strips of paste and wherein the strips may be the same or different colours.
15. A wipe comprising a water-insoluble substrate, a first and a second cleaning composition, the first composition being formulated according to claim 1, the second composition comprising from 15% to 25% water.
16. A method of using a wipe according to claim 1 or claim 15 wherein the wipe is contacted with water before being applied to a surface to be cleaned.
17. A process of drying a sulphate-containing surfactant comprising heating the surfactant in a thin film evaporator to a temperature of 70 to 200\xb0 C. in the presence of a buffer, for a residence time of 10 minutes.
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 tunable quadrature phase shifter, comprising:
an input means for inputting an input signal;
splitting means for splitting the input signal into two essentially orthogonal first and second signals;
adding means for adding said first and second signals;
subtracting means for subtracting said first and second signals;
a first output for outputting a first output signal based on the output signal from said adding means; and
a second output for outputting a second output signal based on the output signal from said subtracting means, wherein said splitting means is an all-pass having a time constant of Cgm, where C is a capacitance in the subtracting means and gm is the transconductance of the subtracting means.
2. The phase shifter of claim 1, further comprising a first output buffer means for buffering said first output signal, and a second output buffer means for buffering said second output signal.
3. The phase shifter of claim 1, further comprising a first transimpedance converter having its input connected to said input means.
4. The phase shifter of claim 1, further comprising a first transimpedance converter having its output connected to said first output, and a second transimpedance converter having its output connected to said second output.
5. The phase shifter of claim 3, wherein the transimpedance converter is a transimpedance amplifier.
6. The phase shifter of claim 2, wherein said first and second output buffer means are first and second transimpedance converters, respectively.
7. A data and clock recovery unit comprising a phase detector which includes a phase shifter having
an input means for inputting an input signal;
splitting means for splitting the input signal into two essentially orthogonal first and second signals;
adding means for adding said first and second signals;
subtracting means for subtracting said first and second signals;
a first output for outputting a first output signal based on the output signal from said adding means; and
a second output for outputting a second output signal based on the output signal from said subtracting means, wherein said splitting means is an all-pass having a time constant of Cgm, where C is a capacitance in the subtracting means and gm is the transconductance of the subtracting means.