Abstract: A golf putting practice aid has a rectangular base frame that serves as a stroke window for shot set-up and aiming purposes. A side frame is movably mounted on the base frame for pivotal movement from a folded, minimum profile storage configuration to an upright operative putting position. The side frame includes an elongated guide bar disposed in parallel alignment with the longitudinal axis of the stroke window for engaging and guiding pendulum movement of a putter shaft during execution of a putting stroke. The slope angle of the side frame relative to the base frame, and thus the elevation of the guide bar, is manually adjustable to suit the golfer's personal swing preference and putter selection. The guide bar and one of the base rails are marked with colored bands for indicating back swing stroke range and follow-through stroke range.

Abstract: A navigation-satellite receiver network comprises a server connected to the Internet to provide real-time correction information to clients. The server includes a GPS receiver that provides for tracking of a constellation of navigation satellites. When a client is online, it can receive satellite position and velocity information in the form of a polynomial and coefficients. Clock, ionosphere, troposphere, and other corrections are all bundled into one polynomial. The client therefore never computes or uses almanac or ephemeris.

Abstract: A navigation-satellite receiver comprises means for initialization that gets a head start by knowing time to within a few seconds and position to within 150 kilometers. A two-dimensional grid of points is setup with constant altitude that represents solution starting points within the 150 kilometer area. Fractional pseudoranges from each satellite in a constellation are inspected for a best initial fit with the points in the grid. A variety of time bias adjustments within the time bounds are also tried against the points to find a best fitting point. That point then is used in a drive to find the final solution and to produce the first fix from cold start.

Abstract: A navigation-satellite receiver network comprises a server connected to the Internet to provide real-time correction information to clients. The server includes a GPS receiver that provides for tracking of a constellation of navigation satellites. When a client is online, it can receive satellite position and velocity information in the form of a polynomial and coefficients. Clock, ionosphere, troposphere, and other corrections are all bundled into one polynomial. The client therefore never computes or uses almanac or ephemeris.

Abstract: A navigation-satellite receiver comprises means for initialization that gets a head start by knowing time to within a few seconds and position to within 150 kilometers. A two-dimensional grid of points is setup with constant altitude that represents solution starting points within the 150 kilometer area. Fractional pseudoranges from each satellite in a constellation are inspected for a best initial fit with the points in the grid. A variety of time bias adjustments within the time bounds are also tried against the points to find a best fitting point. That point then is used in a drive to find the final solution and to produce the first fix from cold start.

Abstract: A method and apparatus are provided in which silver ions are removed from a photographic fixer solution in a simple and efficient manner. The electrical conductivity of the solution is measured, which is effectively that of the fixer (thiosulphate). The electrical potential of the solution is measured between two electrodes immersed therein. A predetermined algorithm is applied to the two values to determine the silver ion concentration. If this is above a predetermined level, a silver recovery unit is activated. The measurements allow this unit to operate more efficiently than hithertobefore.

Abstract: An electronic sampling circuit for determining redox potentials, and consequently specie concentration, in a photographic solution, applies a linear ramp of a square wave voltage to a first electrode (6) immersed in the solution. The current drawn by an adjacent electrode (12) is converted to a voltage for sampling. A pair of sample-and-hold circuits (40,42) store signals sampled at the peak and adjacent trough respectively of a square wave pulse, and a subsequent analogue difference circuit (44) subtracts the two signals. The resulting signal is converted to a digital code by a low cost, low bit count analogue-to-digital converter (46), which is stored on a microprocessor (48). The sampling process is repeated for successive square waves along the ramp. This circuit configuration enables the difference between analogue signals to be measured where the signals differ in amplitude by small amounts but have a wide dynamic range, without the need for an expensive, high bit count analogue-to-digital converter.

Abstract: A pH electrode arrangement comprises an inner wire electrode of silver sulfide, and a fill solution comprising a solution of sodium thiosulphate, a buffer, and an antioxidant. The arrangement has a fast response to a change in temperature, a half cell near .+-.500 mV, and an isopotential point near 7 pH.

Abstract: A liquid is separated into its constituent species by electrophoresis along a capillary channel. A plurality of the channels is provided in the thickness of an injection molded plastics disc. The disc is rotatably mounted such that samples are dispensed into successive channels. When all twelve channels have been used, the disc is replaced with a fresh one.

Abstract: The device (1) has a cell (3) with an electrode structure for carrying out electrochemical detection or measurement of a liquid sample. A means for mechanically or pneumatically drawing the liquid sample into the cavity (20) of the cell (3) is provided. The drawing means may be in the form of a strip (10) which is mechanically drawn through the cell (3) drawing the liquid sample into the cavity (20) of the cell (3). The strip (10) can have a V-shape (44) portion which is placed in the liquid sample before the strip (10) is drawn through the cell (3).

Abstract: A method of measuring the silver ion activity of a mixed halide solution or dispersion comprises measuring the potential difference between a silver halide coated silver electrode and a reference electrode immersed in the solution or dispersion. Prior to measuring the potential difference an electrical pulse is applied to the silver electrode which in a first phase electrochemically strips the electrode surface and in a second phase electrochemically coats the electrode with a silver halide having the halide ion ratio of the solution or dispersion.

Abstract: An electrochemical device for providing a visual indication of the remaining life of a battery, the device comprising an electrode pair with a layer therebetween, the layer comprising a mixture of a photographic color coupler dispersion, an antioxidant and a photographic color developer in a binder.

Abstract: A half-cell reference electrode comprises an electrode member in electrochemical contact with at least one gelled electrolyte solution which itself is contactable with the liquid to be tested wherein the gelling agent comprises a polymer containing acrylamide units substituted with a group or groups which lower the polymer's tendency to hydrolyse compared to polyacrylamide while providing a polymer that can form a gelled solution in 2.6M sodium/potassium nitrate solution (2.21M potassium nitrate and 0.39M sodium nitrate) comprising at least 75% (w/w) sodium/potassium nitrate solution.