A system for managing table tennis balls facilitates retrieval of stray balls, stores them and dispenses them conveniently to a player as required. The system has two main components: a ball retriever, a.k.a. the BallSnatcher, and a storage rack, a.k.a. the BallFeeder. The tubular retriever can hold a column of balls and is deployed in a hand-held manner in a vertical orientation from a standing position. The retriever is fitted at its bottom end with a ball trap including (a) a flexible coaxial constriction ring defining an expandable entry opening that when lowered over a stray ball captures and retains it in the retriever tube, and (b) a flexible coaxial guidance flange extending outwardly and downwardly to provide initial guidance in retrieving a stray ball. The tubular storage rack is mounted below the playing surface of a game table at a low angle; an open upper end is located along one side of the table where it can receive balls in an easy transfer from the retriever, while the opposite lower end is fitted with an endstop/dispenser, located at an end of the table convenient to a player, that retains the balls in the rack and dispenses them one at a time as required for play. The storage tube is sized to receive the open top end of the retriever for ball transfer; furthermore, the retriever can inserted telescopically into the storage tube and left conveniently stored in this manner, ready to be easily pulled out for deployment.
The present invention provides a method of producing a transformed banana plant (genus,Musa), in particular by tranforming embroygenic material, or the somatic embryos derived from a banana plant, through incubation with Agrobacterium cells carrying exogenous DNA sequence(s), and obtaining regenerated plants.
A linear gain controlled amplifier comprising a differential transistor pair having an input and an output. The input is connected to a current supply which includes both AC and DC components. A voltage is derived which is proportional to the DC current component and this is compared with a control signal to produce an error signal which is supplied to the gain control terminals of the differential transistor pair. Traditionally, gain control has been implemented using a closed loop consisting of a power detector, a loop filter and a gain control element. The output of the power detector is compared with a reference voltage in a comparator, the output of which is filtered by the loop filter and applied to a control input of the gain control element. Most power detectors are either inaccurate or expensive and elaborate and may exhibit a control error of several decibels. The gain control elements themselves typically have non-linear control characteristics and suffer from poor repeatability and temperature variations which can necessitate extensive calibration. The present invention substantially avoids the foregoing problems by avoiding use of the prior art power detector and gain control element.
A quadrature downconversion stage in a radio frequency receiver compensates for leakage from the quadrature local oscillator to the input of the stage by deriving first and second feedback signals from the quadrature local oscillator. The first feedback signal is 180.degree. out of phase with the in-phase component of the signal supplied to the input of the stage and the second feedback signal is 180.degree. out of phase with the quadrature component of the signal supplied to the input of the stage. The invention reduces or cancels a d.c. offset that can appear at the output of the stage. Another advantage is the reduction of re-radiated signals resulting from the local oscillator leakage. The invention is particularly applicable to direct converters.
The invention relates to a dispenser for an oral hygiene composition which composition contains an effective anti-plaque proportion of triclosan and/or a flavour component wherein the dispenser and/or the dispenser parts that contact the composition include a polymeric material that is compatible with and does not cause excessive losses of triclosan and/or flavour from the oral hygiene composition.
A process for the removal of (cyclo)aliphatic hexene and hexadiene isomers from allyl chloride, characterized by a chlorination step which is performed in the liquid phase.
A double mode surface wave resonator comprises two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT. One or each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator. The electrodes of the IDTs can be arranged in spatial synchronism with adjacent fingers of the reflection gratings to reduce spurious longitudinal modes.