Abstract: Plant cells are transformed by bringing them into contact with a a multiplicity of needle-like bodies on which the cells may be impaled. This causes a rupture in the cell wall allowing entry of transforming DNA either from a surrounding liquid medium or of DNA previously bound to or otherwise entrapped in the needle-like projections.

Abstract: A multi-jet print head for a continuous ink jet printer has its individual ink jets formed electrostatically instead of using a row of individual nozzles. Ink is supplied continuously through a slot in an electrically conducting body or to an elongated edge portion of such a body, while a strong electrostatic field is applied to draw off the ink as an array of parallel cusps. These break up at their tips to form a stream of ink drops which can then be deflected in known manner. The electrostatic field preferably has a reinforcing secondary field superimposed on it, which is cyclically varied at a suitable ink drop production frequency to synchronize formation of the ink drops at each of the cusp tips. This enables means for deflecting the drops to be synchronized with the moving drops for consistent deflections and corresponding optimum resolution.

Abstract: A process and apparatus for spraying liquid at a target, which comprises atomizing liquid by charging it electrostatically, projecting the charge atomized liquid on a path toward the target and at least partially discharging the charged particles so formed with an ionic discharge induced by the particles as they pass an earthed electrode having a sharp or pointed edge sited adjacent said path.

Abstract: An electrostatic spraying apparatus for spraying liquid has a spraying edge 8 provided with teeth 12. No parts of the apparatus provide a low potential influence near the spraying edge, keeping leakage losses to a minimum. At the voltage provided by a high voltage supply, the field strength at the tips of the teeth 12, is sufficient to form one ligament of liquid per tooth. The ligaments break up into droplets which have a size largely independent of fluctuations in field strength caused by varying the distance from the target to be sprayed.

Abstract: An apparatus for spraying liquids from a vehicle, suitably an aircraft or other airborne vehicle. The apparatus includes at least two sprayheads, each having adjacent thereto an associated electrode or an associated electrically conducting or semiconducting part of the vehicle. A generator applies potentials to the sprayheads and to the electrodes or conducting or semiconducting parts of the vehicle so that an intense electrical field is developed between the liquid which emerges from each sprayhead and the adjacent electrode or part. The intensity of each field is sufficient to atomise the emerging liquid. The polarities of the applied potentials are such that liquid emerging from one sprayhead is charged positively while liquid emerging from the other sprayhead is charged negatively.

Abstract: An apparatus for the electrostatic spraying of liquids, especially aqueous liquids, includes a sprayhead chargeable to a high electrical potential and at least one electrode having a sharp edge or point. The electrode is so arranged and is maintained at such a potential that the generally radially directed electrical forces acting upon the surface of a liquid emerging from the sprayhead are reduced. The liquid then assumes a ligamentary form prior to atomization.

Abstract: An electrostatic pump or pumping liquids having a resistivity in the range of 10.sup.10 to 10.sup.7 ohm cm has a pump housing. The pump housing includes a passageway through which the liquid is pumped, and a single injection electrode disposed upstream of the passageway. The electrode has a sharp electrically-conducting tip. A constriction in the region of the tip is shaped to conform to the surface configuration of the tip so that the liquid flows pass the tip in a laminar nonturbulent fashion through an orifice of reduced cross-section. The constriction is so dimensioned as to provide a high resistance path. A chamber is disposed downstream of the constriction and is of larger cross-section than the constriction. A discharged electrode is disposed in the chamber and is separated from the injection electrode by the chamber and the constriction. The injection and discharge electrodes are coupled to a high voltage generator to maintain an electric potential between the electrodes on the order of kilovolts.

Abstract: A valve comprises a port for the passage of fluid, a plug for interrupting the flow of fluid through the port mechanically biased into a closed position, and means for creating an electrostatic field for causing the plug to move relative to the port so as to open the valve.

Abstract: A container having attached to it at least one memory device carrying information relating to the intended contents of the container; the device being operably connectable to apparatus responsive to information communicated from the memory device whereby an operation actively involving the contents of the container may be performed in a manner at least partly determined by the characteristics of the contents.

Abstract: A modular fluid spraying system including: at least one container for the fluid or fluids to be sprayed the container being fluid plug connectable to at least one fluid pumping which is in turn fluid plug connectable to at least one boom section, the boom section carrying fluid supply connections and being fluid plug connectable to other boom sections and to at least one sprayhead assembly detachably securable to the said boom section or sections; and at least one electronic data processing circuit electrically plug-connectable to the system and pre-set so as to regulate at least one electrically responsive operating parameter of the system when the system is connected to a source of electrical power in use; whereby various numbers of containers and/or various numbers of boom sections may be added or subtracted to the system to achieve a desired combination of fluid delivery and spray area.

Abstract: Electrostatic spraying for pesticides comprises an electrically conducting or semi-conducting surface; means for supplying liquid adjacent the surface; and a field intensifying member in close proximity to the surface. A process for the ultra-low volume application of concentrated pesticidal formulations by means of the apparatus is also described.

Abstract: A hand-held electrostatic sprayer for use in a process for the electrostatic spraying of pesticides by producing a descending cloud of charged pesticide particles and impressing a lateral component of motion upon the cloud with the aid of a laterally disposed electrode charged in the same sense as the cloud, the sprayer including an elongated body forming the sprayer handle and having: a neck supporting a downwardly-directed electrostatic sprayhead; a reservoir for supplying liquid to the sprayhead; and a high voltage generator for charging the sprayhead to a high potential, wherein the neck carries one or more conductive elements extending downwardly from the neck beyond the sprayhead for impressing a lateral component of motion upon a cloud of charged liquid particles from the sprayhead, the elements being electrically connected to high potential of the same sign as the sprayhead.

Abstract: An agricultural chemical sprayer is disclosed using special pre-coded machine-readable chemical containers which, when attached for use, become an integral part of an automatic spray control system. The pre-coded data derived from a given container effectively prevents unauthorized and unsafe container refilling operations and, at the same time, automatically provides optimum control over the spray application rate (pump operation and/or electrostatic voltage), prevents mixing of incompatible spray solutions, prescribes proper spray system flushing procedures, and at all times after filling maintains an irreversible account of the available liquid remaining in the container. Provisions are made for monitoring the condition and/or operation of each spray nozzle and special connectors are provided for effecting optimum liquid and electrical circuit connections in such a system.

Abstract: A container for the electrostatic spraying of liquids, especially pesticides, having an integral conductive spray nozzle formed from two concentric tubes in which axial ribs and grooves between the tubes provide a liquid pathway to the nozzle mouth. Air is bled into the container in use through an extended pathway provided by a helical thread on the surface of a bung in the upper end of the inner tube.

Abstract: A liquid container adapted to form part of an electrostatic spraying apparatus and having attached to it a high voltage generator to supply the voltage required for the electrostatic spraying. The container and apparatus also include the electrical contacts necessary to connect the generator to an electrical power supply and to the electrostatic spraying apparatus.

Abstract: A holder for receiving a container which contains a liquid suitable for electrostatic spraying and which has a spray orifice comprises a body having a high voltage generator; a power source therefor; a field-intensifying electrode; electrical connections for connecting the electrode to an output terminal of the high voltage generator and for connecting the output terminal and the field-intensifying electrode to earth; a mounting device complementary to a mounting device on the container for locating the container on the holder with the spray orifice adjacent the electrode, the complementary mounting device having an electrical contact complementary to one on the container; and electrical connections for connecting the contact to the other output terminal of the high voltage generator.

Abstract: Spraying apparatus for spraying liquid pesticides on to crops growing in the ground includes a plurality of electrostatic spraying devices mounted on a boom which can be mounted on a powered vehicle such as a tractor or an aircraft. Each spraying device includes a spray-head having an at least electrically semi-conducting surface charged to a potential of the order of 1-20 kilovolts, a field intensifying electrode mounted adjacent the spray-head surface and being so sited relative to the spray-head surface that the electrostatic field thereat causes pesticide liquid delivered thereto to atomize without substantial corona discharge to form electrically charged particles.

Abstract: A system for the electrostatic spraying of liquids, particularly suitable for the application of pesticides at low volume. A sealable demountable container and support are provided, liquid being supplied from the container for atomization to an electrically conductive nozzle charged from one output terminal of a high voltage generator. Another output terminal of the high voltage generator connects to a field-intensifying electrode adjacent the nozzle, the electric circuit in the holder being completed by connections in the container. The nozzle and electrical power source preferably are carried on the container.

Abstract: A device to use as an agricultural sprayer, comprising a rotatable conductive sprayhead in the form of a disc or cup, means for supplying spray liquid from a reservoir to an inner surface of the sprayhead, an electric motor for rotating the sprayhead about its axis at a rate of 1000 to 8000 rpm, a circular induction electrode disposed adjacent the sprayhead rim, a high voltage generator for charging the electrode to a pontential in the range 1 to 3 Kilovolts, and means for earthing the sprayhead.

Abstract: An electrostatically sprayable insecticidal formulation comprising a solution of from 0.5 to 50% of permethrin or like compound in an organic solvent medium, the medium being formulated so that the formulation has a resistivity at 20.degree. C. in the range 1.times.10.sup.6 to 1.times.10.sup.10 ohm centimeter and a viscosity at 20.degree. C. of 5 to 50 centistokes.