Abstract: An example apparatus for charge neutralization includes: a first emitter nozzle; a power supply configured to supply a high frequency alternating current (AC) signal to the first emitter nozzle; control circuitry configured to: provide a polarity signal to the power supply to generate a DC offset signal, wherein a combination of the high frequency AC signal and the DC offset signal causes the power supply to output a positive ion generation pulse or a negative ion generation pulse; control the polarity signal to cause the power supply to provide a period of positive ion generation and a period of negative ion generation; determine a balance voltage at an output of the first emitter nozzle; and control the polarity signal to adjust a relative durations of the period of positive ion generation and the period of negative ion generation based on the balance voltage.

Abstract: A high-voltage power supply system (1) for powering an electrostatic precipitator, ESP (10) is disclosed. The system has an AC supply circuit (2) configured to generate a first and a second AC supply voltage, and two supply circuits (5, 6) connected between the AC supply circuit and the ESP. One of the supply circuits is a DC supply circuit (5) configured to transform and convert the first AC supply voltage to a DC base voltage for the ESP, while the other is a pulse supply circuit having a pulse forming circuit (12) configured to generate and forward high-voltage pulses to the ESP. The AC supply circuit is configured such that each of the AC supply voltages are in the mid frequency range, i.e. in the range of 100 Hz to 5000 Hz. Hereby, a cost effective, low weight and compact high-voltage power supply system is presented.

Abstract: A device for controlling current to a solid state lighting load includes a capacitor (241, 341) and a current source (245, 345). The capacitor is connected in a parallel arrangement with the solid state lighting load (260, 360). The current source is connected in series with the parallel arrangement of the capacitor and the solid state lighting load. The current source is configured to modulate dynamically an amplitude of an input current provided to the parallel arrangement of the capacitor and the solid state lighting load based on an input voltage.

Abstract: A circuit can be used for charging a capacitor with an AC voltage. In one embodiment, the circuit includes a capacitor coupled to be charged with the AC voltage. An adjustment is configured to adjust a capacitor charge speed according to a value of the AC voltage. The adjustment circuit includes at least one bipolar transistor coupled to receive a voltage at a base of the bipolar transistor. The voltage is a function of the value of the AC voltage.

Abstract: A device for decreasing soot particles in exhaust gas, especially from an internal combustion engine, includes concentric outer and inner tubes forming an intermediate space through which the exhaust gas can flow. At least one annular electrode with a multiplicity of electrode tips protruding radially into the intermediate space is disposed on the inside of the outer tube. Terminals can connect the annular electrode and inner tube to a high voltage source forming an electric field in the intermediate space. At least two electrodes are preferably disposed axially at an electrode spacing of preferably 10 to 30 mm. The electrode tips can be approximately conical or pin-shaped with a radial length of 3 to 10 mm. The electrode tips of each electrode have a tip spacing in circumferential direction of 3 to 20 mm or 5 to 10 mm creating a very effective and uniform radial electric field for ionization.

Abstract: An air purifier having an electret module for capturing airborne particles, the electret module including an electret element disposed within a housing and an adhesive layer coupled to the housing to capture airborne particles, whereby the static field of the electret attracts the airborne particles, which subsequently adhere to the adhesive layer.

Abstract: An apparatus for dissipating energy into the exhaust gas of an internal combustion engine includes a container for confining a flow path for exhaust gas from an internal combustion engine where the container has an inlet and an outlet. A porous, electrically conductive mesh is placed in the container such that exhaust gas can flow through the conductive mesh. At least two electrical terminals are in permanent electrical contact with the conductive mesh. An electrical power supply completes an electrical circuit through the conductive mesh with the power supply having two or more electrical outputs electrically connected to an equal number of electrical terminals on the conductive mesh. The apparatus provides a filter, heater, electrical load and silencer.

Abstract: An air purifier includes a housing, a high voltage power supply, a first electrode assembly in which a wire-like first electrode is either the only first electrode or, alternatively, is spaced sufficiently far from any other such first electrodes so as to avoid undesirable effects upon each other, and a second electrode assembly in which there are a plurality of blade-like second electrodes. The air purifier can be of the type in which air flows through the housing as a result of electro-kinetic effects. To increase air flow velocity, the voltage between first and second electrodes is relatively high, such as 23-50 kV, and the first and second electrodes are accordingly spaced apart a relatively great distance, such as at least 30 mm.

Abstract: An electrostatic precipitator including: a collecting electrode in a gas passage; a discharge electrode in the gas passage and separated by a gap from the collecting electrode; a power supply applying a voltage to the discharge electrode, wherein the voltage establishes an electric field between the discharge electrode and the collecting electrode to ionize gas flow in the gap, and a resistor in series with the discharge electrode and having an effective resistance in series with the discharge electrode of at least 50 Ohms.

Abstract: Provided are an air purifier and an air conditioner including the same. The air purifier includes a ground electrode part, a discharge electrode, at least a pair of magnetic force generators, and a voltage generator. The ground electrode part has at least a pair of flat plates. The discharge electrode is located between the flat plates and separated from the flat plates. The at least a pair of magnetic force generators is provided to the flat plates, respectively, to generate a magnetic field and allow attractive force to be applied between the flat plates. The voltage generator applies a voltage between the ground electrode part and the discharge electrode.

Abstract: The invention relates to a pulse generating system for generating high voltage pulses to energize an electrostatic precipitator (10), the system including: a first power supply (1) and a second power supply (2), where said second power supply (2) is arranged to pre-charge said electrostatic precipitator (10) to a DC voltage; a storage capacitor (7) and a series inductance; a switching device (5) coupled in parallel with an anti-parallel rectifier device (6); and wherein the system is arranged to be coupled to the electrostatic precipitator. The invention relates to provide such a pulse generating system with enhanced efficiency compared to present pulse generating systems and with enhanced protection of the components of the system in case of sparks in the electrostatic precipitator (10). This is achieved, when the switching device (5) of the system has turn-off capability and when the system includes a clamping circuit (11-13; 60-67).

Abstract: A system and method for ionization detection in electrically enhanced air filtration systems is described. One embodiment includes a system for electrically enhanced air filtration, the system comprising an electrically enhanced filter comprising a filter and an ionizing electrode disposed on an upstream side of the filter; a control device connected to the electrically enhanced filter, wherein the control device can control the electrically enhanced filter; and an ionization detector, wherein the ionization detector is adjacent to the electrically enhanced filter and wherein the ionization detector is connected to the control device.

Abstract: A gas separation apparatus using electrostatic precipitators and mechanical rappers is enhanced by the addition of an opposite polarity refreshing power supply and a switching arrangement. The switching components selectively disconnect the primary power supply and connect the refreshing power supply to the electrostatic precipitator, causing an electrical impulse in the precipitator sufficient to dislodge precipitate from the collector plates. In one embodiment, an RC filter is further provided to control the impulse and reduce the burden that would otherwise be placed upon the refreshing power supply. In a second embodiment, a pair of SCR strings serve as the switches. Cleaning power is delivered from a capacitor through one of the SCR strings using a resonant circuit, the resonance which causes the SCR string to commutate off after the impulse has been delivered.

Abstract: The invention relates to a pulse generating system for generating high voltage pulses to energize an electrostatic precipitator (10), said system comprising: a first power supply (1) and a second power supply (2), where said second power supply (2) is arranged to pre-charge said electrostatic precipitator (10) to a DC voltage; a storage capacitor (7) and a series inductance; a switching device (5) coupled in parallel with an anti-parallel rectifier device (6); and wherein said system is arranged to be coupled to said electrostatic precipitator. The invention relates to provide such a pulse generating system with enhanced efficiency compared to present pulse generating systems and with enhanced protection of the components of the system in case of sparks in the electrostatic precipitator (10). This is achieved, when the switching device (5) of the system has turn-off capability and when the system comprises a clamping circuit (11-13; 60-67).

Abstract: Provided are a hollow inner electrode constituted by an electrically conductive filter capable of capturing particulates, a cylindrical outer electrode circumferentially surrounding the electrode, a housing incorporated in a flow passage of exhaust and accommodating the electrodes and, a temperature sensor for detecting temperature of the exhaust and an electric discharge controller for controlling electric power to be distributed to the electrodes and on the basis of a detected value of the temperature sensor. When the temperature of the exhaust obtained by the temperature sensor is lowered, electric power necessary for generation of discharge plasma is distributed by the discharge controller to the electrodes and, thereby oxidizing the particulates captured by the electrode to reduce electricity consumption.

Abstract: An air purifier includes a housing, a high voltage power supply, a first electrode assembly in which a wire-like first electrode is either the only first electrode or, alternatively, is spaced sufficiently far from any other such first electrodes so as to avoid undesirable effects upon each other, and a second electrode assembly in which there are a plurality of blade-like second electrodes. The air purifier can be of the type in which air flows through the housing as a result of electro-kinetic effects. To increase air flow velocity, the voltage between first and second electrodes is relatively high, such as 23-50 kV, and the first and second electrodes are accordingly spaced apart a relatively great distance, such as at least 30 mm.

Abstract: An air purifier device includes a fan unit in an electrically conductive housing for drawing ambient air into the housing via an air inlet, and an electrically conductive dust-collecting member in the housing and disposed adjacent to an air outlet. A detecting unit is operable so as to provide a control signal in response to at least one of a change in electrical characteristics of the housing due to body contact therewith, and a change in electrical characteristics of the dust-collecting member due to excessive accumulation of dust thereon. A power control unit is operable to supply electric power to a negative ion generating unit such that a drive voltage is applied to an ionizing member of the negative ion generating unit, and is responsive to the control signal from the detecting unit to interrupt supply of the electric power to the negative ion generating unit.

Abstract: An apparatus and method for controlling voltage applied to an electrostatic precipitator is disclosed. This apparatus includes a pulsating, direct current, voltage mechanism that is operable to receive power from a single phase, alternating current voltage source, and a spiral wound filter capacitor, wherein the pulsating, direct current, voltage mechanism is electrically connected in parallel to the spiral wound filter capacitor and the spiral wound filter capacitor is electrically connected in parallel to the electrostatic precipitator. Optionally, a resistor is present to lower the transient voltage rating of the spiral wound filter capacitor. A switching mechanism may be utilized to apply differing amounts of capacitance and inductance in order to apply a range of voltage waveforms to the electrostatic precipitator to potentially maximize particulate collection efficiency for the electrostatic precipitator.

Abstract: An apparatus and method for controlling voltage applied to an electrostatic precipitator is disclosed. This apparatus includes a pulsating, direct current, voltage mechanism that is operable to receive power from a single phase, alternating current voltage source, and a spiral wound filter capacitor, wherein the pulsating, direct current, voltage mechanism is electrically connected in parallel to the spiral wound filter capacitor and the spiral wound filter capacitor is electrically connected in parallel to the electrostatic precipitator. Optionally, a resistor is present to lower the transient voltage rating of the spiral wound filter capacitor. A switching mechanism may be utilized to apply differing amounts of capacitance and inductance in order to apply a range of voltage waveforms to the electrostatic precipitator to potentially maximize particulate collection efficiency for the electrostatic precipitator.

Abstract: An improvement in an electrostatic precipitator and method for removing particulate contaminants entrained in a gas stream passed through an electrode arrangement in which particulates are charged in a first electrostatic field and subjected to a second electrostatic field to be removed and collected for further disposition. The electrode arrangement includes a charging section having a charging electrode and a field electrode, and a collecting section having a repelling electrode and a collecting electrode. The field electrode and the collecting electrode are integrated, providing a relatively compact construction, and the charging electrode and the repelling electrode are electrically separated by high voltage diodes in a single power supply arrangement such that the charging section and the collecting section each are provided with a corresponding electrostatic field operated at an optimum voltage and current for respectively charging and collecting particulate contaminants entrained in the gas stream.

Abstract: An ionizing structure for ambient air treatment wherein the structure, optionally having ceiling-mounting provisions, incorporates an ionizing element forwardly directed in the direction of airflow through the structure, an electrical power supply coupled to the ionizing element for applying thereto a stepped-up, negative, direct-current voltage of the order of several thousand volts, and a buffer, in effect, in the form of electrical circuit means, e. g. a filter, operatively interposed between the power supply and the blower for preventing feedback of eddy-voltage spikes, transients and the like as may be generated in the power supply to the operative parts of the blower, thus preventing damage to the blower.

Abstract: A method of operating an electrostatic precipitator (7) includes feeding the precipitator with electric power generated by a power supply (10) according to a regime adapted to impart between the precipitator electrodes a voltage having a DC component and an AC component. A control unit (8) measures the electrode voltage, establishes a voltage peak value and a voltage mean value, and computes the product of peak value by mean value to arrive at an index of expected performance (IEP). Operating set points are tuned so as to maximize this index of expected performance.

Abstract: A filter apparatus for use in removing mist, smoke and particles generated by a machine tool includes a mechanical first filtration stage and a second filtration stage consisting of an electrostatic precipitator. A blower device creates a stream of air for entraining and moving mist, smoke and other particles upwardly through the first and second filtration stages. Circuitry is provided selectively opening the circuit to the collector of the electrostatic precipitator. The collector is energized by a lower voltage from the ionizing field when current to the collector is interrupted. By energizing the collector of the electrostatic filter at a low voltage and by operating the blower unit at a low velocity, mist, smoke and other particles are efficiently collected without shorting the collector plates when water based metal working fluids are used.

Abstract: In a power supply for an electronic precipitator with a power electronics part, a transformer connected at the output side and a high-voltage rectifier, the transformer and the high-voltage rectifier as well as a device for measured value acquisition are situated in the immediate proximity of the electronic precipitator, and the power electronics part is situated at a location remote from the electronic precipitator and, for control, is coupled to the device for measured value acquisition via optical conductors.

Abstract: An electrical apparatus includes a reaction chamber. A stream of contaminated gasses flows through the chamber. An elongated coronating electrode is positioned in the reaction chamber for producing a corona discharge within the chamber. A multi-stage Fitch generator connected to the electrode produces a high level, rapidly pulsating voltage in the electrode. Controlled amounts of an inert gas or inert gas-air mixture are combined with the contaminated gases to provide a high concentration of inert gas in the reaction chamber. In the inert gas-enriched atmosphere, the pulsating corona discharge produces a high concentration of metastable intermediates that greatly increase the rate of chemical conversion of the contaminants. Switching circuitry allows the pulsating voltage output of the Fitch generator to be superimposed on a constant direct current voltage in the electrode, setting up an electrostatic field in the reaction chamber for removing conversion byproducts from the gas stream.

Abstract: An apparatus for charging an electrostatic precipitator, powered by a power supply and having a plurality of corona electrodes and a plurality of collector electrodes, such that a precipitator capacitance may be formed therebetween, includes a storage capacitor across the power supply, having a storage capacitance. A voltage switch is capable of selectively electrically coupling the electrostatic precipitator to the storage capacitor. The storage capacitance is sufficient to charge the electrostatic precipitator to a preselected operative voltage within a rise time greater than a first preselected value and less than a second preselected value.

Abstract: An apparatus for ionizing air to remove particulate matter. The apparatus including an ionizer and a bracket for mounting the ionizer and a bracket for mounting the ionizer in a duct or enclosure. The ionizer includes a series of electrodes which span a portion of the duct. The electrodes are energized by a high voltage circuit and an ionic wind is created between the electrode and duct. The ionic wind sweeps particles in the air to the duct which provides a collector electrode. In another embodiment, a ring collector electrode is also provided for spanning the inner portion of the duct. The high voltage circuit includes a DC power supply, a high voltage transformer, a high voltage multiplier stage and a push-pull switching circuit. The DC power supply receives AC power and generates a DC output which is coupled to the primary of the transformer. The push-pull switching circuit produces a controlled and efficient AC output in the transformer by alternately switching the primary winding.

Abstract: System for treating gases or liquids by corona discharge, comprising: a) a corona discharge space through which the gases or fluids to be treated are guided; b) a corona wire inside the corona discharge space; c) a source for supplying high voltage pulses, whereby the output of the source is connected to the corona wire; d) sensors for measuring the power dissipated in the corona discharge space; e) an electromagnetically compatible case.

Abstract: A method for charging an electrostatic precipitator, powered by a power supply and having a plurality of corona electrodes and a plurality of collector electrodes, such that a precipitator capacitance may be formed therebetween, includes a storage capacitor across the power supply, having a storage capacitance. A voltage switch is capable of selectively electrically coupling the electrostatic precipitator to the storage capacitor. The storage capacitance is sufficient to charge the electrostatic precipitator to a preselected operative voltage within a rise time greater than a first preselected value and less than a second preselected value.

Abstract: Improved ionizing structure for ambient air treatment wherein the structure incorporates an ionizing needle directed in the direction of airflow; the needle is negatively charged to produce an electrostatic field, preferably pulsating, whereby to ionize air constituent molecules, lint, and other entrained constituents, allowing the latter simply to precipitate out of the air and fall to the ground or floor beneath; in such manner ambient air within a room enclosure, for example, is cleaned for maximizing occupant enjoyment as well as for health and other reasons.

Abstract: Method for controlling, in case of flashover between electrodes in an electrostatic precipitator, the current supply to the electrodes from a controllable high-voltage direct-current source. The current supplied to the precipitator and the voltage between the electrodes of the precipitator are measured substantially continuously or at close intervals. After the flashover, the current supply to the electrodes of the precipitator is completely interrupted during a first time interval. During a second time interval directly following the first time interval, a current which is greater that the one supplied immediately before the flashover is supplied to the precipitator. Subsequently, the current is reduced to a value below the one prevailing immediately before the flashover.

Abstract: An apparatus for ionizing air to remove particulate matter. The apparatus including an ionizer and a bracket for mounting the ionizer in a duct or enclosure. The ionizer includes a series of electrodes which span a portion of the duct. The electrodes are energized by a high voltage circuit and an ionic wind is created between the electrode and duct. The ionic wind sweeps particles in the air to the duct which provides a collector electrode. In another embodiment, a ring collector electrode is also provided for spanning the inner portion of the duct. The high voltage circuit includes a DC power supply, a high voltage transformer, a high voltage multiplier stage and a push-pull switching circuit. The DC power supply receives AC power and generates a DC output which is coupled to the primary of the transformer. The push-pull switching circuit produces a controlled and efficient AC output in the transformer by alternately switching the primary winding.

Abstract: There is provided a capacitor having an end connected to the ground and the other end connected through a secondary winding of a pulse transformer to the discharge electrode. The ground side terminal of the capacitor is connected through a smoothing circuit to a positive voltage side output terminal of a base power supply circuit and a negative voltage side terminal of the base power supply circuit is connected to the discharge electrode side terminal of the capacitor. An output terminal of a pulse power supply circuit is connected to a primary winding of the pulse transformer. The base voltage and the pulse voltage can be controlled independently, and it becomes possible to apply a steep pulse with large output power to the discharge electrode.

Abstract: An improved electrostatic precipitator system is provided for use in high-grease atmospheres in which the grease is electrically conductive. The precipitator includes high-voltage insulators that are both located in areas unlikely to accumulate electrically-conductive grease and that, in themselves, can operate in a high-voltage system without tracking, even when a certain amount of conductive grease has accumulated on the insulators' surfaces. In a multi-cell precipitator system, a high-voltage insulator is provided as part of a cell-to-cell assembly that receives high-voltage electricity on one side of its insulator, and conducts that electricity to its opposite side, and is placed in a specially-shaped cut-out in the bulkhead between the cell chambers, in which the cut-out is shaped so as to minimize the amount of grease that may accumulate upon the cell-to-cell assembly's insulators.

Abstract: Electrical apparatus for removing ecologically noxious substances from gases which includes an electrical precipitator having a reaction chamber through which a stream of the gases to be cleaned passes, and which includes an elongated electrode extending into said reaction chamber for producing a corona discharge within the chamber. The apparatus of the invention includes a multi-stage Fitch generator connected to the electrode which produces a high level pulsating voltage superimposed on a constant direct current voltage. The pulsating voltage causes the electrode to produce the corona effect in the chamber, and the constant direct current voltage sets up an electrostatic field which removes unwanted products of the corona discharge from the gas stream passing through the chamber. The Fitch generator is adapted to provide pulsating voltages of sufficient amplitude and steepness to produce a high density, high energy corona discharge within the chamber.

Abstract: An electric circuit is disclosed which includes an electric fan for dispersing air, a power switch for energizing the electric fan, and a convenience outlet for supplying power through the electric circuit to an external power consuming apparatus. The convenience outlet is operable separately and independently of the electric fan. In one embodiment for use in a humidifier the electric circuit further includes a refill light, a refill light switch, and a power light. In another embodiment for use in an air purifier the circuit further includes a filter sensor, a filter replacement indicator light, an ionizer for emitting ions, a negative ion switch, an ion indicator light and a power indicator light.

Abstract: Air purification system where air is subjected to complex electrical field resulting from a DC voltage and AC frequency in kilovolt and kilohertz range respectively, applied to screen assembly in air path. DC amplitude and AC frequency self regulate to selected parameters. Parameters are selectable independently of one another.

Abstract: Silver halide radiographic sensitive materials comprising at least one silver halide photographic emulsion layer on a support, which are used according to a process which comprises exposure to radiation from a fluorescent intensifying screen which emits light having a maximum emission in the green spectral range by excitation with radiation wherein at least 1/2 of the emission energy is in the wavelength range of above about 400 nm, and carrying out development of the exposed sensitive material to form radiographic images, wherein said silver halide sensitive materials contain below about 8.6 g of silver per square meter and said at least one silver halide photographic emulsion layer contains a combination of at least one dye represented by formula (I) and at least one dye represented by formula (II): ##STR1## wherein A.sub.1 and A.sub.2 each represents a hydrogen atom or a halogen atom; A.sub.3 and A.sub.4 each represents a hydrogen atom, a halogen atom, an alkoxy group or a phenyl group; B.sub.1, B.sub.

Abstract: Photographic additives in particular water-insoluble photographic additives are rendered easier to incorporate into photographic layers by finely dividing them, mixing them with a finely divided water soluble substance and compressing the resulting mixture into the form of a tablet. The tablets which contain from about 1 to 50% by weight of the photographic additives are then dissolved in the coating composition and this disperses the water insoluble additive uniformly throughout the coating composition.

Abstract: A polyolefin layer carried on at least one surface of a polyolefin resin coated paper for use as a photographic paper support, contains a titanium oxide composition comprising 20-60 parts by weight of a rutile-type titanium oxide and 40-80 parts by weight of an anatase-type titanium oxide per 100 parts by weight of the titanium oxide composition. Such polyolefin resin coated paper is excellent in hiding power, resolving power, light resistance, whiteness, fading resistance, etc.

Abstract: Photographic additives in particular water insoluble photographic additives are rendered easier to incorporate into photographic layers by finely dividing them, mixing them with a finely divided water soluble substance and preparing granules of the mixture using a hydrophilic colloid as the binder. The granules which contain from about 1 to 50% by weight of the photographic additives are then dissolved in the coating composition and this disperses the water insoluble additive uniformly throughout the coating composition.

Abstract: Ultraviolet radiation sensitive photographic film material comprising a silver halide emulsion of at least 50 mole % silver chloride and a yellow filter dye over said silver halide emulsion layer.

Abstract: A large area integrated solid-state flat panel display is detailed in which thin film transistor addressing and drive circuitry is provided at each individual picture point with a display medium. The preferred display medium is an electroluminescent phosphor layer. An insulating layer of laminated photoresist is disposed over all electrical circuit elements except the electroluminescent drive electrodes.

Abstract: This invention relates to light absorbing inhomogeneous films and their use in luminescent display devices such as cathode ray tubes and electroluminescent panels to achieve high contrast ratio and minimal halation effect, and more particularly to an inhomogeneous film having a composition varying continuously from metal oxide to metal, and the method of making same. The metal is selected from the group consisting of tantalum and vanadium.

Abstract: A combination suitable for radiography comprising an x-ray fluorescent screen and a photosensitive silver halide recording material. The x-ray screen has more than half of its special emission above 410 nm, with its emission maximum in the wavelength range of 480 to 600 nm. The light absorption spectrum of the silver halide material corresponds with the light emission spectrum of the x-ray screen.

Abstract: A combination suitable for radiography comprising two separate x-ray fluorescent screens and a photosensitive material comprising a support with a silver halide layer coated on each surface of said support, wherein each of the fluorescent screens is arranged adjacent to one of the silver halide layers. The maximum emission of the x-ray screen is in the wavelength range of 450-570 nm, while the silver halide layers are sensitive to light in the same wavelength range.

Abstract: The incorporation of polymers containing at least 80% by weight of substituted or unsubstituted poly(vinyl imidazole) in a photographic element containing fluorescent optical brighteners immobilizes the brighteners. The photographic elements resist loss of brightness due to photographic processing or washing.

Abstract: Interpolymers from monomers containing optical brightening moieties and solubilizing groups are useful in optical brightening compositions. Photographic elements containing these optical brightening compositions have excellent light stability.

Abstract: A silver halide photographic light-sensitive material comprising a hydrophilic organic colloid layer containing a photographic additive dispersed therein using as a solvent a benzoic acid ester which has a boiling point of greater than 250.degree. C at atmospheric pressure, which is soluble in water in a proportion of less than about 10% by weight, and which dissolves water in a proportion of less than about 5% by weight. The benzoic acid ester does not have any harmful influence on the human body and does not cause environmental pollution.

Abstract: A small personal appliance is wholly contained within a unitary housing that is fully supported by its contact blades being plugged into a wall outlet. The housing includes needles for ionizing the ambient atmosphere and a carbon foam pad for collecting the ionized air. A drive circuit generate cyclically recurring pulses having a voltage which is high enough to ionize the air and low enough to preclude a formation of ozone.