Abstract: An ion exchange scrubber has a housing, and a partition plate installed within the housing. The partition plate partitions an inner space of the housing in longitudinal direction into two chambers that are filled with a predetermined amount of aqueous solution. The upper end portions of the two partitioned chambers communicate with each other. At least one cartridge is installed at the upper portion and has an ion exchange resin. The ion exchange resin removes a harmful substance contained in the gas. By repeatedly pumping the aqueous solution from one side chamber to the other side chamber, and immersing and cleaning the contaminated ion exchange resin in the aqueous solution, the contaminated gas can be effectively processed even with a small amount of water.

Abstract: A rotor includes a high-temperature section and a low-temperature section on its circumference. It is possible to absorb and separate carbon dioxide gas in an effluent or exhaust gas simply by rotating the rotor. Therefore, it is possible to obtain a reliable absorbing/separating system. The system can be remarkably simplified, the regenerating cost thereof can be considerably reduced, and the maintenance thereof is easy. A fixed type of system has similar advantages. Lithium zirconate, an alkali metal oxide, and/or an alkali earth metal oxide is used as an absorbing/separating agent. Such an absorbing/separating agent is chemically and mechanically stable, and can absorb and release carbon dioxide gas stably and reversibly.

Abstract: Air laden with biodegradable volatile organic compounds is passed sequentially through a first filter bed containing a biologically inert filter media and a second filter bed containing a biologically active filter media. Water is present in the biologically active filter media and the biologically inert filter media. Water that drains from the second filter bed is collected and supplied to the first filter bed.

Abstract: A vapor recovery system for a fuel storage tank. The system includes a pair of VOC adsorbent canisters that alternately recover VOC vapors from the fuel tank ullage or are regenerated. Regeneration of the VOC adsorbent canisters is provided by exhausting the VOC vapors from the VOC canisters using a vacuum pump and back into the fuel tank ullage. When the operating pressure of the fuel tank ullage is elevated, an auxiliary VOC adsorbent canister is operated in parallel with the pair of canisters in order to recover the increased amount of VOC vapors in the tank ullage.

Abstract: A method for purifying a minority constituent and concentrating it in a majority constituent of a gas mixture that also contains one or more other minority constituent(s) employs (i) a selective permeation step, (ii) next, a purification step, and (iii) finally a concentration step. In the selective permeation step, an initial gas mixture is passed through a membrane to yield a gas mixture that is enriched in the first minority constituent. In the purifying step, the first minority constituent is absorbed by a solid adsorbent which has a strong affinity for the first minority constituent, then following an elution step, a gas mixture that contains essentially only the majority constituent and the first minority constituent is formed.

Abstract: A reactor for the processing of gaseous media, including two planar beds of active material separated by a gap. A gaseous medium to be processed is fed inwardly around the periphery of the reactor beds into the gap between the reactor beds and collected from their outer surfaces.

Abstract: A water dispenser has an apparatus for removing water from the air and an apparatus for treating the water to provide a consumer with potable water.

Abstract: A method and apparatus for compressing and drying a gas, typically air, are provided in which a multistage compressor is employed to produce interstage and final stage compressed gas. Regenerative adsorbent is employed to dry the final stage compressed gas. Interstage gas is used to regenerate the saturated adsorbent. Preferably, two beds of regenerable adsorbent are provided, each operable in a drying mode and a regeneration mode. In the drying mode, final stage compressed gas is passed through the bed of adsorbent in order to be dried, until the adsorbent is saturated. In the regeneration mode, moisture is removed from the saturated adsorbent by a stream of interstage compressed gas. The two beds are preferably alternately operated in the drying mode and the regeneration mode, in order to provide a continuous process.

Abstract: A system for drying a gas, such as air, includes a source of gas to be dried, a multi-stage compressor having an inlet connected to the source, and a dryer connected interstage to the compressor and to the outlet of the compressor. The dryer is connected interstage to the compressor between a compression stage and a heat exchanger of one of the compressor stages for regenerating a first desiccant filled tower. The dryer is also connected to the outlet of the compressor for drying the gas using a second desiccant filled tower. A communication structure can be activated to connect the first tower to the outlet of the compressor for drying the gas using the first tower, and to connect the second tower interstage to the compressor for regeneration of the second tower.

Abstract: The invention relates to a water supply and drainage type microorganic deodorizing system, by which a clogging of deodorizer can be effectively prevented in order to decrease a deodorizing capacity, wherein deodorization chambers are provided in two stages in the tower main body, offensive odor constituents are gradually adsorbed by filters of the deodorization chambers as ordered by decomposing action of microorganisms, and decomposed in order to completely deodorize. Furthermore, by providing a water sprinkling system of replenishing water in relation to the filters the performance of the filters can be restored, and furthermore, by providing a water diluting system WC which dilutes cleansing water of the filters, drainage can be prevented from being contaminated, in accordance with drainage standards.

Abstract: Water containing contaminants is removed from a gas or liquid stream and then treated to separate the water from the contaminants. The water is separated using a condenser and a semi-permeable membrane so that it is pure enough to be disposed-of in the local environment by evaporation. The accumulated contaminants may be removed separately for controlled disposal, or reintroduced into the original stream as an alternate method of disposal.

Abstract: Process gases from microelectronic device fabrication processes are pumped through a filter unit including a plurality of absorbers for absorbing water entrained within the process gases. Residues deposited within the filtering unit are removed by spraying water on the absorbers. Water is prevented from escaping from the filtering unit into other portions of an exhaust gas system or into the environment by providing a curtain of pressurized, inert gas, within the filtering unit.

Abstract: A column packing for use in the scrubbing of gases by aqueous liquid, the packing comprising material that is electrically conductive and material that is non-conductive with such materials being intimately mixed with each other, such that the packing as a whole provides the gas-liquid surface for absorption and the conductive material in particular serves as a bipolar electrode for electrolysis.

Abstract: SF.sub.6 gas is collected from the inside of a gas insulated machine during maintenance and inspection and is refined. Compositions of the refined SF.sub.6 gas are analyzed and confirmed to be reusable at the site. In the process of SF.sub.6 gas collecting and refining, acidic gases are neutralized and removed by a dry method using filters and the refined SF.sub.6 gas is collected in a collecting tank. In particular, after the refining, the composition of the collected SF.sub.6 gas is measured and confirmed by analysis equipment to quantitatively confirm whether or not the refined SF.sub.6 gas is reusable.

Abstract: Air is supplied along a pipeline to an apparatus for separating an oxygen-enriched gas stream from the air by vacuum swing adsorption. The oxygen-enriched gas stream is supplied to a burner which fires into a furnace. A hot gas stream leaves the furnace through an outlet. Steam is raised from the hot gas in a waste heat boiler. Steam so raised flows through one or more of the eductors to draw through a pipeline the vacuum necessary for the operation of the vacuum swing adsorption apparatus.

Abstract: A thermodynamic pressure swing adsorption cycle utilizing "loudspeaker" diaphragms or pistons which are located at the top and bottom of a column containing a bed of adsorbent. The diaphragms are vibrated out of phase with each other so as to provide a displacement wave in the gas mixture within the bed of adsorbent. In addition to this displacement wave the gas is compressed prior to upward displacement and the gas pressure is lowered before the downward displacement by way of a second set of "loudspeakers" which form the side walls of the column. The second set of loudspeakers vibrate in phase with each other and operate at the same frequency as the displacement speakers.

Abstract: A vacuum swing adsorption apparatus for separating a gas mixture includes a pipeline along which the vacuum is able to be drawn. The apparatus is provided with a plurality of eductors each connected to the pipeline 6 and in parallel with the other eductor respective stop valves. The stop valves are arranged and operable so as to select the number of eductors in communication with the pipeline. Thus the degree of vacuum to which the apparatus is subjected may be varied.

Abstract: A process for the purification of gases loaded in particular with chemical residues, in particular of the exhaust air from printing equipment, in which process the gas to be purified is drawn off from the regions producing the impurities and led via piping to an arrangement of adsorber-filter cartridges that serve for the separation of the impurities from the gas and are periodically separated in a cyclical manner from the exhaust flow for the carrying out of a regeneration process.

Abstract: The present invention relates to a combined cycle system of enhanced efficiency. The system comprises a top stage, such as a fuel cell, a partial oxidation reactor or a heat engine, and an oxygen-enriching device, such as a temperature swing adsorption device or a chemical reactor bed device, as its bottom stage. The bottom stage uses waste heat produced by the top stage to enrich the oxygen content of air that is inputted to the bottom stage, thereby producing an oxygen-enriched gas mixture as the bottom stage output. This output mixture constitutes a superior oxidant which is fed back as an input for the top stage, thus enhancing the energy conversion efficiency, cheapness, and compactness of the combined cycle system as compared to that of ordinary fuel cells, partial oxidation reactors and heat engines that use unenriched air as their oxidant input.

Abstract: A compact organic solvent recovery system includes a backup treatment apparatus for environmentally safe treatment of an organic solvent leaking into a gas exiting an adsorption tower packed with an adsorbing material such as particulate active charcoal or active carbon fiber. Adsorption treatment of organic solvents includes introducing an organic solvent containing gas to be treated into an organic solvent recovery apparatus including an adsorption tower packed with adsorbing material. By subsequently introducing steam into the adsorption tower, the organic solvents are desorbed. By introducing the treated gas discharged from the organic solvent recovery apparatus into the backup treatment apparatus, the organic solvents leaking into the treated gas are adsorbed, and the gas treated in the backup treatment apparatus is simultaneously discharged as purified gas.

Abstract: A process and device for scrubbing flows of gaseous effluents loaded with polluting substances, wherein the effluents are caused to circulate through a device including an array of scrubber units (4a to 4n) juxtaposed in an enclosure (3), each containing materials adsorbing the substances. When the adsorbing load thereof is saturated and for the scrubber units (4) to regain the scrubbing capacity thereof, they are selectively and successively isolated by a mobile collector (8) during the time required for their desorption by heating and for the substances to be transferred by an auxiliary fluid (a fraction of the circulating effluents for example or a gas delivered selectively to the inlet of the scrubber unit to be desorbed by an auxiliary circuit), and the substances mixed with the auxiliary fluid are possibly transferred towards a reactor (10) suited for removing them. The process can be applied for concentrating and scrubbing of polluting substances such as VOCs or gas dehumidification.

Abstract: An absorber fluid return circuit is provided for a volatile liquid vapor recovery system. The vapor recovery system includes at least one adsorbent bed for capturing volatile liquid vapor, a vacuum pump for regenerating the adsorbent bed, an absorber tower for condensing volatile liquid vapor and an absorber fluid source. The absorber fluid return circuit includes an absorber fluid return pump having an inlet and outlet and a first conduit for directing absorber fluid from the absorber tower to the inlet of the return pump. A second conduit directs absorber fluid from the outlet of the return pump to the absorber fluid source. A variable speed motor drives the return pump. The variable speed motor is controlled by a controller operatively connected to a sensor for sensing the level of absorber fluid in the absorber tower, a variable speed AC drive for varying the speed of the drive motor.

Abstract: In a method for recovering and/or purifying water which is absorbed from a humid atmosphere, the moisture from the air is adsorbed on a suitable medium (3) in a defined space, whereupon by the application of heat the moisture is brought to a condenser (1) where it passes into a liquid state (10) and is collected in a suitable manner. In order to improve the efficiency of this method the defined, sealed space is opened for the adsorbing medium (3), for free access to air at night-time and is closed during the hot day-time period. Condensed water is passed out through a collecting funnel (2) and a channel (5) to a collection container (6). A device is also described in the form of a housing with walls (7) which can be opened and closed, in which there is located an adsorbing medium (3). In the upper part of the housing there is provided a condenser (1). The condenser (1) is equipped with a drop collector (2) which is connected to an outlet pipe (5) to a collection container (6).

Abstract: A process for separating organic compounds, such as solvents, from gases, e.g. waste gases of paint shops. The gases to be treated are conducted in an adsorber over a sorbent which is composed of particulate activated carbon in an oxidic carrier. The charged sorbent is regenerated by passing therethrough, preferably according to the countercurrent principle, a heated regeneration gas, the regeneration gas charged with desorbate is cooled so that organic compounds condense and can then be separated, whereupon the regeneration gas is reheated and reused for the desorption of the charged sorbent. Heating of the regeneration gas as well as cooling of the regeneration gas charged with desorbate are, at least partially, effected by a heat pump. It will be expedient to provide at least two adsorbers which are charged and regenerated alternately. An apparatus for carrying out the process is additionally described.

Abstract: An apparatus for purifying feed air by adsorption of water vapor and carbon dioxide therefrom includes a purification vessel in which are defined vertically arrange chambers and another purification vessel in which are defined vertically arranged chambers. None of the chambers is in a series flow relationship with any of the others. Each chamber contains a bed of one or more adsorbents which is able to adsorb water vapor and carbon dioxide from the feed air and which forms a reversible part of a gas flow path extending between locations external of the vessels. Valves are associated with the vessel and are operable to permit during a first adsorption period of time simultaneous flows of air to to purified through at least two of the chambers and during a second regeneration period of time simultaneous reverse flows of regeneration gas through the same chambers.

Abstract: An apparatus is provided for recovering volatile liquid vapor from an air-volatile liquid vapor mixture. The apparatus includes first and second reaction vessels. Each of these reaction vessel includes a bed of adsorbent having an affinity for the volatile liquid vapor. The apparatus also includes a pump and an absorber for regenerating either bed of adsorbent. Further, the apparatus includes a polisher including a polisher bed of adsorbent having an affinity for the volatile liquid vapor. This polisher bed adsorbs volatile liquid vapor and substantially clean air is exhausted when initially regenerating one of the two beds of adsorbent in the first and second reaction vessels. Still further, the apparatus also includes a cooperating valve and conduit system for interconnecting the other components. Further, the invention relates to a related process for recovering volatile liquid vapor and a method of reducing backpressure in a volatile liquid vapor recovery system or unit.

Abstract: A regeneratable adsorber for adsorbing adsorbable contaminates from a fluid stream containing same is disclosed. The adsorber includes an adsorber housing in which there is a fluid stream inlet and a fluid stream outlet. The adsorber also includes a plurality of adsorber chambers which are arranged in an indexable wheel configuration. Each chamber includes an electrically conductive adsorbent, such as a monolithic activated carbon, a set of electrical conductors in contact with the adsorbent, and an inlet and outlet. A chamber is either in contact with a source of contaminate fluid or a desorbent fluid used to regenerate the adsorber. The adsorber includes selectively indexed chambers for adsorption or desorption to provide continuous contaminate adsorption and regeneration.

Abstract: A vapor recovery apparatus is provided with an automatic flow control system. The apparatus includes first and second reaction vessels. Each reaction vessel holds a bed of adsorbent for adsorbing volatile liquid vapor and producing relatively volatile liquid vapor-free air. A vacuum pump is provided for regenerating the beds of adsorbent. A cooler and/or absorber tower is provided to recover volatile liquid vapor generated during bed regeneration. Conduits are provided for the passage of air-volatile liquid vapor mixture between the various components of the apparatus. A series of valves direct the flow of the air-volatile liquid vapor mixture through the conduits. The automatic flow control system includes a vacuum transmitter for monitoring air pressure within the apparatus at a selected point and a controller responsive to the sensed pressure for controlling the operation of the valves.

Abstract: A process and apparatus for the selective recovery of solvents from solvent gas mixtures according to which the solvent gas mixture undergoes a sorption process, individual solvent gas fractions are fractionally desorbed from the sorption agent, condensed at staggered time intervals, measured to determine their composition, and collected separately.

Abstract: In a process and installation for removing solvent vapor from exhaust air sucked from a working space, the air is fed to at least two parallel activated carbon adsorbers. Each adsorber can be switched to and fro between a charging mode in which it adsorbs solvent vapors from the exhaust air flowing through the adsorber, and a regeneration mode in which it is separated from the flow of exhaust air and flushed with water vapor and desorbed. To save energy and to reduce environmental pollution, at the end of the regeneration period each adsorber has a drying phase in which exhaust air from the working space flows through the adsorber, the air thereafter being fed to an adsorber which is operating in the charging mode.

Abstract: An apparatus capable of being used for the separation of solutes dissolved in a gaseous solvent is described. In one aspect, the apparatus includes a bed of sorbent in a container, a device which allows the gaseous solvent to pass through the bed of sorbent in a first direction, a device which allows the pressure of the gas to increase and/or the temperature of the gas to decrease, and a device which allows the gaseous solvent to pass through the bed of sorbent in a second direction. In another aspect, the device is capable of allowing the bed of sorbent to be contaminated by the solute and also be regenerated in situ.

Abstract: A vapor recovery unit comprising a vapor inlet for taking up hydrocarbon vapor from a loading facility or the like, and thereafter alternately allowing the vapor to flow to one of at least two adsorber vessels. Each adsorber vessel includes an entry port in the bottom of the adsorber vessel for receiving vapor. Hydrocarbons are retained on activated carbon beds in the adsorber vessels, resulting in purified air or other carrier gas which is removed through a discharge port also in the bottom of each adsorber vessel and released through an elevated vent to the atmosphere. Hydrocarbon vapor is desorbed from the adsorber vessel by a vacuum system and directed to a separator/absorber vessel wherein the desorbed vapor which has passed through the vacuum system is brought into contact with a hydrocarbon absorbent liquid or condenser. In use, when one adsorber vessel is taking in vapor from the vapor inlet, the other adsorber vessel is having its adsorbent bed desorbed or regenerated.

Abstract: The gas stream which emanates from landfills is treated to produce a purified gas which is essentially a hydrocarbon such as methane which can be used as the fuel source in a fuel cell power plant, or can be used in other power plants which use natural gas as a fuel. The landfill gas passes through a system which removes essentially all of the hydrogen sulfide; water; organic sulfur and halogen compounds; and solid contaminants from the gas stream. The resultant purified gas stream can be cleanly flared; used to power an energy plant; or put to other useful purposes.

Abstract: A system and method for removing volatile organic compounds (VOC's) from a circulating airstream utilizes first and second adsorption beds and first and second adsorption paths alternately coupling the circulating airstream to the respective first and second adsorption beds for removing VOC's during adsorption cycles. First and second desorption loops alternately couple a desorption inert gas through the respective first and second adsorption beds for desorption and regeneration and for recovering VOC's in a VOC condenser. System parameter sensors are distributed in the first and second adsorption paths and first and second desorption loops for sensing system parameters. A programmable controller is coupled to the system parameter sensors, to flow control valves, and to the inert gas heater for controlling the system in response to sensed system parameters. The system parameter sensors include a variety of temperature, O.sub.2, VOC, pressure, and differential pressure sensors.

Abstract: An improved process for recovering one or more condensable compounds from inert gas-condensable compound vapor mixture is provided. The inert gas-condensable compound vapor mixture is flowed through a first bed of solid adsorbent whereby the condensable compounds are removed from the mixture and a residue gas stream comprised of substantially condensable compound-free inert gas is produced and disposed of, e.g., vented to the atmosphere. A second bed of solid adsorbent is evacuated by vacuum pumping using a cooled liquid seal vacuum pump. As the resulting inert gas-condensable compound vapor mixture is contacted with the cooled seal liquid of the liquid seal vacuum pump, a major portion of the condensable compounds are condensed. The condensed compounds are recovered and a portion thereof are cooled and recycled as cooled seal liquid for the vacuum pump.

Abstract: A system for compressing and drying a gas from a gas source comprises a compressor operatively connected to the source for compressing the gas. A regenerative dryer for collecting water from the gas is operatively connected to the compressor such that the compressor is within a path of gas flow between the source and the dryer. The dryer is also operatively connected to the source such that water collected from the gas and removed from the dryer does not enter the compressor. A method of compressing and drying a gas is also provided comprising the steps of: supplying a compressor with gas from a source; compressing the gas; collecting water from the gas with a regenerative dryer; regenerating the dryer by removing collected water from said dryer with a purge gas; and delivering the purge gas to the source such that no purge gas or collected water is supplied to the compressor.

Abstract: A heat-developable photosensitive material which comprises a support having thereon at least one layer containing (a) an organic silver salt, (b) a catalytic amount of a photosensitive silver halide or a compound which forms a photosensitive silver halide, (c) a reducing agent, and (d) at least one sensitizer selected from the group consisting of compounds represented by the formulae (I) and (II): ##STR1## wherein R represents an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms or an aryl group; and Q represents a group of atoms necessary to complete a rhodanine nucleus, a thiohydantoin nucleus or a 2-thio-2,4-oxazolidine-dione nucleus and wherein said compound represented by the formulae (I) and (II) include at least one carboxyl group as a substituent, and (e) a binder.

Abstract: A silver halide photographic emulsion containing, in supersensitizing amounts, the combination ofat least one compound represented by the following general formula (I): ##STR1## wherein Z.sub.1 represents the atoms necessary for forming a benzene ring or a naphthalene ring; W.sub.1 represents a sulfur atom or a selenium atom; Y represents an oxygen atom or a sulfur atom; R.sub.1 represents an alkyl group or an aryl group; and R.sub.2 represents a lower alkyl group having 1 to 6 carbon atoms in the alkyl moiety or an aryl group;At least one carbocyanine dye represented by the following general formula (II): ##STR2## wherein Z.sub.2 represents the atoms necessary for forming a thiazole ring, a selenazole ring, an oxazole ring, an imidazole ring or a pyrroline ring; Z.sub.3 represents the atoms necessary for forming an oxazole ring or an imidazole ring; R.sub.4 and R.sub.5, which may be the same or different, each represents an alkyl group; R.sub.

Abstract: A light-sensitive silver halide photographic material containing at least one compound selected from the compounds represented by the following general formula (I) and at least one compound selected from compounds represented by the following general formula (II): ##STR1## General formula (I) wherein Z represents a non-metal atomic group necessary for forming a pyrroline, thiazoline or selenazoline ring, Y.sub.1 represents oxygen, sulfur, selenium or an N-R.sub.3 group (in which R.sub.3 represents an alkyl-, alkenyl- or aryl-group), R represents hydrogen or lower alkyl, and R.sub.1 and R.sub.2 individually represent an alkyl-, alkenyl- or aryl-group; General formula (II) ##STR2## wherein P represents ##STR3## (in which R.sub.5 and R.sub.6 individually represent an alkyl-, alkenyl- or aryl-group), Y.sub.2 represents oxygen, sulfur, selenium, or an >N-R.sub.7 group (in which R.sub.7 represents an alkyl-, alkenyl- or aryl-group), and R.sub.4 represents an alkyl-, alkenyl- or aryl-group.

Abstract: A silver halide photographic emulsion containing a combination of at least one merocyanine dye free of acidic groups and a benzotriazole compound which can produce a slightly soluble silver salt by reaction with silver ion, where the solubility product of the resulting silver salt is smaller than that of silver chloride, in effective supersensitizing amounts which exhibits reduced fog and a markedly increased spectral sensitivity.

Abstract: A silver halide photographic emulsion containing at least one sensitizing dye represented by the following general formula (I), ##STR1## in which Z represents an atomic group necessary for forming a benzoxazole nucleus or a naphthoxazole nucleus; R.sub.1 represents an aliphatic group; R.sub.2 represents an alkyl group, an allyl group or an aryl group; R.sub.3 represents an alkoxycarbonylalkyl group, an alkoxyalkyl group, an N-(N,N-dialkylaminoalkyl)carbamoylalkyl group, an N-(N,N,N-trialkylammoniumalkyl)carbamoylalkyl group or an N,N,N-trialkylammoniumalkyl group, with R.sub.2 being a phenyl group where R.sub.3 is an alkoxycarbonylalkyl group; X represents an acid anion; and n represents 0 or 1.

Abstract: A supersensitized silver halide photographic emulsion which contains at least one dye of the formula: ##STR1## wherein Z.sup.1 represents the atoms necessary to complete a benzisoxazole ring; Q.sup.1 represents the atoms necessary to complete a 2-thiooxazolidine-2,4-dione ring, a rhodanine ring or a 2-thiohydantoin ring; and R.sup.1 represents an aliphatic group, in combination with at least one cyanine dye or merocyanine dye which contains no benzisoxazole ring.

Abstract: The present invention relates to light-sensitive photographic material with a light-sensitive heavy metal compound, e.g. a silver halide, and a spectral sensitizer. The spectral sensitizer is a compound in which the radicals of a sensitizing dyestuff are covalently bonded to amino, imino, hydroxyl, mercapto, carboxylic acid or carboxylic acid amide groups of a natural hydrophilic colloid, preferably gelatin.The invention also relates to new sensitizing dyes which are dinuclear cyanine dyes or merocyanine dyes which have attached either to a heterocyclic nucleus of the dye or to its methine chain a group which is reactive with a hydrophilic colloid.

Abstract: A silver halide photographic emulsion containing a spectrally sensitizing amount of a sensitizing dye represented by the general formula (I) ##STR1## and a sensitizing dye represented by the formula (II) ##STR2## wherein Z.sub.1 and Z.sub.2 each is an atomic group necessary to complete a benzoxazole ring or a naphthoxazole ring; R.sub.1 is an alkyl group or an allyl group; R.sub. 2 is an alkyl group or an allyl group; R.sub.3 is an unsubstituted lower alkyl group, a hydroxyalkyl group or a carboxyalkyl group; R.sub.4 is same as R.sub.1 ; R.sub.5 is an alkyl group, an allyl group or a phenyl group; R.sub.6 is an alkoxycarbonylalkyl group, a hydroxyalkoxyalkyl group, an acyloxyalkoxyalkyl group, an N-(N,N-dialkylaminoalkyl)carbamoylalkyl group, an N-(N,N,N-trialkylammonium)carbamoylalkyl group or an N,N,N-trialkylammoniumalkyl group; X.sup.- is an acid anion; and n is 0 or 1.

Abstract: A photographic silver halide emulsion containing at least one dinuclear merocyanine sensitizing dye, and at least one compound represented by the following formula: ##STR1## wherein D represents a divalent aromatic group, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 each represents a hydrogen atom, a hydroxyl group, an alkoxyl group, an aryloxy group, a halogen atom, a heterocyclic group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alkylamino group, a cycloalkylamino group, an arylamino group, a heterocyclic amino group, an aralkylamino group, or an aryl group.

Abstract: Sensitization of silver halide emulsions by merocyanines and cationic cyanines and the stability of this sensitization is improved by addition of heterocyclically substituted thioureas of the formula ##EQU1## wherein R.sup.1 is alkyl, alkenyl or arylR.sup.2 is alkyl, cycloalkyl or aryln is 0 or 1, andZ completes a 5- or 6-membered heterocyclic group, preferably one which also contains a sulfur atom.