Abstract: This invention relates to a composition of matter comprising associated predominantly silver nanoparticles, and a method of making the nanoparticles. It further relates to articles comprising the nanoparticles.

Abstract: Apparatus for acquiring an elongated radiographic image. The apparatus includes a flat panel electronic detector of radiographic images, the detector having a known length; and a transport mechanism for mounting the detector for movement in a direction parallel to the known length so that the detector can be positioned in sequential contiguous partially-overlapping positions to acquire a radiation image greater in length than the detector length. At least one marker is disposed in a region corresponding with each partially-overlapping position of the detector.

Abstract: The present invention relates to a method of particle separation comprising preparing a suspension of particles containing at least one recognizable target particle in a suspending solution, labeling the target particle with a conjugate marker, wherein the conjugate marker comprises at least one recognition unit for the recognizable target particle and at least one peroxidase enzyme, contacting a gelatin surface with the suspending solution, adding developer to the suspending solution in contact with the gelatin surface and in the presence of phenol to attach the target particle to the gelatin surface, and washing the gelatin surface to remove unattached particles. The method may also include detecting the presence of the target particle on the gelatin surface as well as detaching and recovering the attached particles after removal of the non-target particles.

Abstract: A silver halide photographic element comprises at least one silver halide emulsion layer comprising a silver halide emulsion comprising core/shell silver halide grains wherein the core region comprises silver bromide with from about 5 to about 20% silver iodide and the shell region comprises silver bromide with about 0.1 to about 10% silver iodide and said layer contains a fragmentable electron donor compound of the formula X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is covalently linked directly or indirectly to X, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.

Abstract: This invention comprises a photographic element comprising a support and at least one blue sensitive silver halide emulsion layer containing a tabular grain silver halide emulsion, or an emulsion in which the halide content is at least 50% chloride and no more than 5% iodide, wherein the emulsion is spectrally sensitized with at least one dye providing a peak sensitization between 446 and 500 nm and at least one dye providing a peak sensitization between 400 and 445 nm and additionally sensitized with a fragmentable electron donor of the formula: X—Y′. or an electron donor which contains an —XY′ moiety; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is H a base, &bgr;−, is covalently linked directly or indirectly to X. and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.

Abstract: Apparatus for acquiring an elongated radiographic image comprising: a flat panel electronic detector of radiographic images, said detector having a known length; and a transport mechanism for mounting said detector for movement in a direction parallel to said known length so that said detector can be positioned in sequential contiguous positions to acquire a radiation image greater in length than said detector length.

Abstract: A high chloride {100} tabular grain emulsion is prepared by creating grain nuclei containing greater than 45 mole percent bromide. Growth onto the grains under conditions favorable for high chloride {100} grain growth is conducted while maintaining (a) a temperature in the range of from 25 to 85.degree. C., (b) a pH in the range of from 3.5 to 8.5, and (c) a vAg in the range of from 120 to 200 mV. Crystal lattice field distortions are observed at the nucleation site, and the nucleation site exhibits the maximum bromide concentration, which is greater than 5 mole percent, based on silver at the site.

Abstract: A radiation-sensitive emulsion is disclosed in which at least 70 percent of total grain projected area is accounted for by tabular grains (a) having {100} major faces, (b) containing greater than 50 mole percent chloride, based on silver, (c) having a mean equivalent circular diameter in the range of from 2.0 to 5.0 .mu.m, and (d) exhibiting a mean thickness of 0.1 .mu.m or less.The emulsion is prepared by (a) precipitating up to 10 percent of the total silver forming the high chloride {100} tabular grains to create a first grain population under conditions that form a crystal lattice structure that favors the growth of high chloride {100} tabular grains, (b) thereafter rapidly introducing silver and halide ions to create a second grain population, and (c) growing the first grain population to create the high chloride {100} tabular grains by ripening out the second grain population.

Abstract: The invention relates to a method of sensitizing (111) high chloride tabular grains having {111} major faces comprising providing the high chloride tabular grains, and sensitizing using temperatures greater than 70.degree. C.

Abstract: An improved preparation of high chloride {100} tabular grain emulsions that relies on iodide ions to produce tabular grain growth is disclosed. By delaying iodide ion introduction until after the initiation of grain nucleation the proportion of total grain projected area accounted for by high chloride {100} tabular grains is increased. The projected areas of the {100} tabular grains can exceed 95 percent of total grain projected area.

Abstract: Silver halide emulsions are disclosed in which at least 50 percent of total grain projected area is accounted for by tabular grains (1) bounded by {100} major faces having adjacent edge ratios of less than 10, (2) each having an aspect ratio of at least 2, and (3) internally at their nucleation site containing iodide and at least 50 mole percent chloride. The emulsions are prepared by a process comprised of the steps of (a) introducing silver and halide salts into a dispersing medium so that nucleation of the tabular grains occurs in the presence of iodide with chloride accounting for at least 50 mole percent of the halide present in the dispersing medium and the pCl of the dispersing medium being maintained in the range of from 0.5 to 3.5 and (b) following nucleation completing grain growth under conditions that maintain the {100} major faces of the tabular grains.

Abstract: A process is disclosed of preparing an emulsion comprised of dispersing medium and folded tabular grains containing at least 95 mole percent chloride, based on total silver. This is achieved by maintaining a chloride ion concentration of at least 0.5 molar in the dispersing medium while the grain nuclei are being formed and during grain growth maintaining in the dispersing medium a pH in the range of from 1 to 8 and an effective concentration of 2-hydroaminoazine or xanthinoid morphological modifier in the range of from a 5.times.10.sup.-5 to 2.times.10.sup.-2 millimolar concentration.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a high methionine gelatino-peptizer dispersing medium having a methionine content of greater than 30 .mu.moles/gram gelatin, containing a stoichiometric excess of chloride ions of greater than 0.5 molar, a pH of at least 4.5, and a 4,6-di(hydroamino)-5-aminopyrimidine grain growth modifier, such as adenine or 4,5,6 triaminopyrimidine.

Abstract: The present invention is directed to a process of precipitating, for use in photography, a high aspect ratio silver halide tabular grain emulsion employing a dispersing medium and silver chlorobromide or silver chlorobromoiodide grains, wherein at least 50 percent of the tabular silver halide grains have a centrally located hole.

Abstract: The present invention is directed to hollow rod-shaped silver halide grains for use in photography and a process for preparation of hollow, rod-shaped grains. The rods have a hexagonal outer periphery, and a hexagonal hollow portion extending longitudinally within the grains.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR1## where Z.sup.8 is --C(R.sup.8).dbd. or --N.dbd.;R.sup.8 is H, NH.sub.2 or CH.sub.3 ; andR.sup.1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.

Abstract: A process is disclosed of preparing an emulsion for photographic use comprising forming in the presence of an xanthinoid grain growth modifier an emulsion comprised of silver halide grains and a gelatino-peptizer dispersing medium in which morphologically unstable tabular grains having {111} major faces account for greater than 50 percent of total grain projected area and contain at least 50 mole percent chloride, based on silver. After the emulsion is formed, the pH of the emulsion is lowered to inactivate xanthinoid grain growth modifier, and the inactivated xanthinoid is replaced on the tabular grain surfaces by adsorption of a photographically useful compound chosen to contain at least one divalent sulfur atom, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility.

Abstract: Apparatus for controlling the concentration of silver ions during the precipitating of a silver halide emulsion in a precipitation vessel. The introduction of a silver salt and a halide salt is controlled in accordance with a preselected program, which in turn is responsive to the silver ion concentration measured in the vessel by a silver ion sensor. Linerization of the output signal from the sensor is accomplished by converting the sensor's output voltage into a concentration voltage through the use of a Nernst equation and by transforming the concentration voltage into a variable value denoted Y representing a constant coefficient differential equation that is linear. The linear equation is then used to control the addition of the silver salt and the halide salt to the precipitation vessel.