Abstract: An attachment for supersonic thermal spray equipment by which inert shield gas is directed radially outwardly about the central core of a supersonic, particle-carrying flame to isolate the same from ambient atmosphere. The shield gas is injected tangentially against the inner surface of a constraining tube attached to and extending from the discharge end of the thermal spray gun nozzle, causing the shield gas to assume a helical flow path which persists until after it exits the tube and impacts the work piece. A process using the shielding apparatus with a high-velocity, thermal spray gun and employing oxygen and hydrogen as gases of combustion and inert gas to introduce metal powder, having a narrow particle size distribution and low oxygen content, into the high-velocity combustion gases, produces significantly improved, high-density, low-oxide metal coatings on a substrate.

Abstract: An apparatus and method are disclosed for measuring the fluorescence and absorbance of a liquid sample. A sample tube is provided that has an external surface and a bore therethrough for containing a sample fluid. A cladding fluid coats the bore of the sample tube to provide a smooth surface adjacent to the sample fluid. Excitation radiation is directed along the bore and detector means are provided to detect the excitation radiation, fluorescent radiation, and non-absorbed radiation. Comparator means compare the signals from the presence and concentration of various constituents in the liquid sample.

Abstract: Synthetic layered structures, which may be semiconductor structures, are modified, both laterally and vertically, to provide novel electronic, optoelectronic, and optical properties. This is accomplished by selective intermixing of such layered structures through selective irradiation with laser beam or electron beam energy sources to effect interaction between neighboring regions, to a degree dependent on the energy density, while avoiding physical damage to the layered structures.

Abstract: The present invention provides an apparatus and method for fluorescence detection. An ellipsoidal cylinder having a first focal line, a second focal line and an internal reflective surface is provided. An excitation source is disposed on the first focal line and a sample container is disposed on the second focal line. Filter means are disposed between the excitation source and the sample container. Both fluorescence detector and reference detector means are provided to detect, respectively, the fluorescence radiation and excitation radiation. Comparator means compare the signal from the fluorescence and reference detectors to determine the presence and concentration of fluorescent material within the sample container.

Abstract: An apparatus and method for delivering excitation radiation to a sample and collecting radiation emanating from the sample. The sample is placed in a deep well which consists of a wall and a bottom end closed by a membrane to form a sample recepticle. A GRIN lens is provided that has a first surface and a second surface, the second surface being inserted into the deep well. A point source of light on the first surface of the GRIN lens is conditioned by the lens and, subsequently, emanates from the second surface of the lens towards the membrane. Reflected, luminescent of fluorescent radiation from the sample is incident on the second surface of the lens, passes through the lens to emanate from the first surface toward collection means, a detector and any desired processing.