Abstract: A method of recovering quantitatively trace amounts of scandium from aqueous solutions containing large amounts of other metals consists of reducing any manganese and iron in the solution to the divalent states of manganese and iron. The solution is then adjusted to a pH from about 1.9 to about 2.1 and passed through a column of the ion exchange resin in the hydrogen form having an iminodiacetic acid functionality. The scandium is absorbed on the column and any base metals and rare earth metals which were also absorbed are removed by eluting with a dilute acid without removing the scandium. The scandium is subsequently removed from the column by eluting with a solution containing a chelating agent such as diglycolic acid. The scandium is then recovered from the solution by precipitation, filtering, washing, drying and calcined to the oxide.

Abstract: A process for making a homogeneous yttria-alumina doped silicon nitride article is described. A uniform coating of yttria and alumina is applied to the surface of silicon nitride particles by a chemical application of the hydroxides of yttrium and aluminum followed by drying and a subsequent conversion of the hydroxides to the corresponding oxides. The resulting powder is formed into an article and pressureless sintered to a density greater than 99% of theoretical.

Abstract: A method of making Y couplers and grating optical waveguides of the present invention comprises exposing the polydiacetylene to an e-beam or a similar exposing means causing a change in the index of refraction of the polydiacetylene. In the case of e-beam exposure, the optical component patent is produced by directly controlling the e-beam which does not require any physical and/or chemical preparation of the polydiacetylene. The depth of penetration of the e-beam is controlled by the scanning rate and intensity of the e-beam. The optical gratings, fabricated by e-beam exposure technique, also inherit nonlinear optical properties which can be utilized in nonlinear optical applications.

Abstract: A method of preparing ceramic monolithic structures with an internal cavity and passageways is described. A thin sheet of a ceramic material is formed by spreading the material on a glass plate with a doctor blade. Individual sheets of the material are cut or punched to form predetermined holes, channels or various shapes therein. These individual sheets are then stacked to form a layered structure. A supporting media such as paraffin wax is injected into the holes and channels to completely fill them with the media. The layered structure is then pressed by unipressing and/or isostatic pressing followed by a prefiring step to remove the supporting media. Once the supporting media had been completely removed, the layered structure is then sintered to form a monolithic structure containing precise predetermined internal cavity and passageways.

Abstract: A method for preventing the hydration/solubilization of the protective oxide coating of a phosphor is described. The method involves coating of the oxide coated phosphor particles with a continuous hydrophobic coating. After the phosphor particles are coated with the continuous hydrophobic coating and the continuous hydrophobic coating cured, they are added to a water-based suspension and subsequently processed into a lamp.

Abstract: A cutter bit holder which can be used as a point attack mine tool and a road milling tool is described. The cutter bit holder has a replaceable cutter tip which can be replaced in the field when the cutter tip is worn by unscrewing the flange from the shank of the holder and replacing the worn cutter tip with a new one.

Abstract: A method for eliminating carbonaceous contaminants and preventing the hydration/solubilization of the oxide coating of a phosphor is described. The method involves the annealing of the oxide coated phosphor at a temperature and for a period sufficient to preclude adversely affecting the protective oxide coating on the phosphor during subsequent water-based suspension processing without detrimentally altering the phosphor. After annealing the phosphor is cooled and then added to a water-based suspension. The optimum conditions for annealing a manganese activated zinc silicate phosphor or a calcium halophosphate phosphor having a protective aluminum oxide coating are the combination of a temperature between about 700.degree. C. and about 850.degree. C. and for a period of time from about 15 minutes to about 20 hours.

Abstract: A thermal shock apparatus comprises a hot gas stream impinging means, a hot gas stream impinging control means, a positioning means for the hot gas stream impinging means, and a sample holding means. A sample is subjected to an essentially instantaneous impingement of a hot gas stream upon a predetermined area of the sample when a heat gun is moved past heat deflection foils and positioned above the sample causing a thermal shock within the sample.

Abstract: A laser has been made using a Nd.sup.3+ -doped fluoro-zirconate heavy metal fluoride (HMF) glass multimode fiber which lases in a range equal to or greater than 1.32 micrometers. The fiber laser was made for forming a glass fiber from a core glass composition comprising 52.8 mole % ZrF.sub.4, 19.9 mole % BaF.sub.2, 2.5 mole % LaF.sub.3, 3.0 mole % AlF.sub.3, 19.9 mole % NaF, 0.4 mole % InF.sub.3, and 1.5 mole % NdF.sub.3 the active dopant and the composition of the cladding glass comprises 39.6 mole % ZrF.sub.4, 17.9 mole % BaF.sub.2, 4.0 mole % LaF.sub.3, 3.0 mole % AlF.sub.3, 21.9 mole % NaF, 0.4 mole % InF.sub.3, and 13.2 mole % HfF.sub.4.

Abstract: A high purity aluminum nitride is made by precipitating (CH.sub.3).sub.3 Al:NH.sub.3, washing it with hexane and pyrolyzing it to AlN. The precipitation is obtained by reacting a hexane solution of trimethyl aluminum with high purity anhydrous NH.sub.3(g), or by reaction Al(CH.sub.3).sub.3(g) and NH.sub.3(g) in a hexane solution, or by reacting Al(CH.sub.3).sub.3(g ) with NH.sub.3(1). The resulitng AlN is very pure and a density of 91.3% of theoretical has been achieved by pressing and sintering a pellet made from it as compared to a 89% theoretical density obtained by pressing and sintering a pellet made from commercial AlN powder.

Abstract: An optical waveguide made from a unitary organic film has a polydiacetylene core region and a diacetylene monomer cladding substrate region. The index of refraction of the polydiacetylene core region is greater than the index of refraction of the diacetylene monomer cladding substrate region.The method of fabricating the optical waveguide comprises depositing a diacetylene monomer film on a substrate. The diacetylene monomer film is polymerized by ion beam bombardment to a depth less than the thickness of the film. The depth of the polymerization is controlled by the ion mass and energy of the ion beam applied.

Abstract: The lumen output of a fluorescent lamp is improved by the triode radio frequency sputter coating of a continuous protective coating of vitreous alumina overlying the lamp phosphor layer.

Abstract: A silicate optical glass article is made by forming a gel from a hydrolyzed silicon alkoxide. The resulting gel is molded, cured, dried, solvents removed, heated to form a dense glass having near net shape dimensions thereby reducing expensive polishing steps to obtain the desired final dimensions and surface quality.

Abstract: A method for a quantitative separation of scandium from thorium comprises adsorption of both metals on a cation exchange resin followed by selective elution of scandium with an acidic solution of a chelating agent followed by the elution of thorium by a six normal hydrochloric acid solution.

Abstract: An efficient green emitting phosphor results from the coactivation of yttrium fluoride with gadolinium and erbium. The excitation energy absorbed by the Gd.sup.3+ centers is transferred non-radiatively to minority Er.sup.3+ centers, whose emission produces green light when excited by 275 nanometer or 378 nanometer radiation.

Abstract: A method for preparing a barium lanthanum silicate oxyapatite europium activated phosphor and a barium lanthanum silicate oxyapatite manganese 2+ and europium 2+ or europium 2+ activated phosphor having a yellow green emission when activated by 254 nm excitation comprises the steps of forming a water slurry of the raw materials followed by calcining at approximately 1050.degree. C. to form a powder. The powder is then heated to approximately 1500.degree. C. in a reducing atmosphere to form the phosphor having a yellow green emission activated by a 254 nm excitation. Fluorescent lamps containing the yellow green emitting phosphors are described.

Abstract: A high pressure sodium lamp brightness was increased 8.9%, its relative voltage stability was improved by a factor of 4, and its relative maintenance was improved by a factor of 3 over a 24,000 hour lifetest. These improvements were accomplished by the application of a fine grained alumina protctive coating on the surface of the polycrystalline alumina arc tube. The process for applying the protective coating comprises the deposition of Al(NO.sub.3).sub.3 from solution on the surface of the arc tube followed by the thermal decomposition of the Al(NO.sub.3).sub.3 to form an alumina coating on the surface of the alumina arc tube.

Abstract: A steel roughing grade coated cemented carbide cutting tool comprises WC grains equal to or less than 70 w/o of the tool substrate, from about 5 to about 10 w/o of a cobalt bonding phase and the remainder being metal carbide grains selected from the group TiC, TaC, NbC, HfC and combinations thereof. The average WC grain size is from about 0.9 to about 1.3 microns and less than 10% of the WC grains have a size less than 0.5 microns. The coated cemented carbide tool is coated with an adherent refractory coating layer. The coated cemented carbide cutting tool can be used to machine steel at rough and heavy rough cutting conditions.

Abstract: A method for fabricating large, greater than one centimeter cross section, high density silicon nitride by injection molding process has been developed. The method requires use of a controlled starting powder, a novel binder removal process, a prefiring step followed by isopressing and conventional sintering.

Abstract: A method for fabricating injection molded ceramic shapes suitable for densification by sintering or hot isostatic pressing has been developed. The method is applicable to ceramic articles of large, complex cross sections, greater than one centimeter, which are generally prone to external cracking during binder removal. The method requires use of a controlled starting powder, and a novel binder removal process to obtain an externally crack-free article.