Abstract: The present invention provides improved processes and apparatus for reacting high flow rates of one or more gaseous reactants in tubular reactors. The improved processes and apparatus allow such reactions to be carried out with a low pressure drop across the reactor and without excessive erosion due to solid particles carried with or picked up by the gaseous reactants. A process of this invention is basically comprised of the steps of swirling a gaseous reactant which may contain or pick up solid particles in a first annular plenum chamber followed by a second larger diameter annular plenum chamber and then introducing the gaseous reactant and solid particles into a reactor by way of two or more radial slots whereby said gaseous reactant and solid particles are caused to flow into said reactor and are uniformly distributed therein.

Abstract: A composition curable by a metathesis reaction upon mixing its components and comprising an olefin-containing substrate, a metathesis catalyst, and a reaction control agent for slowing the progress of the metathesis reaction. The metathesis catalyst is a ruthenium or osmium carbene complex catalyst having high activity and good air stability. In one embodiment, the catalyst is free of phosphine ligands. The reaction control agent is an organic compound that contains carbon-carbon double and/or triple bonds and one or more Group 14 atoms and is present in an amount effective to slow the progress of the metathesis reaction. In one embodiment, the olefin-containing substrate may comprise one or more oligomers or polymers having a >20 wt. % linear siloxane (Si—O—Si) backbone tethered and/or end-capped with functional olefin groups, such as cycloalkenyl groups.

Abstract: A shelf-stable two-part self-adhering dental composition and method.

Abstract: A composition curable by a metathesis reaction upon mixing its components and comprising an olefin-containing substrate, a metathesis catalyst, and a reaction control agent for slowing the progress of the metathesis reaction. The metathesis catalyst is a ruthenium carbene complex catalyst, such as one containing an alkylidene ligand with basicity higher than that of tricyclohexylphosphine (PCy3) and a neutral electron donor ligand with a basicity lower than that of PCy3, whereby the catalyst initiates the metathesis reaction of the composition upon mixing with the substrate. The reaction control agent is an organic compound that contains carbon-carbon double and/or triple bonds and one or more Group 14 atoms and is present in an amount effective to slow the progress of the metathesis reaction.

Abstract: A method of controlled curing by a metathesis reaction upon mixing its components, the method including the step of mixing an olefin-containing substrate, a metathesis catalyst, and a reaction control agent. The metathesis catalyst is a ruthenium carbene complex catalyst, such as one containing an alkylidene ligand with basicity higher than that of tricyclohexylphosphine (PCy3) and a neutral electron donor ligand with a basicity lower than that of PCy3, whereby the catalyst initiates the metathesis reaction of the composition upon mixing with the substrate. The reaction control agent is effective to slow the progress of the metathesis reaction and prevent its completion in the absence of an elevated temperature. The control agent may be a hydrocarbon containing carbon-carbon double bonds and/or triple bonds, or maybe a modified hydrocarbon with one or more Group 14 or 15 atoms.

Abstract: A sliding bridge eyeglass frame provides salespersons and customers the ability to insure that a proper interpupillary distance between telescope oculars is achieved during a fitting session. The demonstration frame device of the present invention includes first and second bridge portions which are slidably and reversibly fixedly attached to thus allow a customized fitting for particular customers. Once proper interpupillary distances are achieved, the first and second frame members are secured together such that proper dimensions and configurations can be obtained for production of a final product.

Abstract: The invention relates to light-generating instruments, which are small, compact and convenient to use. More particularly, the light-generating instruments are generally powered by air, electricity, or light provided by the operating unit, such as the dental chair. Air, electricity, and light provided by the dentist's chair allow for convenience to the dentist while eliminating potential risks and hazards associated with use of an electrical cord to power the instrument.

Abstract: A housing for a magnification loupe is provided having a body portion for an eyepiece lens and a nose portion for an objective lens. The body portion for the eyepiece lens includes outer circumferential threads over which the objective nose portion fits. The objective nose portion includes a pin slot defining an arc across the body of the nose. The arc is configured such that a pin may be secured through the holes in the nose piece to co-act with the threads of the eyepiece body such that radial movement is prohibited.

Abstract: A novel air knife. The novel air knife is circumferential. That is, the novel air knife injects a gas stream along the inside walls of the air knife. The air knife can be advantageously placed at or near the entrance to a suspension vessel to reduce buildup of solid materials transported to the suspension vessel. The gas stream is injected at a rate sufficient to reduce the buildup of solid materials on the walls of the air knife (and thus at the entrance to the suspension vessel). The air circumferential air knife is particularly useful in a TiCl4 production process for reducing buildup of hygroscopic cyclone dust at the entrance to a suspension vessel.

Abstract: A delivery system for supplying a single dose quantity of dental impression material. The system includes a dispenser having first and second chambers sized to contain first and second components of the single dose of dental impression material. The chambers are sealed by a closure that is movable from a sealed position to permit dispensing of the components through a mixing tip. The resulting dental impression material may be applied directly to a patient's dental anatomy and/or to a dental tray.

Abstract: A dispenser has first and second reservoirs configured to contain first and second components of a single dose of a multi-component dental adhesive. The reservoirs are sealed by closures which are slidably received in the reservoirs. When the closures are moved from first positions to second positions, the contents of the reservoirs may be accessed with an adhesive applicator. An applicator configured to be used with the dispenser has a collar spaced from a tip of the applicator, whereby the applicator may be used to move the closures while ensuring that the tip does not contact the closures.

Abstract: A storage and mixing capsule 10 for separately storing a pair of ingredients therein and providing a structure for efficiently and reliably mixing the ingredients to form an amalgam. The capsule has two components: a first receptacle 12 and a second receptacle 14. The first receptacle 12 includes an interior compartment 16 for receiving an alloy and includes a piercing element 24 attached to a portion of the inner wall 26. The second receptacle 14 includes an interior compartment 30 for receiving mercury. The second receptacle 14 further includes a rupturable seal 38 disposed across the open bottom end 36 of the second receptacle 14. The capsule 10 further includes a conduit 54 extending from the capsule 10 which is used as a passageway for air to move from the interior of the capsule 10 to the exterior of the capsule 10 or for an inert gas to move from the exterior of the capsule 10 to the interior of the capsule 10 to create an interior atmosphere which prevents the oxidization of amalgam components.

Abstract: A housing for a magnification loupe is provided having a body portion for an eyepiece lens and a nose portion for an objective lens. The body portion for the eyepiece lens includes outer circumferential threads over which the objective nose portion fits. The objective nose portion includes a pin slot defining an arc across the body of the nose. The arc is configured such that a pin may be secured through the holes in the nose piece to co-act with the threads of the eyepiece body such that radial movement is prohibited.

Abstract: A hand held dental instrument for curing light-curable compounds comprises a housing and an array of solid state, light emitting junctions or dies for generating light having wavelengths within a narrow band of wavelengths (e.g. 400-500 nm). Preferably, a peak wavelength of 470 nm is generated. The device further comprises an optical fiber light pipe for capturing the light and transmitting a beam of the light to a work surface containing a light-curable compound. An optical lens or lenses may be used for focusing the light into the light pipe.

Abstract: Improved methods for producing titanium dioxide slurries. The output from a micronizer is passed through a condenser to condense the steam and form an aqueous slurry of titanium dioxide, which can in most cases then be further concentrated as desired or which can be sold or used without further concentration, instead of passing the micronizer output to apparatus for separating the TiO2 from the steam, as is currently practiced in the art. The resultant slurry from the condenser is in a further refinement preferably sent to an agitated storage tank together with dispersant and anti-settling compounds to aid in preventing settling of the titanium dioxide solids out of the slurry. To help facilitate condensation of the steam/pigment mixture sent to the condenser, a portion of the condensed slurry is in yet a further refinement pumped from the slurry storage tank to a heat exchanger. The output from the heat exchanger is then fed to the condenser to facilitate the condensing of the steam in the condenser.

Abstract: A composition and a method of use as a dental restorative. A series of highly alkoxylated tri-functional monomers are used as a low viscosity monomer in a photo- or self-curable dental composition that resulted in low polymerization shrinkage. The mechanical strength of the restorative material was not compromised. The restorative composition may be used as a dental filling material, a cement, a liner/base, or an adhesive.

Abstract: A delivery system for supplying a single dose quantity of a two-component dental restorative material includes a dispenser which contains first and second components of the dental restorative material. The first and second components are stored in separate chambers which are sealed with a closure. To dispense the dental restorative material, a tip is installed to an end of the dispenser to move the closure to an open position, whereafter plungers may be depressed into the chambers to dispense the single dose of dental restorative material through the tip. The tip may be provided with a static mixer to mix the components as it is dispensed.

Abstract: An instrument and method for curing light-curable compounds in the mouth of a patient, the instrument comprising a housing and a plurality of solid state, light-emitting elements on a substrate supported by the housing. The elements form a collective array on the substrate operable for collectively emitting light having wavelengths within a narrow band of wavelengths. An optical focusing device is positioned to intercept the light emitted by the array of elements and includes a non-imaging optical device which is operable for collimating the light from the array into a beam to be directed onto a compound for curing the compound. A disposable sleeve covers the housing and array and may incorporate the optical focusing device. The sleeve is removed and discarded after use to eliminate the need to autoclave the instrument.

Abstract: The present invention provides a handheld portable, efficient instrument for curing light-curable compounds. The instrument comprises a housing, a light emitted structure supported in the housing, and a reflector configured to interface with the light emitting structure such that light emitted is captured and directed by the reflector onto a light-curable compound. The reflector maximizes the amount of light transferred and contacting the light-curable compound thereby reducing the instrument's power requirements and improving efficiency. The light emitting structure comprises state of the art, energy efficient, light generating dies. The curing light instrument may also have a self-contained power supply lending portability and convenient of use.

Abstract: A security device for attaching laptop computers and the like to a desk includes a body portion which is to be received in an aperture of the work surface of a work station or desk. The body portion includes a grommet which fits within the aperture with a flange at the top. A lock plate bears against the underside of the work surface to hold the grommet in place. A combination of pawls and lock teeth hold the lock plate in place. Within the grommet there is a cable lock to which the computing device is attached.