Abstract:
The present invention is a novel method for freeform fabrication. Specifically, the method of solid freeform fabrication has the steps of: (a) preparing a slurry by mixing powder particles with a suspension medium and a gelling polysaccharide; (b) making a layer by depositing an amount of said powder slurry in a confined region; (c) hardening a selected portion of the layer by applying a gelling agent to the selected portion; and (d) repeating steps (b) and (c) to make successive layers and forming a layered object. In many applications, it is desirable to remove unhardened material followed by heating to remove gellable polysaccharide then sintering.
Abstract:
The invention is a method and apparatus using high cerium concentration in the anolyte of an electrochemical cell to oxidize organic materials. The method and apparatus further use an ultrasonic mixer to enhance the oxidation rate of the organic material in the electrochemical cell.
Abstract:
A method for producing an ion beam having an increased proportion of analyte ions compared to carrier gas ions is disclosed. Specifically, the method has the step of addition of a charge transfer gas to the carrier analyte combination that accepts charge from the carrier gas ions yet minimally accepts charge from the analyte ions thereby selectively neutralizing the carrier gas ions. Also disclosed is the method as employed in various analytical instruments including an inductively coupled plasma mass spectrometer.
Abstract:
Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, high temperature capability refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. The invention may be incorporated into a high temperature process device and implemented in situ for example, such as with a DC graphite electrode plasma arc furnace. The invention further provides a system for the elemental analysis of process streams by removing particulate and/or droplet samples therefrom and entraining such samples in the gas flow which passes through the plasma flame. Introduction of and entraining samples in the gas flow may be facilitated by a suction pump, regulating gas flow, gravity or combinations thereof.
Abstract:
An apparatus and method of operating the apparatus, wherein a waste feed material is vitrified for subsequent use or disposal, particularly for disposal of hazardous or noxious waste material which can be difficult or expensive to dispose of. The apparatus copmrises a melt zone constructed in an apparatus above ground (200, 217, 214, 216) and the melt zone lined with a backfill material (226) if refractory properties are needed. The feed material is fed (218) into the melt zone through a cover (216) and, if necessary combusted to an ash, whereupon the heat of combustion is used to melt the ash to a molten condition. Electrodes (220) may be used to maintain the molten feed material in a molten condition, and to maintain homogeneity of the molten materials. The molten material is withdrawn, e.g. via a weir (222) cooled or quenched and then disposed of or further processed (224).
Abstract:
Laser shock peening/processing (LSP) has been used to strengthen fatigue-critical areas in metal parts. Notwithstanding the advantages, one negative effect of LSP occurs at the boundary of the LSP-treated area. In LSP, the laser pulse induces a compressive stress in the material in the area on the surface (and to some extent in the subsurface) of the laser spot. Because the net residual stress in the material must be zero, compensating tensile residual stresses can be created in a boundary region surrounding the laser spot. This region of tensile stress at the surface of the part may be the site of further failure in the specimen if it is not reduced to an acceptable level. The tensile stresses may be reduced by further laser shocking the specinem surface in the boundary region with lower-energy pulses. Since lower energy fluence generally gives lower compensating tensile stress, this secondary LSP essentially reduces or eleminates the tensile compensating region caused by the primary laser shocking and replaces it with a lower compensating tensile region associated with the secondary shocked region further out from the fatigue-critical area.
Abstract:
A thermal storage mixture activated by exposure to microwave energy is provided. The thermal storage mixture comprises a liquid phase of a microwave active fluid; and a solid phase suspended within the microwave active fluid. The solid phase is preferably selected from material having a melting point at or below a temperature to which the liquid phase is heated, during use. The thermal storage mixture may be utilized in a container, to provide a thermal storage construction (heating construction) comprising a seat cushion having a thermal storage unit therein, to advantage, is described. Further, a process of storing thermal energy for release over an extended period of time is described.
Abstract:
The method and apparatus of the present invention relate to cryogenically cooling (15) a thermoluminescent material (18), exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to "room temperature", and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.
Abstract:
An apparatus useful in immunoassay of a fluid, light is directed to an optical sensor wherein the light is transmitted to a replaceable optical device that is responsive to index of refraction in a sensing region thereof that is exposed to the fluid. One portion of the light is transmitted via a compensation path that includes the sensing region to a first detector. Another portion of the light is transmitted via a sensing path that includes the sensing region to another detector. In one embodiment a rationing device receives an output from each detector and provides a signal responsive to the ratio of the outputs. The replaceable optical device typically comprises a pair of channel waveguides in directional coupling arrangement, or a pair of channel waveguides in an interferometer arrangement, or a ridge waveguide having a curved or serpentine path configured so that nonspecific sensing effects are compensated.