Abstract: A spinning apparatus is disclosed according to the invention having a drafting zone comprising at least four roll pairs for drawing a sliver comprising one or more types of staple fibers. The rolls pairs include a back roll pair, intermediate roll pairs and a front roll pair and the distance between the nip of the back roll pair and the nip of the adjacent intermediate roll pair, and the distances between the nips of adjacent intermediate roll pairs is no more than the effective fiber length of the longest staple fiber type in the sliver. The drafted sliver may be spun into yarns at high speeds, such as the speeds used in air jet spinning apparatus to provide yarns having increased strength and reduced defects. The present invention also includes a method of forming high quality and high uniformity yarns by advancing a sliver through a drafting apparatus and thereafter spinning the sliver into yarn.

Abstract: Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.

Abstract: A method and apparatus are disclosed for externally and noninvasively determining the temperatures of chemical reactions inside a plurality of separate closed vessels that are made of materials that substantially transparent to microwave radiation but that are poor conductors of heat. The method comprises exposing a plurality of substantially microwave-transparent of vessels containing chemical reagents therein to microwave radiation, concurrently measuring the temperature of the reagents inside a first vessel using a first temperature sensor inside the first vessel and while measuring the temperature of the exterior of the first vessel using a second temperature sensor positioned externally to the first vessel, and immediately thereafter successively measuring the temperature of the exterior of the remainder of the vessels using the second sensor.

Abstract: The invention is a method and apparatus for forming a plurality of stackable items into a vertically stacked load and thereafter delivering an aligned stack of items positioned on a pallet for eventual transportation while minimizing the misalignment of the stackable items. The apparatus comprises a conveyor for delivering items to be stacked, a vertically moveable conveyor portion, a horizontally reciprocating platform for securing the lifted item, and a retaining front wall and two side walls for aligning the stacked items. The method comprises lifting an item to a position above a stacking position, securing the item in its lifted position, delivering a succeeding item into a position beneath the lifted item, lifting the succeeding item to a position immediately beneath the lifted item, releasing the secured item to drop onto the succeeding item, lifting the item and succeeding item together, and repeating the steps until reaching a desired stacking height.

Abstract: A spinning apparatus is disclosed according to the invention having a drafting zone comprising at least four roll pairs for drawing a sliver comprising one or more types of staple fibers. The rolls pairs include a back roll pair, intermediate roll pairs and a front roll pair and the distance between the nip of the back roll pair and the nip of the adjacent intermediate roll pair, and the distances between the nips of adjacent intermediate roll pairs is no more than the effective fiber length of the longest staple fiber type in the sliver. The drafted sliver may be spun into yarns at high speeds, such as the speeds used in air jet spinning apparatus to provide yarns having increased strength and reduced defects. The present invention also includes a method of forming high quality and high uniformity yarns by advancing a sliver through a drafting apparatus and thereafter spinning the sliver into yarn.

Abstract: The invention is a method and apparatus for separating by a pivoting motion a stack formed of a plurality of layers of die cut corrugated board and thereafter delivering separated portions of the stack while minimizing damage to the respective portions. The apparatus comprises a conveyor for delivering stacked portions to be separated, a means for securing portions of the stacked board to portions of the conveyor, and a means for pivoting a portion of the conveyor and a secured stacked portion of the board thereon to thereby pivotally separate the stacked portions from one another along a connecting thin paper web.

Abstract: A method is disclosed for recovering surface-ready silicon carbide substrates from heteroepitaxial structures of Group III nitrides on silicon carbide substrates. The method comprises subjecting a Group III nitride epitaxial layer on a silicon carbide substrate to a stress that sufficiently increases the number of dislocations in the epitaxial layer to make the epitaxial layer subject to attack and dissolution in a mineral acid, but that otherwise does not affect the silicon carbide substrate, and thereafter contacting the epitaxial layer with a mineral acid to remove the Group III nitride while leaving the silicon carbide substrate unaffected.

Abstract: Light emitting diodes are disclosed which have increased external efficiency and are formed from silicon carbide substrates. Diodes are produced by a method which includes directing a beam of laser light at one surface of a portion of silicon carbide, and which the laser light is sufficient to vaporize the silicon carbide that it strikes to thereby define a cut in the silicon carbide portion; and then dry etching the silicon carbide portion to remove by-products generated when the laser light cuts the silicon carbide portion. The resulting diode structure includes reticulate patterned sidewalls that promote increased light emission efficiency.

Abstract: A method for microwave assisted chemical processes is disclosed that comprises applying sufficient microwave radiation to a temperature-monitored mixture of reagents, with at least one of the reagents being thermally responsive to electromagnetic radiation in the microwave range, and based on the monitored temperature, to maintain the added reagents at or closely about a predetermined temperature while substantially avoiding thermal dilution (or before substantial thermal dilution can occur) that otherwise would have been caused by the addition of the reagents to one another.

Abstract: A process for destroying dioxane in a water vapor stream includes combusting the stream to decompose dioxane contained therein. The process is particularly useful for removal of dioxane from byproducts streams which result during the production of polyester.

Abstract: A method of obtaining high quality passivation layers on silicon carbide surfaces by oxidizing a sacrificial layer of a silicon-containing material on a silicon carbide portion of a device structure to substantially consume the sacrificial layer to produce an oxide passivation layer on the silicon carbide portion that is substantially free of dopants that would otherwise degrade the electrical integrity of the oxide layer.

Abstract: A double heterostructure for a light emitting diode comprises a layer of aluminum gallium nitride having a first conductivity type; a layer of aluminum gallium nitride having the opposite conductivity type; and an active layer of gallium nitride between the aluminum gallium nitride layers, in which the gallium nitride layer is co-doped with both a Group II acceptor and a Group IV donor, with one of the dopants being present in an amount sufficient to give the gallium nitride layer a net conductivity type, so that the active layer forms a p-n junction with the adjacent layer of aluminum gallium nitride having the opposite conductivity type.

Abstract: A high resolution, high brightness, full color display is provided having a liquid crystal pixel selectably addressable during a predetermined time period, a set of at least one red, one green, and one blue color light emitting diodes positioned adjacent the liquid crystal pixel for emitting light through the liquid crystal pixel, and means connected to the liquid crystal pixel for addressing the liquid crystal pixel a plurality of times during the predetermined time period for each color so as to provide persistence when changes in color are perceived by the human eye.

Abstract: Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal to levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.

Abstract: A metal-semiconductor field-effect-transistor (MESFET) is disclosed that exhibits reduced source resistance and higher operating frequencies. The MESFET comprises an epitaxial layer of silicon carbide, and a gate trench in the epitaxial layer that exposes a silicon carbide gate surface between two respective trench edges. A gate contact is made to the gate surface, and with the trench further defines the source and drain regions of the transistor. Respective ohmic metal layers form ohmic contacts on the source and drain regions of the epitaxial layer, and the edges of the metal layers at the trench are specifically aligned with the edges of the epitaxial layer at the trench.