Abstract: Embodiments of this invention are directed to bio-based epoxy compositions, and method of their preparation and use. Other embodiments are directed to cured bio-based epoxies, and manufactured articles having bio-based epoxy coatings, adhesives, or composites.

Abstract: Disclosed is a novel room-temperature curable bio-based epoxy vitrimer with a simple design of the chemical structure. A hempseed oil-derived glycidyl ester type epoxy (HOEP) was synthesized and then blended with a bisphenol A epoxy (DER331) to manipulate the properties of the resulting vitrimer s. An aliphatic amine hardener, diethylenetriamine (DETA), was selected as hardener to realize the room temperature curing in presence of triethanolamine (TEOA) as the catalyst. Unlike the traditional glycidyl ether epoxy-amine the thermosets which are based on stable C-N and ether linkages, the epoxy vitrimer herein includes ester bonds with HOEP and hydroxyls formed from the reaction of amine and epoxy in its cross-linked network. Dynamic transesterification (DTER) between the ester bonds and hydroxyls take place at elevated temperatures, imparting the vitrimer significant stress relaxation behavior and repairability. This provided a viable method to produce room temperature curable epoxy vitrimer s.

Abstract: Embodiments of this invention are directed to bio-based epoxy compositions, and method of their preparation and use. Other embodiments are directed to cured bio-based epoxies, and manufactured articles having bio-based epoxy coatings, adhesives, or composites.

Abstract: The subject matter disclosed herein is generally directed to methods of recycling epoxy polymers using organic salts as catalysts in an aqueous solution. Epoxy polymers and their composites are widely used in many fields such as coatings, adhesives, wind blades, automobiles, aeronautic vehicles, and sporting goods. However, the management of thermoset composite wastes is becoming a public concern as the out of service thermoset products build up. With the increasing awareness of environmental protection and the depleting of landfill sites, it is of great importance to develop an economically viable and environmentally-friendly recycling technology of thermoset materials that is suitable to industrial scale-up production. As such, there is a clear and present need for a novel solution that is environmentally friendly and scalable in the market.

Abstract: The subject matter disclosed herein is generally directed to methods of recycling epoxy polymers using organic salts as catalysts in an aqueous solution. Epoxy polymers and their composites are widely used in many fields such as coatings, adhesives, wind blades, automobiles, aeronautic vehicles, and sporting goods. However, the management of thermoset composite wastes is becoming a public concern as the out of service thermoset products build up. With the increasing awareness of environmental protection and the depleting of landfill sites, it is of great importance to develop an economically viable and environmentally-friendly recycling technology of thermoset materials that is suitable to industrial scale-up production. As such, there is a clear and present need for a novel solution that is environmentally friendly and scalable in the market.

Abstract: One feature pertains to a radiation dosimeter comprising a microdosimeter cell array that includes a first microdosimeter cell having a first semiconductor volume configured to generate a first current in response to incident radiation. The first semiconductor volume may have at least one of a first size, a first shape, a first semiconductor type, and/or a first semiconductor doping type and concentration that is associated with a first biological cell type or a first biological cell component type. The dosimeter may further comprise a processing circuit communicatively coupled to the microdosimeter cell array and configured to generate a signal based on the first current. The signal generated may be indicative of an amount of radiation absorbed by the microdosimeter cell array. A display may be utilized by the dosimeter to show a radiation level reading based on the signal generated.

Abstract: One feature pertains to a microdosimeter cell array that includes a plurality of microdosimeter cells each having a semiconductor volume adapted to generate a current in response to incident radiation. The semiconductor volumes of each of the plurality of microdosimeter cells have at least one of a size, a shape, a semiconductor type, and/or a semiconductor doping type and concentration that is associated with one or more cells or cell components of a human eye. A processing circuit is also communicatively coupled to the microdosimeter cell array and generates a signal based on the currents generated by the semiconductor volumes of the plurality of microdosimeter cells. The signal generated by the processing circuit is indicative of an amount of radiation absorbed by the microdosimeter cell array.

Abstract: One feature pertains to a radiation dosimeter comprising a microdosimeter cell array that includes a first microdosimeter cell having a first semiconductor volume configured to generate a first current in response to incident radiation. The first semiconductor volume may have at least one of a first size, a first shape, a first semiconductor type, and/or a first semiconductor doping type and concentration that is associated with a first biological cell type or a first biological cell component type. The dosimeter may further comprise a processing circuit communicatively coupled to the microdosimeter cell array and configured to generate a signal based on the first current. The signal generated may be indicative of an amount of radiation absorbed by the microdosimeter cell array. A display may be utilized by the dosimeter to show a radiation level reading based on the signal generated.

Abstract: One feature pertains to a radiation dosimeter comprising a microdosimeter cell array that includes a first microdosimeter cell having a first semiconductor volume configured to generate a first current in response to incident radiation. The first semiconductor volume may have at least one of a first size, a first shape, a first semiconductor type, and/or a first semiconductor doping type and concentration that is associated with a first biological cell type or a first biological cell component type. The dosimeter may further comprise a processing circuit communicatively coupled to the microdosimeter cell array and configured to generate a signal based on the first current. The signal generated may be indicative of an amount of radiation absorbed by the microdosimeter cell array. A display may be utilized by the dosimeter to show a radiation level reading based on the signal generated.

Abstract: One feature pertains to a radiation dosimeter comprising a microdosimeter cell array that includes a first microdosimeter cell having a first semiconductor volume configured to generate a first current in response to incident radiation. The first semiconductor volume may have at least one of a first size, a first shape, a first semiconductor type, and/or a first semiconductor doping type and concentration that is associated with a first biological cell type or a first biological cell component type. The dosimeter may further comprise a processing circuit communicatively coupled to the microdosimeter cell array and configured to generate a signal based on the first current. The signal generated may be indicative of an amount of radiation absorbed by the microdosimeter cell array. A display may be utilized by the dosimeter to show a radiation level reading based on the signal generated.

Abstract: One feature pertains to a radiation dosimeter comprising a microdosimeter cell array that includes a first microdosimeter cell having a first semiconductor volume configured to generate a first current in response to incident radiation. The first semiconductor volume may have at least one of a first size, a first shape, a first semiconductor type, and/or a first semiconductor doping type and concentration that is associated with a first biological cell type or a first biological cell component type. The dosimeter may further comprise a processing circuit communicatively coupled to the microdosimeter cell array and configured to generate a signal based on the first current. The signal generated may be indicative of an amount of radiation absorbed by the microdosimeter cell array. A display may be utilized by the dosimeter to show a radiation level reading based on the signal generated.

Abstract: A method for assembling a compressor for use with a turbine is provided. The method includes coupling at least a first stator ring to a second stator ring via at least one fastener sized to extend through at least one stator ring opening. The method further includes coupling a shield assembly to at least one of the first stator ring and the second stator ring to facilitate reducing convection and aerodynamic bleed losses of the at least one stator ring. The shield assembly includes a downstream surface, a retaining portion, and a contoured upstream surface extending from the downstream surface to the retaining portion.

Abstract: A method for assembling a compressor for use with a turbine is provided. The method includes coupling at least a first stator ring to a second stator ring via at least one fastener sized to extend through at least one stator ring opening. The method further includes coupling a shield assembly to at least one of the first stator ring and the second stator ring to facilitate reducing convection and aerodynamic bleed losses of the at least one stator ring. The shield assembly includes a downstream surface, a retaining portion, and a contoured upstream surface extending from the downstream surface to the retaining portion.

Abstract: A method of assembling a gas turbine engine includes coupling an inner engine casing to an outer engine casing such that an annular flow path is defined therebetween, coupling a plurality of circumferentially-spaced support struts between the inner and outer casings, and coupling a plurality of circumferentially-spaced outlet guide vanes within the flow path upstream from the support struts, such that a first circumferential spacing is defined between a first guide vane and a second guide vane, and a second circumferential spacing is defined between the second guide vane and a third guide vane. The guide vanes are arranged such that the second guide vane is between the first and third guide vanes and the second circumferential spacing is different from the first circumferential spacing.

Abstract: A method of assembling a gas turbine engine includes coupling an inner engine casing to an outer engine casing such that an annular flow path is defined therebetween, coupling a plurality of circumferentially-spaced support struts between the inner and outer casings, and coupling a plurality of circumferentially-spaced outlet guide vanes within the flow path upstream from the support struts, such that a first circumferential spacing is defined between a first guide vane and a second guide vane, and a second circumferential spacing is defined between the second guide vane and a third guide vane. The guide vanes are arranged such that the second guide vane is between the first and third guide vanes and the second circumferential spacing is different from the first circumferential spacing.

Abstract: A compressor stator includes an outer casing supporting a row of stator vanes extending radially inwardly therefrom. Each vane includes pressure and suction sides extending axially between leading and trailing edges and radially between a root and a tip. The root and tip are twisted relative to a pitch section disposed therebetween. Each vane tip is radially convex adjacent a leading edge for defining an axially concave outer flowpath in the casing for reducing peak velocity of airflow for enhanced efficiency.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.

Abstract: A compressor stator includes an outer casing supporting a row of stator vanes extending radially inwardly therefrom. Each vane includes pressure and suction sides extending axially between leading and trailing edges and radially between a root and a tip. The root and tip are twisted relative to a pitch section disposed therebetween. Each vane tip is radially convex adjacent a leading edge for defining an axially concave outer flowpath in the casing for reducing peak velocity of airflow for enhanced efficiency.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.

Abstract: A compressor airfoil includes pressure and suction sides extending from root to tip and between leading and trailing edges. Transverse sections have respective chords and camber lines. Centers of gravity of the sections are aligned along a double bowed stacking axis for improving performance.