摘要:
An automated gravimetric screening system and method controls soil moisture in a plurality of potted plants to perform water deficit experiments in a greenhouse using a stationary support platform and pot design that maintains the plants in a static location during the testing. By weighing and re-watering the pots from beneath the platform, the present system and method permits an upper gantry to capture high resolution images, temperature data, or other sensor data to quantify the plant stress level or plant canopy characteristics during the experiment.
摘要:
An automated gravimetric screening system and method controls soil moisture in a plurality of potted plants to perform water deficit experiments in a greenhouse using a stationary support platform and pot design that maintains the plants in a static location during the testing. By weighing and re-watering the pots from beneath the platform, the present system and method permits an upper gantry to capture high resolution images, temperature data, or other sensor data to quantify the plant stress level or plant canopy characteristics during the experiment.
摘要:
A movable patient support includes a frame, a patient support surface supported at the frame, a base supporting the frame and having a plurality of bearing assemblies for moving the base along a floor surface. The support also includes a brake, a brake actuator for actuating the brake of at least one bearing assembly, and a brake bar coupled to the brake actuator. The brake bar is movable between a non-braking position and a braking position wherein the actuator causes the brake to move to its braking position. Further, the brake bar extends between the head end and the foot end of the frame and further has a portion extending outwardly from the brake actuator to at least close proximity to the bearing footprint defined by the bearing assemblies but within the frame footprint to thereby provide relatively easy access to the brake bar to an attendant standing adjacent one of the longitudinal sides of the frame.
摘要:
A method of forming a preform which has a glass core surrounded by an outer glass cladding with a coating of a light interactive material disposed between the core and cladding. The method includes providing a glass core having a viscosity which lies within a given preselected temperature range, followed by forming a substantially homogeneous coating of a light interactive material over the surface of the core, with the coating material having a viscosity which is equal to or less than the viscosity of the glass core. A glass cladding is formed over the coated layer, with the cladding glass having a viscosity which overlaps the viscosity of the core glass and a thermal coefficient of expansion compatible with that of the core. The light interactive material is an inorganic material which includes a metal, metal alloy, ferrite, magnetic material and a semiconductor.
摘要:
An optical fiber sensor having a central core, a cladding layer disposed about the central core, and a thin film of lithium niobate positioned between the core and the cladding layer. Each of the cladding layer and the central core are made from glass materials having different indices of refraction. The refractive index of the lithium niobate film changes when stress is applied to the optical fiber sensor. Accordingly, stress may be detected and measured by detecting and measuring the modulation of light passing through the optical fiber sensor while the stress is occurring.
摘要:
An optical fiber having a thin layer of gold positioned between the core and cladding. The gold layer is vacuum deposited on a rotating clean glass rod which will become the fiber core. The rod is inserted into a tube that will form the cladding of the fiber. The tube is sealed and placed in a hot tin bath inside a stainless steel pressure chamber that is pressurized and heated to collapse the cladding around the gold-coated core, thereby forming a fiber perform that may be pulled to form the gold metal cylinder fiber of the present invention. The fiber may be cleaved at one end and etched to expose a gold cylinder, thereby forming a highly responsive sensor.
摘要:
A stacked ceramic matrix composite lamellate assembly (10) including shear force bearing structures (48) for resisting relative sliding movement between adjacent lamellae. The shear force bearing structures may take the form of a cross-lamellar stitch (50), a shear pin (62), a warp (90) in the lamellae, a tongue (104) and groove (98) structure, or an inter-lamellar sealing member (112), in various embodiments. Each shear force bearing structure secures a subset of the lamellae, with at least one lamella being common between adjacent subsets in order to secure the entire assembly.
摘要:
Fabricating a refractory component for a gas turbine engine, such as a turbine shroud ring segment, by arranging refractory fiber tows (24) in a flaired tubular geometry (20) comprising a stem portion (21) and a funnel-shaped portion (22); impregnating the refractory fibers (24) with a ceramic matrix to form a flaired tube (20) of ceramic composite matrix material; at least partially filling the funnel-shaped portion (22) with a ceramic core (30) extending beyond the end of the funnel-shaped portion to provide a working gas containment surface (31); curing the flaired tube (20) and the ceramic core (30) together; cutting the funnel-shaped portion (22) to provide rectangular edges (27); and providing an attachment mechanism (34, 36, 38, 40) on the stem portion (21) for attaching the component to a surrounding support structure. Additional tows (24) may be introduced at intermediate stages to maintain a desired fabric density.
摘要:
Aspects of the invention relate to a system for attaching a ring seal to a vane carrier in a turbine engine such that the ring seal can radially expand and contract at least partially independently of the vane carrier. The system can also be configured to substantially restrict axial and/or circumferential movement of the ring seal. In one embodiment, the ring seal can include a plurality of radial slots circumferentially spaced about the ring seal. A pin can extend substantially through each of the slots and into operative engagement with isolation rings, which are connected to the vane carrier. In another embodiment, the ring seal and the isolation rings can include a series of axially-extending protrusions extending substantially circumferentially about each component. The protrusions on the ring seal can substantially matingly engage the protrusions on the isolation rings. The protrusions can be configured as a Hirth coupling.
摘要:
A gas turbine includes a compressor, a combustor, a turbine, and a flow path diverting an excess portion of the compressed air produced by the compressor around the turbine. The flow path conducts the excess portion into a turbine exhaust gas flow producing a cooled exhaust gas. A method of operating the gas turbine includes opening an inlet guide vane of the compressor to allow the compressor to produce an increased volume of compressed air. The increased volume exceeds a volume of compressed air needed to support combustion. An excess portion of the compressed air is directed into the exhaust gas to produce a cooled exhaust. In a combined cycle power plant, the cooled exhaust from the gas turbine may be used to warm a steam turbine portion to a desired temperature while allowing operation of the gas turbine at a power level that produces exhaust gas at a temperature higher than the desired temperature.