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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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This dataset contains the stem RNA-seq data of Populus tremula x P. alba genotypes of RGA triple knockout. Populus genotypes in this study includes the empty vector control (EV, Cas9-19) and three independent RGA triple mutants, 267-17 (RGAX4KO_17), 267-2
It has been challenging to simultaneously improve photosynthesis and stress tolerance in plants. Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism that facilitates plant adaptation to water-limited environments. We hypothesized that the ectopic expression of a CAM-specific phosphoenolpyruvate carboxylase (PEPC), an enzyme that catalyzes primary CO2 fixation in CAM plants, would enhance both photosynthesis and abiotic stress tolerance. To test this hypothesis, we engineered a CAM-specific PEPC gene (named AaPEPC1) from Agave americana into tobacco. In comparison with wild-type and empty vector controls, transgenic tobacco plants constitutively expressing AaPEPC1 showed a higher photosynthetic rate and biomass production under normal conditions, along with significant carbon metabolism changes in malate accumulation, the carbon isotope ratio δ13C, and the expression of multiple orthologs of CAM-related genes. Furthermore, AaPEPC1 overexpression enhanced proline biosynthesis, and improved salt and drought tolerance in the transgenic plants. Under salt and drought stress conditions, the dry weight of transgenic tobacco plants overexpressing AaPEPC1 was increased by up to 81.8% and 37.2%, respectively, in comparison with wild-type plants. Our findings open a new door to the simultaneous improvement of photosynthesis and stress tolerance in plants.
Necessity of vehicle and motor designers of solid- propellant motors to consider upper stage, performance and thrust vector control requirements
Bending vibration equations for rocket boosted vehicle controlled by vectored thrust - structural dynamics
Optimal control and trajectory optimization in aperiodic discrete time functional systems
Caratheodory unified approach to Hamilton-Jacobi theory in variational calculus problems of optimal control
Vortex valve for hot gas flow modulation in secondary injection thrust vector control system
Electrode misalignments effects on thrust vector control for Kaufman electric rocket thrustors, noting implications for SERT 2 mission
Mission and planetary vehicles characteristics affecting design of solid propellant motors and thrust vector control systems in planetary orbiters and landers
Computer design to realize digital filter to be used as compensator in hybrid simulation of Saturn 5 thrust vector control system
Mission and planetary vehicles characteristics affecting design of solid propellant motors and thrust vector control systems in planetary orbiters and landers
Nonlinear system controllability by application of linear control vectors
Optimal constant output feedback gains for linear multivariable systems, noting control vector as time invariant function of output vector
Electric propulsion systems integration into SERT 2 spacecraft, discussing launch imposed environment, thrust vector control, thrustor breakdown, power conditioning, etc
Electric propulsion systems integration into SERT 2 spacecraft, discussing launch imposed environment, thrust vector control, thrustor breakdown, power conditioning, etc
Beam vector control from ion bombardment thrustors with dual grid electrostatic, movable screen electrode and discharge chamber extraction systems
A description of a mathematical model reference system is presented which provides redundancy management for an electrohydraulic servoactuator. The mathematical model includes a compensation network that calculates reference parameter perturbations induced by external disturbance forces. This is accomplished by using the measured pressure differential data taken from the physical system. This technique was experimentally verified by tests performed using the H-1 engine thrust vector control system for Saturn IB. The results of these tests are included in this report. It was concluded that this technique improves the tracking accuracy of the model reference system to the extent that redundancy management of electrohydraulic servosystems may be performed using this method.
Detailed mass properties are presented for a gimbaled, fixed thrust, regeneratively cooled engine having a coaxial pintle injector. The baseline design parameters for this engine are tabulated. Mass properties are also summarized for several other engine configurations i.e., a hinge nozzle using a Techroll seal, a gimbaled duct cooled engine and a regeneratively cooled engine using liquid injection thrust vector control (LITVC). Detailed engine analysis and design trade studies leading to the selection of a regeneratively cooled gimbaled engine and pertaining to the selection of the baseline design configuration are also given.