SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
An all-solid-state, high-resolution and frequency-calibrated THz spectrometer based on optical heterodyne in low-temperature-grown (LTG) GaAs been constructed.
Alternative approaches for developing 2.0- 2.5 um single frequency semicondoctor lasers are reviewed.
High-resolution laboratory spectroscopy is utilized as a diagnostic tool to determine noise and harmonic content of balanced [9]-[11] and unbalanced [12]-[14] multiplier designs. Balanced multiplier designs suppress unintended harmonics more than -20dB. Much smaller values were measured on unbalanced multipliers.
Explore the source record for details and available documents.
We report on the phase noise properties of DFB lasers operating near 2.0 microns. Measured noise spectra indicate intrinsic laser linewidths below 1 kHz. An effective linewidth of less than 200 kHz for 5 ms measurement times is estimated.
Vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage is studied. Devices tested include optoelectronics, digital, analog, linear bipolar devices, and hybrid devices.
Provide discrete illumination to biological specimens contained in 60mm Petri dishes that are subjected to a microgravity environment.
The Biological Research in Canisters - LED (BRIC-LED) is a biological research system that is being designed to complement the capabilities of the existing BRIC-Petri Dish Fixation Unit (PDFU) for the Space Life and Physical Sciences (SLPS) Program. A diverse range of organisms can be supported, including plant seedlings, callus cultures, Caenorhabditis elegans, microbes, and others. In the event of a launch scrub, the entire assembly can be replaced with an identical back-up unit containing freshly loaded specimens.
Several instruments have been developed to measure low concentrations of hydrazine but none are completely satisfactory. A brief review is presented of current instruments such as the electrochemical cell, the ion mobility spectrometer, the mass spectrometer, the gas chromatograph, and the electronic nose.
Funneling under steady-state conditions is investigated, because this problem is simple enough to be treated rigorously and provides some qualitative insights into the more difficult transient problem.
We report on a subharmonic mixer with a broad IF bandwidth that has been developed for the Microwave Instrument for the Rosetta Orbiter (MIRO) to study water transition lines occurring near 557 GHz.
Through this program, novel blue-emitting molecules and layers based on wide-bandgap ambipolar hosts having a low energy difference between singlet and triplet excited-states were developed and their properties investigated using a wide variety of experimental and theoretical tools. We demonstrated that the efficient Förster resonant energy transfer from a novel host to a fluorescent guest leads to blue-emitting layers with a high photoluminescence quantum yield and reduced excited-state lifetime. Blue-emitting OLEDs having emissive layers with high IQE and improved device lifetime were demonstrated. Development of these novel hosts also yielded compounds that exhibited low concentration-dependent fluorescence quenching as well as high photoluminescence quantum yields, leading to the demonstration of highly efficient OLEDs using emissive layers using a single material - a significant advance towards the simplification of a device’s architecture.
Through this program, novel blue-emitting molecules and layers based on wide-bandgap ambipolar hosts having a low energy difference between singlet and triplet excited-states were developed and their properties investigated using a wide variety of experimental and theoretical tools. We demonstrated that the efficient Förster resonant energy transfer from a novel host to a fluorescent guest leads to blue-emitting layers with a high photoluminescence quantum yield and reduced excited-state lifetime. Blue-emitting OLEDs having emissive layers with high IQE and improved device lifetime were demonstrated. Development of these novel hosts also yielded compounds that exhibited low concentration-dependent fluorescence quenching as well as high photoluminescence quantum yields, leading to the demonstration of highly efficient OLEDs using emissive layers using a single material - a significant advance towards the simplification of a device’s architecture.
Explore the source record for details and available documents.