Results 91 to 100 of about 228,330 (246)

In‐situ Analysis of Paste Properties in Resonant Acoustic Mixers for Quality Monitoring

Propellants, Explosives, Pyrotechnics, EarlyView.
Quality monitoring is important to ensure manufacturing robustness and achieve consistent properties. For the emerging technology resonant acoustic mixing, this work uses motor data to detect differences in particle content in formulations and variations in powder feedstock properties.
Alexandra Dobbs, Mitchell Messer, Zac Doorenbos, Blair Brettmann   +3 more
wiley   +1 more source

Analysis of Meteorological Data Obtained During Flight in a Supercooled Stratiform Cloud of High Liquid-Water Content [PDF]

Flight icing-rate data obtained in a dense and. abnormally deep supercooled stratiform cloud system indicated the existence of liquid-water contents generally exceeding values in amount and extent previously reported over the midwestern sections of the ...
Kline, Dwight B., Perkins, Porter J.
core   +1 more source

Characterization of Structure, Properties, and Energetic Performance of a 1:1 Ammonium Dinitramide‐3,4‐Diaminofurazan Cocrystal

Propellants, Explosives, Pyrotechnics, EarlyView.
Ammonium dinitramide (ADN) and 3,4‐Diaminofurazan (DAF) form a 1:1 energetic cocrystal. We report its crystal structure and spectroscopic signature and evaluate thermal stability, decomposition behavior, hygroscopicity, and combustion properties. Propellant performance calculations benchmark the material against guanylurea dinitramide (GuDN) and ...
Peter Schultz, Uwe Schaller, Thomas Heintz   +2 more
wiley   +1 more source

Baseline Assumptions and Future Research Areas for Urban Air Mobility Vehicles [PDF]

NASA is developing Urban Air Mobility (UAM) concepts to (1) create first-generation reference vehicles that can be used for technology, system, and market studies, and (2) hypothesize second-generation UAM aircraft to determine high-payoff technology ...
Antcliff, Kevin, Kohlman, Lee, Silva, Chris, Whiteside, Siena   +3 more
core   +1 more source

A Study on Preventing Thermal Runaway of Contaminated Ammonium Nitrate Prill in Bulk Storage

Propellants, Explosives, Pyrotechnics, EarlyView.
Schematic illustration of a contaminated region of ammonium nitrate prill undergoing exothermic decomposition, producing gases containing NOx. The interstitial flow of these heated gases rapidly raises the temperature of ammonium nitrate along the flow path.
Pramith Priyananda, Alex M. Djerdjev, Nathan Paris, Brian S. Hawkett   +3 more
wiley   +1 more source

NASA aviation safety reporting system [PDF]

The origins and development of the NASA Aviation Safety Reporting System (ASRS) are briefly reviewed. The results of the first quarter's activity are summarized and discussed.
Billings, C. E., Funkhouser, H., Huff, E. M., Lauber, J. K., Lyman, E. G.   +4 more
core   +1 more source

Reduced‐Order Modeling of Energetic Materials Using Physics‐Aware Recurrent Convolutional Neural Networks in a Latent Space (LatentPARC)

Propellants, Explosives, Pyrotechnics, EarlyView.
Physics‐Aware Recurrent Convolutional Neural Networks (PARC) can reliably learn the thermomechanics of energetic materials as a function of morphology. This work introduces LatentPARC, which accelerates PARC by modeling the dynamics in a low‐dimensional latent space.
Zoë J. Gray, Joseph B. Choi, Youngsoo Choi, H. Keo Springer, H. S. Udaykumar, Stephen S. Baek   +5 more
wiley   +1 more source

Quantitative Technology Assessment in Space Mission Analysis [PDF]

New technologies will need to be developed to create feasible concepts for NASA's ambitious missions of the future, but quantitative assessments of the impacts that technologies have on systems or architectures are sporadic and often inadequate.
Arney, Dale C.
core   +1 more source

Classification of Fog Life‐Cycle Phases Using Ground‐Based and Satellite‐Based Observations

Quarterly Journal of the Royal Meteorological Society, EarlyView.
In this study, the life‐cycle phases of radiation fog events—formation, maturity, and dissipation—are automatically classified at a ground station in Southwest Germany based on visibility trends and thresholds. We demonstrate that visibility detects radiation fog phases effectively, while its combination with ceilometer data can detect the life‐cycle ...
Maria Laura Pinilla, Eva Pauli, Johannes Antenor Senn, Jan Cermak   +3 more
wiley   +1 more source

A balloon ozone measurement utilizing an optical absorption cell and an ejector air sampler [PDF]

Stratospheric ozone was measured from a balloon utilizing an ultraviolet absorption cell. The ambient air was sampled by means of an aspirator attached to the output end of the optical cell.
Ashenfelter, T. E., Hilsenrath, E.
core   +1 more source