Results 61 to 70 of about 23,038 (167)

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

Multi-disciplinary shape optimization of an entry capsule integrated with custom neural network approximation and multi-delity approach [PDF]

, 2011
This paper describes a new integrated approach for the multi-disciplinary optimization of a entry capsule’s shape. Aerothermodynamics, Flight Mechanics and Thermal Protection System behaviour of a reference spaceship when crossing Martian atmosphere are ...
Cavallero, Claudio, Chiarelli, Cosimo, Davite, Alessio, Gallizio, Federico, Mareschi, Vincenzo, Minisci, Edmondo, Sudars, Martins   +6 more
core  

Characterization of Ultrafast Decomposition Dynamics in Nitrate Esters

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT Ignition of energetic materials initiates chemical reactions on atomic length scales within femtoseconds, making these reactions difficult to investigate experimentally. The technique of femtosecond time‐resolved mass spectrometry (FTRMS) can capture molecular rearrangement and bond‐breaking events in isolated molecules with sub‐50 femtosecond
Madison K. Minvielle, Erica Britt, Hugo A. López Peña, Katharine Moore Tibbetts   +3 more
wiley   +1 more source

Synthesis and Characterization of an Azido Nitrofurazanyl Ether: An Energy‐Rich Heterocyclic Plasticizer With a Low Glass Transition Temperature

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT We report on the synthesis and characterization of 3‐(2‐(2‐azidoethoxy)ethoxy)‐4‐nitro‐1,2,5‐oxadiazole (NFPEG2N3), which is a liquid nitrofurazanyl ether that was designed to be an energy‐rich plasticizer for glycidyl azide polymer (GAP)‐ and nitrocellulose (NC)‐based formulations.
P. Lieber, A. Omlor, U. Schaller, T. M. Klapötke   +3 more
wiley   +1 more source

Development of NMP‐001, A Nitromethane‐Based Green Propellant

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT This paper discusses the development of a model monopropellant that is aimed at exploring the applicability of nitromethane‐based propellants as an alternative to hydrazine. This approach addresses the challenges faced by HAN‐, ADN‐based propulsion by being more cost‐effective while providing similar performance figures.
Maxim Kurilov, Joshua Haase, Christoph U. Kirchberger, Stefan Schlechtirem   +3 more
wiley   +1 more source

Sliding Mode Control in Aerospace Applications: A Survey

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Sliding mode control (SMC) enjoys robustness to matched and unmatched (in the case of minimum phase input‐output dynamics) bounded perturbations, and finite time convergence. Second‐order and higher‐order sliding mode control systems (2‐SMC/HOSMC) retain all the advantages of sliding mode control, but in addition can be applied to systems of ...
Yuri Shtessel, Christopher Edwards
wiley   +1 more source

A review of the ONR/NAVAIR research option combustion instabilities in compact ramjets, 1983-1988 [PDF]

, 1989
This paper consists of two parts summarizing two portions of the ONR/NAVAIR Research Option. The option began in 1983 and continued for five years, involving 11 organizations.
Culick, F. E. C., Schadow, K. C.
core  

The Evolution of Autonomous Systems for Planetary Cave Exploration: A Review

Journal of Field Robotics, EarlyView.
ABSTRACT The exploration of Subsurface Access Points (SAPs), such as lava tubes on the Moon and Mars, has gained significant interest due to their potential as stable environments shielded from surface radiation and temperature extremes. These sites are considered high‐value targets for detecting water and signs of ancient life, and assessing their ...
Sarah Swinton, Daniel Mitchell, Jamie Blanche, Euan McGookin, David Flynn   +4 more
wiley   +1 more source

Experimental measurements of the permeability of fibrous carbon at high temperature

, 2016
A series of experiments was performed to obtain permeability data on FiberForm(R), a commercial carbon preform used for manufacturing thermal protection systems. A porous sample was placed in a quartz flow-tube heated by an isothermal furnace.
Cochell, Thomas J., Mansour, Nagi N., Martin, Alexandre, Panerai, Francesco, Schroeder, Olivia M., White, Jason D., Wright, Michael J.   +6 more
core   +1 more source

Do Single‐Sex STEM Programs Have Merit? If So, for Whom, on What Measures?

Science Education, EarlyView.
ABSTRACT Single‐sex STEM programs—defined here as voluntary, gender‐segregated extracurricular or supplemental activities (e.g., summer camps, workshops, robotics clubs, internships, or citizen science initiatives)—have experienced heightened popularity and scrutiny amid efforts to increase diversity in STEM fields.
Chen Chen, Tomihiro Ono, Gerhard Sonnert, Susan Sunbury, Philip Sadler   +4 more
wiley   +1 more source