Results 41 to 50 of about 495 (169)

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

Purification and Properties of Polyvinyl Nitrate and Its Compatibility With Solid Oxidizers

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT Polyvinyl nitrate (PVN) is a nitrate‐ester energetic binder that can be produced directly from polyvinyl alcohol—a cheap commodity feedstock—thereby offering potential cost and supply‐chain advantages over binders based on nitrocellulose and other specialty polymers.
Stephen Spice, Monica C. Chandwani, Carole A. Morrison, Colin R. Pulham   +3 more
wiley   +1 more source

Direct Measurement of Explosive Impulse From Contact to the Ultra‐Near Field

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT Measurement of impulse from explosive charges in contact and ultra‐near‐field regimes remains poorly characterised due to the short duration of loading, high strain rates, and the difficulty of obtaining direct momentum‐based measurements.
R. Alford, R. Hazael, R. Critchley, L. Humphreys   +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

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

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

Journal of Field Robotics, EarlyView.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang, Hao Zhou, Dalin Zhou, Zhaojie Ju   +3 more
wiley   +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

National Policy Coherence Counts for Reducing Inequality in Global Climate and Development Agendas

Sustainable Development, EarlyView.
ABSTRACT International institutions promote policy coherence as crucial to the effective and fair implementation of global sustainability agendas, though the evidence for its benefits is slim. We present here the first systematic cross‐country dataset on the consequences of national government efforts to promote policy coherence for vulnerable groups ...
Katherine Browne, Adis Dzebo, Zoha Shawoo, Mario Cardenas, Pierrick Chalaye, Alexia Faus Onbargi, Cassilde Muhoza, Patricia Nicdao, Nokwethaba Makhanya, Navam Niles, Priyatma Singh   +10 more
wiley   +1 more source

Strategy for One‐Step Optimization of Metal Oxide Passivating Contact Materials for Si Heterojunction Solar Cells through Growth Angle Variation

Small, EarlyView.
A one‐step oblique angle reactive sputtering approach enables simultaneous tuning of bulk and interfacial stoichiometry in a metal oxide/ silicon heterojunction. In case of vanadium oxides, growth angle variation controls the formation of stoichiometric SiO2, ternary SiOx(V) interlayer, and phase purity of vanadium oxide, considerably simplifying the ...
Aparajita Mandal, Alexis Franquet, Hans Hofsäss, Tapobrata Som   +3 more
wiley   +1 more source

Defining Lines of Defense Against Change Propagation Using Cause‐Consequence Analysis

Systems Engineering, EarlyView.
ABSTRACT Complex engineered systems are the core of modern society. So that engineered systems and infrastructure can be sustainable and offer value over the course of their lifespan, there is a growing need for such systems to be changeable. Yet, establishing and operationalizing changeability can be challenging due to the potential for change ...
Lindsey Jacobson, Scott Ferguson
wiley   +1 more source