Results 51 to 60 of about 362 (192)

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

Additively manufactured aluminium nested composite hybrid rocket fuel grains with breathable blades

Virtual and Physical Prototyping, 2023
Hybrid rocket engines suffer from the restricted mechanical properties and low regression rates of current polymeric fuel grains. We propose a three-dimensional printed aluminium (Al) nested composite fuel grain with millimetre-scale lattice pores ...
Dandan Qu, Xin Lin, Kun Zhang, Zhiyong Li, Zezhong Wang, Guoliang Liu, Yang Meng, Gengxing Luo, Ruoyan Wang, Xilong Yu   +9 more
doaj   +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

One-Dimensional simulation of internal ballistic of a Hybrid Rocket Engine [PDF]

علوم، فناوری و کاربردهای فضایی
A one-dimensional code was developed to simulate the performance of hybrid rocket engines. In this code, the conservation equations of mass, momentum and energy are solved in one-dimensional and inviscid form.
Hadi Rezaei
doaj   +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

Oxygen–Methane Torch Ignition System for Aerospace Applications

Aerospace, 2020
A new ignition system, based on a CH4/O2 torch has been developed by the Chemical Propulsion Laboratory of the University of Brasilia. Designed to ignite a hybrid rocket, this device has been improved to be used in testing of solid and liquid ramjet ...
Olexiy Shynkarenko, Domenico Simone
doaj   +1 more source

Small‐Scale Magnetic Soft Robots for Medical Applications: From Laboratory to Clinical Use

SmartBot, EarlyView.
Small‐scale magnetic soft robots are emerging as promising platforms for minimally invasive diagnosis and therapy in complex in vivo environments. This review compares untethered and tethered medical magnetic robots in parallel across five translational stages, from basic performance testing to clinical evaluation.
Xingxing Ke, Shizhi Li, Tianrui Zhang, Yue Zhong, Songyang Li, Shuo Zhang, Zhiping Chai, Menghao Pu, Zisheng Zong, Haochen Yong, Xingxing Dong, Lanting Huang, Zhen Deng, Shuaizheng Yan, Yue Zhang, Zhaoju Zhu, Mingzhu Zhu, Linze Li, Ruiquan Chen, Shu Zhang, Chong Wu, Di Wu, Lei Yang, Rui Chen, Tongzhi Niu, Hongling Qin, Han Ding, Bingwei He, Siqi Wu, Zhigang Wu   +29 more
wiley   +1 more source

On Soot and Its Environmental Impact in Hybrid Rocket Engines

Aerospace
Hybrid rocket engines (HREs) are increasingly considered for space transportation due to their inherent safety, cost-effectiveness, and operational flexibility.
Valerio Santolini, Christian Paravan
doaj   +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

Crash Behavior of DP800–DP1000 Advanced High‐Strength Steel’s Dissimilar Resistance Spot Welded Joints Under Quasi‐static and High Strain Rates

steel research international, EarlyView.
The high‐strain‐rate behavior of resistance spot‐welded DP800–DP1000 joints is investigated. Results show that microstructural gradients across BM–HAZ–FZ govern hardness, strain rate sensitivity, and failure modes. While strength increases with strain rate, energy absorption is controlled by ductility, with DP800–DP800 joints showing superior ...
Pankaj Shrivastava, Velaphi Msomi
wiley   +1 more source