Results 61 to 70 of about 4,679 (234)

Prenatal and Perinatal Outcomes in Fetuses With Macrocystic Congenital Pulmonary Airway Malformations: Thoracoamniotic Shunting Versus Expectant Management

Prenatal Diagnosis, EarlyView.
ABSTRACT Objective Describe prenatal imaging characteristics, perinatal and postnatal outcomes in fetuses with isolated macrocystic congenital pulmonary airway malformations (CPAM) undergoing thoracoamniotic shunting (TAS) and expectant management. Methods Retrospective cohort study of 123 fetuses with isolated macrocystic CPAM managed at the Ontario ...
Laurence Sophie Carmant, Alexandria Kelly, SeungWoo Lee, Vesna Sokol Karadjole, Greg Ryan, Tim Van Mieghem, Prakesh S. Shah, Anna Otvodenko, Priscilla P. L. Chiu, Nimrah Abbasi   +9 more
wiley   +1 more source

Static hot-fire testing of a green hybrid rocket engine [PDF]

, 2014
This paper presents the conduct of the hot-fire testing for a green hybrid rocket engine. The hybrid rocket engine consists of liquid nitrous oxide (N2O) as the oxidizer, with the stearic acid as the solid fuel and the incorporation of carbon nanotube ...
Abidin, Razali, Ahmad, Mohamed Tarmizi, Jagannathan, Anudiipnath, Saniman, Muhammad Nur Farhan, Zhahir, Amzari   +4 more
core   +1 more source

Effect of Varying Design Options on the Transient Behavior of a Hybrid Rocket Motor

Journal of Aerospace Technology and Management, 2014
Hybrid rockets provide compelling features for use in atmospheric and space rocket propulsion. One of the prominent applications of hybrid rockets which foster on its characteristics is the propulsion of micro air launch vehicles. In this paper, a set of
Raed Kafafy, Muhammad Hanafi Azami, Moumen Idres   +2 more
doaj  

Low-Frequency Feed-System-Coupled Combustion Instability in Hybrid Rocket Motors

Journal of Thermal Science and Technology, 2013
The low-frequency unstable combustion of hybrid rocket motors was investigated using the transfer function of the full thermal-combustion-gasdynamic coupled system that was coupled with a liquid oxidizer feed system.
Takakazu MORITA, Saburo YUASA, Koki KITAGAWA, Toru SHIMADA, Shigeru YAMAGUCHI   +4 more
doaj   +1 more source

Comparison of Optimization Techniques and Objective Functions Using Gas Generator and Staged Combustion LPRE Cycles

Applied Sciences, 2022
This paper compares various optimization techniques and objective functions to obtain optimum rocket engine performances. This research proposes a modular optimization framework that provides an optimum design for Gas Generator (GG) and Staged Combustion
Suniya Sadullah Khan, Ihtzaz Qamar, Muhammad Umer Sohail, Raees Fida Swati, Muhammad Azeem Ahmad, Saad Riffat Qureshi   +5 more
doaj   +1 more source

Screening Surface Modifications to Benzene to Improve Solubility in Hydroxyl‐Terminated Polybutadiene (HTPB)—A DFT Demonstration

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT The objective of this paper is to demonstrate the advantage of computationally pre‐screening surface‐modifying material candidates, using density functional theory (DFT), to inform experimental synthesis and formulation efforts. This demonstration focuses on improving the solubility of benzene‐based materials in hydroxyl‐terminated ...
Samantha E. Knoth
wiley   +1 more source

System Design and Launch of a Hybrid Rocket with a Star-Fractal Swirl Fuel Grain Toward an Altitude of 15 km

Applied Sciences
To achieve low-cost and on-demand launches of microsatellites, the authors have been researching and developing a micro hybrid rocket since 2014. In 2018, a ballistic launch experiment was performed using the developed hybrid rocket, where it reached an ...
Atsushi Takano, Keita Yoshino, Yuki Fukushima, Ryuta Kitamura, Yuki Funami, Kenichi Takahashi, Akiyo Takahashi, Yoshihiko Kunihiro, Makoto Miyake, Takuma Masai, Shizuo Uemura   +10 more
doaj   +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

Review of Alternative Sustainable Fuels for Hybrid Rocket Propulsion

Aerospace, 2023
Hybrid rockets using specific oxidizer–fuel combinations are considered a green alternative to current propulsion systems, as they do not release very toxic or polluting exhausts, but only much less harmful substances such as carbon monoxide/dioxide and ...
Francesco Barato
doaj   +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