Results 41 to 50 of about 61,329 (314)

From disorientation to preparedness: Information practices as scaffolding in acute crises

Journal of the Association for Information Science and Technology, EarlyView.
Abstract This qualitative study examines how adults in Israel enacted information practices during an acute national crisis. Using the information transitions framework, we investigate how concrete practices emerge and evolve across three stages: understanding, negotiating, and resolving. Semi‐structured Zoom interviews with 18 adults were analyzed via
Lilach Alon, Tali Malinoff, Inbar Levkovich   +2 more
wiley   +1 more source

Young people's occupational aspirations beyond the aspiration discourse: A sociocultural perspective

British Educational Research Journal, EarlyView.
Abstract Young people's aspirations have been the focus of many educational, sociological and psychological studies. This paper argues, firstly, that the concept of aspirations holds greater generative potential than suggested by the policy‐oriented ‘aspiration discourse’.
Jelena Popov
wiley   +1 more source

Assessing the Metrological Reliability of Static Firing Tests of Rocket Motors Through the Evaluation of Thrust and Total Impulse Measurement Uncertainty

Applied Sciences
A solid propellant rocket motor is a propulsion system used in missiles and rockets that burns a propellant, typically composed of a mixture of fuel and an oxidizer, to generate the thrust necessary to propel the vehicle.
Fernando de Paula Leite Castor, Carlos Roberto Hall Barbosa, Elcio Cruz de Oliveira   +2 more
doaj   +1 more source

Three‐Dimensional Highly Thermally Conductive Graphene Blocks by Multiscale Blending and Multistage Pressure Induction

Carbon Energy, EarlyView.
An expandable‐thickness graphene block (GPB) with high thermal conductivity synthesized through multiscale blending and multistage pressure induction (MBP) achieves a record thickness of 12.1 mm, which is more than 10 times that of existing graphene materials. The maximum thermal diffusion ability of GPB‐MBP reaches 6.3 W/K, which offers a new approach
Liyu Zhang, Haitao Hu, Xuan Li, Haihan Xu, Xiaoying Gao, Ruishi Lin, Yingze Meng, Jiaxin He, Shoujin Chang, Guoliang Ding   +9 more
wiley   +1 more source

Non‐negative Gaussian estimation of variance components in random effects models

Canadian Journal of Statistics, EarlyView.
Abstract When used to estimate variance components (VCs), confidence intervals (CIs) can be truncated at zero, have a point estimate not in the quoted CI, be empty with positive probability, or be all‐inclusive. This is because they have conflicting dual roles, since they are considered to cover the parameter with a specified probability while also ...
André Plante, Michael Plante
wiley   +1 more source

Long-Duration Dynamic Numerical Simulation of Combustion and Flow in Hybrid Rocket Motors Considering Nozzle Erosion

Aerospace
Hybrid rocket motors have great development potential due to their outstanding thrust adjustment flexibility and long-term operation ability. However, nozzle erosion during the motor operation can cause an increase in the throat area of the nozzle, which
Xiangyu Meng, Hui Tian, Xiaoting Niu, Hao Zhu, Jingfei Gao, Guobiao Cai   +5 more
doaj   +1 more source

Modelagem da combustão da dinitramida de amônio por simulação computacional Ammonium dinitramide combustion modeling by computational simulation

Química Nova, 2009
In this work, the combustion process of ammonium dinitramide, ADN, has been modeled in two different situations: decomposition in open environment, with abundant air and decomposition in a rocket motor internal environmental conditions.
Rene Francisco Boschi Gonçalves, José Atílio Fritz Fidel Rocco, Koshun Iha, Francisco Bolivar Correto Machado   +3 more
doaj   +1 more source

Solid propellant rocket motor [PDF]

, 1973
The characteristics of a solid propellant rocket engine with a controlled rate of thrust buildup to a desired thrust level are discussed. The engine uses a regressive burning controlled flow solid propellant igniter and a progressive burning main solid ...
Behm, J. W., Dowler, W. L., Shafer, J. I., Strand, L. D.   +3 more
core   +1 more source

Plasmakristall‐4 Experiment: 10 Years of Operation in Orbit

Contributions to Plasma Physics, EarlyView.
ABSTRACT Plasmakristall‐4 (PK‐4) is a microgravity complex plasma laboratory operated for 10 years on board the International Space Station. Its main purpose is the particle‐resolved investigation of generic condensed matter phenomena using strongly coupled suspensions of microparticles immersed in low‐pressure gas‐discharge plasmas.
M. Pustylnik, H. M. Thomas, M. Kretschmer, M. Thoma   +3 more
wiley   +1 more source

Stopping Power of Electron Liquid for Slow Quantum Projectiles

Contributions to Plasma Physics, EarlyView.
ABSTRACT We revisit the problem of the deceleration of a charge moving in a medium. In the low‐velocity limit of the projectile, we construct the fully nonlinear (in the charge–target interaction) theory of the stopping power (SP), which goes beyond the classical Ehrenfest dynamics.
Vladimir U. Nazarov, E. K. U. Gross
wiley   +1 more source