Results 61 to 70 of about 285 (198)

In Situ Acoustic Monitoring of Focused Femtosecond Pulse Duration in Air

Laser &Photonics Reviews, EarlyView.
Air‐breakdown acoustics at the laser focus is used to determine femtosecond pulse duration with a simple USB microphone. By chirp‐tuning and compressing 1030 nm pulses from 241 to 50 fs, the acoustic amplitude scales inversely proportional to the square root of the pulse duration, enabling in situ readout over 50 fs–5 ps—crucial for precise pulse ...
Indrė Meškėlaitė, Hsin‐Hui Huang, Haoran Mu, Nguyen Hoai An Le, Tomas Katkus, Edvinas Aleksandravičius, Gabrielius Kontenis, Domas Paipulas, Saulius Juodkazis, Darius Gailevičius   +9 more
wiley   +1 more source

Analysis of Aerodynamic Characteristics of Rotating Detonation Turbine Based on Proper Orthogonal Decomposition Method

Aerospace
The unsteady interactions in rotating detonation turbine engines (RDTE) remain poorly understood. To address this, a 2D numerical model integrating a rotating detonation combustor (RDC) with a first-stage turbine is established to analyze flow structures
Meiting Ling, Ting Zhao, Wenguo Luo, Jianfeng Zhu, Yancheng You   +4 more
doaj   +1 more source

Monitoring shallow geothermal aquifers with active‐source distributed acoustic sensing: A prognostic feasibility study on the University of Leeds Geothermal Campus

Near Surface Geophysics, EarlyView.
Abstract The United Kingdom's shallow aquifers offer significant but underdeveloped geothermal energy resource. Seismic methods can help address this by improving the understanding of aquifer heterogeneity and potentially allowing long‐term monitoring of thermal plumes.
Adam D. Booth, Roger A. Clark, Andy Nowacki, Ravi Myanger, Joseph Kelly, Sjoerd de Ridder, Arka Dyuti Sarkar, Fleur Loveridge, Richard Collier, Emma Bramham, David Healy   +10 more
wiley   +1 more source

Design and Development of a Modular Ballistic Pendulum for High‐Impulse Measurement in Contact and Near‐Field Explosive Loading

Propellants, Explosives, Pyrotechnics, EarlyView.
ABSTRACT Measuring impulse from explosive charges in contact and near‐field configurations presents practical challenges due to wide variation in impulse magnitude. Ballistic pendula are widely used for impulse measurement, but many existing designs are limited to narrow operating envelopes or are poorly suited to repeated contact testing and tamped ...
R. Alford, R. Hazael, R. Critchley, L. Humphreys   +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

Forecast‐Error Diagnostics in Neural Weather Models

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Deep learning weather prediction models enable efficient forecast‐error diagnostics through auto‐differentiation and low computational cost. We apply grid‐point relaxation and gradient‐based error sensitivity to identify key forecast‐error sources. Results show that medium‐range forecasts in the midlatitudes benefit most from relaxing the stratosphere ...
Uroš Perkan, Gregor Skok, Žiga Zaplotnik   +2 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

Linear System Identification and Control of a Low‐Cost High‐Performance Omnidirectional Marine Surface Vehicle for Swarming Applications

Journal of Field Robotics, EarlyView.
ABSTRACT Marine operations traditionally rely on human intervention, a costly and disruptive method. Autonomous surface vehicles (ASVs) offer a powerful alternative, capable of operating autonomously, for extended periods, and with various sensors for various missions.
Ayman El Qemmah, Gianni Cario, Alessandro Casavola, Marco Lupia, Francesco Tedesco   +4 more
wiley   +1 more source

Effects of Annular Combustor Width on the Ethylene-Air Continuous Rotating Detonation

International Journal of Aerospace Engineering, 2020
The realization and stable operation of Continuous Rotating Detonation (CRD) in the annular combustor fueled by hydrocarbon-air are still challenging.
Weijie Fan, Shijie Liu, Jin Zhou, Haoyang Peng, Siyuan Huang   +4 more
doaj   +1 more source

Bridging the Late Antique Gap in Northwest Arabia: New Archaeological Evidence on the Occupation of Wādī al‐Qurā (al‐ʿUlā [AlUla], Saudi Arabia) Between the Third and Seventh Centuries CE

Arabian Archaeology and Epigraphy, EarlyView.
ABSTRACT In 2019, the Dadan Archaeological Project (CNRS/RCU/AFALULA) identified a Late Antique village 1 km south of ancient Dadan in the al‐ʿUlā valley (northwest Saudi Arabia). Three excavation seasons at this site (2021–2023) have uncovered a massive building constructed in the late third or early fourth cent.
Jérôme Rohmer, Abdulrahman Alsuhaibani, Charlène Bouchaud, Elora Chambraud, Vladimir Dabrowski, Hatem Djerbi, Fabien Lesguer, Hervé Monchot, Paul Picavet, Louise Purdue, Bertrand Riba, Shadi Shabo   +11 more
wiley   +1 more source