Towards Structured PLIF Excitation for Probing Harsh Environments

Magnetic fields, with a magnitude comparable with that of the earth (10−4 tesla), affect trajectories of electrons and hence gain and collection efficiency. The inclusion of a high-permeability shield usually offers sufficient protection. Photomultiplier (PMT) performance is affected by electric field gradients generated by the proximity of a metal housing. The design criteria of such housings are discussed. Strong magnetic fields of the order of a tesla require special devices. Operation in harsh environments such as those encountered in oil well logging requires performance at high temperature (200 °C) and in situations of high shock and vibration expressed in terms of power spectral density. Rugged PMTs can meet all these requirements. Applications at cryogenic temperatures, such as liquid argon, can also be met with special PMTs.

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Model-Based Slippage Estimation to Enhance Planetary Rover Localization with Wheel Odometry

Applied Sciences ◽

10.3390/app11125490 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5490

Author(s):

Anna Maria Gargiulo ◽

Ivan di Stefano ◽

Antonio Genova

Keyword(s):

Inertial Measurement Unit ◽

Correction Method ◽

Harsh Environments ◽

Measurement Unit ◽

Planetary Rovers ◽

Model Based ◽

Accurate Knowledge ◽

And Control ◽

Wheeled Vehicles ◽

Rover Localization

The exploration of planetary surfaces with unmanned wheeled vehicles will require sophisticated software for guidance, navigation and control. Future missions will be designed to study harsh environments that are characterized by rough terrains and extreme conditions. An accurate knowledge of the trajectory of planetary rovers is fundamental to accomplish the scientific goals of these missions. This paper presents a method to improve rover localization through the processing of wheel odometry (WO) and inertial measurement unit (IMU) data only. By accurately defining the dynamic model of both a rover’s wheels and the terrain, we provide a model-based estimate of the wheel slippage to correct the WO measurements. Numerical simulations are carried out to better understand the evolution of the rover’s trajectory across different terrain types and to determine the benefits of the proposed WO correction method.

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Fragility assessment approach of deepwater drilling risers subject to harsh environments using Bayesian regularization artificial neural network

Ocean Engineering ◽

10.1016/j.oceaneng.2021.108793 ◽

2021 ◽

Vol 225 ◽

pp. 108793

Author(s):

Nan Zhang ◽

Yuanjiang Chang ◽

Jihao Shi ◽

Guoming Chen ◽

Shenyan Zhang ◽

...

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Harsh Environments ◽

Bayesian Regularization ◽

Deepwater Drilling ◽

Assessment Approach ◽

Artificial Neural

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A perspective on corrosion of multi-principal element alloys

npj Materials Degradation ◽

10.1038/s41529-021-00163-8 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

N. Birbilis ◽

S. Choudhary ◽

J. R. Scully ◽

M. L. Taheri

Keyword(s):

Physical Properties ◽

High Resistance ◽

Metallic Alloys ◽

Harsh Environments ◽

Principal Element ◽

Corrosion Resistant ◽

Advanced Technologies ◽

Recent Activity ◽

Engineered Systems ◽

Corrosion And Oxidation

AbstractMetallic alloys are critical to essentially all advanced technologies and engineered systems. The well-documented impact of corrosion (and oxidation) of alloys, remains a significant industrial and economic challenge, year on year. Recent activity in the field of metallurgy has revealed a class of metallic alloys, termed multi principal element alloys (MPEAs) that present unique physical properties. Such MPEAs have in many instances also demonstrated a high resistance to corrosion – which may permit the broader use of MPEAs as corrosion resistant alloys (CRAs) in harsh environments. Herein, the progress in MPEA research to date, along with prospects and challenges, are concisely reviewed—with potential future lines of research elaborated.

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