Results 91 to 100 of about 3,292 (246)

Dynamic Model and Stick-slip Reduction Characteristics of a New Torsional Vibration Tool

工程科学与技术, 2020
In the process of oil and gas exploitation, with the increase of drilling depth, the rock hardness is increased, and the downhole friction resistance is larger, the drill string system is prone to stick-slip vibration, which may lead to premature ...
Jialin TIAN, Hongzhi HE, Lin YANG, Yinglin YANG, Qianjin CHENG, Genyin LI, Shuhui HU   +6 more
doaj  

A modal method for the simulation of nonlinear dynamical systems with application to bowed musical intruments [PDF]

, 2008
Bowed instruments are among the most exciting sound sources in the musical world, mostly because of the expressivity they allow to a musician or the variety of sounds they can generate. From the physical point of view, the complex nature of the nonlinear
Inacio, Octávio José Patrício Fernandes Inácio
core  

Downhole Vibration Measurement, Monitoring, and Modeling Reveal Stick/Slip as a Primary Cause of PDC-Bit Damage in Today [PDF]

, 2010
Since backward whirl was discovered as a severe cause of PDC bit failure, our industry has made great strides toward creating whirl-resistant bits and operating practices. But is whirl still the major cause of PDC bit damage in today's applications? This
Olivier J. Hoffmann, Christian Herbig, L. W. Ledgerwood, Carmel El Hakam, Reed W. Spencer, Jayesh R. Jain   +5 more
core   +1 more source

Deciphering Intricacies in Directional CO2 Conversion From Electrolysis to CO2 Batteries

Advanced Energy Materials, EarlyView.
This review will delve into the inherent connections and distinctions of CO2‐directed conversion in ECO2RR and CO2 batteries, in terms of product types, catalyst selection, catalytic mechanisms, and electrochemical performances, while proposing a benchmarking framework for the evaluation of CO2 batteries and innovative CO2 battery configurations for ...
Changfan Xu, Huaping Zhao, Lizhuang Chen, Weidong Shi, Guosheng Shao, Yong Lei   +5 more
wiley   +1 more source

Redirecting Excited‐State Proton Transfer Through Supramolecular Polymerization in Nanoconfinement

Angewandte Chemie, EarlyView.
Supramolecular confinement redirects the excited‐state proton transfer pathway of an amphoteric emitter. In water, the molecule undergoes ESPD, whereas co‐assembly with γ‐cyclodextrin forms nanotubes that template slip‐stacked emitter pairs and enable ESIMPT. Structural and photophysical characterization of the assemblies shows that the preorganization
Luis C. Pantaleone, Robert Hutchings, Bente Reus, Jacopo Martinelli, Alessia Lasorsa, Patrick C. A. van der Wel, Marc C. A. Stuart, Wesley R. Browne, Tibor Kudernac   +8 more
wiley   +2 more sources

Downhole vibration causing a drill collar failure and solutions

Natural Gas Industry B, 2017
In large borehole drilling of some blocks or formations, due to serious downhole vibration, fatigue failure of a drill collar occurs frequently and most washouts and fractures are in thread root.
Quanta Zhu, Zongming Zou, Bing Huang, Linhu Ma, Jiaxiang Xia   +4 more
doaj   +1 more source

Analytical approximations for stick-slip vibration amplitudes [PDF]

, 2003
The classical "mass-on-moving-belt" model for describing friction-induced vibrations is considered, with a friction law describing friction forces that first decreases and then increases smoothly with relative interface speed.
Thomsen, Jon Juel, Fidlin, A.
core  

Analysis of Stick-Slip Characteristics of an Inclined Frictional Contact System [PDF]

For the purpose of investigating the stick-slip characteristics of the inclined frictional contact interface, a three-dimensional numerical model of a slider-substrate inclined frictional contact system is constructed by using the finite element method ...
Liu, Shiyu, Wang, Zhiqiang, Lei, Zhenyu
core   +2 more sources

Stick-Slip Behavior of Torque Converter Clutch [PDF]

, 2005
Copyright © 2005 SAE International The chief objective of this paper is to study the non-linear behavior of torque converter clutch within the context of an automotive drivetrain.
Chengwu Duan, Rajendra Singh
core   +1 more source

Smart Flexible Tactile Sensors: Recent Progress in Device Designs, Intelligent Algorithms, and Multidisciplinary Applications

Advanced Intelligent Discovery, EarlyView.
Flexible tactile sensors have considerable potential for broad application in healthcare monitoring, human–machine interfaces, and bioinspired robotics. This review explores recent progress in device design, performance optimization, and intelligent applications. It highlights how AI algorithms enhance environmental adaptability and perception accuracy
Siyuan Wang, Ming Dong, Rongrong Bao, Caofeng Pan   +3 more
wiley   +1 more source