Results 31 to 40 of about 4,494 (274)

Drill-String Dynamics: Reduced-Order Models

open access: yes, 2009
Research efforts are underway to model and study the dynamics of a drill string, and preliminary results are presented in this work. The dynamics of a drill string system has non-smooth characteristics. Moreover, the drill string system dynamics exhibits
Balakumar Balachandran   +2 more
core   +1 more source

Modeling and Analysis of Drill String–Casing Collision under the Influence of Inviscid Fluid Forces

open access: yesApplied Sciences, 2023
The current study aims to study the drill string–casing system operating in an inviscid fluid under imbalanced and rubbing damage types. The Navier–Stokes equations were linearized to establish the hydrodynamic forces surrounding the drill string and ...
Bernard Xavier Tchomeni Kouejou   +2 more
doaj   +1 more source

Drill string rotary speed influence on equivalent circulating density value

open access: yes, 2018
Presented article displays a debate about very complex and still not fully understood issue of drill string rotary speed (DSRS) impact on pressure losses in wellbore annulus, thus Equivalent Circulating Density (ECD) value.
Kiebzak, P.   +5 more
core   +1 more source

Sensing and computational frameworks for improving drill-string dynamics estimation [PDF]

open access: yes, 2021
International audienceIn this paper, we consider the axial motion of a directional multi-sectional drill-string. The drillstring dynamics are represented by a distributed dynamical model (wave equations) coupled with an ordinary differential equation at ...
Auriol, Jean   +2 more
core   +1 more source

Review of Thermally Activated Twisted Coiled Polymer Actuators: A Materials Science Perspective

open access: yesAdvanced Functional Materials, EarlyView.
Thermally activated twisted and coiled polymer actuators (TCPAs) combine lightweight design, large deformation, and scalable fabrication for soft robotic and wearable applications. This review connects polymer structure, processing history, helix geometry, and thermomechanical characterization to actuator performance, highlighting current challenges in
Nadja Schenk   +3 more
wiley   +1 more source

Analysis on Casing Wear Induced by Drill String Whirling during Workover Drill Grinding

open access: yesShiyou jixie, 2021
When the drill string rotates in the wellbore, it will whirl, collide with and rub against casing inwall, resulting in casing wear and reducing wellbore safety.
Cao Yinping   +3 more
doaj  

Translational Considerations for Injectable Biomaterials and Bioscaffolds to Repair and Regenerate Brain Tissue

open access: yesAdvanced Healthcare Materials, EarlyView.
The repair and regeneration of brain tissue faces both biological and technical challenges. Injectable bioscaffolds offer new opportunities to stimulate tissue regrowth in the brain by recruiting neural stem cells. Here, the translational issues are reviewed that need to be address to advance this promising new therapeutic approach from the bench to ...
Michel Modo, Alena Kisel
wiley   +1 more source

Fatigue Analysis of the Drill String According to Multiaxial Stress

open access: yes, 2011
To find out the cause for fatigue failure of a drill string used in oil field drilling, and considering the actual working conditions, axial, radial and circumferential cyclic stresses borne by the drill string in borehole of oil and gas well, fatigue ...
Xiang Hong Lv, Jian Bing Zhang
core   +1 more source

Adaptable Covalent Organic Framework‐Hydrogel Microneedles for Glucose‐Responsive Isoliquiritigenin Delivery in Diabetic Wound Therapy

open access: yesAdvanced Healthcare Materials, EarlyView.
We develop a covalent organic framework‐loaded Traditional Chinese Medicine monomer nanodrug delivery system (ISL@bCOF) via boron‐oxygen bonds, a smart response to glucose for delivering AI‐driven isoliquiritigenin (ISL) targeting ZBP1. This dynamic release mechanism, combined with transdermal delivery technology via potent microneedles, can modulate ...
Menghan Zhou   +9 more
wiley   +1 more source

Beyond Presumptions: Toward Mechanistic Clarity in Metal‐Free Carbon Catalysts for Electrochemical H2O2 Production via Data Science

open access: yesAdvanced Materials, EarlyView.
Metal‐free carbon catalysts enable the sustainable synthesis of hydrogen peroxide via two‐electron oxygen reduction; however, active site complexity continues to hinder reliable interpretation. This review critiques correlation‐based approaches and highlights the importance of orthogonal experimental designs, standardized catalyst passports ...
Dayu Zhu   +3 more
wiley   +1 more source

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