Results 61 to 70 of about 2,421 (246)

Natural Frequency Analysis of a Stepped Drill String in Vertical Oil Wells Subjected to Coupled Axial–Torsional–Lateral Vibrations

open access: yesEnergies
Drilling oil and gas wells is a complex process that requires a combination of several parameters to dig into the ground. Inappropriate drilling parameter settings and reaction forces can lead to unwanted vibrations, which can negatively impact the drill
Mohamed Zinelabidine Doghmane
doaj   +1 more source

Research Progress of Three‐Terminal Perovskite/Silicon Tandem Solar Cells Based on Back‐Contact Silicon

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Perovskite/silicon tandem solar cells offer efficiencies beyond 30%, yet conventional architectures face trade‐offs between optical performance and current matching. Three‐terminal tandems employing silicon back‐contact bottom cells eliminate the current‐matching constraint while minimizing optical losses, offering superior energy yield under real ...
Yunhao Fan   +4 more
wiley   +1 more source

Seismic Performance and Vibration‐Based Damage Identification of Two‐Storey Balloon‐Framed CLT Shear Walls

open access: yesEarthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT While cross‐laminated timber (CLT) is increasingly utilized in lateral force‐resisting systems in mass timber construction, research has predominantly focused on platform‐type construction. Balloon‐type CLT shear wall systems offer distinct structural advantages, notably the elimination of cumulative perpendicular‐to‐grain compression and a ...
Samira Mohammadyzadeh   +3 more
wiley   +1 more source

Flow Characteristics and Response Surface Methodology‐Based Pressure‐Loss Prediction Models for the Reverse Circulation Converter in Double‐Wall Drill Pipes

open access: yesEnergy Science &Engineering, EarlyView.
Flow characteristics and pressure loss mechanisms of a reverse circulation converter in dual‐wall drill pipes are systematically investigated using CFD and response surface methodology. The results reveal the dominant role of inertial dissipation and provide a predictive framework for optimizing converter design and operational parameters. ABSTRACT The
Mingming Geng   +8 more
wiley   +1 more source

Recent advances in multifunctional soft robots: A materials–structures–systems co‐design perspective for synergistic integration

open access: yesFlexMat, EarlyView.
Abstract Soft robots, engineered from highly compliant materials, offer superior adaptability and safety in unstructured environments compared to their rigid counterparts. Recent advancements, fueled by bio‐inspiration and material programmability, have led to the rapid co‐evolution of their core modules: actuation, sensing, protection, energy, and ...
Qiulei Liu   +3 more
wiley   +1 more source

Drought Risk in Mango and Avocado Orchards: Insights Into Plant Water Relations and Irrigation‐Related Agronomic Solutions

open access: yesIrrigation and Drainage, EarlyView.
ABSTRACT Climate change is making water availability more uncertain, with growing consequences for the productivity and long‐term sustainability of tropical and subtropical fruit orchards. Mangifera indica L. and Persea americana Mill. both require large amounts of water to sustain growth and productivity.
Eleonora Cataldo
wiley   +1 more source

An Analytical–Numerical Model for Determining “Drill String–Wellbore” Frictional Interaction Forces

open access: yesEnergies
Currently, drilling of directional oil and gas wells under complex technical-technological and mining-geological conditions requires the use of drill pipes made of various materials.
Michał Bembenek   +7 more
doaj   +1 more source

Nonlinear Model and Qualitative Analysis for Coupled Axial/Torsional Vibrations of Drill String

open access: yesShock and Vibration, 2016
A nonlinear dynamics model and qualitative analysis are presented to study the key effective factors for coupled axial/torsional vibrations of a drill string, which is described as a simplified, equivalent, flexible shell under axial rotation.
Fushen Ren   +4 more
doaj   +1 more source

Deliberate Practice Supervision to Enhance the Effectiveness of Behavioral Activation for Depression: A Case Study

open access: yesJournal of Clinical Psychology, Volume 81, Issue 6, Page 526-537, June 2025.
ABSTRACT Deliberate Practice (DP) is a model of behavioral skill acquisition structured by several key tasks. The past decade has shown a consistent growth in interest in this form of learning for psychotherapy skills, with promising research suggesting DP training is superior to traditional learning methods of psychotherapy. This paper presents a case
Dan Sacks
wiley   +1 more source

Proportional-Derivative Control of Stick-Slip Oscillations in Drill-Strings

open access: yesMATEC Web of Conferences, 2018
Stick-slip oscillation in drill-string is a universal phenomenon in oil and gas drilling. It could lead to the wear of drill bit, even cause catastrophic failure of drill-strings and measurement equipment.
Lin Wei, Liu Yang
doaj   +1 more source

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