Results 41 to 50 of about 236,174 (283)

Simulation of the Drill String Vibration Signal System

open access: yesShiyou jixie, 2015
To understand the signal transmission processes and rules as well as the structure and components of signals inside the drill string,through establishing signal transmission model,a drill string vibration simulation software has been developed based on ...
宋一晨, 吕苗荣, 陆健
doaj  

Mechanical Modelling of Drill‐Strings [PDF]

open access: yesPAMM, 2003
AbstractVibrations in long torsional strings result in spatio‐temporal dynamics. These vibrations disturb the accuracy of the drilling process and may cause damage due to fatigue. The high costs of drillings are the main motivation for the suppression of vibrations of the drill–string. In this paper a model for the drill string is proposed. In order to
E. Kreuzer, H. Struck
openaire   +1 more source

Predicting the Reactivity of Acyclic Silylenes and Germylenes in Hydrogen Activation Using Machine Learning

open access: yesAdvanced Science, EarlyView.
Statistical models for the prediction of the energy profile of H2 activation by silylenes and germylenes were developed. A simple model based on increments of the elements in α‐position enabled robust energy prediction, extrapolation to new structures, and transferability to new tetrylenes and substrates.
Michelle Kleinhaus   +4 more
wiley   +1 more source

Development of Similarity Theory-based Horizontal Well Drill String Test Apparatus

open access: yesShiyou jixie, 2016
In order to conduct research on dynamic properties of drill string in the horizontal well,a horizontal well drill string test apparatus is developed based on parameter correspondence between test model and site prototype.The parameter correspondence is ...
Ren Fushen   +3 more
doaj  

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

Two‐Dimensional Flash Memory: Materials, Interfaces, and Storage–Computing Convergence

open access: yesAdvanced Science, EarlyView.
We systematically summarize recent advances in 2D flash memory, highlighting how interface and material engineering can overcome the conventional trade‐offs among speed, power consumption, and reliability in silicon‐based flash, and outlining its potential for high‐performance memory and in‐memory computing applications.
Zhiyuan Wang   +10 more
wiley   +1 more source

Investigation of kinetic energy dissipation characteristics of the drill string during rotary drilling in underground coal mines

open access: yesGeomechanics and Geophysics for Geo-Energy and Geo-Resources
In underground coal mine rotary drilling, rock-breaking energy is transmitted from the drill string to the drill bit. Nonlinear vibrations of the drill string within the borehole result in kinetic energy dissipation.
Shuhan Shi   +7 more
doaj   +1 more source

Concord String Quartet [PDF]

open access: yes, 2008
String Quartet in E Major, Op. 125, No. 2, D.353, Franz Schubert (1797-1828) -- String Quartet (1974), Ellsworth Milburn (1938-) -- String Quartet in A Minor, Op.

core  

Aspects of Topological String Theory [PDF]

open access: yes, 2008
Two aspects of the topological string and its applications are considered in this thesis. Firstly, non-perturbative contributions to the OSV conjecture relating four-dimensional extremal black holes and the closed topological string partition function ...
Cook, Paul Langabi Hogan
core   +1 more source

Vine‐Inspired Soft Robotics: Materials, Actuations, and Emerging Applications

open access: yesAdvanced Science, EarlyView.
Vine‐inspired robots grow from the tip, enabling navigation through confined spaces with minimal disturbance. This Review summarizes material and actuation strategies for vine‐inspired growth, key functions including steering, retraction, attachment, branching, and variable stiffness, and emerging applications spanning medical intervention, confined ...
Jiahao Wu   +7 more
wiley   +1 more source

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