Results 111 to 120 of about 14,840,273 (340)
Optimization of Hydraulic Structure of Rotary Cutting PDC Bit
Shiyou jixie, 2020 Few researches have been conducted on the hydraulic structure optimization design of rotary cutting PDC bit. Standard k-ε model and discrete phase model (DPM) are used to simulate the bottom hole flow field of rotary cutting PDC bit and optimize the ...
Cao Yang, Zhang Boyu
doaj
Influence of mouldboard ploughing and shallow tillage on soil physical properties and crop performance [PDF]
, 2012 This study was conducted in spring 2011 in a long-term field experiment with the objective of assessing the effect of shallow tillage and mouldboard ploughing on some soil physical properties and crop performance.
Parvin, Nargish
core +1 more source
Rapid Fabrication of Self‐Propelled and Steerable Magnetic Microcatheters for Precision Medicine
Advanced Materials, EarlyView.A rapid Joule heating fabrication method for the production of self‐propelling, adaptive microcatheters, with tunable stiffness and integrated microfluidic channels is presented. Demonstrated through three microrobotic designs, including a steerable guiding catheter, an untethered wave‐crawling TubeBot, and a distal‐end propelled microcatheter, it was ...
Zhi Chen +5 more
wiley +1 more source
Study on Flow Field Characteristics of Rotary Cutting PDC Bit Based on DPM Model
Shiyou jixie, 2021 In order to solve the problems of rotary cutting PDC bit such as uneven distribution of hydraulic energy, easy deposition of cuttings, chaotic flow traces and eddy current in returning area, the discrete phase particle model in numerical simulation was ...
Li Jin +3 more
doaj
Advanced Materials, EarlyView.This study reports the fabrication of MRI‐compatible elastomeric micro‐balloons via a multi‐step bubble casting process, where the monolithic elastomeric wall is selectively stiffened for reversible and controlled inflation and elasticity, depending on the target vessels for graded occlusion of cerebral arteries.
Jong Bin Kim +10 more
wiley +1 more source
Research on ReelWell Drilling Reverse Jet Technology and Tools
Shiyou jixie, 2019 ReelWell drilling technology is based on double-walled drill pipe. The drilling fluid flows into the drill bit from the double-walled drill pipe annulus, and then carries the cuttings and returns to the ground through the inner drill pipe to realize the ...
Huang Tao +4 more
doaj
An approach to a field drainage problem by laboratory examination of selected properties of undisturbed soil cores : thesis presented at Massey University of Manawatu in part fulfilment of the requirements for the degree of Master of Agricutural Science [PDF]
, 1964 For many years, soil drainage investigators, from a practical view point, have had to content themselves with expert appraisal of certain direct and indirect soil and environmental characteristics in order to ascertain the cause of a particular drainage ...
Baker, Christopher John
core
Advanced Materials, EarlyView.An Aloe‐pinspired droplet electricity generator (A‐DEG) overcomes the limited energy collection zone of conventional DEGs by guiding impact droplets through a channeling midrib and artificial cuticle. The channeling midrib induces uni‐directional droplet spreading, while the artificial cuticle on the midrib further reinforces this behavior through its ...
Gibeom Lee +8 more
wiley +1 more source
Modification of Hydraulic Structure of ø660.4 mm Roller Cone Bit and Field Test
Shiyou jixie, 2017 The existing roller cone bits have the issues of poor bottomhole and bit hydraulic cleaning conditions and slow ROP. In view of this, based on the principle of hydraulic structure design of the roller cone bit, a new type of ?660.4 mm roller cone bit ...
Wu Xueping, Li Shuliang
doaj
Numerical simulation of bottomhole flow field of PDC bit in horizontal well
Jin'gangshi yu moliao moju gongchengObjectives: Horizontal wells can effectively improve the economic benefits of shale oil and gas development. However, as the horizontal section extends, the rock debris transport efficiency of the PDC drill bit gradually decreases, which can lead to bit ...
Sai LI +4 more
doaj +1 more source