Results 31 to 40 of about 194,053 (216)

Numerical Simulation Study on the Rock Breaking Effect of Multiple Axe-Shaped Cutters in Rotary Percussion Drilling

open access: yesShiyou jixie
The compatibility of percussion tools, PDC cutter types and hard rock formations is a key factor in extending the service life of percussion tools and drill bits and achieve the best rock breaking effect, but it has been rarely studied.
Leng Youheng   +4 more
doaj   +3 more sources

Challenges of rock drilling and opportunities from bio-boring

open access: yesBiogeotechnics, 2023
Drilling plays a significant role in the history of human civilization. The exploration of greater depths, extreme environments, or hazardous areas calls for more energy-efficient and high levels of autonomous drilling technologies with reduced cost and ...
Yumeng Zhao, Sheng Dai
doaj   +1 more source

Influence of Mechanical Rotary Percussion Tool on Bit Feed Friction of Horizontal Well

open access: yesShiyou jixie, 2023
Weight-on-bit(WOB)congestion is one of the main factors restricting the penetration rate of sliding drilling in horizontal wells, and the use of vibration friction reduction tools is the most direct and effective way to reduce friction in horizontal ...
Yan Yan   +5 more
doaj  

Micromachining of Invar Foils with GHz, MHz and kHz Femtosecond Burst Modes

open access: yesMicromachines, 2020
In this work, a burst mode laser is used for micromachining of 20 µm–250 µm thick Invar (Fe64/Ni36) foils. Holes were drilled by firing multiple pulses transversely onto the sample without moving the beam (percussion drilling).
Simas Butkus   +4 more
doaj   +1 more source

University Percussion Ensemble, December 11, 1986

open access: yes, 2016
Recorded during a live performance at Dalton Center Recital Hall, Western Michigan University, Kalamazoo, Michigan, December 11, 1986, 9:00 p.m., the 151st concert of the School of Music's 1986-1987 season.Members of the University Percussion Ensemble in
Western Michigan University. Percussion Ensemble
core   +2 more sources

High Efficiency Drilling Methods for Through Beds Hole in Underground Coal Mine

open access: yesMeikuang Anquan, 2020
Considering the drilling efficiency problem encountered by crossing holes in underground coal mine, the paper divided roof and floor rock stratum into three grades in order to facilitate the study of technology in underground coal mine: high hard rock (4≤
DOU Xuqian
doaj   +1 more source

Identification of Impact Frequency for Down-the-Hole Drills Using Motor Current Signature Analysis

open access: yesApplied Sciences, 2023
In rotary-percussion drilling, the impact frequency is a crucial variable that is closely linked to operational factors that determine the efficacy of the drilling process, such as the rate of penetration, bit wear, and rock mass characteristics. Typical
Diego Brito   +4 more
doaj   +1 more source

University Percussion Ensemble, March 21, 1979

open access: yes, 2018
Recorded during a live performance at Oakland Recital Hall, Western Michigan University, Kalamazoo, Michigan, March 21, 1979, program no. 204 of the Department of Music's 1978-1979 season.University Percussion Ensemble, Michael Varner, director ; Roxann ...
Western Michigan University. Percussion Ensemble
core   +2 more sources

Borophene‐based sensing platforms: Pioneering ultrasensitive detection

open access: yesFlexMat, EarlyView.
Schematic Diagram of Performance Optimization Strategies and Sensing Application Characteristics of Two‐Dimensional Boron‐Based Materials in Novel Sensors. Abstract Borophene is an emerging two‐dimensional (2D) material. Since significant breakthroughs were achieved in the experimental synthesis of borophene, the exploration and development of ...
Chi Yuan, Yanpeng Ji, Yi Liu, Guoan Tai
wiley   +1 more source

Structural Design and Test of Mechanical Rotary Percussion Drilling Tool

open access: yesShiyou jixie, 2020
Rotary percussion drilling technology can greatly increase the ROP of hard formations, but for plastic rocks, rock fragmentation is poor. For this reason, this paper proposes a technical plan for mechanical rotary percussion drilling tool prototype ...
Zhang Haiping
doaj  

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