Results 21 to 30 of about 1,123,828 (350)
Frontiers in Earth Science, 2023 The rock properties are related to the stress environment and dynamic disturbance during construction, and the testing-while-drilling-technique was used for evaluation of rock properties.
Hua Tang +7 more
doaj +1 more source
Meitan kexue jishu, 2023 With the gradual increase in the depth of coal resource extraction in our country, geological conditions and surrounding rock environment are becoming increasingly complex.
Songyong LIU +4 more
doaj +1 more source
A parametric study for the design of an optimized ultrasonic-percussive planetary drill tool [PDF]
, 2016 Traditional rotary drilling for planetary rock sampling, in situ analysis, and sample return are challenging because the axial force and holding torque requirements are not necessarily compatible with lightweight spacecraft architectures in low-gravity ...
Harkness, Patrick +4 more
core +1 more source
British Educational Research Journal, EarlyView., 2023 Abstract Children's relationship with time in preschools is an under‐researched area. Young children rarely know how to measure time using a clock, but their experiences of time may contribute to understanding children's well‐being and debates about quality in preschools.
Kristín Dýrfjörð +3 more
wiley +1 more source
A study of the application of turbine coring drilling technology to hot dry rock drilling
Shuiwen dizhi gongcheng dizhi, 2021 Exploration of hot dry rock in China has just started. In order to accurately evaluate the amount of hot dry rock geothermal resources in China, high-quality hot dry rock drilling cores are needed.
Xianfeng TAN +5 more
doaj +1 more source
High Voltage Electric Pulse Drilling: A Study of Variables through Simulation and Experimental Tests
Energies, 2023 With the deepening of drilling depth, the difficulty of drilling engineering increases gradually due to the complex geological conditions. The traditional mechanical drilling method shows the problems of high energy consumption, low efficiency, long ...
Qingyu Zhang +6 more
doaj +1 more source
Prediction Model of Drilling Performance for Percussive Rock Drilling Tool
Advance in Civil Engineering, 2020 This study suggests a method for quantitatively estimating the drilling performance of the down-the-hole (DTH) hammer during percussive drilling of rock surfaces. A pneumatic dynamic model of the DTH hammer was developed that considers the mass flow rate
Dae-ji Kim +6 more
semanticscholar +1 more source
Modeling pellet impact drilling process [PDF]
, 1999 The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate
Kovalev, Artem Vladimirovich +3 more
core +2 more sources
The rotational motion simulation of AIST small spacecraft prototype based on current values and on a hardware-software stand [PDF]
E3S Web of Conferences, 2023 Improving the quality and volume of drilling is the main condition for advancing the growth of reserves of raw materials of the national economy and industry. Rock-breaking tools are the main and busiest part of drilling equipment.
Khnyryova Ekaterina
doaj +1 more source
Power consumption of rock decomposition process during diamond core drilling using pulse flushing [PDF]
, 2018 Purpose. To study the impact of pulse flushing on the power consumption of rock decomposition during diamond core drilling. Methods. Theoretical analysis, processing of the obtained experimental data. Findings. The decrease in power consumption of rock
Dreus, A, Kozhevnykov, A
core +1 more source