Results 41 to 50 of about 168,341 (157)

A bifacial paradise—The site of Ochtmissen, Germany, and its lithic assemblage in the context of the last glacial (early MIS 4) in the north‐central European Lowland

Boreas, EarlyView.
The Palaeolithic site of Ochtmissen (Lower Saxony, Germany) was excavated in fluvial terrace deposits during the winter of 1993/1994. The current study presents, for the first time, a thorough analysis of the lithic assemblage, encompassing its primary technological and typological characteristics, as well as the type and age of the fluvial deposits ...
Gianpiero Di Maida, Jutta Winsemann, Markus Fuchs, Niklas von Soest, Thomas Terberger   +4 more
wiley   +1 more source

Microcomputer simulation of percussive drilling

, 1985
Churn drilling, down-the-hole drilling, hammer drilling, and related drilling and breaking processes are simulated by means of a microcomputer. The simulation programs are written in Apple Pascal for the Apple II family of computers.
Lundberg, Bengt,
core   +1 more source

Study on ROP Enhancement of Composite Percussive Drilling in Deep Tight Shale

Xinjiang shiyou tianranqi
To address the challenges of high compressive strength，low drillability，and extended drilling time in the deep tight shale of the Mabei Fengcheng Formation，an experimental study on drilling parameter optimization for axial-torsional coupled percussive ...
MU Zongjie, QIU Zilun, FANG Yan, YANG Zhehua, SHI Jiangang, ZHANG Panpan   +5 more
doaj   +1 more source

Rock Breaking Analysis and Process Parameter Optimization of Pneumatic DTH Hammer Bit

Shiyou jixie, 2022
In order to improve the rock-breaking efficiency and penetration ability of pneumatic DTH hammer in hard strata, based on the theory of nonlinear contact dynamics, the ABAQUS software was used to build a piston-pneumatic DTH hammer bit-rock(granite ...
Wang Shenglin, Wei Qinwen, Liu Chengjun, Deng Yinjiang, Zhang Shiming, Xiao Xinyuan   +5 more
doaj  

Impact Dynamics Prediction of a Rotary-Percussive Ultrasonic Drill With a Free Mass

IEEE Access, 2018
The rotary-percussive ultrasonic drill (RPUD) employs vibrations on two sides of a piezoelectric stack to drive a drill tool to achieve simultaneous rotary-percussive motion.
Deen Bai, Qiquan Quan, Yinchao Wang, He Li, Pengyue Zhao, Zongquan Deng   +5 more
doaj   +1 more source

Stem Cells From Dental Pulp, Periodontal Tissues, and Other Oral Sources: Biological Concepts and Regenerative Potential

Journal of Periodontal Research, EarlyView.
A graphical abstract recapping the different sources of dental, periodontal, and other oral‐derived mesenchymal stromal cells (MSCs) and their regenerative mechanisms and potentials. The review's article findings bridge fundamental biological science with translational advances, highlighting the significance of MSCs in craniofacial regenerative ...
Karim M. Fawzy El‐Sayed, Sara El Moshy, Israa Ahmed Radwan, Dina Rady, Aiah A. El‐Rashidy, Marwa M. S. Abbass, Christof E. Dörfer   +6 more
wiley   +1 more source

Design, test, and verification of in-situ condition preserved coring and analysis system in lunar-based simulation environment

International Journal of Mining Science and Technology
The lunar surface and its deep layers contain abundant resources and valuable information resources, the exploration and exploitation of which are important for the sustainable development of the human economy and society.
Haichun Hao, Mingzhong Gao, Yan Wu, Zheng Gao, Yongcheng Li, Xuemin Zhou, Peng Chu, Xuan Wang, Jiahua Li, Lang Zhou, Jie Song, Tianxiang Ao, Yikun Yang   +12 more
doaj   +1 more source

WHAT ONCE WAS SHALL BE AGAIN: PALAEOLITHIC BIFACES AT THE NEOLITHIC SITE OF GIV'AT RABI EAST

Oxford Journal of Archaeology, EarlyView.
Summary Giv'at Rabi East is a Pre‐Pottery Neolithic B site located in northern Israel, interpreted as a flint workshop. One area has been spatially identified as a ‘biface locality’; it is characterized by the presence of finished axes and preforms alongside débitage. Interestingly, Acheulean bifaces have also been recovered from this area.
Ella Assaf
wiley   +1 more source

Clinical and Radiographic Outcomes Following Unintentional Extrusion of Cold Ceramic: A Case Series of Three Patients

Clinical Case Reports, Volume 14, Issue 10, October 2026.
ABSTRACT In three patients with unintentional extrusion of cold ceramic beyond the root apex, favorable clinical and radiographic outcomes were observed over 2–4 years. These descriptive observations do not establish the safety or biological effects of extruded material, but support careful clinical and radiographic follow‐up when patients remain ...
Jalil Modaresi, Maaz Anwer Memon, Mojtaba Mehrabanian   +2 more
wiley   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

Journal of Field Robotics, Volume 43, Issue 7, Page 4475-4514, October 2026.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang, Hao Zhou, Dalin Zhou, Zhaojie Ju   +3 more
wiley   +1 more source