Results 31 to 40 of about 252 (179)
Understanding the temperature variability of past interglacial cycles is essential to predict future climates. We present a new summer temperature reconstruction, based on the subfossil chironomid record from a small palaeolake adjacent to the Middle Palaeolithic site of Lichtenberg, northern Germany. The record spans from the Saalian late glacial over
Sonja Rigterink +10 more
wiley +1 more source
Rock Breaking Analysis and Process Parameter Optimization of Pneumatic DTH Hammer Bit
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 +5 more
doaj
Impact Dynamics Prediction of a Rotary-Percussive Ultrasonic Drill With a Free Mass
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 +5 more
doaj +1 more source
Palynological records are central to the biostratigraphic subdivision of the Late Pleistocene in central Europe. Yet many interglacial and interstadial phases—such as the Eemian, Brörup and Odderade—remain only poorly constrained in time due to limited numerical dating.
Michael Hein +19 more
wiley +1 more source
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 +4 more
wiley +1 more source
Study on ROP Enhancement of Composite Percussive Drilling in Deep Tight Shale
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 +5 more
doaj +1 more source
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 +6 more
wiley +1 more source
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 +12 more
doaj +1 more source
ABSTRACT Temperate lake ecosystems undergo seasonal shifts that disproportionately alter the availability of suitable habitat for fishes of different thermal guilds. While many studies have investigated fish habitat use patterns, few have estimated the degree to which fish species overlap in space across seasons from a three‐dimensional perspective ...
Ian A. Richter +3 more
wiley +1 more source
Impacted Bones: Can Extant Primates Help Identify Tool Use in Early Hominins?
ABSTRACT Despite recent advances pushing back the earliest record of tool use, how and when it first emerged in hominins, and the extent to which it featured amongst the numerous co‐existing species, remain critical questions in paleoanthropology. In addition to analyzing fossils and lithic toolkits, novel strides in understanding this might be made by
Rachel M. Hurwitz +3 more
wiley +1 more source

