Results 31 to 40 of about 285,909 (143)
Archaeometry, EarlyView.ABSTRACT Pinctada margaritifera (black‐lipped pearl oyster) artefacts are ubiquitous in the archaeological record throughout the Pacific and particularly in Polynesia. Despite efforts towards the development of typologies, the lack of microwear and use‐wear studies has prevented the development of technological approaches. We used 20 pearl shell valves
Jemma McGloin +2 more
wiley +1 more source
Flow structure and rock-breaking feature of the self-rotating nozzle for radial jet drilling
Petroleum Science, 2019 For improving the hole-enlarging capability, roundness and rock-breaking efficiency of the nozzle in radial jet drilling, a new structure of self-rotating nozzle was put forward.
Hua-Lin Liao +5 more
doaj +1 more source
Boreas, EarlyView.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
New drilling methods for the conductor casing operations [PDF]
Acta Montanistica Slovaca, 2006 The necessity to apply casing to wells drilled in loose rock strata have recently created conditions for the modernization of old solutions and the development of new drilling technologies. The newest World's design and technological solutions for rotary,
Rafał Wiśniowski
doaj
Rotary - percussion drilling method - historical review and current possibilities of application [PDF]
, 2015 'Faster, deeper, cheaper' -it is not just a slogan, it is a motto of every oil company. The first application of rotary--percussion drilling method in drilling oil wells took place in early 60's of the XX century in the United States.
Korzec, M. +4 more
core +1 more source
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 +4 more
wiley +1 more source
Study on Construction Technology of Rock-socketed Pile Group for Offshore Wind Turbine Generators
Renmin Zhujiang, 2020 This paper simulates and analyzes the driveability of steel pipe pile under complex geological conditions by the GRLWEAP software,and studies the construction technology of integrated rock-socketed pile group based on the statistical analysis of the ...
CHENG Zishuo
doaj
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
AerospaceThe objective of the kinematic model of rock chips is to examine the impact of the driving parameters of drilling tools on the effective chip removal speed, with a view to analyze the chip removal performance of rotary percussion ultrasonic drilling. The
Yinchao Wang +6 more
doaj +1 more source
Tool wear monitoring and hole surface quality during CFRP drilling [PDF]
, 2014 The present investigation focuses on the evaluation of tool wear and surface integrity in the context of CFRP cutting. Series of drilling experiments were performed on CFRP plates using cemented carbide solid drills with the aim to investigate ...
RAMIREZ, Christophe +3 more
core +1 more source