Results 41 to 50 of about 717 (138)

Influence of particle characteristics on dynamic characteristics of tail beam under coal rock caving impact

Frontiers in Energy Research, 2022
In order to improve the accuracy of simulation parameters used in the discrete element simulation test of a fully mechanized top-coal caving process and further explore the intelligent fully mechanized coal caving technology, this research work studies ...
Lijuan Zhao, Lijuan Zhao, Liguo Han, Haining Zhang, Man Ge, Shijie Yang, Xin Jin   +6 more
doaj   +1 more source

Late Holocene environmental history of Dojran, Macedonia: Investigating the interplay of imperial dynamics and climatic change

Journal of Quaternary Science, EarlyView.
ABSTRACT This study presents a high‐resolution, multi‐proxy reconstruction of environmental and land‐use change from Lake Dojran over historical times (last 2500 years), combining pollen, biomarkers, radiocarbon dating, Ottoman taxation records and other historical data.
Alessia Masi, Lucrezia Masci, Georgios C. Liakopoulos, Monica Bini, Alexander Francke, Ilaria Isola, Carlo Ricotta, Laura Sadori, Alexander Sarantis, Sławomir Sprawski, Jakub Sypiański, Irene Tunno, Cristiano Vignola, Bernd Wagner, Giovanni Zanchetta, Adam Izdebski   +15 more
wiley   +1 more source

Mechanism by Which Backfill Body Reduces Amount of Energy Released in Deep Coal Mining

Shock and Vibration, 2019
Deep coal mining is unavoidable, and the complex mining environments and the increasing dangers associated with ultrahigh energy accumulation and release from mining disturbances renders it extremely difficult to maintain a safe and stable stope.
Wenyue Qi, Jixiong Zhang, Nan Zhou, Zhongya Wu, Jun Zhang   +4 more
doaj   +1 more source

The Early Upper Palaeolithic open‐air site of Friedrichsdorf‐Seulberg, Germany, in the context of the northern central European Aurignacian

Boreas, EarlyView.
Our knowledge of the Early Upper Palaeolithic occupation in northern central Europe is very limited, and recent research at the open‐air site of Friedrichsdorf‐Seulberg in Hesse, Germany, provides important new information on the Aurignacian. The site is rather small (26.5 m2) and spatial analysis identified a central hearth with two associated ...
Tilman Böckenförde, Gabriele Russo, Neda Rahimzadeh, Felix Bittmann, Nikolitsa Nikolakopoulou, Thomas Terberger   +5 more
wiley   +1 more source

Research progress on intelligent coal caving theory and technology

Gong-kuang zidonghua
The longwall top-coal caving technology is an effective method for extracting thick and ultra-thick coal seams, and it has become a hallmark technology in China's coal mining industry.
WANG Jiachen, YANG Shengli, LI Lianghui, ZHANG Jinwang, WEI Weijie   +4 more
doaj   +1 more source

Regional Trade Agreements and International R&D Spillovers: Implications for Developing Countries

The Developing Economies, EarlyView.
ABSTRACT We provide new evidence on heterogeneous international research and development (R&D) spillovers from partners of regional trade agreements (RTAs) and non‐partners using a sample of 45 economies in the period 1995–2017. We construct separate R&D stocks for RTA partners and non‐partners and find that spillovers from RTA partners are stronger ...
Yukiko Sawada, Rinki Ito, Naoto Jinji
wiley   +1 more source

Managing agency business groups, elite directors, and the rubber boom, 1897–1913

The Economic History Review, EarlyView.
Abstract We identify a new organizational form, the Managing Agency Business Group (MABG), demonstrating how agency houses used interlocking directorships to build groups on the basis of commercial and plantation expertise to access finance on London stock markets and local capital markets in the pre‐1914 rubber boom.
David Higgins, Steven Toms
wiley   +1 more source

The Evolution of Autonomous Systems for Planetary Cave Exploration: A Review

Journal of Field Robotics, Volume 43, Issue 6, Page 4094-4115, September 2026.
ABSTRACT The exploration of Subsurface Access Points (SAPs), such as lava tubes on the Moon and Mars, has gained significant interest due to their potential as stable environments shielded from surface radiation and temperature extremes. These sites are considered high‐value targets for detecting water and signs of ancient life, and assessing their ...
Sarah Swinton, Daniel Mitchell, Jamie Blanche, Euan McGookin, David Flynn   +4 more
wiley   +1 more source

Study of evaluation of economic rock-mixed ratio of longwall top-coal caving working face based on entropy weight-extension theory

Meitan kexue jishu
The rock-mixed ratio of top-coal caving mining significantly affects the coal quality and economic benefits. This ratio at longwall top-coal caving (LTCC) faces is jointly determined by multiple factors, including geological conditions, extracting and ...
Shen WANG, Ruixiang LI, Dongyin LI, Peng LYU, Ru FENG, Hongbin LI, Wen WANG   +6 more
doaj   +1 more source

Study on the Characteristics of Top-Coal Caving and Optimization of Recovery Ratio in Steeply Inclined Residual High Sectional Coal Pillar

Geofluids, 2020
This paper is aimed at solving the technical problems such as low recovery ratio and frequent disasters in steeply inclined and extrathick coal seams at residual high sectional coal pillar.
Wenhua Yang, Xingping Lai, Pengfei Shan, Feng Cui, Yiran Yang   +4 more
doaj   +1 more source