Results 1 to 10 of about 2,998 (248)

Morphology of the Human Pineal Gland Studied by Freeze-Fracturing in Scanning Electron Microscopy [PDF]

Life
The human pineal gland is the largest producer of the hormone melatonin. Pineal acervuli (brain sand), calcified concretions in the pineal gland, have long been studied because of their association with ageing, melatonin production, and neurological ...
Simona Polakovičová, Ján Líška, Ivan Varga, Paulína Gálfiová   +3 more
doaj   +2 more sources

Improving permeability of coal seams by freeze-fracturing method: The characterization of pore structure changes under low-field NMR

Energy Reports, 2020
The method of improving permeability of coal seams by freeze-fracturing is presented to accelerate the diffusion of coalbed gas into exploited wells.
Fakai Wang, Yongjiang Luo, Yunpei Liang   +2 more
exaly   +3 more sources

Enhancement mechanisms of coal permeability under water saturated conditions using liquid nitrogen freeze thaw cycles [PDF]

Scientific Reports
In order to investigate the effect of cyclic freeze-thaw of liquid nitrogen on the fracturing and permeability enhancement of water-rich coal seam, the conventional triaxial loading experiments and nuclear magnetic resonance (NMR) experiments after ...
Xiaohan Qi, Yong Zhang, Shuangrong Hou, Tian Ning, Qiang Lv   +4 more
doaj   +2 more sources

Evaluating shear strength and acoustic emission in rock-like materials with non-persistent joint geometries under freeze-thaw conditions [PDF]

Scientific Reports
This study examines the effects of freeze-thaw cycles and the geometric configuration of non-persistent joints on the shear behavior of rock masses. Various artificial rock samples with non-persistent joints underwent direct shear testing to investigate ...
Sadegh Kefayati, Mosleh Eftekhari, Kamran Goshtasbi, Morteza Ahmadi   +3 more
doaj   +2 more sources

Freeze fracturing of elastic porous media: a mathematical model [PDF]

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2015
M G Worster
exaly   +2 more sources

Study on evolution law of mechanical properties of coal samples subjected to freezing and freeze-thaw cycles of liquid nitrogen

Meitan kexue jishu, 2023
The permeability of coal reservoir is generally low in China, how to effectively improve the permeability of coal reservoir is a key and difficult point of coalbed methane exploitation, Liquid nitrogen fracturing technology as a kind waterless fracturing
Yapei CHU, Dongming ZHANG, Han YANG, Heng LIU, Xuyang WU, Tong SHEN, Panpan ZHAI   +6 more
doaj   +1 more source

Characteristics Evolution of Multiscale Structures in Deep Coal under Liquid Nitrogen Freeze-Thaw Cycles

Geofluids, 2021
Liquid nitrogen freeze-thaw fracturing has attracted more and more attention in improving the coal reservoir permeability. In order to reveal the impact of liquid nitrogen freeze-thaw on the multiscale structure of deep coal, the multiscale structure ...
Yingfeng Sun, Yixin Zhao, Yulin Li, Nima Noraei Danesh, Zetian Zhang   +4 more
doaj   +1 more source

Pore structure and fractal analysis of coal subjected to multiple treatments based on nuclear magnetic resonance

Energy Science & Engineering, 2022
Microwave heating (MW) and freeze fracturing (FF) have been widely used for enhancing the permeability of coal reservoirs. In this paper, the effects of combined MW–FF treatments on coals are experimentally investigated through nuclear magnetic resonance.
Zairong Yang, Yu Zhao, Chaolin Wang, Jing Bi   +3 more
doaj   +1 more source

Fractal-Based Retrieval and Potential Driving Factors of Lake Ice Fractures of Chagan Lake, Northeast China Using Landsat Remote Sensing Images

Remote Sensing, 2021
A thorough understanding of the freshwater ice process received considerable critical attention due to increasing winter recreations and ice engineering.
Xiaohua Hao, Qian Yang, Xiaoguang Shi, Xuemei Liu, Wenfeng Huang, Liwen Chen, Yue Ma   +6 more
doaj   +1 more source

Molecular Cytology of ‘Little Animals’: Personal Recollections of Escherichia coli (and Bacillus subtilis)

Life, 2023
This article relates personal recollections and starts with the origin of electron microscopy in the sixties of the previous century at the University of Amsterdam.
Nanne Nanninga
doaj   +1 more source