Diffusion characteristics of biological extinction material

2017 ◽  
Vol 46 (6) ◽  
pp. 621001
Author(s):  
李 乐 Li Le ◽  
胡以华 Hu Yihua ◽  
王 枭 Wang Xiao ◽  
顾有林 Gu Youlin ◽  
赵义正 Zhao Yizheng ◽  
...  
Keyword(s):  
Diffusion Characteristics ◽  
Biological Extinction

Diffusion characteristics of plasma nitrided hard chromium on AISI 1010 steel

2015 ◽  
Vol 57 (5) ◽  
pp. 443-446 ◽  
Author(s):  
Murat Danışman ◽  
Mustafa Kocabaş ◽  
Nurhan Cansever
Keyword(s):  
Hard Chromium ◽  
Diffusion Characteristics

Flood Basalts and Mass Extinctions

2019 ◽  
Vol 47 (1) ◽  
pp. 275-303 ◽  
Author(s):  
Matthew E. Clapham ◽  
Paul R. Renne
Keyword(s):  
Environmental Changes ◽  
Flood Basalt ◽  
Respiratory Physiology ◽  
Mass Extinctions ◽  
Flood Basalts ◽  
Volatile Release ◽  
Ocean Carbon ◽  
Biological Extinction ◽  
Extinction Events ◽  
Environmental Disruption

Flood basalts were Earth's largest volcanic episodes that, along with related intrusions, were often emplaced rapidly and coincided with environmental disruption: oceanic anoxic events, hyperthermals, and mass extinction events. Volatile emissions, both from magmatic degassing and vaporized from surrounding rock, triggered short-term cooling and longer-term warming, ocean acidification, and deoxygenation. The magnitude of biological extinction varied considerably, from small events affecting only select groups to the largest extinction of the Phanerozoic, with less-active organisms and those with less-developed respiratory physiology faring especially poorly. The disparate environmental and biological outcomes of different flood basalt events may at first order be explained by variations in the rate of volatile release modulated by longer trends in ocean carbon cycle buffering and the composition of marine ecosystems. Assessing volatile release, environmental change, and biological extinction at finer temporal resolution should be a top priority to refine ancient hyperthermals as analogs for anthropogenic climate change. ▪ Flood basalts, the largest volcanic events in Earth history, triggered dramatic environmental changes on land and in the oceans. ▪ Rapid volcanic carbon emissions led to ocean warming, acidification, and deoxygenation that often caused widespread animal extinctions. ▪ Animal physiology played a key role in survival during flood basalt extinctions, with reef builders such as corals being especially vulnerable. ▪ The rate and duration of volcanic carbon emission controlled the type of environmental disruption and the severity of biological extinction.

Numerical Simulation of Radon Atmospheric Dynamic Diffusion from a Flat Ground Uranium Tailings Impoundment

2013 ◽  
Vol 807-809 ◽  
pp. 628-631
Author(s):  
Xiao Yong Peng ◽  
Xin Zhang ◽  
Shuai Huang ◽  
Xu Sheng Chai ◽  
Lan Xia Guo
Keyword(s):  
Numerical Simulation ◽  
Mass Fraction ◽  
Space Distribution ◽  
Time And Space ◽  
Tailings Impoundment ◽  
Diffusion Characteristics ◽  
Atmospheric Dynamic ◽  
Uranium Tailings ◽  
Dynamic Diffusion ◽  
Flat Ground

with a flat ground uranium tailings impoundment as the object of the paper, CFD technology was used to study the atmospheric dynamic diffusion characteristics and the evolution of time and space distribution of radon in the uranium tailings impoundment. Results show that, within 1500m range of the leeward of uranium tailings impoundment the falling gradient of radon mass fraction improves with distance increases at the same moment, however the falling gradient flattens with the increase of time gradually; During the first 30 minutes, the radon mass fraction of tailings impoundment in the leeward direction has a larger growth gradient, then flattens out slowly, and stabilizes after 75 minutes.

Diffusion characteristics of boron and phosphorus in polycrystalline silicon

1983 ◽  
Vol 100 (3) ◽  
pp. 235-248 ◽  
Author(s):  
A.D. Buonaquisti ◽  
W. Carter ◽  
P.H. Holloway
Keyword(s):  
Polycrystalline Silicon ◽  
Diffusion Characteristics

Effects of Wind on the Heat Flow of FPSO Topsides Subject to Fire: An Experimental and Numerical Study

2010 ◽  
Author(s):  
Joon Young Yoon ◽  
Seong Hwan Kim ◽  
Gwon Cheol Yu ◽  
Jung Kwan Seo ◽  
Bong Ju Kim ◽  
...  
Keyword(s):  
Thermal Diffusion ◽  
Numerical Study ◽  
Wind Tunnel Test ◽  
Experimental Results ◽  
Test Facility ◽  
Test Model ◽  
Cfd Simulations ◽  
Fire Engineering ◽  
Diffusion Characteristics ◽  
Fire Loads

The aim of this paper is to examine the effect of wind on the thermal diffusion characteristics of floating production storage and offloading (FSPO) topside models subject to fire. It is motivated by the need to identify the fire loads on FPSO topsides, taking into account the effects of wind speed and direction. The results of an experimental and numerical study undertaken for these purposes are reported here. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. An experiment was performed on a 1/14-scale FPSO topside model using a wind tunnel test facility. The locations of the heat source of the fire were varied, as were the speed and direction of the wind, and the temperature distribution was measured. Computational fluid dynamics (CFD) simulations using the ANSYS CFX program were performed on the test model, with the results obtained compared with the experimental results. It is concluded that wind has a significant effect on the thermal diffusion characteristics of the test model and that the CFD simulations are in good agreement with the experimental results. The insights developed in this study will be very useful for the fire engineering of FPSO topsides.

Organic Heterojunctions for Photovoltaic Applications: C60 Growth on Pentacene

2010 ◽  
Vol 1263 ◽  
Author(s):  
Rebecca Ann Cantrell ◽  
Paulette Clancy
Keyword(s):  
Atomic Scale ◽  
Short Axis ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
The North ◽  
Diffusion Characteristics ◽  
Static Energy ◽  
Semi Empirical ◽  
Organic Heterojunctions ◽  
And Diffusion

AbstractUsing atomic-scale Molecular Dynamics (MD) and energy minimization techniques in conjunction with semi-empirical MM3 potential energy functions, we consider the adsorption of a C60 molecule on a series of hypothetical pentacene structures that vary only in the tilt of the angle that the short axis of the pentacene molecules makes with the underlying surface (the long axis lying essentially flat, as on a metal substrate). Important relationships were discovered between the angle adopted by the short axis of pentacene on the surface, φ1, and the adsorption and diffusion characteristics of C60. Static energy calculations show that there is a transition of the deepest energy minima from between the pentacene rows at low values of φ1 to within the rows at high values of φ1, where φ1 is the angle the pentacene short axis makes with the surface. MD confirms this trend by the predominant residence locations at the extreme φ1 values. Furthermore, MD results suggest that the C60 traverses the pentacene surface in the east-west direction for lower φ1 values (φ1 ≤ 40°) and in the north-south direction for higher φ1 values (φ1 ≥ 70°). Taking both static and dynamic results together, the most favorable tilt angles for mono-directional nanowire growth should occur between 70° and 80° off-normal.

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