Numerical modelling of strain localization by anisotropy generation during viscous deformation

2021 ◽  
Author(s):  
William R. Halter ◽  
Emilie Macherel ◽  
Thibault Duretz ◽  
Stefan M. Schmalholz
Keyword(s):  
Strain Localization ◽  
Finite Strain ◽  
Shear Zones ◽  
Reduction Reaction ◽  
Thermal Softening ◽  
Two Dimensional ◽  
Viscous Deformation ◽  
Viscous Material ◽  
First Results ◽  
The Impact

<p>Localization and softening mechanisms in a deforming lithosphere are important for subduction initiation or the generation of tectonic nappes during orogeny. Many localization mechanisms have been proposed as being important during the viscous, creeping, deformation of the lithosphere, such as thermal softening, grain size reduction, reaction-induced softening or anisotropy development. However, which localization mechanism is the controlling one and under which deformation conditions is still contentious. In this contribution, we focus on strain localization in viscous material due to the generation of anisotropy, for example due to the development of a foliation. We numerically model the generation and evolution of anisotropy during two-dimensional viscous deformation in order to quantify the impact of anisotropy development on strain localization and on the effective softening. We use a pseudo-transient finite difference (PTFD) method for the numerical solution. We calculate the finite strain ellipse during viscous deformation. The aspect ratio of the finite strain ellipse serves as proxy for the magnitude of anisotropy, which determines the ratio of normal to tangential viscosity. To track the orientation of the anisotropy during deformation, we apply the so-called director method. We will present first results of our numerical simulations and discuss their application to natural shear zones.</p>

scholarly journals Dramatic effect of elasticity on thermal softening and strain localization during lithospheric shortening

2015 ◽  
Vol 204 (2) ◽  
pp. 780-784 ◽  
Author(s):  
Yoann Jaquet ◽  
Thibault Duretz ◽  
Stefan M. Schmalholz
Keyword(s):  
Energy Release ◽  
Strain Localization ◽  
Strain Energy ◽  
Plate Tectonics ◽  
Elastic Strain Energy ◽  
Shear Zones ◽  
Thermal Softening ◽  
Lower Crustal ◽  
The Impact ◽  
Related Increase

Abstract We present two-dimensional numerical simulations for shortening a viscoelastoplastic lithosphere to quantify the impact of elasticity on strain localization due to thermal softening. The model conserves energy and mechanical work is converted into heat or stored as elastic strain energy. For a shear modulus G = 1010 Pa, a prominent lithospheric shear zone forms and elastic energy release increases the localization intensity (strain rate amplification). For G = 5 × 1010 Pa shear zones still form but deformation is less localized. For G = 1012 Pa, the lithosphere behaves effectively viscoplastic and no shear zones form during homogeneous thickening. Maximal shearing-related increase of surface heat flux is 15–25 mW m−2 and of temperature at lower crustal depth is ∼150 °C, whereby these peak values are transient (0.1–1 My). Elasticity and related energy release can significantly contribute to strain localization and plate-like behaviour of the lithosphere required for plate tectonics.

Recent Advances and Need of Green Synthesis in Two-Dimensional Materials for Energy Conversion and Storage Applications

2021 ◽  
Vol 16 ◽  
Author(s):  
Joice Sophia Ponraj ◽  
Muniraj Vignesh Narayanan ◽  
Ranjith Kumar Dharman ◽  
Valanarasu Santiyagu ◽  
Ramalingam Gopal ◽  
...  
Keyword(s):  
Energy Storage ◽  
Green Synthesis ◽  
2D Materials ◽  
Synthesis Method ◽  
Energy Storage And Conversion ◽  
Two Dimensional ◽  
Severe Problem ◽  
Energy Conversion And Storage ◽  
Energy Application ◽  
The Impact

: Increasing energy crisis across the globe requires immediate solutions. Two-dimensional (2D) materials are in great significance because of its application in energy storage and conversion devices but the production process significantly impacts the environment thereby posing a severe problem in the field of pollution control. Green synthesis method provides an eminent way of reduction in pollutants. This article reviews the importance of green synthesis in the energy application sector. The focus of 2D materials like graphene, MoS2, VS2 in energy storage and conversion devices are emphasized based on supporting recent reports. The emerging Li-ion batteries are widely reviewed along with their promising alternatives like Zn, Na, Mg batteries and are featured in detail. The impact of green methods in the energy application field are outlined. Moreover, future outlook in the energy sector is envisioned by proposing an increase in 2D elemental materials research.

Boosting electrochemical nitrogen reduction reaction performance of two-dimensional Mo porphyrin monolayers via turning the coordination environment

2021 ◽  
Vol 23 (7) ◽  
pp. 4178-4186
Author(s):  
Shiqiang Liu ◽  
Zhiwen Cheng ◽  
Yawei Liu ◽  
Xiaoping Gao ◽  
Yujia Tan ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Reduction Reaction ◽  
Metal Catalysts ◽  
Two Dimensional ◽  
Coordination Environment ◽  
Nitrogen Reduction ◽  
Reaction Performance ◽  
Conversion Efficiencies

Designing atomically dispersed metal catalysts for the nitrogen reduction reaction (NRR) is an effective approach to achieve better energy conversion efficiencies.

scholarly journals Mixed NNLO QCD×electroweak corrections of $$ \mathcal{O} $$(Nfαsα) to single-W/Z production at the LHC

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Stefan Dittmaier ◽  
Timo Schmidt ◽  
Jan Schwarz
Keyword(s):  
Z Bosons ◽  
Leading Order ◽  
Current Standard ◽  
Gauge Invariant ◽  
Mass Distributions ◽  
Self Energy ◽  
Electroweak Gauge Boson ◽  
First Results ◽  
Invariant Part ◽  
The Impact

Abstract First results on the radiative corrections of order $$ \mathcal{O} $$ O (Nfαsα) are presented for the off-shell production of W or Z bosons at the LHC, where Nf is the number of fermion flavours. These corrections comprise all diagrams at $$ \mathcal{O} $$ O (αsα) with closed fermion loops, form a gauge-invariant part of the next-to-next-to-leading-order corrections of mixed QCD×electroweak type, and are the ones that concern the issue of mass renormalization of the W and Z resonances. The occurring irreducible two-loop diagrams, which involve only self-energy insertions, are calculated with current standard techniques, and explicit analytical results on the electroweak gauge-boson self-energies at $$ \mathcal{O} $$ O (αsα) are given. Moreover, the generalization of the complex-mass scheme for a gauge-invariant treatment of the W/Z resonances is described for the order $$ \mathcal{O} $$ O (αsα). While the corrections, which are implemented in the Monte Carlo program Rady, are negligible for observables that are dominated by resonant W/Z bosons, they affect invariant-mass distributions at the level of up to 2% for invariant masses of ≳ 500 GeV and are, thus, phenomenologically relevant. The impact on transverse-momentum distributions is similar, taking into account that leading-order predictions to those distributions underestimate the spectrum.

scholarly journals Rheological Contrast between Quartz and Coesite Generates Strain Localization in Deeply Subducted Continental Crust

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Kouhei Asano ◽  
Katsuyoshi Michibayashi ◽  
Tomohiro Takebayashi
Keyword(s):  
Rheological Behavior ◽  
Strain Localization ◽  
Shear Zones ◽  
Ultrahigh Pressure ◽  
Ultramafic Rocks ◽  
Crustal Material ◽  
Orientation Data ◽  
Crystallographic Preferred Orientation ◽  
Dabie Shan ◽  
Felsic Rocks

Deformation microstructures of peak metamorphic conditions in ultrahigh-pressure (UHP) metamorphic rocks constrain the rheological behavior of deeply subducted crustal material within a subduction channel. However, studies of such rocks are limited by the overprinting effects of retrograde metamorphism during exhumation. Here, we present the deformation microstructures and crystallographic-preferred orientation data of minerals in UHP rocks from the Dabie–Shan to study the rheological behavior of deeply subducted continental material under UHP conditions. The studied samples preserve deformation microstructures that formed under UHP conditions and can be distinguished into two types: high-strain mafic–ultramafic samples (eclogite and garnet-clinopyroxenite) and low-strain felsic samples (jadeite quartzite). This distinction suggests that felsic rocks are less strained than mafic–ultramafic rocks under UHP conditions. We argue that the phase transition from quartz to coesite in the felsic rocks may explain the microstructural differences between the studied mafic–ultramafic and felsic rock samples. The presence of coesite, which has a higher strength than quartz, may result in an increase in the bulk strength of felsic rocks, leading to strain localization in nearby mafic–ultramafic rocks. The formation of shear zones associated with strain localization under HP/UHP conditions can induce the detachment of subducted crustal material from subducting lithosphere, which is a prerequisite for the exhumation of UHP rocks. These findings suggest that coesite has an important influence on the rheological behavior of crustal material that is subducted to coesite-stable depths.

Elongated Heterometal Double-Sites Promote Nitrogen Reduction on Two-Dimensional MM’B7 Monolayers

2021 ◽  
Author(s):  
Changyan Zhu ◽  
Chaoxia Wen ◽  
Cong Wang ◽  
Min Zhang ◽  
Yun Geng ◽  
...  
Keyword(s):  
Reduction Reaction ◽  
Two Dimensional ◽  
Long Distance ◽  
Nitrogen Reduction ◽  
Crucial Step

The efficient activation of the adsorbed N2 is the initial and crucial step in the electrochemical nitrogen reduction reaction (NRR) but remains a long-standing challenge. Attaching long-distance heterometal M and...

Cooling Efficiencies of a NiTi-Based Cooling Process

2013 ◽  
Author(s):  
Marvin Schmidt ◽  
Andreas Schütze ◽  
Stefan Seelecke
Keyword(s):  
Solid State ◽  
Thermodynamic Analysis ◽  
Cooling System ◽  
Analysis Method ◽  
Efficiency Ratio ◽  
Cooling Process ◽  
First Results ◽  
Work Input ◽  
Underlying Mechanisms ◽  
The Impact

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.

First-principles screening of single transition metal atoms anchored on two-dimensional C9N4 for the nitrogen reduction reaction

2021 ◽  
Vol 23 (14) ◽  
pp. 8784-8791
Author(s):  
Qingling Meng ◽  
Ling Zhang ◽  
Jinge Wu ◽  
Shuwei Zhai ◽  
Xiamin Hao ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Transition Metal ◽  
First Principles ◽  
Reduction Reaction ◽  
Single Atom ◽  
Two Dimensional ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Catalytically Active ◽  
Single Transition

Theoretical screening of transition metal atoms anchored on monolayer C9N4 as highly stable, catalytically active and selective single-atom catalysts for nitrogen fixation.

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