Large-Scale Layer-by-Layer Synthesis of Borophene on Ru(0001)

2021 ◽  
Author(s):  
Peter Sutter ◽  
Eli Sutter
Keyword(s):  
Large Scale ◽  
Layer By Layer ◽  
Scale Layer

Large-scale layer-by-layer inkjet printing of flexible iridium-oxide based pH sensors

2018 ◽  
Vol 819 ◽  
pp. 384-390 ◽  
Author(s):  
Milica Jović ◽  
Jonnathan C. Hidalgo-Acosta ◽  
Andreas Lesch ◽  
Victor Costa Bassetto ◽  
Evgeny Smirnov ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Large Scale ◽  
Iridium Oxide ◽  
Layer By Layer ◽  
Ph Sensors ◽  
Scale Layer

Evolution of Metastable Structures in Bimetallic Catalysts from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Christopher R. O’Connor ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Complete Characterization ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
Underlying Mechanisms

Restructuring of interface plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of the long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. Encapsulation of Pd by Ag always precedes layer-by-layer dissolution of Pd, resulting in significant Ag migration out of the surface and extensive vacancy pits. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. The underlying mechanisms are uncovered by performing fast and large-scale machine-learning molecular dynamics, followed by our newly developed method for complete characterization of atomic surface restructuring events. Our approach is broadly applicable to other multimetallic systems of interest and enables the previously impractical mechanistic investigation of restructuring dynamics.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

scholarly journals Large-Scale Molecular Dynamics Simulations Reveal New Insights Into the Phase Transition Mechanisms in MIL-53(Al)

2021 ◽  
Vol 9 ◽  
Author(s):  
Sander Vandenhaute ◽  
Sven M. J. Rogge ◽  
Veronique Van Speybroeck
Keyword(s):  
Large Scale ◽  
Pressure Control ◽  
Layer By Layer ◽  
Major Step ◽  
Transition Mechanism ◽  
External Pressures ◽  
Pressure Regime ◽  
Dynamics Simulations ◽  
Experimental Crystal ◽  
External Stimuli

Soft porous crystals have the ability to undergo large structural transformations upon exposure to external stimuli while maintaining their long-range structural order, and the size of the crystal plays an important role in this flexible behavior. Computational modeling has the potential to unravel mechanistic details of these phase transitions, provided that the models are representative for experimental crystal sizes and allow for spatially disordered phenomena to occur. Here, we take a major step forward and enable simulations of metal-organic frameworks containing more than a million atoms. This is achieved by exploiting the massive parallelism of state-of-the-art GPUs using the OpenMM software package, for which we developed a new pressure control algorithm that allows for fully anisotropic unit cell fluctuations. As a proof of concept, we study the transition mechanism in MIL-53(Al) under various external pressures. In the lower pressure regime, a layer-by-layer mechanism is observed, while at higher pressures, the transition is initiated at discrete nucleation points and temporarily induces various domains in both the open and closed pore phases. The presented workflow opens the possibility to deduce transition mechanism diagrams for soft porous crystals in terms of the crystal size and the strength of the external stimulus.

Proactive Optimization of Intelligent-Well Production Using Stochastic Gradient-Based Algorithms

2016 ◽  
Vol 19 (02) ◽  
pp. 239-252 ◽  
Author(s):  
Morteza Haghighat Sefat ◽  
Khafiz M. Muradov ◽  
Ahmed H. Elsheikh ◽  
David R. Davies
Keyword(s):  
Large Scale ◽  
Optimization Problem ◽  
Stochastic Gradient ◽  
Real Field ◽  
Directional Derivatives ◽  
Optimization Approach ◽  
Layer By Layer ◽  
Monitoring And Control ◽  
Ensemble Size ◽  
Local Optima

Summary The popularity of intelligent wells (I-wells), which provide layer-by-layer monitoring and control capability of production and injection, is growing. However, the number of available techniques for optimal control of I-wells is limited (Sarma et al. 2006; Alghareeb et al. 2009; Almeida et al. 2010; Grebenkin and Davies 2012). Currently, most of the I-wells that are equipped with interval control valves (ICVs) are operated to enhance the current production and to resolve problems associated with breakthrough of the unfavorable phase. This reactive strategy is unlikely to deliver the long-term optimum production. On the other side, the proactive-control strategy of I-wells, with its ambition to provide the optimum control for the entire well's production life, has the potential to maximize the cumulative oil production. This strategy, however, results in a high-dimensional, nonlinear, and constrained optimization problem. This study provides guidelines on selecting a suitable proactive optimization approach, by use of state-of-the-art stochastic gradient-approximation algorithms. A suitable optimization approach increases the practicality of proactive optimization for real field models under uncertain operational and subsurface conditions. We evaluate the simultaneous-perturbation stochastic approximation (SPSA) method (Spall 1992) and the ensemble-based optimization (EnOpt) method (Chen et al. 2009). In addition, we present a new derivation of the EnOpt by use of the concept of directional derivatives. The numerical results show that both SPSA and EnOpt methods can provide a fast solution to a large-scale and multiple I-well proactive optimization problem. A criterion for tuning the algorithms is proposed and the performance of both methods is compared for several test cases. The used methodology for estimating the gradient is shown to affect the application area of each algorithm. SPSA provides a rough estimate of the gradient and performs better in search environments, characterized by several local optima, especially with a large ensemble size. EnOpt was found to provide a smoother estimation of the gradient, resulting in a more-robust algorithm to the choice of the tuning parameters, and a better performance with a small ensemble size. Moreover, the final optimum operation obtained by EnOpt is smoother. Finally, the obtained criteria are used to perform proactive optimization of ICVs in a real field.

Millimeter-sized PbI2 flakes and Pb5S2I6 nanowires for flexible photodetectors

2018 ◽  
Vol 6 (27) ◽  
pp. 7188-7194 ◽  
Author(s):  
Lin Sun ◽  
Chunrui Wang ◽  
Liu Xu ◽  
Jiale Wang ◽  
Xiaoshuang Chen ◽  
...  
Keyword(s):  
Large Scale ◽  
Scale Layer

Large-scale layer-structured PbI2 flakes & Pb5S2I6 nanowires for flexible photodetection.

Multimodal Image Fusion Method Based on Guided Filter

2021 ◽  
Author(s):  
Hui Zhang ◽  
Xinning Han ◽  
Rui Zhang
Keyword(s):  
Image Fusion ◽  
Large Scale ◽  
Fusion Rule ◽  
Guided Filter ◽  
Base Layer ◽  
Small Scale ◽  
Level Measurement ◽  
Scale Layer ◽  
Image Fusion Method ◽  
Multimodal Image Fusion

In the process of multimodal image fusion, how to improve the visual effect after the image fused, while taking into account the protection of energy and the extraction of details, has attracted more and more attention in recent years. Based on the research of visual saliency and the final action-level measurement of the base layer, a multimodal image fusion method based on a guided filter is proposed in this paper. Firstly, multi-scale decomposition of a guided filter is used to decompose the two source images into a small-scale layer, large-scale layer and base layer. The fusion rule of the maximum absolute value is adopted in the small-scale layer, the weight fusion rule based on regular visual parameters is adopted in the large-scale layer and the fusion rule based on activity-level measurement is adopted in the base layer. Finally, the fused three scales are laminated into the final fused image. The experimental results show that the proposed method can improve the image edge processing and visual effect in multimodal image fusion.

Fabrication of large-scale, layer-deposited, low oxygen-content and uniform silicon nanowires

2007 ◽  
Vol 303 (2) ◽  
pp. 391-394 ◽  
Author(s):  
Mingwang Shao ◽  
Hui Hu ◽  
Huizhao Ban ◽  
Min Li ◽  
Huazhong Gao
Keyword(s):  
Oxygen Content ◽  
Silicon Nanowires ◽  
Large Scale ◽  
Low Oxygen ◽  
Scale Layer

scholarly journals Hierarchical Structural Analysis Method for Complex Equation-Oriented Models

Mathematics ◽  
2021 ◽  
Vol 9 (21) ◽  
pp. 2660
Author(s):  
Chao Wang ◽  
Li Wan ◽  
Tifan Xiong ◽  
Yuanlong Xie ◽  
Shuting Wang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Large Scale ◽  
Complexity Analysis ◽  
Equation System ◽  
Complex Model ◽  
Layer By Layer ◽  
Analysis Method ◽  
Differential Algebraic Equation ◽  
Complex Equation ◽  
Complex Models

Structural analysis is a method for verifying equation-oriented models in the design of industrial systems. Existing structural analysis methods need flattening of the hierarchical models into an equation system for analysis. However, the large-scale equations in complex models make structural analysis difficult. Aimed to address the issue, this study proposes a hierarchical structural analysis method by exploring the relationship between the singularities of the hierarchical equation-oriented model and its components. This method obtains the singularity of a hierarchical equation-oriented model by analyzing a dummy model constructed with the parts from the decomposing results of its components. Based on this, the structural singularity of a complex model can be obtained by layer-by-layer analysis according to their natural hierarchy. The hierarchical structural analysis method can reduce the equation scale in each analysis and achieve efficient structural analysis of very complex models. This method can be adaptively applied to nonlinear-algebraic and differential-algebraic equation models. The main algorithms, application cases and comparison with the existing methods are present in this paper. The complexity analysis results show the enhanced efficiency of the proposed method in the structural analysis of complex equation-oriented models. Compared with the existing methods, the time complexity of the proposed method is improved significantly

scholarly journals Research Progress for Dynamic Effects of Cities on Precipitation: A Review

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1355
Author(s):  
Caijun Yue ◽  
Zhihui Han ◽  
Wen Gu ◽  
Yuqi Tang ◽  
Xiangyu Ao
Keyword(s):  
Tropical Cyclones ◽  
Large Scale ◽  
Horizontal Distribution ◽  
Research Progress ◽  
Layer By Layer ◽  
Distribution Characteristics ◽  
Dynamic Effects ◽  
Momentum Exchange ◽  
Extreme Precipitation Events ◽  
The Impact

Citization significantly changes original surface properties. City areas can cause surface winds to decrease; furthermore, ground friction can be transferred layer by layer through the momentum exchange of air movement, which affects the air layers above. Precipitation modification by city environments has been an active research area. Under the conditions of high wind speed, the dynamic effects of cities on precipitation are relatively obvious. Generally, the dynamic effects fall into two main categories: (1) for weather systems under weak forcing synoptic backgrounds, such as local convective systems, shorter-lived extreme precipitation events and fronts and city barrier effects can delay the movement of weather systems, directly change the horizontal distribution characteristics and occurrence time for precipitation, change the flow field and structure, cause the bifurcation of weather systems, and change the horizontal distribution characteristics of precipitation; (2) for weather systems under strong forcing synoptic backgrounds, such as extratropical systems (with large-scale moisture transport), monsoon systems, landfalling tropical cyclones, and supercell storms, the impact of the dynamic effects of cities cannot lead to the bifurcation of the weather system, nor can it change the horizontal distribution characteristics of the whole precipitation field, but it can have an impact on the local precipitation intensity and distribution. However, currently, people do not agree on the impact of cities on precipitation, especially regarding tropical cyclones. Hence, we provide a review and provide insights into the dynamic effects of cities on precipitation.

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