scholarly journals Ice: the paradigm of wild plasticity

2019 ◽  
Vol 377 (2146) ◽  
pp. 20180260 ◽  
Author(s):  
Jérôme Weiss
Keyword(s):  
Extreme Case ◽  
Model Material ◽  
Dislocation Dynamics ◽  
Research Activity ◽  
Crystalline Materials ◽  
Scale Free ◽  
Time Correlations ◽  
Long Time ◽  
Science Community ◽  
Material Science Community

Ice plasticity has been thoroughly studied, owing to its importance in glaciers and ice sheets dynamics. In particular, its anisotropy (easy basal slip) has been suspected for a long time, then fully characterized 40 years ago. More recently emerged the interest of ice as a model material to study some fundamental aspects of crystalline plasticity. An example is the nature of plastic fluctuations and collective dislocation dynamics. Twenty years ago, acoustic emission measurements performed during the deformation of ice single crystals revealed that plastic ‘flow’ proceeds through intermittent dislocation avalanches, power law distributed in size and energy. This means that most of ice plasticity takes place through few, very large avalanches, thus qualifying associated plastic fluctuations as ‘wild’. This launched an intense research activity on plastic intermittency in the Material Science community. The interest of ice in this debate is reviewed, from a comparison with other crystalline materials. In this context, ice appears as an extreme case of plastic intermittency, characterized by scale-free fluctuations, complex space and time correlations as well as avalanche triggering. In other words, ice can be considered as the paradigm of wild plasticity. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

scholarly journals Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas

2015 ◽  
Vol 373 (2041) ◽  
pp. 20140154 ◽  
Author(s):  
W. H. Matthaeus ◽  
Minping Wan ◽  
S. Servidio ◽  
A. Greco ◽  
K. T. Osman ◽  
...  
Keyword(s):  
Essential Feature ◽  
Dissipation Function ◽  
Astrophysical Plasmas ◽  
Structure Generation ◽  
Inverse Cascade ◽  
Time Correlations ◽  
Basic Physics ◽  
Long Time ◽  
Carry Over ◽  
Approach To Steady State

An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

scholarly journals Penerapan Metode MVC Framework Code Igniter untuk Sistem Informasi Administrasi Transaksi E-Commerce Perusahaan Aktualita

2021 ◽  
Vol 6 (1) ◽  
pp. 158
Author(s):  
Sunarto Usna ◽  
Andri Yanto ◽  
Soegijanto Soegijanto
Keyword(s):  
Data Collection ◽  
Data Processing ◽  
Administrative System ◽  
Research Activity ◽  
Good Data ◽  
Inaccurate Data ◽  
Long Time

Aktualita is one of the business activities engaged in the sale of stationery and printing located in South Jakarta. Activities related to promotions, data collection of goods, processing carried out do not yet have a standard database. Data processing takes a long time to produce information. The processing process contains errors in recording inaccurate data. Based on this information, the researchers tried to make a solution to these problems by creating a system in the form of a website using the CodeIgniter Framework. This research activity intends to find a solution with an administrative system for managing sales of goods transactions. The system built in this study uses a codeigniter framework. Making sales applications can be a solution to help make it easier for companies to actually manage goods data. Good data processing can make it easier to generate reports more quickly and accurately.

scholarly journals Transient Secondary Structures as General Target-Binding Motifs in Intrinsically Disordered Proteins

2018 ◽  
Vol 19 (11) ◽  
pp. 3614 ◽  
Author(s):  
Do-Hyoung Kim ◽  
Kyou-Hoon Han
Keyword(s):  
Intrinsically Disordered Proteins ◽  
Three Dimensional ◽  
Secondary Structures ◽  
Disordered Proteins ◽  
Ample Evidence ◽  
Binding Motifs ◽  
Intrinsically Disordered ◽  
Long Time ◽  
Science Community ◽  
Target Binding

Intrinsically disordered proteins (IDPs) are unorthodox proteins that do not form three-dimensional structures under non-denaturing conditions, but perform important biological functions. In addition, IDPs are associated with many critical diseases including cancers, neurodegenerative diseases, and viral diseases. Due to the generic name of “unstructured” proteins used for IDPs in the early days, the notion that IDPs would be completely unstructured down to the level of secondary structures has prevailed for a long time. During the last two decades, ample evidence has been accumulated showing that IDPs in their target-free state are pre-populated with transient secondary structures critical for target binding. Nevertheless, such a message did not seem to have reached with sufficient clarity to the IDP or protein science community largely because similar but different expressions were used to denote the fundamentally same phenomenon of presence of such transient secondary structures, which is not surprising for a quickly evolving field. Here, we summarize the critical roles that these transient secondary structures play for diverse functions of IDPs by describing how various expressions referring to transient secondary structures have been used in different contexts.

scholarly journals A Novel Approach of Parallel Retina-Like Computational Ghost Imaging

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7093
Author(s):  
Jie Cao ◽  
Dong Zhou ◽  
Fanghua Zhang ◽  
Huan Cui ◽  
Yingqiang Zhang ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Low Cost ◽  
Parallel Architecture ◽  
Structure Design ◽  
Ghost Imaging ◽  
Novel Approach ◽  
Time Correlations ◽  
Long Time ◽  
Sampling And Reconstruction ◽  
Similar Imaging

Computational ghost imaging (CGI), with the advantages of wide spectrum, low cost, and robustness to light scattering, has been widely used in many applications. The key issue is long time correlations for acceptable imaging quality. To overcome the issue, we propose parallel retina-like computational ghost imaging (PRGI) method to improve the performance of CGI. In the PRGI scheme, sampling and reconstruction are carried out by using the patterns which are divided into blocks from designed retina-like patterns. Then, the reconstructed image of each block is stitched into the entire image corresponding to the object. The simulations demonstrate that the proposed PRGI method can obtain a sharper image while greatly reducing the time cost than CGI based on compressive sensing (CSGI), parallel architecture (PGI), and retina-like structure (RGI), thereby improving the performance of CGI. The proposed method with reasonable structure design and variable selection may lead to improve performance for similar imaging methods and provide a novel technique for real-time imaging applications.

scholarly journals The new bud light steel system and the geometric shape evolution of light steel framework for COVID-19 patients appointed hospital (Huoshenshan hospital)

2020 ◽  
Vol 39 (6) ◽  
pp. 9015-9026
Author(s):  
Lilin Wang
Keyword(s):  
Simulation Analysis ◽  
Steel Structure ◽  
Model Material ◽  
Construction Process ◽  
Actual Measurement ◽  
Finite Element Software ◽  
Whole Process ◽  
Long Time ◽  
The Common ◽  
Actual Size

The light steel structure is always the common material of the movable plank house, and the new bud light steel system is the light steel system used for a long time after the earthquake. This paper discusses the mechanical system of the light steel structure of Huoshenshan hospital, which was built in ten days. In the process of building, the geometric form of roof stress has changed. In the actual structural design, the designer seldom takes the calculation of construction load into account, which is quite different from the actual construction process. So it is very important to simulate and monitor the whole process of structure installation. In this paper, the finite element software MIDAS / Gen is used for simulation analysis to ensure that the simulation analysis results are consistent with the construction process, the model material and the actual size are completely consistent, and the stress simulated by the software can meet the needs of the actual stress through the actual measurement.

scholarly journals Analysis of the Crack Initiation and Growth in Crystalline Materials Using Discrete Dislocations and the Modified Kitagawa–Takahashi Diagram

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 358
Author(s):  
Kuntimaddi Sadananda ◽  
Ilaksh Adlakha ◽  
Kiran N. Solanki ◽  
A.K. Vasudevan
Keyword(s):  
Crack Initiation ◽  
Crack Growth ◽  
Growth Kinetics ◽  
Dislocation Dynamics ◽  
Internal Stresses ◽  
Stress Concentrations ◽  
Crystalline Materials ◽  
Discrete Dislocation ◽  
Continuous Crack ◽  
American Society

Crack growth kinetics in crystalline materials is examined both from the point of continuum mechanics and discrete dislocation dynamics. Kinetics ranging from the Griffith crack to continuous elastic-plastic cracks are analyzed. Initiation and propagation of incipient cracks require very high stresses and appropriate stress gradients. These can be obtained either by pre-existing notches, as is done in a typical American Society of Testing and Materials (ASTM) fatigue and fracture tests, or by in situ generated stress concentrations via dislocation pile-ups. Crack growth kinetics are also examined using the modified Kitagawa–Takahashi diagram to show the role of internal stresses and their gradients needed to sustain continuous crack growth. Incipient crack initiation and growth are also examined using discrete dislocation modeling. The analysis is supported by the experimental data available in the literature.

Bulk Metallic Glasses

2008 ◽  
Vol 604-605 ◽  
pp. 229-238
Author(s):  
Marcello Baricco ◽  
Tanya A. Başer ◽  
Gianluca Fiore ◽  
Rafael Piccin ◽  
Marta Satta ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
Rapid Quenching ◽  
Second Phase ◽  
Research Activity ◽  
Long Time ◽  
Geometrical Constraints

Rapid quenching techniques have been successfully applied since long time for the preparation of metallic glasses in ribbon form. Only in the recent years, the research activity addressed towards the synthesis of bulk metallic glasses (BMG), in form of ingots with a few millimetres in thickness. These materials can be obtained by casting techniques only for selected alloy compositions, characterised by a particularly high glass-forming tendency. Bulk amorphous alloys are characterised by a low modulus of elasticity and high yielding stress. The usual idea is that amorphous alloys undergo work softening and that deformation is concentrated in shear bands, which might be subjected to geometrical constraints, resulting in a substantial increase in hardness and wear resistance. The mechanical properties can be further improved by crystallisation. In fact, shear bands movement can be contrasted by incorporating a second phase in the material, which may be produced directly by controlled crystallisation. Soft magnetic properties have been obtained in Fe-based systems and they are strongly related to small variations in the microstructure, ranging from a fully amorphous phase to nanocrystalline phases with different crystal size. The high thermal stability of bulk metallic glasses makes possible the compression and shaping processes in the temperature range between glass transition and crystallisation. Aim of this paper is to present recent results on glass formation and properties of bulk metallic glasses with various compositions. Examples will be reported on Zr, Fe, Mg and Pd-based materials, focussing on mechanical and magnetic properties.

scholarly journals SIMULATIONS OF FINANCIAL MARKETS IN A POTTS-LIKE MODEL

2005 ◽  
Vol 16 (08) ◽  
pp. 1311-1317 ◽  
Author(s):  
TETSUYA TAKAISHI
Keyword(s):  
Financial Markets ◽  
Financial Market ◽  
Potts Model ◽  
State Model ◽  
Exponential Distributions ◽  
Stylized Facts ◽  
Time Correlations ◽  
Long Time ◽  
Three State Model ◽  
Two State Model

A three-state model based on the Potts model is proposed to simulate financial markets. The three states are assigned to "buy", "sell" and "inactive" states. The model shows the main stylized facts observed in the financial market: fat-tailed distributions of returns and long time correlations in the absolute returns. At low inactivity rate, the model effectively reduces to the two-state model of Bornholdt and shows similar results to the Bornholdt model. As the inactivity increases, we observe the exponential distributions of returns.

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