scholarly journals Experiments in Surface Gravity–Capillary Wave Turbulence

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Eric Falcon ◽  
Nicolas Mordant
Keyword(s):  
Water Waves ◽  
Ocean Waves ◽  
System Size ◽  
Capillary Waves ◽  
Turbulence Theory ◽  
Wave Turbulence ◽  
Annual Review ◽  
Publication Date ◽  
Time Resolved ◽  
Advanced Analysis

The last decade has seen a significant increase in the number of studies devoted to wave turbulence. Many deal with water waves, as modeling of ocean waves has historically motivated the development of weak turbulence theory, which addresses the dynamics of a random ensemble of weakly nonlinear waves in interaction. Recent advances in experiments have shown that this theoretical picture is too idealized to capture experimental observations. While gravity dominates much of the oceanic spectrum, waves observed in the laboratory are in fact gravity–capillary waves, due to the restricted size of wave basins. This richer physics induces many interleaved physical effects far beyond the theoretical framework, notably in the vicinity of the gravity–capillary crossover. These include dissipation, finite–system size effects, and finite nonlinearity effects. Simultaneous space-and-time-resolved techniques, now available, open the way for a much more advanced analysis of these effects. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Double and Charge-Transfer Excitations in Time-Dependent Density Functional Theory

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Neepa T. Maitra
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Density Functional ◽  
System Size ◽  
Time Dependent ◽  
Annual Review ◽  
Publication Date ◽  
Functional Theory ◽  
Dependent Density ◽  
Made In

Time-dependent density functional theory has emerged as a method of choice for calculations of spectra and response properties in physics, chemistry, and biology, with its system-size scaling enabling computations on systems much larger than otherwise possible. While increasingly complex and interesting systems have been successfully tackled with relatively simple functional approximations, there has also been increasing awareness that these functionals tend to fail for certain classes of approximations. Here I review the fundamental challenges the approximate functionals have in describing double excitations and charge-transfer excitations, which are two of the most common impediments for the theory to be applied in a black-box way. At the same time, I describe the progress made in recent decades in developing functional approximations that give useful predictions for these excitations. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Vibrational Sum-Frequency Generation Hyperspectral Microscopy for Molecular Self-Assembled Systems

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Haoyuan Wang ◽  
Wei Xiong
Keyword(s):  
Hyperspectral Imaging ◽  
Sum Frequency Generation ◽  
Annual Review ◽  
Publication Date ◽  
Wide Field ◽  
Time Resolved ◽  
Sum Frequency ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Frequency Generation

In this review, we discuss the recent developments and applications of vibrational sum-frequency generation (VSFG) microscopy. This hyperspectral imaging technique can resolve systems without inversion symmetry, such as surfaces, interfaces and noncentrosymmetric self-assembled materials, in the spatial, temporal, and spectral domains. We discuss two common VSFG microscopy geometries: wide-field and confocal point-scanning. We then introduce the principle of VSFG and the relationships between hyperspectral imaging with traditional spectroscopy, microscopy, and time-resolved measurements. We further highlight crucial applications of VSFG microscopy in self-assembled monolayers, cellulose in plants, collagen fibers, and lattice self-assembled biomimetic materials. In these systems, VSFG microscopy reveals relationships between physical properties that would otherwise be hidden without being spectrally, spatially, and temporally resolved. Lastly, we discuss the recent development of ultrafast transient VSFG microscopy, which can spatially measure the ultrafast vibrational dynamics of self-assembled materials. The review ends with an outlook on the technical challenges of and scientific potential for VSFG microscopy. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

In Situ X-Ray Techniques for Electrochemical Interfaces

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Bruna F. Baggio ◽  
Yvonne Grunder
Keyword(s):  
Annual Review ◽  
Publication Date ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Recent Developments ◽  
In Operando ◽  
Electrochemical Interfaces ◽  
Ray Scattering

This article reviews progress in the study of materials using X-ray-based techniques from an electrochemistry perspective. We focus on in situ/in operando surface X-ray scattering, X-ray absorption spectroscopy, and the combination of both methods. The background of these techniques together with key concepts is introduced. Key examples of in situ and in operando investigation of liquid–solid and liquid–liquid interfaces are presented. X-ray scattering and spectroscopy have helped to develop an understanding of the underlying atomic and molecular processes associated with electrocatalysis, electrodeposition, and battery materials. We highlight recent developments, including resonant surface diffraction and time-resolved studies. Expected final online publication date for the Annual Review of Analytical Chemistry, Volume 14 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Mapping Enzyme Landscapes by Time-Resolved Crystallography with Synchrotron and X-Ray Free Electron Laser Light

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Mark A. Wilson
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Enzyme Catalysis ◽  
Energy Landscape ◽  
Annual Review ◽  
Publication Date ◽  
Ambient Conditions ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Crystallography

Directly observing enzyme catalysis in real time at the molecular level has been a long-standing goal of structural enzymology. Time-resolved serial crystallography methods at synchrotron and X-ray free electron laser (XFEL) sources have enabled researchers to follow enzyme catalysis and other nonequilibrium events at ambient conditions with unprecedented time resolution. X-ray crystallography provides detailed information about conformational heterogeneity and protein dynamics, which is enhanced when time-resolved approaches are used. This review outlines the ways in which information about the underlying energy landscape of a protein can be extracted from X-ray crystallographic data, with an emphasis on new developments in XFEL and synchrotron time-resolved crystallography. The emerging view of enzyme catalysis afforded by these techniques can be interpreted as enzymes moving on a time-dependent energy landscape. Some consequences of this view are discussed, including the proposal that irreversible enzymes or enzymes that use covalent catalytic mechanisms may commonly exhibit catalysis-activated motions. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Turbulence of capillary waves forced by steep gravity waves

2018 ◽  
Vol 850 ◽  
pp. 803-843 ◽  
Author(s):  
M. Berhanu ◽  
E. Falcon ◽  
L. Deike
Keyword(s):  
Nonlinear Wave ◽  
Power Law ◽  
Gravity Waves ◽  
Capillary Wave ◽  
Capillary Waves ◽  
Turbulence Theory ◽  
Wave Turbulence ◽  
Small Scale ◽  
Turbulent Regime ◽  
Strong Nonlinearity

We study experimentally the dynamics and statistics of capillary waves forced by random steep gravity waves mechanically generated in the laboratory. Capillary waves are produced here by gravity waves from nonlinear wave interactions. Using a spatio-temporal measurement of the free surface, we characterize statistically the random regimes of capillary waves in the spatial and temporal Fourier spaces. For a significant wave steepness (0.2–0.3), power-law spectra are observed both in space and time, defining a turbulent regime of capillary waves transferring energy from the large scale to the small scale. Analysis of temporal fluctuations of the spatial spectrum demonstrates that the capillary power-law spectra result from the temporal averaging over intermittent and strong nonlinear events transferring energy to the small scale in a fast time scale, when capillary wave trains are generated in a way similar to the parasitic capillary wave generation mechanism. The frequency and wavenumber power-law exponents of the wave spectra are found to be in agreement with those of the weakly nonlinear wave turbulence theory. However, the energy flux is not constant through the scales and the wave spectrum scaling with this flux is not in good agreement with wave turbulence theory. These results suggest that theoretical developments beyond the classic wave turbulence theory are necessary to describe the dynamics and statistics of capillary waves in a natural environment. In particular, in the presence of broad-scale viscous dissipation and strong nonlinearity, the role of non-local and non-resonant interactions should be reconsidered.

Scalable Control of Positive Systems

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Anders Rantzer ◽  
Maria Elena Valcher
Keyword(s):  
Formation Control ◽  
Evolutionary Dynamics ◽  
Autonomous Systems ◽  
Sufficient Conditions ◽  
System Size ◽  
Disturbance Attenuation ◽  
Annual Review ◽  
Control Problems ◽  
Publication Date ◽  
Positive Systems

In this article, we first present some foundational results about the stability and positive stabilization of continuous-time positive systems. Necessary and sufficient conditions for achieving stability are provided, together with some desired performance in terms of disturbance attenuation. These conditions are expressed in terms of linear programming and scale well with the system size. We then discuss the interconnection of positive subsystems by means of a static output feedback that preserves positivity, and propose conditions to achieve both stability and the asymptotic alignment of the closed-loop output to a desired vector. Finally, we describe some results for a class of parameterized positive systems. The second part of the article presents some interesting applications of the results presented in the first part. Specifically, control problems for heating networks, formation control, power control in wireless communication, and the evolutionary dynamics of cancer and HIV are formalized and solved as optimal control problems for positive systems. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 4 is May 3, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Endogenous Retroviruses Drive Resistance and Promotion of Exogenous Retroviral Homologs

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Elliott S. Chiu ◽  
Sue VandeWoude
Keyword(s):  
Immune Modulation ◽  
Viral Infections ◽  
Viral Evolution ◽  
Endogenous Retroviruses ◽  
Annual Review ◽  
Publication Date ◽  
Biological Functions ◽  
Self Tolerance ◽  
Vertebrate Hosts ◽  
Insight Into

Endogenous retroviruses (ERVs) serve as markers of ancient viral infections and provide invaluable insight into host and viral evolution. ERVs have been exapted to assist in performing basic biological functions, including placentation, immune modulation, and oncogenesis. A subset of ERVs share high nucleotide similarity to circulating horizontally transmitted exogenous retrovirus (XRV) progenitors. In these cases, ERV–XRV interactions have been documented and include ( a) recombination to result in ERV–XRV chimeras, ( b) ERV induction of immune self-tolerance to XRV antigens, ( c) ERV antigen interference with XRV receptor binding, and ( d) interactions resulting in both enhancement and restriction of XRV infections. Whereas the mechanisms governing recombination and immune self-tolerance have been partially determined, enhancement and restriction of XRV infection are virus specific and only partially understood. This review summarizes interactions between six unique ERV–XRV pairs, highlighting important ERV biological functions and potential evolutionary histories in vertebrate hosts. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 9 is February 16, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Advancing Socioeconomic Rights Through Interdisciplinary Factfinding: Opportunities and Challenges

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Sarah Knuckey ◽  
Joshua D. Fisher ◽  
Amanda M. Klasing ◽  
Tess Russo ◽  
Margaret L. Satterthwaite
Keyword(s):  
Human Rights ◽  
Mixed Methods ◽  
Social Science ◽  
Science Volume ◽  
Lessons Learned ◽  
Limited Resources ◽  
Annual Review ◽  
Publication Date ◽  
Socioeconomic Rights ◽  
Human Rights Movement

The human rights movement is increasingly using interdisciplinary, multidisciplinary, mixed-methods, and quantitative factfinding. There has been too little analysis of these shifts. This article examines some of the opportunities and challenges of these methods, focusing on the investigation of socioeconomic human rights. By potentially expanding the amount and types of evidence available, factfinding's accuracy and persuasiveness can be strengthened, bolstering rights claims. However, such methods can also present significant challenges and may pose risks in individual cases and to the human rights movement generally. Interdisciplinary methods can be costly in human, financial, and technical resources; are sometimes challenging to implement; may divert limited resources from other work; can reify inequalities; may produce “expertise” that disempowers rightsholders; and could raise investigation standards to an infeasible or counterproductive level. This article includes lessons learned and questions to guide researchers and human rights advocates considering mixed-methods human rights factfinding. Expected final online publication date for the Annual Review of Law and Social Science, Volume 17 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Conversation and Culture

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Simeon Floyd
Keyword(s):  
Conversation Analysis ◽  
Quantitative Methods ◽  
Sequential Analysis ◽  
Contemporary Literature ◽  
Annual Review ◽  
Publication Date ◽  
Face To Face ◽  
Qualitative And Quantitative Methods ◽  
Language Studies ◽  
Speech Communities

Conversation analysis is a method for the systematic study of interaction in terms of a sequential turn-taking system. Research in conversation analysis has traditionally focused on speakers of English, and it is still unclear to what extent the system observed in that research applies to conversation more generally around the world. However, as this method is now being applied to conversation in a broader range of languages, it is increasingly possible to address questions about the nature of interactional diversity across different speech communities. The approach of pragmatic typology first applies sequential analysis to conversation from different speech communities and then compares interactional patterns in ways analogous to how traditional linguistic typology compares morphosyntax. This article discusses contemporary literature in pragmatic typology, including single-language studies and multilanguage comparisons reflecting both qualitative and quantitative methods. This research finds that microanalysis of face-to-face interaction can identify both universal trends and culture-specific interactional tendencies. Expected final online publication date for the Annual Review of Anthropology, Volume 50 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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