Mass Transfer at the Ocean–Atmosphere Interface: The Role of Wave Breaking, Droplets, and Bubbles

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Luc Deike
Keyword(s):  
Wave Breaking ◽  
Cloud Condensation Nuclei ◽  
Breaking Waves ◽  
Sea Spray ◽  
Annual Review ◽  
Publication Date ◽  
Length Scales ◽  
Air Bubble ◽  
Wide Range ◽  
Controlling Processes

Breaking waves modulate the transfer of energy, momentum, and mass between the ocean and atmosphere, controlling processes critical to the climate system, from gas exchange of carbon dioxide and oxygen to the generation of sea spray aerosols that can be transported in the atmosphere and serve as cloud condensation nuclei. The smallest components, i.e., drops and bubbles generated by breaking waves, play an outsize role. This fascinating problem is characterized by a wide range of length scales, from wind forcing the wave field at scales of 𝒪(1 km–0.1 m) to the dynamics of wave breaking at 𝒪(10–0.1 m); air bubble entrainment, dynamics, and dissolution in the water column at 𝒪(1 m–10 μm); and bubbles bursting at 𝒪(10 mm–1 μm), generating sea spray droplets at 𝒪(0.5 mm–0.5 μm) that are ejected into atmospheric turbulent boundary layers. I discuss recent progress to bridge these length scales, identifying the controlling processes and proposing a path toward mechanistic parameterizations of air–sea mass exchange that naturally accounts for sea state 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 The Fracture of Highly Deformable Soft Materials: A Tale of Two Length Scales

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Rong Long ◽  
Chung-Yuen Hui ◽  
Jian Ping Gong ◽  
Eran Bouchbinder
Keyword(s):  
Practical Importance ◽  
Soft Materials ◽  
Annual Review ◽  
Publication Date ◽  
Stretchable Electronics ◽  
Length Scales ◽  
Theoretical Concepts ◽  
Strongly Nonlinear ◽  
Wide Range ◽  
Basic Physics

The fracture of highly deformable soft materials is of great practical importance in a wide range of technological applications, emerging in fields such as soft robotics, stretchable electronics, and tissue engineering. From a basic physics perspective, the failure of these materials poses fundamental challenges due to the strongly nonlinear and dissipative deformation involved. In this review, we discuss the physics of cracks in soft materials and highlight two length scales that characterize the strongly nonlinear elastic and dissipation zones near crack tips in such materials. We discuss physical processes, theoretical concepts, and mathematical results that elucidate the nature of the two length scales and show that the two length scales can classify a wide range of materials. The emerging multiscale physical picture outlines the theoretical ingredients required for the development of predictive theories of the fracture soft materials. We conclude by listing open challenges and future investigation directions. Expected final online publication date for the Annual Review of Condensed Matter Physics, Volume 12 is March 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Basis of Navigation Across Species

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Cody A. Freas ◽  
Ken Cheng
Keyword(s):  
Large Scale ◽  
Error Reduction ◽  
Annual Review ◽  
Publication Date ◽  
Additional Component ◽  
Oscillatory Systems ◽  
Neural Architecture ◽  
Wide Range ◽  
Reduction Strategies ◽  
Cycling Behavior

Animals navigate a wide range of distances, from a few millimeters to globe-spanning journeys of thousands of kilometers. Despite this array of navigational challenges, similar principles underlie these behaviors across species. Here, we focus on the navigational strategies and supporting mechanisms in four well-known systems: the large-scale migratory behaviors of sea turtles and lepidopterans as well as navigation on a smaller scale by rats and solitarily foraging ants. In lepidopterans, rats, and ants we also discuss the current understanding of the neural architecture which supports navigation. The orientation and navigational behaviors of these animals are defined in terms of behavioral error-reduction strategies reliant on multiple goal-directed servomechanisms. We conclude by proposing to incorporate an additional component into this system: the observation that servomechanisms operate on oscillatory systems of cycling behavior. These oscillators and servomechanisms comprise the basis for directed orientation and navigational behaviors. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Engineering Advances in Spray Drying for Pharmaceuticals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
John M. Baumann ◽  
Molly S. Adam ◽  
Joel D. Wood
Keyword(s):  
Spray Drying ◽  
Oral Delivery ◽  
Process Development ◽  
Solid Dispersions ◽  
Amorphous Solid ◽  
Annual Review ◽  
Publication Date ◽  
Dry Powders ◽  
Wide Range ◽  
Pharmaceutical Industries

Spray drying is a versatile technology that has been applied widely in the chemical, food, and, most recently, pharmaceutical industries. This review focuses on engineering advances and the most significant applications of spray drying for pharmaceuticals. An in-depth view of the process and its use is provided for amorphous solid dispersions, a major, growing drug-delivery approach. Enhanced understanding of the relationship of spray-drying process parameters to final product quality attributes has made robust product development possible to address a wide range of pharmaceutical problem statements. Formulation and process optimization have leveraged the knowledge gained as the technology has matured, enabling improved process development from early feasibility screening through commercial applications. Spray drying's use for approved small-molecule oral products is highlighted, as are emerging applications specific to delivery of biologics and non-oral delivery of dry powders. Based on the changing landscape of the industry, significant future opportunities exist for pharmaceutical spray drying. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 12 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Chemical Stability of Proteins in Foods: Oxidation and the Maillard Reaction

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mahesha M. Poojary ◽  
Marianne N. Lund
Keyword(s):  
Maillard Reaction ◽  
Protein Oxidation ◽  
Oxidation Products ◽  
Protein Carbonyls ◽  
Annual Review ◽  
Publication Date ◽  
Food Protein ◽  
Food Proteins ◽  
Wide Range ◽  
Specific Oxidation

Protein is a major nutrient present in foods along with carbohydrates and lipids. Food proteins undergo a wide range of modifications during food production, processing, and storage. In this review, we discuss two major reactions, oxidation and the Maillard reaction, involved in chemical modifications of food proteins. Protein oxidation in foods is initiated by metal-, enzyme-, or light-induced processes. Food protein oxidation results in the loss of thiol groups and the formation of protein carbonyls and specific oxidation products of cysteine, tyrosine, tryptophan, phenylalanine, and methionine residues, such as disulfides, dityrosine, kynurenine, m-tyrosine, and methionine sulfoxide. The Maillard reaction involves the reaction of nucleophilic amino acid residues with reducing sugars, which yields numerous heterogeneous compounds such as α-dicarbonyls, furans, Strecker aldehydes, advanced glycation end-products, and melanoidins. Both protein oxidation and the Maillard reaction result in the loss of essential amino acids but may positively or negatively impact food structure and flavor. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Freshwater Scarcity

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Peter H. Gleick ◽  
Heather Cooley
Keyword(s):  
Fresh Water ◽  
Water Scarcity ◽  
Sustainable Management ◽  
Ecosystem Health ◽  
Annual Review ◽  
Publication Date ◽  
Wide Range ◽  
Use Efficiency ◽  
Alternative Sources ◽  
Violent Conflicts

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natural freshwater availability is contributing to water scarcity, affecting industrial and agricultural production and a wide range of social, economic, and political problems, including poverty, deterioration of ecosystem health, and violent conflicts. Understanding and addressing different forms of water scarcity are vital for moving toward more sustainable management and use of fresh water. We provide here a review of concepts and definitions of water scarcity, metrics and indicators used to evaluate scarcity together with strategies for addressing and reducing the adverse consequences of water scarcity, including the development of alternative sources of water, improvements in water-use efficiency, and changes in systems of water management and planning. Expected final online publication date for the Annual Review of Environment and Resources, Volume 46 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Neural Network Potentials: A Concise Overview of Methods

2022 ◽  
Vol 73 (1) ◽  
Author(s):  
Emir Kocer ◽  
Tsz Wai Ko ◽  
Jörg Behler
Keyword(s):  
Machine Learning ◽  
Atomic Structure ◽  
Electrostatic Interactions ◽  
Large Scale ◽  
Machine Learning Algorithms ◽  
Annual Review ◽  
Publication Date ◽  
Great Success ◽  
Concise Overview ◽  
Wide Range

In the past two decades, machine learning potentials (MLPs) have reached a level of maturity that now enables applications to large-scale atomistic simulations of a wide range of systems in chemistry, physics, and materials science. Different machine learning algorithms have been used with great success in the construction of these MLPs. In this review, we discuss an important group of MLPs relying on artificial neural networks to establish a mapping from the atomic structure to the potential energy. In spite of this common feature, there are important conceptual differences among MLPs, which concern the dimensionality of the systems, the inclusion of long-range electrostatic interactions, global phenomena like nonlocal charge transfer, and the type of descriptor used to represent the atomic structure, which can be either predefined or learnable. A concise overview is given along with a discussion of the open challenges in the field. 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.

scholarly journals First air–sea gas exchange laboratory study at hurricane wind speeds

2013 ◽  
Vol 10 (6) ◽  
pp. 1971-1996
Author(s):  
K. E. Krall ◽  
B. Jähne
Keyword(s):  
Wave Breaking ◽  
High Speed ◽  
Wind Wave ◽  
Breaking Waves ◽  
Gas Transfer ◽  
Transfer Velocity ◽  
Wind Speeds ◽  
Hurricane Wind ◽  
Wide Range ◽  
Enhanced Surface

Abstract. In a pilot study conducted in October and November 2011, air–sea gas transfer velocities of the two sparingly soluble trace gases hexafluorobenzene and 1,4-difluorobenzene were measured in the unique High-Speed Wind-Wave Tank at Kyoto University, Japan. This air–sea interaction facility is capable of producing hurricane strength wind speeds of up to u10=67 m s−1. This constitutes the first lab study of gas transfer at such high wind speeds. The measured transfer velocities k600 spanned two orders of magnitude, lying between 11 cm h−1 and 1180 cm h−1 with the latter being the highest ever measured wind induced gas transfer velocity. The measured gas transfer velocities are in agreement with the only available dataset at hurricane wind speeds (McNeil and D'Asaro, 2007). The disproportionately large increase of the transfer velocities found at highest wind speeds indicates a new regime of air–sea gas transfer, which is characterized by strong wave breaking, enhanced turbulence and bubble cloud entrainment. It was found that tracers spanning a wide range of solubilities and diffusivities are needed to separate the effects of enhanced surface area and turbulence due to breaking waves from the effects of bubble and spray mediated gas transfer.

scholarly journals Score-Driven Time Series Models

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrew C. Harvey
Keyword(s):  
Time Series ◽  
Circular Data ◽  
Annual Review ◽  
Time Series Models ◽  
Publication Date ◽  
Time Series Modeling ◽  
Dynamic Correlation ◽  
Switching Regimes ◽  
Wide Range ◽  
Application Volume

The construction of score-driven filters for nonlinear time series models is described, and they are shown to apply over a wide range of disciplines. Their theoretical and practical advantages over other methods are highlighted. Topics covered include robust time series modeling, conditional heteroscedasticity, count data, dynamic correlation and association, censoring, circular data, and switching regimes. Expected final online publication date for the Annual Review of Statistics and Its Application, Volume 9 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dynamics of Atrial Fibrillation Mechanisms and Comorbidities

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Jordi Heijman ◽  
Dominik Linz ◽  
Ulrich Schotten
Keyword(s):  
Risk Factors ◽  
Atrial Fibrillation ◽  
Clinical Practice ◽  
Dynamic Interaction ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
Atrial Remodeling ◽  
Dynamic Changes ◽  
Wide Range

Atrial fibrillation (AF) contributes to morbidity and mortality of millions of individuals. Its molecular, cellular, neurohumoral, and hemodynamic pathophysiological mechanisms are complex, and there is increasing awareness that a wide range of comorbidities can contribute to AF-promoting atrial remodeling. Moreover, recent research has highlighted that AF risk is not constant and that the temporal variation in concomitant conditions contributes to the complexity of AF dynamics. In this review, we provide an overview of fundamental AF mechanisms related to established and emerging comorbidities or risk factors and their role in the AF-promoting effects. We focus on the accumulating evidence for the relevance of temporally dynamic changes in these risk factors and the consequence for AF initiation and maintenance. Finally, we highlight the important implications for future research and clinical practice resulting from the dynamic interaction between AF risk factors and mechanisms. Expected final online publication date for the Annual Review of Physiology, Volume 83 is February 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation

2010 ◽  
Vol 40 (9) ◽  
pp. 1917-1941 ◽  
Author(s):  
Fabrice Ardhuin ◽  
Erick Rogers ◽  
Alexander V. Babanin ◽  
Jean-François Filipot ◽  
Rudy Magne ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
Wave Breaking ◽  
Wave Spectrum ◽  
Remote Sensing Data ◽  
Ocean Waves ◽  
Breaking Waves ◽  
Global Ocean ◽  
Short Waves ◽  
Wide Range

Abstract New parameterizations for the spectral dissipation of wind-generated waves are proposed. The rates of dissipation have no predetermined spectral shapes and are functions of the wave spectrum and wind speed and direction, in a way consistent with observations of wave breaking and swell dissipation properties. Namely, the swell dissipation is nonlinear and proportional to the swell steepness, and dissipation due to wave breaking is nonzero only when a nondimensional spectrum exceeds the threshold at which waves are observed to start breaking. An additional source of short-wave dissipation is introduced to represent the dissipation of short waves due to longer breaking waves. A reduction of the wind-wave generation of short waves is meant to account for the momentum flux absorbed by longer waves. These parameterizations are combined and calibrated with the discrete interaction approximation for the nonlinear interactions. Parameters are adjusted to reproduce observed shapes of directional wave spectra, and the variability of spectral moments with wind speed and wave height. The wave energy balance is verified in a wide range of conditions and scales, from the global ocean to coastal settings. Wave height, peak and mean periods, and spectral data are validated using in situ and remote sensing data. Some systematic defects are still present, but, overall, the parameterizations probably yield the most accurate estimates of wave parameters to date. Perspectives for further improvement are also given.

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