scholarly journals A Study on an Anticyclonic-Cyclonic Eddy Pair Off Fraser Island, Australia

2020 ◽  
Vol 7 ◽  
Author(s):  
Zhibing Li ◽  
Xiaohua Wang ◽  
Jianyu Hu ◽  
Fernando Pinheiro Andutta ◽  
Zhiqiang Liu
Keyword(s):  
Baroclinic Instability ◽  
Three Dimensional ◽  
Dynamic Structure ◽  
Relative Vorticity ◽  
Reanalysis Data ◽  
Cyclonic Eddy ◽  
Generation Stage ◽  
Lagrangian Framework ◽  
Salt Mass ◽  
Dynamic Structures

This research examines a cyclonic-anticyclonic eddy (AE) pair off Fraser Island next to the eastern Australian coast in 2009 using the Bluelink Reanalysis data, where the local eddies are poorly understood. This eddy pair formed in July and dissipated in November. We detailed the horizontal and vertical structures of the eddy pair in terms of three-dimensional variations in relative vorticity, hydrographic properties, velocity, and dynamic structures, which presented notable scales of the eddy pair. The AE formed beside the meandering of the East Australian Current (EAC) at 24°S and had a tilting structure in the upper 1,000 m toward the EAC. A cyclonic eddy (CE) formed a month later and interacted with the AE, which had a tilting structure toward the AE in the upper 1,000 m. Heterogeneity in the AE and CE composing this eddy pair was observed in the horizontal and vertical planes. The AE had a stronger and more coherent dynamic structure than the CE. The AE and the EAC interacted in the generation stage when the EAC path shifted eastward, away from the coast. As the EAC subsequently swung back to the coastal area, the AE and the EAC separated. The AE then interacted with the surrounding eddy fields, propagated westward, before finally merging again with the EAC. The energy transfer during this process also indicated the interactions among the eddy pair, the surrounding eddy fields and the EAC. Baroclinic instability (BCI) was a main contributor to the AE in the generation stage. Barotropic instability (BTI) also contributed energy to the AE when it interacted with the EAC but accounted for a much smaller proportion. Both BCI and BTI contributed to the CE for most of its life cycle but to a much less extend than to the AE. The zonal heat and salt mass transported by the AE and CE were calculated based on a Lagrangian framework method, and these amounts were considerable compared with global zonal averaged heat and salt mass transported by other mesoscale eddies.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

scholarly journals Special Issue: Application of Extracellular Matrix in Regenerative Medicine

2021 ◽  
Vol 11 (7) ◽  
pp. 3262
Author(s):  
Neill J. Turner
Keyword(s):  
Extracellular Matrix ◽  
Regenerative Medicine ◽  
Wound Repair ◽  
Three Dimensional ◽  
Dynamic Structure ◽  
Scaffold Material ◽  
Special Issue ◽  
Organ Regeneration ◽  
Scaffold Materials ◽  
The Many

The present Special Issue comprises a collection of articles addressing the many ways in which extracellular matrix (ECM), or its components parts, can be used in regenerative medicine applications. ECM is a dynamic structure, composed of a three-dimensional architecture of fibrous proteins, proteoglycans, and glycosaminoglycans, synthesized by the resident cells. Consequently, ECM can be considered as nature’s ideal biologic scaffold material. The articles in this Special Issue cover a range of topics from the use of ECM components to manufacture scaffold materials, understanding how changes in ECM composition can lead to the development of disease, and how decellularization techniques can be used to develop tissue-derived ECM scaffolds for whole organ regeneration and wound repair. This editorial briefly summarizes the most interesting aspects of these articles.

scholarly journals Properties of Steady Geostrophic Turbulence with Isopycnal Outcropping

2012 ◽  
Vol 42 (1) ◽  
pp. 18-38 ◽  
Author(s):  
G. Roullet ◽  
J. C. McWilliams ◽  
X. Capet ◽  
M. J. Molemaker
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Mechanical Energy ◽  
Baroclinic Instability ◽  
Three Dimensional ◽  
Primary Source ◽  
Eddy Diffusivity ◽  
Energy Cycle ◽  
Geostrophic Turbulence ◽  
Pv Gradient

Abstract High-resolution simulations of β-channel, zonal-jet, baroclinic turbulence with a three-dimensional quasigeostrophic (QG) model including surface potential vorticity (PV) are analyzed with emphasis on the competing role of interior and surface PV (associated with isopycnal outcropping). Two distinct regimes are considered: a Phillips case, where the PV gradient changes sign twice in the interior, and a Charney case, where the PV gradient changes sign in the interior and at the surface. The Phillips case is typical of the simplified turbulence test beds that have been widely used to investigate the effect of ocean eddies on ocean tracer distribution and fluxes. The Charney case shares many similarities with recent high-resolution primitive equation simulations. The main difference between the two regimes is indeed an energization of submesoscale turbulence near the surface. The energy cycle is analyzed in the (k, z) plane, where k is the horizontal wavenumber. In the two regimes, the large-scale buoyancy forcing is the primary source of mechanical energy. It sustains an energy cycle in which baroclinic instability converts more available potential energy (APE) to kinetic energy (KE) than the APE directly injected by the forcing. This is due to a conversion of KE to APE at the scale of arrest. All the KE is dissipated at the bottom at large scales, in the limit of infinite resolution and despite the submesoscales energizing in the Charney case. The eddy PV flux is largest at the scale of arrest in both cases. The eddy diffusivity is very smooth but highly nonuniform. The eddy-induced circulation acts to flatten the mean isopycnals in both cases.

scholarly journals Ageostrophic Secondary Circulation in a Subtropical Intrathermocline Eddy

2017 ◽  
Vol 47 (5) ◽  
pp. 1107-1123 ◽  
Author(s):  
Bàrbara Barceló-Llull ◽  
Enric Pallàs-Sanz ◽  
Pablo Sangrà ◽  
Antonio Martínez-Marrero ◽  
Sheila N. Estrada-Allis ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Relative Vorticity ◽  
Secondary Circulation ◽  
Vertical Shear ◽  
Propagation Path ◽  
Ekman Pumping ◽  
Centripetal Acceleration ◽  
Omega Equation ◽  
Dipolar Structure ◽  
Upwelling And Downwelling

AbstractVertical motions play a key role in the enhancement of primary production within mesoscale eddies through the introduction of nutrients into the euphotic layer. However, the details of the vertical velocity field w driving these enhancements remain under discussion. For the first time the mesoscale w associated with an intrathermocline eddy is computed and analyzed using in situ high-resolution three-dimensional (3D) fields of density and horizontal velocity by resolving a generalized omega equation valid for high Rossby numbers. In the seasonal pycnocline the diagnosed w reveals a multipolar structure with upwelling and downwelling cells located at the eddy periphery. In the main pycnocline w is characterized by a dipolar structure with downwelling velocities upstream of the propagation path and upwelling velocities downstream. Maximum values of w reach 6.4 m day−1. An observed enhancement of chlorophyll-a at the eddy periphery coincides with the location of the upwelling and downwelling cells. Analysis of the forcing terms of the generalized omega equation indicates that the mechanisms behind the dipolar structure of the w field are a combination of horizontal deformation and advection of vertical relative vorticity by ageostrophic vertical shear. The wind during the eddy sampling was rather constant and uniform with a speed of 5 m s−1. Diagnosed nonlinear Ekman pumping leads to a dipolar pattern that mirrors the inferred w. Horizontal ageostrophic secondary circulation is dominated by centripetal acceleration and closes the dipole w structure. Vertical fluxes act to maintain the intrathermocline eddy structure.

Functional anatomy of atria

ESC CardioMed ◽  
2018 ◽  
pp. 88-92
Author(s):  
Luigi Badano ◽  
Denisa Muraru
Keyword(s):  
Venous Return ◽  
Functional Anatomy ◽  
Three Dimensional ◽  
Volumetric Analysis ◽  
Tissue Imaging ◽  
Integral Role ◽  
Dimensional Echocardiography ◽  
Dynamic Structures ◽  
Three Dimensional Echocardiography ◽  
Ventricular Filling

The left and right atria are dynamic structures that play an integral role in cardiac performance by modulating the respective ventricular filling. This function is accomplished by their role as a reservoir for venous return during ventricular systole, a conduit for venous return during early ventricular diastole, and a booster pump for ventricular filling during late diastole. Recent advances in cardiac imaging allow the accurate assessment of the geometry and phasic functions of both atria. Two- and three-dimensional echocardiography enables a volumetric analysis of atrial function, and both Doppler tissue imaging and speckle-tracking echocardiography allow the assessment of the deformation of atrial myocardium.

scholarly journals The Parcels v2.0 Lagrangian framework: new field interpolation schemes

2019 ◽  
Author(s):  
Philippe Delandmeter ◽  
Erik van Sebille
Keyword(s):  
Three Dimensional ◽  
Analysis Framework ◽  
Interpolation Scheme ◽  
Physical Processes ◽  
North West ◽  
The North ◽  
Lagrangian Framework ◽  
Virtual Particles ◽  
Curvilinear Grids ◽  
Computing Infrastructure

Abstract. With the increasing amount of data produced by numerical ocean models, so increases the need for efficient tools to analyse these data. One of these tools is Lagrangian ocean analysis, where a set of virtual particles are released and their dynamics is integrated in time based on fields defining the ocean state, including the hydrodynamics and biogeochemistry if available. This popular methodology needs to adapt to the large variety of models producing these fields at different formats. This is precisely the aim of Parcels, a Lagrangian ocean analysis framework designed to combine (1) a wide flexibility to model particles of different natures and (2) an efficient implementation in accordance with modern computing infrastructure. In the new Parcels v2.0, we implement a set of interpolation schemes to read various types of discretised fields, from rectilinear to curvilinear grids in the horizontal direction, from z- to s- levels in the vertical and different variable distributions such as the Arakawa's A-, B- and C- grids. In particular, we develop a new interpolation scheme for a three-dimensional curvilinear C-grid and analyse its properties. Parcels v2.0 capabilities, including a suite of meta-field objects, are then illustrated in a brief study of the distribution of floating microplastic in the North West European continental shelf and its sensitivity to different physical processes.

scholarly journals Control-Based 4D Printing: Adaptive 4D-Printed Systems

2020 ◽  
Vol 10 (9) ◽  
pp. 3020 ◽  
Author(s):  
Ali Zolfagharian ◽  
Akif Kaynak ◽  
Mahdi Bodaghi ◽  
Abbas Z. Kouzani ◽  
Saleh Gharaie ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Advanced Manufacturing ◽  
Wearable Electronics ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Control Units ◽  
Printed Sensors ◽  
3D Printed ◽  
Dynamic Structures ◽  
And Control

Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analysed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.

Observations of the dynamic structure of snow avalanches

1993 ◽  
Vol 18 ◽  
pp. 313-316 ◽  
Author(s):  
K. Nishimura ◽  
N. Maeno ◽  
F. Sandersen ◽  
K. Kristensen ◽  
H. Norem ◽  
...  
Keyword(s):  
Dynamic Structure ◽  
Velocity Shear ◽  
Sensor Data ◽  
Video Tape ◽  
Snow Avalanches ◽  
Western Norway ◽  
Wet Snow ◽  
Avalanche Flow ◽  
Dynamic Structures ◽  
Internal Velocity

During two winters, 1990–92, the dynamic structures of snow avalanches were studied in western Norway. Artificially released wet-snow avalanches ran down the avalanche chute and stopped in front of the retaining dam. Running velocity distributions were obtained not only by video tape recorder, but also by various other recording instruments. Internal velocity was derived for the last avalanche by frequency analysis of impact pressure and optical sensor data. The vertical velocity shear of the avalanche flow has been estimated to be in the range 1–10 s−1.

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