scholarly journals Vortex Dipoles for Surface Quasigeostrophic Models

2007 ◽  
Vol 64 (8) ◽  
pp. 2961-2967 ◽  
Author(s):  
David J. Muraki ◽  
Chris Snyder
Keyword(s):  
Temperature Gradient ◽  
Potential Temperature ◽  
Three Dimensional ◽  
Phase Speed ◽  
Vertical Shear ◽  
Edge Waves ◽  
New Class ◽  
Vortex Dipoles ◽  
Vortex Dipole ◽  
Uniform Background

A new class of exact vortex dipole solutions is derived for surface quasigeostrophic (sQG) models. The solutions extend the two-dimensional barotropic modon to fully three-dimensional, continuously stratified flow and are a simple model of localized jets on the tropopause. In addition to the basic sQG dipole, dipole structures exist for a layer of uniform potential vorticity between two rigid boundaries and for a dipole in the presence of uniform background vertical shear and horizontal potential temperature gradient. In the former case, the solution approaches the barotropic Lamb dipole in the limit of a layer that is shallow relative to the Rossby depth based on the dipole’s radius. In the latter case, dipoles that are bounded in the far field must propagate counter to the phase speed of the linear edge waves associated with the surface temperature gradient.

The origin of the stationary frontal wave packet spontaneously generated in rotating stratified vortex dipoles

2007 ◽  
Vol 593 ◽  
pp. 359-383 ◽  
Author(s):  
ÁLVARO VIÚDEZ
Keyword(s):  
Wave Packet ◽  
Vertical Velocity ◽  
Large Scale ◽  
Three Dimensional ◽  
Rate Of Change ◽  
Vertical Shear ◽  
Dipole Axis ◽  
Frontal Wave ◽  
Vortex Dipoles ◽  
Vorticity Vector

The origin of the stationary frontal wave packet spontaneously generated in rotating and stably stratified vortex dipoles is investigated through high-resolution three-dimensional numerical simulations of non-hydrostatic volume-preserving flow under the f-plane and Boussinesq approximations. The wave packet is rendered better at mid-depths using ageostrophic quantities like the vertical velocity or the vertical shear of the ageostrophic vertical vorticity. The analysis of the origin of vertical velocity anomalies in shallow layers using the generalized omega-equation reveals that these anomalies are related to the material rate of change of the ageostrophic differential vorticity, which in shallow layers are themselves related to the large-scale ageostrophic flow along the dipole axis, and in particular, to the advective acceleration. It is found that on the anticyclonic side of the dipole axis the combined effect of the speed and centripetal accelerations causes an anticyclonic rotation of the horizontal ageostrophic vorticity vector in a time scale of about one inertial period. These facts support the hypothesis that the origin of the stationary and spontaneously generated frontal wave packet at mid-depths is the large acceleration of the fluid particles as they move along the anticyclonic side of the dipole axis in shallow layers.

scholarly journals Motion and structure of atmospheric mesoscale baroclinic vortices: dry air and weak environmental shear

2012 ◽  
Vol 701 ◽  
pp. 137-170 ◽  
Author(s):  
Eileen Päschke ◽  
Patrik Marschalik ◽  
Antony Z. Owinoh ◽  
Rupert Klein
Keyword(s):  
Evolution Equations ◽  
Potential Temperature ◽  
Three Dimensional ◽  
Present Theory ◽  
Vertical Shear ◽  
Order Unity ◽  
Dry Air ◽  
Wind Speeds ◽  
Axisymmetric Vortex ◽  
Baroclinic Vortices

AbstractA strongly tilted, nearly axisymmetric vortex in dry air with asymmetric diabatic heating is analysed here by matched asymptotic expansions. The vortex is in gradient wind balance, with vortex Rossby numbers of order unity, and embedded in a quasi-geostrophic (QG) background wind with weak vertical shear. With wind speeds of $60{{\ndash}}120~\mathrm{km} ~{\mathrm{h} }^{\ensuremath{-} 1} $, such vortices correspond to tropical storms or nascent hurricanes according to the Saffir–Simpson scale. For asymmetric heating, nonlinear coupling of the evolution equations for the vortex tilt, its core structure, and its influence on the QG background is found. The theory compares well with the established linear theory of precessing quasi-modes of atmospheric vortices, and it corroborates the relationship between vortex tilt and asymmetric potential temperature and vertical velocity patterns as found by Jones (Q. J. R. Meteorol. Soc., vol. 121, 1995, pp. 821–851) and Frank & Ritchie (Mon. Weath. Rev., vol. 127, 1999, pp. 2044–2061) in simulations of adiabatic tropical cyclones. A relation between the present theory and the local induction approximation for three-dimensional slender vortex filaments is established.

A Peptoid with Extended Shape in Water

2019 ◽  
Author(s):  
Jumpei Morimoto ◽  
Yasuhiro Fukuda ◽  
Takumu Watanabe ◽  
Daisuke Kuroda ◽  
Kouhei Tsumoto ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Biomolecular Recognition ◽  
Biological Application ◽  
New Class ◽  
Proteolytic Resistance ◽  
Pharmacokinetic Properties ◽  
Optically Pure ◽  
Three Dimensional Space

<div> <div> <div> <p>“Peptoids” was proposed, over decades ago, as a term describing analogs of peptides that exhibit better physicochemical and pharmacokinetic properties than peptides. Oligo-(N-substituted glycines) (oligo-NSG) was previously proposed as a peptoid due to its high proteolytic resistance and membrane permeability. However, oligo-NSG is conformationally flexible and is difficult to achieve a defined shape in water. This conformational flexibility is severely limiting biological application of oligo-NSG. Here, we propose oligo-(N-substituted alanines) (oligo-NSA) as a new peptoid that forms a defined shape in water. A synthetic method established in this study enabled the first isolation and conformational study of optically pure oligo-NSA. Computational simulations, crystallographic studies and spectroscopic analysis demonstrated the well-defined extended shape of oligo-NSA realized by backbone steric effects. The new class of peptoid achieves the constrained conformation without any assistance of N-substituents and serves as an ideal scaffold for displaying functional groups in well-defined three-dimensional space, which leads to effective biomolecular recognition. </p> </div> </div> </div>

scholarly journals A THREE DIMENSIONAL MODEL OF THE GULF OF ALASKA

1986 ◽  
Vol 1 (20) ◽  
pp. 193 ◽  
Author(s):  
Shiao-Kung Liu ◽  
Jan J. Leendertse
Keyword(s):  
Three Dimensional ◽  
Gulf Of Alaska ◽  
Vertical Shear ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Weather Model ◽  
Closure Scheme ◽  
Vertical Grid ◽  
Northern Pacific ◽  
Horizontal Grid

This paper presents the development of a three dimensional model of the Gulf of Alaska. The model extends between the Vancouver Island and the Aleutian Islands covering approximatedly 1.5 million square kilometers over the northern Pacific Ocean. Formulated on an ellipsoidal horizontal grid and variable vertical grid, the model is schematized over a 81 x 53 x 10 grid structure. The solution scheme is implicit over the vertical and is programmed using one-dimensional dynamic array for the efficient use of machine storage. The turbulence closure scheme for the non-homogeneous vertical shear is formulated so that the potential and kinetic energetics are monitored and transferred in a closed form. The hydrodynamic model is coupled to a two-dimensional stochastic weather model and an oil-spill trajectory/weathering model. The former also simulates stochastically the cyclogenetic/cyclolytic processes within the modeled area. The paper also compares the computed results with the available field data. Good agreements are found in tidal amplitude and phases as well as currents.

A three-dimensional hierarchical Fe2O3@NiO core/shell nanorod array on carbon cloth: a new class of anode for high-performance lithium-ion batteries

Nanoscale ◽  
2013 ◽  
Vol 5 (17) ◽  
pp. 7906 ◽  
Author(s):  
Qin-qin Xiong ◽  
Jiang-ping Tu ◽  
Xin-hui Xia ◽  
Xu-yang Zhao ◽  
Chang-dong Gu ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
High Performance ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Nanorod Array ◽  
Core Shell ◽  
Carbon Cloth ◽  
New Class

Thermal Stresses in Moderately Thick Elastic Plates

1959 ◽  
Vol 26 (3) ◽  
pp. 432-436
Author(s):  
B. E. Gatewood
Keyword(s):  
Temperature Gradient ◽  
Plane Stress ◽  
Thermal Stresses ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Elastic Plates ◽  
Plate Length ◽  
Moderately Thick Plates ◽  
Thick Elastic Plates ◽  
Thickness Variable

Abstract The three-dimensional stresses in the plate are investigated without using the plane-stress or plane-strain assumptions, the thickness of the plate being limited so that the normal stress in the thickness direction can be taken as a polynomial in the thickness variable. The temperature is taken as a polynomial in the thickness variable but with relatively large, though restricted, gradients with respect to the co-ordinates of the plane of the plate. For the case of the temperature constant in thickness variable, the stresses in the plane of the plate are presented as the plane-stress solution plus correcting terms due to the plate thickness, where the correcting terms involve the product of the temperature gradient and the ratio of the plate thickness to the plate length in the direction of the temperature gradient. In many cases the corrections are small even for moderately thick plates.

scholarly journals Simulation of denitrification and ozone loss for the Arctic winter 2002/2003

2005 ◽  
Vol 5 (6) ◽  
pp. 1437-1448 ◽  
Author(s):  
J.-U. Grooß ◽  
G. Günther ◽  
R. Müller ◽  
P. Konopka ◽  
S. Bausch ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Potential Temperature ◽  
Three Dimensional ◽  
Lagrangian Model ◽  
The Arctic ◽  
Particle Nucleation ◽  
Ozone Loss ◽  
Dimensional Version ◽  
Total Inorganic Nitrogen ◽  
Catalytic Cycles

Abstract. We present simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the Arctic winter 2002/2003. We integrated a Lagrangian denitrification scheme into the three-dimensional version of CLaMS that calculates the growth and sedimentation of nitric acid trihydrate (NAT) particles along individual particle trajectories. From those, we derive the HNO3 downward flux resulting from different particle nucleation assumptions. The simulation results show a clear vertical redistribution of total inorganic nitrogen ( ), with a maximum vortex average permanent removal of over 5ppb in late December between 500 and 550K and a corresponding increase of of over 2ppb below about 450K. The simulated vertical redistribution of is compared with balloon observations by MkIV and in-situ observations from the high altitude aircraft Geophysica. Assuming a globally uniform NAT particle nucleation rate of 7.8x10-6cm-3h-1 in the model, the observed denitrification is well reproduced. In the investigated winter 2002/2003, the denitrification has only moderate impact (≤14%) on the simulated vortex average ozone loss of about 1.1ppm near the 460K level. At higher altitudes, above 600K potential temperature, the simulations show significant ozone depletion through -catalytic cycles due to the unusual early exposure of vortex air to sunlight.

A hydrostable and twofold interpenetrating three-dimensional zinc–organic framework with rob topology based on 4,4′-oxydibenzoate and 3,3′-dimethyl-4,4′-bipyridine ligands

2016 ◽  
Vol 72 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Feng-Lan Liang ◽  
De-Yun Ma ◽  
Liang Qin
Keyword(s):  
Title Compound ◽  
Three Dimensional ◽  
New Class ◽  
Pyramidal Geometry ◽  
Potential Applications ◽  
Metal Organic ◽  
Ph Range ◽  
Square Pyramidal Geometry ◽  
Bright Blue Fluorescence ◽  
Bright Blue

Metal–organic frameworks (MOFs) are a new class of porous materials that have received widespread attention due to their potential applications in gas storage and/or separation, catalysis, luminescence, and so on. The title compound, poly[[(μ2-3,3′-dimethyl-4,4′-bipyridine-κ2N:N′)bis(μ4-4,4′-oxydibenzoato-κ4O:O′:O′′:O′′′)dizinc] tetrahydrate], {[Zn2(C14H8O5)2(C12H12N2)]·4H2O}n, has been prepared by the solvothermal assembly of Zn(NO3)2·6H2O, 4,4′-oxydi(benzoic acid) and 3,3′-dimethyl-4,4′-bipyridine. The two ZnIIatoms adopt the same five-coordinated distorted square-pyramidal geometry (i.e.ZnO4N), bonding to four O atoms from four different 4,4′-oxydibenzoate (oba) ligands and one N atom from a 3,3′-dimethyl-4,4′-bipyridine (dmbpy) ligand. The supramolecular secondary building unit (SBU) is a paddle-wheel [Zn2(COO)4] unit and these units are linked by oba ligands within the layer to form a two-dimensional net parallel to thebaxis, with the dmbpy ligands pointing alternately up and down, which is further extended by dmbpy ligands to form a three-dimensional framework withrobtopology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K and is stable in aqueous solutions in the pH range 5–9. Excitation and luminescence data observed at room temperature show that it emits a bright-blue fluorescence.

Heat Transport by Countercurrent Blood Vessels in the Presence of an Arbitrary Temperature Gradient

1990 ◽  
Vol 112 (2) ◽  
pp. 207-211 ◽  
Author(s):  
J. W. Baish
Keyword(s):  
Thermal Conductivity ◽  
Temperature Gradient ◽  
Vascular Tissue ◽  
Asymptotic Methods ◽  
Three Dimensional ◽  
Conductive Materials ◽  
Arbitrary Temperature ◽  
The Mean ◽  
Conductive Fibers ◽  
Arteries And Veins

This paper presents a three-dimensional analysis of the temperature field around a pair of countercurrent arteries and veins embedded in an infinite tissue that has an arbitrary temperature gradient along the axes of the vessels. Asymptotic methods are used to show that such vessels are thermally similar to a highly conductive fiber in the same tissue. Expressions are developed for the effective radius and thermal conductivity of the fiber so that it conducts heat at the same rate that the artery and vein together convect heat and so that its local temperature equals the mean temperature of the vessels. This result allows vascular tissue to be viewed as a composite of conductive materials with highly conductive fibers replacing the convective effects of the vasculature. By characterizing the size and thermal conductivity of these fibers, well-established methods from the study of composites may be applied to determine when an effective conductive model is appropriate for the tissue and vasculature as a whole.

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