The Propagation Mechanism of a Vortex on the β Plane

2007 ◽  
Vol 37 (9) ◽  
pp. 2316-2330 ◽  
Author(s):  
Peter Jan van Leeuwen
Keyword(s):  
Coriolis Force ◽  
Opposite Sign ◽  
Propagation Mechanism ◽  
Reduced Gravity ◽  
Background Current ◽  
Background Flow ◽  
Coriolis Parameter ◽  
First Order ◽  
Flow Changes

Abstract The propagation velocity and propagation mechanism for vortices on a β plane are determined for a reduced-gravity model by integrating the momentum equations over the β plane. Isolated vortices, vortices in a background current, and initial vortex propagation from rest are studied. The propagation mechanism for isolated anticyclones as well as cyclones, which has been lacking up to now, is presented. It is shown that, to first order, the vortex moves to generate a Coriolis force on the mass anomaly of the vortex to compensate for the force on the vortex due to the variation of the Coriolis parameter. Only the mass anomaly of the vortex is of importance, because the Coriolis force due to the motion of the bulk of the layer moving with the vortex is almost fully compensated by the Coriolis force on the motion of the exterior flow. Because the mass anomaly of a cyclone is negative the force and acceleration have opposite sign. The role of dipolar structures in steadily moving vortices is discussed, and it is shown that their overall structure is fixed by the steady westward motion of the mass anomaly. Furthermore, it is shown that reduced-gravity vortices are not advected with a background flow. The reason for this behavior is that the background flow changes the ambient vorticity gradient such that the vortex obtains an extra self-propagation term that exactly cancels the advection by the background flow. Last, it is shown that a vortex initially at rest will accelerate equatorward first, after which a westward motion is generated. This result is independent of the sign of the vortex.

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

scholarly journals Ganglioside incorporation and release by the isolated perfused rat liver

1991 ◽  
Vol 274 (2) ◽  
pp. 581-585 ◽  
Author(s):  
S C Kivatinitz ◽  
A Miglio ◽  
R Ghidoni
Keyword(s):  
Rat Liver ◽  
The Other ◽  
Regulatory Role ◽  
Isolated Perfused Rat Liver ◽  
Order Kinetic ◽  
Perfused Rat Liver ◽  
Ganglioside Gm1 ◽  
First Order ◽  
Pseudo First Order

The fate of exogenous ganglioside GM1 labelled in the sphingosine moiety, [Sph-3H]GM1, administered as a pulse, in the isolated perfused rat liver was investigated. When a non-recirculating protocol was employed, the amount of radioactivity in the liver and perfusates was found to be dependent on the presence of BSA in the perfusion liquid and on the time elapsed after the administration of the ganglioside. When BSA was added to the perfusion liquid, less radioactivity was found in the liver and more in the perfusate at each time tested, for up to 1 h. The recovery of radioactivity in the perfusates followed a complex course which can be described by three pseudo-first-order kinetic constants. The constants, in order of decreasing velocity, are interpreted as: (a) the dilution of the labelled GM1 by the constant influx of perfusion liquid; (b) the washing off of GM1 loosely bound to the surface of liver cells; (c) the release of gangliosides from the liver. Process (b) was found to be faster in the presence of BSA, probably owing to the ability of BSA to bind gangliosides. The [Sph-3H]GM1 in the liver underwent metabolism, leading to the appearance of products of anabolic (GD1a, GD1b) and catabolic (GM2, GM3) origin; GD1a appeared before GM2 and GM3 but, at times longer than 10 min, GM2 and GM3 showed more radioactivity than GD1a. At a given time the distribution of the radioactivity in the perfusates was quite different from that of the liver. In fact, after 60 min GD1a was the only metabolite present in any amount, the other being GM3, the quantity of which was small. This indicates that the liver is able to release newly synthesized gangliosides quite specifically. When a recirculating protocol was used, there were more catabolites and less GD1a than with the non-recirculating protocol. A possible regulatory role of ganglioside re-internalization on their own metabolism in the liver is postulated.

On the role of Ramsey quantifiers in first order arithmetic

1982 ◽  
Vol 47 (2) ◽  
pp. 423-435 ◽  
Author(s):  
James H. Schmerl ◽  
Stephen G. Simpson
Keyword(s):  
Formal System ◽  
Intended Meaning ◽  
Completeness Proof ◽  
First Order ◽  
Uncountable Cardinal ◽  
Consistent Extension ◽  
Witness Set ◽  
Order Arithmetic ◽  
Infinite Set

The purpose of this paper is to study a formal system PA(Q2) of first order Peano arithmetic, PA, augmented by a Ramsey quantifier Q2 which binds two free variables. The intended meaning of Q2xx′φ(x, x′) is that there exists an infinite set X of natural numbers such that φ(a, a′) holds for all a, a′ Є X such that a ≠ a′. Such an X is called a witness set for Q2xx′φ(x, x′). Our results would not be affected by the addition of further Ramsey quantifiers Q3, Q4, …, Here of course the intended meaning of Qkx1 … xkφ(x1,…xk) is that there exists an infinite set X such that φ(a1…, ak) holds for all k-element subsets {a1, … ak} of X.Ramsey quantifiers were first introduced in a general model theoretic setting by Magidor and Malitz [13]. The system PA{Q2), or rather, a system essentially equivalent to it, was first defined and studied by Macintyre [12]. Some of Macintyre's results were obtained independently by Morgenstern [15]. The present paper is essentially self-contained, but all of our results have been directly inspired by those of Macintyre [12].After some preliminaries in §1, we begin in §2 by giving a new completeness proof for PA(Q2). A by-product of our proof is that for every regular uncountable cardinal k, every consistent extension of PA(Q2) has a k-like model in which all classes are definable. (By a class we mean a subset of the universe of the model, every initial segment of which is finite in the sense of the model.)

Role of Single Word Variables in Recall of Statistical Approximations to English

1966 ◽  
Vol 19 (2) ◽  
pp. 627-634 ◽  
Author(s):  
Mari J. K. Brown
Keyword(s):  
Free Recall ◽  
Higher Order ◽  
Order Of Approximation ◽  
Single Word ◽  
First Order ◽  
Original Order ◽  
Sequential Organization ◽  
The Individual

Free recall of lists at different orders of approximation to English was compared to the recall of the same lists when the order of the words had been scrambled to destroy their sequential organization. Recall of the organized lists showed the typical improvement with increasing order of approximation. Recall of the scrambled lists was unrelated to the original order of approximation. The results indicate that increased recall with increasing order of approximation to English is not produced by systematic differences in the characteristics of the individual words comprising the approximations. When recall of the organized lists was scored in terms of the number of longer sequences present in recall, the number of recalled sequences of any given length increased as order of approximation to English increased, with the first order list showing proportionally less organization in recall than the second and higher order lists.

scholarly journals Reasoning with Time Intervals: A Logical and Computational Perspective

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Guido Sciavicco
Keyword(s):  
Temporal Reasoning ◽  
Point Of View ◽  
Time Intervals ◽  
First Order ◽  
Modal Interval ◽  
The Family ◽  
First Results ◽  
Comprehensive Survey ◽  
Classical Point

The role of time in artificial intelligence is extremely important. Interval-based temporal reasoning can be seen as a generalization of the classical point-based one, and the first results in this field date back to Hamblin (1972) and Benhtem (1991) from the philosophical point of view, to Allen (1983) from the algebraic and first-order one, and to Halpern and Shoham (1991) from the modal logic one. Without purporting to provide a comprehensive survey of the field, we take the reader to a journey through the main developments in modal and first-order interval temporal reasoning over the past ten years and outline some landmark results on expressiveness and (un)decidability of the satisfiability problem for the family of modal interval logics.

The role of gravity in the motion of plasma arcs inside ‘Plasma Balls’: An investigation in the NASA reduced gravity student flight opportunities program

2006 ◽  
Vol 18 (2) ◽  
pp. 39-43
Author(s):  
B. Zoltowski ◽  
K. Leard ◽  
N. Carter ◽  
K. Budzinski ◽  
W. Ainsworth ◽  
...  
Keyword(s):  
Reduced Gravity

Pharmacological Data and Technical Feasibility of Intraperitoneal 5-Fluorouracil Administration

1982 ◽  
Vol 68 (5) ◽  
pp. 437-441 ◽  
Author(s):  
Romano Demicheli ◽  
Antonio Jirillo ◽  
Giorgio Bonciarelli ◽  
Anna Bellini ◽  
Luigi Petrosino ◽  
...  
Keyword(s):  
Malignant Disease ◽  
Technical Feasibility ◽  
Order Function ◽  
Drug Levels ◽  
Tenckhoff Catheter ◽  
Plasma Ratio ◽  
First Order ◽  
Concentration Time ◽  
Pharmacological Data

Via a surgically implanted Tenckhoff catheter, 5-fluorouracil was intraperitoneally administered to patients with malignant disease confined to abdominal space. Treatment was well tolerated without local complications. Peritoneal and plasmatic drug levels were measured, showing that: 1) peritoneal drug levels declined as a first order function; 2) plasmatic levels were very close to those reported for continuous i.v. administration, but peritoneal concentrations were much higher (log 1 to 3); 3) concentration × time product had a peritoneum: plasma ratio ranging from 120 to 1350. The hypothesized role of intraperitoneal 5-fluorouracil administration and the questions still to be answered are summarized.

Acoustic Features of Rhesus Vocalizations and Their Representation in the Ventrolateral Prefrontal Cortex

2007 ◽  
Vol 97 (2) ◽  
pp. 1470-1484 ◽  
Author(s):  
Yale E. Cohen ◽  
Frédéric Theunissen ◽  
Brian E. Russ ◽  
Patrick Gill
Keyword(s):  
Prefrontal Cortex ◽  
Acoustic Properties ◽  
Acoustic Features ◽  
Ventrolateral Prefrontal Cortex ◽  
Communication Signals ◽  
First Order ◽  
Natural Stimuli ◽  
Spectrotemporal Receptive Field ◽  
Auditory Objects

Communication is one of the fundamental components of both human and nonhuman animal behavior. Auditory communication signals (i.e., vocalizations) are especially important in the socioecology of several species of nonhuman primates such as rhesus monkeys. In rhesus, the ventrolateral prefrontal cortex (vPFC) is thought to be part of a circuit involved in representing vocalizations and other auditory objects. To further our understanding of the role of the vPFC in processing vocalizations, we characterized the spectrotemporal features of rhesus vocalizations, compared these features with other classes of natural stimuli, and then related the rhesus-vocalization acoustic features to neural activity. We found that the range of these spectrotemporal features was similar to that found in other ensembles of natural stimuli, including human speech, and identified the subspace of these features that would be particularly informative to discriminate between different vocalizations. In a first neural study, however, we found that the tuning properties of vPFC neurons did not emphasize these particularly informative spectrotemporal features. In a second neural study, we found that a first-order linear model (the spectrotemporal receptive field) is not a good predictor of vPFC activity. The results of these two neural studies are consistent with the hypothesis that the vPFC is not involved in coding the first-order acoustic properties of a stimulus but is involved in processing the higher-order information needed to form representations of auditory objects.

Coriolis contribution to the rotatory ether drag

1979 ◽  
Vol 368 (1735) ◽  
pp. 591-592 ◽  
Keyword(s):  
Drag Coefficient ◽  
Coriolis Force ◽  
Faraday Effect ◽  
Opposite Sign ◽  
Electron Motion ◽  
Absolute Value ◽  
The Absolute ◽  
Dispersion Term

The theory of the rotatory ether drag recently discovered by Jones is discussed. It is shown that the existing theories did not take into account the Coriolis force influencing the electron motion. The Coriolis contribution to the rotatory ether drag coefficient is expressed via the Faraday effect constant. The absolute value of the Coriolis term is found to be approximately equal to the dispersion term and to have the opposite sign.

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