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Numerical Simulation of Baroclinic Jovian Vortices
We examine the evolution of baroclinic vortices in a time-dependent, nonlinear numerical model of a Jovian atmosphere. The model uses a normal-mode expansion in the vertical, using the barotropic and first two baroclinic modes. Results for the stability of baroclinic vortices on an f plane in the absence of a mean zonal flow are similar to results of Earth vortex models, although the presence of a fluid interior on the Jovian planets shifts the stability boundaries to smaller length scales. The presence of a barotropic mean zonal flow in the interior stabilizes vortices against instability and significantly modifies the finite amplitude form of baroclinic instabilities. The effect of a zonal flow on a form of barotropic instability produces periodic oscillations in the latitude and longitude of the vortex as observed at the level of the cloud tops. This instability may explain some, but not all, observations of longitudinal oscillations of vortices on the outer planets. Oscillations in aspect ratio and orientation of stable vortices in a zonal shear flow are observed in this baroclinic model, as in simpler twodimensional models. Such oscillations are also observed in the atmospheres of Jupiter and Neptune. The meridional propagation and decay of vortices on a β plane is inhibited by the presence of a mean zonal flow. The direction of propagation of a vortex relative to the mean zonal flow depends upon the sign of the meridional potential vorticity gradient; combined with observations of vortex drift rates, this may provide a constraint on model assumption for the flow in the deep interior of the Jovian planets
A Multi-Dimensional Ranking of Australian Economics Departments
This study uses cluster analysis to classify Australian economics departments into groups that have similar quantities of research output, measured by two publication counts, and similar quality of research output, measured by a citation count. Three groups of departments are identified and factor analysis is used to rank the groups. Whether research output is measured in total or on a per staff basis, Melbourne is in the group that ranks first, the remaining members of the ‘group of eight’ are in one or other of the top two groups, and at least 15 other departments are in the third-ranked group
Market Differentials for Meat Quality Improvement: Meat Standards Australia
Eating quality is one of the most important factors influencing demand for beef. Meat Standards Australia is a voluntary beef grading system aimed at improving consumer certainty about beef quality, improving overall beef quality and strengthening supply chain linkages. Since its inception in 1999/2000, substantial improvements in beef quality, as measured by the system, have been identified. An evaluation was undertaken to estimate the economic value of these improvements to the industry. It was found that MSA graded beef consistently attracted premiums above nongraded beef, with mean values of 29c/kg and 39c/kg (carcass equivalent) at the wholesale and retail levels respectively, while the food service sector received an average of 39c/kg (carcass equivalent). The total retail value of the program to date is estimated to be between 171 million at the wholesale level (in terms of 2005 prices).Livestock Production/Industries,
What makes slow samples slow in the Sherrington-Kirkpatrick model
Using results of a Monte Carlo simulation of the Sherrington-Kirkpatrick
model, we try to characterize the slow disorder samples, namely we analyze
visually the correlation between the relaxation time for a given disorder
sample with several observables of the system for the same disorder sample.
For temperatures below but not too low, fast samples (small relaxation
times) are clearly correlated with a small value of the largest eigenvalue of
the coupling matrix, a large value of the site averaged local field probability
distribution at the origin, or a small value of the squared overlap is more robust) . There is a strong correlation between the values of
the relaxation time for two distinct values of the temperature, but this
correlation decreases as the system size is increased. This may indicate the
onset of temperature chaos
Likelihood informed dimension reduction for inverse problems in remote sensing of atmospheric constituent profiles
We use likelihood informed dimension reduction (LIS) (T. Cui et al. 2014) for
inverting vertical profile information of atmospheric methane from ground based
Fourier transform infrared (FTIR) measurements at Sodankyl\"a, Northern
Finland. The measurements belong to the word wide TCCON network for greenhouse
gas measurements and, in addition to providing accurate greenhouse gas
measurements, they are important for validating satellite observations. LIS
allows construction of an efficient Markov chain Monte Carlo sampling algorithm
that explores only a reduced dimensional space but still produces a good
approximation of the original full dimensional Bayesian posterior distribution.
This in effect makes the statistical estimation problem independent of the
discretization of the inverse problem. In addition, we compare LIS to a
dimension reduction method based on prior covariance matrix truncation used
earlier (S. Tukiainen et al. 2016)
The young massive stellar cluster associated to RCW121
We report NIR broad and narrow band photometric observations in the direction
of the IRAS17149-3916 source that reveal the presence of a young cluster of
massive stars embedded in an HII region coincident with RCW121. These
observations, together with published radio data, MSX and Spitzer images were
used to determine some of the physical parameters of the region. We found 96
cluster member candidates in an area of about 1.5 x 2.0 square arcmin, 30% of
them showing excess emission in the NIR. IRS 1, the strongest source in the
cluster with an estimated spectral type of O5V-O6V ZAMS based on the
color-magnitude diagram, is probably the main ionizing source of the HII region
detected at radio wavelengths. Using the integrated Brgamma and the 5 GHz flux
densities, we derived a mean visual extinction AV=5.49 magnitudes. From the
observed size of the Brgamma extended emission, we calculated the emission
measure E and the electron density ne, characteristic of compact HII regions.Comment: 18 pages, 8 figures, accepted for publication on AJ (February/2006
The Chemical Compositions of the Type II Cepheids -- The BL Her and W Vir Variables
Abundance analyses from high-resolution optical spectra are presented for 19
Type II Cepheids in the Galactic field. The sample includes both short-period
(BL Her) and long-period (W Vir) stars. This is the first extensive abundance
analysis of these variables. The C, N, and O abundances with similar spreads
for the BL Her and W Vir show evidence for an atmosphere contaminated with
-process and CN-cycling products. A notable anomaly of the BL Her
stars is an overabundance of Na by a factor of about five relative to their
presumed initial abundances. This overabundance is not seen in the W Vir stars.
The abundance anomalies running from mild to extreme in W Vir stars but not
seen in the BL Her stars are attributed to dust-gas separation that provides an
atmosphere deficient in elements of high condensation temperature, notably Al,
Ca, Sc, Ti, and -process elements. Such anomalies have previously been seen
among RV Tau stars which represent a long-period extension of the variability
enjoyed by the Type II Cepheids. Comments are offered on how the contrasting
abundance anomalies of BL Her and W Vir stars may be explained in terms of the
stars' evolution from the blue horizontal branch.Comment: 41 pages including 11 figures and 4 tables; Accepted for publication
in Ap
Struvite Crystalluria and Urolithiasis in Cross Labradors
Recurrent struvite crystalluria and urolithiasis in a Cross-Labrador bitch was studied using a combined Coulter-Counter and scanning electron microscope (SEM) approach. Staphylococcus bacteria were cultured from the patient\u27s urine as well as from the calculi themselves. Urine samples were subjected to particle counting and sizing during active and non-active periods of stone formation. Size distribution curves so obtained were identical as were those derived from sterile and non-sterile specimens. These showed a peak incidence at a diameter of 5 μm. Particle sizes for 6 controls were also determined and showed an even distribution over a much wider range with small peaks occurring at 3,10, and 20 μm diameters.
SEM studies of urine sediments revealed the presence of struvite crystals in all the controls as well as in the stone-former. These occurred in a variety of shapes and sizes but were generally larger in the controls. SEM also revealed intimate admixtures of struvite and apatite in calculi surgically removed from the patient.
The results of this study indicate that crystal numbers are of greater significance than crystal size. It is also suggested that Cross-Labradors may be unusually predisposed to struvite crystalluria. The repeated recurrence of struvite urolithiasis in the subject indicates a possible inherent physiological malfunction in the animal\u27s ability to cope with this crystalluria. The absence of a nucleation inhibitor in the stone-farmer\u27s urine is also postulated
The crystal and molecular structure of the bis(4-N, N1-dimethylaminopyridine) solvate of disalicylicacidatobis(nitrotodioxouranium)(VI)
The structure of the title compound [(C7H4NO8U)(C7H11N2)]2 has been determined by Patterson and Fourier methods from single crystal X-ray diffraction data collected on a four-circle diffractometer. Full-matrix least-squares refinement yielded a final conventional R of 0.041 for 2189 reflections. The complex crystallizes in the space group P with a = 11.004(5), b = 9.981(5), c = 9.928(5) Å, α = 119.6(3), β = 107.7(3), γ = 81.9(3)°, Dm = 2.17, Dc = 2.173g cm−3. The structure is dimeric. The uranium atoms are eight-coordinate and are bridged via centrosymmetrically related carboxylic oxygen atoms. The nitrate group is bidentate and the average U---O (ligand) distance is 2.463 Å. Hydrogen bonding of the type N---HO links two dimethyl-aminopyridine molecules to the dimer
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