55 research outputs found
Strong resemblance between surface and deep zonal winds inside Jupiter revealed by high-degree gravity moments
Jupiter's atmosphere-interior is a coupled fluid dynamical system strongly
influenced by the rapid background rotation. While the visible atmosphere
features east-west zonal winds on the order of 100 m/s (Tollefson et al. 2017),
zonal flows in the dynamo region are significantly slower, on the order of 1
cm/s or less, according to the latest magnetic secular variation analysis
(Bloxham et al. 2022). The vertical profile of the zonal flows and the
underlying mechanism remain elusive. The latest Juno radio tracking
measurements afforded the derivation of Jupiter's gravity field to spherical
harmonic degree 40. Here, we use the latest gravity solution to reconstruct
Jupiter's deep zonal winds without a priori assumptions about their latitudinal
profile. The pattern of our reconstructed deep zonal winds strongly resembles
that of the surface wind within 35 degrees latitude from the equator, in
particular the northern off-equatorial jet (NOEJ) and the southern
off-equatorial jet (SOEJ) (Kulowski et al. 2021). The reconstruction features
larger uncertainties in the southern hemisphere due to the north south
asymmetric nature of Juno's trajectory. Amplitude of the reconstructed deep
NOEJ matches that of the surface wind when the wind is truncated at a depth
around 2500 km, and becomes twice that of the surface wind if the truncation
depth is reduced to about 1500 km. Our analysis supports the physical picture
in which prominent part of the surface zonal winds extends into Jupiter's
interior significantly deeper than the water cloud layer.Comment: Accepted for publication in ApJ, 11 pages, 6 figure
True heterotopic bone in the paralyzed patient
In past years the clinical and radiologic presentation of true heterotopic bone in the paralyzed patient has been confused with osteomyelitis, neoplasm, trauma, and thrombophlebitis. We reviewed 376 paralyzed patients' roentgenographic files and found 78 patients with soft tissue ossification unassociated with infection, neoplasm, or underlying fractures, which we called true heterotopic bone. From this population the usual spectrum of radiologic findings is described, so that the radiologist may separate roentgenographically a group of patients from other types of ectopic ossification.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46816/1/256_2004_Article_BF00347167.pd
Acoustic measurements and computer simulation of the interior of st. Mary Magdalene church in Lviv
W pracy omówiono akustyczne aspekty wykorzystania kościoła pod wezwaniem Św. Marii Magdaelny we Lwowie do celów koncertowych. Przedstawiono wyniki pomiarów akustycznych oraz koncepcję poprawy jego walorów akustycznych jako sali koncertowej z wykorzystaniem doraźnie wstawianych do wnętrza elementów, rozpraszających dźwięk i poprawiających wzajemne słyszenie się wykonawców.The paper discusses acoustical aspects of musical activity in St Mary Magdalene church in Lviv. The concept of improving acoustical qualities of the church when employed as a concert hall is presented. Current acoustics of the church meets both liturgical and musical requirements as long as the convention of using it as a historical object is maintained
Applications of the Green Functions in the Study of Acoustic Problems in Open and Closed Spaces.
This paper presents a set of analytical solutions (Green functions) for the steady state response of a homogenous acoustic three-dimensional space subjected to a point harmonic load or a spatially sinusoidal harmonic line load. The propagation medium is modelled with plane surfaces placed so as to reproduce spaces that vary from a simple half-space to a rectangular parallelepiped closed space. The final expressions are implemented to evaluate first the pressure field inside a rectangular parallelepiped room, whose walls allow different absorption coefficients. Then, the acoustic scattering of a three-dimensional sound source by an infinitely long rigid barrier in the vicinity of a tall building is evaluated using the boundary-element method (BEM), making use of the analytical solution for a spatially sinusoidal line source. The use of these Green functions allows the required BEM discretization to be limited to the surface of the barrier, avoiding the discretization of the tall building and ground. The calculations are performed in the frequency domain and time signatures are obtained by means of inverse Fourier transforms. Complex frequencies are used to attenuate the response at the end of the time frame, which is taken into account by rescaling the time response.http://www.sciencedirect.com/science/article/B6WM3-457CSW7-4M/1/1de64d56f8cb502849f24b9c9943633
- …